不同植被对盐碱地土壤微生物数量及的酶活性影响

Effects of different vegetation on soil microorganisms number and enzyme activities in alkaline saline soil

以甘肃敦煌盐碱地为研究对象,在分布黑果枸杞,骆驼刺以及黑果枸杞和骆驼刺混生植被的盐碱地上选取0~20、20~40和40~60 cm土层,测定土壤理化性质、土壤酶活性、土壤微生物群落数量。结果表明:不同植被条件下土壤中Cl-含量随着土层深度增加而减少,且集中在土壤0~20 cm;电导率随着土层深度增加而减小;阴离子中Cl-含量大于SO42-,阳离子中Na+含量最大。不同植被和不同土层中细菌数量最多,真菌数量最少,放线菌数量介于细菌和真菌之间。土壤中过氧化氢酶、转化酶及碱性磷酸酶活性差异显著(P<0.05),而脲酶活性差异不显著(P<0.05)。综合分析表明该区域盐碱地土壤盐以NaCl为主,土壤微生物中细菌数量最多。

The effects of different plant communities(Lycium ruthenicum,Alhagi sparsifolia and L.ruthenicum+A.sparsifolia)growing in saline-alkali land on the soil physiochemical properties,soil enzyme activities,and soil microbial communities in 0~20,20~40 and 40~60 cm layers were studied in Dunhuang,Gansu Province.The result showed that the Cl-content decreased with the increase of soil depth,and it was mainly distributed in soil surface.Soil conductivity decreased with the increase of soil depth.Cl-content was higher than SO42-among tested anions,while Na+content was the highest among tested cations.The number of bacteria was the highest while fungi was the lowest in soil,and the actinomycetes was between bacteria and fungi,indicating that the soil microorganisms mainly were comprised by bacteria.The activities of catalase,invertase and alkaline phosphatase in soil were significantly different(P<0.05)with the exception of urease.These results indicate that NaCl is the main salt in the saline-alkali soil in this region.