长期秸秆与氮磷肥配施对土壤钾素形态的影响

以山东省黄河冲积平原低肥力潮土为供试土壤,经18a盆栽土培定位试验后,采用化学形态分析方法对土壤的钾素形态进行了研究。结果表明,长期秸秆还田并配施适量的化肥,能明显提高潮土缓效钾和速效钾的释放效应,对矿物钾的有效化也有一定效果。在秸秆还田量分别为2250、4500、6750kg/hm2范围内,土壤水溶性钾、非特殊吸附钾、特殊吸附钾、非交换钾与秸秆还田量呈显著正相关;与矿物钾呈显著负相关。长期秸秆还田土壤钾素年度变化规律:非交换钾、特殊吸附钾呈逐年上升趋势;水溶性钾、非特殊吸附钾、矿物钾呈逐年下降趋势。

Effect of Long-term Straw Combination to Fertility on Potassium Forms

Study was carried out on fluvo-aquic soil of low fertility coming from Huanghe River plain for 18 years. The research of potassium forms applied a chemical analytic method. The results show that the straw returning combination to fertility improves release of slow-release K and available K, and availability of mineral K. As straw application rate at the range of 2250?4500?6750kg hm-2,soil non-exchangeable K, water soluble K, specifically absorbed K and non-specifically absorbed K are all positively related to the amount of straw remarkably, while mineral K is negatively correlative. The variant regularity of soil K is that non-exchangeable K and specifically absorbed K are increasing, but the other forms of K are decreasing.