|Fraisse, Clyde - WASHINGTON STATE UNIV|
|Marcos, Javier - WASHINGTON STATE UNIV|
Submitted to: ASAE Annual International Meeting
Publication Type: Proceedings
Publication Acceptance Date: July 27, 2003
Publication Date: October 1, 2003
Citation: Fraisse, C., Marcos, J., Alva, A.K., Collins, H.P. 2003. Evaluation of simpotato and substor for potato growth and development simulation in the Columbia Basin. ASAE Annual International Meeting. Transactions of the American Society of Agricultural Engineers. (On CD). Interpretive Summary: Crop growth simulation models are useful tools to understand the pattern of crop growth which is important to manage the application of water and nutrients in order to match the quantities applied with those required by the crop plants. Excess application of water and nutrients during the slow growing period can result in nutrient losses which can contribute to groundwater contamination. In this study two potato growth models, i.e. SIMPOTATO and SUBSTOR, were compared for simulation of potato growth using the input information as relevant to the predominantly irrigation dependent growing region in the Columbia Basin area of the Pacific Northwest. The weather conditions in this region are favorable for high productin of high quality processing potatoes. The results revealed both models were quite comparable for simulation of potato growth. Further studies are in progress to link the SIMPOTATO model with CROPSYS model to enhance the utility of this model to simulate crop growth in a potato-wheat-corn rotation system and to predict the fate of nitrogen with specific attention to leaching losses.
Technical Abstract: Potatoes are sensitive to many stresses that influence tuber growth and development. Stresses caused by pests, improper nutrition or water management can greatly impact yield and the quality aspects of the crop. Water and nitrogen are the two biggest (although not necessarily most costly) inputs for potato production. Farmers in SE Washington cannot be expected to reduce these inputs just to save money because of their low value relative to the expected value of the crop especially if reducing inputs reduces the value of the crop. Coarse, sandy soils with low organic matter (0.5% or less on uncropped land) have low capacity to hold water (5% available by volume). Where excess water and nitrogen are applied, there is a strong possibility of water and solute movement below the root zone and eventually into the ground water supply. However, if water and nitrogen are applied at the same rate as the plant extracts them from the soil, little or nothing will be moved down through the soil during the crop models (SIMPOTATO and SUBSTOR) as an aid for improved water and nitrogen management of potato cropping systems. The performance of the models for simulation of plant growth during the 2002 cropping season was evaluated. Both models are weather driven and based on the CERES-maize model which requires daily rainfall, solar radiation, and maximum and minimum air temperature, in addition to crop management data for simulation of crop growth and development.