衬膜水稻技术对科尔沁沙地土壤线虫群落特征的影响

Effects of Film Lined Rice Technology on Soil Nematode Community Characteristics in Horqin Sandy Land

摘要: 为了分析衬膜水稻对科尔沁沙地土壤线虫群落组成与结构特征的影响，探明不同处理对科尔沁沙地土壤线虫群落组成与营养类群分布差异的成因，本研究以未修复的沙地为对照，分析了水稻田和休耕地0~10、10~20、20~30 cm土层中土壤线虫群落的变化特征。结果表明：(1) 沙地、水稻田、休耕地的线虫优势属存在差异，小杆总科(Rhabditidae)为其共同的优势属，随着水稻田和休耕地的修复，威尔斯属(Wilsonema)、前矛线属(Prodorylaimium)成为新的优势属；(2) 随水稻田、休耕地的修复，土壤线虫的总数呈先升高后降低的趋势，在0~10、10~20 cm的土层中水稻田中土壤线虫的总数与沙地、休耕地的土壤线虫的总数存在显著差异；而在20~30 cm的土层中沙地、水稻田、休耕地土壤线虫的总数之间则不存在显著差异；(3) 沙地、水稻田、休耕地土壤线虫生活史的策略在0~20 cm的土层中以c-p1为主，偏向于r对策者，而在20~30 cm的土层中，土壤线虫生活史的策略以c-p4和c-p5为主，偏向于K对策者。特别是在水稻田修复后，休耕地各土层各c-p类群线虫的相对多度相比于沙地逐渐趋于稳定，逐渐向K对策者转变，c-p4为其主要的优势类群；(4) 沙地、休耕地的土壤线虫营养类群的个体密度表现为杂食–捕食性线虫 > 食细菌线虫 > 食真菌线虫 > 植食性线虫，而水稻田土壤线虫营养类群的个体密度表现为食细菌线虫 > 杂食–捕食性线虫 > 植食性线虫 > 食真菌线虫。土壤线虫群落分布特征可以反映衬膜水稻技术对科尔沁沙地土壤微环境的变化，对土壤质量具有一定的指示作用，能够为科尔沁沙地土壤生态系统的科学管理提供理论支撑。

Abstract: In order to analyze the influence of film lined rice on the composition and structural characteristics of soil nematode community in Horqin Sandy Land, and to find out the causes of different treatments on the composition and distribution of trophic groups of soil nematode community in Horqin Sandy Land, this study took the uncultivated sandy land as a control, and analyzed the changing characteristics of soil nematode community in 0~10, 10~20, 20~30 cm soil layers of rice fields and fallow land. The results showed that: (1) There were differences in the dominant genera of nematodes among sandy land, paddy fields, and fallow land, with Rhabditidae being the common dominant genus. With the restoration of paddy fields and fallow land, Wilsonema and Prodorylaimium became new dominant genera; (2) With the restoration of paddy fields and fallow land, the total number of soil nematodes showed a trend of first increasing and then decreasing. There were significant differences in the total number of soil nematodes between paddy fields and sandy and fallow land in the 0~10 and 10~20 cm soil layers; However, there was no significant difference in the total number of soil nematodes among sandy land, paddy fields, and fallow land in the soil layer of 20~30 cm; (3) The strategies for the life history of soil nematodes in sandy land, paddy fields, and fallow land are mainly based on c-p1 in the 0~20 cm soil layer, leaning towards the r strategy, while in the 20~30 cm soil layer, the strategies for the life history of soil nematodes are mainly based on c-p4 and c-p5, leaning towards the K strategy. Especially after the restoration of rice fields, the relative abundance of nematodes in different c-p groups in various soil layers of fallow land gradually stabilized compared to sandy land, and gradually shifted towards K strategies, with c-p4 being the main dominant group; (4) The individual density of soil nematode trophic groups in sandy and fallow land is as follows: omnivorous predatory nematodes > bacterial eating nematodes > fungal eating nematodes > herbivorous nematodes, while the individual density of soil nematode trophic groups in paddy fields is as follows: bacterial eating nematodes > omnivorous predatory nematodes > herbivorous nematodes > fungal eating nematodes. The distribution characteristics of soil nematode community can reflect the changes of soil microenvironment caused by film lined rice technology in Horqin Sandy Land, have a certain indication effect on soil quality, and can provide theoretical support for the scientific management of soil ecosystem in Horqin Sandy Land.