磷肥和有机肥对不同磷水平土壤磷吸附-解吸的影响

Effect of phosphate fertilizer and manure on properties of phosphorus sorption and desorption in soils with different phosphorus levels

采用培养试验结合Langmuir吸附等温方程进行拟合求出吸附、解吸的相关参数的方法,研究了磷肥和有机肥对不同磷水平土壤磷吸附和解吸特性的影响。结果表明,随土壤磷水平和磷肥和有机肥用量的增加,土壤最大吸磷量、土壤磷最大缓冲能力显著降低;土壤易解吸磷和土壤磷的解吸率显著增加。土壤易解吸磷和土壤磷的解吸率与土壤Olsen-P呈显著正相关;土壤最大吸磷量、土壤磷最大缓冲容量与土壤Olsen-P呈显著负相关。单位量磷肥所增加的土壤易解吸磷随着磷肥用量和土壤磷水平的增加而增大;土壤磷水平和磷用量是影响土壤磷最大吸磷量和土壤磷最大缓冲能力的重要因素。

The effect of phosphate fertilizer and manure on properties of phosphorus sorption and desorption was studied on soils with different phosphorus levels. Parameters of sorption and desorption were obtained from Langmuir isotherm by incubating experiment. The results showed that maximum P sorption （Qm） and max buffering capacity （MBC） of soil phosphorus were decreased while readily desorbable phosphorus （RDP） increased with the increase of soil phosphorus levels. Qm and MBC of phosphorus in soil were decreased while readily desorbable phosphorus and desorption ratio were increased in soils after applying phosphate fertilizer and manure. Olsen-P had positive correlation with readily desorbable phosphorus and desorption ratio, but negative correlation with Qm and MBC. The main conclusions were that readily desorbable phosphorus could be increased by increasing phosphate fertilizer or soil phosphorus levels. The MBC of soil phosphorus was decreased while phosphorus desorption rate increased with increasing rate of phosphate fertilizer and manure. The Qm and MBC were mainly effected by soil phosphorus levels and application rate of P.