ARS | Publication request: CALIBRATION OF A POTATO GROWTH MODEL FOR PREDICTION OF NITROGEN DYNAMICS IN POTATO SYSTEMS IN THE PACIFIC NORTHWEST

Submitted to: American Society of Agronomy Meetings
Publication Type: Abstract Only
Publication Acceptance Date: October 1, 2005
Publication Date: November 7, 2005
Citation: Marcos, J., Stockle, C., Alva, A.K., Timlin, D.J., Reddy, V. 2005. Calibration of a potato growth model for prediction of nitrogen dynamics in potato systems in the pacific northwest. American Society of Agronomy Meetings. (On CD)

Technical Abstract: Tools to improve nitrogen (N) management for potatoes in the Pacific Northwest (PNW) are desirable in view of the concern on non-point source pollution of nitrate into groundwater in the Columbia Basin production region which is characterized by sandy soils and possible N inputs in excess of crop N requirement. A potato growth model was developed and integrated into the multi-year, multi-crop simulation mode CropSystVB to improve overall model capabilities for the assessment of N fate under different nitrogen and irrigation regimes in potato systems. In the integrated model,CropSystVB simulates the soil-water-plant-atmostphere system for a crop rotation, as well as the soil water and nitrogen budgets. When the crop rotation is potato, the potato model simulates potato growth and development and plant carbon and N balances. A field experiment was conducted to botain crop data requird to parameterize the potato crop model under different levels of N and irrigation. Model simulations were compared to seasonally measured date of dry matter, leaf area index, plant N and yield of potatoes grown with 3 levels of applied N (168, 336, and 504 kg/ha) and 2 levels of applied water (100 and 75% ET). Results showed that the model simulated plant N and dry matter partition and yields adequately. Improved accuracy in the simulation of potato N and carbon balances by the integrated model demonstrates that this model can be used to predict soil and plant N dynamics and production of potato-based cropping systems.