Application of Crop Modeling and Aegis/Win for Optimizing Agricultural Inputs in Soils.
B. L. Harikrishna, G. S. Dasog, P. L. Patil, and K. M. Anegundi. Dept of Soil Science and Agricultural Chemistry, Univ of Agricultural Sciences, Dharwad, 580005, India
Crop simulation models predict the effects of weather and various soil properties, and agronomic practices on nutrient dynamics and crop growth processes leading to improvements in the efficiency of fertilizer management. Crop simulation models coupled with a AEGIS/WIN, maps model outputs is of interest to decision makers. This paper outlines the need for crop model geographic information systems, the possible uses of such systems. It describes, a study investigating extrapolation of simulated results to a nine different soil series of Jokanatti distributary GLBC command, Karnataka, India) using a CERES maize simulation model coupled with a AEGIS/WIN. The spatial databases of the AEGIS/WIN contain information on soils, weather and other inputs needed by the maize model and the system allows regional analyses of model output to be performed and maps to be drawn. In CERES, predicted number of days to anthesis, physiological maturity, grain weight and grain yield of maize closer (% RMSE <10) to observed values for both the seasons, which indicated that the model predictions were genuine and acceptable. Whereas, leaf area index (LAI) and nitrogen uptake appeared to be overly sensitive to varying soil depth, N-doses and its splits but with reference to dry matter yield, model response was satisfactory. Interestingly, higher production of maize was noticed under post monsoon than monsoon season. The AEGIS/WIN simulated comparatively more number of days to mature, higher straw and grain yield and N-uptake by maize in respect of deep soils, due to its favourable physico-chemical properties. On the other hand, the simulated results for shallow soils recorded comparatively lower with respect to all above said parameters due to its poor physico-chemical properties, especially shallow depth. The other soils of intermediate depth recorded intermediate values.