Soil testing and formula fertilization index for peanut in Fujian province

Based on fertilizer response in field experiments on peanut in southeast Fujian in recent years,soil testing and formula fertilization index for peanut in Fujian province was set up.The index included 5 following: fertilization response and soil fertility grading,soil available N,P and K index,NPK optimum application rate and their proportion in different yield levels,relationship between testing value of soil available NPK and their optimum application rate,fertilization time and method.Results showed that after applying NPK fertilizers,peanut yield increased and the effect of the fertilizers was NKP.The soil fertility levels in the peanut field could be divided into three categories:high,medium and low.High yield critical value of soil alkali-hydrolyzable N,Olsen-P and available K were 136mg/kg,21mg/kg and 90mg/kg respectively.Economic fertilization on peanut were N 98 kg/hm2,P2O5 55 kg/hm2and K2O 103 kg/hm2 on average respectively,and their proportion was 1∶0.56∶1.05.But fertilization recommendation were different for different soil fertility levels.Regression equations between soil testing and optimum application rate of N,P,K were established respectively.Soil testing provided guidance for fertilization recommendation for specific soil.