磷在红壤肥际微域中的迁移和转化

Movement and Transformation of Phosphorus in Fertilizer Microsites in Red Soil

采用室内土柱实验研究了磷在红壤肥际微域中的迁移和形态转化。结果表明,相同施量的磷在7天和28天时的迁移距离相同,施用磷酸二氢钙(MCP)0 2g和0 5g时的迁移距离分别为1 4cm和2 0cm。磷在施肥7天内的迁移量较大,然后只发生少量迁移。迁移进入土壤的磷86 3%～94 2%被吸附固定,64 1%～72 2%仍以有效态存在。在迁移距离内,土壤水溶性磷、酸溶性磷和有效磷含量与距施肥点距离呈极显著直线负相关。施肥量对水溶性磷、酸溶性磷和有效磷在肥际微域中的含量分布有显著影响;但培养时间只对水溶性磷含量分布有显著影响。

In this paper, the movement and transformation of phosphorus (P) in fertilizer microsites in red soil were studied by an incubation experiment using soil column. The movement distances of added P were the same at both 7 day and 28 day, 1.4 cm for MCP 0.2 g and 2.0 cm for MCP 0.5g. Most of P moved into soil was absorbed but still in available form in fertilizer microsites. The concentrations of water-extractable P, acid-extractable P and available P have significant negative linear relationships with distance from fertilizer placement in the region of P movement. The amount of P application has significant effects on the concentration distributions of water-extractable P, acid-extractable P and available P in fertilizer microsites. However, incubation time has significant effect on only water-extractable P.