塿土固定铵动力学的研究

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。

Kinetics of Ammonium Fixation in Manured Loessial soil

The kinetics of ammonium fixation in manured loessial soil were diseussed using Batch eauilibrium method.The results indicated that bot hElovich andfirstord erequation were the most adaptable to deseribing the NH₄⁺-fixation kinetics bestasavideneedbythehighesteorrelationeoeffieient(r)andthelowestvalueofthestan-dard error of estimate (SE).The parabolic diffusion law can also describe the experimental data satisfactorily,thus,indicating NH₄⁺fixation being diffusion controlled process.The Elovich and first order diffusion equations of ammonium fixation in thick andthin NHNH₄Cl solution addition under different temperatures for each soil sample were established.NH₄⁺ soil fixation k_f and t_? were calculated aeeording to the first order equations.The effect of factors including fixation time,temperature,NH₄⁺ concentrationand clay amounts on the NH₄⁺ fixation was also discussed.