Evaluation of Model Simulation of Nitrogen
Mineralization in a Potato Rotation System. (4923)
Authors:
A. Alva* - USDA-ARS Prosser WA J. Marcos - WSU Prosser WA C. Stockle - WSU Pullman WA
V. Reddy - USDA-ARS Beltsville MD D. Timlin - USDA-ARS Beltsville MD
Abstract:
In the irrigated agricultural production region of the Pacific Northwest, potato is rotated with wheat, corn, and to a limited extent with alfalfa. Total nitrogen (N) returned to the soil by incorporation of the respective crop residues account for 40 to 147 kg ha-1. Cover crops used in this production systems, i.e. mustard, Sudan grass, and wheat provide 40 to 128 kg N ha-1. Mineralization of N from these crop residues render N into plant available forms. Three years field investigations
showed that the mineralization of N from the above crop residues contribute 44 to 88 mg kg-1 on an annual basis. The rate of mineralization is dependent on the soil and climatic conditions. The potato growth simulation model, SIMPOTATO (Hodges et al., 1992), was integrated with the multi-year and multi-crop model CROPSYST (Stockle et al., 1994) to simulate crop growth and N dynamics in potato rotation systems. The model simulation of the N mineralization from different crop residues was compared with the field measured data. Improved accuracy of the model simulation of N dynamics in the potato rotation system provides an important tool in the decision making process to determine the amount of N to be applied to meet the respective crop N requirement. This will in turn minimize the N losses from the rotation cropping systems.
Speaker Information: Ashok Alva, USDA-ARS Prosser WA, 24106 N Bunn Rd., Prosser, WA 99350; Phone: 509-786-9205; E-mail: [email protected]
Session Information: Monday, November 1, 2004, 4:00 PM-6:00 PM Presentation Start: 4:00 PM (Poster Board Number: 0120)
Keywords: simulation; nitrogen; mineralization; potato system
