Adapting and evaluating APSIM-SoilP-Wheat model for response to phosphorus under rainfed conditions of Pakistan

Phosphorus (P) treatments were used to evaluate APSIM-SoilP-Wheat model and phosphorus use efficiency (PUE) of two wheat cultivars (NARC-2009 and Chakwal-50) during 2011-2013. Overall, the Agricultural Production Systems Simulator (APSIM) model accurately simulated dry matter, grains per spike, grain yield, biomass P, and grain P for two years, for both genotypes in response to all P fertilizer treatments. NARC-2009 had 55% higher PUE compared to Chakwal-50. Information on PUE will be helpful in breeding high PUE cultivars. Modeling results showed that the production of wheat depends on growth as well as on P uptake of the plants. The close agreement between observed and simulated results confirmed the accuracy of the model which was validated with skill scores like R-2 and RMSE. APSIM simulation proved to be valuable tool to evaluate PUE under rainfed conditions.