ASSESSMENT OF POTENTIAL YIELD AND CLIMATE CHANGE SENSITIVITY OF SELECTED DRYLAND CROPS IN CAGAYAN VALLEY, PHILIPPINES USING SIMULATION MODE LS

Abstract

Corn and peanut are major upland crops in Cagayan Valley. Emerging food and biofuel crops like sweet sorghum requires less water were recently introduced to increase the productivity in the rainfed ecosystem. However , little information is available on the potential productivity of these upland crops and analysis on the production constraints including climate change sensitivity. This study aimed to determine potential yield, yield gap, production constraints and clim ate change sensitivity of peanut, sweet sorghum and corn crops in Cagayan Valley through the use of Decision Support System for Agrotechnology Transfer (DSSAT) simulation modeling. Simulation results using DSSAT model showed highest potential yield of pean ut, corn and sweet sorghum is 2267 kg/ha when planted in October 15, 7,734 kg/ha when planted in June 15, and 6,570 kg/ha when planted in February 1 respectively, under rainfed condition. Under non stressed conditions, the highest obtainable yield is 4805 kg/ha when planted in December 15; peanut is 7,953 kg/ha planted in May 1 for corn and 7,380 kg/ha planted in February 1 forsweet sorghum. Large yield gaps exist between actual farmers yield and potential yield. Overall, the average yield gap is 1000 kg/ha for peanut; 2,460 kg/ha for maize; and 1700 kg/ha for sweet sorghum, indicating the potential for future yield improvements. Low rates of nitrogen application, pests and diseases were the main factors causing yield gaps of these crops. Climate variability is another factor as DSSAT was able to capture the effect of drought periods, which resulted to underestimated yield result. The study demonstrated the potential of using dynamic crop simulation model in assisting with strategic decision making for crop p roduction and land use planning. It indicated the possibility of using DSSAT model as an information technology tool to increase yield of dryland crops for the agricultural production areas.