Potassium fixation capabilities of some inceptisols belonging to plain and sub-mountainous region

The soils representing plains and sub-mountainous regions of extreme north-west India were studied for their potassium (K)-fixation characteristics. Significantly higher K-fixation capacity was observed in submountainous soils than the plains. Besides, significantly higher K-fixation capacity was observed in lower depths in comparison to upper depths in all the soils studied. Significant correlation obtained for K-fixation capacity with clay and CEC indicated that these properties would play a dominant role in the K dynamics. Two type of multivariate regression models were developed for prediction of K-fixing capacity. Models (Model A and B) were calibrated for their accuracy in predicting K-fixing capacity of soils. On comparing the observed and predicted values it was observed that the predictions based on model A were superior for plains, while the predictions based on model B were superior for sub-mountainous soils.