土地利用和轮作方式对旱地红壤生化性质的影响

Effects of Land Management and Crop Rotation on Upland Red Soil Biochemical Properties

研究不同土地利用和轮作方式对旱地红壤肥力的影响对提高红壤质量具有十分重要的指导意义。本研究以湖南省桃源县的林地、大豆-油菜轮作、玉米-休闲轮作土壤为研究对象,明确了林地、农地土壤及农地不同轮作方式对土壤化学和生物性质的影响。结果表明,林地土壤的pH、有机碳、速效养分、微生物生物量碳及酶活性(纤维素酶、酸性磷酸酶、转化酶、蛋白酶)均显著高于农地土壤;大豆-油菜轮作土壤的pH、养分含量、微生物生物量碳含量及其微生物熵在大多数情况下高于玉米-休闲轮作,但轮作处理对各酶活性的影响并不完全一致。这种不一致性可能与不同酶对由不同利用和轮作方式导致的土壤性质差异的敏感性不同所致。土壤有机碳和pH与各生物指标均呈显著正相关关系,表明提高该地区的土壤有机碳含量对于维持土壤的生化性质具有重要的作用。

Land management and crop rotation apparently affect upland red soil productivity. This study aimed at the effects of forest land, arable soil and different crop rotation systems on soil biochemistry properties. The results of the experiment in forest land, soybean-rape rotation and maize-fallow rotation in Taoyuan County, Hunan Province showed that： in the forest lands, soil pH, organic carbon, available nutrients, microbial biomass carbon and enzyme activity （cellulase, acid phosphatase, invertase, protease） were higher than those of the arable soils. Soil pH, nutrients contents, microbial biomass carbon and microbial quotient in soybean-rape rotation were higher than those in maize-fallow rotation, but the response of enzyme activities in different crop rotation treatments was not uniform, which may be due to the differences in the soil enzyme sensitivity induced by different land management practices and crop rotation systems. There were significant relationships between different microbial indicators and soil organic carbon or pH, which indicated that the organic carbon and pH were indicators of soil quality in upland red soils. The study manifests that increasing soil organic carbon in this area is important to maintain and improve the upland red soil biochemistry properties.