水丝蚓对稻田土壤微生物的影响

通过野外采样和室内控制试验,初步研究了底栖动物水丝蚓对稻田土壤微生物(区系、生物量、生理群)的影响.结果表明,水丝蚓组稻田土壤细菌、放线菌、真菌数量均高于对照组,分别达到极显著、显著、极显著.水丝蚓组稻田土壤微生物生物量碳(BC)和生物量氮(BN)高于对照组,均达到极显著差异水平.水丝蚓促进了稻田土壤硫化细菌、硝化细菌、纤维素分解菌、氨化细菌和固氮菌的增殖,抑制了反硫化细菌和反硝化细菌的生长和活性,有利于增加土壤硫、氮、磷等生源要素的有效性,提高稻田土壤养分的利用效率.利用底栖动物的生物扰动效应,根据农业系统中不同营养级生物的生态特性,可开发多级物质循环、多层次利用、多物种共生的现代农业技术,为可持续农业提供支持.

Effects of Limnodrilus on soil microorganisms in paddy field

Through sampling in field and experiment in laboratory, the effects of benthos Limnodrilus on soil microorganisms (microflora, biomass, special physiological groups) in paddy field were preliminarily investigated. The quantities of soil bacteria, actinomycetes and fungus in Limnodrilus group were higher than those in control group, at significance level P <0.01, P <0.05, and P <0.01 respectively. The quantities of soil microbial biomass C and N in Limnodrilus group were remarkably higher than those in control group, both at significance level P<0.01. Limnodrilus promoted the multiplication of sulfur bacteria, nitrobacteria, cellulose decomposing bacteria, ammonifying bacteria, and nitrogen fixing bacteria in paddy soil, inhibited the growth and activity of sulfate reducing bacteria and nitrate reducing bacteria, which was beneficial for increasing availability of biogenic elements including sulfur, nitrogen, phosphorus, and improving the nutrient utilization efficiency of paddy soil. Using bioturbation effect of benthic animals, based on the ecological features of creatures on different trophic levels in agro-ecosystems, modern agricultural technologies for multiclassmatter cycling, multi -level utilization, multi -species symbiosis may be developed, so as to provide support forsustainable agriculture.