Nutrient uptake requirements with increasing grain yield for rice in China

10 t ha-1,respectively.Phosphorus（P）and potassium（K）requirements showed increasing trends,from 3.51 and 19.87 kg per t grain for10.0t ha-1range.In conclusion,nutrient requirement varied with increasement of grain yield,and N,P and K presented various response trends,increasing,declining or stagnating,which would be of great benefit for improving fertilizer strategies.