土壤中积累态磷的化学耗竭

Chemical depletion of cumulative phosphorus in soils.

积累态P是指肥料P未被植物利用而积累于土壤中的那一部分P素 .本文用一次平衡法、流动技术法和阴离子树脂膜等不同方法来研究土壤中积累态P的化学耗竭 .研究表明 ,解吸出的P量随时间的增加而增加 ,P解吸过程符合二级动力学方程 ,各处理中P的释放过程快慢程度是PK >NPK >NK ,红壤的释放量和释放速度均比潮土的要大且快 .解吸P量与土壤速效P和植物吸收P均有显著相关 .土壤中积累态P最大表观利用率为总P量的 4 5

Cumulative phosphorus was defined as the phosphorus which was unavailable for plants and accumulated in soils fertilizer application. In this paper, chemical depletion of cumulative phosphorus in soils was studied by methods of batch equilibrium, kinetic, and anionic exchange resin membrane. The results showed that desorption amount of cumulative P increased with time increasing, and the desorption process was consonant with second order kinetic equation. Release rate of P in different treatments was in order of PK>NPK>NK. The amount and rate of P released from red soil were higher than those of Fluvio aquic soil. Desorbed P was significantly correlated with soil available P and P uptake by Plant. The maximum utilization of cumulative P in soils was about 45% of total phosphorus.