Effect of Different Factors on Diffusion Characteristics of Potassium in Alluvial Soils of Eastern Indo Gangetic Plain

摘要

To understand the transport behaviour of potassium as influenced by different factors, the tracer diffusion (D_a) and porous diffusion (D_p) coefficients of potassium were studied in three alluvial soils of varying potassium content and mineralogicalcomposition. Diffusion coefficients were increased with increase in moisture content (8), temperature (T), bulk density (d) and tracer:bckground ratio (R). The D_a and D_p values were significantly higher when NaCl was taken as background electrolyte than for CaCl_2. Soil with higher exchangeable K and illite content recorded higher D_a and D_p values. The energy of activation (E_a) decreased significantly with increase in bulk density and the Arrhenius frequency factor (A) and entropy factor of diffusion (o) were found to significantly decrease with increasing tracer component. Exchangeable K, nonexchangeable K and illitic fraction of the clay minerals was found most relevant factor predicting the diffusion coefficients of potassium in the alluvial soils.