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ARS Home » Pacific West Area » Pullman, Washington » Northwest Sustainable Agroecosystems Research » Research » Research Project #419046

Research Project: Mitigating Agricultural Sources of Particulate Matter and Greenhouse Gas Emissions in the Pacific Northwest

Location: Northwest Sustainable Agroecosystems Research

2014 Annual Report


1a. Objectives (from AD-416):
Objective 1. Characterize key environmental and management drivers of agricultural wind-blown dust and PM10/PM2.5 emissions that will improve process-oriented models and decision aids. Sub-obj. 1.a. Determine the relationship between soil wetness/crusting and emission of windblown dust and PM10/PM2.5. Sub-obj. 1.b. Determine the biotic factors driving aggregate formation and stability in dryland soils and their influence on windblown dust and PM10/PM2.5 emissions. Sub-obj. 1.c. Determine the effect of wind erosion and management practices on soil organic matter (SOM), soil biological communities and other soil characteristics. Objective 2. Develop techniques for identifying sources of PM10/PM2.5 to better associate management practices with PM10/PM2.5 emissions and to corroborate models. Sub-obj. 2.a. Determine the efficacy of FAME and tracer methods in discerning soils contained in various mixtures. Sub-obj. 2.b. Determine point source soil movement and FAME efficacy using known microbial tracers. Sub-obj. 2.c. Determine the effectiveness of using FAME fingerprinting to corroborate the Columbia Plateau regional dust transport model. Objective 3. Characterize roles of environmental and management drivers on soil C and N cycling as factors regulating GHG (N2O, CO2) emissions from agricultural soils. Sub-obj. 3.a. Determine soil C sequestration rates and CO2 flux as influenced by agroecosystem drivers (e.g. soil, topography, micro-climate, organisms, management). Sub-obj. 3.b. Determine biogeochemical dynamics of soil C and N including N2O flux as influenced by agroecosystem drivers (e.g. soil, topography, micro-climate, organisms, management). Objective 4. Develop agricultural PM10/PM2.5 and GHG mitigation strategies and management decision aids for Pacific Northwest cropping systems. Sub-obj. 4.a. Determine the effectiveness of alternative tillage and cropping practices in reducing the emission of windblown dust and PM10/PM2.5 from agricultural soils. Sub-obj. 4.b. Develop precision N management practices that increase N use efficiency and decrease N2O emissions. Objective 5: As part of the LTAR network, and in concert with similar long-term, land-based research infrastructure in Inland Pacific Northwest, use the R.J. Cook Agronomy Farm LTAR (CAF) to improve the observational capabilities and data accessibility of the LTAR network, to support research to sustain or enhance agricultural production and environmental quality in agroecosystems characteristic of the Inland Pacific Northwest, as per the LTAR site responsibilities and other information outlined in the 2012 USDA Long- LTAR Network Request for Information (RFI) to which the location successfully responded, and the LTAR Shared Research Strategy, a living document that serves as a roadmap for LTAR implementation. Participation in the LTAR network includes research and data management in support of the ARS GRACEnet and/or Livestock GRACEnet projects.


1b. Approach (from AD-416):
1a. Sediment and PM10/PM2.5 flux, will be evaluated as a function of soil water content/matric potential & crust type/cover/thickness for five major soil types using a portable wind tunnel. Crust type & morphology will be ascertained by microscopy & PLFA & FAME analyses. 1b. Soil aggregate properties will be assessed under a range of crop & tillage systems being examined to control wind-blown dust. Soil aggregate size classes from different crop & tillage systems will be analyzed to identify microbial community composition (PLFA & FAME analyses), active SOM, C source & crushing strength. 1c. Long-term cropping system studies at Lind, Pullman, & Ritzville will be used to assess impacts on soil quality over time including bulk density, soil pH, electrical conductivity, organic C & N, aggregate size distribution, N movement & soil microbial constituents. 2a. Ongoing research will fingerprint soils & PM10 material from across the PNW using FAME. 2b. Bacteria & fungi containing natural markers will also be evaluated as tracers that can be retrieved from soils due to their unique traits of antibiotic resistance or strain-specific molecular markers to determine point source soil movement. 2c. The FAME & bacterial tracer studies will be used to aid corroboration of the Columbia Plateau regional dust transport model by: (1) determining if modeled emissions are from given fields or grid areas; & (2) characterizing the mode of transport from given regions. 3a. Studies are part of GRACEnet (Greenhouse Gas Reduction through C sequestration & Carbon Enhancement Network) & REAP (Renewable Energy Assessment Project), established to assess management impacts on greenhouse gas emissions & soil C status. We will assess tillage & crop rotation affects on soil C storage across variable soil & terrain attributes of the WSU Cook Agronomy Farm (CAF). 3b. Two studies will assess management & environmental effects on soil C and N cycling & GHG emissions. The first study (CAF) was previously described in sub-objective 3a. The second study was established in 2001 at the USDA Palouse Conservation Field Station & consists of five different farming systems including no-till, perennial biofuels, organic, & native perennials. These two field studies will be used to assess soil gas (CO2, N2O) flux, N mineralization-immobilization-turnover & soil C accumulation. 4a. A portable wind tunnel will be used to assess differences in windblown sediment & PM10/PM2.5 emissions among tillage & cropping systems established at various locations across the Columbia Plateau. Wind speed profiles will be measured using pitot tubes, sediment catch obtained using an isokinetic vertical slot sampler, & PM10 concentration profiles obtained using DustTrak aerosol samplers. 4b. Field studies at the CAF will evaluate two N management treatments for winter & spring wheat: (1) site-specific N management based on the spatial pattern of input variables; & (2) uniform N management. N use efficiency will be evaluated to monitor cropping system N use, assess N management strategies & identify key areas for improvements.


3. Progress Report:
Objective 1. Soil quality parameters analyzed for soil and aggregates collected from dryland management practices to determine the impact of management on windblown dust. In addition, analyses of soil organic matter (SOM), soil biology and soil quality were conducted in long-term cropping systems plots. More carbon was found in the larger aggregates than smaller aggregates. Beneficial changes in soil quality occur with less tillage and moderately diverse cropping systems. Objective 2. Land Management and Water Conservation (LMWC) scientists in Pullman, Washington, are characterizing soil microbial communities in soil and PM10 material at locations across the western U.S. to understand dust emissions. ARS scientists in Pullman, Washington, also worked on improving fingerprint methodology by applying micro-organisms to soil as tracers that could provide a powerful tool for understanding dust emission source and fate. Soil containing marked strains of bacteria (tracer organisms) created a unique fingerprint that was identified and traced using microbial analyses. Microbial communities assist in identifying source of windblown dust and assessing soil quality changes with management. Objective 3. Data analysis and preliminary manuscripts completed for field studies that assess topography, micro-climate, crop rotation and tillage management effects on soil C sequestration rates and N cycling. Long-term cropping system studies were identified and monitored for C and N dynamics including greenhouse gas (GHG) flux to: understand and measure emissions of GHG’s from agriculture; and develop improved technologies and practices to manage emissions. A static chamber study with automated GHG flux measurements was successfully field- deployed with different water and N treatments. Objective 4. ARS scientists completed analyses of PM10 emissions data collected from an oilseed cropping system study in 2011 and 2012. Data were collected at two locations where camelina and safflower were grown in rotation with wheat. The publication resulting from this study will aid in assessing the overall environmental impact of growing oilseed crops in the Columbia Plateau. Soil was collected and soil quality parameters analyzed from alternative tillage practices to determine the effectiveness of practices in reducing potential emissions of windblown dust from agricultural soils. Microbial communities assisted in assessing soil quality changes with tillage management. Spatial analyses of field studies at the Washington State University (WSU) Wilke Farm near Davenport, Washington, and the WSU Cook Agronomy Farm were completed and a new crop performance assessment developed. Preliminary results show that N use efficiency can be significantly increased by targeting wheat stand density and N fertilizer rates to specific field locations.


4. Accomplishments
1. Rapid decomposition of canola residue increases the hazard for soil erosion. Growers are adding canola to their cereal-based rotations to diversify cropping systems, break cereal disease cycles, reduce grass weed infestations, and improve water infiltration; however, canola produces less residue that decomposes more rapidly than wheat and degradation of soil quality is a concern. ARS Land Management and Water Conservation Management scientists in Pullman, Washington, found that winter canola had lower fiber components, carbon, carbon/nitrogen ratios and higher nitrogen than spring canola. Residue from higher rainfall locations had higher carbon/nitrogen ratios. Winter canola residue grown in low rainfall zones decomposed rapidly, leaving minimal soil cover. Information on residue decomposition is useful to growers who wish to incorporate canola into their management practices. Additionally, this information can be used so that canola residue can be managed for economic and soil quality benefits in both conventional and conservation farming systems by producers, consultants and land managers.

2. Oilseed cropping systems increase windblown dust emissions. Incorporating oilseeds into conventional dryland wheat-fallow crop rotations is of interest for enhancing biofuel production in the Pacific Northwest. Little is known, however, about the environmental impacts of growing oilseeds in this crop rotation. In cooperation with Washington State University scientists, ARS scientists from Pullman, Washington, found an increase in the emission of dust from land in summer fallow when oilseeds are grown in wheat-oilseed-fallow rotations. An increase in dust emissions will further deteriorate air quality in the region if farmers are not judicious in protecting the soil from wind erosion when oilseeds are grown in crop rotations. These results will help wheat growers, USDA Natural Resource Conservation Service, Conservation Districts, U.S. Environmental Protection Agency and scientists understand the environmental impacts of incorporating oilseeds into dryland cropping systems.

3. Harvesting cereal residues as biofuel feedstocks will impair soil quality and remove substantial crop nutrients in the Palouse. Cereal residues are considered an important feedstock for future biofuel production. Harvesting residues, however, could lead to serious soil degradation and impaired agroecosystem services. Harvesting wheat straw reduced residue carbon inputs by 46% and resulted in levels below that required to maintain soil organic matter. Soil Conditioning Indices resulting from residue harvest were negative throughout the field managed with conventional tillage, but were positive under no-tillage despite straw harvest. Replacement value for nutrients (nitrogen, phosphorus, potassium, sulfur) removed in harvested straw averaged $14.54 per metric ton for dry straw, and ranged from $14 to $32 per acre within the field. We concluded that substantial trade-offs exist in harvesting straw for biofuel, that trade-offs should be evaluated on a site-specific basis, and that support practices such as crop rotation, reduced tillage and site-specific nutrient management need to be considered if residue harvest is to be sustainable. These results will be useful for wheat growers, USDA Natural Resource Conservation Service, Conservation Districts, U.S. Environmental Protection Agency and scientists in the Palouse for understanding the environmental trade-offs of harvesting cereal residues as a biofuel feedstock.

4. Rapid, non-destructive assessment of wheat nitrogen status achieved with terrestrial laser scanning. Optical remote sensing of crop nitrogen status is developing into a powerful diagnostic tool that can improve nitrogen management decisions. We discovered that terrestrial laser scanning was useful for assessing the nitrogen status of winter wheat as well as quantifying aboveground biomass. We concluded that this technology can provide useful information for improving nitrogen management during early season wheat growth. These results will be useful for wheat growers, agribusiness, USDA Natural Resource Conservation Service, Conservation Districts, U.S. Environmental Protection Agency and scientists for developing more efficient nitrogen management strategies.


Review Publications
Sharratt, B.S., Vaddella, V., Feng, G. 2013. Threshold friction velocity influenced by wetness of soils within the Columbia Plateau. Aeolian Research. 9:175-182.

Cogger, C.G., Bary, A.I., Kennedy, A.C., Fortuna, A. 2013. Long-term crop and soil response to biosolids applications in dryland wheat. Journal of Environmental Quality. 42:1872–1880.

Reese, C., Clay, D., Clay, S., Bich, A.D., Kennedy, A.C., Hansen, S., Moriles, J. 2014. Winter cover crops impact on corn production in semiarid regions. Agronomy Journal. 106:1479–1488.

Skinner, D.Z., Bellinger, B.S., Hansen, J.C., Kennedy, A.C. 2014. Carbohydrate and lipid dynamics in wheat crown tissue in response to mild freeze-thaw treatments. Crop Science. 54:1–8. DOI: 10.2135/cropsci2013.09.0604.

Poole, G.J., Smiley, R.W., Walker, C., Huggins, D.R., Rupp, R., Abatzoglou, J., Garland Campbell, K.A., Paulitz, T.C. 2013. Effect of climate on the distribution of Fusarium species causing crown rot of wheat in the Pacific Northwest of the US. Phytopathology. 103:1130-1140.

Kandel, S.L., Smiley, R.W., Garland Campbell, K.A., Elling, A.A., Abatzoglou, J., Huggins, D.R., Rupp, R., Paulitz, T.C. 2013. Relationship between climatic factors and distribution of Pratylenchus spp. in the dryland wheat production areas of Eastern Washington. Plant Disease. 97:1448-1456.

Sharratt, B.S., Schillinger, W. 2014. Windblown dust potential from oilseed cropping systems in the Pacific Northwest United States. Agronomy Journal. 106:1147-1152.

Sharratt, B.S., Van Pelt, R.S. 2013. Erosion by wind: source, measurement, prediction, and control. In: Jorgensen, S.E., editor. Encyclopedia of Environmental Management. New York, NY: Taylor and Francis Group. p. 1017-1030.

Al-Mulla, Y.A., Huggins, D.R., Stockle, C.O. 2014. Simulation of emergence of winter wheat in response to soil temperature, water potential and planting depth. Transactions of the ASABE. 57(3):1-15.

Huggins, D.R., Kruger, C.E., Painter, K.M., Uberuaga, D.P. 2014. Site-specific trade-offs of harvesting cereal residues as biofuel feedstocks. BioEnergy Research. DOI: 10.1007/s12155-014-9438-4.

Karlen, D.L., Huggins, D.R. 2014. Crop residues. In: Karlen, D.L., editor. Cellulosic Energy Cropping Systems. Hoboken, NJ: John Wiley & Sons. p. 131-148.

Eitel, J.U., Magney, T.S., Vierling, L.S., Brown, T.T., Huggins, D.R. 2014. LiDAR based biomass and crop nitrogen estimates for rapid, non-destructive assessment of wheat nitrogen status. Field Crops Research. 159:21–32.