广西沿海高磷低钾沙壤土种植甘薯氮磷钾施肥效果分析

N,P and K Fertilizer Use Efficiency of Sweet Potato Planted in Coastal High P and Low K Sandy Loam Soil

在沿海淡酸田速效磷含量高、速效钾含量低的沙壤土上进行甘薯品种红姑娘缺素和氮磷钾肥配合施用试验。结果表明,不施肥处理鲜薯产量为15457.5kg/hm2;氮磷钾肥配合施肥处理鲜薯产量最高,为26893.5kg/hm2,与不施肥处理和不施钾处理相比较,增产达极显著水平,与不施氮处理比较,增产达显著水平,与不施磷处理比增产不显著;不施钾处理产量最低,仅为12798kg/hm2。提出防城港市沿海淡酸田沙壤土稻—薯轮作种植红姑娘甘薯品种的推荐施肥配方为氮75kg/hm2、五氧化二磷45kg/hm2、氧化钾270kg/hm2,磷不宜多施,土壤的速效磷接近100mg/kg时不必施磷肥,氮肥和磷肥宜在前期施,钾肥宜在甘薯中期大培土时施。

Experiments with five treatments of N,P and K combined application on sweet potato planted in coastal high P and low K sandy loam soil were carried out.The results showed that the yield of sweet potato without fertilizer was 15457.5kg/hm^2 and the treatment of N,P and K combined application had the highest yield of 26893.5kg/hm^2,with the significant difference from those fertilizer zero,K zero treatment and N zero treatment,but no significant difference from P zero treatment.The treatment of K zero had the lowest yield of 12798kg/hm^2.According the results,the optimum fertilizer amount of N,P2O5 and K2O to be recommended was 75kg/hm^2,45kg/hm^2,and 270kg/hm^2,respectively.It was not necessary to apply P fertilizer when the rapidly available P in the soil was higher than 100mg/kg.It was proper to fertilize N and P at the earlier growing stages,but fertilize K at the middle stage.