保护性耕作对旱作玉米土壤微生物和酶活性的影响

研究了玉米关键生育时期不同保护性耕作措施对旱作玉米田土壤微生物和酶活性的影响。结果表明：随着玉米生育时期的推进，免耕留低茬、免耕留低茬＋秸秆覆盖、免耕留高茬＋秸秆覆盖、免耕留高茬4个处理土壤微生物细菌、放线菌、真菌和纤维素分解菌数量均显著增加，土壤过氧化氢酶、脲酶和蔗糖酶的活性增强。在全生育期，保护性耕作处理土壤微生物细菌、放线菌、真菌和纤维素分解菌数量比传统耕作分别提高41.9%、470.1%、67.9%和65.7%，土壤过氧化氢酶、脲酶和蔗糖酶的活性分别提高15.0%、18.5%和57.3%，且此效应受玉米生长发育进程的影响。表明保护性耕作有利于增加土壤有机质的累积，提高土壤肥力。

Effects of Different Conservation Tillage on Soil Microbes Quantities and Enzyme Activities in Dry Cultivation

The effects of the different conservation tillage methods on quantities of soil microbes and enzyme activities had been tested in critical growth duration of maize in dry sloping sites. The result indicated that non-tillage and short stubble, non-tillage and low stubble with residue cover, non-tillage and high stubble with residue cover, and non-tillage and high stubble which all improved significantly quantities of bacteria, actinomycete, fungi, and cellulose-decomposing bacteria in soil, and improved the activities of the catalase, urease, and sucrase. Compared with the traditional cultural, the soil with protective tillage in all grown duration of maize, in which quantities of bacteria, actinomycete, fung, and cellulose-decomposing bacteria increased 41.9%, 470.1%, 67.9% and 65.7% respectively; while activities of the catalase, urease and sucrase increased 15.0%, 18.5% and 57.3% respectively. Moreover the effects had been influenced by growth and development of the maize. Above all, which detected that conservation tillage increased the soil organic matter and improved the soil fertility.