泉州市不同利用方式下土壤磷的吸附与解吸特性

Soil phosphorus sorption-desorption characteristics under different land use in Quanzhou City,Fujian

分析了不同利用方式下泉州市土壤磷素吸附-解吸特征。结果表明:Langmuir等温方程式可以很好地表征土壤磷素的吸附特性;旱地和轮作地土壤对磷的吸附能力较强,而草地和林地土壤对磷的吸附能力较弱;磷的流失风险顺序为轮作地>草地>林地>旱地;指导施磷量与吸附常数、最大缓冲量的大小顺序一致,为旱地>轮作地>林地>草地;轮作地和草地的解吸率高于旱地和林地,土壤的缓冲能力顺序为旱地>林地>轮作地>草地。主成分分析表明,平均解吸率、易解吸磷、磷吸附指数和磷零吸持平衡浓度4个指标最能反映土壤磷素流失潜力,可作为评价流失潜力的主要指标。

Soil samples were collected from the rotation land,grassland,forestland,and dry land in Quanzhou City to study the soil phosphorus （P） sorption-desorption characteristics under different land use.Langmuir isotherm equation could well describe the soil P sorption characteristics.The soil P sorption capacity of rotation land and dryland was higher than that of grassland and forestland,and the soil P loss risk was in the order of rotation land grassland forestland dry land.The soil P sorption constant and maximum buffering capacity were in the sequence of dry land rotation land forestland grassland,and thereby,the recommended P application rate should be in accordance with the sequence.The soil P desorption rate of rotation land and grassland was higher than that of dry land and forestland,and the soil P buffering capacity was dry land forestland rotation land grassland.Principal component analysis revealed that the mean P desorption rate,easily desorbable P,P sorption index,and equilibrium P concentration could best reflect the potential of soil P loss,and be used as the main indices to assess the potential of soil P loss.