粤东小流域源头村域土壤磷状况及流失风险

摘要

[Objective] In order to provide guidance on soil phosphorus management and production practices for soil in village domain of a small watershed, the phosphorus status and leaching risk were investigated. [Method] Phosphorus content, isotherm sorption characteristics and risk of phosphorus loss potential of soils collected from Mashi Village of Shima Town of the source areas of Shima River in Xingning County in Eastern Guangdong were analyzed. [Result] The range of total soil P, available phosphorus, dissolved reactive phosphorus, bio-available phosphorus, phosphorus concentration in soil solution, and Mehlich 3-phosphorus were 180-1 130, 8.82-42.09, 1.44-3.68, 44.93-667.78, 0.27-0.49 and 6. 88 -106. 91 mg/kg, respectively. Langmuir isotherm equation was simulated well on soils in the village of the small watershed (R - 0. 651 * - 0. 995 ). The average of phosphorus staturation of soils was 18.06% , and 72. 24% of the threshold value (25% ) of soil phosphorus readily lost. DPS of 4 pieces of soils were beyond the threshold value. [Conclusion] The phosphorus leaching potential was high in soils in the village of the source areas of Shima River watershed.%[目的]调查小流域中村域土壤磷素状况及流失风险,为土壤磷素管理和生产实践提供指导.[方法]对粤东兴宁县石马河小流域源头石马镇马石村土壤的磷素含量、等温吸附特征及流失潜能(风险)进行分析.[结果]土壤全磷、速效磷、水溶性磷、生物有效磷、土壤磷溶液中磷和Mehlich 3-P含量的变化范围分别为180 ～1 130、8.82 ～ 42.09、1.44 ～3.68、44.93 ～ 667.78、0.27 ～0.49和6.88～106.91 mg/kg.土壤可用Langmuir等温方程很好地拟合(R2 =0.651*～0.995*).土壤磷吸持饱和度平均为18.06％,为容易流失阀值(25％)的72.24％,其中4个土样的DPS已超过容易流失的阀值.[结论]石马河小流域源头村域土壤磷素具有较高的流失风险.