有机磷在调节土壤磷素保持与释放过程中的作用

Roles of Organic Phosphorus in Modifying Phosphorus Sorption and Release in Soils

以巢湖沿岸土壤和沉积物为对象,分析了速效磷、藻类可利用性磷、有机磷含量和碱性磷酸酶活性的空间变化格局,并测定了磷吸附参数。结果表明,土壤有机磷含量差异显著,以草地最高,而速效磷和藻类可利用性磷含量无明显差异;酶活性及速效磷含量与有机磷含量呈显著正相关,土壤对正磷酸根的吸附量与土壤中有机磷含量呈正相关;湖泊沉积物中有机磷含量与周边土壤中有机磷含量显著正相关。因此,土壤有机磷及其酶促水解过程是调节沉积物作为磷源或磷汇功能的关键因素之一。

Spatial variations in contents of Olsen-P, algae available phosphorus （AAP）, organic phosphorus （OP） and alkaline phosphatase activity （APA） were studied in soils and sediments along shoreline of a Chinese large shallow lake （Lake Chaohu）. Phosphorus sorption behaviors fitted the Langmuir and Freundlich models well. The Olsen-P and AAP were less variable, while the OP contents were highest in grassland among all the land use types. Furthermore, the OP exhibited significantly positive correlations with both APA and Olsen-P. Additionally, the OP linearly gave rise to maximum phosphorus sorption capacity. The soils could provide the lakes with OP, as implied by the significantly positive correlation between OP contents in the soils and in the littoral zone sediments. Hence, the OP and its enzymatic hydrolysis in soils can shift sediments＇ function to act as source or sink of phosphorus.