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运用分形模型,研究了川南坡地及其退耕成慈竹林、杂交竹林、桤木+慈竹混交林和弃耕地5年后土壤团粒结构分形维数,探讨了分形维数与土壤理化性质之间的关系.结果表明:退耕后,不同退耕模式样地>0.25mm的土壤团聚体和水稳性团聚体含量均显著增加,团粒结构分形维数介于1.377～2.826,为慈竹林<杂交竹林<桤木+慈竹混交林<弃耕地<农耕地,并随>0.25mm的土壤团聚体及水稳性团聚体含量的增加而降低;土壤自然含水量、毛管孔隙、有机质、全氮、碱解氮、全磷和全钾含量增加,而土壤容重、非毛管孔隙和通气度降低.退耕后的慈竹林、杂交竹林、桤木+慈竹混交林和弃耕地的土壤团粒结构分形维数与土壤理化性质相关性较好.农耕地退耕对增加>0.25mm的土壤团聚体及水稳性团聚体含量和提高土壤结构稳定性具有较好的作用;土壤团粒结构分形维数可以作为坡地退耕后土壤肥力变化的理想指标,在研究区坡地退耕种植慈竹具有较好的培肥改土效益.
Using fractal model, the fractal dimension of soil aggregate structure in the slope land and its rehabilitated cultivated land in the south of Sichuan Province for five years was studied, and the relationship between fractal dimension and soil physical and chemical properties The results showed that the contents of aggregates and water-stable aggregates of soil aggregates and water-stable aggregates> 0.25 mm increased with the removal of cultivated land, and the fractal dimension of the aggregates was between 1.377 and 2.826. Mixed forest of mixed forest of Cinnamomum-kuhei-bamboo forest 0.25mm soil aggregates and water-stable aggregates content; soil natural water content, capillary porosity, organic matter, total nitrogen, , Total phosphorus and total potassium content increased, while soil bulk density, non-capillary porosity and aerenchy rate decreased.The fractal dimension of soil aggregate structure and the physico-chemical properties of the soil after the conversion of Cz’zhulin, Hmong bamboo, Alnus cremastogyne mixed forest and abandoned farmland And the correlation of nature was better.Reduction of farmland had a good effect on the content of soil aggregates and water-stable aggregates and the stability of soil structure with the increase of> 0.25mm.The fractal dimension of soil aggregate structure could be used as soil Soil fertility changes in the ideal indicators, the study area slope farmland planted Tsz Zhu has better soil improvement benefit.