土壤磷吸附参数及其与土壤磷的关系.docxVIP

土壤磷吸附参数及其与土壤磷的关系摘要：通过对磷(P)土壤的吸附特征及其与土壤磷(STP) 的关系的研究可以为径流可溶性磷浓度的预测提供一定的理论基础。本研究的60个表层土壤来自加拿大安大略省目的在于为安大略省提供此类信息。磷的吸附行为的特点符合Langmuir方程且可以归纳为四个吸附参数：磷的最大吸附系数(Qmax)、磷的吸附强度(PSS)、零吸附磷平衡浓度(EPC0)和最初吸附磷浓度(Q0)。PSS(r2= 0.93–0.95)、EPC0(r2= 0.42–0.82)和Q0(r2= 0.57–0.79)能够预测饱和铁氧化物地带磷、土壤有效磷含量，水提取磷和Mehlich-3 P，我们确定了在土壤地表径流DRP和EPC0低浓度(0.1mg·L-1)PSS的临界值，即有效态磷含量为30mg·kg-1时其值为0.39mg·L-1。探索两者之间的关系我们可以发现，土壤有效磷含量和EPC0之间的关系土壤与土壤有效磷含量小于30mg·kg-1将导致EPC0浓度小于0.1mg·L-1，结果表明，土壤与土壤有效磷含量大于30mg·kg-1可导致明显的径流可溶性磷流失，因此在证实源因素和运输因素集成地点磷的评估有必要采取缓解措施（如：土壤水文电导率、边坡、降水和水源的距离）。关键词：土壤磷吸附关系Phosphorus Sorption Parameters of Soils and Their Relationships with Soil Test Phosphorusabstract：Understanding phosphorus (P) sorption characteristics of soils and their relationships with soil test P (STP) may aid the prediction of runoff soluble P concentration. This study was conducted to provide such information for soils in Ontario, Canada. A total of 60 surface soil samples were collected from six major soil series in Ontario. Phosphorous sorption behaviors were characterized by a modified Langmuir equation and summarized by four sorption parameters: P sorption maximum (Qmax), P sorption strength (PSS), equilibrium P concentration at zero net sorption (EPC0), and initially sorbed P (Q0). Soil PSS, EPC0, and Q0could be predict-tedby saturated iron-oxide strip P, Olsen P, water extractable P, and Mehlich-3 P, with PSS following a power function (r2= 0.93–0.95), EPC0following a quadratic function (r2= 0.42–0.82), and Q0following a linear function (r2= 0.57–0.79). We identified a critical PSS value (i.e., 0.39 mg·L?1, corresponding to 30 mg Olsen P kg?1) above which soils had low surface runoff DRP and EPC0concentration (0.1 mg·L?1). The relationship between Olsen P and EPC0confirmed that the soil with Olsen P 30 mg kg?1would lead to EPC0concentration0.1mg L?1. The findings suggest that soils with Olsen P 30 mg P kg?1may cause significant run off soluble P loss, and thus necessary mitigation measures may need to be adopted