Nitrogen, Phosphorus and Potassium Fertilization for Winter Potatoes in Fujian

This paper established a fertilization index of N, P and K for wintertime potato based on 110 field experiments on the fertilizer efficiencies of N, P and K in main produce areas of Fujian in recent years.Results showed that applied NPK fertilizers may get significant increasing yield that were by 29.4%, 12.8% and 19.1% respectively, and theirs average efficiencies was N>K>P.There were linear relationship between yield of CK and yield of balanced fertilization.High yield critical value of soil alkali-hydrolyzable N、Olsen-P and available K were 261 mg·kg-1、55 mg·kg-1 and 123 mg·kg-1 respectively. Economic application rate on potato were N225 kg·hm-2、P2O5 88 kg·hm-2 and K2O 198 kg·hm-2 on average respectively. However,the optimum application rates in different soil fertility grades were different.Relationship between soil available NPK testing value and optimum application rate satisfied exponential model and the model realized intention that fertilization recommendation for plot according to soil testing. 28 comparative trials showed that average increasing yield was by 8.3% and net income was by 1429 Yuan·hm-2 in recommendation fertilization compared with farmers practice.The results provided scientific foundation for highly effective fertilization on wintertime potato production in Fujian.