2006 Annual Report 1.What major problem or issue is being resolved and how are you resolving it (summarize project aims and objectives)? How serious is the problem? Why does it matter? This project is part of National Program (NP) 202, Soil Resource Management. Pacific Northwest soils, as in many arid irrigated areas worldwide, are low in organic matter, poorly aggregated, very erosive, easily crusted or compacted, limited in nutrient holding capacity and often high in calcium carbonate. The soils tend to be freely drained and overlie fissured basalt, increasing risks of chemical and organism movement to groundwater and re-emergence in seeps and springs. The Pacific Northwest has a cool arid climate. Topography is often rolling, with irrigated slopes up to 10%. Large areas are still furrow-irrigated due to field size, sprinkler cost, or for crop disease prevention. Confined feeding of dairy, beef cattle and hogs is increasing rapidly, impacting crop choices, nutrient management and surface and groundwater protection. Water is limited and energy cost for pumping and other operations is rising. Carbon dioxide sequestration potential is high, but not well documented, especially regarding mineral carbonates. Much remains unknown about effects of manure application on runoff nutrient loss under furrow irrigation or effects on soil properties. Irrigation grows over one-third of the yield and nearly half of agriculture's economic value on one-sixth of the land base. Irrigation of arid and semi-arid land provides production security against regional disasters in rainfed agriculture, like the 1993 Midwestern floods, and repeated persistent continental droughts. Irrigation grows one-third of man's food crop on 4% of the arable cropping base, and its high output reduces need to develop new farm land from rainforests, wetlands and grasslands. Yet, arid zone irrigated agriculture, is often on fragile soils, demanding adept soil and water management to protect sustainability. Because irrigated agriculture is typically more intensive than rainfed agriculture, input management is more demanding and the potential for soil degradation from poor management is greater. Runoff and return flows can alter riparian receiving water quality, impacting aquatic biota. New practices to conserve soil and protect surface water are needed. The original seven objectives of this project relate to NP 202, Soil Resource Management. 2.List by year the currently approved milestones (indicators of research progress) Year 1 (FY2001) Objective 1. Develop soil and plant canopy multi-sensed spectral reflectance based determination of soil surface wetness for precision agriculture (Soil water investigations): Establish remote sensing sites, begin measurements. Objective 2. Determine irrigation impacts on soil Carbon (C), via C storage, trace greenhouse gas release and dissolved organic carbon (DOC) movement to the vadose zone (Irrigated soil C comparison and DOC fate investigations): Complete site soil carbon analysis, obtain data, summarize. Objective 3. Develop environmentally and economically sound tillage, irrigation and residue management practices for crops under irrigation (Conservation tillage investigations): Complete soil chemical analysis. Objective 4. Develop new and improved strategies and practices for infiltration, runoff and erosion management and prediction under irrigation as affected by soil and water properties that include manure, compost, crop residue, natural and synthetic amendments, slope and temperature (Structure infiltration, runoff, erosion studies; model analysis or development): Site selection and data collection. Objective 5. Determine meteorological and soil factors affecting soil crusting and seedling emergence and investigate amelioration methods (Soil crusting factors and prevention investigations): Design and initiate studies. Objective 6. Develop improved nutrient management practices for sustainable irrigated agricultural production systems (Nutrients and runoff investigation): Establish sites and begin simulator runs. Objective 7. Identify soil-plant-animal nutrient interactions, fate and transformations in irrigated agricultural production systems (Nutrient cycling in animal forage investigations): Conduct field work and lab analysis. Year 2 (FY2002) Objective 1. Soil water investigations: Conduct field studies; analyze data. Objective 2. Irrigated soil C comparison and DOC fate investigations: Analyze data, develop preliminary findings. Objective 3. Conservation tillage investigations: Initiate erosion and runoff analysis. Objective 4. Structure infiltration, runoff, erosion studies; model analysis or development: Analyze data, run model analysis. Objective 5. Soil crusting factors and prevention investigations: Continue lab anticrustant experiments. Objective 6. Nutrients and runoff investigation: Conduct field and simulator studies. Objective 7. Nutrient cycling in animal forage investigations: Complete field work and lab analysis. Year 3 (FY2003) Objective 1. Soil water investigations: Complete field studies; analyze data; prepare preliminary reports. Objective 2. Irrigated soil C comparison and DOC fate investigations: Examine preliminary findings; report preliminary findings at meetings. Objective 3. Conservation tillage investigations: Complete erosion and runoff analysis. Objective 4. Structure infiltration, runoff, erosion studies; model analysis or development: Data and model analysis and preliminary reports, establish follow-up studies. Objective 5. Soil crusting factors and prevention investigations: Analyze lab anticrustant experiments, begin field studies. Objective 6. Nutrients and runoff investigation: Conduct field and simulator studies, chemical analysis, runoff summaries. Objective 7. Nutrient cycling in animal forage investigations: Begin data reduction and summaries. Year 4 (FY2004) Objective 1. Soil water investigations: Meeting presentations, draft manuscripts. Objective 2. Irrigated soil C comparison and DOC fate investigations: Meeting presentations, draft manuscripts. Objective 3. Conservation tillage investigations: Meeting presentations. Objective 4. Structure infiltration, runoff, erosion studies; model analysis or development: Enhance or modify models, extend to other practices, do follow-up studies. Objective 5. Soil crusting factors and prevention investigations: Evaluate crust inhibitors, meeting reports, plan follow-up studies. Objective 6. Nutrients and runoff investigation: Data reduction and analysis; meetings reports. Objective 7. Nutrient cycling in animal forage investigations: Interpret results, meetings reports. Year 5 (FY2005) Objective 1. Soil water investigations: Begin technology transfer; identify concepts for continuing research. Objective 2. Irrigated soil C comparison and DOC fate investigations: Begin technology transfer; identify concepts for continuing research. Objective 3. Conservation tillage investigations: Draft one or more manuscripts. Objective 4. Structure infiltration, runoff, erosion studies; model analysis or development: Draft one or more manuscripts, deploy model, begin technology transfer. Objective 5. Soil crusting factors and prevention investigations: Draft one or more manuscripts. Objective 6. Nutrients and runoff investigation: Draft one or more manuscripts. Objective 7. Nutrient cycling in animal forage investigations: Draft one or more manuscripts, begin technology transfer. Year 6 (FY2006) Objective 1. Soil water investigations: Begin technology transfer; identify concepts for continuing research; continue progress on FY 2005 milestones and develop project plan for the next five-year cycle. Objective 2. Irrigated soil C comparison and DOC fate investigations: Begin technology transfer; identify concepts for continuing research; continue progress on FY 2005 milestones and develop project plan for the next five-year cycle. Objective 3. Conservation tillage investigations: Draft one or more manuscripts; continue progress on FY 2005 milestones and develop project plan for the next five-year cycle. Objective 4. Structure infiltration, runoff, erosion studies; model analysis or development: Draft one or more manuscripts, deploy model, begin technology transfer; continue progress on FY 2005 milestones and develop project plan for the next five-year cycle. Objective 5. Soil crusting factors and prevention investigations: Draft one or more manuscripts; continue progress on FY 2005 milestones and develop project plan for the next five-year cycle. Objective 6. Nutrients and runoff investigation: Draft one or more manuscripts; continue progress on FY 2005 milestones and develop project plan for the next five-year cycle. Objective 7. Nutrient cycling in animal forage investigations: Draft one or more manuscripts, begin technology transfer; continue progress on FY 2005 milestones and develop project plan for the next five-year cycle. 4a.List the single most significant research accomplishment during FY 2006. Stable 13C and 15N isotopes provide estimates of PAM content in soil. We determined anionic polyacrylamide concentrations and degradation rates using natural abundance of stable isotopes 13C and 15N. Polyacrylamide (PAM) is an increasingly popular soil and water amendment for clarification of turbid water in ponds and irrigation return flows and for preventing erosion, however, measuring the amount of PAM left in soil or its rate of degradation has been hampered by lack of sensitive analytical techniques once PAM has irreversibly adsorbed to soil surfaces, making some environmental regulators wary of potential long term accumulation effects. ARS Soil Scientists from Kimberly, Idaho, treated four different soils of widely different mineralogy and texture from across the US with anionic PAM at rates of 0, 10, 100, 1000 and 10,000 mg PAM per/kg soil, and isotope ratios were analyzed by two separate laboratories. In Portnuef silt loam from Kimberly, ID a 0.99 correlation was found between the anionic PAM concentration in soil and its 13C/12C ratio pointing the way to use of the relationship to calculate PAM degradation rate in situ, which can be used to further verify PAM safety for use in preventing erosion and protecting surface water quality. (National Program Component Soil Conservation and Restoration; Problem Statement 8: Control of Soil Erosion) 4b.List other significant research accomplishment(s), if any. Organic Carbon Movement. Dissolved organic carbon (DOC) movement into soil below the root zone (the vadose zone) was quantified and identified. This DOC may be a potential substrate for deep profile denitrification. The Kimberly ARS Scientists who conducted the research have noted that this deep movement of DOC may explain how bacterial denitrification can proceed in highly mineral substrata where the potential for nitrogen removal from groundwater through dentrification had previously not been seen as feasible. (National Program Component Soil Conservation and Restoration; Problem Statement 3: Soil Carbon Measurement, Dynamics and Management) Polyacrylamide (PAM) use for Erosion Control and Water Quality. Numerous aspects of PAM use to manage irrigation-induced erosion and infiltration determined through extensive research; these include reduced sediment, nutrient, agrichemical, biological oxygen demand (BOD), micro-organism and weed seed loads of PAM-treated runoff, leading to reduced weed and pathogen dispersion and reduced need for pesticide application, as well as overall improved runoff quality; also the first Scanning Electron Microscope images of PAM coating on field treated soils were obtained and published, confirming many insights about PAM mode of action. This knowledge has greatly improved management options for irrigated agriculture. The team of Kimberly ARS scientists who accumulated these finding have noted that as PAM technology is applied to more irrigated acres production will benefit while protecting the environment. (National Program Component Soil Conservation and Restoration; Problem Statement 8: Control of Soil Erosion) Irrigation Sequesters Carbon. Irrigation of arid soils was shown to increase total soil carbon contents (organic plus inorganic) regardless of soil management system; soil organic carbon increased in pasture and reduced tillage irrigated systems. These increases were above natural baseline soil carbon contents, not merely remediation of carbon lost to oxidation, which is the effect typically reported for humid zone soils. The Kimberly, ARS Scientists who conducted the research point to the potential application of these findings to develop new strategies and policies to take better advantage of irrigated agriculture’s unique ability reduce atmospheric carbon dioxide via carbon sequestration in soil and help combat global warming. (National Program Component Soil Conservation and Restoration; Problem Statement 3: Soil Carbon Measurement, Dynamics and Management; Focus Area 3: Effects of Management on Soil Carbon) Phosphorus Sorption Characterization. The definition of phosphorus (P) adsorption-desorption characteristics for arid zone calcareous soils were improved. These characteristics are essential for determining P loading limits on arid calcareous soils, whose chemistry differs significantly from more acid, more organic soils from which most current information has been derived. The work was conducted by ARS soil scientists in Kimberly, ID. Continuing work with manure from a variety of animal sources is providing quantitative information to help develop a practical P index to help manage manure application across the Pacific Northwest, the fastest growing dairy area in the western hemisphere, with over 8 million tons of manure from dairies in Idaho alone to be spread on very limited cropland resources. The new information provides insights that will help develop management to reduce P losses in irrigation runoff, thereby protecting surface and groundwater resources. (National Program Component Nutrient Management; Problem Statement 4: Nutrient Management for Crop Production and Environmental Protection; Focus Area 1: Decision Support Tools for Improved Nutrient Management) Animals Prefer Afternoon-cut Forages. Animal preference for and improved nutritional value of PM-harvested forages was documented for a wide variety of forage types and herbivorous animals. The work is important for maximizing the efficiency and production of large scale animal feeding operation which operate in a highly competitive economic climate. The research was performed by ARS scientists in Kimberly, Idaho and will lead to improved weight gain and better lactation for a no-cost management adjustment, greatly improving production and profitability. (National Program Component Nutrient Management; Problem Statement 4: Nutrient Management for Crop Production and Environmental Protection; Focus Area 1: Decision Support Tools for Improved Nutrient Management) Soil Strength Dependence on Water Content. Detailed determination of the dependence of soil strength on water content and bulk density was conducted by ARS soil scientists in Kimberly, ID. The work helped explain the variation in hardness of soil in fields at a given water content and bulk density, which significantly affects the ability of crop roots to penetrate soil in order to provide the crop with water and nutrients. This research led to recognition of a possible previously unnoticed hysteretic dependence of soil strength on water content, with strength varying depending on length of time at a given rehydration value from dry soil, meaning that soil rehydrated immediately after prolonged drying may still prevent root penetration, until cementing agents that hold soil particles together have had sufficient time to dissolve. (National Program Component Soil Conservation and Restoration; Problem Statement 2: Soil Management to Improve Soil Structure and Hydraulic Properties) 4c.List significant activities that support special target populations. The accomplishments under this project have broad benefit and application across all of society including small farms, the socially disadvantaged and other identified special target populations. NWISRL presented research findings and ARS program descriptions to the Yakama Indian Nation (April 2001 and January 2006) in Toppenish, WA, and to the Northwest Intertribal Council meeting (March 14, 2002) in Pocatello, ID; these presentations included offers of technical consultation for irrigation-related management technologies and development of specific research to meet tribal needs. 4d.Progress report. Several major contributions have resulted from work performed under this CRIS to date. Dissolved organic carbon (DOC) movement into the vadose zone has been quantified and identified as a potential substrate for deep profile denitrification. Animal preference for and improved nutritional value of PM harvested forages has been documented for a wide variety of forage types and herbivorous animals, leading to improved weight gain and better lactation for a no-cost management adjustment. Numerous aspects of PAM use to manage irrigation-induced erosion and infiltration have greatly improved management options for irrigated agriculture while protecting the environment; these include reduced sediment, nutrient, agrichemical, biological oxygen demand (BOD), micro-organism and weed seed loads of PAM treated runoff, leading to reduced weed and pathogen dispersion and reduced need for pesticide application, as well as overall improved runoff quality. The first Scanning Electron Microscope images of PAM coating on field treated soils were obtained and published, confirming many insights about PAM mode of action. Irrigation of arid soils is shown to increase total soil carbon contents (organic plus inorganic) regardless of soil management systems; soil organic carbon increased in pasture and reduced tillage irrigated systems. These increases were above natural baseline soil carbon contents, not merely remediation of carbon lost to oxidation, which is the effect typically reported for humid zone soils. Improvements in definition of phosphorus (P) adsorption-desorption characteristics for arid zone calcareous soils provide insights that will help develop management to reduce P losses in irrigation runoff, thereby protecting surface and groundwater resources. Continuing work with manure from a variety of animal sources is providing quantitative information to help develop a practical P index to help manage manure application across the Pacific Northwest, the fastest growing dairy area in the western hemisphere, with over 8 million tons of manure from dairies in Idaho alone to be spread on very limited cropland resources. Soil strength studies have led to recognition of a possible previously unnoticed hysteretic dependence of soil strength on water content, with strength varying depending on length of time at a given rehydration value from dry soil. 5.Describe the major accomplishments to date and their predicted or actual impact. Concerns over environmental phosphorus (P) enrichment make development of a robust analytical technique to rapidly and accurately assess the various forms of P present in manure and animal feeds highly desirable. A NWISRL scientist used Nuclear Magnetic Resonance (NMR) to characterize the chemical forms of phosphorous present in broiler litter, cattle manure and swine manure extracts. This represents a potential improvement over chromatographic and other procedures for simultaneous rapid determination of multiple P compounds with minimal sample preparation and handling. The eventual improvement of NMR technology for P analysis could greatly facilitate broad spectrum P analysis of a wide range of sample types, including water, animal feeds, plant tissue and manure, allowing development of improved management strategies to protect the environment. Relation to project plan objectives and National Program Components: Develop improved nutrient management practices for sustainable irrigated agricultural production systems (NP202.C2.PA1.G1,2&3;PA2. G1;PA3.G1,2&3; C3.PA1.G2). Because land application of manure is associated with eutrophication of surface waters, methods to better predict nutrient availability/solubility from manure need to be developed to determine its nutrient supplying power and risk of off-site losses of manure nutrients. At the NWISRL, weighting factors are being developed for inclusion in P site index risk assessments in order to better quantify the potential risk of P losses associated with land application of various manures and other organic P sources. Preliminary Phosphorus Source Coefficients (PSCs) were developed to assign relative risk to various organic P sources that are typically land applied, and testing of the concept on calcareous soils in the Pacific Northwest supported the PSCs developed. This accomplishment will facilitate prediction of off-site P transport from manure treated soils which is a major factor affecting pollution. Relation to project plan objectives and National Program Components: Develop improved nutrient management practices for sustainable irrigated agricultural production systems (NP202.C2.PA1.G1,2&3;PA2. G1;PA3.G1,2&3; C3.PA1.G2). Little is known about the magnitude and nature of DOC movement or losses from irrigated arid zone soils. NWISRL scientists measured DOC concentration in water percolating beyond the root zone of furrow irrigated crops in a highly calcareous soil. They determined that the 56.4 kg/ha DOC leached below the root zone. This is sufficient to supply energy for denitrification under anaerobic soil conditions. Relation to project plan objectives and National Program Components: Determine irrigation impacts on soil Carbon, via C storage, trace greenhouse gas release and dissolved organic carbon (DOC) movement to the vadose zone (NP202.C2.PA4.G1&2;C3.PA3.G2). Zinc deficiency occurs in many of the common bean (Phaeseolus vulgaris L.) production regions in the U.S. NWISRL scientists evaluated the inheritance of susceptibility to zinc deficiency in the common bean in collaboration with the University of Idaho. Field and greenhouse studies showed that a single dominant gene controls susceptibility to zinc deficiency in the common bean. This will facilitate the transfer of zinc deficiency-resistance to new genotypes and in existing susceptible genotypes, and allow planting resistant cultivars on low zinc available soils. Relation to project plan objectives and National Program Components: Develop improved nutrient management practices for sustainable irrigated agricultural production systems (NP202.C2.PA1.G1,2&3;PA2. G1;PA3.G1,2&3; C3.PA1.G2). Soil crusting is a serious problem affecting stand establishment and resulting yield of sugarbeet nationwide. NWISRL scientists conducted lab, field and controlled-environment trials to quantify the effects of crust-causing rain and irrigation and compare the effectiveness of crust prevention strategies. In three studies, seedling emergence increased 22%, however, they observed discrepancies between field, lab and controlled environment studies, attributed to confounding influences of humidity, temperature, light and other factors which they are attempting to sort out in controlled environment chamber studies. The improved stand establishment could increase net income of the region's growers by $0.7 to $2 million annually and improve U.S. sugarbeet production and profitability nationally. Relation to project plan objectives and National Program Components: Determine meteorological and soil factors affecting soil crusting and seedling emergence and investigate amelioration methods (NP202.C1.PA3.G5;C5.PA1.G2). Animal preference influences feed use, intake and weight gain. An NWISRL scientist found that when given a choice, daily consumption averaged 97% for pellets made from afternoon-cut alfalfa in the first three weeks of feeding, paralleling findings for of preference for afternoon forage cuttings in horses and lactating dairy cows (cooperatively with U.S. Dairy Forage Research Center, Madison, WI). Harvest scheduling is a high-benefit, no-cost farm management option that can improve farm profits with little or no disruption or adverse impact on animal rearing practices, enhancing forage value and animal productivity by 5 to 10%. Relation to project plan objectives and National Program Components: Identify soil-plant-animal nutrient interactions, fate and transformations in irrigated agricultural production systems (NP202.C2.PA2.G1.PA2.G1). Weed seed content of runoff water is a serious problem leading to the spread of weeds on farm and among farms via capture and use of tail water for further irrigation downstream. A joint NWISRL/University of Idaho two-year study of polyacrylamide (PAM) effects on weed seed sequestration, in-field weed ecology and herbicide movement in soil in an edible dry bean crop was completed as part of the Ph.D. dissertation research for a University of Idaho graduate student. The thesis, "The influence of polyacrylamide on the movement of soil-applied herbicides in furrow-irrigated beans," is being written in a format for journal submission and quantifies PAM's ability to reduce weed seed loss in runoff by typically 90%. The results from this and a previous study in corn are already used extensively for technology transfer by NWISRL personnel and University of Idaho cooperators and have the potential to greatly reduce farmer weed management costs the extent of herbicide loading of the environment. Relation to project plan objectives and National Program Components: Develop new and improved strategies and practices for infiltration, runoff and erosion management and prediction under irrigation as affected by soil and water properties that include manure, compost, crop residue, natural and synthetic amendments, slope and temperature. (NP202.C1.PA1.G1&2;G7.PA3.G5;C3.PA1.G2). Polyacrylamide (PAM) is known to increase water viscosity but there is little understanding of how significant these effects are with respect to irrigation water management. Lab, greenhouse and field studies initiated in 2001 cooperatively among an NWISRL scientist and a Massey University (New Zealand) scientist looked at effects of a range of PAM concentrations on soil hydraulic conductivity, wetting patterns and soil water retention properties. Preliminary results suggest that changes in conductivity and water retention are multi-modal across concentrations ranging from a half part per million to over twenty parts per million and hold potential for creating specific management of erosion, infiltration (increase or decrease), and improved root zone water and nutrient availability depending on soil textural and structural properties and the concentration of PAM used. These results can help improve water and nutrient conservation and lead to strategies that will raise crop yields, especially on coarse textured soils while protecting groundwater from nutrient leaching. Relation to project plan objectives and National Program Components: Develop new and improved strategies and practices for infiltration, runoff and erosion management and prediction under irrigation as affected by soil and water properties that include manure, compost, crop residue, natural and synthetic amendments, slope and temperature. (NP202.C1.PA1.G1&2;G7.PA3.G5;C3.PA1.G2). PAM effects on soil and water have been recognized for many years, but physical evidence of its mode of expression has generally been indirect. A NWISRL scientist and a New Zealand Landcare scientist cooperated to obtain scanning electron micrographs (SEM) of soil particles and aggregates treated with dilute concentrations of PAM in irrigation water. The SEMs obtained distinctly show PAM polymer filaments overlying and holding together soil particles and aggregates in a loose net-like configuration, allowing movement of water while strengthening soil structure to resist water erosion, providing the first direct evidence of PAM's mode of soil erosion control and infiltration enhancement in irrigated soils. The SEM imagery is in press at the Journal of Soil and Water Conservation and is used widely in PAM seminars, field days, workshops and popular publications, facilitating farmer adoption. Relation to project plan objectives and National Program Components: Develop new and improved strategies and practices for infiltration, runoff and erosion management and prediction under irrigation as affected by soil and water properties that include manure, compost, crop residue, natural and synthetic amendments, slope and temperature. (NP202.C1.PA1.G1&2;G7.PA3.G5;C3.PA1.G2). In Idaho, eight million tons of dairy manure are produced each year, most of which is applied to irrigated fields, risking nutrient and pathogen contamination of surface waters via irrigation runoff. Kimberly ARS scientists studied the application timing and tillage effects on runoff losses. Delaying furrow irrigation on fields with late-summer or fall applied manure until after spring tillage, reduced nitrate nitrogen and ammonium nitrogen runoff losses by 90 to 95%, relative to fall-irrigation values, whereas spring rototill and plowed plots produced similar runoff nutrient losses. This knowledge will contribute to developing manure management guidelines to minimize nutrient contamination of surface waters by irrigation runoff. Relation to project plan objectives and National Program Components: Develop improved nutrient management practices for sustainable irrigated agricultural production systems (NP202.C2.PA1.G1,2&3;PA2. G1;PA3.G1,2&3; C3.PA1.G2). Previous Kimberly ARS research showed irrigated management systems can increase the amount of carbon (C) in soils, benefiting the atmosphere, but it was unclear how they influence soil microbes. NWISRL scientists measured C stored in Idaho soils having long term histories of native sagebrush vegetation (NSB), irrigated moldboard plowed crops (IMP), irrigated conservation -chisel- tilled crops (ICT) and irrigated pasture systems (IP) and analyzed for microbiological influences. While findings were complex among management regimes, irrigated agriculture especially IP and ICT generally had greater soil microbial activity and biomass, despite shifts in community structure from the NSB baselines, with soil C concentrations showing strong positive correlations for eubacterial diversity. These results validate the environmental benefits of irrigated agriculture at a soil microbial level, and suggest particular enhancements are achievable in pasture and conservation tillage regimes. Relation to project plan objectives and National Program Components: Develop environmentally and economically sound tillage, irrigation and residue management practices for crops under irrigation (NP202.C1.PA1.G1&2,7;PA3.G5;C2.PA1.G1). Efforts to manage soil for crop production and pollution prevention are impeded by our poor understanding of the chemical properties controlling P sorption in semi-arid calcareous Pacific Northwest soils. NWISRL scientists looked for the equilibrium P concentration at which precipitation begins to dominate the sorption/precipitation reactions. They found that this concentration is governed by pH, organic carbon, and more by the amount of organically complexed iron and manganese than by the amount of calcium or calcium carbonate in these soils. These data will help determine how manuring and other organic matter additions to soil affect P solubility and resulting plant availability or off-site P transport from these soils which is a major factor affecting pollution. Relation to project plan objectives and National Program Components: Develop improved nutrient management practices for sustainable irrigated agricultural production systems (NP202.C2.PA1.G1,2&3;PA2. G1;PA3.G1,2&3; C3.PA1.G2). There is a need to document and quantify the carbon balance of arid zone irrigated agriculture which can sequester soil carbon above natural ecosystem baseline levels (something rainfed ag systems cannot do). NWISRL scientists in cooperation with University of Idaho assessed soil inorganic and organic carbon pools on the Portneuf soil in Idaho. They determined that net soil organic carbon storage for four management systems decreased in the order Irrigated Pasture>Irrigated Conservation Tillage>Irrigated Moldboard Plowing>Native Sage Brush, whereas for total soil carbon (organic plus inorganic) the ranking was Irrigated Moldboard Plow>Irrigated Conservation Tillage>Irrigated Pasture>Native Sage Brush. These data, which are in press at "Environmental Management," confirm the ability of irrigation in arid systems to accumulate soil carbon above natural baselines, and provide a new insight for policy makers and long term land use and resource development strategies to benefit American agriculture and combat global warming. Relation to project plan objectives and National Program Components: Determine irrigation impacts on soil Carbon, via C storage, trace greenhouse gas release and dissolved organic carbon (DOC) movement to the vadose zone (NP202.C2.PA4.G1&2;C3.PA3.G2). Results from a long term field study showed that continued massive applications to soil (up to 6 tons per acre) of anionic high molecular weight polyacrylamide (PAM) had only minor and inconsistent affects on soil microflora, alleviating concerns that despite large environmental and production benefits at far lower PAM application rates that PAM accumulation might seriously harm soil micro ecology. Despite enormous benefits of PAM use for erosion control and water quality protection at very low cost, some land managers and public agencies have hesitated adopting or promoting PAM-use because of lack of information on the potential long term consequences on soil micro-ecology if PAM accumulated in the soil. NWISRL scientists ran a six-year field experiment that added a ton of PAM per acre to soil each year and monitored the effects on soil properties, including microbial analyses that were accomplished with a collaborator from the University of Delaware. They showed that on two of three sampling dates active microbial biomass was 27-48% greater in untreated soil, but on a third sampling date there was no difference, and they found no differences in soil microbial community on any sampling date using fatty acid profile analysis, whereas Biolog plating only showed a community shift on one of the three sampling dates. Since typical PAM application rates in agriculture are 10-20 pounds per acre per year (three orders of magnitude less than this study used), and since PAM breaks down at rates of at least 10% per year (meaning maximum accumulation of PAM in agricultural use is two orders of magnitude less than this study), this study shows there is no basis for reasonable concern that PAM application will adversely affect soil microflora. This knowledge should greatly facilitate promotion of PAM use for erosion control and water quality protection. Relation to project plan objectives and National Program Components: Develop new and improved strategies and practices for infiltration, runoff and erosion management and prediction under irrigation as affected by soil and water properties that include manure, compost, crop residue, natural and synthetic amendments, slope and temperature. (NP202.C1.PA1.G1&2;G7.PA3.G5;C3.PA1.G2). Direct seeding dry bean following spring wheat reduced furrow irrigation runoff and soil loss but high amounts of residue in furrows slowed water flow and increased soluble phosphorus loss. Previous research showed that using conservation tillage with corn and small grain under furrow irrigation can reduce soil erosion and increase net income, but conservation tillage had not been tested with dry bean. Four tillage treatments were evaluated by NWISRL scientists for planting dry bean after spring wheat. Direct seeding had the most residue in furrows, which slowed water advance and made furrow irrigation difficult. The three tilled treatments (disk or chisel plow) had similar crop yields, residue amounts and phosphorus losses. This study demonstrated that dry bean could be grown with conservation tillage, but direct seeding is not recommended following high residue crops. Relation to project plan objectives and National Program Components: Develop environmentally and economically sound tillage, irrigation and residue management practices for crops under irrigation (NP202.C1.PA1.G1&2,7;PA3.G5;C2.PA1.G1). A substantial body of data is being obtained showing that cattle, sheep and goats prefer evening cut to morning cut forage, possibly prompted by the diurnal changes in simple sugars in the growing plant. Livestock producers have often experienced inconsistent acceptance by animals of otherwise similar forages, and these findings provide an explanation for that animal behavior as well as identifying an additional management tool to identify higher forage quality and value and to increase animal productivity. Preference studies have been conducted by NWISRL researchers who produced, harvested and shipped the hay to ARS cooperators at Raleigh, NC; Watkinsville, GA; Dubois, ID; and Madison, WI; who conducted animal feeding and lab characterization of the hays. Application of these findings could increase forage value and animal production efficiency with an estimated increase in milk production in western states valued at $200 to $300 million. Relation to project plan objectives and National Program Components: Identify soil-plant-animal nutrient interactions, fate and transformations in irrigated agricultural production systems (NP202.C2.PA2.G1.PA2.G1). A three-year study is nearing completion that explores the use of water soluble linear forms and gel-forming crosslinked forms of polyacrylamide (PAM) soil amendments to stabilize subsoil tillage disruption for improved crop growth at longer intervals between subsoil operations. Many soils have significant barriers to rooting at shallow depths that require subsoil tillage disruption to optimize yield potential, especially in situations where water is limiting for all or part of a growing season; however, subsoiling effectiveness is often limited to short durations because of soil reconsolidation, especially in areas of high irrigation application or high rainfall. NWISRL scientists conducted a three-year field experiment in which several polymer treatments were applied to the soil immediately behind the subsoiler tillage shank allowing monitoring of soil strength and structural properties over time; a parallel study was coordinated with ARS collaborators in Florence, SC. Preliminary results indicate that polymer additions may lengthen the duration of subsoil disruption which could enhance and prolong the effectiveness for crop response, improving production and lowering subsoiling frequency requirements which would also save energy. Relation to project plan objectives and National Program Components: Develop environmentally and economically sound tillage, irrigation and residue management practices for crops under irrigation (NP202.C1.PA1.G1&2,7;PA3.G5;C2.PA1.G1). 6.What science and/or technologies have been transferred and to whom? When is the science and/or technology likely to become available to the end-user (industry, farmer, other scientists)? What are the constraints, if known, to the adoption and durability of the technology products? Results from PAM weed seed and PAM weed seeds in dry bean studies have been widely reported to farmers and at scientific meetings in the U.S. and internationally. Information pertaining to carbon sequestration in irrigated agriculture has been published and presented at scientific meetings and for use in the Idaho carbon sequestration task force and is being shared with irrigation extension personnel. DOC study has been completed and results summarized; preliminary findings have been shared at technical meetings. Several PM-harvest forage studies have been completed and the technology has been transferred nationally and internationally at scientific meetings, to user groups and to farmers and ranchers. Soil organic carbon sequestration study samples were analyzed for additional soil properties. Analyses show significant increases in carbon storage as inorganic carbonates as well as substantially increased microbial activity and diversity in land converted from desert native sagebrush to any form of irrigated agriculture. These findings have been reported to farmers and to scientific meetings. Compost and manure study results were presented at a land application conference in 2004. 7.List your most important publications in the popular press and presentations to organizations and articles written about your work. (NOTE: List your peer reviewed publications below). “Soil Compaction Management,” Far West Agribusiness Association 32nd Annual Fertilizer & Chemical Conference, Jackpot, NV, January 10-12, 2005. “Contrasting Perspectives on the Soil Quality Concept” Seminar, University of Idaho Department of Plant, Soil and Entomological Sciences, Moscow, ID, February 11, 2005. “Irrigated Agriculture Increases Soil Carbon and Microbial Biomass” Idaho Governor’s Advisory Council on Soil Carbon Sequestration, Moscow, ID, March 15, 2005. “Balancing Perspectives in Soil and Environmental Management,” 2005 Albrecht Lecture, University of Missouri, Colombia, MO, April 25, 2005. “Soil Management for Water Quality Protection Presentation,” Crop Production Challenge, a joint technical field day for NWISRL and University of Idaho Kimberly R&E Center, July 7, 2005. Brief overview of the NWISRL soil and water research programs, Chamber of Commerce Water Tour, July 7, 2005. “PAMs can save water and curb pollution” by Don Dale, Western Farmer-Stockman, January 2005. Review Publications Entry, J.A., Leytem, A.B., Verwey, S.A. 2005. Influence of solid dairy manure and compost with and without alum on survival of indicator bacteria in soil and on potato. Environmental Pollution. 138:212-218. Yang, C., Mills, D., Mathee, K., Wang, Y., Jayachandran, K., Sikaroodi, M., Gillevet, P., Entry, J.A., Narasimhan, G. 2005. An ecoinformatics tool for microbial community studies: Supervised classification of amplicon length heterogeneity (ALH) profiles of 16s rRNA. Journal of Microbiological Methods. 65:49-62. Lehrsch, G.A., Kincaid, D.C. 2006. Sprinkler droplet energy effects on soil penetration resistance and aggregate stability and size distribution. Soil Science. 171(6):435-447. Brown, B., Johnson-Maynard, J., Leytem, A.B., Lentz, R.D., Lehrsch, G.A. 2006. Dairy manure/compost n release for sugarbeets and subsequent wheat. Proceedings of the Idaho Nutrient Management Conference. III:13-18. Sojka, R.E., Entry, J.A., Furhmann, J.J. 2006. The influence of high application rates of polyacrlyamide on microbial diversity in an agricultural soil. Applied Soil Ecology. 32:243-252.