This book described the quantity/intensity relationships of potassium (K) in Vertisol under different organic and inorganic nutrient management practices. Potassium is an important plant nutrient affect the crop yield and soil health. Under different plant nutrient management practices K availability in soil solution affected by soil properties, type of input and soil microbial population. In this book quantity/ intensity (Q/I) characteristics of potassium were studied to quantify the potassium availability in Indian Vertisol of maize-chickpea cropping systems. The ratio of the activity of cations such as K+ and Ca2+ is defined by the relation aK/(aCa)1/2 where a is the ion activity. The concepts of quantity (Q) and intensity (I) have been applied to nutrient status of Indian Vertisol soils. During the study different parameters of Quantity/Intensity relationships was computed by Beckett (1964). This book is very much useful to researcher and academician working in the field of K management.