优化施肥对设施蔬菜地土壤线虫群落的影响

高强度利用下设施蔬菜地的施肥过量问题导致了土壤质量的严重退化,合理施肥是维持蔬菜地生产力和可持续发展的重要措施.本研究比较了常规施肥和优化施肥两种施肥方式下连续种植番茄和辣椒后土壤理化性质、线虫群落及蔬菜产量的差异.结果表明: 优化施肥处理土壤pH显著高于常规施肥处理,且番茄和辣椒产量分别提高了9.0%和6.9%.与常规施肥相比,优化施肥提高了土壤线虫数量和食细菌线虫的相对多度,但降低了食真菌线虫和植食性线虫的相对多度.两季蔬菜种植过程中,不同施肥处理土壤寄生线虫成熟指数、多样性指数和丰富度指数无显著差异.优化施肥土壤线虫通路比值(0.67～0.84)显著高于常规施肥(0.39～0.64),前者土壤食物网的分解途径以细菌为主,而后者则为真菌控制.综合土壤理化性质、线虫数量和群落及蔬菜产量指标,优化施肥措施能够在促进蔬菜生长的同时,显著改善土壤生态环境.

Effects of optimized fertilization on nematode community in greenhouse soils

Excessive fertilization easily leads to the degradation of greenhouse vegetable fields, therefore rational fertilizations are important to maintain the production and sustainable development of vegetable. In this study, two fertilization treatments (optimized fertilization and conventional fertilization, noted as OF and CF, respectively) under continuous tomato-pepper cropping were arranged to investigate soil physicochemical properties, abundance and trophic groups of nematode and vegetable yield. The results showed that OF could maintain soil pH at the relatively higher level and increase the yield of tomato and pepper by 9.0% and 6.9% compared to CF treatment. In contrast to CF, OF increased nematode quantity and the relative abundance of bacterivores, but decreased the relative abundance of fungivores and plant-parasites, more obviously in the growth season of tomato. No obvious differences in plant parasite index, diversity, and richness were observed between CF and OF treatments across all sampling stages of tomato and pepper. Nematode channel ratio ranged from 0.39 to 0.64 in CF treatment, which was significantly lower than that in OF treatment (0.67-0.84), suggesting that the decomposition of food network was dominated by fungi in CF treatment but by bacteria in OF treatment. Based on soil physicochemical properties, nematode groups and vegetable yield, we concluded that optimized fertilization could not only increase vegetable growth but also improve soil ecological environment.