施硅条件下不同有机酸对土壤磷吸附解吸的影响

摘要

采用室内培养和恒温批处理平衡方法，研究了在施加硅酸钙前提下，2 mmol /L 柠檬酸、乙酸和草酸对磷素在棕壤中吸附和解吸的影响，并用 Langmuir 方程进行拟合分析。研究结果表明，Langmuir 方程的拟合效果很好；加硅酸钙和2 mmol /L 草酸处理，以及硅酸钙和2 mmol /L 乙酸处理对磷在棕壤中的吸附量最大，均为526 mg /kg；硅酸钙和2 mmol /L 柠檬酸处理对磷在棕壤中的解吸量及解吸率最大。因此，硅酸钙＋2 mmol /L柠檬酸处理活化棕壤中磷的能力最强。%Laboratory experiments with different kinds of treatments on texted brown soil,namely original soil+ calcium silicate (CaSiO3 ),original soil +2 mmol /L citric acid +CaSiO3 ,original soil +2 mmol /L ace-tic acid +CaSiO3 and original soil +2 mmol /L oxalic acid +CaSiO3 ,were conducted to investigate the char-acteristics of soil phosphorus (P)adsorption and desorption in the presence of organic acid and silicon fertiliz-er by Langmuir equation fittings.The OECD Guideline106 batch equilibrium method was used for adsorption and desorption experiments.Results showed that the brown soil P adsorption fitted Langmuir models better. The soil added calcium silicate and 2 mmol /L acetic and oxalic acids treatments had the maximums adsorbed P,with the maximum adsorption capacities of 526 mg /kg.The soil with calcium silicate and 2 mmol /L citric acid treatment had the greatest desorption rate of P.Therefore,the soil added calcium silicate and 2 mmol /L citric acid treatment had the strongest activation ability and supply capacity of P.