摘要
用^(32)P 和^(36)Cl 标记扩散半池技术测定了陕西4种不同质地土壤在不同含水量和温度下磷、氯扩散运移的规律,并对其差异性进行了比较。结果表明,磷扩散系数(D_a)随土壤水分含量(W)增加而增大,符合幂函数 D_a=aW^b 关系,而 Cl^-扩散系数(D)随土壤水分增加近似线性;在20%含水量下,Cl^-扩散的活化能(E_a)为黄绵土>黑垆土>(土娄)土>黄褐土,而磷扩散的活化能次序与此相反,且比前者大得多。磷和氯在土壤中的扩散机理有很大的差异,这种差异主要归因于土壤与磷、氯离子之间相互作用的不同。
Diffusion coefficients of phosphate and chloride ions in four different textural soils at varying water content and temperature were measured by the method of diffusion- cell using^(32)p and^(36)Cl labeled KH_2PO_4 and CaCl_2 solutions,respectively.The results showed that as the soil water content(W)increased the diffusion coefficients of phosphate (D_a)increased,the relationship between D_a and W could be described by the power equa- tion of D_a=aW^b.However,a near linear increase the diffusion coefficient of chloride(D) with increasing soil moisture.Under 20% water content,the diffusion activation energies for chloride ions in the four soils decreased in the order as loessal soil>black lu soil>lou soil>yellow cinnamon soil,but the reverse order for phosphate in the soils,which indicat- ed that the mechanisms for the diffusions of chloride and phosphate were different because of interactions between soil and phosphate or chloride ions.
出处
《中国农业大学学报》
CAS
CSCD
北大核心
1997年第S1期65-69,共5页
Journal of China Agricultural University
关键词
磷
氯
扩散系数
扩散机理
phosphate
chloride
diffusion coefficient
diffusion mechanism
