通过对棉田进行不同量的稻草覆盖,研究了不同稻草覆盖量对土壤的化学性状和生物学性状的影响.结果表明:稻草覆盖不但能改善土壤的化学性状,增加土壤微生物,同时能增强土壤酶活性.棉花种植前和收获后相比,稻草覆盖能够明显增加土壤有机质、全氮、全磷、全钾和速效钾的质量分数,并随着覆盖量的增加而升高,而速效氮、速效磷质量分数在棉花种植前和收获后相比呈下降趋势.少量覆盖最有利于土壤微生物的增加,中量覆盖放线菌和硝化细菌会有所减少,大量覆盖反而会让部分微生物减少.另外,稻草覆盖处理均有提高土壤中过氧化氢酶、蔗糖酶及脲酶活性的作用,且过氧化氢酶、蔗糖酶的活性随着稻草覆盖量的增加而增强.%The impacts of diverse amounts of rice straw mulch upon the chemical and biological characteristics of an upland red soil under cotton have been investigated. The straw mulch treatments improved the chemical characteristics of the soil, but also increase the soil microbial biomass and stimulated soil enzyme activities. Comparison of the soils pre-planting and post-harvest, showed that increasing the amount of straw mulch significantly increased the soil organic matter, total nitrogen, total phosphorus, total calcium and available calcium concentrations in the soil. However, the concentrations of available nitrogen and available phosphorus declined in the cotton field post-harvest. The smallest mulch application rate was best for the increasing soil microbial activity. The treatment with the middle application rate reduced the amounts of actinomycetes and nitrifying bacteria. Treatment with a high application rate could reduce important components of the microbial activity. In addition, the activities of catalase, invertase and urease in soil were improved by the straw mulching treatments, and the activities of catalase and invertase increased with the rate of mulch application.
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