Potassium Fixation and Release Characteristics in Acidic Soils of Three Different Soil Orders of West Bengal, India Roy Atrayee, Banik Ganesh Chandra*, Mandal Subhadeep Department of Soil Science and Agricultural Chemistry, Faculty of Agriculture, Uttar Banga Krishi Viswavidyalaya, Pundibari, 736165, Cooch Behar, West Bengal, India *Corresponding author (Email: gcbanik79@yahoo.co.in)
Online Published on 16 January, 2024. Abstract Determination of potassium (K) fixation and the release pattern from the soil is important to measure K availability for plant uptake. This study aimed to assess the rate of K fixation and release kinetics in ten acidic soils of three contrasting soil orders (Inceptisol, Entisol and Alfisol) available in West Bengal in different agro-climatic zones where data is scanty. Inceptisols of hilly regions had low K contents, while Alfisols and Entisols had variable K contents. The K fixation patterns varied in different soils, and the K fixation percentages were higher in K-deficient soils. However, K fixation percentage decreased progressively with an increase in the rate of K application. With 50 mg kg-1 of K application, the percentage of K fixation was minimum in Ruisanda soil (43.8%) and the maximum was in Chunabhati soil (68.5%) under soil order of Alfisol and Entisol, respectively. On the contrary, K release was more from soils with higher non-exchangeable K content. Examination of cumulative K release indicated the diffusion-controlled K release process in soils. The cumulative K release by each extraction varied from 36.16 mg kg-1 in Kalimpong soil (Inceptisol) to 75.64 mg kg-1 in Ruisanda soil (Alfisol) in the first 15 minutes. It increased with time up to 180 minute. The fitting of release data in various mathematical models was also tested to find out the dynamics of K release. Parabolic diffusion, Elovich diffusion, Power function, and First order equations were used to determine the K release patterns of soils. The K release rate was highest in high native K containing Ruisanda soil and lowest in low K containing Kalimpong soil, indicating the more frequent K fertilization requirement in Kalimpong soil. Top Keywords Potassium, Fixation, Release isotherm, Kinetics, Acid soil, Soil order. Top |