中文摘要：

土壤微生物是土壤的重要组成部分,对土壤肥力的形成和植物营养的转化起着积极的作用,是土壤肥力和环境变化的重要指标。通过土壤微生物量测定,研究新银合欢植物篱对紫色土区坡地农耕地、经济林地2种土地利用方式及10°,15°坡度下0-20cm土层土壤微生物特性的影响。研究发现：新银合欢植物篱可以明显提高土壤中细菌、放线菌、真菌的数量及微生物量碳、氮含量;植物篱对经济林地小区土壤微生物数量,微生物量碳、氮的影响作用总体上大于对农耕地小区的,同时对10°农耕地的影响作用总体上大于对15°农耕地的;下坡的三大微生物数量,土壤微生物量碳,氮平均含量明显比上坡的多,下坡距离植物篱带最近采样点处三大微生物数量,土壤微生物量碳,氮含量明显比其他采样点的多。表明定植新银合欢植物篱有利于减少土壤肥力衰退,有利于土壤碳、氮素固持。

英文摘要：

As a significant constituent part,soil microbe,an important index of soil fertility and environment change,has a positive effect on formation of soil fertility and transformation of plant nutrition.On the basis of determination of soil microbial biomass,effect of Leucaena leucocephala hedgerows on 0-20 cm soil microbial characteristics under cropland and economic forest land,10° and 15° in the purple soil area were investigated.Research showed that： Leucaena leucocephala hedgerows obviously increased quantities of bacteria,actinomycetes and fungi,soil microbial biomass carbon and soil microbial biomass nitrogen content.On the whole,the effects of hedgerows on quantities of bacteria,actinomycetes and fungi,soil microbial biomass carbon and soil microbial biomass nitrogen contents under economic forest land were more great than those of cropland,meanwhile,the effects of hedgerows on soil microbe quantities,microbial biomass carbon and microbial biomass nitrogen content in 10° cropland were more great than those of 15° cropland.Moreover,quantities of bacteria,actinomycetes and fungi,soil microbial carbon average contents and soil microbial nitrogen average contents on downhill were significantly more than those of uphill,and quantities of bacteria,actinomycetes and fungi,soil microbial carbon,nitrogen contents of the nearest sampling point to the hedgerows on downhill were much more than others.The results indicated that Leucaena leucocephala hedgerows planting was beneficial to reducing soil fertility decline,immobilization of soil carbon,nitrogen immobilization.