磷肥对甘蓝型春油菜产量、磷肥利用效率及经济效益的影响

利用大田试验研究了不同磷肥用量对甘蓝型春油菜产量、养分积累、磷素利用效率和经济效益的影响。结果表明,在低磷土壤上施用125 kg/hm2N和135 kg/hm2K2O基础上增施磷肥,可显著增加油菜不同部位产量,其中籽粒产量平均提高12.5%,生物量平均提高29.0%。施磷明显提高油菜地上部P素含量,有利于促进油菜K素营养累积,但对N素、K素含量无显著影响。随磷肥施用量的增加,磷肥偏生产力显著下降,施磷后磷肥农学效率、磷肥表观利用率和磷肥生理利用率平均分别为4.6 kg/kg P2O5、13.0%和40.2 kg/kg P2O5,磷肥对籽粒产量的贡献率仅为10.9%。根据经济效益分析结果,青海甘蓝型春油菜生产中磷肥用量以75 kg/hm2为宜。

Effect of phosphorus fertilizers on yield and phosphorus utilization efficiency of spring hybrid oilseed rape in Qinghai

The field experiments was carried out to investigate the influence of phosphorus fertilizer on the yield,concentration of nutrients,accumulation,phosphorus utilization efficiency and benefit of spring rapeseed(Brassica napus L.)in 2009 at hybrid oilseed rape production area of Qinghai province.The result indicated that yield of different tissue at rapeseed were improved with the phosphorus fertilizer application significantly in lower available phosphorus level soil.Based on 125 kg/hm2 N和135 kg/hm2 K2O,the seed yield increased 12.5% and above-ground biomass increased 29.0% averagely compared to zero P application.With the phosphorus fertilizer application,the P concentrations at different tissue of rapeseed were promoted obviously,but the N concentration and K concentration were not changed.It was showed that the K accumulation at rapeseed was enhanced by the phosphorus fertilizer application significantly.For other words,P partial factor productivity(PFPP)was decreased with the increase of phosphorus fertilizer application rate.The P agronomic use efficiency(AEP),apparent recovery efficiency(REP)and physiological use efficiency(PEP)of rapeseed were 4.6 kg/kg P2O5,13.0% and 40.2 kg/kg P2O5,respectively.P fertilizer contribution rate for seed of rape was 10.9% in this study.According to the P fertilizer benefit analysis and considering both yield and P use efficiency,75 kg/hm2 P2O5 should be recommended to guide the spring hybrid rapeseed production in Qinghai province.