Potassium forms and characteristics of hilly soils of Chumekedima district, Nagaland

Soil properties assessments of an area provide critical baseline information on crop health and productivity.Therefore, a study for assessment potassium forms and soil characteristics of the hilly soils of Chumukedima district, Nagaland was undertaken during 2021-22.Forty eight surface soil samples (0-15 cm) from cultivated fields were collected from twelve villages and analyzed for various physicochemical properties, fertility status and potassium forms.Results revealed that the soils were very strongly to strongly acidic in reaction and normal in total soluble salts.The CEC, bulk density, particle density and porosity of the soils ranged from 10.00 to 13.60 cmolc kg -1 , 0.99 to 1.36 Mg m -3 , 2.26 to 2.67 Mg m -3 and 40.10 to 61.28%, respectively.Nutrient index value for OC, N, P, K and S was found 3.00, 1.29, 1.33, 2.00 and 1.00 indicated that soils were high, low, low, medium and low, respectively in these nutrients.The exchangeable calcium and magnesium of the soils varied from 1.24 to 2.10 cmolc kg -1 and 0.48 to 0.96 cmolc kg -1 , respectively.The watersoluble K, exchangeable K, non-exchangeable K and HNO3 extractable K in the soils ranged from 9.8 to 15.4 mg kg -1 , 53.1 to 86.7 mg kg -1 , 474 to 598 mg kg -1 and 538 to 700 mg kg -1 , respectively.Available nutrients had significant positive correlation with OC.Potassium fractions and CEC had significant positive correlation with organic carbon.Highly significant positive relationship amongst different forms of K indicated existence of dynamics equilibrium among various forms of K. Hence, regular monitoring of soil characteristics and balanced nutrient addition through manures and fertilizers is essential for sustainable crop production.