黑土表层土壤颗粒的分形特征

基于第二次全国土壤普查结果,应用土壤颗粒的质量分布计算了36个典型剖面表层土壤颗粒的分形维数值.结果表明:土壤颗粒分形维数值D在2.5831～2.8230,其变异性极弱,且分形维数值随质地变细而增大;土壤机械组成中,砂粒(2～0.02mm)含量、粉粒(0.02～0.002mm)含量与分形维数值均呈显著负相关(P<0.05);粘粒(<0.002mm)含量与土壤分形维数值呈极显著正相关(P<0.01);分形维数值D与土壤中的有机质、全N、全P、全K含量及pH值相关性均不显著.土壤分布的分形维数可以作为反映黑土退化程度的一个综合性定量指标.

Fractal characteristics of soil particles in surface layer of black soil

Based on the second national soil survey of China,the fractal dimension of soil particles in the surface layers of 36 typical profiles of black soil was calculated.The results showed that the fractal dimension was 2.5831-2.8230,being increased with decreasing diameter of soil texture,but the variability was inconspicuous.The fractal dimension was negatively correlated with the contents of sand(2-0.02 mm)and silt(0.02-0.002 mm)(P<0.05),but positively correlated with clay(<0.002 mm)content(P<0.01).No significant correlations were observed between soil particle fractal dimension and soil organic matter,total nitrogen,total phosphorus,total potassium,and pH.The fractal dimension of soil particles could be used as a comprehensive and quantitative index in evaluating the degradation degree of black soil.