滴灌施肥条件下红壤中磷的分布特征

采用模拟滴灌施肥方法袁研究了200mg/L和500mg/L KH2PO4两种滴施磷肥浓度条件下磷素在红壤中的有效性及分布规律。结果表明，施肥浓度对全磷和有效磷在土壤剖面中的分布均有影响，随着距滴头距离的增加，全磷含量呈相对均匀的速率降低，而有效磷呈先快后慢的速率降低；高浓度施肥有利于磷素向距滴头更远处移动，且有助于提高土壤中有效磷含量遥因此袁滴灌施磷时建议采用较高磷浓度施用遥

Phosphorus distribution in red soil with drip fertigation

By the method of simulating fertigation, the availability and distribution of phosphorus was studied when KH2PO4 was fertilized with the concentrations of 200 mg/L and 500 mg/L. The results showed that the distribution of total phosphorus and available phosphorus in the soil profile were effected by fertilizer concentration. With the increase ofdistance from the emitter, total phosphorus content decreased with relatively uniform rate, while the decrease trend ofavailable phosphorus was rapid firstly and the became slow. With high concentration of phosphorus fertigating, phosphorus could move farther away from the emitter and available phosphorus content of soil also was higher. Therefore, highphosphorus concentration is suggested when phosphorus is fertilized by drip irrigation system.