Tuesday, November 14, 2006

Using a Decision Support System for Simulating Yield of On-Farm Crops Rotations.

Axel Garcia y Garcia1, Larry C. Guerra1, and Gerrit Hoogenboom2. (1) The Univ of Georgia, 1109 Experiment St, BAE Bldg, Griffin, GA 30223, (2) Univ. Of Georgia, Dept Biology & Agriculture Engineering, 1109 Experiment St., Griffin, GA 30223-1797

Crops rotations are an important component for farming systems with impact on weed's control, pests' development, yield potential, and economic return. Decision support systems integrate the complexity of a farming system and can help studying the impact of long-term rotation sequences as well as the impact of climate variability and rotations on yield. The objective of this study was to evaluate the capability of the Decision Support System for Agrotechnology Transfer (DSSAT) for simulating yield of cotton, maize, and peanut under various crop rotation sequences for selected farms in southwest Georgia. Field data were obtained from six fields of three selected farmers. Growth analysis data were obtained from an on-farm crops growth and development monitoring period of three years conducted at two week interval from 2003 to 2005; weather data collected by the weather stations of the Georgia AEMN were used, and soil profile information was obtained from the USDA-NRCS. The sequence analysis program and the CSM model of DSSAT v4 were used for simulating three rotation sequences that  were observed in the farmers’ fields, including Cotton-Cotton-Peanut, Cotton-Peanut-Cotton, and Maize-Maize-Peanut as the main crop components and winter forage or winter fallow as complements. Crops' yield from the various rotation sequences, including winter forage or winter fallow, were satisfactory simulated. The results demonstrated the ability of the DSSAT as an effective tool for cropping systems research. Further studies will focus on the impact of the climate variability on long-term rotations of the major crops in the southeastern USA using the DSSAT system.

Handout (.pdf format, 139.0 kb)