长期施肥对白浆土磷吸附与解吸的影响

对白浆土在长期施肥条件下磷的吸附与解吸进行了研究。试验结果表明，供试白浆土磷的等温吸附曲线符合langmuir方程，在低磷浓度下其吸磷能力较强，随着磷浓度的增大，吸磷能力减弱。在不同施肥处理中，CK处理的最大吸附量（Xm）最大，OM处理最小，各处理吸附常数（K）值变化较小，均在0．2左右，而Xm变化较大；不同施肥处理总的解吸趋势是一致的，即解吸量随着浓度的增加而增加，而后逐步趋于平稳。施有机肥的处理土壤吸附磷能力降低，但解吸磷能力增强；长期不施肥土壤固磷能力增强。

Effects of long- term fertilization on phosphorus sorption and desorption in albic soil

In this paper, phosphorus sorption and desorption in Albic soil were studied under long- term fertilization. The results indicated that the phosphorus absorption curve of tested soil accords with the formula of langmuir. The capacity of absorbing phosphorus in low concentration was strong, but with the increasing of phosphorus concentration, that of absorbing phosphorus became week. In different fertilization treatment, the maximum phosphorus sorption in no fertilization treatment was the biggest, that of the treament of applying manure was the smallest. The change of eguilibrium constant was little, the value was 0.2 or so, that of the maximum phosphorus sorption was large. The trend of phosphorus sorption in different fertilization treatment was all that the phosphorus sorption capacity increase with the increasing of phosphorus concentration, then become steady. Applying manure made the capacity of absorbing phosphorus decline, but that of desorbing phosphorus enhancd; no fertilization made the capacity of fixing phosphorus to ascend.