磷在潮土肥际微域中的迁移和转化

MOVEMENT AND TRANSFORMATION OF PHOSPHORUS IN FERTILIZER MICROSITES IN A FLUVO-AQUIC SOIL

采用室内土柱实验研究了磷在潮土肥际微域中的迁移和形态转化。结果表明,磷在潮土中的移动距离很短,经过7 d和28 d的迁移,磷的迁移距离仅为8～14 mm。施入的磷主要固定在紧靠施肥点2 mm土体范围内,随距施肥点距离的增加,土壤水溶性磷、酸溶性磷和有效磷的含量呈指数曲线迅速降低。磷在施肥后7 d内的迁移量较大,迁移进入土壤的磷绝大部分被吸附固定。施肥量对不同形态磷在肥际微域中的迁移量产生显著影响;但培养时间只明显影响了水溶性磷的迁移量。

Movement and transformation of phosphorus （P） in fertilizer microsites in fluvo-aquic soil were studied through an indoor incubation experiment using soil columns. Results show that fertilizer P did not move far, only 8 - 14 mm, after 7 and 28 days of transportation. Most of the applied P was fixed by the soil within the radius of 0 - 2 mm of the site of fertilizer placement. The concentrations of water-extractable P, acid-extractable P and available P decreased rapidly with the increase in distance from the site, showing an exponential curve. P movement occurred mainly within the first 7 days after application and most of the P that moved into the soil was fixed by the soil through adsorption. P application rate significantly affected the movements of various fractions of P within the fertilizer microsite, whereas duration of the incubation had significant effect only on the movement of water-extractable P.