Progress 09/12/08 to 09/11/13

Outputs
Progress Report Objectives (from AD-416): Objective 1: Identify optimal strategies for incorporating bioenergy crops into irrigated Pacific Northwest Region cropping systems. � Sub-objective 1.A. Evaluate the impacts of harvest of C3 and C4 grass perennial biomass crops and the removal of crop residues on carbon sequestration, nutrient dynamics, and soil quality in irrigated Pacific Northwest crop rotations. � Sub-objective 1.B. Determine the efficacy of co-products from agricultural-based energy production on weed and disease control and soil fertility improvement in irrigated crop production systems. Objective 2. Identify optimal combinations of management practices to lower total production costs while maintaining market quality of irrigated potato-based production systems. � Sub-objective 2.A. Determine the impact of reduced tillage on soil conservation/erosion soil physical properties, the mechanisms controlling carbon and nitrogen cycling, and trace gas (CO2, N2O, CH4) fluxes and C sequestration and the yield and quality response of potato and rotational crops. � Sub-objective 2.B. Evaluate the effects of deficit irrigation practices on potato yield and tuber quality. � Sub-objective 2.C. Validate the ARS Potato Growth Simulation Model for the irrigated inland Pacific Northwest region. Objective 3. Develop ecologically-based management strategies that enhance vegetable yields and soil quality in irrigated organic production systems. � Sub-objective 3.A. Quantify key soil agroecological processes (carbon and nitrogen cycling) and application rates of organic amendments that optimize physiological development (nitrogen capture, plant growth rate) of potato under irrigated organic cropping systems. � Sub-objective 3.B. Integrate hybrids with weed suppressive traits into organic specialty crop production systems. Approach (from AD-416): Long-term sustainability of potato production in the Pacific Northwest will depend not only on balancing the physiological production requirements, but also overcoming additional constraints to system productivity and profitability. Assessing sustainability and the basic interactions among system components are multifaceted tasks that require long-term studies integrating a multidisciplinary approach to understand system constraints and also provide data needed to support evaluation of impacts of specialty crops by system modelers. Improved cropping systems will be developed that reduce erosion, reclaim excess N, build organic matter, and suppress pests and improve soil and environmental quality and economic viability. Application of conservation tillage to specialty cropping systems will be investigated to evaluate improving environmental, biological and economic sustainability. With the expansion of the bioenergy industry in the U.S. and state and regional mandates for biofuel blending have made biofuels a high priority issue for the USDA. The expansion of the biofuel industry on potato and other specialty crop production will be investigated. The projected growth of the ethanol and biodiesel industries in the PNW will produce large quantities of organic- based co-products. These co-products are much greater than what can be utilized locally as a source of animal feed, so alternative value added uses will be investigated. The use of these co-products could be used to offset the high costs of nutritional and pest control requirements of potato and specialty crops. The demand for organic produce continues to expand and is of increasing interest to PNW growers. Managing weeds and providing adequate nutrients are the two major production issues for organic producers. Economical and environmentally friendly solutions are needed for organic producers to increase production efficiency by management of weeds and nutrients. Formerly 5354-21660-001-00D (8.08). This is the final report for this project which has been replaced by 5354- 21660-003-00D, "Enhancing Sustainability of Irrigated Specialty Crops and Biofuel Feedstock Production". Measures of the soil C-sequestration potential of irrigated switchgrass production were completed. A manuscript was submitted and was published in the Soil Science Society America Journal. A field trial evaluating the application of agricultural- based energy co-products (e.g. oil-seed meals, distillers grains, anaerobic digested dairy manures) to reduce the application of synthetic fertilizers has been completed. Final assessments of the soil nutrient, potato quality and efficacy of bioenergy co-products have been completed. Three manuscripts on the use of biochar in soil have been published. Onion field trials for weed suppression have been completed. Mustard meal derived from three S. alba genotypes differing in glucosinolate content were evaluated. Studies of greenhouse gas production in reduced tillage and silage corn production have been completed and two manuscript published. Validation of the SPUDSIM potato growth simulation model for the irrigated inland Pacific Northwest region gas been completed. Organic potato production trials were completed on a certified organic field to evaluate a series of organic fertilizers and bioenergy co-products. Economic assessments were not completed however we are soliciting an agriculture economist from Washington State University to assist in data analysis of the organic potato production studies. Field trials comparing sweet corn hybrid tolerance to weeds under different weed management levels including nonchemical approaches applicable to organic farming have been completed and manuscripts published. Significant Activities that Support Special Target Populations: ARS scientists from Prosser, Washington, hosted two female Hispanic summer interns from Florida International University (FIU), Miami, Florida. ARS scientists from Prosser, Washington, continued to collaborate with two professors from Savannah State University (African American students serving university) Savannah, Georgia; and Heritage University (Native American and Hispanic students serving university), Toppenish, Washington. Accomplishments 01 Soil microbial population response to land conversion. A native shrub�steppe ecosystem converted to a series of irrigated organic agricultural fields was evaluated for biological indicators that signaled changes in soil processes during the initial stages of land conversion. Cultivated fields had greater microbial populations and were more biologically active compared to native sites. Microbial characteristics were influenced more by conversion of the native ecosystem to an irrigated agroecosystem and the addition of compost than by the length of time of cultivation. This research benefits organic growers developing production systems on new farmland and provide them insights on how manage soil microbial populations. 02 N uptake by potato under irrigated organic cropping systems. Organic production systems have been shown to improve soil organic matter and stimulate nutrient cycling through enhancement of the soil microflora. Nitrogen released from each of eleven commercial organic fertilizers and compost amendments averaged 25 lb N/acre from April through August, with minor differences between fertilizers. Petiole P and K were maintained above recommended levels throughout the season. This study provides organic potato growers information on the nutrient availability of a diverse array of commercial organic fertilizers. The fertility value of fertilizers tested was shown to be similar, providing organic potato growers� useful information on fertilizer performance rather than testimonials provided by fertilizer suppliers. 03 Competition between crop and weed plants likely co-occurs in many sweet corn fields. In field studies, two hybrids with different levels of tolerance to weed competition were planted at five seeding levels and grown in the presence and absence of wild proso millet. The crop�s ability to tolerate intraspecific and interspecific competition was additive for time to silk, ear number, ear mass, and gross profit margin to the processor. Hybrids showed differential tolerance to interspcific competition, at the seeding levels tested neither hybrid was consistently more tolerant to intraspecific competition. These studies suggest that greater seeding levels could be utilized by growers to maximize marketable ear number and mass, and gross profit margins to the processor. 04 Weeds lower yield and quality of potatoes left uncontrolled. Three new herbicides were tested in potato to determine potato tolerance and weed control. Pyroxasulfone and saflufenacil applied preemergence alone and in tank mixes with currently labeled herbicides did not injure potatoes. Pyroxasulfone controlled barnyardgrass, hairy nightshade, and redroot pigweed equal to or greater than currently labeled herbicides. Saflufenacil controlled common lambsquarters, hairy nightshade, and redroot pigweed at one of two sites equal to that of currently labeled herbicides. These studies indicate that pyroxasulfone and saflufenacil could be useful herbicides for weed control and management of herbicide resistant weed populations in potatoes.

Impacts
(N/A)

Publications

• Boydston, R.A., Felix, J., Al-Khatib, K. 2012. Preemergence herbicides forpotential use in potato (Solanum tuberosum) production. Weed Technology. 26:731-739.
• Felix, J., Boydston, R.A., Burke, I. 2012. Response of direct-seeded dry bulb onion to simulated glyphosate drift with variable rates and application timings. Weed Technology. 26:747-756.
• Johnson, D., Baker, R., Boydston, R.A. 2012. Field evaluation of mint mutant and hybrid lines for resistance to Verticillium wilt and yield. Crop Protection. 43:1-6.
• St�ckle, C., Higgins, S., Kamanian, A., Nelson, R., Huggins, D.R., Marcos, J., Collins, H.P. 2012. Carbon storage and nitrous oxide emissions of cropping systems in eastern Washington: A simulation study. Journal of Soil and Water Conservation. 67(5):365-377.
• Venterea, R.T., Halvorson, A.D., Kitchen, N.R., Liebig, M.A., Cavigelli, M. A., Del Grosso, S.J., Motavalli, P.P., Nelson, K.A., Spokas, K.A., Singh, B.P., Stewart, C.E., Ranaivoson, A., Strock, J., Collins, H.P. 2012. Challenges and opportunities for mitigating nitrous oxide emissions from fertilized cropping systems. Frontiers in Ecology and the Environment. 10(10)562-570.
• Watrud, L., Reichman, J., Bollman, M., Smith, B., Lee, E., Jastrow, J., Casler, M.D., Collins, H.P., Fransen, S., Mitchell, R., Owens, V.N., Bean, B., Rooney, W.L., Tyler, D.D., King, G.A. 2012. Chemistry and microbial functional diversity differences in biofuel crop and grassland soils in multiple geographies. BioEnergy Research. 6(2):601-619.
• Spokas, K.A., Cantrell, K.B., Novak, J.M., Archer, D.W., Ippolito, J.A., Collins, H.P., Boateng, A.A., Lima, I.M., Lamb, M.C., Mcaloon, A.J., Lentz, R.D., Nichols, K.A. 2012. Biochar: A synthesis of its agronomic impact beyond carbon sequestration. Journal of Environmental Quality. 41(4):973- 989.
• Wang, K., Zhu, Z., Haung, H., Li, T., He, Z., Yang, X., Alva, A.K. 2012. Interactive effects of Cd and PAHs on contaminants removal from co- contaminated soil planted with hyperaccumulator plant Sedum alfredii. Journal of Soils and Sediments. 12:556-564.
• Seefeldt, S., Boydston, R.A., Kaspari, P.N., Zhang, M., Carr, E. 2013. Aminopyralid residue impacts on potatoes and weeds. American Journal of Potato Research. 90:239-244.
• Collins, H.P., Porter, L., Streubel, J., Chaves-Cordoba, B. 2013. Phosphorous uptake by potato (Solanum tuberosum L.) from biochar amended with anaerobic digested dairy manure effluent. Agronomy Journal. 105:989- 998.
• El-Kader, A., Hussein, M., Alva, A.K. 2012. Response of jatropha on a clay soil to different concentrations of micronutrients. American Journal of Plant Sciences. 3:1376-1381.
• Wang, K., Huang, H., Zhu, Z., Li, T., He, Z., Yang, X., Alva, A.K. 2013. Phytoextraction of metals and rhizoremediation of PAHs in co-contaminated soil by co-planting of Sedum alfredii with ryegrass (Lolium perenne) or castor (Ricinus communis). International Journal of Phytoremediation. 15:283-298.
• Wang, K., Zhang, J., Zhu, Z., Huang, H., Li, T., He, Z., Yang, X., Alva, A. K. 2013. Pig manure vermicompost (PMVC) can improve phytoremediation of Cd and PAHs co-contaminated soil by Sedum alfredii. Journal of Soils and Sediments. 12:1089-1099.
• Williams, M.M. II, Boydston, R.A. 2013. Intraspecific and interspecific competition in sweet corn. Agronomy Journal. 105(2):503-508.
• Williams, M.M. II, Boydston, R.A. 2013. Crop seeding level: implications for weed management in sweet corn. Weed Science. 61(3):437-442.
• Zhu, Z., Yang, X., Wang, K., Huang, H., Zhang, X., Fang, H., Li, T., Alva, A.K., He, Z. 2012. Bioremediation of Cd-DDT co-contaminated soil using the Cd-hyperaccumulator Sedum alfredii and DDT-degrading microbes. Journal of Hazardous Materials. 235:144-151.
• An, Z., Li, C., Zhang, L., Alva, A.K. 2012. Role of polyamines and phospholipase D in maize (Zea mays L.) response to drought stress. South African Journal of Botany. 83:145-150.
• Cochran, R.L., Collins, H.P., Alva, A.K. 2013. Response of selected soil microbial populations and activities to land conversion. Communications in Soil Science and Plant Analysis. 44:1976-1991.

Progress 10/01/11 to 09/30/12

Outputs
Progress Report Objectives (from AD-416): Objective 1: Identify optimal strategies for incorporating bioenergy crops into irrigated Pacific Northwest Region cropping systems. � Sub-objective 1.A. Evaluate the impacts of harvest of C3 and C4 grass perennial biomass crops and the removal of crop residues on carbon sequestration, nutrient dynamics, and soil quality in irrigated Pacific Northwest crop rotations. � Sub-objective 1.B. Determine the efficacy of co-products from agricultural-based energy production on weed and disease control and soil fertility improvement in irrigated crop production systems. Objective 2. Identify optimal combinations of management practices to lower total production costs while maintaining market quality of irrigated potato-based production systems. � Sub-objective 2.A. Determine the impact of reduced tillage on soil conservation/erosion soil physical properties, the mechanisms controlling carbon and nitrogen cycling, and trace gas (CO2, N2O, CH4) fluxes and C sequestration and the yield and quality response of potato and rotational crops. � Sub-objective 2.B. Evaluate the effects of deficit irrigation practices on potato yield and tuber quality. � Sub-objective 2.C. Validate the ARS Potato Growth Simulation Model for the irrigated inland Pacific Northwest region. Objective 3. Develop ecologically-based management strategies that enhance vegetable yields and soil quality in irrigated organic production systems. � Sub-objective 3.A. Quantify key soil agroecological processes (carbon and nitrogen cycling) and application rates of organic amendments that optimize physiological development (nitrogen capture, plant growth rate) of potato under irrigated organic cropping systems. � Sub-objective 3.B. Integrate hybrids with weed suppressive traits into organic specialty crop production systems. Approach (from AD-416): Long-term sustainability of potato production in the Pacific Northwest will depend not only on balancing the physiological production requirements, but also overcoming additional constraints to system productivity and profitability. Assessing sustainability and the basic interactions among system components are multifaceted tasks that require long-term studies integrating a multidisciplinary approach to understand system constraints and also provide data needed to support evaluation of impacts of specialty crops by system modelers. Improved cropping systems will be developed that reduce erosion, reclaim excess N, build organic matter, and suppress pests and improve soil and environmental quality and economic viability. Application of conservation tillage to specialty cropping systems will be investigated to evaluate improving environmental, biological and economic sustainability. With the expansion of the bioenergy industry in the U.S. and state and regional mandates for biofuel blending, have made biofuels a high priority issue for the USDA. The expansion of the biofuel industry on potato and other specialty crop production will be investigated. The projected growth of the ethanol and biodiesel industries in the PNW will produce large quantities of organic- based co-products. These co-products are much greater than what can be utilized locally as a source of animal feed, so alternative value added uses will be investigated. The use of these co-products could be used to offset the high costs of nutritional and pest control requirements of potato and specialty crops. The demand for organic produce continues to expand and is of increasing interest to PNW growers. Managing weeds and providing adequate nutrients are the two major production issues for organic producers. Economical and environmentally friendly solutions are needed for organic producers to increase production efficiency by management of weeds and nutrients. Measures of the soil C-sequestration potential of irrigated switchgrass production were completed. A manuscript was submitted and was published in the Soil Science Society America Journal. A field trial established in 2008 evaluating the application of agricultural-based energy co-products (e.g. oil-seed meals, distillers grains, anaerobic digested dairy manures) to reduce the application of synthetic fertilizers has been completed. Final assessments of the soil nutrient, potato quality and efficacy of bioenergy co-products are being analyzed. Three manuscripts on the use of biochar in soil have been published. Onion field trials for weed suppression have been completed. Mustard meal derived from three S. alba genotypes differing in glucosinolate content were evaluated. Studies of greenhouse gas production in reduced tillage and sillage corn production have been completed and two manuscript published. Validation of the SPUDSIM potato growth simulation model for the irrigated inland Pacific Northwest region gas been completed. Second year potato trials were established on a certified organic field to evaluate a series of organic fertilizers and bioenergy coproducts. Manuscript being prepared on two year field trial comparing sweet corn hybrid tolerance to weeds under different weed management levels including nonchemical approaches applicable to organic farming. Significant Activities that Support Special Target Populations: On January 26, 2012 USDA-ARS soil scientists/microbiologists from ARS Vegetable and Forage Crops Research Unit (VFCRU), Prosser, WA, presented talks at the 2012 Yakama Nation and U.S Bureau of Indian Affairs: Controlling Agricultural Leakage by Optimizing Input Efficiency; a Sustainable Agriculture Workshop. The talks described methods and technologies to increase and improve soil fertility, water use and the quality of soil organic matter. The annual meeting was attended by 25 farmers, crop consultants and researchers from throughout the Yakima Valley and Columbia Basin of Washington and covers a wide variety of specialty crop production issues. Accomplishments 01 Greenhouse gas emissions from soil amended with anaerobic digested dairy manure. Dairy production in the Pacific Northwest has grown steadily ov the past decade resulting in large concentrations of animal wastes. Thes wastes have been implicated in the decline of surface and subsurface wat quality as well as an increase in the production of greenhouse gases whe used as a soil amendment. Field studies showed that emission rates of greenhouse gases (GHG) were significantly less (60%) than the emission value proposed by the International Panel on Climate Change (IPCC). 02 Biochar amended with dairy effluent maintains recommended phosphorus levels. We demonstrated that biochar amended with dairy effluent applie at 2.5 Ton/acre maintained recommended soluble P levels (1000 ppm) in Ranger and Umatilla potato variety petioles through 60 days after emergence. Biochar additions improve soil pH, water holding capacity and soil C pools. Removal of nutrients by biochar from dairy storage lagoons and used as a supplemental fertilizer off site is a beneficial strategy reduce nutrient contamination around dairies and supply nutrients for potato production. 03 Biochar added to soil reduces bioavailability of atrazine and metribuzin We demonstrated that biochar added to two soils reduced the bioavailability of both atrazine and metribuzin. Reduction in herbicidal activity was the result of increased sorption of both herbicides by biochar. This information also allows producers to adjust herbicide rate to counter the reduction in herbicide activity when electing to amend so with biochar. 04 Identifying herbicide resistant weeds. Weed seed were collected from escape weeds in potato fields throughout the Columbia Basin and were tested for dose response to metribuzin. Fifteen of 27 pigweed biotypes a 8 of 25 common lambsquarters biotypes were resistant to metribuzin rangi from 2 to 142 fold more herbicide required to provide 90% control compar to the susceptible biotype. This information provides producers with knowledge to improve herbicide selection and weed management practices that delay, prevent, and manage herbicide resistant weeds. 05 Minor yield losses in potato using deficit irrigation. Cost of potato irrigation in the Columbia basin is approximately 10% of total cost of production. Yield reduction in Ranger Russet and Umatilla Russet cultiva was 7 to 10% with 14 to 17% deficit irrigation as compared to the yield with irrigation to replenish full evapotranspiration. Major yield loss with deficit irrigation was associated with reduction of >8 oz size tube 06 Polymer coated fertilizers reduce N fertilizer rates. Pre-plant application of 200 lbs N/acre as polymer coated urea PCU, (Complete or 50/50 mix of PCU/urea) produced similar tuber yield (about 35 tons/acre) of Umatilla Russet cultivar as compared to that with conventional fertilization practices of 300 lbs N/acre, i.e. 100 lbs N/acre urea pre- plant and five fertigations of UAN at 200 lbs N/acre. 07 Low frequency fertigations (application of fertilizer) more efficient th high frequency. Under conventional nitrogen management for potatoes in the lower Columbia Basin, the optimal N management is 100 lbs N/acre as urea pre-plant soil applied plus 200 lbs N/acre in five fertigations as UAN at two weeks interval, four weeks after seedling emergence. Increase frequency of in-season fertilization (i.e. 10 or 20) failed to provide a additional benefits.

Impacts
(N/A)

Publications

• Wang, Q., Li, Y.C., Klassen, W., Alva, A.K. 2011. High retention of N P nutrients, soil organic carbon, and fine particles by cover crops under tropical climate. Agronomy for Sustainable Development. DOI: 10. 1007/S13593-011-0054-9.
• Lange, B., Mahmoud, S., Wildung, M., Turner, G., Davis, I., Baker, R., Boydston, R.A., Croteau, R. 2011. Improving peppermint essential oil yield and composition by metabolic engineering. Proceedings of the National Academy of Sciences. 41:16944-16949.
• Felix, J., Boydston, R.A. 2011. Potato (Solanum tuberosum) response to simulated glyphosate drift. Weed Technology. 25:637-644.
• Alva, A.K., Moore, A.D., Collins, H.P. 2012. Impact of deficit irrigation on tuber yield and quality of potato cultivars. Journal of Crop Improvement. 26:211-227.
• Alva, A.K., Ren, H., Moore, A.D. 2012. Water and nitrogen management effects on biomass accumulation and partitioning in two potato cultivars. American Journal of Plant Sciences. 3:164-170.
• Wang, S.S., Alva, A.K., Li, Y.C., Zhang, M. 2011. A rapid technique for prediction of nutrient release from controlled release fertilizers. Open Journal of Soil Science. 1:40-44.
• Liu, G., Li, Y., Alva, A.K., Porterfield, D.M., Dunlop, J. 2012. Enhancing nitrogen use efficiency of cereal crops by optimizing temperature, moisture, balanced nutrients, and oxygen bioavailability. Journal of Plant Nutrition. 35:428-441.
• Awad, M., Abd El-Kader, A.A., Attia, M., Alva, A.K. 2011. Effects of nitrogen fertilization and soil inoculation of sulfur oxidizing or nitrogen fixing bacteria on onion plant growth and yield. International Journal of Agronomy. DOI: 10.1155/2011/316856.
• Han, M.Y., Zhang, L.X., Fan, C.H., Liu, L.H., Zhang, L.S., Li, B.Z., Alva, A.K. 2011. Release of nitrogen, phosphorus, and potassium during the decomposition of apple (Malus domestica) leaf litter under different fertilization regimes. Soil Science and Plant Nutrition (SSPN). 57:549-557. DOI: 10.1080/00380768.211.593481.
• Hussien, M.M., El-Faham, S.Y., Alva, A.K. 2012. Pepper plants growth, yield, photosynthetic pigments, and total phenols as affected by foliar application of potassium under different salinity irrigation water. Agricultural Sciences. 3;241-248.
• Streubel, J.D., Collins, H.P., Tarara, J.M., Cochran, R.L. 2012. Biochar produced from anaerobically-digested fiber reduces phosphorus in dairy lagoons. Journal of Environmental Quality. 41:1166-1174.
• Collins, H.P., Streubel, J., Alva, A.K., Frear, C., Chen, S., Fransen, S.F. , Kruger, C., Granatstein, D. 2011. Greenhouse gas emissions from an irrigated silt loam soil amended with anaerobic digested dairy manure. Soil Science Society of America Journal. 75:2206-2216.

Progress 10/01/10 to 09/30/11

Outputs
Progress Report Objectives (from AD-416) Objective 1: Identify optimal strategies for incorporating bioenergy crops into irrigated Pacific Northwest Region cropping systems. � Sub-objective 1.A. Evaluate the impacts of harvest of C3 and C4 grass perennial biomass crops and the removal of crop residues on carbon sequestration, nutrient dynamics, and soil quality in irrigated Pacific Northwest crop rotations. � Sub-objective 1.B. Determine the efficacy of co-products from agricultural-based energy production on weed and disease control and soil fertility improvement in irrigated crop production systems. Objective 2. Identify optimal combinations of management practices to lower total production costs while maintaining market quality of irrigated potato-based production systems. � Sub-objective 2.A. Determine the impact of reduced tillage on soil conservation/erosion soil physical properties, the mechanisms controlling carbon and nitrogen cycling, and trace gas (CO2, N2O, CH4) fluxes and C sequestration and the yield and quality response of potato and rotational crops. � Sub-objective 2.B. Evaluate the effects of deficit irrigation practices on potato yield and tuber quality. � Sub-objective 2.C. Validate the ARS Potato Growth Simulation Model for the irrigated inland Pacific Northwest region. Objective 3. Develop ecologically-based management strategies that enhance vegetable yields and soil quality in irrigated organic production systems. � Sub-objective 3.A. Quantify key soil agroecological processes (carbon and nitrogen cycling) and application rates of organic amendments that optimize physiological development (nitrogen capture, plant growth rate) of potato under irrigated organic cropping systems. � Sub-objective 3.B. Integrate hybrids with weed suppressive traits into organic specialty crop production systems. Approach (from AD-416) Long-term sustainability of potato production in the Pacific Northwest will depend not only on balancing the physiological production requirements, but also overcoming additional constraints to system productivity and profitability. Assessing sustainability and the basic interactions among system components are multifaceted tasks that require long-term studies integrating a multidisciplinary approach to understand system constraints and also provide data needed to support evaluation of impacts of specialty crops by system modelers. Improved cropping systems will be developed that reduce erosion, reclaim excess N, build organic matter, and suppress pests and improve soil and environmental quality and economic viability. Application of conservation tillage to specialty cropping systems will be investigated to evaluate improving environmental, biological and economic sustainability. With the expansion of the bioenergy industry in the U.S. and state and regional mandates for biofuel blending have made biofuels a high priority issue for the USDA. The expansion of the biofuel industry on potato and other specialty crop production will be investigated. The projected growth of the ethanol and biodiesel industries in the PNW will produce large quantities of organic- based co-products. These co-products are much greater than what can be utilized locally as a source of animal feed, so alternative value added uses will be investigated. The use of these co-products could be used to offset the high costs of nutritional and pest control requirements of potato and specialty crops. The demand for organic produce continues to expand and is of increasing interest to PNW growers. Managing weeds and providing adequate nutrients are the two major production issues for organic producers. Economical and environmentally friendly solutions are needed for organic producers to increase production efficiency by management of weeds and nutrients. Formerly 5354-21660-001-00D (8.08). NP 216. Objective (1) Identify optimal strategies for incorporating bioenergy crops into irrigated Pacific Northwest Region cropping systems. Sub-objective 1.A. Evaluate the impacts of harvest of grass perennial biomass crops and crop residues on carbon sequestration, nutrient dynamics, and soil quality. Measures of C-sequestration potential by laboratory incubations and 13C analyses were completed for the study. A manuscript was submitted and was published in the Soil Science Society America Journal. Sub-objective 1.B. Determine the efficacy of co-products from agricultural-based energy production on soil fertility improvement in irrigated crop production systems. The field trial established in 2008 evaluating the application of agricultural-based energy co-products (e.g. oil-seed meals, distillers grains, anaerobic digested dairy manures) to reduce the application of synthetic fertilizers has been completed. Final third year assessments of the soil nutrient, potato quality and efficacy of bioenergy co-products are being analyzed. Two manuscripts on the use of biochar in soil have been submitted and accepted. 1B1. Onion field trials for weed suppression have been completed. Mustard meal derived from three S. alba genotypes differing in glucosinolate content were evaluated. Manuscript submitted and accepted to Weed Science titled �Onion and weed response to mustard (Sinapis alba) seed meal�. Objective 2. Identify optimal combinations of management practices to lower total production costs while maintaining market quality of irrigated potato- based production systems. This study is a continuation of the previous research project. Sub-objective 2.A. Determine the impact of reduced tillage on soil conservation, soil physical properties, and the yield and quality response of potato and rotational crops. Completed measurements of wind erosion and dust (i.e. PM10) emissions under the reduced and conventional tillage and crop. Sub-objective 2.B. The studies of greenhouse gas production have been completed and peer-reviewed manuscript published. Two manuscripts were submitted and accepted. Sub- objective 2.C. Evaluate the effects of deficit irrigation practices on potato yield and tuber quality. The field research has been completed and analysis of data from the field trials are completed. Sub-objective 2.D. Validate potato growth simulation model for the irrigated inland Pacific Northwest region. The SPUDSIM Simulation Model is being developed by the ARS-Crop Systems and Global Change Laboratory, Beltsville, MD. Sub- objective 3.A. Quantify key soil agroecological processes and application rates of organic amendments under irrigated organic potato production. Potato trials were established on a certified organic field has to evaluate a series of organic fertilizers and bioenergy coproducts. Sub- objective 3.B. Integrate sweet corn hybrids with weed suppressive traits into organic specialty crop production. Began data analysis on two year field trial comparing sweet corn hybrid tolerance to weeds under different weed management levels. Significant Activities that Support Special Target Populations On June 16th 2011 the soil scientist/microbiologist at the ARS Vegetable and Forage Crops Research Unit (VFCRU), Prosser, WA, presented a talk at an organic field day held on an organic farm in the Columbia Basin. The talk described methods and technologies to increase and improve soil fertility and the quality of soil organic matter using a variety of organic amendments. The field day was attended by 25 organic vegetable brokers from the Western U.S. (California, Oregon, Washington, Colorado, Idaho) Accomplishments 01 Remediation of phosphorus from dairy lagoon waters using biochar. Estimates of animal manures produced in the United States by feedlot cattle, dairy cattle and swine exceeds 78 million tons annually. ARS scientists in Prosser, WA, have developed an approach to utilize dairy waste as an alternative energy and fertilizer source. The fiber componen exiting a GHD Plugged Flow anaerobic was used to produce bio-gas or bio- oil under low temperature pyrolysis. The co-product, biochar was applied to dairy waste water to remove nutrients. Our approach resulted in the removal of >32% of the P from the dairy effluent within 15 days of treatment. The current price of biochar is $200-300 per ton. Dairies in Washington State could produce 230,000 tons of biochar a year from manur 02 Mustard seed meals effective weed control in onions. Weed management represents the major cost of production for organic onions and hand weeding can cost up to $2,000 per acre. Alternative methods of weed control that reduce the amount of hand weeding are needed. ARS scientist in Prosser, WA, identified the herbicidal compounds in mustard (Sinapis alba) meal and refined the use patterns of mustard meal to obtain weed suppression without harming the onion crop. We demonstrated that mustard seed meals that contain high levels of sinalbin suppressed weeds when applied after the two leaf stage of onions and significantly reduced the amount of hand weeding required in trials conducted over three years on commercial organic fields. The use of mustard seed meal may be useful to producers of organic crops for weed suppression and help reduce excessiv costs of hand weeding which can range from $500 to $2,000 per acre.

Impacts
(N/A)

Publications

• Felix, J., Boydston, R.A. 2010. Evaluation of Imazosulfuron for Yellow Nutsedge (Cyperus esculentus) and Broadleaf Weed Control in Potato. Weed Technology. 24:4 471-477.
• Alva, A.K., Fan, M., Qing, C., Rosen, C., Ren, H. 2011. Improving Nutrient- use Efficiency in Chinese Potato Production - Experiences From the USA. Journal of Crop Improvement. 25:46-85.
• Fan, X.H., Li, Y.C., Alva, A.K. 2011. Effects of Temperature and Soil Type on Ammonia Volatilization from Slow-Release Nitrogen Fertilizers. Communications in Soil Science and Plant Analysis. 42:10, 1111-1122.
• Hussein, M.M., Abd El-Kader, A.A., Kady, K.A., Youssef, R.A., Alva, A.K. 2010. Sorghum Response to Foliar Application of Phosphorus and Potassium with Saline Water Irrigation. Journal of Crop Improvement. 24:324-336.
• Wang, Q., Li, Y., Alva, A.K. 2010. Cropping Systems to Improve Carbon Sequesteration for Mitigation of Climate Change. Journal of Environmental Protection. 1:207-215.
• Boydston, R.A. 2010. Managing Weeds in Potato Rotations without Herbicides. American Journal of Potato Research. 87:420-427.
• Boydston, R.A., Collins, H.P., Fransen, S. 2010. Response of Three Switchgrass (Panicum virgatum) Cultivars to Mesotrione, Quinclorac, and Pendimethalin. Weed Technology. 24:336-341.
• Alva, A.K., Sajwan, K., Paramasivam, S. 2011. Effects of water treatment residuals and coal combustion byproduct amendments on properties of a sandy soil and impact on crop production � A pot experiment. Archives of Agronomy and Soil Science. 2011:1-10.
• Liu, G.D., Li, Y.C., Migliaccio, K.W., Ouyang, Y., Alva, A.K. 2011. Identification of Factors Most Important for Ammonia Emission from Fertilized Soils for Potato Production Using Principle Component Analysis. Journal of Sustainable Watershed Science & Management. 1:21-30.
• Collins, H.P., Fransen, S., Smith, J.L. 2010. Carbon sequestration under irrigated switchgrass (panicum virgatum) production. Soil Science Society of America Journal. 74:2049-2058.
• Williams, M.M. II, Boydston, R.A., Peachey, R.E., Robinson, D. 2011. Performance consistency of reduced Atrazine use in sweet corn. Field Crops Research. 121:96-104.
• Smith, J.L., Collins, H.P., Bailey, V.L. 2010. The effect of young biochar on soil respiration. Soil Biology and Biochemistry. 42(12):2345-2347. doi:10.1016/j.soilbio.2010.09.013.
• Calderon, F.J., Reeves III, J.B., Collins, H.P., Eldor, P.A. 2011. Chemical differences in soil organic matter fractions determined by diffuse-reflectance mid-infrared spectroscopy. Soil Science Society of America Journal. 75(2)568-579.
• Collins, D.P., Cogger, C.G., Kennedy, A.C., Forge, T., Collins, H.P., Bary, A.I., Rossi, R. 2011. Farm-scale variation of soil quality indices and association with edaphic properties. Soil Science Society of America Journal. 75:580�590. doi:10.2136/sssaj2010.0029.
• Streubel, J.D., Collins, H.P., Garcia-Perez, M., Tarara, J.M., Granatstein, D., Kruger, C.E. 2011. Influence of Biochar on Soil pH, Water Holding Capacity, Nitrogen and Carbon Dynamics. Soil Science Society of America Journal. 75: 1402-1413.

Progress 10/01/09 to 09/30/10

Outputs
Progress Report Objectives (from AD-416) Objective 1: Identify optimal strategies for incorporating bioenergy crops into irrigated Pacific Northwest Region cropping systems. � Sub-objective 1.A. Evaluate the impacts of harvest of C3 and C4 grass perennial biomass crops and the removal of crop residues on carbon sequestration, nutrient dynamics, and soil quality in irrigated Pacific Northwest crop rotations. � Sub-objective 1.B. Determine the efficacy of co-products from agricultural-based energy production on weed and disease control and soil fertility improvement in irrigated crop production systems. Objective 2. Identify optimal combinations of management practices to lower total production costs while maintaining market quality of irrigated potato-based production systems. � Sub-objective 2.A. Determine the impact of reduced tillage on soil conservation/erosion soil physical properties, the mechanisms controlling carbon and nitrogen cycling, and trace gas (CO2, N2O, CH4) fluxes and C sequestration and the yield and quality response of potato and rotational crops. � Sub-objective 2.B. Evaluate the effects of deficit irrigation practices on potato yield and tuber quality. � Sub-objective 2.C. Validate the ARS Potato Growth Simulation Model for the irrigated inland Pacific Northwest region. Objective 3. Develop ecologically-based management strategies that enhance vegetable yields and soil quality in irrigated organic production systems. � Sub-objective 3.A. Quantify key soil agroecological processes (carbon and nitrogen cycling) and application rates of organic amendments that optimize physiological development (nitrogen capture, plant growth rate) of potato under irrigated organic cropping systems. � Sub-objective 3.B. Integrate hybrids with weed suppressive traits into organic specialty crop production systems. Approach (from AD-416) Long-term sustainability of potato production in the Pacific Northwest will depend not only on balancing the physiological production requirements, but also overcoming additional constraints to system productivity and profitability. Assessing sustainability and the basic interactions among system components are multifaceted tasks that require long-term studies integrating a multidisciplinary approach to understand system constraints and also provide data needed to support evaluation of impacts of specialty crops by system modelers. Improved cropping systems will be developed that reduce erosion, reclaim excess N, build organic matter, and suppress pests and improve soil and environmental quality and economic viability. Application of conservation tillage to specialty cropping systems will be investigated to evaluate improving environmental, biological and economic sustainability. With the expansion of the bioenergy industry in the U.S. and state and regional mandates for biofuel blending have made biofuels a high priority issue for the USDA. The expansion of the biofuel industry on potato and other specialty crop production will be investigated. The projected growth of the ethanol and biodiesel industries in the PNW will produce large quantities of organic- based co-products. These co-products are much greater than what can be utilized locally as a source of animal feed, so alternative value added uses will be investigated. The use of these co-products could be used to offset the high costs of nutritional and pest control requirements of potato and specialty crops. The demand for organic produce continues to expand and is of increasing interest to PNW growers. Managing weeds and providing adequate nutrients are the two major production issues for organic producers. Economical and environmentally friendly solutions are needed for organic producers to increase production efficiency by management of weeds and nutrients. Formerly 5354-21660-001-00D (8.08). Measurements of above- and below-ground productivity, nutrient export, and C sequestration were made using a combination of field and laboratory studies. Measures of C-sequestration potential by laboratory incubations and 13C analyses were completed for both 2008 and 2009 soil samplings. A field trial evaluating the application of agricultural-based energy co- products (e.g. oil-seed meals, distillers grains, anaerobic digested dairy manures) to reduce the application of synthetic fertilizers was established at the USDA-ARS Field Station in Paterson WA. Second year assessments of the soil nutrient, potato quality and efficacy of each bioenergy co-products are being analyzed. Field trials evaluating weed suppression in organic onions with Sinapis alba seed meal were completed. Sweet corn hybrids differing in weed tolerance and weed suppressive ability are being evaluated among two levels of cultivation in a second year field trial. The influence of biochar on herbicide activity of atrazine and metribuzin was tested using greenhouse oat bioassays. Completed measurements of wind erosion and dust (i.e. PM10) emissions under the reduced and conventional tillage and crop. The studies of greenhouse gas production have been completed and peer-reviewed manuscript published. The field research on the effects of deficit irrigation practices on potato yield and tuber quality has been completed and analyses of data from the field trials are in progress. Potato and corn field experiments under different nutrient management are in progress. Plant samplings are taken at various growth stages for measurement of biomass and nutrients accumulation and partitioning. These data will be used for field validation of crop simulation models. Significant Activities that Support Special Target Populations Presented a talk at the 2010 Yakama Nation: Roots for Productivity Workshop in Toppenish, WA. The talk described methods and technologies to increase and improve soil fertility and the quality of soil organic matter. The annual meeting was attended by 60 farmers, crop consultants and researchers from throughout the Yakima Valley and Columbia Basin of Washington and covers a wide variety of specialty crop production issues. Accomplishments 01 Biochar Research. Biochar is being promoted for its potential to improv soil properties, fertility and carbon sequestration in soil. How this material might impact agricultural soils within temperate regions is largely unknown. Validation of biochar as a beneficial soil amendment an carbon sink would add important economic value to the pyrolysis process and spur adoption. ARS researchers from the Vegetable and Forage Crops Research Unit, Prosser, WA evaluated five bio-chars made from five waste feedstocks for their influence on the soil properties and C sequestrati potentials. Biochar was found to increase soil pH, water holding capaci and soil C pools. A 168 pp report was published on line at http://csanr. wsu.edu/CFF/cffpubs.html#biofuel. This information is being requested by local and state economic development agencies as well as growers, consultants and other researchers. 02 Dairy manure as an energy and fertilizer source. The common practice fo disposal of dairy manure is application of lagoon water to adjacent agricultural fields which results in nutrient leaching to groundwater or runoff losses to waterways. ARS scientists at the Vegetable and Forage Crops Research Unit, Prosser, WA developed technology to utilize dairy waste as a source phosphorus fertilizer. The co-product, biochar made fr the pyrolysis of manure was applied to dairy waste water to capture nutrients. The addition of biochar removed 68% of the phosphorus and 14% of the nitrogen from the dairy waste water within 15 days of application Dairies in Washington State could produce 230,000 tons of nutrient enriched biochar a year from manure reducing leaching and runoff losses. 03 Biochar affects the activity of two herbicides. Biochar is being utiliz as a soil amendment in various cropping systems and may impact the activity of herbicides. Researchers at the Vegetable and Forage Crops Production unit in Prosser, Washington found that adding biochar reduced the activity of two common herbicides used in potato and corn production which could result in poor weed control. This information can be utilize by producers to modify herbicide rates and prevent weed control failures when utilizing biochar as a soil amendment. 04 Impact of deficit irrigation on potato production and quality. Potato tuber yield and quality are impacted by irrigation and nitrogen (N) management. Deficit irrigation, meaning a 20% reduction in total amount water applied, resulted in 7-24% tuber yield reduction compared to that the plants received standard irrigation, where daily water loss from the soil and plants is replenished daily. Yield reduction in deficit irrigation was generally attributed to reduction in large weight tubers, >0.227 kg/tuber. This study demonstrated that modest deficit irrigation of only 20% total water applied, can result in significant reduction in net returns under high productive growing conditions in the Northwest. 05 Weed-free Crop Rotation reduces Corky Ringspot. Corky ringspot disease (CRS) of potato is caused by tobacco rattle virus (TRV) and vectored by stubby root nematode and makes tubers unmarketable. CRS is present in approximately 5% of the potato acreage of the Columbia Basin and soil fumigation, costing $200/acre, is currently the only method of control. Researchers at the Vegetable and Forage Crops unit in Prosser, WA completed research demonstrating that growing weed-free alfalfa cleanse CRS from soil. Weed hosts of TRV and stubby root nematode were identifi that when present in the crop rotation, prevented the cleansing of TRV from the nematode population. Growers can utilize this research to eliminate or lesson the need for costly soil fumigation, saving approximately $1.5 million dollars to the industry. 06 Weed control important in the eradication of potato cyst nematode. The potato cyst nematode, Globodera pallida (PCN), a restricted pest in the United States, was first reported in Idaho in 2006 and the U.S. governme and Idaho State Department of Agriculture hope to eradicate it from infested fields. Eradicating PCN will require depriving the nematodes of their hosts (potatoes, tomatoes, and various weeds) over a protracted ti period. The host status of PCN found in Idaho has not been documented an is unknown. Host suitability tests were conducted on common weeds found the PNW potato production region. Reproduction of PCN occurred on hairy nightshade (Solanum physalifolium) biotypes from Idaho and Washington. Cutleaf nightshade (S. triflorum) (biotypes from Idaho and Washington), black nightshade (S. nigrum) (Washington biotype), bittersweet nightshad (S. dulcamara) (Idaho biotype) were relatively poor hosts of PCN. PCN di not produce new cysts on redroot pigweed (Amaranthus retroflexus), kochi (Kochia scoparia), and common lambsquarters (Chenopodium album). Control of hairy nightshade during the eradication of potato cyst nematode from infested fields will increase the likelihood of success.

Impacts
(N/A)

Publications

• Moore, A.D., Alva, A.K., Collins, H.P., Boydston, R.A. 2010. Mineralization of nitrogen from biofuel byproducts and animal manures amended to a sandy soil. Communications in Soil Science and Plant Analysis. 41:1315-1326.
• Paramasivam, S., Richards, K.A., Alva, A.K., Sajwan, K.S., Afolabi, J., Richards, A.M. 2009. Evaluation of Poultry Litter Amendment to Agricultural Soils: Leaching Losses and Partitioning of Trace Elements in Collard Greens. Journal Of Water Air And Soil Pollution. 202: 229-243.
• Alva, A.K., Marcos, J., Stockle, C., Reddy, V., Timlin, D.J. 2010. A Crop Simulation Model for Prediction of Yield and Fate of Nitrogen in Irrigated Potato Rotation Cropping System. Journal of Crop Improvement. 24: 142-152.
• Paramasivam, S., Jayaraman, K., Wilson, T.C., Alva, A.K., Kelson, L., Jones, L.B. 2009. Ammonia Volatilization Loss from Surface Applied Livestock Manure. Journal of Environmental Science and Health. 44: 317-324.
• Wang, Q., Li, Y., Alva, A.K. 2010. Growing Cover Crops Improve Biomass Accumulation and Carbon Sequestration: A Phytotron Study. Journal of Environmental Protection. 1: 73-84.
• Alva, A.K. 2010. Techniques to Enhancing Sustainable Nutrient and Irrigation Management for Potatoes. Journal of Crop Improvement. 24:281- 297.
• Macconnell, C.B., Collins, H.P. 2009. Utilization of Re-processed Anaerobically Digested Fiber from Dairy Manure as a Container Media Substrate. Acta Horticulturae. 819: 279-286.
• Stockle, C.O., Nelson, R.L., Higgins, S., Brunner, J., Grove, G., Boydston, R.A., Whiting, M., Kruger, C. 2010. Assessment of climate change impact on Eastern Washington agriculture. Climatic Change. Available: http://www. springerlink.com/content/q844862577u49121/fulltext.pdf.
• Young, S.L., Pierce, F.J., Streubel, J.D., Collins, H.P. 2009. Performance of solid-state sensors for continuous, real-time measurement of soil CO2 concentrations. Agronomy Journal. 101:1417-1420.

Progress 10/01/08 to 09/30/09

Outputs
Progress Report Objectives (from AD-416) Objective 1: Identify optimal strategies for incorporating bioenergy crops into irrigated Pacific Northwest Region cropping systems. � Sub-objective 1.A. Evaluate the impacts of harvest of C3 and C4 grass perennial biomass crops and the removal of crop residues on carbon sequestration, nutrient dynamics, and soil quality in irrigated Pacific Northwest crop rotations. � Sub-objective 1.B. Determine the efficacy of co-products from agricultural-based energy production on weed and disease control and soil fertility improvement in irrigated crop production systems. Objective 2. Identify optimal combinations of management practices to lower total production costs while maintaining market quality of irrigated potato-based production systems. � Sub-objective 2.A. Determine the impact of reduced tillage on soil conservation/erosion soil physical properties, the mechanisms controlling carbon and nitrogen cycling, and trace gas (CO2, N2O, CH4) fluxes and C sequestration and the yield and quality response of potato and rotational crops. � Sub-objective 2.B. Evaluate the effects of deficit irrigation practices on potato yield and tuber quality. � Sub-objective 2.C. Validate the ARS Potato Growth Simulation Model for the irrigated inland Pacific Northwest region. Objective 3. Develop ecologically-based management strategies that enhance vegetable yields and soil quality in irrigated organic production systems. � Sub-objective 3.A. Quantify key soil agroecological processes (carbon and nitrogen cycling) and application rates of organic amendments that optimize physiological development (nitrogen capture, plant growth rate) of potato under irrigated organic cropping systems. � Sub-objective 3.B. Integrate hybrids with weed suppressive traits into organic specialty crop production systems. Approach (from AD-416) Long-term sustainability of potato production in the Pacific Northwest will depend not only on balancing the physiological production requirements, but also overcoming additional constraints to system productivity and profitability. Assessing sustainability and the basic interactions among system components are multifaceted tasks that require long-term studies integrating a multidisciplinary approach to understand system constraints and also provide data needed to support evaluation of impacts of specialty crops by system modelers. Improved cropping systems will be developed that reduce erosion, reclaim excess N, build organic matter, and suppress pests and improve soil and environmental quality and economic viability. Application of conservation tillage to specialty cropping systems will be investigated to evaluate improving environmental, biological and economic sustainability. With the expansion of the bioenergy industry in the U.S. and state and regional mandates for biofuel blending have made biofuels a high priority issue for the USDA. The expansion of the biofuel industry on potato and other specialty crop production will be investigated. The projected growth of the ethanol and biodiesel industries in the PNW will produce large quantities of organic- based co-products. These co-products are much greater than what can be utilized locally as a source of animal feed, so alternative value added uses will be investigated. The use of these co-products could be used to offset the high costs of nutritional and pest control requirements of potato and specialty crops. The demand for organic produce continues to expand and is of increasing interest to PNW growers. Managing weeds and providing adequate nutrients are the two major production issues for organic producers. Economical and environmentally friendly solutions are needed for organic producers to increase production efficiency by management of weeds and nutrients. Formerly 5354-21660-001-00D (8.08). Significant Activities that Support Special Target Populations 1. Optimal strategies for incorporating bioenergy crops into irrigated Pacific Northwest Region cropping systems. Field trials were using field corn, winter wheat, switchgrass (Panicum virgatum), and polyculture mix with low, intermediate, high productivity levels by maintaining three irrigation water regimes (50, 75, and 100% of evapotranspiration (ET)). Initial measurements of above- and below-ground productivity, nutrient export, and C sequestration were made using a combination of field and laboratory studies employing standard C pool analyses and tracer (13C) analyses in this first year of the study. Measures of C-sequestration potential by laboratory incubations and 13C analyses have been set up for both the fall 2008 and spring 2009 soil samplings. 2. Determine the efficacy of co-products from agricultural-based energy production on weed and disease control and soil fertility improvement. A field trial evaluating the application of agricultural-based energy co- products (e.g. oil-seed meals, distillers grains, anaerobic digested dairy manures) to reduce the application of synthetic fertilizers was established. Potato was planted in plots containing each of three rates (112, 168 and 224 kg N/ha) of each amendment. Assessments of the soil nutrient, potato quality, and effects on soil pathogens and plant parasitic nematodes are evaluated. 3. Determine the impact of reduced tillage on soil conservation, soil physical properties, and the yield and quality response of potato and rotational crops. The Columbia Plateau Portable Wind Tunnel will be used to measure wind erosion and dust (i.e. PM10) emissions under the reduced and conventional tillage and crop this fall, 2009. 4. Evaluate the effects of deficit irrigation practices on potato yield and tuber quality. The field research has been completed and analysis of data from the field trials are in progress. 5. Soil agroecological processes (carbon and nitrogen cycling) and application rates of organic amendments to optimize physiological development of potato under irrigated organic cropping systems. This study was conducted on C and N cycling in organic production of potatoes on certified fields broken from CRP land utilizing certified chicken composts. Data analysis and evaluation are in progress. 6. Integrate sweet corn hybrids with weed suppressive traits into organic specialty crop production systems. Yield and weed suppression of four sweet corn hybrids differing in canopy development were compared against three weed management levels that consisted of various sequences of rotary hoeing and cultivation in field trials. Significant Activities that Support Special Target Populations Organic on-farm research project related to Milestone 3.A. were conducted on a organic high value vegetable farm located near Connell, WA. An on- farm Field day was conducted on June 17th, 2009, Two presentations:1) Carbon and N cycling 2) Cover Crop control using a roller crimper. Approx. 60 participants.

Impacts
(N/A)

Publications

• Nitzan, N., Boydston, R.A., Batchelor, D., Crosslin, J., Hamlin, L., Brown, C.R. 2009. Hairy Nightshade is an Alternative Host of Spongospora subterranea, the Potato Powdery Scab Pathogen. American Journal of Potato Research. 86:297-303. DOI 10.1007/s12230-009-9083-1
• Boydston, R.A., Al-Khatib, K. 2008. Exudation of mesotrione from potato roots injures neighboring plants. Weed Science. 56: 852-855.
• Boydston, R.A., Collins, H.P., Alva, A.K. 2008. Control of Volunteer Potato (Solanum tuberosum) in Sweet Corn with Mesotrione Unaffected by Atrazine or Tillage. Weed Technology. 22:654-659.
• Boydston, R. A., H. Mojtahedi, C. R. Brown, T. L. Anderson, and E. Riga. Hairy nightshade undermines resistance of potato breeding lines to Columbia root-knot nematode. Amer. J. Potato Res. 84:245-251. 2007.
• Boydston, R. A., P. J. S. Hutchinson, and R. Bellinder. Weed management. Chapter 22 in Potato Health Management. Pages 223-233. Ed. D. Johnson. APS press. 2007.
• Hamm, P. C. W. Hoy, P. J. S. Hutchinson, W. R. Stevenson, R. A. Boydston, J. 2007. M. Alvarez, A. Alyokhin, G. Boiteau, G. Dively, N. Gudmenstad, and W. Kirk. Managing Pesticide Resistance Chapter in Potato Health Management. Ed. D. Johnson. APS press. Chapter 14, Pg 123-131.
• Alva, A.K., Mattos, D., Quaggio, J.A. 2008. Advances in nitrogen fertigation of citrus. Journal of Crop Improvement. 22:121-146.
• Alva, A.K. 2009. Effects of various pre-plant and in-season nitrogen management practices for potatoes on plant and soil nitrogen status. Communications in Soil Science and Plant Analysis. Vol. 40.
• Alva, A.K., Collins, H.P., Boydston, R.A. 2009. Nitrogen Management for Irrigated Potato Production under Different Tillage. Soil Science Society of America Journal. 73:1-8.
• Paramasivam, S., Fortenberry, G.Z., Julius, A., Sajwan, K.S., Alva, A.K. 2008. Evaluation of Emission of Greenhouse Gases from Soils Amended with Sewage Sludge. Journal of Environmental Science and Health. Vol 43:178-185.
• Liu, G.D., Li, Y.C., Alva, A.K. 2009. Shannon Entropy of Ammonia Volatilization from Fertilized Agricultural Soils. In: Castalonge, O.W. editor. Agricultural Systems: Economics, Technology and Diversity. Nova Science Publishers, Inc. p. 53-65.