杉木连栽林地土壤微生物区系及其生化特性和理化性质的研究

Study on Soil Microbiota and its Biochemical Properties and Physical Chemistry Droperties of Cunninghamia lanceolata Succession Cultivation Stand

选择立地坏境条件相同的杉木连栽与头栽林地，进行土壤微生物，酶活性及理化性质的分析。研究表明，杉木连栽林地土壤微生物总数下降２３．３５％，其中细菌、放线菌分别下降２４．７９％和３４．０４％，真菌增加１０．３９％微生物主要生理类群氨化细菌、纤维素分解菌、好气固氮菌、微嗜氮菌分别下降３６．６０％、１４．２４％、５６．５６％和２５．８１％，厌气固氮菌增加４６．１５％．连栽林地土壤的脲酶、转化酶、过氧化氢酶的活性明显低于头栽土壤、多酚氧化酶则相反。在０－４０ｃｍ土层中．同于连栽引起土壤容重增加２．５９％、毛管孔隙、毛管含水量、田间持水量和自然含水量分别下降８．４６％、１１．０４％、１１．７８％和７．０８％，土壤有机质、Ｎ、Ｐ全量分别下降１６．６１％、１２．７５％和２１．４９％．Ｎ、Ｐ、Ｋ速效养分含量分别下降２０．０８％、８．７８％和２４．８５％．因而提出营造混交林，发展林下植被，停止或减少炼山和全垦以及增加肥料投入等技术对策。以防止连栽引起的地力衰退。

Study on soil microbe enzyme activity and physical chemistry properties of Cunninghamialanceolata and succession cultivation stand under same site conditions showed that total amount of soil microbe in succession stand decreased by 23.35%,mactivity of urease invertase and catalase in succession stand was evidently lower than in first stnd,but polyphenol oxidase on the contrary.Because of succession cultivation,soil apparent density increased by 2.59%,capillary pore,capillary moisture content,field water-holding capacity and natural moisture content decreased respectively by 8.46%, 11.04% 11.78% and 7.08%.soil organic matter,N,total P decreased by 16.61%, 12.75% and 21.49%. Active N、P、K、also decreased by 20.08%,8.78% and 24.85%.Therefore,cultivation of mixed forest,development of undergrowth,decrease or even stop of reclamation,increase of fertilizer imput,etc were proposed for prevention of land capability degradation.