川西山地不同土地利用方式下土壤磷迁移特性研究

农用地土壤中磷的流失是非点源污染的主要来源,通过定点取样分析对比不同土地利用方式下土壤吸磷特征,以期识别不同土壤磷流失的潜在风险.研究结果表明,川西山地旱地土壤磷素水平较高,但其对磷的固定能力较差,标准需磷量最低,磷吸持饱和度和磷零吸持平衡浓度则高于其他土壤,这就决定了旱地土壤中的磷被淋溶或随地表径流流失的风险明显高于其他土壤.水田土壤对磷的固定能力很强,土壤磷含量较低,土壤磷向液相释放的风险较低,而茶园和林地土壤的磷流失风险则介于旱地和水之间.

Movement of Phosphorus in Soils Under Different Land Utilization in Mountain Regions in Western Sichuan

Phosphorus in runoff from soils under different land utilization was a major factor as agricultural non -point source pollution. In order to define potential risk of phosphorus loss, phosphorus sorption characteristics in soils under different land utilization were compared by evaluating phosphorus sorption isotherms. It was showed that risk of phosphorus loss from the dry lands via runoff and leaching were the higher than that from the other lands, because the soil in the dry lands not only had a much higher levels, but also the phosphorus sorption capacity and SPR were in the lowest, and the levels of DPS and EPCo were in the highest of all. In contrast, the potential risk of phosphorus loss from the paddy soils was much lower than that of dry lands, and the tea plantation and woodland were in intermediate level compared to either dry lands or paddy field.