摘要
本文采用好气培养－间歇淋洗法研究了塿土耕层土壤固定态ＮＨ的释放。实验在恒温下共培养２０周。结果表明，一级扩散动力学方程描述固定态ＮＨ的释放最好，其相关系数ｒ最大，标准误ＳＥ最小。抛物扩散方程也能较好的描述实验数据，表明固定态ＮＨ释放是一扩散控制过程，Ｅｌｏｖｉｃｈ方程的拟合情况和抛物扩散方程相同，零级方程略差，其ＳＥ较大。Ｓ１１和Ｓ１２土样固定态ＮＨ释放速度常数ｋｒ分别是０．１０９７和０．８８３４／周，最大释放ＮＨ是分别为９８．４２和８５．２５ｍｇＮ／ｋｇ，释放ＮＨ半时值分别是６．３２和７．８５周。
The kinetics of fixed ammonium release from plough layer of manured loessial soil (expressed as S11) and the soil where organic matter (OM.) was destroyed by oxidation (as S12)in Shaanxi Province of China were investigated using aerobic incubation-intermittent leaching method. The incubation was lasted up to 20 weeks to reach the maximum NH release.The kinetics of fixed NH release were evaluated using the Elovich, parabolic diffusion law,first-order diffusion and zero-order equations. The first-order equation described the NH-release kinetics best as evidenced by the highest correlations coefficient (r) and the lowest value of the standard error of the estimate (SE). The parabolic diffusion law also described the data satisfactorily, indicating that fixed NH release was a diffusion-controlled process. Although the Elovich equation was also suitable to fit the NH-release, the zero-order one was not as good as above ones, as shown by higher SE values than those found with the other equations. fixed NH-release rate coefficient (kr) was 0. 1097/week and 0.08834/week, and maximum NH-release amount 98.42mgN/kg soil and 85.25 mgN/kg soil as well as the half time values of NH-release (t1 /2)6.32 weeks and 7.85 weeks for S11 and S12 respectively. Both nitrification and soil organic matter affected fixed-NH release.
出处
《土壤学报》
CAS
CSCD
北大核心
1996年第3期287-292,共6页
Acta Pedologica Sinica
关键词
固定态
NH^+4释放
一级扩散动力学
Elovich方程
Fixed-NH_4￣+ release, First-order diffusion kinetics, Diffusion-controlled process, Elovich equation
