不同土地利用方式对根际土壤微生物数量的影响

采用微生物平皿培养和化学分析法,在鲁西南地区选取5种不同土地利用方式,分别对根际、根外土壤微生物数量与养分状况及其相互关系进行了研究。结果表明:(1)5种不同土地利用方式下,根际土壤微生物总数量明显高于根外(非根际),表现出明显根际效应;(2)根际环境对三大类微生物产生不同的根际、效应。对细菌有明显的正效应,对放线菌和真菌有正负两方面的影响;(3)鲁西南地区土壤中仍然生存着数量较多的细菌、放线菌和真菌,但各类群在根际根外土壤中的数量排序不同。根际为细菌>真菌>放线菌,根外为细菌>放线菌>真菌;(4)不同土地利用方式下土壤微生物总数量各有差异,具体表现为菜地>麦地>稻田>果园>荒草地;(5)5种土地利用方式下,土壤性质也表现出根际效应,且与微生物总数量的根际效应相一致;(6)微生物数量与土壤大多数养分含量之间存在着一定的正相关关系,即土壤微生物数量随土壤有机质含量的增加而增加。

The Effects on the Amount of Rihizosphere Soil Microorganisms in Different Use Systems

Quantity and the properties of the surface of root and rhizosphere soil sample from five different land use patterns on southwest of Shandong were studied by chemical analysis and microbial plate culture.The result indicated that:(1)The surface of root soil was markedly more favorable to microbe in five different land use patterns,which represented root domino effect.But different land use patterns produced different root domino effect;(2) There were different rhizosphere effect on bacteria,actinomycetes,and fungi in different land use systems.It had obvious rhizosphere effect on bacteria,and positive or negative effect on actinomycetes and fungi;(3)There were still relatively considerable bacteria,actinomycetes,and fungi in different vegetation soil.Bacteria were more than actinomycetes,and fungi;(4) The total number of microorganisms were different with the different land use patterns,which changed in different soil with an order: vegetable land >corn field >paddy soil> orchard >grass land;(5)Soil character also represented root domino effect,which was consistent to amount of microbes;(6)There existed a positive correlation between the most of soil character and the amount of microbes.Tt showed that high soil fertility would help the growth of microbes.