绿洲农田土壤粒径分布特征及其影响因素分析--以策勒绿洲为例

Characterizing Soil Particle-size Distribution and Its Variation in Farmland of Oasis——A Case Study of Cele Oasis

以塔里木盆地南缘策勒绿洲为例,重点探讨了绿洲农田土壤粒径分布特征及其主要影响因素。基于2008年9月对策勒绿洲范围内农田表层土壤粒度测定数据,首先通过土壤粒径分布体积分形维数分析,表明绿洲农田土壤粒径分布差异性显著,并根据分析结果提出假设,认为农田利用年限及空间位置的不同是土壤粒径分布产生差异性的主要因素;其次利用排序方法对影响因素的贡献率进行定量分析,并与分维值结果进行相互验证。研究结果表明在影响土壤粒径分布差异性方面,利用年限为主导因素,其相对贡献率达67%。因此,保证农田长期合理的耕作管理方式将有助于土壤粒径分布属性的稳定及改善。

In this paper, the Cele oasis, which located at the southern margin of Tarim Basin, was selected as a study area in order to analyze the farmlandsoil particle size distribution （PSD） and its variation characteristics, and then to identify the main factors that influence soil PSD. Based on soil samples collected from farmlands of whole oasis in September 2008 and the PSD data obtained by laser diffraction technique, the volume fractal dimension （D） values of soil PSD were determined. The results of D value indicated that there was significant difference in PSD between farmlands, and the hypothesis that the location and utilization year of farmlands are the main reasons that result in variation of PSD was established. The ordination methods were used to quantitatively analyze the contribution rate of each factor. Our results indicated the utilization year is the dominated factor, its relative contribution is 67%. These results indicated that long-term and effective tillage management for farmlands will be beneficial to keep and improve states of soil PSD.