不同盐生植被类型下土壤微生物特性研究

目的]以玛纳斯河流域扇缘带为研究区,对扇缘带盐碱土上生长的盐穗木(Halostachys caspica)、白刺(Nitraria sibirica)、猪毛菜(Salsola spp.)三种植被类型下的土壤pH、电导率、有机质及微生物类群数量进行研究,以探讨在重度盐碱环境下不同植被类型对土壤微生物的数量及分布的影响.方法]综合考虑扇缘带地形及植被类型的不同,对三种植被覆盖类型下的土壤理化性质及微生物区系进行研究,并利用SPSS17.0软件对土壤各项指标进行分析.结果]三种植被类型在40 cm剖面内,土壤pH、电导率表现为:白刺＜盐穗木＜猪毛菜,土壤含水率和有机质表现为:猪毛菜＜盐穗木＜白刺,其中白刺达到最高的8.13 g/kg,土壤细菌和真菌数量分布表现为:白刺＞盐穗木＞猪毛菜,土壤放线菌表现为:盐穗木＞白刺＞猪毛菜;在立地垂直剖面上,随着土层的增加,土壤细菌和放线菌递减,且主要分布在表土,而土壤真菌递增(除白刺外).相比空裸地,40cm剖面内三种植被覆盖类型下的土壤有机质、土壤细菌和放线菌均显著提高,土壤有机质分别提高了55.77;、99.75;和15.72;;土壤细菌分别提高了62.43;、88.48;和21.99;;土壤放线菌分别提高了91.2;、73.44;和13.71;.结论]扇缘带不同盐生植被类型下的土壤微生物区系无论是水平方向还是垂直剖面均呈现显著差异性;三种植被类型下土壤细菌数量均显著高于土壤放线菌和真菌,表明土壤细菌是盐碱土土壤微生物活动的主体;相比空裸地,盐碱土上生长的耐盐盐生植物显著改善了土壤质量,为垦区生物改良盐碱土提供了理论基础.

Study on Soil Microbial Properties under Different Halophytes Types

【Objective】In this study,soil pH,Ec,organism matter content and the quantitative characteristics of soil microorganism of Halostachys caspica,Nitraria sibirica and Salsola spp.in the alluvial fan area of Manas River watershed were analyzed so as to discuss the effects of different vegetation types on the quantity and the distribution pattern of soil microorganism.【Method】Considering landforms and different vegetation types in the alluvial fan area of Manas River watershed,soil physicoch emical properties and soil microflora under the three main vegetation types were investigated,and SPSS17.0 was used to conduct analysis of soil indicators.【Result】Soil indicators under the three main vegetation types in 40 cm depth soil profile showed that: soil pH and Ec presented Nitraria sibiricaHalostachys caspica>Salsola spp.,soil actinomycetes presented Halostachys caspica>Nitraria sibirica>Salsola spp.;In the vertical distance of soil profile,soil bacterium and soil actinomycetes showed gradual decreased with the increase of soil depth,and moreover,they are mainly accumulated in topsoil,in contrast,soil fungi showed increase(except for Nitraria sibirica).Compared to the uncovered ground,soil organism matter content,soil bacterium and soil actinomycetes of the three main vegetation types in the 40cm depth soil profile showed significant increase,the average organic matter content increased respectively by 55.77%,99.75% and 15.72%;soil bacterium increased respectively by 62.43%,88.48% and 21.99%;soil actinomycetes increased respectively by 91.2%,73.44% and 13.71%.【Conclusion】Whether horizontal or vertical profiles,soil microflora under different halophytes types showed significant differences in the alluvial fan area of Manas River watershed;quantity of soil bacterium in the three vegetation types were significantly higher than that of soil actinomycetes and fungi,it was shown that soil bacteria is the main body of microbial activity in the saline-alkali soil;Compared to the uncovered ground,the different halophytes growing on the saline-alkali soil in arid desert areas significantly ameliorate the soil quality,so the study provide the basic theory with biotic reclamation of saline-alkali soil for agricultural region.