水稻田土—水系统中磷素行为及其环境影响研究

土壤测试表明供试土壤已富P．大田试验结果表明，P肥投入提高了土壤树脂P和田面水总P水平，且两者随着时间的推移而下降，但施P后的20d内，有机无机配施P肥对土壤有效P的贡献大于单施化肥P，在施P第7天时，有机无机配施P的田面水总P水平是单施化肥P的3．4倍，是施P量2倍的处理III的2．8倍，与有机肥配施的处理，其田表水P素流失潜能较单施化肥大，经33d后，P肥结构对田面水P素的影响不明显，两次水稻季节性排水而导致的P素净流失负荷和P素表观流失率变幅分别为－0．039－0．076kg.hm^-2和0.034-0.100% ,从减少水稻田排水P素流失角度考虑，可以认为，施P或土层被搅动后1周内是控制P素流失的主要环节。

Phosphorus behavior in soil-water system of paddy field and its environmental impact.

A field experiment with rice showed that P fertilizer application increased the concentrations of resin P in soil and total P in soil surface water, and both of them declined subsequently over time. Compared with applying mineral P fertilizer only, the integrated application of mineral-P and manure resulted in a higher resin P level within 20 days after P application. The total P concentration in soil surface water in the treatment of integrated application of mineral-P and manure was 3.4 times higher than that in the treatment of mineral-P fertilizer application only after 7 days of P application, and also, was 2.8 times higher than that in the treatment where P application rate was doubled. The potential of Ploss from surface water in the treatment of integrated application with manure was more than that in the treatment of applying-P fertilizer only. The effect of applied P sorts on P concentration in soil surface water could be ignored after 33 days of P application. Two drainages were conducted for rice growth, which caused the net P loss loading and its apparent P loss ratio in range of -0.038-0.076 kg.m-2 and 0.034-0.100%, respectively. To minimize P loss from rice production area, field drainage should be avoided in the initial week of P-fertilizer application or field harrowing.