新疆绿洲农田土壤盐碱斑特征分析

发布时间：2018-11-08 11:13

【摘要】：本文以玛纳斯县农田盐碱斑为研究对象,通过对43个盐碱斑的野外调查采样和室内分析,探讨了农田盐碱斑内外土壤剖面盐分特征、斑块效应、土壤质地和土壤pH值的研究,取得了如下结果:(1)盐碱斑的形成与盐分相关的占所调查总样点数的51.2%,按照斑心土壤表层盐分含量将盐碱斑划分为轻度、中度、重度以及盐土4种盐渍化类型。盐碱斑从斑心向外盐分含量差异显著(P0.01),即斑心边缘外部。在土壤剖面上,重度盐渍化和盐土类型的盐碱斑盐分表聚特征最明显(0-10 cm),而中度盐渍化盐碱斑土壤盐分积累区下降至10-20 cm,轻度盐渍化盐碱斑盐分在剖面上分布相对均一。盐碱斑的斑块效应从斑内向斑外总体上呈减小趋势,而同一采样部位不同盐渍化程度的盐碱斑的斑块效应差异不显著。(2)各盐渍化程度的盐碱斑土壤粉粒百分比均大于砂粒和黏粒,不受盐分影响的斑块土壤剖面的颗粒组成变化不明显,该类斑块质地类型主要为粘壤土,轻、中、重、盐土粉粒的平均含量所占的比例超过了50%,重度盐渍化盐碱斑粉粒百分比达到了62.64%,砂粒相对逐渐减小。(3)各盐碱斑土壤pH值均8,重度盐渍化的盐碱斑土壤pH值最大,轻度盐渍化和中度盐渍化程度的盐碱斑土壤pH值最小;变异系数较小,属于弱变异和中等变异水平,最大变异系数仅为最小变异系数的1.43倍,在所有盐渍化程度类型的盐碱斑剖面土壤pH变化幅度均不大。各盐渍化程度盐碱斑盐分与质地的相关性为:从砂粒、粉粒到粘粒相关性依次从显著负相关到显著正相关,各盐渍化程度盐碱斑盐分与土壤p H的相关性为:轻度盐渍化盐碱斑与不受盐分影响的斑块具有相关性,即土壤质地与pH值已成为盐碱斑盐分累积的重要影响因素。研究结果可为今后以点带面地开展绿洲农田盐碱斑综合治理提供基础数据和改良思路。
[Abstract]:Based on the field investigation and indoor analysis of 43 saline-alkali spots in Manas County, the characteristics of soil salinity, patch effect, soil texture and soil pH value were studied in this paper. The results were as follows: (1) saline-alkali spots were divided into four salinization types: mild, moderate, severe and salinized soil according to the salt content in the surface layer of the soil, which accounted for 51.2% of the total number of salinized spots. The salt content of saline-alkali spots was significantly different from the center of the spot to the outside (P0.01), that is, the outside of the edge of the center of the spot. In soil profile, saline-alkali spot salt accumulation of severe salinization and saline-soil type was the most obvious (0-10 cm), and moderate salinization saline-alkali spot soil salt accumulation area decreased to 10-20 cm,). The distribution of saline-alkali spot salt in the profile of mild salinization is relatively uniform. The plaque effect of saline-alkali spot decreased from the outside of the spot. However, there was no significant difference in patch effect of saline-alkali spots with different salinization degree at the same sampling site. (2) the percentage of soil silt in different salinization degree was larger than that of sand and clay. The grain composition of patch soil profile which is not affected by salt is not obvious. The soil texture of this kind of patch is mainly clay loam, light, medium, heavy, the average content of silt in salt soil is more than 50%. The percentage of saline-alkali spot powder reached 62.64, and the sand decreased gradually. (3) the pH value of each saline-alkali spot soil was 8, and the pH value of severe salinization soil was the highest. The pH value of saline-alkali spot soil with mild and moderate salinization was the lowest. The coefficient of variation is small, which belongs to the level of weak variation and moderate variation, the maximum coefficient of variation is only 1.43 times of the minimum coefficient of variation, and the range of soil pH in all salinization types of saline-alkali spot profile is not significant. The correlation between saline-alkali spot salt and texture was: from sand, silt to clay, the correlation between saline-alkali spot salt and texture was significantly negative correlation to significant positive correlation. The correlation between saline-alkali spot salinity and soil pH in different salinization degrees was as follows: mild salinization saline-alkali spot had a correlation with patch that was not affected by salt content, that is, soil texture and pH value had become important influencing factors of saline-alkali spot salt accumulation. The results can provide basic data and improvement ideas for the comprehensive treatment of saline-alkali spots in oasis farmland.
【学位授予单位】：新疆农业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：S156.4

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