塔里木盆地南缘绿洲农田土壤粒径分布分形特征及影响因素研究

Fractal dimension of particle size distribution and its affecting factors in oasis farmland soils in southern marginal zones of Tarim Basin

本文以塔里木盆地南缘策勒绿洲为例,基于农田表层土壤样品的体积粒径分布数据,通过分形理论重点探讨绿洲农田这一主要土地利用类型下土壤粒径分布特征及变异状况,并根据粒径分布分形维数变化对其主要影响因素进行研究。结果表明:绿洲范围内农田土壤分维值存在显著性差异,其值介于2.11～2.27之间,总体偏低;土壤粒径分布分维值与小于50μm粒径土壤颗粒体积含量及土壤有机质含量呈显著正相关;农田利用年限的差异性对土壤粒径分布产生重要影响,而农田分布位置的差异性则对土壤粒径分布未体现出规律性影响。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提高。

This paper presents a case study emphasizing the variations in particle size distribution （PSD） characteristics and its influencing factors in Cele Oasis farmland soils in the southern rim of Tarim Basin, Xinjiang, China. The results show significant difference in fractal dimensions （D） of farmland soils in the oasis. D is generally low and varies within 2.11～2.27 range. There exists a significant positive correlation between D and volume content of soil particles 50 μm on the one hand, and between D and soil organic matter content on the other. Whereas the duration of farmland cultivation importantly influences soil PSD, no consistent relation exists between locational distribution of farmland and soil PSD. These results suggest that longterm and appropriate tillage management of farmlands could have such beneficial effects as conserving and improving soil PSD.