Abstract: Nematode has been widely used as indicative organism in the field of soil ecology, and also an important organism indicating soil health. In order to investigate the effect of continuous cropping with film mulch on soil ecosystem, this paper compared and studied the differences in soil physico-chemical properties, soil nematode functional groups and ecological indices between film mulch and non-mulch in maize fields of Chifeng, Inner Mongolia. The results showed that mulch for continuous cropping field significantly (P<0.05 or P<0.01) reduced soil moisture content, porosity, silt particle content, organic carbon, total nitrogen, total phosphorus, total potassium, available phosphorous, cation exchange capacity, and contents of sucrase, protease and urease, while soil bulk density, contents of sand and catalase significantly increased (P<0.01). Total 55 nematode genera were identified, 49 of them in maize fields with mulch, 50 in fields without mulch. In the maize fields with mulch, the quantities of bacterivores, fungivores, plant parasites, c-p1 groups, c-p2 groups were significantly lower (P<0.05) than those in maize fields without mulch. The summed maturity index (MMI), maturity index of free-living (MI) and channel index (CI) were significantly higher in film mulching maize fields than those in maize fields without mulch, While the enrichment index (EI) was significantly lower than that in maize fields without mulch, indicating that the continuous cropping with mulch had changed soil environment, reduced various soil physical and chemical indices, affected soil nematode community structure, reduced soil nematode number and composition, so soil health was deteriorated.

Key words: film mulching, nematode trophic groups, relative abundance, ecological indices

摘要： 线虫作为指示生物已被广泛应用于土壤生态学领域，成为指示土壤健康的重要生物。为了探明多年覆膜连作对土壤生态系统的影响，分析了内蒙古赤峰地区多年覆膜连作和未覆膜连作玉米田土壤理化性质、土壤线虫功能类群及生态指数间的差异。结果表明：多年覆膜连作导致土壤含水量、土壤孔隙度、粉粒含量、有机碳、全氮、全磷、全钾、速效磷、阳离子交换量、蔗糖酶、蛋白酶、脲酶含量显著（P<0.05）或极显著(P<0.01)降低，土壤容重、砂粒含量和过氧化氢酶含量极显著增加（P<0.01）。所有处理共鉴定出土壤线虫群落55个，覆膜连作玉米田49个，未覆膜连作玉米田50个；覆膜处理的玉米田中，食细菌线虫、食真菌线虫、植物寄生线虫、c-p1和c-p2类群数量均显著低于未覆膜玉米田（P<0.05）。覆膜连作玉米田中，总成熟度指数（MMI）、自由生活线虫成熟度指数（MI）和通道指数（CI）均显著高于未覆膜玉米田，富集指数（EI）显著低于未覆膜玉米田。这说明多年覆膜连作改变了土壤环境，使多种土壤理化指标降低，影响了土壤线虫群落结构，降低了土壤线虫的数量和组成。

关键词: 覆膜, 线虫营养类群, 相对多度, 生态指数