江苏省不同农业区土壤线虫群落分布特征

调查了江苏省不同农业区农田土壤线虫群落多样性，分析了土壤线虫数量和群落结构与土壤环境因子的关系，并探讨了土壤线虫对土壤健康的生物指示作用.结果表明： 农田土壤线虫共鉴定出2纲7目19科41属.6个农业区的土壤线虫的密度、群落组成均具有一定的差异性.沿海农业区的线虫数量最多(每100 g干土400条)，显著高于徐淮、宁镇扬和沿江农业区(P＜0.05)，而沿江农业区的土壤线虫数量最少(每100 g干土232条)，这可能是由于土壤质地、年均降雨量和年均气温等因素的差异造成的.地理位置相近的农业区线虫优势属相似.相关性分析结果显示，土壤线虫数量与土壤有机质、全氮、速效氮、速效钾和速效磷均呈显著正相关关系；RDA分析表明，土壤全氮含量、速效磷及pH对线虫群落种属组成影响较大.分析江苏省农田土壤线虫群落空间分布特征，可为农田土壤生态系统健康状况评价提供数据支撑.

Characteristics of soil nematode community of different agricultural areas in Jiangsu Province,China.

This paper investigated the genus diversity of soil nematodes of different agricultural areas in Jiangsu Province, analyzed the relationship between soil nematodes and soil environmental factors, and discussed the roles of soil nematodes as biological indicators of soil health. The results showed that, a total of 41 nematode genera were found in all six agricultural areas, belonging to 19 families, 7 orders, 2 classes. The numbers and community compositions of nematodes were obviously influenced by soil texture, fertilization and tillage practices. In all six agricultural areas, the numbers of nematodes in coastal agricultural area (400 individuals per 100 g dry soil) were significantly larger than that in Xuhuai, Ningzhenyang, and riverside agricultural areas. While the smallest number of nematodes was found in Yanjiang agricultural area (232 individuals per 100 g dry soil), which might be due to the differences in soil texture, annual rainfall and annual air temperature and other factors. The dominant genera of nematodes were similar in the adjacent agricultural areas. Correlation analysis showed that there was a significant positive correlation between the number of soil nematodes and levels of soil nutrients (soil organic matter, total nitrogen, available nitrogen, available potassium and available phosphorus). Redundancy analysis (RDA) indicated the total nitrogen, available potassium and pH obviously affected some soil nematode genera. The analysis of spatial distribution characteristics of soil nematode community in farmland of Jiangsu Province could provide data for health assessment of agricultural ecosystems.