玛纳斯河流域不同地貌和植被类型下土壤物理性质研究

目的]定量研究玛纳斯河流域(以下简称玛河流域)不同地貌类型和植被覆盖下的土壤物理性质,以期为深入研究玛河流域盐碱土改良和农业生产耕作提供科学参考.方法]综合考虑玛纳斯河流域干三角洲、冲积平原和冲积扇扇缘带三种主要地貌类型和植被覆盖的不同,对其上生长的柽柳(Tamarix ramosissima)、盐穗木(Halostachys caspica)、猪毛菜(Salsola spp.)、小叶碱蓬(Suaeda microphyll)四种植被覆盖类型下的土壤含水率、土壤容重、颗粒组成和有机质进行研究,并利用SPSS13.0软件对土壤各项物理指标进行方差分析.结果]从干三角洲到扇缘带,0 ～100 cm剖面内土壤平均含水率和有机质逐渐升高；土壤平均容重表现为干三角洲＞扇缘带＞冲积平原区；颗粒组成干三角洲砂粒含量为58.04;,达到最大,冲积平原区主要以粉粒为主,为56.21;.在立地垂直剖面上,随着土壤深度的增加,土壤含水率和容重均表现出显著性升高；土壤有机质显著性降低.相比对照的空裸地,四种植被类型在0～100 cm剖面内土壤平均含水率分别提高了19.03;、8.93;、8.20;、13.18;；土壤平均容重分别降低了13.07;、7.95;、16.48;、2.84;,平均土壤有机质含量分别提高了70.44;、39.41;、5.63;、14.05;；平均砂粒含量分别降低了35.57;、27.50;、15.97;、17.72;.结论]玛纳斯河流不同地貌和植被类型下的土壤物理性质存在在显著差异性；相比空裸地,耐盐盐生植物,可以增加植被覆盖度,提高土壤保水能力,对流域农业垦区盐碱土的改良具有重要的意义.

Study on Soil Physical Properties under Different Landforms and Vegetation Types in Manas River Watershed

【Objective】 The paper aimed to make quantitative study of soil physical properties under different landforms and vegetation types in Manas River Watershed,and provide scientific basis for the control of soil salinization and the cultivation of agricultural production of the area.【Method】Considering the three major different landforms(Dry delta,Alluvial plains and Alluvial-proluvial fan edge) and different vegetation types in Manas River Watershed,soil moisture content,particle fraction,soil bulk density and organic matter content of four main vegetation types(Tamarix ramosissima,Halostachys caspica,Salsola spp.Suaeda microphylla,)were investigated.SPSS17.0 was used to conduct analysis of variance for soil physical properties.【Result】From Dry delta to Alluvial-proluvial fan edge in 0-100cm depth soil profile,average soil moisture content and average organic matter content gradually increased;the average soil bulk density presented Dry delta > Alluvial-proluvial fan edge> Alluvial plains;in terms of particle fraction,sand content was as high as 58.04% in the Dry delta,in contras,silt content in the Alluvial plains was as high as 56.21%.In the vertical distance of soil profile,soil moisture content and bulk density showed significant increase along with the increase of soil depth.,but organic matter content showed significant decrease.Between the four vegetation types,compared with the uncovered ground,soil average moisture content of four vegetation types in the 0-100cm depth soil profile increased separately by 19.03%,8.93%,8.20%,13.18%;the average soil bulk density decreased separately by 13.07%,7.95%,16.48%,2.84%;the average organic matter content increased separately by 70.44%,39.41%,5.63%,14.05%;the average sand content decreased separately by 35.57%,27.50%,15.97%,17.72%.【Conclusion】Soil physical properties under different landforms and vegetation types were significantly different in Manas River Watershed.Compared with the uncovered ground,we can increase the vegetation canopy,increase soil water retention and reduce erosion of sand by planting salt-tolerant halophytes,and more importantly,it has great significance to improve saline-alkali soil for agricultural watershed.