Submitted to: International Soil and Water Conservation Conference
Publication Type: Abstract Only
Publication Acceptance Date: August 1, 2003
Publication Date: July 1, 2004
Citation: ALVA, A.K., COLLINS, H.P., BOYDSTON, R.A., MARCOS, J., REDDY, V. MANAGEMENT STRATEGIES TO IMPROVE SUSTAINABILITY OF IRRIGATED POTATO ROTATION CROPPING SYSTEMS. INTERNATIONAL SOIL AND WATER CONSERVATION CONFERENCE (In Press) 2004. Technical Abstract: The Pacific Northwest (PNW) of United States (Washington, Idaho, and Oregon) produces up to 55% of the Nations total Potato production, 20 M metric tones. This region is dry; therefore, irrigation is the key for profitable production. Soils are sandy, thus subject to wind erosion as well as vulnerable to leaching of chemicals and nutrients. This report summarizes the results of a number of projects in progress to minimize the negative effects of potato production practices on the environment. Cover crops provide numerous benefits in various cropping systems. The effects of four fall-planted cover crop treatments (white mustard, Sudan grass, winter wheat, and oat-hairy vetch) and soil fumigation on soil micro flora, weed and disease incidence, and soil nutrient cycling are being evaluated in a crop rotation of winter wheat 2 yrs of sweet corn - potato. Temporal gradients of microbial C and N; microbial community structure, diversity, function, and activity are being determined. Weed seed survival, seed bank, populations, and biomass are also measured. Mineralization of nitrogen (N) from crop residues and soil organic matter during crop growing season provides a source of readily available N, while could contribute to N leaching losses during the off season. On an annual basis the N transformation from crop residues and soil organic matter, into available forms (ammonium plus nitrate), after harvesting alfalfa, field corn, sweet corn, potato and wheat varied from 60 to 90 mg/kg N, in the top 30 cm soil. Mineralization of N varied for crop residues, but peaked during May to August. Crop simulation models can be used as a tool for improved water and nitrogen management for crop production. About 750 mm of water is applied to Potatoes in the PNW. Potato is sensitive to water and nitrogen stresses. Best management of these inputs is important to satisfy the crop needs for profitable production of quality tubers, while minimizing leaching below the root zone. SIMPOTATO, a crop simulation model for potato incorporates simulation of water and nitrogen balances. This model can be used to create different scenarios of water and nitrogen applications to determine the best alternatives for management of potato for optimum yields of high quality tubers with minimum negative impacts on the environment.