【摘要】 通过向水稻土中加入不同量的磷(水土比为20∶1)进行培养,并利用连续提取法,对水稻土磷的固定和释放特性进行了研究。结果表明,在磷的固定研究中,随着外源磷加入量的增加,磷的固定量增加,固定率下降。在磷的释放研究中,随着提取次数的增加,磷的释放量减少,并在提取8次后,以后各次磷的释放量不发生显著变化。水稻土最大释放量和总释放量分别为91.36、206.02mg·kg-1(1.6mmol·L-1P处理)和124.07、271.91mg·kg-1(2.4mmol·L-1P处理)。磷的释放率随着提取次数的增加而增加,并逐渐达到平衡,1.6mmol·L-1P处理土壤磷的释放率高于2.4mmol·L-1P处理土壤。通过比较曲线拟合决定系数(R2),发现描述磷的释放动力学的方程拟合效果表现为Elovich方程(ET)>TowConstant方程(TC)>Parabolic扩散方程(PD)>零级反应方程(Z)>一级反应方程(F)>二级反应方程(S)。更多还原

【Abstract】 In this experiment, phosphorus fixation and release characteristics were studied with added different concentrations of P (water∶soil is 1∶20) and sequential extraction. The results showed that, amounts of fixed P increase and ratio of fixation P decrease with increase of added P. In release experiment, released P reduce with increase of number of extractions,and change insignificantly after 8 of extraction. The maximum and total amounts of released P of paddy soil are 9136, 20602(16 mmol·L-1 P treatment), and 12407 mg·kg-1, 27191 mg·kg-1(24 mmol·L-1 P treatment).The ratio of P release increase gradually and reach equilibrium with increase of number of extractions.Ratio of P release of soils treated with 16 mmol·L-1 P is higher than that of soils treated with 24 mmol·L-1 P in paddy soil.By comparing coefficients of determination (R2) for soil treated with 16, and 24 mmol·L-1 P concentrations, the order of fitness of different equations followed as ET＞TC＞PD＞Z＞F＞S.更多还原