赫山区柑橘施肥指标体系研究

Study on Fertilization Index System of Citrus in Heshan District

通过对赫山区6个试点的"3415"试验,建立了赫山区柑橘施肥效应的6个函数模型。根据函数模型,将赫山区种植柑橘的土壤划分为高、中、低3种地力水平,其目标产量为2 750、2 340、1 470 kg/667m2,推荐施氮量分别为12.3、11.2、10.4 kg/667m2;各地力水平的土壤P、K含量指标为,高:P≥14 mg/kg、K≥70 mg/kg,中:P 10～14 mg/kg、K 60～70 mg/kg,低:P<10 mg/kg、K<60 mg/kg;高、中、低3种地力水平P2O5和K2O的推荐施用量分别为5.5和7.1 kg/667m2、6.1和8.4 kg/667m2、6.4和8.6 kg/667m2。得出高、中、低3种地力水平施用N、P2O5、K2O的最佳配比分别为1∶0.45∶0.58、1∶0.54∶0.75、1∶0.62∶0.83。

Through conducting ＂3415＂ experiment in six places of Heshan District,six function models of fertilization effect for citrus in Heshan District were established.According to the function models,the citrus-planting soils in Heshan District were divided into three levels of soil fertility（high,medium and low）,the goal of yield in soils with high,medium and low soil fertility were 41 250,35 100 and 22 050 kg/hm2,and the recommend N fertilizer rate was 184.5,168 and 156 kg/hm2;the content indexes of P and K in soils with high,medium and low soil fertility were P≥14 mg/kg and K≥70 mg/kg,P=10～14 mg/kg and K=60～70 mg/kg and P10 mg/kg and K60 mg/kg,respectively;the recommend fertilizer rates of P2O5 and K2O in soils with high,medium and low soil fertility were 82.5 and 106.5 kg/hm2,91.5 and 126 kg/hm2 and 96 and 129 kg/hm2.Therefore,it concluded that the optimum applying ratios of N,P2O5 and K2O in soils with high,medium and low soil fertility were 1∶0.45∶0.58,1∶0.54∶0.75 and 1∶0.62∶0.83,respectively.