2007 Annual Report 1a.Objectives (from AD-416) 1. Determine crop and tillage management impacts on carbon (C) and nitrogen (N) cycling and related soil biophysical properties. Determine impacts of cropping and tillage systems on water quality and maintenance of the soil resource base. Hypothesis. No-till practices will control storm and snow-melt runoff and soil loss from drainages and watersheds under PNW conditions. 2. Develop conservation cropping and tillage systems that improve agroecosystem performance (production, stability and sustainability) and minimize adverse environmental impacts to air, water, and soil resources. 3. Determine the amount of crop residues that must remain on the land to maintain soil organic carbon and sustain production. 4. Estimate the trade-off between the short-term benefits to growers who harvest crop residues as biofuel or biomass to produce feedstocks versus the long-term benefits to soil, water, and air resources associated with retaining crop residues to build soil organic matter and sequester carbon. 5. Develop an N budget framework for N management decision-aid tools for conservation cropping systems. 1b.Approach (from AD-416) Objective 1 consists of two subobjectives. Our first subobjective is to determine the effects of C quality and quantity on soil biophysical properties and function in the seed-zone including aggregation, soil biology community dynamics and plant-microbe interactions. The research will document tillage and undercutting disturbance effects on the soil microbial populations, community structure and activity. Analyses include soil pH and electrical conductivity, aggregate distribution, bulk density and soil moisture content. Total C and N will be determined. We will investigate soil organic matter (SOM) components by fractionation, isolation and characterization. The second subobjective will be to determine tillage and cropping system effects on soil organic and inorganic N and C dynamics, and greenhouse gas emission. We will study microbially mediated transformations and the factors controlling these transformations at the landscape level. We will set up permanent areas on the USDA Conservation farm and the Cunningham Research Farm in Pullman, Washington. We will use in situ gross mineralization rates of native soil organic matter to predict the crop’s extra fertilizer needs to meet yield goals. In addition, we will monitor the microclimate of each area for parameters such as temperature, moisture and solar radiation and normalizing the N transformation data for each area and thus predict N availability over time across landscape areas. These analyses will be conducted on different cropping systems and tillage management to determine the N efficiency of each system and for predicting fertilizer needs of each system. The third objective in the overall project plan in collaboration with Pendleton, is to develop and evaluate tillage and crop residue management practices for successful conservation systems. Field experiments will consist of two N management treatments (uniform application of N fertilizer and. site-specific N management) with extensive measurements that capture the full variability of the field. Our approach will be to collect field-scale data that will allow spatial and temporal analyses. Site-specific yield and protein maps will be combined to establish realistic yield and protein goals for geo-referenced locations within a field. The combination of yield and grain protein data also provides information on the amount of N removed in the grain at harvest and will be used with GIS methods to compute variable-rate N recommendations for wheat. Replaces 5348-11120-003-00D (9/06). Associated with Pendleton, OR, project 5356-11120-002-00D. 3.Progress Report Agricultural technology required for precision N management including global positioning systems, yield and grain protein monitors, variable N rate controllers and geographical information systems software were integrated for use in research at the WSU Cook Agronomy Farm (CAF). Prescription N application maps based on field diagnostics were developed and N applied according to spatial and temporal criteria. Comparisons of uniform and precision N management were established in 2005 and continue for spring and winter wheat during 2006 and 2007. In winter wheat, precision applications reduced rates of applied N by 20% as compared to uniform applications while achieving similar yield and grain protein. Field-based decision support tools using N efficiency ratios were developed and are being tested at the CAF and with on-farm cooperators. Crop residue, energy and economic data were summarized using 369 geo-referenced data points collected on 37 ha of the WSU Cook Agronomy Farm over the past 8 years. Trade-offs between harvesting crop residues for bio-energy production and sequestering soil carbon were assessed geospatially. Preliminary results show that harvesting crop residues will negatively impact soil carbon sequestration and result in future decreases in soil C. 4.Accomplishments Increasing soil carbon storage through microbial activity. It has been suggested that, in the short term, increasing carbon inputs into soil would likely decrease CO2 in the atmosphere and reduce global warming. ARS scientist in Pullman, WA laboratory investigated how microbial enzymes were involved in this process and found significant relationships between specific enzymes and carbon compounds which enhanced carbon inputs into soil. This finding supports the concept of carbon credits for growers using such practices. Research will keep increase farm productivity for growers using management practices that increase carbon inputs into soil. NP 202 Soil Biology; Problem Area 3 Soil Carbon. 5.Significant Activities that Support Special Target Populations none 6.Technology Transfer Number of active CRADAs and MTAs 1 Number of non-peer reviewed presentations and proceedings 17 Number of newspaper articles and other presentations for non-science audiences 12 Review Publications Bell, J.M., Smith, J.L., Bailey, V.L., Bolton Jr., H.. 2003. Priming effect and C storage in semi-arid no-till spring crop rotations. Biology and Fertility of Soils 37:237-244. Link, S.O., Smith, J.L., Bolton Jr., H., Halvorson, J.J. 2003. A reciprocal transplant experiment within a climatic gradient in a semi-arid shrub-steppe ecosystem: effects on bunchgrass growth and reproduction, soil carbon, and soil nitrogen. Global Change Biology 9:1097-1105. Smith, J.L., Collins, H.P. Managing soil microorganisms and their processes. Book Chapter pp 471-502. 2007. Huggins, D.R., Allmaras, R.R., Clapp, C.E., Lamb, J.A., Randall, G.W. Corn-soybean sequence and tillage effects on soil carbon dynamics and storage. Soil Science Society of America Journal 71:145-154. 2007. Kennedy, A.C., Stubbs, T.L. Management effects on the incidence of jointed goatgrass inhibitory rhizobacteria. Biological Control 40:213-221. 2007.