1990 - SEPTEMBER 1995 141 citations from AGRICOLA by Diane Doyle Water Quality Information Center ************************************************************** This electronic bibliography is intended primarily to provide awareness of recent investigations and discussions of a topic and is not intended to be in-depth and exhaustive. The inclusion or omission of a particular publication or citation should not be construed as endorsement or disapproval. Send suggestions for electronic bibliographies related to water resources and agriculture to wqic@nalusda.gov To locate a publication cited in this bibliography, please contact your local, state, or university library. If you are unable to locate a particular publication, your library can contact the National Agricultural Library (please see "Document Delivery Services" at http://www.nal.usda.gov/ddsb). **************************************************************** EVALUATION OF AGRICULTURAL BEST MANAGEMENT PRACTICES (II) 1. Adoption of nitrogen and water management practices to improve water quality. Supalla, R. J.; Selley, R. A.; Bredeweg, S.; Watts, D. J-soil-water-conserv v.50, p.77-82. (1995). Includes references. Descriptors: zea-mays; irrigated-stands; nitrogen-; crop-management; nitrogen- fertilizers; application-to-land; water-management; nitrate-; leaching- ; losses-from-soil; groundwater-pollution; water-quality; farmers'- attitudes; environmental-protection; nebraska-; nitrogen-management NAL Call No.: 56.8-J822 ***************************************************************** 2. Agricultural use of organic amendments: a historical perspective. Parr, J. F.; Hornick, S. B. Am-J-Alternative-Agric v.7, p.181-189. (1992). Includes references. Descriptors: organic-fertilizers; history-; erosion-; composting-; soil-organic- matter; sewage-sludge; solid-wastes; soil-fertility Abstract: Agricultural research conducted in the United States since establishment of the U.S. Dept. of Agriculture and Land-Grant University System in 1862 has shown that regular and proper additions of organic materials are very important for maintaining the tilth, fertility, and productivity of agricultural soils, protecting them from wind and water erosion, and preventing nutrient losses by runoff and leaching. Several millennia earlier, Roman agriculturists were advocating crop rotations, green manuring, composts, legumes, farmyard manures, crop residues, wood ashes, seaweed, and sewage wastes for supplying humus and nutrients to restore or enhance soil productivity. Even earlier, Asian farmers also used these practices to maintain healthy and productive soils. Today the most serious problem in U.S. agriculture and agriculture worldwide is the widespread degradation of agricultural soils through erosion and the consequential decline in productivity. In view of how much information is available on the benefits of organic recycling on agricultural lands, one wonders why we aren't doing a better job of protecting and conserving our land resource base. We discuss strategies for using organic resources more effectively to achieve a more sustainable agriculture for the future. NAL Call No.: S605.5.A43 ***************************************************************** 3. Agriculture and water quality in the Great Plains: status and recommendations. Misc-publ,-Tex-Agric-Exp-Stn. College Station, Tex. : Texas Agricultural Experiment Station. Mar 1992. (1738) 34 p. Includes references. Descriptors: water-quality; agricultural-chemicals; water-pollution; groundwater- ; surface-water; irrigation-; livestock-farming; conservation-tillage; agricultural-planning; state-government; federal-government; agricultural-research; agricultural-policy; legislation-; agricultural- regions; northern-plains-states-of-usa; southern-plains-states-of-usa; mountain-states-of-usa NAL Call No.: 100-T31M ***************************************************************** 4. Analysis of on-farm best management practices in the Everglades Agricultural Area. Willis, L. M.; Forrest, S. B.; Nissen, J. A.; Hiscock, J. G.; Kirby, P. V. Environmentally sound agriculture proceedings of the second conference 20-22 April 1994 / p.93-99. (1994). Includes references. Descriptors: marshes-; environmental-protection; agricultural-land; management-; cost-effectiveness-analysis; phosphorus-; discharge-; water-flow; water- quality; improvement-; sustainability-; florida-; nutrient-loadings NAL Call No.: S589.7.E57-1994 ***************************************************************** 5. Animal waste system management in Southwest Missouri. Feistner, J. Pap-Am-Soc-Agric-Eng. St. Joseph, Mich. : American Society of Agricultural Engineers,. Winter 1991. (914570) 10 p. Paper presented at the "1991 International Winter Meeting sponsored by the American Society of Agricultural Engineers," December 17-20, 1991, Chicago, Illinois. Descriptors: animal-manures; animal-wastes; water-quality; environmental-impact; missouri- NAL Call No.: 290.9-Am32P ***************************************************************** 6. Application of GLEAMS to predict nutrient losses from land application of poultry litter. Yoon, K. S.; Yoo, K. H.; Wood, C. W.; Hall, B. M. Trans-ASAE v.37, p.453-459. (1994). Includes references. Descriptors: poultry-manure; runoff-; nitrogen-; phosphorus-; water-quality; simulation-models; alabama-; groundwater-loading-effects-of-agricul; -manage; -systems Abstract: The GLEAMS (Groundwater Loading Effects of Agricultural Management System) (version 2.1) water quality model was used to predict nutrient (N and P) losses in surface and subsurface runoff, and their concentrations in soil layers, following application of two rates (9 and 18 t ha-1) of poultry litter and a recommended rate of a commercial fertilizer on conventionally tilled corn plots at the Tennessee Valley Substation of the Alabama Agricultural Experiment Station. Model simulation results were compared with field data. The experiment included four replications for each of the three soil-amendment treatments. The GLEAMS simulation of soluble and sediment P losses in surface runoff and NO3-N concentrations in leachate and soil layers were not consistent with field data. Simulation of N-transformation effects on N losses in surface runoff did not agree with field data. The model simulated higher NH4-N than NO3-N losses in surface runoff, while field data showed the opposite. The model simulated low concentrations of P in leachate at a 1.0 m depth, while the observed data showed large variations. NAL Call No.: 290.9-Am32T ***************************************************************** 7. Assessing phosphorus bioavailability in agricultural soils and runoff. Sharpley, A. N. Fertil-res. Dordrecht : Kluwer Academic Publishers. 1993. v. 36 (3) p. 259-272. Includes references. Descriptors: phosphorus-; bioavailability-; estimation-; agricultural-soils; runoff-; analytical-methods; iron-oxides; water-quality; eutrophication- ; risk-; no-tillage-; tillage-; watershed-management; algae-; nutrient- availability; conventional-tillage; iron-oxide-strips Abstract: Bioavailable phosphorus (BAP) transported in agricultural runoff can accelerate surface water eutrophication. Although several algal assays and chemical extractions have been proposed to estimate BAP, procedural and theoretical limitations have restricted widespread BAP measurement. Thus, a routine method was developed to estimate BAP, which uses iron oxide-impregnated paper strips (Fe-oxide strips) as a P- sink for BAP in runoff. In the proposed method BAP is determined by shaking 50 mL of unfiltered runoff with one Fe-oxide strip for 16 h. Phosphorus is removed from the strip by 0.1 M H2SO4 and measured. The BAP content of runoff from 20 agricultural watersheds in the Southern Plains was related to the growth of P-starved algae incubated for 29 d with runoff as the sole source of P. Acting as a P sink, Fe-oxide strips may have a stronger theoretical basis than chemical extraction in estimating BAP. The method may also have potential use as an environmental soil P test to indicate soils liable to enrich runoff with sufficient P to accelerate eutrophication. Bioavailable P loss in runoff was lower from no till (438 g ha-1 yr-1) than from conventional till (1288 g ha-1 yr-1). Kinetic and enrichment ratio approaches accurately predicted (r2 of 0.93) BAP transport in runoff during 1988 to 1990. Use of the Fe-oxide strip method will facilitate estimation of BAP transport in runoff and thereby, improve assessment of the resultant impact on the biological productivity of receiving surface waters. NAL Call No.: S631.F422 ***************************************************************** 8. Assessment of management practices for reducing pesticide runoff from sloping cropland in Illinois. Felsot, A. S.; Mitchell, J. K.; Kenimer, A. L. J-Environ-Qual v.19, p.539-545. (1990). Includes references. Descriptors: alachlor-; carbofuran-; terbufos-; runoff-; losses-from-soil; sediment-; runoff-water; conservation-tillage; no-tillage-; chiselling- ; ridging-; plowing-; contour-cultivation; row-orientation; sloping- land; zea-mays; glycine-max; illinois-; strip-till- Abstract: The influence of tillage system and contouring practice on runoff of soil-applied alachlor [2-chloro-2',6'-diethyl-N-(methoxymethyl) acetanilide], carbofuran (2,3-dihydro-2,2-dimethyl-7-benzofuranyl methylcarbamate), and terbufos (S-[(tert-butylthio)methyl] O,O-diethyl phosphorodithioate) from small plots (30 m2) were studied using a rainfall simulator. Plots were planted in corn (Zea mays L.) in 1983, soybean [Glycine max (L.) Merr.] in 1984, and corn in 1985. Runoff was measured during a 60-min event with a rainfall intensity of 63 mm/h. During 1984, moldboard-plowed and no-till systems were studied with rows oriented on the contour or up-and-down slope (7-11% slope). Compared to moldboard plow, up-and-down slope no-till and contouring significantly reduced runoff of carbofuran and alachlor. Percentage of applied carbofuran lost in runoff and sediment ranged from 1% (contoured moldboard) to 11% (up-and-down slope moldboard). Percentage of applied alachlor lost ranged from 1% (contoured no-till) to 2% (contoured moldboard). During 1985, the effects of row orientation were evaluated on moldboard-plow, chisel-plow, ridge-till, strip-till, and no-till systems. Under up-and-down slope conditions, runoff of alachlor and terbufos plus two metabolites (terbufos sulfoxide and terbufos sulfone) was significantly reduced by strip-till (< 1% loss) compared to moldboard-plow (6% loss). Larger losses of alachlor (2% of applied) from up-and-down slope no-till than from the other conservation tillage systems 1% or less) was attributed to high concentrations in runoff associated with extensive washoff of the herbicide from soybean crop residues. With contouring, ridge tillage also was effective in reducing pesticide runoff (< 1% of applied pesticide), and strip-till held losses to < 0.1%. Alachlor and carbofuran were translocated from plots largely in moving water, but terbufos and metabolites were recovered mainly in eroded sediment. Although, no conservation tillage system completely eliminated esticide runoff, losses were most effectively minimized by contoured strip-till and no-till, which controlled both water and sediment movement. NAL Call No.: QH540.J6 ***************************************************************** 9. Atrazine leaching and its relation to percolation of water as influenced by three rates and four methods of irrigation water application. Troiano, J.; California. Environmental Hazards Assessment Program. Worker Safety. Environmental Monitoring and Pest Management Branch. Sacramento, Calif. : State of California, Dept. of Food and Agriculture, Division of Pest Management, Environmental Protection and Worker Safety, Environmental Monitoring and Pest Management Branch, [1990] vi, 51 p. : ill.. "July, 1990.". Descriptors: Soils-California-Herbicide-movement; Soil-percolation-California; Groundwater-Pollution-California; Atrazine- NAL Call No.: S592.6.H47A87--1990 ***************************************************************** 10. Barley performance under heavy applications of cattle feedlot manure. Chang, C.; Sommerfeldt, T. G.; Entz, T. Agron-j v.85, p.1013-1018. (1993). Includes references. Descriptors: hordeum-vulgare; cattle-manure; feedlot-wastes; waste-utilization; application-rates; clay-loam-soils; application-date; timing-; incorporation-; tillage-; crop-yield; grain-; yield-increases; irrigated-conditions; dry-conditions; soil-pollution; water-pollution; alberta- Abstract: Approximately 4800 cattle feedlots currently operate in Alberta, Canada. The large amount of manure produced annually creates disposal problems for feedlot operators. The objective of the present study was to evaluate the effects of long-term annual manure application on barley (Hordeum vulgare L.) performance grown on clay loam soil (Dark Brown Chernozemic, Typic Haploboroll) near Lethbridge, AB. Feedlot cattle manure was applied annually from 1973 to 1989 to irrigated plots at 0, 60, 120, and 180 Mg ha-1 (wet wt. basis) and to nonirrigated plots at 0, 30, 60, and Mg ha-1. Manure was incorporated with a cultivator plus disk, rototiller, or plow. Method of incorporation did not affect barley yields, but timeliness and amount of precipitation in the current and previous year were important in determining barley response to manure treatments. When moisture conditions were below normal, manure at any rate of application had a negative effect on yield of nonirrigated barley. Under nonirrigated conditions, average barley yield was depressed by 10 and 16% for the 60 and 90 Mg ha-1 manure rates, respectively. Barley yield increased when manure was applied under irrigation, with the 60 Mg ha-1 rate producing a 20% higher average yield than the control. Although manure was disposed of annually on the soil at up to three times the recommended rate without reducing barley yields below those of the unmanured plots under irrigated conditions, such practice is not recommended because of potential soil and water pollution. NAL Call No.: 4-AM34P ***************************************************************** 11. Beef cattle feedlot manure management. Eghball, B.; Power, J. F. J-soil-water-conserv v.49, p.113-122. (1994). Includes references. Descriptors: beef-cattle; cattle-manure; feedlot-wastes; waste-utilization; resource-management; uses-; application-to-land; environmental-impact; environmental-protection; nitrogen-; recovery-; pollution-control; nutrient-conservation NAL Call No.: 56.8-J822 ***************************************************************** 12. Best management practices (BMP) evaluation using GIS-CREAMS linkage. Bekdash, F. A.; Shirmohammadi, A.; Magette, W. L.; Ifft, T. H. Pap-Am-Soc-Agric-Eng. St. Joseph, Mich. : American Society of Agricultural Engineers,. Winter 1991. (91-7516) 20 p. Paper presented at the "1991 International Winter Meeting sponsored by the American Society of Agricultural Engineers," December 17-20, 1991, Chicago, Illinois. Descriptors: pollution-; geographical-information-systems; algorithms- NAL Call No.: 290.9-Am32P ***************************************************************** 13. Best management practices for agricultural nonpoint source control. IV, Pesticides : for the project Rural Nonpoint Source Control Water Quality Evaluation and Technical Assistance (National Water Quality Evaluation Project). United States. Environmental Protection Agency. Office of Research and Development. Washington, DC : U.S. Environmental Protection Agency, Office of Research and Development, [1992] xiii, 87 p.. Shipping list no.: 92-268-P. Descriptors: Rural-Nonpoint-Source-Control-Water-Quality-Evaluation-and- Technical-Assistance-Project; Pesticides- NAL Call No.: TD427.P35B46-1992 ***************************************************************** 14. Best management practices for forested wetlands in the Southern Appalachian Region. Aust, W. M. Water-air-soil-pollut v.77, p.457-468. (1994). In the special issue: Wetlands of the interior southeastern United States / edited by C.C. Trettin, W.M. Aust, and J. Wisniewski. Conference on "Wetland Ecology, Management, and Conservation," held September 28-30, 1993, Knoxville, Tennessee. Descriptors: wetlands-; riparian-forests; bottomland-forests; forest-management; environmental-degradation; protection-of-forests; forestry-practices; environmental-impact; logging-effects; southeastern-states-of-usa; appalachian-states-of-usa NAL Call No.: TD172.W36 ***************************************************************** 15. Biogeochemical responses of a forested watershed to both clearcut harvesting and papermill sludge application. Kraske, C. R.; Fernandez, I. J. J-environ-qual v.22, p.776-786. (1993). Includes references. Descriptors: paper-mill-sludge; application-to-land; forests-; watersheds-; clearcutting-; forest-soils; pinus-resinosa; soil-ph; soil-organic- matter; calcium-; magnesium-; cation-exchange-capacity; sulfates-; biogeochemistry-; maine- Abstract: The biogeochemical responses of a forested watershed to both clearcut harvesting and papermill sludge application were evaluated. A mixed northern hardwood and conifer stand in Letter E Township, ME, was clearcut during the winter of 1985-1986. Harvest residues were windrowed, and red pine (Pinus resinosa Aiton) seedlings were planted. In 1987, herbicide was applied to reduce vegetative competition. In the fall of 1989, a combined primary and secondary papermill sludge was operationally applied with a rate of 40 Mg ha-1 (dry sludge). Actual loading rates varied considerably. Study plots were established in sludge-harvest, control-harvest, and uncut forest zones. Soils within the treatment zones consisted of Typic Haplorthods developed from loamy basal tills. Selected soil and soil solution properties were measured in 1989 and 1990. In 1989, harvest area forest floor pH was 0.6 to 0.8 units higher, and organic matter content was up to 40% lower, when compared with that of the uncut forest area. This reflected the accelerated decomposition of the forest floor as a result of the harvest activities. Sludge application further increased forest floor pH by approximately one unit, exchangeable Ca2+ and Mg2+ by approximately 100 and 60%, respectively, cation-exchange capacity by 60%, and base saturation by 34% compared with that of the control-harvest area. Exchangeable Mg2+ and Na+, and water-soluble SO4(- 2) were the mineral soil properties most affected by sludge application. Harvesting increased concentrations of major. times greater, and Mg2+ was three to six times greater in the harvest area than in the uncut forest area. Flushes of Ca2+, Mg2+, Na+, and SO4(-2) into soil solution occurred immediately following sludge application. Only Na+ and SO4(-2) remained elevated in 1990, being five and three times greater, respectively, in the sludge amended harvest area than in the uncut forest area. Compared with the harvest operations, one-time papermill sludg application appeared to have only small effects on the biogeochemical processes of the treated Letter E site. NAL Call No.: QH540.J6 ***************************************************************** 16. BMP impacts on watershed runoff, sediment, and nutrient yields. Park, S. W.; Mostaghimi, S.; Cooke, R. A.; McClellan, P. W. Water-resour-bull v.30, p.1011-1023. (1994). Includes references. Descriptors: watersheds-; pollution-; runoff-; sediment-; nutrients-; water- quality; catchment-hydrology; virginia-; best-management-practice; agricultural-nonpoint-source-pollution Abstract: To quantify the effectiveness of best management practice (BMP) implementation on runoff, sediment, and nutrient yields from a watershed, the Nomini Creek watershed and water quality monitoring project was initiated in 1985, in Westmoreland County, Virginia. The changes in nonpoint source (NPS) loadings resulting from BMPs were evaluated by comparing selected parameters from data series obtained before, during, and after periods of BMP implementation. The results indicated that the watershed-averaged curve number, sediment, and nutrient (N and P) concentrations were reduced by approximately 5, 20, and 40 percent, respectively, due to BMP implementation. The nutrient yield model developed by Frere et al. (1980) was applied to the water quality parameters from 175 storms, but it failed to adequately describe the observed phenomena. Seasonal changes in nutrient availability factors were not consistent with field conditions, nor were they significantly different in the pre- and post-BMP periods. An extended period of monitoring, with intensive BMP implementation over a larger portion of the watershed, is required to identify RMP effectiveness. NAL Call No.: 292.9-Am34 ***************************************************************** 17. BMPs for water quality : best management practices to reduce runoff of pesticides into surface water : a review and analysis of supporting research. Best management practices to reduce runoff of pesticides into surface water. Christensen, B.; Conservation Technology Information Center. [West Lafayette, Ind.] : Conservation Technology Information Center, [1992 or 1993?] i, 43 p. : ill.. Cover title. Descriptors: Pesticides-Environmental-aspects-United-States; Water-Pollution- United-States; Agricultural-pollution-United-States-Management NAL Call No.: TD427.P35B57--1992 ***************************************************************** 18. Changes in physical and chemical characteristics of poultry litter due to rotary tilling. Koon, J. L.; Flood, C. A. Jr.; McCaskey, T. A.; Brewer, R. N. Trans-ASAE v.37, p.269-274. (1994). Includes references. Descriptors: poultry-manure; litter-; rotary-cultivators; physical-properties; chemical-properties Abstract: Pine shavings poultry litter from four growouts were analyzed for particle size distribution and chemical composition for untilled litter and litter that had been tilled three times following each growout. Little change in the particle size distribution was observed after the first growout for either treatment. The majority of the nutrient mass was associated with the larger size particles (those failing to pass a No. 50 screen) while the percent element analysis increased with the smaller size fractions for both treatments. Little change in nutrient content was observed between treatments, but the tilled liner had an increase in percent ash content and a decrease in percent crude fiber. No difference was observed in the crude protein percentage in the two treatments. NAL Call No.: 290.9-Am32T ***************************************************************** 19. Changing farm practice to meet environmental objectives of nutrient loss to Oyster Harbour. Weaver, D. M.; Prout, A. L. Fertil-res. Dordrecht : Kluwer Academic Publishers. 1993. v. 36 (2) p. 177-184. In the special issue: Fertilizers and eutrophication in South- Western Australia / edited by E.P. Hodgkin and J.S. Yeates. Descriptors: watershed-management; agricultural-land; nutrients-; phosphorus-; losses-from-soil; point-sources; farm-management; environmental- management; water-quality; eutrophication-; western-australia; on-farm-nutrient-management; nonpoint-sources Abstract: Eutrophication problems in waterbodies in south-western Australia are primarily caused by inputs of nutrients from diffuse sources within the agricultural catchments of these waterbodies. To reduce the algal growth and seagrass decline caused by these inputs, it is essential to modify land management to minimize nutrient losses. Permanent reduction in nutrient losses from agricultural catchments should involve voluntary changes in farm management practices based on improved land management. Specifically, these include on-farm nutrient management such as soil testing, fertilizer management, the use of perennial plants, and water and erosion control measures to reduce nutrient loss from rural land. This paper describes the management of nutrient loss from the catchment of Oyster Harbour on the south coast of Western Australia using a co-operative approach. NAL Call No.: S631.F422 ***************************************************************** 20. A comparative study of nitrate leaching from soils of differing textures under similar climatic and cropping conditions. Vinten, A. J. A.; Vivian, B. J.; Wright, F.; Howard, R. S. J-hydrol v.159, p.197-213. (1994). Special Issue: Field laboratory and modelling studies of flow and transport processing / edited by H.S. Wheater, P.A.C. Raats, and A.C. Armstrong. Sciences Programme Session HS1 of the XVII General Assembly of the European Geophysical Society, April 6-10, 1992, Edinburgh. Descriptors: nitrate-nitrogen; leaching-; sandy-soils; clay-loam-soils; nitrogen- fertilizers; application-rates; hordeum-vulgare; cultivation-; timing-; drainage-water; flow-to-drains; losses-from-soil; groundwater-pollution Abstract: This study reports a direct comparison of nitrate leaching on a field scale from a sandy soil overlying a relatively impermeable glacial till (Ksat = 30-50 mm day-1), with that from a clay loam soil overlying a similar glacial till (Ksat = 2-8 mm day-1), under nearly identical climatic and cropping conditions. Drained plots were installed at each site, and N application rate on the plots, which grew spring barley, varied from 0 to 210 kg N ha-1. Nitrate concentrations in drainage water from the two sites were measured using a simple flow- weighted sampling device and drainflow was measured using tipping bucket flow meters. Total leaching losses (including an estimate of deep percolation) in the first year of the comparison were not significantly higher on the sandy site (38 +/- 11 kg N ha-1 at 150 kg N ha-1 N fertiliser application) than on the clay loam site (27 +/- 4 kg N ha-1). In the subsequent 2 years, leaching losses increased at the sandy loam site. At the clay loam site leaching losses were much lower (7-11 kg N ha-1 in the final year). Timing of cultivation was an important factor influencing the amount of leaching in the clay loam soil. The effect of applied N fertiliser on nitrate leaching was small at both sites, except in the final year at the sandy site, which leached 105 kg N ha-1 at the highest fertiliser rate. The interpretation of these results was aided by concurrent chloride leaching experiments. These experiments showed that the residence time of a substantial proportion of chloride (40-50%) was longer than 1 year. This may be because of diffusion and slow convection into the glacial till horizons, where the residence time is long. NAL Call No.: 292.8-J82 ***************************************************************** 21. Components of dairy manure management systems. Van Horn, H. H.; Wilkie, A. C.; Powers, W. J.; Nordstedt, R. A. J-dairy-sci v.77, p.2008-2030. (1994). Includes references. Descriptors: cattle-manure; dairy-farms; application-to-land; dairy-cows; excretion-; waste-treatment; waste-disposal; waste-utilization; energy- balance; water-use; ammonia-; methane-; nitrogen-; phosphorus- Abstract: Dairy manure management systems should account for the fate of excreted nutrients that may be of environmental concern. Currently, regulatory oversight is directed primarily at the assurance of water quality; N is the most monitored element. Land application of manure at acceptable fertilizer levels to crops produced on the farm by hauling or by pumping flushed manure effluent through irrigation systems is the basis of most systems. Nutrient losses to surface and groundwaters can be avoided, and significant economic value can be obtained from manure as fertilizer if adequate crop production is possible. Dairies with insufficient crop production potential need affordable systems to concentrate manure nutrients, thereby reducing hauling costs and possibly producing a salable product. Precipitation of additional nutrients from flushed manures with sedimented solids may be possible. Composting of separated manure solids offers a possible method to stabilize solids for distribution, but, most often, solids separated from dairy manures are fibrous and low in fertility. Manure solids combined with wastes from other sources may have potential if a marketable product can be produced or if sufficient subsidy is received for processing supplementary wastes. Solutions to odor problems are needed. Energy generated from manure organic matter, via anaerobic digestion, reduces atmospheric emissions of methane and odorous compounds. Use of constructed wetlands or harvesting of photosynthetic biomass from wastewater has the potential to improve water quality, making extensive recycling possible. NAL Call No.: 44.8-J822 ***************************************************************** 22. Concepts and practices for improving nitrogen management for vegetables. Hochmuth, G. J. HortTechnology v.2, p.121-125. (1992). Proceedings of the Workshop, "Fertilizer in Horticultural Crops: Implications for Water Pollution," held at the 88th ASHS Annual Meeting, July 24, 1991, Pennsylvania State University, University Park. Descriptors: nitrogen-fertilizers; vegetables-; crop-production; water- management; groundwater-pollution; organic-amendments; nitrification- inhibitors; cultivars-; cropping-systems; trickle-irrigation; plant- analysis; literature-reviews; southeastern-states-of-usa NAL Call No.: SB317.5.H68 ***************************************************************** 23. Conservation tillage a sustainable agricultural practice. Lakshminarayan, P. G.; Bouzaher, A.; Johnson, S. R. Environmentally sound agriculture proceedings of the second conference 20-22 April 1994 / p.139-146. (1994). Includes references. Descriptors: zea-mays; glycine-max; continuous-cropping; rotations-; conservation-tillage; tillage-; environmental-impact; sustainability-; erosion-; erosion-control; nitrate-nitrogen; losses-from-soil; leaching- ; runoff-; water-quality; simulation-models; statistical-analysis; conventional-tillage; metamodels- NAL Call No.: S589.7.E57-1994 ***************************************************************** 24. Conservation tillage: an ecological approach to soil management. Blevins, R. L.; Frye, W. W. Adv-agron. San Diego, Calif. : Academic Press. 1993. v. 51 p. 33-78. Includes references. Descriptors: conservation-tillage; no-tillage-; soil-management; soil- conservation; water-conservation; water-quality; energy-consumption; soil-organic-matter; soil-physical-properties; soil-water; infiltration- ; evaporation-; herbicides-; weed-control; insect-control; plant- disease-control; soil-fertility; soil-temperature; soil-ph; acidification-; literature-reviews NAL Call No.: 30-Ad9 ***************************************************************** 25. Conservation tillage and environmental issues. Schertz, D. L. Yearb-agric. Washington, D.C. : U.S. Dept. of Agriculture : For sale by the Supt. of Docs., U.S. G.P.O., [1980-. 1991. p. 15-20. In the series analytic: Agriculture and the Environment / edited by D. Takiff Smith. Descriptors: conservation-tillage; erosion-control; environmental-impact; water- pollution; agricultural-chemicals; movement-in-soil; losses-from-soil NAL Call No.: 1-Ag84y ***************************************************************** 26. Corn yield and nitrogen uptake as influenced by tillage and applied nitrogen. Menelik, G.; Reneau, R. B. Jr.; Martens, D. C. J-plant-nutr v.17, p. 911-913. (1994). Includes references. Descriptors: zea-mays; tillage-; no-tillage-; urea-ammonium-nitrate; application- rates; split-dressings; sewage-sludge; sewage-products; nutrient- uptake; crop-yield; nitrogen-; conventional-tillage Abstract: No-till management systems have been reported to reduce nonpoint source (NPS) pollution from agricultural fields. However, questions have been raised concerning the fate of nitrogen (N) in these systems. increased moisture conservation and reduced runoff from no-till systems have the potential to accelerate leaching of nitrate (NO3) out of the root zone, thus altering the problem from one of surface water degradation to one of ground water pollution. However, it is also probable that the additional moisture conserved in no-till systems result in increased crop yield and N uptake. Time of N application and source of N could influence yield and N recovery and thus limit N losses during critical periods. A 3-year study was conducted to determine if the fate of N applied to nonirrigated corn (Zea mays L.) would be influenced by tillage system, N rate, and time and source of N application. This paper addresses the impact of these practices on yield and N uptake. The experimental site was located on a Typic Hapludult that is characteristic of finer-textured soils used for continuous corn production. Management practices evaluated were conventional-till vs. no-till, rate of N application, inorganic N vs. sewage sludge N, and preplant vs. split application of N. Yield and N recovery were, respectively, 19 and 22% higher in no-till compared with conventional-till systems at the point of maximum yield. Corn yield and N uptake were both increased when sewage sludge was applied compared with either split or preplant application of inorganic N. No differences were observed in corn yield and N uptake between preplant and split application of N. These studies were conducted. indicate that the higher moisture present in the no-till system may have contributed to increased yield and N recovery. The increased N recovery reduces the quantity of N remaining in the soil profile that might be lost, due to leaching, after crop harvest. NAL Call No.: QK867.J67 ***************************************************************** 27. Crop, soil, and management effects on phosphorus soil test levels. Pierzynski, G. M.; Logan, T. J. J-prod-agric v.6, p.513-520. (1993). Paper presented at the "Symposium on assessment of potential phosphorus losses from a field site", November 4, 1992, Minneapolis, Minnesota. Descriptors: phosphorus-; soil-test-values; variation-; crops-; soil-; crop- management; soil-management; site-factors; losses-from-soil; water- pollution; risk-; indexes-; phosphorus-index NAL Call No.: S539.5.J68 ***************************************************************** 28. Cyclic and blending strategies for using nonsaline and saline waters for irrigation. Bradford, S.; Letey, J. Irrig-sci. Berlin, W. Ger. : Springer International. 1992. v. 13 (3) . Includes references. Descriptors: medicago-sativa; zea-mays; gossypium-hirsutum; rotations-; continuous-cropping; salt-tolerance; irrigation-; blending-; cycling-; irrigation-water; saline-water; salinity-; water-quality; simulation- models; dry-matter-accumulation; electrical-conductivity; mathematical- models Abstract: Large quantities of saline water frequently exist in irrigated areas of the world. Various strategies have been proposed to use these saline waters. Blending involves mixing saline water with good quality water to an acceptable salinity and then using this water to irrigate crops. The cyclic strategy uses waters of various salinities separately either during one season or in a crop rotation as a function of the crop's salt tolerance. A multi-seasonal transient state model, known as the modified van Genuchten-Hanks model, was used to investigate the effects of cyclic or blending application of irrigation waters of two salinity levels on alfalfa (Medicago sativa L.), and on a corn (Zea mays L.) and cotton (Gossypium hirsutum L.) crop rotation. Simulated alfalfa yields were similar for the cyclic and blending strategies that applied the same amount of salt and water. The cyclic strategy produced higher simulated yields of salt-sensitive corn than the blending strategy, whereas the simulated salt-tolerant cotton yield was not affected by the two strategies. The beneficial effects of the cyclic strategy on corn production decreased under deficit irrigation. NAL Call No.: S612.I756 ***************************************************************** 29. Dairy manure and plant nutrient management issues affecting water quality and the dairy industry. Lanyon, L. E. J-dairy-sci v.77, p.1999-2007. (1994). Includes references. Descriptors: cattle-manure; water-pollution; pollution-control; dairy-farms; cattle-feeding; production-costs; environmental-policy; usa- Abstract: Specific requirements for dairy manure management to protect water quality from nutrient pollution depend on the organization of individual farms. Further, the management requirements and options are different for point (farmstead) and nonpoint (field-applied) sources of pollution from farms. A formal management process can guide decisions about existing crop nutrient utilization potential, provide a framework for tracking nutrients supplied to crops, and identify future requirements for dairy manure management to protect water quality. Farm managers can use the process to plan daily activities, to assess annual nutrient management performance, and to chart future requirements as herd size increases. Agronomic measures of nutrient balance and tracking of inputs and outputs for various farm management units can provide the quantitative basis for management to allocate better manure to fields, to modify dairy rations, or to develop alternatives to on- farm manure application. Changes in agricultural production since World War II have contributed to a shift from land-based dairy production to a reliance on capital factors of production supplied by the dairy industry. Meanwhile, management of dairy manure to meet increasingly stringent water quality protection requirements is still a land-based activity. Involving the dairy industry and off-farm stakeholders as participants in the management process for field, farm, and regional dairy production can be the basis for decision-making to reconcile the sometimes conflicting demands of production and water quality protection. NAL Call No.: 44.8-J822 ***************************************************************** 30. Design of forest riparian buffer strips for the protection of water quality : analysis of scientific literature. Analysis of scientific literature. Belt, G. H.; O'Laughlin, J.; Merrill, T.; Idaho Forest, W. a. R. P. A. G. Moscow, ID : Idaho Forest, Wildlife and Range Policy Analysis Group, [1992] iv, 35 p.. "June 1992.". Descriptors: Riparian-ecology-Idaho; Riparian-forests-Idaho; Fishes-Idaho-Effect- of-logging-on; Fishes-Idaho-Effect-of-water-quality-on NAL Call No.: QH541.5.R52B44--1992 ***************************************************************** 31. Desing, installation, and performance of percolation lysimeters for water quality sampling. Klocke, N. L.; Todd, R. W.; Hergert, G. W.; Watts, D. G.; Parkhurst, A. M. Trans-A-S-A-E v.36, p.429-435. (1993). Literature review. Descriptors: irrigation-; leachates-; lysimeters-; percolation-; water-quality; zea-mays; literature-reviews; nebraska- Abstract: Lysimeters are the primary research tool for measuring percolation and water quality. Monolithic percolation lysimeters were evaluated for measuring the quantity and quality of leachate from the root zone of irrigated crops. Six percolation lysimeters were installed in a continuous corn (Zea mays L.) cropping system near North Platte, Nebraska, during the fall of 1988 and spring 1989. The lysimeters were 0.9 m in diameter and 2.4 m deep. They were filled with undisturbed soil using a hydraulic pull-down method. Porous stainless steel extractors were installed vertically upward into the lysimeter bottoms, and leachate was extracted from the unsaturated soil. Leachate volume, volumetric soil water content, soil temperature, and soil bulk density were measured. Isolation of a large soil monolith in the lysimeter did not significantly affect plant growth, soil bulk density, or temperature. Soil water content near the lysimeter bottoms was greater than in the surrounding field after a wet spring in 1991. However, extractors removed most excess water and adequately matched unsaturated drainage in the field. Though leachate varied among lysimeters, they behaved similarly over time. Results will help relate irrigation management and scheduling strategies to potential leaching of soil water and associated chemicals into groundwater. NAL Call No.: 290.9-AM32T ***************************************************************** 32. Development and implementation of the Virginia agronomic land use evaluation system (values). Donohue, S. J.; Simpson, T. W.; Baker, J. C.; Monnett, M. M.; Hawkins, G. W. Commun-soil-sci-plant-anal. New York, N.Y. : Marcel Dekker. 1994. v. 25 (7/8) p. 1103-1108. Paper presented at the 1993 International Symposium on Soil Testing and Plant Analysis: Precision Nutrient Management, August 14-19, 1993, Olympia, Washington. Part 1. Descriptors: fertilizer-requirement-determination; soil-testing; nutrients-; management-; databases-; land-use; land-evaluation; water-quality; environmental-protection; water-pollution; pollution-control; point- sources; virginia-; nutrient-management; nonpoint-source-pollution; values-database NAL Call No.: S590.C63 ***************************************************************** 33. Dynamic simulation modelling for evaluating water quality response to agricultural BMP implementation. Cassell, E. A.; Clausen, J. C. Water-sci-technol v.28, p.635-648. (1993). Paper presented at the IAWQ First International Conference on "Diffuse (Nonpoint) Pollution: Sources, Prevention, Impact, Abatement." September 19-24, 1993, Chicago, Illinois. Descriptors: agricultural-land; phosphorus-; input-output-analysis; movement-in- soil; groundwater-pollution; surface-water; pollution-; sources-; dynamic-models; simulation-models; vermont-; best-management-practices NAL Call No.: TD420.A1P7 ***************************************************************** 34. An economic analysis of cover crop use in Georgia to protect groundwater quality. Jordan, J. L.; Morgan, S. L.; Elnagheeb, A. H. Res-bull-Univ-Ga,-Coll-Agric,-Exp-Stn. Athens, Ga. : The Stations, 1967-. June 1994. (419) 13 p. Includes references. Descriptors: cover-crops; leaching-; groundwater-; nitrates-; nitrogen-; fertilizers-; cost-benefit-analysis; secale-cereale; georgia- NAL Call No.: S51.E2 ***************************************************************** 35. Economic and environmental considerations for nitrogen management in the mid-Atlantic coastal plain. Norris, P. E.; Shabman, L. A. Am-J-Alternative-Agric v.7, p.148-156. (1992). Includes references. Descriptors: crop-production; nitrogen-; organic-fertilizers; rotations-; poultry-manure; cost-benefit-analysis; water-quality; virginia- Abstract: A case study in eastern Virginia provides evidence that both environmental and farm profit goals may be satisfied by alternative nitrogen (N) management strategies for grain production. We used a linear programming framework with an N mass balance model to calculate returns from several options for providing N to crops. Replacing single applications of inorganic N fertilizer with split applications or with additions of organic N were found to reduce the potential for N loss from cropland and to increase net returns. For some N management strategies, however, adaption may require financial and educational assistance. As a result, water quality policies may benefit by including such incentives. NAL Call No.: S605.5.A43 ***************************************************************** 36. Economic and environmental effects of nitrogen testing for fertilizer management. Bosch, D. J.; Fuglie, K. O.; Keim, R. W.; United States. Dept. of Agriculture. Economic Research Service. Resources and Technology Division. [Washington, D.C.] : Economic Research Service, Resources and Technology Division, [1994] iv, 37 p. : ill., map. Cover title. Descriptors: Nitrogen-fertilizers-United-States; Water-quality-United-States NAL Call No.: aS651.B67--1994 ***************************************************************** 37. Effect of conventional vs. no-tillage on pesticide leaching to shallow groundwater. Isensee, A. R.; Nash, R. G.; Helling, C. S. J-Environ-Qual v.19, p.434-440. (1990). Includes references. Descriptors: atrazine-; metabolites-; alachlor-; cyanazine-; carbofuran-; leaching-; groundwater-pollution; no-tillage-; tillage-; zea-mays; maryland-; deethylatrazine- Abstract: A field site was established at Beltsville, MD, in 1986 to assess the effect of conventional and no-till cultural practices on the movement of pesticides into shallow groundwater. Groundwater samples taken from unconfined (< 1.5 m deep) and confined (< 3 m deep) monitoring wells in 1986-1988 were analyzed for atrazine [6-chloro-N- ethyl-N'-(1-methylethyl)-1,3,5-triazine-2,4-diamine], deethylatrazine [6-chloro-N-(1-methylethyl)-1, 3,5-triazine-2,4-diamine], alachlor 12- chloro-N-2, 6-diethylphenyl)-N-(methoxymethyl)acetamide], cyanazine [2- [[4-chloro-6-(ethylamino)-1,3,5-triazine-2-yl] amino]-2- methylpropanenitrile], and carbofuran (2,3-dihydro-2,2-dimethyl-7- benzofuranyl methylcarbamate). Atrazine was found in groundwater all year, while cyanazine, alachlor, and carbofuran were present only for a short period (< 3 mo) after pesticide application. Fairly constant background levels of < 0.5 microgram L-1 atrazine were found under fields treated before 1986, while levels under continuously treated fields were < 2.0 microgram L-1 for 22 of 25 samplings. Pesticide residues in unconfined groundwater were usually higher (ca. 2 to 4X) than in confined groundwater. Rainfall timing relative to pesticide application was critically important to pesticide leaching. A prolonged rain immediately after the 1988 application resulted in peak atrazine and cyanazine levels of ca. 200 microgram L-1 in unconfined and ca. 30 to 40 microgram L-1 in confined groundwater, which resulted in short- term levels ca. 2 to 50X greater under no-till than conventional till plots. Results of this study suggest that preferential transport occurred. NAL Call No.: QH540.J6 ***************************************************************** 38. The effect of crop rotation on nitrate leaching losses; sandland and limestone aquifers. Shepherd, M. A.; Johnson, P. A.; Smith, P. Asp-appl-biol p.183-190. (1992). In the series analytic: Nitrate and farming systems / edited by J.R. Archer, K.W.T. Goulding, S.C. Jarvis, C.M. Knott, I. Lord, S.E. Ogilvy, J. Orson, K.A. Smith, and B. Wilson. Descriptors: nitrate-; leaching-; rotations-; crop-husbandry; soil-fertility; cultivation-; cover-crops; aquifers-; limestone-; limestone-soils; sandy-soils; cropping-systems; stubble-cultivation; eastern-england NAL Call No.: QH301.A76 ***************************************************************** 39. Effect of extractable soil surface phosphorus on runoff water quality. Daniel, T. C.; Edwards, D. R.; Sharpley, A. N. Trans-ASAE v.36, p.1079-1085. (1993). Includes references. Descriptors: losses-from-soil; phosphorus-; pollution-; runoff-; water-quality; arkansas- Abstract: Phosphorus (P) additions to surface water from agricultural nonpoint sources are of concern, because P often limits eutrophication of surface waters. Numerous sources of runoff P exist: indigenous soil and plant material, land-applied manure and sludge, and commercial fertilizer. In many soils receiving commercial fertilizer and manure, concentrations of P at the soil surface have been steadily rising due to either long-term or excessive applications of P. Critical levels of soil surface P may exist, above which runoff may promote eutrophication. Methods for rationally identifying these critical levels are needed to manage losses of P, which implies the need for curate methods of relating soil surface P concentration (Ps) to runoff P concentration. A study was conducted on both pasture and tilled plots (with and without residue) to evaluate the relationship between Ps and dissolved reactive P in runoff (PR) using simulated rainfall. The data indicated that even for comparable storms, Ps alone was not a satisfactory estimator of PR. A model describing the kinetics of P release from surface soil to runoff was used to include additional variables in predicting PR. When used with uncalibrated parameters, the model explained a significant proportion of the variation in observed PR values for pasture plots (r2 = 0.43) but was less successful in predicting PR for tilled plots (with and without residue, r2 = 0.13). Calibration of (adjustments to) the extraction coefficients resulted in an overall coefficient of determination between observed and predicted PR values of 0.73. While the model was successful in describing how PR and the independent variables are related for the pasture plots, the extraction coefficients should be calibrated to obtain best estimates of PR. When used with calibrated extraction coefficients, the model provided. NAL Call No.: 290.9-Am32T ***************************************************************** 40. Effect of soil test phosphorus on runoff water quality. Daniel, T. C.; Edwards, D. R.; Sharpley, A. N. Pap-Am-Soc-Agric-Eng. St. Joseph, Mich. : American Society of Agricultural Engineers,. Winter 1991. (91-2605) 13 p. Paper presented at the 1991 International Winter Meeting sponsored by The American Society of Agricultural Engineers, December 17-20, 1991, Chicago, Illinois. Descriptors: soil-; water-quality; phosphorus-; water-pollution; runoff- NAL Call No.: 290.9-Am32P ***************************************************************** 41. Effect of tillage systems on soil erosion and runoff water quality. Seta, A. K. 1. 1991. vii, 68 leaves : ill.. Includes vita and abstract. Descriptors: Soil-erosion; Runoff-; Tillage- NAL Call No.: KyU Thesis-1991-Seta ***************************************************************** 42. Effectiveness of BMPs for stormwater management in urbanized watersheds. Kuo, C. Y.; Virginia Water Resources Research Center. Blacksburg : Virginia Water Resources Research Center, Virginia Polytechnic Institute and State University, 1987. xiii, 121 p. : ill., maps. Partly funded by the U.S. Geological Survey, U.S. Dept. of the Interior. Descriptors: Urban-runoff-Mathematical-models; Water-quality-management-Data- processing NAL Call No.: TD201.V57--no.159 ***************************************************************** 43. The effectiveness of buffer strips for ameliorating offsite transport of sediment, nutrients, and pesticides from silvicultural operations. Comerford, N.; Mansell, R.; Neary, D.; National Council of the Paper Industry for Air and Stream Improvement (U.S.). New York, N.Y. : National Council of the Paper Industry for Air and Stream Improvement, 1992. ii, 48 p. ; 28 cm.. "June 1992.". Descriptors: Forest-management-Environmental-aspects; Forest-influences; Water- Pollution, NAL Call No.: TD899.P3N34-no.631 ***************************************************************** 44. Effectiveness of vegetative buffer strips in reducing herbicide transport with surface runoff under simulated rainfall. Misra, A. K.; Baker, J. L.; Mickelson, S. K.; Shang, H. Pap-Am-Soc-Agric-Eng. St. Joseph, Mich. : American Society of Agricultural Engineers,. Summer 1994. (94-2120/94-2155) 21 p. Paper presented at the 1994 International Summer Meeting, sponsored by the ASAE, June 19-22, 1994, Kansas City, Missouri. Descriptors: grass-strips; water-pollution; water-quality; runoff-water; herbicides-; rainfall-simulators NAL Call No.: 290.9-Am32P ***************************************************************** 45. Effects of agricultural nutrient management on nitrogen fate and transport in Lancaster County, Pennsylvania. Hall, D. W.; Risser, D. W. Water-resour-bull v.29, p.55-76. (1993). Includes references. Descriptors: nitrogen-; nitrates-; application-to-land; movement-in-soil; losses- from-soil; water-budget; precipitation-; groundwater-; manures-; fertilizers-; hydrology-; groundwater-pollution; pennsylvania-; best-management-practices; nonpoint-source-pollution; groundwater- hydrology Abstract: Nitrogen inputs to, and outputs from, a 55-acre site in Lancaster County, Pennsylvania, were estimated to determine the pathways and relative magnitude of loads of nitrogen entering and leaving the site, and to compare the loads of nitrogen before and after the implementation of nutrient management. Inputs of nitrogen to the site were manure fertilizer, commercial fertilizer, nitrogen in precipitation, and nitrogen in ground-water inflow; and these sources averaged 93, 4, 2, and 1 percent of average annual nitrogen additions, respectively. Outputs of nitrogen from the site were nitrogen in harvested crops, loads of nitrogen in surface runoff, volatilization of nitrogen, and loads of nitrogen in ground-water discharge, which averaged 37, less than 1, 25, and 38 percent of average annual nitrogen removals from the site, respectively. Virtually all of the nitrogen leaving the site that was not removed in harvested crops or by volatilization was discharged in the ground water. Applications of manure and fertilizer nitrogen to 47.5 acres of cropped fields decreased about 33 percent, from an average of 22,700 pounds per year (480 pounds per acre per year) before nutrient management to 15,175 pounds of nitrogen per year (320 pounds per acre per year) after the implementation of nutrient management practices. Nitrogen loads in ground-water discharged from the site decreased about 30 percent, from an average of 292 pounds of nitrogen per million gallons of ground water before nutrient management to an average of 203 pounds of nitrogen per million gallons as a result of the decreased manure and commercial fertilizer applications. Reductions in manure and commercial fertilizer applications caused a reduction of approximately 11,000 pounds (3,760 pounds per year; 70. ground water from the 55-acre site during the three-year period 1987- 1990. NAL Call No.: 292.9-Am34 ***************************************************************** 46. Effects of deep tillage on redistribution of lead shot and chufa tuber biomass at Catahoula Lake, Louisiana. Peters, M. S. M. S. 1. 1992. vi, 25 leaves : ill.. Vita. Descriptors: Waterfowl-management-Louisiana; Lead-Toxicology-Louisiana; Tillage- Louisiana; Catahoula-Lake-La NAL Call No.: LU 378.76-L930-1992-pete ***************************************************************** 47. Effects of management practices on surface water quality from rice fields. Feagley, S. E.; Sigua, G. C.; Bengston, R. L.; Bollich, P. K.; Linscombe, S. D. La-Agric-La-Agric-Exp-Stn v.36, p.8-10. (1993). Descriptors: oryza-sativa; water-pollution; weed-control; cultural-control; fertilizers-; field-tests; no-tillage-; cultivation-; water-quality; louisiana- NAL Call No.: 100-L939 ***************************************************************** 48. Effects of poultry litter application on surface water quality. 1. A field experiment. Huhnke, R. L.; Storm, D. E.; Brown, G. O.; Smolen, M. D. Pap-Am-Soc-Agric-Eng. St. Joseph, Mich. : American Society of Agricultural Engineers,. Summer 1992. (92-2121/92-3010) 14 p. Paper presented at the "1992 International Summer Meeting sponsored by the American Society of Agricultural Engineers," June 21-24, 1992, Charlotte, North Carolina. Descriptors: poultry-manure; soil-chemistry; pastures-; runoff-water; tillage-; plant-height; water-quality; water-pollution; waste-utilization; rain-; oklahoma- NAL Call No.: 290.9-Am32P ***************************************************************** 49. The effects of tillage and crop residues on water and nitrate movement in soil columns. Serem, V. K.; Madramootoo, C. A. Pap-Am-Soc-Agric-Eng. St. Joseph, Mich. : American Society of Agricultural Engineers,. Summer 1993. (932082) 16 p. Paper presented at the "1993 International Summer Meeting sponsored by The American Society of Agricultural Engineers, and The Canadian Society of Agricultural Engineering," June 20-23, 1993, Spokane, Washington. Descriptors: tillage-; crop-residues; nitrates-; water-quality; drainage-; leaching- NAL Call No.: 290.9-Am32P ***************************************************************** 50. Effects of tillage on pesticide concentrations in shallow ground water and surface runoff from fragipan soils in North Mississippi, USA. Smith, S. Jr. Proceedings of Industrial and Agricultural Impacts on the Hydrologic Environment the Second USA/CIS Joint Conference on Environmental Hydrology and Hydrogeology / USA/CIS Joint Conference on Environmental Hydrology and Hydrogeology. Alexandria, VA : Water Environment Federation, c1993.. v. 2 p. 79-91. Title on cover : Environmental impact of agricultural practices and agrichemicals / edited by Y. Eckstein and A. Zaporozec. Descriptors: glycine-max; groundwater-pollution; surface-water; runoff-; pesticides-; concentration-; watersheds-; fragipans-; no-tillage-; movement-in-soil; mississippi- NAL Call No.: GB652.U82-1993 ***************************************************************** 51. Estimation of nitrate concentrations in groundwater using a whole farm nitrogen budget. Barry, D. A. J.; Goorahoo, D.; Goss, M. J. J-environ-qual v.22, p.767-775. (1993). Includes references. Descriptors: nitrate-nitrogen; leaching-; nitrogen-balance; farming-systems; rotations-; zea-mays; glycine-max; triticum-aestivum; phleum-pratense; medicago-sativa; groundwater-pollution; farming-systems-research; ontario- Abstract: Contamination of groundwater under agricultural land by NO3 is influenced by the kind of farming system. One possible method of selecting farming systems that result in less NO3 leaching is to calculate whole farm N budgets, that are simplified by assuming soil-N remains constant from one cycle of a rotation to the next. This method was applied to two model crop rotations using average crop yield data for two regions of Ontario, and to a cash-crop farm and a dairy farm using information on purchases, sales, and crop yields, for these farms. The model rotations were corn (Zea mays L.)-soybean [Glycine max (L.) Merr.]-wheat (Triticum aestivum L.) and corn-soybean- wheat-hay (mixture of timothy, Phleum pratense L. and alfalfa, Medicago sativa L.)-hay-hay. Atmospheric deposition (18.4 kg N ha-1 yr) was obtained by literature review. Symbiotic N2 fixation by legume crops with different yields was estimated from regression equations. A net surplus in the N balance was converted to maximum mean NO3-N concentration in groundwater by assuming a groundwater recharge rate of 160 mm yr-1, and no denitrification. Predicted NO3-N concentrations in leachate for the model corn-soybean-wheat rotation were greater for southwestern Ontario (22.4 mg L-1) than western Ontario (8.5 mg L-1), probably because more N fertilizer was recommended in the southwest. Including hay in the model rotation increased the amount of N leached by a factor of two in western Ontario, but only by 9% in the southwest. was 6.7 mg L-1, compared with an average measured value of 9.5 mg L-1 in the tile drainage water. For the dairy farm the predicted value was 58 mg L-1 and a measured value was not available. The simplified N balance method provided useful estimates of potential NO3 leaching losses even though it relied on some major assumptions. A major uncertainty was atmospheric deposition of ammonia volatilized from on- farm sources. Denitrification could be as much as 62 kg N ha-1 yr-1 undr continuous production of grain corn, based on differences between N present after harvest and amount of N leached. NAL Call No.: QH540.J6 ***************************************************************** 52. Evaluating farming strategies for water quality at the Ohio Management Systems Evaluation Area. Watermeier, N. L.; Workman, S. R.; Nokes, S. E.; Borwn, L. C. Proceedings of the National Symposium on Protecting Rural America's Water Resources Partnerships for Pollution Solutions, October 23-26, 1994, Omni Shoreham Hotel, Washington, DC / National Symposium on Protecting Rural America's Water Resources: Partnerships for Pollution Solutions. [Oklahoma, City, OK? : Ground Water Protection Council?, 1994]. p. 185-195. Includes references. Descriptors: zea-mays; glycine-max; triticum-aestivum; continuous-cropping; rotations-; no-tillage-; tillage-; cover-crops; vicia-villosa; nitrate- ; alachlor-; metribuzin-; chlorimuron-; leaching-; groundwater- pollution; water-quality; crop-yield; atrazine-; ohio-; ridge-tillage NAL Call No.: TD927.N38-1994 ***************************************************************** 53. Evaluating herbicide removal by buffer strips under natural rainfall. Arora, K.; Mickelson, S. K.; Baker, J. L.; Tierney, D. P. Pap-Am-Soc-Agric-Eng. St. Joseph, Mich. : American Society of Agricultural Engineers,. Winter 1993. (932593) 16 p. Paper presented at the "1993 International Winter Meeting of the American Society of Agricultural Engineers," December 14-17, 1993, Chicago, Illinois. Descriptors: herbicide-residues; water-quality; erosion-control NAL Call No.: 290.9-Am32P ***************************************************************** 54. Evaluating the effectiveness of forestry best management practices in meeting water quality goals or standards. Dissmeyer, G. E.; United States. Forest Service. Southern Region. Atlanta, Ga. : USDA, Forest Service, Southern Region, [1994] viii, 166 p. : ill.. "July 1994.". Descriptors: Water-quality-United-States; Forest-management-United-States NAL Call No.: 1--Ag84M-no.1520 ***************************************************************** 55. Evaluation of a rice herbicide transport model. Breuer, R. S.; California Environmental Protection Agency. Environmental Hazards Assessment Program. Sacramento, Calif. : Environmental Hazards Assessment Program, State of California, Environmental Protection Agency, Dept. of Pesticide Regulation, Environmental Monitoring and Pest Management Branch, [1992] iv, 7 p. : ill.. Cover title. Descriptors: Herbicides-Environmental-aspects-California-Sacramento-River; Nematocides-Environmental-aspects-California-Sacramento-River; Water- Pollution-California-Sacramento-River-Computer-programs NAL Call No.: TD427.P35B74--1992 ***************************************************************** 56. An evaluation of extension programs to enhance water quality through nutrient management in the urban landscape. Relf, P. D.; McKissack, D. HortTechnology v.2, p.245-247. (1992). Includes references. Descriptors: cooperative-extension-service; volunteers-; environmental- education; educational-programs; water-quality; water-pollution; fertilizers-; runoff-; mass-media; extension-education; technology- transfer; maryland-; nonpoint-source-pollution; chesapeake-bay; master-gardeners NAL Call No.: SB317.5.H68 ***************************************************************** 57. Evaluation of GLEAMS and PRZM for predicting pesticide leaching under field conditions. Zacharias, S.; Heatwole, C. D. Trans-ASAE v.37, p.439-451. (1994). Includes references. Descriptors: zea-mays; no-tillage-; pesticides-; leaching-; simulation-models; virginia-; groundwater-loading; effects-of-agricultural-management-systems; pesticide-rootzone-model; nonpoint-source-pollution Abstract: Pesticide simulation models, GLEAMS and PRZM, were evaluated for their ability to predict pesticide behavior using field data from a plot under no-till corn in the Coastal Plain region of Virginia. The models were evaluated in an uncalibrated mode as well as with adjustment of important hydrology parameters. The evaluation of model performance was based on graphical displays and statistical measures. Difference in evapotranspiration (ET) predictions by the two models caused the simulated results from their hydrology components to vary. Runoff and soil moisture measured in the field were predicted reasonably well after adjusting important hydrology parameters. Except for differences in magnitude, both models predicted the chemical concentration profiles similarly. Overall, GLEAMS represented pesticide behavior in soil better than PRZM. The models, GLEAMS and PRZM, performed well in predicting pesticide mass in the root zone, but were less reliable in predicting pesticide concentration distributions in soil. Model predictions of pesticide fate and transport were not greatly affected by changes in curve number and the water holding capacity of the soil. NAL Call No.: 290.9-Am32T ***************************************************************** 58. Evaluation of two field screening test kits for the detection of PCBs in soil by immunoassay. Waters, L. C.; Smith, R. R.; Stewart, J. H.; Jenkins, R. A.; Counts, R. W. J-AOAC-Int v.77, p.1664-1671. (1994). Includes references. Descriptors: soil-testing; polluted-soils; polychlorinated-biphenyls; contamination-; determination-; screening-; immunoassay- NAL Call No.: S583.A7 ***************************************************************** 59. Fall tillage method: effect on short-term carbon dioxide flux from soil. Reicosky, D. C.; Lindstrom, M. J. Agron-j v.85, p.1237-1248. (1993). Includes references. Descriptors: autumn-; tillage-; techniques-; no-tillage-; carbon-dioxide; flow-; soil-air; global-warming; greenhouse-effect; air-pollution; climatic- change; soil-analysis; organic-compounds; carbon-; soil-water-content; soil-; surface-roughness; surface-roughness; minnesota- Abstract: The increasing concern for rising CO2 concentrations from agricultural activities has prompted the need to better understand the flux of greenhouse gases to the atmosphere. This work determines the effect of four fall tillage methods on short-term CO2 flux from a Hamerly clay loam (fine-loamy, frigid Aeric Calciaquoll) in the northern Corn Belt. Moldboard plow only, moldboard plow plus disk harrow twice, disk harrow once, and chisel plow once using standard tillage equipment following a wheat (Triticum aestivum L.) crop were compared with no-tillage. The CO2 flux was measured with a large portable system commonly used to measure canopy gas exchange of field crops. Measurements of CO2 flux were initiated within 5 min after tillage completion for each tillage treatment and continued intermittently for 19 d. Moldboard plow had the roughest soil surface and the highest initial CO2 flux (29 g m-2 h-1) and maintained the highest flux throughout the study. Moldboard plow plus disking twice and chisel plow had similar initial rates (7 and 6 g m-2 h-1, respectively) that were greater than disk harrow and no-tillage. The high initial CO2 fluxes were more related to depth of soil disturbance that resulted in a rougher surface and larger voids than to residue incorporation. The differences in CO2 flux between tillage treatments were small but consistent 19 d after initial tillage and 64 mm rain. Lower CO2 flux rates caused by tillage were associated with low soil disturbance and/or small voids. Tillage. soil management can minimize agriculture's impact on global CO2 increase. NAL Call No.: 4-AM34P ***************************************************************** 60. Farm nutrient management training needs assessment for Minnesota : a nutrient management technical assistance project. Minnesota. Dept. of Agriculture. [Saint Paul, Minn. : Minnesota Dept. of Agriculture, 1994] 61 p. : 1 map. "Funded by a grant from USEPA, Section 319 of the Water Quality Act of 1987, "Nonpoint source management".". Descriptors: Soil-management-Minnesota; Soil-fertility-Minnesota; Soil-science- Minnesota; Needs-assessment-Minnesota NAL Call No.: S599.M6F37--1994 ***************************************************************** 61. A farm scale water quality planning system for evaluating best management practices. Batchelor, W. D.; Dillaha, T. A. I.; Wolfe, M. L.; Heatwole, C. D.; Mostaghimi, S. Pap-Am-Soc-Agric-Eng. St. Joseph, Mich. : American Society of Agricultural Engineers,. Summer 1994. (94-2156/94-2185) 17 p. Paper presented at the "1994 International Summer Meeting sponsored by the American Society of Agricultural Engineers," June 19-22, 1994, Kansas City, Missouri. Descriptors: water-pollution; water-quality; land-management; simulation-models; pollution-control; non-point-source-pollution NAL Call No.: 290.9-Am32P ***************************************************************** 62. A field study to evaluate leaching of aldicarb, metolachlor, and bromide in a sandy loam soil. Smith, C. N.; Parrish, R. S. J-environ-qual v.22, p.562-577. (1993). Paper presented at the USDA-ARS Beltsville Agricultural Research Center Symposium XVII, "Agricultural Water Quality Priorities, A Team Approach to Conserving Natural Resources," May 4-8, 1992, Beltsville, MD. Descriptors: aldicarb-; granules-; metolachlor-; emulsifiable-concentrates; bromide-; tracers-; leaching-; vertical-movement; application-; spatial- variation; soil-depth; sandy-loam-soils; saturated-conditions; persistence-; half-life; arachis-hypogaea; uptake-; georgia- Abstract: Transport and transformation of pesticides used in agricultural situations are subject to vailability from several sources that are impossible to simulate in laboratory settings. This study was conducted to characterize pesticide leaching behavior under conventional croping conditions and to determine the impacts of related sources of vailability. An agricultural field site (Ardilia fine sandy loam, Clarendon loamy sand, Tifton loamy sand, and Lucy loamy sand) located within the Dougherty Plain region of southwest Georgia was used to study pesticide movement in unsaturated and saturated soil zones from 1984 through 1988. A granular formulation of aldicarb [2-methyl-2 - (methylthio) propionaldehyde O-(methylcarbamoyl) oxime], an emulsifiable concentrate of metolachlor [2-chloro-N-(2-ethyl-6-methyl- phenyl)-N-(2-metboxy-1-methyl ethyl) acetamide], and a bromide (Br-) tracer were applied on peanut (Arachis hypogea L.) crops under modified conventional tillage practices. Postapplication vertical movement was monitored for periods of up to 111 d for pesticides and 1307 d for Br-. Application distributions for aldicarb showed measured coefficients of variation ranging from 42 to 72, and for metolachlor from 23 to 44. Spatial variability analyses indicated the existence of small-scale correlation for both pesticides upon initial application, and some large-scale trending was observed for metolachlor. Field-based transformation rates of aldicarb were up to three times higher than laboratory-based values. There was no evidence of migration of any of the pesticides into the saturated zone during the study, although Br- was observed at less than 1 mg kg(-1) in well-water samples. Aldicarb degraded almost completely within d each year, and. concentrations decreasing with increasing depth, and there was no significant movement below 0.3 m. Bromide was observed in soil samples as deep as 3 m only on the 1307th d, and the profiles showed peak concentrations no lower than 1.5 m with relative verticaldispersion increasing continuously. NAL Call No.: QH540.J6 ***************************************************************** 63. Forest practices as nonpoint sources of pollution in North America. Binkley, D.; Brown, T. C. Water-resour-bull v.29, p.729-740. (1993). Includes references. Descriptors: water-pollution; streams-; water-quality; forest-influences; forest- management; usa-; canada- Abstract: Forest management activities may substantially alter the quality of water draining forests, and are regulated as nonpoint sources of pollution. Important impacts have been documented, in some cases, for undesirable changes in stream temperature and concentrations of dissolved oxygen, nitrate-N, and suspended sediments. We present a comprehensive summary of North American studies that have examined the impacts of forest practices on each of these parameters of water quality. In most cases, retention of forested buffer strips along streams prevents unacceptable increases in stream temperatures. Current practices do not typically involve addition of large quantities of fine organic material to streams, and depletion of streamwater oxygen is not a problem; however, sedimentation of gravel streambeds may reduce oxygen diffusion into spawning beds in some cases. Concentrations of nitrate-N typically increase substantially after forest harvesting and fertilization, but only a few cases have resulted in concentrations approaching the drinking-water standard of 10 mg of nitrate- N/L. Road construction and harvesting increase suspended sediment concentrations in streamwater, with highly variable results among regions in North America. The use of best management practices usually prevents unacceptable increases in sediment concentrations, but exceptionally large responses (especially in relation to intense storms) are not unusual. NAL Call No.: 292.9-Am34 ***************************************************************** 64. Forests as nonpoint sources of pollution, and effectiveness of best management practices. National Council of the Paper Industry for Air and Stream Improvement (U.S.). New York, N.Y. : National Council of the Paper Industry for Air and Stream Improvement, 1994. 2, iii, 57 p. : ill.. Cover title. Descriptors: Nonpoint-source-pollution-United-States; Forest-management- Environmental-aspects-United-States; Watershed-management-Environmental- aspects-United-States NAL Call No.: TD899.P3N34--no.672 ***************************************************************** 65. GLEAMS modeling of BMPs to reduce nitrate leaching in Middle Suwannee River Area. Reck, W. R. Environmentally sound agriculture proceedings of the second conference 20-22 April 1994 /. St. Joseph, Mich. : American Society of Agricultural Engineers, c1994. 1994. 361-367. Includes references. Descriptors: groundwater-; water-quality; nitrate-nitrogen; leaching-; farming- systems; farm-management; dairy-farming; poultry-farming; monitoring-; models-; computer-techniques; florida-; groundwater-loading-effects-of-agricultural-management-systems; best-management-practices NAL Call No.: S589.7.E57-1994 ***************************************************************** 66. GOSSYM/COMAX: a cotton crop management emphasizing irrigation scheduling and water quality. McKinion, J. M.; Boone, M. Y. L.; Porter, D. O.; Whisler, F. D. Proceedings of Industrial and Agricultural Impacts on the Hydrologic Environment the Second USA/CIS Joint Conference on Environmental Hydrology and Hydrogeology / USA/CIS Joint Conference on Environmental Hydrology and Hydrogeology. Alexandria, VA : Water Environment Federation, c1993.. v. 2 p. 23-36. Title on cover : Environmental impact of agricultural practices and agrichemicals / edited by Y. Eckstein and A. Zaporozec. Descriptors: gossypium-; irrigated-farming; irrigation-scheduling; simulation- models; water-quality; mississippi- NAL Call No.: GB652.U82-1993 ***************************************************************** 67. Herbicide leaching under tilled and no-tillage fields. Gish, T. J.; Shirmohammadi, A.; Vyravipillai, R.; Wienhold, B. J. Soil-Sci-Soc-Am-j. [Madison, Wis.] Soil Science Society of America. May/June 1995. v. 59 (3) p. 895-901. Includes references. Descriptors: atrazine-; alachlor-; losses-from-soil; formulations-; persistence- ; adsorption-; degradation-; leaching-; movement-in-soil; no-tillage-; tillage-; drained-conditions; controlled-release; groundwater-; water- quality; maryland-; well-drained-soils Abstract: The effect of no-tillage practices on water quality exiting the root zone of deep, well-drained fields is largely unknown. This project was initiated to determine herbicide leaching characteristics as influenced by tillage practice and herbicide formulation. The research site consisted of four adjacent (0.25-ha) fields, two fields each dedicated to either tilled or no-tillage management. One field in each tillage regime received a controlled-release formulation of atrazine [6- chloro-N-ethyl-N'-(1-methylethyl)-1,3,5-triazine-2,4-diamine] and alachlor [2-chloro-N-(2,6-diethylphenyl)-N-(methoxymethyl)-acetamide, starch encapsulated], while the others received standard herbicide formulations of atrazine and alachlor. Both herbicide formulations were annually applied at the same rate: 1.7 kg ha-1 for atrazine and 2.8 kg ha-1 for alachlor. Atrazine, deethylatrazine [DEAT; 6-chloro-N-(1- methylethyl)-1,3,5-triazine-2,4-diamine], alachlor, and Br-1 concentrations were monitored with 12 suction lysimeters (six each at 1.5- and 1.8-m depths) in each field. Alachlor was detected in <3% of all samples collected, regardless of tillage practice or herbicide formulation, while atrazine was detected in >41% of the samples. Under no-tillage, atrazine was detected in <28% of the samples with <13% exceeding the U.S. Environmental Protection Agency Health Advisor level of 3 micrograms L-1 atrazine. Under tilled conditions, 53% of the samples contained atrazine, with 35% exceeding 3 micrograms L-1 atrazine. Averaged atrazine metabolite concentration of DEAT under no- tillage was 0.52 micrograms L-1 vs. 0.39 micrograms L-1 for tilled fields. Similar Br- transport between tillage practices and reduced atrazine levels. well-drained soils, can have a positive impact on groundwater quality. NAL Call No.: 56.9-So3 ***************************************************************** 68. Impact of BMP's on stream and ground water quality in a USDA demonstration watershed in the eastern Coastal Plain. Stone, K. C.; Hunt, P. G.; Novak, J. M.; Matheny, T. A. Environmentally sound agriculture proceedings of the second conference 20-22 April 1994 / p.280-286. (1994). Includes references. Descriptors: water-quality; evaluation-; streams-; groundwater-; intensive- farming; environmental-impact; watersheds-; north-carolina; best-management-practices NAL Call No.: S589.7.E57-1994 ***************************************************************** 69. The impact of conservation tillage on pesticide runoff into surface Fawcett, R. S.; Christensen, B. R.; Tierney, D. P. J-soil-water-conserv v.49, p.126-135. (1994). Includes references. Descriptors: conservation-tillage; environmental-impact; pesticides-; runoff-; losses-from-soil; surface-water; water-pollution; reviews- NAL Call No.: 56.8-J822 ***************************************************************** 70. Impact of reservoir tillage on runoff quality and quantity. Rochester, E. W.; Hill, D. T.; Yoo, K. H. Trans-ASAE v.37, p.1183-1186. (1994). Includes references. Descriptors: tillage-; puddling-; runoff-; runoff-water; water-quality; soil- compaction; gossypium-hirsutum; organic-nitrogen-compounds; phosphorus- ; nitrate-; ammonium-; alabama- Abstract: The effects of reservoir tillage on runoff and water quality were studied under two levels of soil compaction in the production of cotton. A wide frame tractive vehicle was used during plot establishment and during all farm operations to provide the desired soil compactions. LEPA (Low Energy Precision Application) irrigation was used to apply supplemental water as required. Runoff quantity was monitored with flumes and runoff samples were taken using Coshocton- type runoff samplers. Thirteen runoff events were monitored and analyzed over a two-year period for the replicated, four-treatment study. Reservoir tillage decreased runoff and total discharges of organic nitrogen and phosphate. Differences in concentrations of water quality parameters (total solids, ammonium, total kjeldahl nitrogen, nitrate, phosphate, and COD) were not statistically significant. Although not statistically different, total runoff and total discharge of water quality parameters (except phosphate) were lower for the low compacted treatments compared to the high compacted treatments. NAL Call No.: 290.9-Am32T ***************************************************************** 71. Impact of reservoir tillage on runoff quality and quantity. Rochester, E. W.; Hill, D. T.; Yoo, K. H. Pap-Am-Soc-Agric-Eng. St. Joseph, Mich. : American Society of Agricultural Engineers,. Summer 1993. (93-2114) 16 p. Paper presented at the "1993 International Summer Meeting sponsored by The American Society of Agricultural Engineers and The Canadian Society of Agricultural Engineering," June 20-23, 1993, Spokane, Washington. Descriptors: cotton-; tillage-; runoff-; soil-compaction; water-quality NAL Call No.: 290.9-Am32P ***************************************************************** 72. Impact of tillage on microbial activity and the fate of pesticides in the upper soil. Levanon, D.; Meisinger, J. J.; Codling, E. E.; Starr, J. L. Water-air-soil-pollut v.72, p.179-189. (1994). Includes references. Descriptors: atrazine-; metolachlor-; carbofuran-; diazinon-; insecticide- residues; herbicide-residues; mineralization-; microbial-degradation; plowing-; no-tillage-; biological-activity-in-soil; maryland- NAL Call No.: TD172.W36 ***************************************************************** 73. Impacts of tillage system and chemical incorporation on surface losses of water, soil, atrazine and alachlor. Watermeier, N. L. 1993. xiii, 197 leaves : ill.. Thesis (M.S.)--University of Nebraska--Lincoln, 1993. NBU LD3656-1993-W384 ***************************************************************** 74. Influence of tillage on nitrate loss in surface runoff and tile drainage. Drury, C. F.; McKenney, D. J.; Findlay, W. I.; Gaynor, J. D. Soil-Sci-Soc-Am-j. [Madison, Wis.] Soil Science Society of America. May/June 1993. v. 57 (3) p. 797-802. Includes references. Descriptors: zea-mays; poa-pratensis; conservation-tillage; ridging-; no-tillage- ; tillage-; plowing-; nitrate-; losses-from-soil; runoff-; tile- drainage; runoff-water; drainage-water; water-quality; crop-yield; nitrogen-; nutrient-uptake; water-pollution; conventional-tillage Abstract: A study was conducted to determine the effect of conservation (no- tillage and ridge tillage) and conventional (moldboard plow) tillage systems on NO3(-) loss through surface runoff and tile drainage. Nitrate concentrations and total volume of surface runoff and tile drainage from conventional tillage (CT), no-tillage (NT), and ridge tillage (RT) all planted in continuous corn (Zea mays L.), and Kentucky bluegrass (BG, Poa pratensis L.) treatments, were measured for 3 yr, 1989 to 1991. All corn tillage treatments received a total of 178.6 kg N ha-1 annually during the growing season. The volume of water drained through the tiles in the corn tillage systems always exceeded the volume in surface runoff, typically by factors of 2 to 4. Tile drainage was greatest from the CT treatments, least from BG, and approximately equal from RT and NT treatments in 1989 and 1990. Concentrations of NO3(-) in tile water from CT, RT, and NT treatments exceeded the maximum recommended safe limit for drinking water (10 mg N L-1) in 79% of the leaching events, with flow-weighted concentrations between 12 and 17 mg N L-1 in 1989 and 1990. Flow-weighted NO3(-) concentrations were only 1.2 and 2.6 mg N L-1 from BG in 1989 and 1990, respectively. The total NO3(-) lost in tile water in 1989 was 18, 14, 14, and 1 kg N ha-1 from the CT, RT, NT, and BG treatments, respectively, whereas in 1990 there were 29, 20, 20, and 3 kg N ha-1 lost from the CT, RT, NT, and BG treatments, respectively. Nitrate losses in surface runoff were lower than in tile drainage, with maximums of 2.6 kg N ha-1 for the RT and NT treatments in 1989 and 5.5 kg N ha-1 for the RT treatment in 1990. In 1989 and 1990, both RT and NT treatments had greater yields and N uptake in grain than the CT treatment. A serious drought in 1991 limited corn. NAL Call No.: 56.9-So3 ***************************************************************** 75. An innovative approach to estimate bioavailable phosphorus in agricultural runoff using iron oxide-impregnated paper. Sharpley, A. N. J-environ-qual v.22, p.597-601. (1993). Paper presented at the USDA-ARS Beltsville Agricultural Research Center Symposium XVII, "Agricultural Water Quality Priorities, A Team Approach to Conserving Natural Resources," May 4-8, 1992, Beltsville, MD. Descriptors: runoff-water; phosphorus-; bioavailability-; determination-; methodology-; agriculture- Abstract: The transport of bioavailable phosphorus (BAP) in agricultural runoff can accelerate the eutrophication of receiving water bodies. Bioavailable P is comprised of dissolved P (DP) and bioavailable particulate phosphorus (BPP). Although several algal assays and chemical extractions have been proposed to estimate BAP, procedural and theoretical limitations have restricted their widespread use. This study evaluates the use of Fe oxide-impregnated paper strips (Fe-oxide strips) to estimate the potential BAP content of runoff from 20 agricultural watersheds in the Southern Plains during 1988 to 1990. In the proposed method, BAP and DP are determined by shaking 50 mL of unfiltered or filtered runoff, respectively, with one Fe-oxide strip for 16 h. Phosphorus is removed from the strip by 0.1 M H2SO4 and measured, with BPP calculated as the difference between BAP and DP. Growth of Selnastrum capricornutum was related r2 = 0.63 -0.96) to the BPP content of runoff sediment in 2- to 29-d incubations. Bioavailable PP estimated by the proposed strip method and more widely used NaOH extraction, closely followed a 1:1 relationship. Averaged for all runoff events, strip DP was 90 and 75% of DP determined by standard direct methods, for watersheds with and without tillage, respectively. The lower estimates of strip DP may be partially attributed to a greater transport of acid-hydrolyzable organic and condensed DP in runoff from no-till compared to tilled watersheds. Acting as a P sink, the strip method may have a stronger theoretical basis than chemical extraction in estimating algal-available P in agricultural runoff. In addition, the simplicity of the proposed Fe-oxide strip method will allow BAP estimation with limited resources and may facilitate evaluation of the. receiving waters. NAL Call No.: QH540.J6 ***************************************************************** 76. Integrated pest management and conservation behaviors. Glynn, C. J.; McDonald, D. G.; Tette, J. P. J-soil-water-conserv v.50, p.25-29. (1995). Includes references. Descriptors: alternative-farming; integrated-pest-management; environmental- protection; farmers'-attitudes; environmental-impact; soil- conservation; water-conservation NAL Call No.: 56.8-J822 ***************************************************************** 77. Integrated soil, crop and water management system to abate herbicide and nitrate contamination of the Great Lakes. Tan, C. S.; Drury, C. F.; Gaynor, J. D.; Welacky, T. W. Water-sci-technol v.28, p.497-507. (1993). Paper presented at the IAWQ First International Conference on "Diffuse (Nonpoint) Pollution: Sources, Prevention, Impact, Abatement." September 19-24, 1993, Chicago, Illinois. Descriptors: lakes-; water-pollution; herbicides-; nitrates-; zea-mays; cultivation-; techniques-; cropping-systems; conservation-; conservation-tillage; water-table; management-; ontario- NAL Call No.: TD420.A1P7 ***************************************************************** 78. Integrating water quality modeling with ecological risk assessment for nonpoint source pollution control: a conceptual framework. Chen, Y. D.; McCutcheon, S. C.; Rasmussen, T. C.; Nutter, W. L.; Carsel, R. F. Water-sci-technol v.28, p.431-440. (1993). Paper presented at the IAWQ First International Conference on "Diffuse (Nonpoint) Pollution: Sources, Prevention, Impact, Abatement." September 19-24, 1993, Chicago, Illinois. Descriptors: water-quality; protection-; pollution-control; ecology-; risk-; assessment-; models-; usa-; best-management-practices NAL Call No.: TD420.A1P7 ***************************************************************** 79. Integration of geographic information systems and a computer model to evaluate impacts of agricultural runoff on water quality. He, C.; Riggs, J. F.; Kang, Y. T. Water-resour-bull v.29, p.891-900. (1993). Includes references. Descriptors: runoff-; river-water; water-pollution; water-quality; nitrogen-; phosphorus-; simulation-models; geographical-information-systems; michigan-; geographic-resource-analysis-support-system-grass; grass- waterworks; agricultural-nonpoint-source-pollution-model-agnps; cass- river; saginaw-bay; best-management-practices Abstract: This study integrates an Agricultural Non-Point Source Pollution Model (AGNPS), the Geographic Resource Analysis Support System (GRASS) (U.S. Army Corps of Engineers, 1987), and GRASS WATERWORKS (a hydrologic modeling tool box being developed at the Michigan State University Center for Remote Sensing) to evaluate the impact of agricultural runoff on water quality in the Cass River, a subwatershed of Saginaw Bay. AGNPS is used to estimate the amounts, origin, and distribution of sediment, nitrogen (N), and phosphorus (P) in the watershed. GRASS and GRASS WATERWORKS are used to generate parameters needed for AGNPS from digital maps, which include soil association, land use, watershed boundaries, water features, and digital elevation. Outputs of the model include spatially distributed estimates of volume and peak runoff, overland and channel erosion, sediment yields, and concentrations of nitrogen and phosphorus. Management scenarios are explored in the AGNPS model to minimize sedimentation and nutrient loading. Scenarios evaluated include variations in crop cover, tillage methods, and other agricultural management practices. In addition, areas vulnerable to erosion are identified for best management practices. NAL Call No.: 292.9-Am34 ***************************************************************** 80. Laws and programs for controlling nonpoint source pollution in forest areas. Brown, T. C.; Brown, D.; Binkley, D. Water-resour-bull v.29, p.1-13. (1993). Includes references. Descriptors: water-pollution; water-quality; pollution-control; monitoring- legislation-; programs-; state-government; federal-government; usa-; best-management-practices Abstract: Recent federal legislation strengthened nonpoint source pollution regulations and helped to support and standardize pollution control efforts. A comprehensive review of current state and federal programs for forest areas reveals a substantial increase in agency water quality protection activities. These new efforts emphasize monitoring to assess the use and effectiveness of best management practices (BMPs). Recent monitoring reveals that BMP use is increasing and that such use typically maintains water quality within standards. However, information is generally lacking about the cost effectiveness of BMP programs. Carefully designed and executed monitoring is the key to better specification of BMPs and more cost effective water quality protection. NAL Call No.: 292.9-Am34 ***************************************************************** 81. Leaching of nitrogen and phsophorus from the biomass of three cover crop species. Miller, M. H.; Beauchamp, E. G.; Lauzon, J. D. J-environ-qual v.23, p.267-272. (1994). Includes references. Descriptors: trifolium-pratense; lolium-multiflorum; raphanus-sativus; cover- crops; nitrate-nitrogen; ammonium-nitrogen; phosphorus-; biomass-; leaching-; runoff-water; water-quality; rain-; freezing-; leachates-; drying-; temporal-variation; species-differences; rainfall-intensity Abstract: Cover crops, although they may reduce the leaching of NO3-N to groundwater, may increase nutrient concentration in runoff because of biomass leaching during rainfall events. A simulated rainfall study was conducted in the laboratory to determine the effects of freezing alone and freezing plus drying treatments, loading rate, and rainfall intensity on the leaching of NH4-N, NO3-N, and inorganic P from the biomass of red clover (Trifolium pratense L.), annual ryegrass (Lolium multiflorum L.), and oilseed radish [Raphanus sativus (L.) var. oleifera Dc Metzg]. Concentration of P increased during early stages of leaching, then decreased slowly but remained greater than 50% of the maximum, even after the equivalent of 6.0 cm of simulated rainfall. Concentrations of NO3-N were similar to P but changed less during leaching. Weighted mean concentrations of P ranged from less than 2.0 to more than 15 mg L-1. Concentrations were greatest with oilseed radish and least with red clover. Drying the sample in addition to freezing increased the P concentration, particularly in the initial leaching. About 30% of the biomass P was leached from oilseed radish and annual ryegrass, but only about 20% from red clover. Because oilseed radish had a greater biomass P concentration, the total P leached was much greater than for the other two species. Between 5 and 9% of the biomass N was leached as either NO3-N or NH4-N from ryegrass and red clover while over 10% was leached from oilseed radish. The results indicate that cover crop species differed markedly in their potential impact on nutrient concentration, particularly P, in runoff. Of the three cover crops tested, oilseed radish. NAL Call No.: QH540.J6 ***************************************************************** 82. Livestock manure management and water quality. Wheeler, G.; Miller, A. E. Fact-sheet-Max-C-Fleischmann-Coll-Agric,-Coop-Ext-Serv. [Reno, Nev.] : The College,. 1993. (93-52) 4 p. Includes references. Descriptors: farmyard-manure; waste-disposal; application-to-land; nutrient- availability; nutrient-content; application-rates; chemical-analysis; water-quality; water-pollution NAL Call No.: S544.3.N3C66 ***************************************************************** 83. Long-term effect of tillage and rainfall on herbicide leaching to shallow groundwater. Isensee, A. R.; Sadeghi, A. M. Chemosphere v.30, p.671-685. (1995). Includes references. Descriptors: atrazine-; alachlor-; cyanazine-; herbicide-residues; leaching-; groundwater-pollution; rain-; tillage-; no-tillage-; lateral-movement; groundwater-; silt-loam-soils; maryland-; conventional-tillage; confined-groundwater; unconfined-groundwater NAL Call No.: TD172.C54 ***************************************************************** 84. Managing agricultural phosphorus for protection of surface waters: issues and options. Sharpley, A. N.; Chapra, S. C.; Wedepohl, R.; Sims, J. T.; Daniel, T. C.; Reddy, K. R. J-environ-qual v.23, p.437-451. (1994). Includes references. Descriptors: phosphorus-; pollution-; soil-management; crop-management; losses- from-soil; eutrophication-; runoff-; erosion-; soil-fertility; manures- ; pollution-control; watershed-management; nonpoint-source-pollution Abstract: The accelerated eutrophication of most freshwaters is limited by P inputs. Nonpoint sources of P in agricultural runoff now contribute a greater portion of freshwater inputs, due to easier identification and recent control of point sources. Although P management is an integral part of profitable agrisystems, continued inputs of fertilizer and manure P in excess of crop requirements have led to a build-up of soil P levels, which are of environmental rather than agronomic concern, particularly in areas of intensive crop and livestock production. Thus, the main issues facing the establishment of economically and environmentally sound P management systems are the identification of soil P levels that are of environmental concern; targeting specific controls for different water quality objectives within watersheds; and balancing economic with environmental values. In developing effective options, we have brought together agricultural and limnological expertise to prioritize watershed management practices and remedial strategies to mitigate nonpoint-source impacts of agricultural P. Options include runoff and erosion control and P-source management, based on eutrophic rather than agronomic considerations. Current soil test P methods may screen soils on which the aquatic bioavailability of P should be estimated. Landowner options to more efficiently utilize manure P include basing application rates on soil vulnerability to P loss in runoff, manure analysis, and programs encouraging manure movement to a greater hectareage. Targeting source areas may be achieved by use of indices to rank soil vulnerability to P loss in runoff and lake sensitivity to P inputs. NAL Call No.: QH540.J6 ***************************************************************** 85. Manure and wastewater management systems for open lot dairy operations. Sweeten, J. M.; Wolfe, M. L. Trans-ASAE v.37, p.1145-1154. (1994). Includes references. Descriptors: cattle-manure; dairy-effluent; dairy-wastes; pollution-control; dairy-farming; dairies-; waste-treatment; waste-water-treatment; anaerobic-treatment; texas- Abstract: Dairy industry expansion using open lot designs has impacted water quality and groundwater usage in parts of Central Texas. Field research was conducted at commercial dairy farms in Erath County, Texas, to develop improved design criteria for storage, treatment, and land application systems for open lot dairies. Water use and waste water from milking parlors were monitored along with rainfall runoff from open lots. Water use for milk sanitation and manure removal averaged 148 L per cow per day. Two-stage anaerobic lagoon systems achieved higher solids and nutrient removal efficiencies than a combination of settling basin and one-stage anaerobic lagoons. The two-stage anaerobic lagoon system with 81- to 118-day hydraulic retention time reduced concentrations of volatile solids (VS), chemical oxygen demand (COD), and total kjeldahl nitrogen (TKN) in dairy wastewater from milking parlors by 80 to 82%, 90 to 93% and 55 to 73%, respectively. Solids settling basins reduced VS, COD, and TKN concentrations in wastewater by 35 to 45%, 27 to 47%, and 14 to 24%, respectively. As compared to second-stage lagoon effluent, open lot runoff was higher in K, but similar in TKN and P concentrations and contained a greater proportion affixed solids. Analysis showed that anaerobic lagoon effluent and open lot runoff were good sources of available plant nutrients. NAL Call No.: 290.9-Am32T ***************************************************************** 86. Marginal cost effectiveness analysis for agricultural nonpoint source water quality control. Walker, D. J.; Calkins, B. L.; Hamilton, J. R. J-Soil-Water-Conserv v.48, p.368-372. (1993). In the special edition: The next generation of U.S. agricultural conservation policy. Paper presented at the conference "The Next Generation of U.S. Agricultural Policy", March 14-16, Kansas City, Missouri. Descriptors: water-quality; water-pollution; pollution-control; sediment-; marginal-analysis; cost-effectiveness-analysis; farm-management; furrow- irrigation; return-flow; best-management-practices NAL Call No.: 56.8-J822 ***************************************************************** 87. Metamodels and nonpoint pollution policy in agriculture. Bouzaher, A.; Lakshminarayan, P. G.; Cabe, R.; Carriquiry, A.; Gassman, P. W.; Shogren, J. F. Water-resour-res v.29, p.1579-1587. (1993). Includes references. Descriptors: herbicides-; agricultural-chemicals; groundwater-; surface-water; water-pollution; water-quality; simulation-models; statistical-analysis Abstract: Complex mathematical simulation models are generally used for quantitative measurement of the fate of agricultural chemicals in soil. But it is less efficient to use them directly for regional water quality assessments because of the large number of simulations required to cover the entire region and because the entire set of simulation runs must be repeated for each new policy. To make regional water quality impact assessment on a timely basis, a simplified technique called metamodeling is suggested. A metamodel summarizes the input- output relationships in a complex simulation model designed to mimic actual processes such as groundwater leaching. Metamodels are constructed and validated to predict groundwater and surface water concentrations of major corn and sorghum herbicides in the Corn Belt and Lake States regions of the United States. The usefulness of metamodeling in the evaluation of agricultural nonpoint pollution policies is illustrated using an integrated environmental economic modeling system. For the baseline scenario, we estimate that 1.2% of the regional soils will lead to groundwater detection of atrazine exceeding 0.12 micrograms/L, which compares well with the findings of an Environmental Protection Agency monitoring survey. The results suggest no-till practices could significantly reduce surface water concentration and a water quality policy, such as an atrazine ban, could increase soil erosion despite the conservation compliance provisions. NAL Call No.: 292.8-W295 ***************************************************************** 88. Minimizing nitrate losses from arable soils. Shepherd, M. A.; Davies, D. B.; Johnson, P. A. Soil-use-manage v.9, p.94-99. (1993). Paper presented at the National Agricultural Conference, "Nitrogen management in a changing environment," January 29, 1992, Stoneleigh, Warwickshire. Descriptors: arable-soils; nitrate-; losses-from-soil; leaching-; pollution- control Abstract: Recent experiments on soils overlying sand, chalk and limestone aquifers have shown that nitrate leaching losses can be decreased by modifying crop husbandry. Green cover during winter, if established early enough, can reduce nitrate loss. Cultivations can be timed to minimize leaching, and the advantages of irrigation (increased nitrogen offtake and smaller post-harvest soil mineral nitrogen residues) outweigh the potential disadvantage of increased leaching risk during the growing season. It is important not to over- fertilize crops. Using these techniques within farm rotations has decreased nitrate losses in small plot experiments. The next step is to measure the effects on commercial farms where the scale of operation might preclude the high level of husbandry that is required for successful nitrogen management. NAL Call No.: S590.S68 ***************************************************************** 89. Modeling alternatives to reduce dairy farm and watershed nonpoint source pollution. Sugiharto, T.; McIntosh, T. H.; Uhrig, R. C.; Lardinois, J. J. J-environ-qual v.23, p.18-24. (1994). Technical Reports from the Symposium, "Minimizing Agricultural Nonpoint-Source Impacts", November 2, 1992, Minneapolis, Minnesota. Descriptors: zea-mays; avena-sativa; medicago-sativa; cropping-systems; tillage- ; no-tillage-; anhydrous-ammonia; manures-; simulation-models; sediment- yield; phosphorus-; yields-; watersheds-; dairy-farms; water-pollution; wisconsin- Abstract: Management practices are available that may reduce sediment or phosphorus (P) loading to streams draining agricultural land. An evaluation of the long term effects of implementing one or more of these practices is needed. We used the Erosion Productivity Impact Calculator (EPIC) and Agricultural Non-Point Source (AGNPS) models to evaluate 20 management practices for sediment and P yields from 4 ha fields in a 1272 ha watershed of dairy farms. Five crop sequences [continuous corn (Zea mays L.) CC(OA)AAA, CC(OA)AAAA, CCC(OA)AAA, and CCCAAA; 0, oat (Avena sativa L.); A, alfalfa (medicago sativa L.)] combined with either fall moldboard plowing (mFMP), chisel plow (mFCP), no-till (mNT), or no-till substituting anhydrous ammonia for manure (aNT), were imposed on a toposequence of three Alfisols. The normal sequence, 2 yr of corn, oat/alfalfa seeding, 3 yr of alfalfa with fall application of solid manure followed by moldboard plowing, CC(OA)AAA- mFMP, served as reference. Scenarios were subjected to 42 yr of simulated local climate. Scenarios with 43% or less row crop and mNT on a 4% sloping soil reduced sediment yield from 24 to 47%, at edge of field, but increased total P yield from 158 to 338%, mostly as soluble P. The EPIC output parameters (soil loss ratio [C] for June, erodibility [K], Manning's n, and SCS curve number [CN]) served as inputs to the (AGNPS) model, a cell based single rainfall event model that simulates runoff, sediment, and P yields from a watershed. Crop sequences not exceeding 43% corn and mFCP or aNT reduced watershed sediment yield 13 to 41%, but increased total P yield by 44 to 113% as compared with CC(OA)AAA-mFMP. Average annual costs were $11 ha-1 less. NAL Call No.: QH540.J6 ***************************************************************** 90. A modeling approach to evaluate best management practices. Williams, R. D.; Nicks, A. D. Water-sci-technol v.28, p.675-678. (1993). Paper presented at the IAWQ First International Conference on "Diffuse (Nonpoint) Pollution: Sources, Prevention, Impact, Abatement." September 19-24, 1993, Chicago, Illinois. Descriptors: agricultural-land; crops-; river-water; water-pollution; protection- ; soil-management; water-quality; improvement-; models-; usa-; vegetative-filter-strips NAL Call No.: TD420.A1P7 ***************************************************************** 91. Modeling linked watershed and lake processes for water quality management decisions. Summer, R. M.; Alonso, C. V.; Young, R. A. J-Environ-Qual v.19, p.421-427. (1990). Includes references. Descriptors: watersheds-; lakes-; agricultural-land; simulation-models; water- quality; sediment-; nitrogen-; phosphorus-; chlorophyll-; wetlands-; watershed-management; weather-; trends-; farming-systems; agricultural-nonpoint-source-model-agnps; suspended-sediment; best- management-practices Abstract: A physically based modeling approach is used to link watershed with lake processes and to simulate their responses to land management and weather conditions. Components of the watershed model, AGNPS (agricultural nonpoint-source model), are hydrology, erosion, sediment transport, transport of nitrogen and phosphorus, and chemical oxygen demand. Using a cellular structure, runoff, sediment, and chemical variables from the watershed provide input to a take model. This one- dimensional model of water bodies simulates temperature stratification, mixing by wind, sedimentation, inflow density current, and algal growth. Unsteady advection-diffusion equations characterize the dynamics of suspended sediment, soluble and sediment-attached N and P, and chlorophyll. This model, AGNPS-LAKE, is driven by random generation of weather conditions on a daily basis. Resulting impacts of alternative management plans are simulated by changing agricultural practices and land use, thereby modifying inflow characteristics to a lake. Modeling capabilities are being tested on eutrophic lakes in Minnesota for the purpose of simulating long-term trends and impacts of best management practices. NAL Call No.: QH540.J6 ***************************************************************** 92. Modification of RZWQM for simulating subsurface drainage by adding a tile flow component. Singh, P.; Kanwar, R. S. Trans-ASAE v.38, p.489-498. (1995). Includes references. Descriptors: subsurface-drainage; water-quality; water-flow; rain-; soil- properties; tillage-; simulation-models; computer-simulation; performance-appraisals Abstract: Fluctuating water table and subsurface drain flow components were incorporated in the Root Zone Water Quality Model (RZWQM) to enable the model to simulate subsurface drain flows. Parameters in a modified model were calibrated using observed subsurface drain flows for 1990. Model performance was evaluated by predicting subsurface drain flows for 1991 and 1992 by using the calibrated parameters and comparing the predicted drain flows with observed subsurface drain flows for the same years. The modified RZWQM model, in general, showed a good response to rainfall in terms of time of peak flows. However, the modified RZWQM model overpredicted total tile flows by an average of 13%, and the magnitudes of peak tile flows were generally underpredicted Selected soil properties (bulk density, macroporosity, and residue content) in the surface horizon were changed to investigate tillage effects on tile flows using the modified RZWQM. Four different tillage systems, chisel plow (CP), moldboard plow (MB), no-tillage (NT), and ridge-tillage (RT) , were considered. Predicted tillage effects on subsurface drain flows were consistent with the observed effects (i.e., maximum tile flow for NT and minimum tile flow for MB). NAL Call No.: 290.9-Am32T ***************************************************************** 93. The Moores Creek BMP effectiveness monitoring project. Edwards, D. R.; Daniel, T. C.; Murdoch, J. F.; Vendrell, P. F. Pap-Am-Soc-Agric-Eng. St. Joseph, Mich. : American Society of Agricultural Engineers,. Summer 1993. (932085) 26 p. Paper presented at the "1993 International Summer Meeting sponsored by The American Society of Agricultural Engineers, and The Canadian Society of Agricultural Engineering," June 20-23, 1993, Spokane, Washington. Descriptors: poultry-manure; runoff-water; water-quality; arkansas- NAL Call No.: 290.9-Am32P ***************************************************************** 94. Nitrate contamination of groundwater under irrigated coastal plain soils. Weil, R. R.; Weismiller, R. A.; Turner, R. S. J-Environ-Qual v.19, p.441-448. (1990). Includes references. Descriptors: nitrate-nitrogen; groundwater-; coastal-plain-soils; farmland-; leaching-; poultry-manure; nitrogen-fertilizers; center-pivot- irrigation; precipitation-; soil-depth; phosphates-; ammonium-nitrogen; chloride-; forests-; groundwater-pollution; maryland- Abstract: To develop best management practices (BMP) for agricultural land to protect groundwater, data is needed on the leaching of N from irrigated coastal plain soils treated with Poultry manure. This study was conducted to determine the vertical and seasonal patterns of NO3 leaching under such soils. Four commercially farmed corn (Zea mays L.) fields were studied, two receiving only fertilizer N (240 to 360 kg N ha-1 over a 2-yr period) and two with a continuing history of poultry manure applications (25-29 Mg ha-1 over 2 yr). In each field, a transect of four monitoring wells was installed 4 to 8 m deep (1 m below the seasonally low water table). Three additional wells were installed in forestland adjacent to three of the fields. Groundwater and soils (to 1.5-m depth) were periodically sampled for analysis of NO3(-)N. Under the unmanured field, groundwater concentrations averaged 15.1 mg L-1 during August through November 1986, while the corresponding figure for the manured fields was not significantly different at 18.3 mg L-1. Two months after spreading manure in November and December, as much as 104 mg NO3(-)N was measured in the groundwater under the manured fields. From December 1986 through September 1987 the groundwater under the manured fields had significantly higher NO3(-)N concentrations than did that under the unmanured fields (43.7 vs. 18.1 mg L-1, respectively). Only for one well site with a buried A horizon did high Cl to NO3(-)N ratios and low N)3(-)N concentrations indicate rapid denitrification. The forestland groundwater always contained < 1 mg NO3(-)N L-1, and high Cl to NO3(-)N ratios, suggesting that NO3 in the cropland groundwater was lost after entering the forested areas, and that forests may therefore protect waterways from subsurface N contamination. NAL Call No.: QH540.J6 ***************************************************************** 95. Nitrate leaching in a udic haploboroll as influenced by fertilization and legumes. Campbell, C. A.; Lafond, G. P.; Zentner, R. P.; Jame, Y. W. J-environ-qual v.23, p.195-201. (1994). Includes references. Descriptors: nitrate-nitrogen; leaching-; triticum-aestivum; rotations-; summer- fallow; fertilization-; medicago-sativa; green-manures; soil-water; soil-testing; nitrogen-fertilizers; application-rates; groundwater- pollution; udic-regimes; saskatchewan- Abstract: An ongoing 34-yr crop rotation experiment being conducted on a heavy clay at Indian Head, SK, allowed a snap-shot assessment to he made of the influence of fertilization, legume green manure and legume- grass hay crops, and frequency of cropping to monoculture hard red spring wheat (Triticum aestivum L.) on deep leaching of soil nitrate (NO3). The results showed that NO3 leaching was greatest when summer fallowing was most frequently employed. Although N fertilization may increase NO3-N leached, using a soil test as a guide to choosing fertilizer application rates and cropping annually will minimize NO3 leaching. Further, we found that, although deep-rooted forage crops such as alfalfa (Medicago sativa L.) remove NO3 and water to a depth of 2.4 m, and because legumes increase the N supplying power of the soil, considerable NO3 leaching can still occur under these systems. This is especially true if legume plowdown is followed by a fallow period, because during the fallow period, copious net N mineralization may occur together with increased soil moisture storage. These results do not imply that leaching is pervasive on the Canadian Prairies, but they do confirm certain well-known principles: viz., that NO3 leaching can be expected whenever conditions favor NO3 accumulation and water buildup in soil. Consequently, it is important to keep the land cropped for a large proportion of the time and to use fertilizers at moderate rates based on soil tests. NAL Call No.: QH540.J6 ***************************************************************** 96. Nitrate leaching in dryland agroecosystems as influenced by soil and climate gradients. Evans, S. D.; Peterson, G. A.; Westfall, D. G.; McGee, E. J-environ-qual v.23, p.999-1005. (1994). Includes references. Descriptors: nitrate-nitrogen; leaching-; losses-from-soil; agricultural-soils; evapotranspiration-; soil-water-content; climatic-zones; site-factors; dry-farming; colorado- Abstract: Farmers in dryland agriculture areas of the Central Great Plains have characteristically practiced alternate crop-fallow to stabilize yields. Large amounts of N released soon after sodbreaking and more recent fertilizer additions may have contributed to N movement below crop root zones. Improved water conservation techniques during fallow periods increases the possibility of NO3 leaching below root zones in modern-day crop-fallow systems. Soil topography and water supply may affect leaching potential. This study was conducted to test hypotheses regarding landscape position effects and potential evapotranspiration on depth of water and NO3 penetration. Three sites in eastern Colorado with equal annual precipitation, but with mean potential evapotranspiration varying from 1000 to 1900 mm yr-1 were evaluated. A soil catena was sampled at each site to test landscape effects. All sites were previously managed under tilled wheat-fallow systems for at least 50 yr. All summit (upland) sites had higher water and NO3 contents below their crop root zones than nearby native prairie sites. Soil water and NO3 content of soil profiles to a depth of 9 m were not related to slope position, but there was an inverse relationship between water and NO3 content of soil profiles and potential evapotranspiration. The total NO3-N in cultivated profiles below the normal root zone of crops varied from 126 kg ha-1 at the northern site to 47 kg ha-1 at the southern site. Although some NO3 leaching had occurred, it did not appear to be a major problem for any particular landscape position or climatic zone on cultivated soils. NAL Call No.: QH540.J6 ***************************************************************** 97. Nitrate leaching to a shallow mid-Atlantic Coastal Plain aquifer as influenced by conventional no-till and low-input sustainable grain production systems. Craig, J. P.; Weil, R. R. Water-sci-technol v.28, p.691-700. (1993). Paper presented at the IAWQ First International Conference on "Diffuse (Nonpoint) Pollution: Sources, Prevention, Impact, Abatement." September 19-24, 1993, Chicago, Illinois. Descriptors: nitrates-; leaching-; aquifers-; coastal-plains; groundwater- pollution; pollution-control; cropping-systems; grain-crops; no-tillage- ; sustainability-; maryland- NAL Call No.: TD420.A1P7 ***************************************************************** 98. Nitrous oxide emissions from fertilized soils: summary of available data. Eichner, M. J. J-Environ-Qual v.19, p.272-280. (1990). Literature review. Descriptors: nitrous-oxide; emission-; atmosphere-; fertilizers-; agricultural- soils; environmental-factors; crop-management; soil-types; farming- systems; trends-; global-warming; ozone-depletion; literature-reviews Abstract: Direct measurements of fertilizer-derived N2O emission data from 104 field experiments reported in agriculture and soil science literature that were obtained between 1979 and 1987 were summarized and used to estimate worldwide fertilizer-derived N2O emissions. Although without statistical determination, there appears to be a trend between emissions and type and quantity of fertilizer applied; the available data does not indicate a trend between emissions and a particular soil type or agriculture system. Using the fraction of the N fertilizer evolved as N2O and fertilizer consumption estimates for five fertilizer types, 0.1 to 1.0 Tg N2O-N (avg. 0.3; median 0.2) were estimated to be released during the "sampling period". If these estimates are doubled to account for emissions after the sampling period and emissions from fertilizer lost in drainage water and groundwater, the expected range would be 0.2 to 2.1 Tg N2O-N (avg. 0.7; median 0.5) emitted into the atmosphere in 1984. The magnitude of this estimate is in agreement with recent global estimates. If 100 Tg N fertilizer are consumed worldwide in the year 2000, the global release of fertilizer-derived emissions into the atmosphere will probably not exceed 3 Tg N2O-N in the year 2000. It is estimated that 23 to 315 Gg N2O-N were emitted into the atmosphere from fields of cultivated leguminous crops in 1986. Future research needs were suggested. NAL Call No.: QH540.J6 ***************************************************************** 99. Nonpoint source pollution impacts of alternative agricultural management practice in Illinois: a simulation study. Phillips, D. L.; Hardin, P. D.; Benson, V. W.; Baglio, J. V. J-soil-water-conserv v.48, p.449-457. (1993). Includes references. Descriptors: erosion-; carbon-; nutrient-balance; rotations-; water-pollution; no-tillage-; alternative-farming; innovation-adoption; simulation- models; zea-mays; glycine-max; crop-yield; nitrogen-; phosphorus-; runoff-; illinois-; erosion-productivity-impact-calculator-epic-simulation-model; soil- carbon; nutrient-exports NAL Call No.: 56.8-J822 ***************************************************************** 100. Nutrient and water management practices for sustainable vegetable production in the Lake Apopka Basin. Neal, C. A.; Hanlon, E. A.; White, J. M.; Cox, S.; Ferrer, A. Environmentally sound agriculture proceedings of the second conference 20-22 April 1994 / p.276-279. (1994). Includes references. Descriptors: vegetable-growing; histosols-; management-; water-management; phosphorus-; losses-from-soil; sustainability-; projects-; water- quality; environmental-impact; florida-; nutrient-management NAL Call No.: S589.7.E57-1994 ***************************************************************** 101. Nutrient concentrations in southern United States shallow ground water and surface runoff. Schreiber, J. D. Proceedings of Industrial and Agricultural Impacts on the Hydrologic Environment the Second USA/CIS Joint Conference on Environmental Hydrology and Hydrogeology / USA/CIS Joint Conference on Environmental Hydrology and Hydrogeology. Alexandria, VA : Water Environment Federation, c1993.. p. 131-143. Title on cover : Environmental impact of agricultural practices and agrichemicals / edited by Y. Eckstein and A. Zaporozec. Descriptors: glycine-max; triticum-aestivum; winter-; wheat-; no-tillage-; minimum-tillage; watersheds-; groundwater-pollution; surface-water; runoff-; nutrient-content; groundwater-level; fragipans-; fertilizers-; application-methods; loess-soils; nutrients-; losses-; mississippi- NAL Call No.: GB652.U82-1993 ***************************************************************** 102. Performance of on-site domestic wastewater renovation systems specified for sites with shallow soils. Mote, C. R.; Buchanan, J. R.; Ammons, J. T. Appl-eng-agric v.11, p.437-447. (1995). Includes references. Descriptors: waste-water; waste-water-treatment; soil-depth; seepage-; macropore- flow; tillage-; literature-reviews; water-quality; usa-; seepage-beds Abstract: Observation of two on-site domestic wastewater renovation systems indicate that a soil as shallow as 45 cm (18 in.) has considerable potential for renovating septic tank effluent. However, system design determines, to a great extent, the degree of renovation that occurs. Important design features identified are wider seepage beds (or lower seepage bed loading rates) than are currently specified by some established design procedures, and a tilled soil layer beneath seepage- bed aggregate. Wider seepage beds disperse water more completely throughout a soil profile and promote more micro-pore flow. Thorough tillage of soil beneath seepage beds disrupts macro pore continuity and pro notes more flow in micro pores where the resulting extended soil/wastewater contact promotes renovation. NAL Call No.: S671.A66 ***************************************************************** 103. Pesticide contamination of groundwater in Virginia: BMP impact assessment. Mostaghimi, S.; McClellan, P. W.; Cooke, R. A. Water-sci-technol v.28, p.379-387. (1993). Paper presented at the IAWQ First International Conference on "Diffuse (Nonpoint) Pollution: Sources, Prevention, Impact, Abatement." September 19-24, 1993, Chicago, Illinois. Descriptors: groundwater-pollution; pesticides-; water-quality; improvement-; watersheds-; monitoring-; systems-; agronomy-; techniques-; wells-; virginia-; best-management-practices NAL Call No.: TD420.A1P7 ***************************************************************** 104. Precision nutrient management--impact on the environment and needs for the future. Swader, F.; Woodward, M. Commun-soil-sci-plant-anal. New York, N.Y. : Marcel Dekker. 1994. v. 25 (7/8) p. 881-888. Paper presented at the 1993 International Symposium on Soil Testing and Plant Analysis: Precision Nutrient Management, August 14-19, 1993, Olympia, Washington. Part 1. Descriptors: water-quality; water-pollution; point-sources; pollution-control; nutrients-; management-; application-to-land; environmental-protection; profitability-; trends-; regulations-; trends-; sustainability-; usa-; nutrient-loading; nonpoint-source-pollution NAL Call No.: S590.C63 ***************************************************************** 105. Preliminary evaluation of effects of best management practices in the Black Earth Creek, Wisconsin, priority watershed. Walker, J. F.; Graczyk, D. J. Water-sci-technol v.28, p.539-548. (1993). Paper presented at the IAWQ First International Conference on "Diffuse (Nonpoint) Pollution: Sources, Prevention, Impact, Abatement." September 19-24, 1993, Chicago, Illinois. Descriptors: watersheds-; water-quality; surface-water; water-pollution; agricultural-land; runoff-; erosion-control; soil-management; wisconsin- NAL Call No.: TD420.A1P7 ***************************************************************** 106. Procedures for assessing the effectiveness of best management practices in protecting water and stream quality associated with managed forests. National Council of the Paper Industry for Air and Stream Improvement (U.S.). New York, N.Y. : National Council of the Paper Industry for Air and Stream Improvement, [1988] 1 v. (various pagings) : ill., map. Cover title. Descriptors: Forest-management; Water-quality NAL Call No.: TD899.P3N34-no.538 ***************************************************************** 107. Profits and nitrate leaching under irrigated corn: a simulation. Miller, G. D.; Hanks, R. J.; Andersen, J. C.; Erkison, G. R. Irrig-sci. Berlin, W. Ger. : Springer International. 1993. v. 13 (4) . Includes references. Descriptors: zea-mays; irrigated-stands; nitrate-; leaching-; pollution-control; economic-impact; profits-; simulation- Abstract: The economic impact of reducing the amount of nitrate leached out of the root zone under irrigation in the arid West was examined. The economic incentives of irrigation management were evaluated under the assumptions of both profit-maximizing and utility-maximizing (in reducing cost and effort expended in irrigation) decision-making criteria. The results indicate that there is a coincidence of interests of the farmer and the environment provided some leaching occurred. If no leaching is allowed, profit decreases markedly. Both behaviors result in less nitrate leaching than less profitable or less utility producing irrigating practices. NAL Call No.: S612.I756 ***************************************************************** 108. Reducing soil erosion and agricultural chemical losses with conservation tillage. Seta, A. K.; Blevins, R. L.; Frye, W. W.; Barfield, B. J. J-environ-qual v.22, p.661-665. (1993). Includes references. Descriptors: conservation-tillage; chiselling-; no-tillage-; runoff-water; losses-from-soil; water-quality; nitrate-nitrogen; ammonium-nitrogen; phosphates-; atrazine-; kentucky- Abstract: As nonpoint source pollution of water becomes more evident, more concern is being focused on the effects of agricultural practices on water quality. This study evaluated the effects of conventional tillage (CT), chisel-plow tillage (CP), and no tillage (NT) on the quality of runoff water from a Maury silt loam soil (fine, mixed, mesic Typic Paleudalf) near Lexington, KY. The mean runoff rate, total runoff volume, mean sediment concentration, and total soil losses were significantly less for NT than for CP and CT. Concentration of NO3-, NH4+, and PO4(3-) in the runoff water from NT were greater than from CP or CT. Concentration of atrazine [6-chloro-N-ethyl-N'-(1- methylethyl)-1,3, 5-triazine-2,4-diamine] in the runoff water tended to be higher from CP than from NT or CT. Total losses of NO3-, NH4+, PO4(3-), and atrazine in runoff water were generally in the order CT > CP > NT. The sum of all chemicals lost was less than 3% of the total amount of each applied. NAL Call No.: QH540.J6 ***************************************************************** 109. Relationship between salinity and efficient water use. Letey, J. Irrig-sci. Berlin, W. Ger. : Springer International. 1993. v. 14 (2) . Paper presented at the First Volcani International Symposium on The Limits of Water Use Efficiency in Agriculture, October 1992, Bet Dagan, Israel. Descriptors: salinity-; saline-water; water-use-efficiency; irrigation-water; water-management Abstract: The relationship between salinity and water use efficiency is highly dependent upon which definition of water use efficiency is used. The two common definitions, yield per unit evapotranspiration and yield per unit applied water, both have significant deficiencies and can lead to erroneous conclusions. Thus, the analysis of efficient use of saline waters invokes a broader analysis than merely computing water use efficiency. An array of models is available to simulate the effects of various irrigation management strategies with saline waters. Based on results computed from these models, which consider the osmotic and matric potential effects on plant growth, strategies can be developed to effectively use saline waters in crop production. The cyclic strategy of using waters of different salinities can effectively be used in maintaining crop rotations which include both salt- sensitive and salt-tolerant crops. The major deficiency of the models is that they do not account for the effects of water quality on soil physical conditions with consequent effects on crop production. Indeed, the most limiting factor in use of saline waters on soils may be deterioration of soil physical conditions. The deterioration of soil waters per se but from subsequent rainfall or low salinity waters. Thus far the emphasis on using saline waters on crop production has centered on yields and less attention has been given to the long-term consequences on soil. be a focus of attention in future experiments. Relatively high saline water tables can be maintained without drainage if a non-saline source of water is available, and irrigation amounts can be controlled. This strategy might invoke the necessity for shifting irrigation systems from surface to pressurized systems. Eventually, some salt must be removed from the system. It is probably more efficient to allow it to become very concentrated and remove small volumes to be disposed of in some manner rather than apply it to prodctive land. NAL Call No.: S612.I756 ***************************************************************** 110. Relationship between soil test methods and uptake of copper and zinc by grasses on polluted soils. Singh, R. S.; Singh, R. P.; Rai, R. K.; Agrawal, H. P. Commun-soil-sci-plant-anal. New York, N.Y. : Marcel Dekker. 1994. v. 25 (9/10) p. 1313-1320. Paper presented at the 1993 International Symposium on Soil Testing and Plant Analysis: Precision Nutrient Management. II., August 14-19, 1993, Olympia, Washington. Descriptors: cynodon-dactylon; cyperus-rotundus; polluted-soils; copper-; zinc-; nutrient-uptake; correlation-; soil-testing; nutrient-availability; extractants-; comparisons- NAL Call No.: S590.C63 ***************************************************************** 111. Residual soil nitrate under intensive agriculture. Hofman, G.; Smet, J. de.; Meirvenne, M. v.; Verstegen, P. Commun-soil-sci-plant-anal. New York, N.Y. : Marcel Dekker. 1994. v. 25 (9/10) p. 1197-1207. Paper presented at the 1993 International Symposium on Soil Testing and Plant Analysis: Precision Nutrient Management. II., August 14-19, 1993, Olympia, Washington. Descriptors: agricultural-soils; intensive-farming; nitrate-; nitrogen-content; residues-; regional-surveys; water-pollution; risk-; belgium-; residual-nitrate-content NAL Call No.: S590.C63 ***************************************************************** 112. Residue management for winter wheat and grain sorghum production with limited irrigation. Unger, P. W. Soil-Sci-Soc-Am-j. [Madison, Wis.] Soil Science Society of America. Mar/Apr 1994. v. 58 (2) p. 537-542. Includes references. Descriptors: triticum-aestivum; winter-wheat; sorghum-bicolor; rotations-; irrigated-conditions; crop-residues; management-; conservation-tillage; soil-water-content; soil-water-retention; water-use; crop-yield; yield- components; water-use-efficiency; water-conservation; crop-residue-management Abstract: Winter wheat (Triticum aestivum L.) and grain sorghum [Sorghum bicolor (L.) Moench] are extensively grown in the southern Great Plains on dryland and with irrigation, but yields often are low on dryland and irrigation water is limited. Because both crops respond well to timely irrigation, they sometimes are grown with limited irrigation. Thus, it was hypothesized that using limited irrigation for these crops would produce sufficient residues to increase soil water storage if conservation tillage practices were used. This study on Pullman soil (fine, mixed, thermic Torrertic Paleustoll) at Bushland, TX, determined the effects of residue management on soil water storage and use, yields, and yield components for wheat and sorghum grown in rotation with limited irrigation. Treatments were no-tillage with standing (T1) or shredded (T2) residues, and no-tillage after wheat and tillage after sorghum (T3). Tillage did not affect water storage after wheat, but storage ranged from 68 mm to T3 to 101 mm with T1 after sorghum. Water use by wheat ranged from 93 mm with T3 to 131 mm with T1, but tillage did not affect water use by sorghum. Tillage did not affect wheat yields because differences in soil water storage and use were small and irrigations minimized the water content differences. Tillage did not affect sorghum yields because using no-tillage during fallow after wheat resulted in similar water storage in all cases. This study showed that practices that retain surface residues are effective for producing wheat and grain sorghum in rotation under limited-irrigation conditions in the southern Great Plains. NAL Call No.: 56.9-So3 ***************************************************************** 113. Residue management impact on the environment. Sims, G. K.; Buhler, D. D.; Turco, R. F. Managing agricultural residues /. Boca Raton : Lewis Publishers, c1994.. p. 77-98. Includes references. Descriptors: crop-residues; crop-management; conservation-tillage; tillage-; no- tillage-; transport-processes; losses-from-soil; runoff-; pesticides-; fertilizers-; nutrients-; leaching-; soil-properties; water-quality; surface-water; water-pollution; conventional-tillage NAL Call No.: S604.M28-1994 ***************************************************************** 114. Reversing yield declines of a sub-tropical vertisol. Bell, M. A.; Lafitte, H. R.; Edmeades, G. O.; Chapman, S. C. Commun-soil-sci-plant-anal v.26, p.1105-1119. (1995). Includes references. Descriptors: zea-mays; vertisols-; crop-yield; soil-fertility; soil-degradation; soil-structure; soil-water-content; drainage-; calcium-; bicarbonates-; iron-; chlorosis-; irrigation-water; water-quality; cover-crops; rotations-; land-improvement; mexico- Abstract: Problems of declining yield and increased chlorosis have been noted for maize (Zea mays) grown at CIMMYT's experiment station at Tlaltizapan, Mexico. Yields predicted by a crop model based on temperature and incident radiation showed no decline with time, suggesting that the problem was related to soil factors and/or management. Neither soil organic matter (SOM) nor pH were implicated, as SOM increased by 58%, and soil pH remained unchanged over the 15 years studied. Through a procedure of spatial and temporal analysis, the problem was hypothesized to be a combination of bicarbonate ion (HCO3(-)) induced iron (Fe) chlorosis and soil structure deterioration. Given this hypothesis, a trial was established to evaluate the effect of different cover crops on soil moisture and the subsequent yield of maize. In addition, blocks were sown to alfalfa (Medicago sativa) with the intention that drying of the soil profile would re-establish soil structure. Yield results from the cover crop trial, plus improvements in infiltration and growth in blocks sown to alfalfa, supported the conclusion that changes in management could, at least partially, ameliorate the degradation of soil structure on this station. NAL Call No.: S590.C63 ***************************************************************** 115. Ridge height and furrow blocking effects on water use and grain yield. Unger, P. W. Soil-Sci-Soc-Am-J v. 56, p.1609-1614. (1992). Includes references. Descriptors: triticum-aestivum; sorghum-bicolor; rotations-; water-conservation; water-use; ridges-; height-; furrows-; dams-; no-tillage-; conservation- tillage; soil-water-content; crop-yield; texas-; reduce-tillage Abstract: Because water supplies are limited for crops in the Great Plains, use of water-conserving practices is important. This study determined the influence of ridge height and furrow blocking on water conservation and use, and yields of irrigated winter wheat (Triticum aestivum L.) and dryland grain sorghum [Sorghum bicolor (L.) Moench] grown in rotation. The rotation results in two crops in 3 yr with a 330-d fallow between each crop. The study was conducted from 1981 to 1990 at Bushland, TX, on Pullman clay loam (fine, mixed, thermic Torrertic Paleustoll), Ridge heights were 12 to 15 or 5 to 8 cm and furrows were blocked or open. The ridge-height and furrow-blocking treatments were imposed every 3 yr before planting wheat. No-tillage was used during fallow after wheat and reduced tillage was used to reform the ridges during fallow after sorghum. Water infiltration was little affected by treatments. Differences in soil water content at planting and harvest wert significant in some cases, but trends were inconsistent. Total water use was not affected by ridge height, but was greater with open than with blocked furrows for wheat. Although significant in some years, mean wheat and sorghum yield differences were small. On gentle (< 0.5%) slopes, furrow blocking in combination with no-tillage and reduced tillage did not increase soil water storage or crop yields over those obtained with no-tillage alone. There was no indication that long- term no-tillage and reduced-tillage practices adversely affect wheat and grain sorghum production. NAL Call No.: 56.9-SO3 ***************************************************************** 116. Role of information in the adoption of best management practices for water quality improvement. Feather, P. M.; Amacher, G. S. Agric-econ v. 11, p.159-170. (1994). Includes references. Descriptors: water-quality; information-; incentives-; farm-management; innovation-adoption; profitability-; demonstration-farms; federal- programs; usda-; mathematical-models; usa-; demonstration-projects Abstract: This study investigates the role of information in influencing the adoption of improved farm management practices. A lack of producer information regarding both the profitability and the environmental benefits of adopting improved practices may be a reason why widespread adoption of these practices has not occurred. Compared to direct regulation or financial incentives, raising producer information levels may be a more cost-effective method of increasing adoption. The United States Department of Agriculture has recently established and begun implementing a program based on this idea. To test the validity of the program, a two-stage adoption model is specified and estimated using data from a survey of producers in the program area. The results indicate that producer perceptions play an important role in the decision to adopt. Changing these perceptions by means of an educational program may be a reasonable alternative to financial incentives in encouraging BMP adoption. NAL Call No.: HD1401.A47 ***************************************************************** 117. Simulating NO3-N transport to subsurface drain flows as affected by tillage under continuous corn using modified RZWQM. Singh, P.; Kanwar, R. S. Trans-ASAE v.38, p.499-506. (1995). Includes references. Descriptors: subsurface-drainage; water-flow; water-quality; nitrate-nitrogen; tillage-; simulation-models; computer-simulation; performance- appraisals Abstract: The Root Zone Water Quality Model (RZWQM) was previously modified to simulate subsurface drain flows and evaluate the impact of different tillage systems on subsurface drain flows (Singh and Kanwar, 1994). This article discusses further modifications made in the RZWQM to simulate nitrate-nitrogen (NO3-N) concentrations and N03-N losses with subsurface drain flows. Daily NO3-N concentrations were simulated in subsurface drain flows under four different tillage systems: chisel plow (CP), moldboard plow (MB), no-tillage (NT), and ridge-nllage (RT) by using the modified RZWQM. Simulations were conducted for the growing seasons of three years (1990 to 1992). Simulated N03-N concentrations and losses with subsurface drain flows were compared with the measured data obtained from a water quality research site at Nashua, Iowa. Predicted NO3-N concentrations generally followed the same pattern as the observed concentrations. Simulated annual average NO3-N concentrations in subsurface drain flows were within 11% (averaged over all three years) of observed annual average NO3-N concentrations in subsurface drain flows. The model correctly predicted maximum concentrations under MB treatment and minimum under NT for all three years. Simulated annual NO3-N losses were within 14% (averaged over all three years) of observed annual NO3-N losses. Various N03-N transformation processes need to be calibrated as a function of tillage system to improve model performance. NAL Call No.: 290.9-Am32T ***************************************************************** 118. Simulating tillage effects on water quality by using RZWQM. Singh, P.; Kanwar, R. S. Pap-Am-Soc-Agric-Eng. St. Joseph, Mich. : American Society of Agricultural Engineers,. Winter 1992. (922539) 11 p. Paper presented at the "1992 International Winter Meeting sponsored by the American Society of Agricultural Engineers," December 15-18, 1992, Nashville, Tennessee. Descriptors: water-quality; tillage-; drainage-water; models-; pesticides-; nitrogen-; soil-water-movement; prediction-; iowa- NAL Call No.: 290.9-Am32P ***************************************************************** 119. Simulation and evaluation of alternative nutrient management practices on a demonstration watershed. Stone, K. C.; Hunt, P. G.; Coffey, S. W. Pap-Am-Soc-Agric-Eng. St. Joseph, Mich. : American Society of Agricultural Engineers,. Winter 1993. (93-2572) 13 p. Paper presented at the "1993 International Winter Meeting sponsored by the American Society of Agricultural Engineers," December 14-17, Chicago, Illinois. Descriptors: surface-water; groundwater-; plant-nutrition; watersheds-; catchment-hydrology; water-quality; simulation-models; evaluation-; crop-management; north-carolina; gleams-simulation-model NAL Call No.: 290.9-Am32P ***************************************************************** 120. Sludge application effects on runoff, infiltration, and water quality. Bruggeman, A. C.; Mostaghimi, S. Water-resour-bull v.29, p.15-26. (1993). Includes references. Descriptors: agricultural-soils; sewage-sludge; application-rates; no-tillage-; tillage-; infiltration-; runoff-; losses-from-soil; water-quality; virginia-; conventional-tillage Abstract: Land application of sewage sludge requires careful monitoring because of its potential for contamination of surface water and ground water. A rainfall simulator was used to investigate the effects of freshly applied sludge on infiltration, and on runoff of sediment and nutrients from agricultural crop lands. Rain was applied to 16 experimental field plots. A three-run sequence was used to simulate different initial moisture conditions. Runoff, sediment, and nutrient losses were monitored at the base of each plot during the simulated rainfall events. Sludge was surface applied and incorporated at conventionally-tilled plots and surface applied at no-till plots, at rates of 0, 76, 150 kg-N/ha. Steady-state infiltrability increased as a result of sludge application, although the no-till practice was more effective in increasing the infiltrability than the sludge application. No-till practices greatly reduced runoff, sediment, and nutrient losses from the sludge treated plots, relative to the conventional tillage practices. Incorporation of the sludge was effective in reducing nutrient yields at the conventionally-tilled plots. This effect was more pronounced during the third rainstorm, with wet initial conditions. Peak loadings of nutrients appeared during the rainstorm with wet initial conditions. NAL Call No.: 292.9-Am34 ***************************************************************** 121. Soil nitrate leaching potential indices: using a simulation model as a screening system. Khakural, B. R.; Robert, P. C. J-environ-qual v.22, p.839-845. (1993). Includes references. Descriptors: nitrate-nitrogen; leaching-; losses-from-soil; simulation-models; groundwater-pollution; minnesota- Abstract: Simulation models LEACHM-N (Leaching Estimation and Chemistry Model) first tested using NO3 leaching data obtained from lysimeter and tile drainage studies conducted at three University of Minnesota experiment stations. Both simulation models did well in simulating total (seasonally accumulated) leaching loss of NO3-N from the soil profile. LEACHM-N was selected as a screening took to develop soil NO3 leaching potential (NLP) ratings using soil survey information and representative county weather station data. Simulated growing season total NO3-N leached from the soil profile (below 1.5 m) were used as NLP index. Crop management practices and initial N were kept constant. Soil NO3 leaching potential ratings for three Minnesota counties, Redwood, Stearns, and Sherburne were developed using this method. This soil NLP rating information was included in the Soil Survey Information used to plan best N management schemes. NAL Call No.: QH540.J6 ***************************************************************** 122. Soil, plant, animal waste & water analysis status report for the United States 1988-1991. Plank, C. O.; Council on Soil Testing and Plant Analysis. [Washington, D.C.?] : U.S. Dept. of Agriculture, Extension Service . "Compilation of the tables and writing of the report was done by C. Owen Plank"--P. 2. supported by the United States Department of Agriculture, Extension Service. Descriptors: Soils-United-States-States-Analysis-Statistics; Plants-United- States-States-Analysis-Statistics; Animal-waste-United-States-States- Analysis-Statistics; Water-United-States-States-Analysis-Statistics NAL Call No.: aS593.P53--1992 ***************************************************************** 123. Soil tillage effects on ammonia volatilization from surface-applied or injected animal slurry. Sommer, S. G.; Ersboll, A. K. J-environ-qual v.23, p.493-498. (1994). Includes references. Descriptors: ammonia-; losses-from-soil; volatilization-; cattle-slurry; pig- slurry; harrowing-; air-temperature; wind-speed; soil-water-content; soil-water-potential; mathematical-models Abstract: Ammonia (NH3) losses from cattle (Bos sp.) and pig (Sus scrofa) slurry applied to a harrowed and unworked soil were studied in seven field experiments from October 1990 to December 1991. In one experiment slurry was directly injected into the soil and in six experiments slurry was surface-applied. Ammonia losses mere measured with a wind tunnel system. From directly injected slurry applied to a recently harrowed soil, NH3 losses were 30% of the losses from an unworked soil. Harrowing the soil immediately before surface application of the slurry reduced losses to less than 50% of the losses from an unworked soil. The accumulated NH3 loss from slurry applied in the field was described with a Michaelis-Menten-like equation, showing the NH3 loss reaction modeled adequately as a first-order reaction. The effect of treatment, soil conditions, or environmental conditions on NH3 loss pattern from slurry applied in the field may therefore be treated statistically by comparing the parameters in the Michaelis-Menten equation. NAL Call No.: QH540.J6 ***************************************************************** 124. Statistical techniques for assessing water-quality effects of BMPs. Walker, J. F. J-irrig-drain-eng v.120, p.334-347. (1994). Includes references. Descriptors: farm-management; watersheds-; water-quality; trends-; statistical- analysis; illinois-; best-management-practices NAL Call No.: 290.9-AM3Ps-IR ***************************************************************** 125. Subsurface drip irrigation, A BMP for controlling drainage outflow and reducing groundwater contamination. Phene, C. J.; Hutmacher, R. B.; Ayers, J. E.; Ben Asher, J. Proceedings of Industrial and Agricultural Impacts on the Hydrologic Environment the Second USA/CIS Joint Conference on Environmental Hydrology and Hydrogeology / USA/CIS Joint Conference on Environmental Hydrology and Hydrogeology. Alexandria, VA : Water Environment Federation, c1993.. v. 2 p. 51-69. Title on cover : Environmental impact of agricultural practices and agrichemicals / edited by Y. Eckstein and A. Zaporozec. Descriptors: vegetables-; trickle-irrigation; subsurface-irrigation; drainage-; groundwater-; groundwater-pollution; water-; salinity-; california-; best-management-practice; drainage-outflow-control; groundwater- salinity-control NAL Call No.: GB652.U82-1993 ***************************************************************** 126. Technical guidance for implementing BMPS in the Coastal zone. Frederick, R. E.; Dressing, S. A. Water-sci-technol v.28, p.129-135. (1993). Paper presented at the IAWQ First International Conference on "Diffuse (Nonpoint) Pollution: Sources, Prevention, Impact, Abatement." September 19-24, 1993, Chicago, Illinois. Descriptors: water-pollution; coastal-areas; technical-aid; guidelines-; pollution-; sources-; usa-; best-management-practices; environmental-protection-agency; nonpoint-source-pollution NAL Call No.: TD420.A1P7 ***************************************************************** 127. A test of procedures for determining the ground water protection list. Johnson, B. R.; California Environmental Protection Agency. Environmental Hazards Assessment Program. Sacramento, Calif. : Environmental Hazards Assessment Program, State of California, Environmental Protection Agency, Dept. of Pesticide Regulation, Environmental Monitoring and Pest Management Branch, [1992] v, 42 p. : map. "August, 1992"--Cover. Descriptors: Groundwater-California-Sampling; Groundwater-Pollution-California; Water-quality-California-Measurement; Wells-California NAL Call No.: GB1001.72.S3T469--1992 ***************************************************************** 128. A test of procedures for determining the ground water protection list : appendix to report EH 92-06. Johnson, B. R.; California Environmental Protection Agency. Environmental Hazards Assessment Program. Sacramento, Calif. : Environmental Hazards Assessment Program, State of California, Environmental Protection Agency, Dept. of Pesticide Regulation, Environmental Monitoring and Pest Management Branch, [1992] 126 p. : ill.. Cover title. Descriptors: Groundwater-California-Sampling; Groundwater-Pollution-California; Water-quality-California-Measurement; Wells-California NAL Call No.: GB1001.72.S3T47--1992 ***************************************************************** 129. Tillage and ammonia banding impacts on water, N, and herbicide movement : final technical report. Clay, S. A.; Clay, D. E.; Geological Survey (U.S.). Brookings, S.D. : Plant Science Dept., South Dakota State University, [1993] vii, 49 leaves : ill.. Cover title. Descriptors: Agricultural-chemicals-Environmental-aspects; Groundwater-flow; Tillage-Environmental-aspects; Soils-Agricultural-chemical-content NAL Call No.: TD427.A35C63--1993 ***************************************************************** 130. Tillage and furrow diking effects on water balance and yields of sorghum and cotton. Baumhardt, R. L.; Wendt, C. W.; Keeling, J. W. Soil-Sci-Soc-Am-j. [Madison, Wis.] Soil Science Society of America. July/Aug 1993. v. 57 (4) p. 1077-1083. Includes references. Descriptors: sorghum-bicolor; gossypium-hirsutum; rotations-; deep-tillage; chiselling-; no-tillage-; dikes-; furrows-; water-conservation; semiarid-soils; soil-water-balance; crop-yield; runoff-; rain- Abstract: Information on the combined effects of deep or no-tillage together with furrow dikes (small earthen dams constructed in the furrow) on water conservation in semiarid regions is limited. The purpose of this study was to compare the amount of rain conserved and the yields of forage sorghum [Sorghum bicolor (L.) Moench] and cotton (Gossypium hirsutum L.) as affected by furrow dikes and tillage for a 3-yr period. An Olton clay loam (fine, mixed, thermic Aridic Paleustoll) was alternately cropped to cotton and sorghum. Forage sorghum was grown in (i) disk or (ii) chisel-disk tilled 16 by 23.8 m field plots with and without furrow diking. Cotton was grown in rotation following sorghum after (i) conventional moldboard-disk or (ii) no-tillage, with furrow dikes in one-half of the tillage treatment plots. Crop yield, rainfall amount, soil water content, and runoff of natural rainfall and of simulated rainfall, applied at 80 mm h-1 for 1 h, were measured. Compared with conventionally tilled undiked plots, cumulative nonponded infiltration of simulated rainfall was significantly greater with no- tillage treatments and greater (not significant) in furrow-diked treatments. Runoff of natural rainfall from plots with furrow dikes averaged approximately 22 mm less than from undiked plots, and it was as much as 57 mm less; however, runoff from diked fields was observed. Under the conditions of this 3-yr study, diking did not significantly increase crop water use and yield, but no-tillage significantly increased crop water use and yield 1 yr. We conclude that furrow dikes installed during the growing season did not increase water conservation and crop yields under the conditions of this 3-yr study due to seasonal dike consolidation that reduced the detention capacity and to. is more effective than chisel tillage for increasing water conservation and crop yields for the conditions of this study. NAL Call No.: 56.9-So3 ***************************************************************** 131. Tillage and grass filter strip effects on sediment and chemical losses. Madison, C. E. 1992. xv, 155 leaves : ill.. Includes vita and abstract. Descriptors: Tillage-; No-tillage-; Conservation-tillage-Evaluation; Agricultural-pollution NAL Call No.: KyU Thesis-1992-Madison ***************************************************************** 132. Tillage and winter wheat residue management effects on water infiltration and storage. Dao, T. H. Soil-Sci-Soc-Am-j. [Madison, Wis.] Soil Science Society of America. Nov/Dec 1993. v. 57 (6) p. 1586-1595. Includes references. Descriptors: triticum-aestivum; winter-wheat; soil-water-balance; soil-water- content; soil-water-regimes; soil-depth; seasonal-variation; no-tillage- ; stubble-mulching; plowing-; crop-residues; infiltration-; soil- density; hydraulic-conductivity; water-conservation; precipitation-; evaporation-; oklahoma-; crop-residue-management Abstract: In traditional winter wheat (Triticum aestivum L.) cropping regions of the southern Great Plains, production constraints exist because of extreme variability in precipitation during planting periods. Intensive tillage aggravates dry early fall conditions to further hamper wheat emergence and growth. From 1983 through 1991, we determined the effects of three tillage and residue management practices on soil water storage in Bethany (fine, mixed, thermic Pachic Paleustoll) and Renfrow (fine, mixed, thermic Udertic Paleustoll) silt loams on a 2% slope near El Reno, OK. We measured soil management cumulative effects on soil bulk density and water infiltration during and after the 1990-1991 growing season. Every season, no-till soil consistently had higher volumetric water content in the 0- to 1.2-m depth, except in late fall or early spring when root-zone recharge took place for both soils. The gain was corroborated by increased water-holding capacity and decreased bulk density of no- till soils. Seasonal variability of field infiltration was more evident in plowed soil than in no-till soil. Such temporal dependence would affect surface distribution and flow of precipitation to explain differences in runoff, soil erosion, and environmental impacts of tillage systems between October and June. Water infiltration into no- till soil was significantly higher than into plowed soil at similar water contents. Under ponding, recharge occurred through macropores, directly wetting depths of 0.4 to 0.6 m of no-till soil, in. implications on profile recharge rate and solute transport in the field. Therefore, elimination of inversion tillage enhanced precipitation storage, thereby alleviating detrimental effects of climate variability in annual winter wheat cultivation. NAL Call No.: 56.9-So3 ***************************************************************** 133. Tillage effects on agrichemical movement through the Vadose Zone. Wilson, G. V.; Tyler, D. D.; Storck, N. J.; Essington, M. E.; Mueller, T. G. Tenn-farm-home-sci p.34-39. (1994). Includes references. Descriptors: soil-analysis; water-quality; macropores-; conservation-tillage; groundwater-; infiltration-; leachates-; field-tests; tennessee- NAL Call No.: 100-T25F ***************************************************************** 134. Tillage effects on fate and transport of pesticides in a Caostal Plain Soil. I. Surface runoff. Heatwole, C. D.; Zacharias, S.; Dillaha, T. A.; Mostaghimi, S. Pap-Am-Soc-Agric-Eng. St. Joseph, Mich. : American Society of Agricultural Engineers,. Winter 1991. (912543) 13 p. Paper presented at the "1991 International Winter Meeting sponsored by The American Society of Agricultural Engineers," December 17-20, 1991, Chicago, Illinois. Descriptors: water-quality; tillage- NAL Call No.: 290.9-Am32P ***************************************************************** 135. Tillage effects on SCS runoff curve numbers. Yoon, K. S.; Yoo, K. H.; Soileau, J. M. Pap-Am-Soc-Agric-Eng. St. Joseph, Mich. : American Society of Agricultural Engineers,. Winter 1991. (91-2615) 21 p. Paper presented at the 1991 International Winter Meeting sponsored by The American Society of Agricultural Engineers, December 17-20, 1991, Chicago, Illinois. Descriptors: cotton-; tillage-; probability-; runoff-; rain-; alabama- NAL Call No.: 290.9-Am32P ***************************************************************** 136. Tillage studies with a corn-soybean rotation: hydrology and sediment loss. Edwards, W. M.; Triplett, G. B.; Van Doren, D. M.; Owens, L. B.; Redmond, C. E.; Dick, W. A. Soil-Sci-Soc-Am-j. [Madison, Wis.] Soil Science Society of America. July/Aug 1993. v. 57 (4) p. 1051-1055. Includes references. Descriptors: glycine-max; zea-mays; rotations-; secale-cereale; cover-crops; conservation-tillage; no-tillage-; tillage-; runoff-; soil-; losses- from-soil; water-erosion; watersheds-; conventional-tillage Abstract: When soybean [Glycine max (L.) Merr.] is produced on sloping fields using conventional tillage and mechanical cultivation for weed control, potential soil losses are high, limiting production to relatively flat lands. With the advent of conservation tillage practices and herbicides for weed control, soybean production with tolerable soil losses on sloping fields has become technically possible. To evaluate soil loss under these new conditions, runoff and erosion were measured on six small watersheds that were farmed for 6 yr in a corn (Zea mays L.)- soybean rotation with conservation tillage. Two of the watersheds were chiseled each year, two others paraplowed, and the other two received no-tillage. A rye (Secale cereale L.) cover crop was established each winter following soybean. With average yearly rainfall of 930 mm, yearly runoff was 63.5 mm and varied between 28 and 108 mm. Average yearly soil loss for the 6-yr period was 526 kg/ha, < 10% of the allowable soil loss. Two storms caused most of the erosion, with a single storm accounting for 42% of the total measured soil loss. Earlier, these same watersheds averaged 5750 kg/ha of measured soil loss during the corn years of a corn-wheat-meadow-meadow rotation with conventional tillage. NAL Call No.: 56.9-So3 ***************************************************************** 137. Tillage studies with a corn-soybean rotation: surface runoff chemistry. Owens, L. B.; Edwards, W. M. Soil-Sci-Soc-Am-j. [Madison, Wis.] Soil Science Society of America. July/Aug 1993. v. 57 (4) p. 1055-1060. Includes references. Descriptors: glycine-max; zea-mays; rotations-; secale-cereale; cover-crops; conservation-tillage; no-tillage-; nutrients-; losses-from-soil; runoff- water; surface-water; nutrient-content; watersheds- Abstract: When soybean (Glycine max (L.) Merr.] is grown on sloping soils, there is a high potential for soil and nutrient losses. The purpose of this study was to compare nutrient losses in surface runoff across a range of watershed conditions when tillage practice was a variable. For 6 yr in east-central Ohio, nutrient concentrations and transport in surface runoff were measured from six small (< 1-ha) watersheds planted to a corn (Zea mays L.)-soybean rotation. Two watersheds were chisel plowed each year, two were paraplowed, and two received no-tillage. Rye (Secale cereale L.) provided winter cover following soybean harvest. Nitrate-N and K concentrations in surface runoff were greater during corn years than soybean years, but there was no significant difference among tillage treatments. There were no consistent differences between crops or among tillage practices for the transport of soluble P, soluble K, and total organic C (TOC). Most of the NO3-N loss was in the runoff from a small percentage of runoff events. Although NO3-N concentrations in surface runoff frequently exceeded 10 mg/L during the corn years, the actual amount of N lost was small. But because of year- to-year variation in runoff, which masked most of the differences resulting from cropping or tillage practice, there is a need for long- term research (> 6 yr) to assess the environmental risks associated with a particular management practice. NAL Call No.: 56.9-So3 ***************************************************************** 138. Use of an integrated transient flow and water budget procedure to predict and partition components of local recharge. Schuh, W. M.; Klinkebiel, D. L.; Gardner, J. C. J-hydrol v.148, p.27-60. (1993). Includes references. Descriptors: groundwater-recharge; water-budget; transient-flow; soil-water- movement; topography-; methodology-; microtopography- Abstract: A combined transient flow and water budget (TFWB) method and accounting procedure was developed and used to measure and partition the components of recharge to a sand and gravel aquifer underlying about 6.0 m of glacial till overlain by a nearly level land surface. The TFWB procedure was used to evaluate and quantify the dynamic interaction between surface recharge, till water level (at 2-4 m), and water cycling within the soil and vadose zone. Site-specific recharge activity was highly dependent upon surface microtopography. However, the homogenizing effect of the water table, measured by capillary movement of water through the vadose and soil zone, substantially offset the effects of surface and soil spatial variability and allowed relatively uniform estimates of local recharge at individual measurement sites. Substantial internal cycling of water within the soil and vadose zone was caused by the interaction of surface infiltration variability and water redistribution at the water table, even for measurement sites having little direct surface recharge activity. Through internal cycling, a single volume of water originating at the surface frequently passed through more than one soil and vadose profile during the recharge process. By applying TFWB procedures for the full soil and vadose zone between the surface to the water table, good estimates of local recharge to the Carrington aquifer could be made for the experimental area using few measurement sites. NAL Call No.: 292.8-J82 ***************************************************************** 139. Use of GIS to evaluate manure management alternatives. Young, S. E.; Richert, S. E.; Johnson, C.; Emenheiser, T. C. Pap-Am-Soc-Agric-Eng. St. Joseph, Mich. : American Society of Agricultural Engineers,. Winter 1992. (922533) 15 p. Paper presented at the "1992 International Winter Meeting sponsored by the American Society of Agricultural Engineers," December 15-18, 1992, Nashville, Tennessee. Descriptors: animal-manures; models-; land-use; uptake-; nitrogen-; phosphorus-; crop-yield; agricultural-wastes; watersheds-; pennsylvania-; geographical-information-systems NAL Call No.: 290.9-Am32P ***************************************************************** 140. Water quality impacts of conservation and nutrient management practices in Pennsylvania. Hamlett, J. M.; Epp, D. J. J-soil-water-conserv v.49, p.59-66. (1994). Includes references. Descriptors: water-quality; sediment-; nutrients-; losses-from-soil; computer- simulation; soil-management; environmental-management; environmental- impact; pennsylvania-; best-management-practices-bmp; chesapeake-bay NAL Call No.: 56.8-J822 ***************************************************************** 141. Water quality in mountain ash forests--separating the impacts of roads from those of logging operations. Grayson, R. B.; Haydon, S. R.; Jayasuriya, M. D. A.; Finlayson, B. L. J-hydrol v.150, p.459-480. (1993). In the special issue: Water Issues in Forests Today / edited by E.M. O'Loughlin and F.X. Dunin. November 22-26, 1992, Canberra, Australia. Descriptors: eucalyptus-regnans; mountain-forests; water-quality; flow-; clearcutting-; logging-effects; regeneration-; roads-; usage-; maintenance-; runoff-water; sediment-yield; catchment-hydrology; australia-; base-flow; storm-flow Abstract: The purpose of the two catchment studies reported here was to allow the effects on water quality of road use and maintenance to be separated from the effects of a logging operation. In the first project, known as the Myrtle experiment, two small catchments in an old- growth mountain ash (Eucalyptus regnans) forest were chosen for a paired catchment study of the effects on physical and chemical water quality (baseflow and stormflow) of logging under a strict code of practice and with no roads crossing runoff producing areas. In the second project, known as the Road 11 experiment, the effect on sediment production from unsealed forest roads of vehicle use and level of road maintenance was assessed. The Myrtle experiment showed that the harvesting and regeneration operation did not have a major impact on the stream physical or chemical water quality. Increases were detected in turbidity, iron and suspended solids at baseflows, but these were small in absolute terms and of similar magnitude to the measurement error. The stormflow data revealed no significant influence of the logging operation. The suspension of logging during wet weather, the protection of the runoff producing areas with buffer strips and the management of runoff from roads, snig tracks and log landing areas eliminated intrusion of contaminated runoff into the streams, thereby avoiding the adverse effects of logging. The Road 11 study determined that annual sediment production from forest roads was in the range of 50-90 t of sediment per hectare of road surface per year, with approximately two-thirds being suspended sediment and one-third coarse material. The use of gravel reduced sediment production, provided a sufficient depth of material was used. Increasing the level of road maintenance with increasing traffic load controlled. sediment production increased by approximately 40%. The results indicate that by identifying the areas that produce runoff it is possible to prevent contaminated runoff reaching the streams. Roas, on the other hand, produce large quantities of sediment, even when well maintained, so careful consideration of their placement and management is paramount. NAL Call No.: 292.8-J82 *****************************************************************
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