保护性耕作对农田土壤不同养分形态的影响

Effects of Conservation Tillage on Different Soil Nutrient Forms

本试验采用田间取样和室内分析相结合的方法，研究了保护性耕作模式对土壤中有机质、碱解氮、速效磷、速效钾动态分布的影响。在0-10cm土层，保护性耕作条件下秸秆还田各处理的土壤有机质含量较无秸秆还田处理都有大幅度提高，但在10—20cm土层，深松秸秆还田处理和常规秸秆还田处理的有机质含量明显高于保护性耕作处理；0—20cm土层的碱解氮含量无秸秆还田处理总体上高于秸秆还田处理，而在20—40cm土层的碱解氮含量无秸秆还田处理总体上低于秸秆还田处理碱解氮含量，以耙耕处理提高的幅度最大，深松处理提高的幅度最小；0—20cm土层秸秆还田处理速效磷含量显著高于无秸秆还田处理速效磷含量，0—20cm土层的速效磷含量显著高于20—40cm土层，在20—40cm土层，保护性耕作处理秸秆还田与非秸秆还田处理之间差异很小；0—20cm土层土壤速效钾含量显著高于20—40cm土层，在0—20cm土层秸秆还田处理高于对应的无秸秆还田处理，在0—20cm土层中，常规耕作处理无论是秸秆还田处理还是无秸秆还田处理整体上都比保护性耕作处小，这可能与常规翻耕后秸秆的深埋有关，但在20—40cm土层中，常规耕作处理在整体上却显著高于其他保护性耕作处理。保护性耕作处理土壤有机质、全氮、速效钾、速效磷含量有表层富集、下层贫化的现象；秸秆还田能显著提高保护性耕作0-10cm土层土壤有机质、全氮、速效钾和速效磷含量。0—20cm土层土壤碱解氮含量非秸秆还田处理大于秸秆还田处理，但在20～40cm土层，土壤碱解氮含量秸秆还田处理大于非秸秆还田处理，说明土壤的氮素供应情况秸秆还田处理优于秸秆不还田处理。

The objective of study is to investigate the effects of conservation tillage on soil nutrient content and distribution condition in soil. A field experiment used the methods of the indoor field sampling and analysis to study the effects of conservation tillage on soil organic matter, alkali-hydrolysable nitrogen content, available phosphorus content,available potassium content on soil nutrient content and distribution condition in soil. In the 0 - 10cm soil layer, organic matter content of straw present condition treatment than straw absent treatment have greatly improved under the conservation tillage, but in the 10 - 20cm soil layer, straw present ＆ subsoil tillage and straw present ＆ conventional tillage was significantly higher than conservation tillage treatment;0 - 20cm soil layer alkali-hydrolysable nitrogen content, straw absent handle on the whole higher than the straw present, and alkali-hydrolysable nitrogen content, the straw present on the whole less than straw in the 20 - 40cm of soil layer absent also dealt with straw mulch to deal with alkali-hydrolysable nitrogen content, to straw absent ＆ harrow tillage of handling the largest increase, straw present ＆ subsoil tillage increased the rate of minimum ;0 - 20cm soil layer available Phosphorus content,of straw returning treatment was significantly higher than that straw absent available phosphorus content,0 -20cm soil layer phosphorus content was significantly higher than 20 -40cm soil layer,20 -40cm layer in the soil, conservation tillage treatment straw present and straw absent dealing with non-small difference between ;0 -20cm layer of available potassium content was significantly higher than the 20 - 40cm layer, in the 0 - 20cm soil straw present treatment than the straw absent, dealing with both conventional tillage straw present treatment or no treatment straw on the whole than the small conservation tillage, which may be related to conventional tillage after straw deep, but in 20 - 40cm soil layer of conventional farming handle on the whole is significantly higher than that of other conservation tillage. Conservation tillage oil organic matter, alkali-hydrolysable nitrogen content, available phosphorus content, available potassium content, lower deck of depleted;straw can significantly improve the conservation tillage 0 -10cm soil layer of soil organic matter, alkali-hydrolysable nitrogen content, available phosphorus content, available potassium content. 0 - 20cm layer of soil nitrogen content of alkali-hydrolysable nitrogen content, more than straw absent treatment, but in 20 -40cm layer of alkali-hydrolysable nitrogen content processing more than straw absent treatment, that the soil Nitrogen supply situation is better than dealing with straw present also does not deal with straw absent.