MODELING OF FERTILIZER APPLACATION ON WHEAT, MAIZE AND RICE

Based on the results of laboratory soil testing, greenhouse studies, field experiments and demoastration plots in 1992-1993 in Yutain, Hebei province, which were designed by using the systematic approach, models for fertilizer recommendation for wheat, maize and rice were established. The yariables in the models include soil testing values, fertilization rates, adsorption coefficients and several dummy variables, such as year and location. By using these models, a EXCAL software programs were developed to give fertilizer recommendations for wheat, maize and rice for maximum ecomic return.