Effect of nitrogen,phosphorus and potassium fertilizers on yield and chemical fertilizers utilization of spring hybrid oilseed rape in Qinghai

Field experiment was carried out to investigate the influence of nitrogen(N),phosphorus(P) and potassium(K) fertilizers on yield,nutrients accumulation rate and utilization efficiency of spring hybrid oilseed rape(Brassica napus L.cv Qingza 2) in Huzhu county,Qinghai province.Results showed that seed yield of Qingyouza 2 was significantly improved by N and P fertilizers,but not by K fertilizer.Compared to no fertilizer control,N,P and K accumulation in rape shoot were enhanced significantly after using corresponding fertilizers(P0.05).From the study,it can be concluded that the agronomic efficiency of different fertilizer were 5.3kg/kg N,5.6kg/kg P2O5 and 1.7kg/kg K2O respectively,and the noticeable recovery efficiency of different fertilizer were N 33.6%,P2O5 7.8% and K2O 52.0% respectively.The partial factor production of nitrogen,phosphorus and potassium fertilizers in spring oilseed rape were 28.0.kg/kg N,46.7kg/kg P2O5 and 26.0kg/kg K2O respectively.In this study,while the seed yield of 3 504kg/hm2 with the nitrogen,phosphorus and potassium applied altogether,4.6kg N,2.0kg P2O5 and 5.6kg K2O have been absorbed from soil as 100 kilograms spring oilseed rape produced,and the ratio of N,P2O5 and K2O was 1∶ 0.43∶ 1.21.In spring oilseed rape productive practice of Qinghai province,improvement of soil fertility and balancing fertilization could play important rloes in achieving high yield.