土固定铵动力学的研究

Kinetics of Ammonium Fixation in Manured Loessial soil

采用传统的振荡平衡法探讨土耕层和粘化层土样固定铵的动力学特性。结果表明，Ｅｌｏｖｉｃｈ和一级扩散动力学方程最适于描述铵固定动力学特性，表现在相关系数ｒ值大，标准误（ＳＥ）小；抛物扩散律能较满意的描述实验数据，表明铵固定属扩散控制过程。根据实验数据分别建立了不同温度、铵浓度、土样的动力学方程。由动力学一级方程确定了固铵速度常数和固铵半时值。并讨论了时间、介质温度、铵数量、粘粒数量对土壤固铵的影响。

The Kinetics of ammonium fixation in manured loessial soils were dis-cussed using Batch eauilibrium method.The results indicated that both Elovich andfirstorder equation were the most adaptable to describing the NH-4￣+ -fixation kinetics bestas avidenced by the highest correlation coefficient(r)and the lowest value of the stan-dard error of estimate(SE).The parabolic diffusion law can also describe the experi-mental data satisfactorily,thus,indicating NH_4￣+ fixation being diffusion controlled pro-cess.The Elovich and first order diffusion equations of ammonium fixation in thick andthin NH_4 CI solution addition under different temperatures for each soil sample were es-tablished.NH_4￣+ soil fixation k_f and t_(1/2) were calculated according to the first order equa-tions,The effect of factors including fixation time,temperature,NH_4￣+ concentrationand clay amounts on the NH_4￣+ fixation was also discussed.