A Study Yield Model of Rice Growing on Long-cultivated Land in Zhangye City,Gansu Province

Effects of nitrogenous and phosphate fertilizers on the yield of rice growing on various long-cultivated land and the relation between the two nutrients were studied by revolving regression designed field experiment.Based on the experimental data a regressive yield model was established.Then by analysis of the model suitable rate of ap;lication of the two fertilizers on present condition can be determined.It was also concluded that for increasing rice yield phosphate fertilizer was more important than nitrogenous fertilizer.