长期施用有机-无机肥对太湖流域土壤肥力的影响

Effects of Long Term Integrated Fertilization with Organic Manure and Chemical Fertilizers on Soil Nutrients in Taihu Lake Region

通过长期田间定位试验研究了不同处理的有机无机肥施用对稻-麦轮作体系生产力和土壤肥力的影响。5年试验结果表明:施用有机肥和施用化肥体系均能达到较高的产量水平。单施N肥和NPK配合施用在试验前2年系统生产力(水稻+小麦)没有显著差异。不同施肥处理对土壤养分有显著影响。施肥尤其是有机无机肥混施能显著增加土壤中碱解N、速效P和速效K含量。土壤中N以NO3--N形式存在,有机肥的施入显著降低了土壤中NH4+-N的含量。土壤速效K与速效P含量呈极显著相关,说明这些速效养分的同源性,可能是由有机肥施用带入土壤中的。土壤中碱解N与NO3--N含量呈显著的相关,而与NH4+-N含量没有关系,土壤速效P与有效态Fe含量呈显著相关。

A field experiment was conducted to study the effects of long integrated fertilization with organic manure and chemical fertilizers on crop yields and soil nutrients in a rice-wheat rotation system. Five year monitoring results showed both organic manure and chemical fertilizer could get a high yield level. In this region there was significant difference on the system yield in the first two years between the continuous use of N fertilizer alone and the use of NPK fertilizers together. The integrated fertilization with organic manure and chemical fertilizers increased the content of soil alkli-N, available-P and available-K. Most of nitrogen was in NO3-N form, organic manure decreased the content of NH4^＋-N. Multi-regression analysis between soil nutrients revealed that significant linear correlation between available-P and available-K due to the same origin of P and K fertilized into soil with organic manure and chemical fertilizers. Soil alkli-N was significantly correlated with NO3-N, but with insignificantly with NH4^＋-N, and soil available-P was correlated significantly with available-Fe.