【摘要】 为揭示不同种植年限土壤磷的固定和释放机制,通过土壤磷的等温吸附、解吸试验研究种植年限分别为3～5年、15～20年、25～30年的黄棕壤0～5cm和5～20cm土层磷的吸附、解吸特性。结果表明:土壤磷的等温吸附曲线、吸附量-解吸量曲线分别与Langmuir方程(R2为0.8728～0.8436)、二次函数方程拟合良好(R2为0.9545～0.9970);随蔬菜种植年限延长,表层土壤磷最大吸附量(Qm)、磷最大缓冲容量(MBC)明显降低,而土壤磷吸附饱和度(DPS)和解吸率明显提高;种植年限15～20年、25～30年土壤磷的解吸率明显高于3～5年土壤。对表征土壤磷素吸附、解吸特性的主要因子如MBC及DPS等作相关分析发现,无定形铁铝含量的变化是影响土壤磷吸附解吸特性的主要因素。更多还原

【Abstract】 An experiment involving 3～5, 15～20 and 25～30 years continuous vegetable cultivation was carried out to determine fixation and release mechanisms of soil phosphorus in cultivated yellow brown soils. Based on the results, phosphorus isothermal adsorption and adsorption-desorption curves are respectively described by Langmuir equation and quadratic equation. With increas-ing years of cultivation, the maximum phosphorus adsorption (Qm) and maximum buffer capacity (MBC) of surface soil decrease significantly. However, degree of phosphorus saturation (DPS) and phosphorus desorption rate increase. Phosphorus desorption rates in 15～20-and 25～30-year cultivated vegetable soils are significantly higher than that in the 3～5-year cultivated vegetable soils. Cor-relation analysis for the main factors affecting soil phosphorous adsorption-desorption (e.g., MBC, DPS, etc.) reveals that soil amor-phous Fe-Al content significantly affects soil phosphorus adsorption-desorption.更多还原