北方旱作农田保护性耕作对土壤线虫物种组成和营养类群的影响

Impacts of the conservation tillage on soil nematode genera composition and trophic groups in upland farming systems, north China

以辽宁彰武县保护性耕作示范推广基地土壤为研究对象,对比研究了传统犁耕和保护性耕作(6年免耕秸秆覆盖)条件下土壤线虫的总数、物种组成和营养类群的差异及其与土壤理化指标的关系,结果表明:各处理共观测到土壤线虫34个属,其中拟丽突属(Acrobeloides)、板唇属(Chiloplacus)、螺旋属(Helicotylenchus)、矮小属(Merlinius)和短体属(Pratylenchus)为优势属。较犁耕相比,保护性耕作显著提高了土壤线虫总数和各营养类群线虫多度、改变了线虫优势属和营养类群的结构。相关分析表明,保护性耕作条件下土壤线虫的总数、各优势属和营养类群与土壤养分含量、pH和孔隙度等理化性质之间关系密切。研究证明土壤线虫群落的物种和营养结构对保护性耕作土壤质量变化具有良好的生物指示作用。

Soil nematode genera composition and trophic groups were compared between traditional plow and conservation tillage （6-yr combination of no-tillage Liaoning Province, in order to provide scientific basis for tillage （PT） and straw mulch） in a case study in Zhangwu county of assessing soil ecological effects of the conservation tillage. During the study period, 34 genera were identified, in which Acrobeloides, Chiloplacus, Helicotylenchus, Merlinius and Pratylenchus were dominant genera. The results showed that the conservation tillage significantly increased total soil nematode number and all trophie group abundances, and altered structure of dominant nematode genera and trophic groups compared to the plow tillage. Correlation analysis indicated that total number, dominant genera and trophic structure of soil nematode were closely related to soil physico-chemical properties such as nutrient contents, pH and porosity. Our res assessing the conservation uhs suggested that soil nematode community structure can be effective bio-indicators for tillage effects on soil quality.