Comparative Analysis of Extractants and Temperature on Desorption of Non-Exchangeable Potassium under Different Land Uses of the North Western Himalayas

Abstract

For better comprehension of ecosystem sustainability, assessment of every contributory factor is of paramount significance. The non-exchangeable potassium desorption was examined in the respective samples of all the soils at three separate incubation  temp’s of viz. 20^oC, 30^oC and 40^oC,  making use of distinct two organic acids viz. 0.01 M oxalic acid and 0.01 M citric acid under different land uses of temperate lesser Himalayas. Higher amounts of non-exchangeable K were noted to be released through oxalic acid as an extractant ensued by citric acid. The amount of non- exchangeable K desorbed at three different temperatures differed significantly with maximum desorption at 40^oC followed by 30^oC and least at 20^oC. In describing the desorption: kinetics, even though the type of kinetic model remained mostly unaffected, however, the values of b were observed to increase in K-treated soils i.e. from 0.308 cmol K kg^-1 to K-saturation (100 cmol K kg^-1) and with increase in temperature from 20^oC to 40^oC, indicating a pronounced release of non-exchangeable potassium in K-treated soils at higher temperatures.