重庆山地血橙园土壤粒径分形特征

Fractal Dimension Characteristics of Soil Particle-Size Distribution in a Blood Orange Orchard of Chongqing

为了定量描述重庆山地血橙园土壤粒径分形维数特征,本试验以重庆山地血橙园内血橙-红薯、血橙-花生、血橙-玉米、血橙纯林、血橙-茄子5种模式下的土壤为研究对象,通过野外调查及室内分析试验,测定了不同模式土壤的粒径分布及理化性质,计算了分形维数,探讨了分形维数与土壤粒径分布及理化性质的关系,结果表明:血橙园不同模式下土壤质地可分为砂质粘壤土和壤质粘土两类,分形维数与土壤质地具有很好的一致性;土壤砂粒与分形维数达到显著相关(p<0.05),土壤粘粒含量与分形维数达到极显著相关(p<0.01),分形维数大小首先决定于粘粒含量、其次为砂粒含量和粉粒含量;分形维数与土壤容质量、毛管孔隙度呈正相关,与土壤pH值呈极显著正相关(p<0.01),与非毛管孔隙度、总孔隙度、有机质、全氮、全磷、全钾含量呈负相关.土壤分形维数能客观表征血橙园土壤粒径分布,反映土壤肥力特征.

In order to quantitatively describe the fractal dimension characteristics of blood orange （Citrus sinensis） orchard in hilly area of Chongqing ,soil particle size distribution and physico‐chemical properties of the soil under 5 interplanting modes （blood orange‐sweet potato ,blood orange‐peanut ,blood orange‐maize and blood orange ,blood orange‐eggplant） were tested based on field investigation and laboratory a‐nalysis .The fractal dimensions were computed and the relationships between fractal dimension and soil physico‐chemical properties were discussed .The results indicated that soil texture of different types in blood orange orchard could be divided into two categories ：sandy clay loam and loamy clay ,and fractal di‐mension had the same rule as soil texture .The contents of soil sand had negative relationship with fractal dimension while contents of soil clay had a significant positive relationship with fractal dimension （p 〈0.01） .Fractal dimension was first determined by the content of clay ,and then by the content of sand and silt .Fractal dimension had significant positive relationship with pH values （p〈0.01） and had positive re‐lationship with soil bulk density and capillary porosity while negative relationship with non‐capillary poros‐ity ,total porosity ,soil organic carbon ,total nitrogen ,total phosphorus and total potassium .In conclu‐sion ,soil fractal dimension can objectively characterize blood orange orchard soil particle size distribution and reflect the characteristics of soil fertility .