杭州市城市和郊区表土磷库及环境风险评价

杭州市城市和郊区土壤磷素具有明显的积累特征并有较高的潜在释放能力。可提取态P(包括H2O-P、NaHCO3-P.NaOH-P和HCl-P)平均在80％左右，其中以HCl—P的比例最高，平均约55％。32个研究土样中，26个土样的水可溶性(H20—P)在10mg／kg以上，15个土样的NaHCO3—P在100mg/kg以上。酸性条件下P的释放潜力明显增加。土壤水溶性P含量及在酸性条件下P的释放量与土壤总P呈正相关，与土壤pH负相关。

Pools and environmental risk assessment of phosphorus in surface soils from Hangzhou urban and suburban

Both urban and suburban soils in the Hangzhou city had been accumulated to a great extent and the potential release of P has been high. Most of the P in the soils could be extracted by water, NaHCO3, NaOH and HCl with a mean extracted percentage of 80%. The mean percentage of HCl-P in the total P was as high as 55%. Among the 32 surface soil samples, 26 soil samples had H2O-P higher than 10 mgkg-1, 15 soil samples had NaHCO3-P higher than 100 mgkg-1. The potential release of P under the acidic condition increased obviously. Water-soluble P and P released under the acidic condition increased with soil total P and decreasing soil pH.