干旱区沙地长期培肥对土壤线虫群落特征的影响

Responses of Soil Nematode Communities to Long-term Fertilization in a Arid Region of China

为了研究干旱区沙地长期培肥对农田土壤线虫群落结构的影响,通过定位实验设计5种培肥方式,采集分析土壤样品中的线虫群落组成特征。实验中共捕获线虫18 337条,归属22科30属。群落分析结果表明,施用有机肥促进线虫总数中植物寄生线虫(PP)比例的增加,瓦斯乐斯卡指数(WI)在M3处理中最低为0.98±0.22,有机肥增加了土壤线虫群落的物种多样性和营养类群多样性;长期施用化肥能够抑制植物寄生线虫(PP),提高食细菌线虫(BF)和食真菌线虫(FF)在线虫总数中的比例,瓦斯乐斯卡指数(WI)在NPK3处理中最高为2.51±1.12,化学肥料降低了线虫群落的物种多样性和营养类群多样性,辛普森指数(Dom)和营养类群指数(TD)分别在NPK3处理中达到最低值0.13±0.01和2.34±0.07。线虫区系分析结果表明,合理的有机-无机肥配施有利于农田土壤生态系统的稳定健康发展。本研究从土壤生物学角度揭示了不同施肥措施对农田地下土壤生态过程的影响,对于保护干旱区土壤环境和农业的可持续发展具有重要意义。

An experimental platform of long-term fertilization was established in 2004 over a maize-soybean rotation ecosystem located at Linze Inland River Basin Research Station in Hexi Corridor,China,aiming at assessing the responses of soil nematode communities to different types of fertilization through five treatments.A total of 18 337 soil nematode individuals were collected,which belonged to 22 families and 30 genera.Results indicated that the organic manure increased the proportion of plant-parasites nematodes in soil nematode communities,and Wasilewska index（WI） had the lowest values（0.98±0.22） in the M3 treatments,and there were more species and trophic diversities in the organic manure treatments.Synthesis fertilizer suppressed the number of plant-parasites nematodes and increased the proportions of Bacterivores and Fungivores,and WI presented the highest values（2.51±1.12） in the NPK3 treatments,and the Dominance diversity（Dom） and trophic diversity in the NPK3 treatments had the lowest values of 0.13±0.01 and 2.34±0.07,respectively.The nematode faunal profiles revealed that the appropriate organic and chemical fertilization composition would be favor to development of a healthy and stable soil ecosystem.Nematode faunal analysis was found to be a useful method for interpreting the effects of long-term fertilization on the below-ground soil food web in an arid region.