云南宣威市烟田耕作层土壤颗粒分形特征研究

Study on Fractal Characteristics of Tobacco Soil Particles in Xuanwei of Yunnan

在宣威市烟田耕作层土壤属性数据的基础上,研究了土壤颗粒分形维数与土壤机械组成、土壤质地和土壤养分间的关系,建立了植烟土壤颗粒分形维数的预测函数。结果表明:除了【1.0 mm颗粒含量外,土壤颗粒分形维数与低于一定粒径的颗粒含量呈极显著正相关,且测定的粒径越小,直线斜率和相关系数越大,这表明随着土粒直径减小,分形维数增加。土壤颗粒分形维数重点反映黏粒含量,其次是粉粒含量。宣威市植烟土壤质地以壤土为主,适合优质烟的种植,土壤颗粒分形维数介于2.4889~3.8905之间,土壤颗粒分形维数可作为描述土壤质地的综合性定量指标,但土壤有机质、全氮、全磷、全钾含量与土壤颗粒分形维数的单相关性均不显著。建立的植烟土壤颗粒分形维数估算函数预测准确度和精确度高,分别为0.9714和0.9617,且相对误差较低(-0.8236%~0.8208%),能很好地用于模拟植烟土壤分形维数。

Based on the soil data in Xuanwei, the relationship among soil mechanical composition, soil texture soil nutrient and soil fractal dimension were investigated. The prediction function of tobacco soil fractal dimension was established. The results showed that firstly, except < 1.0 mm soil particle, fractal dimension of soil were positively correlated with soil particle content of lower a certain size. With the decrease of the particle size, the slope and correlation coefficient increased. Moreover, with the decrease of soil particle diameter, the fractal dimension of soil increased, and vice versa. Fractal dimension of soil particle mainly reflected the content of clay, and followed by silt content. Loam soils were the majority of tobacco soil texture in Xuanwei, which were suitable for planting the high quality of tobacco. The fractal dimension of tobacco soil in Xuanwei ranged from 2.4889 to 3.8905. The finer was the soil texture, the larger was fractal dimension of soil, and vice versa. Fractal dimension of soil could be used as a comprehensive quantitative index to describe the soil texture. The model of soil fractal dimension could be used for a good simulation of fractal dimension with high accuracies(0.9714), high precision(0.9617), and low relative error.