Vol. 11, Issue 11 (2022)

Potassium fixation of soils is an important phenomenon affecting the status of soil K and its availability to crops. It is the process in which soils converting exchangeable or water soluble potassium to fixed form in the inter lattice position of clay minerals. Potassium releasing power refers to the inherent capacity of the soil to supply K to growing plant from its natural source. The present study was undertaken to know the potassium fixation and release characteristics in the profile soil samples of southern transect of Bengaluru. The results prevailed that the average highest rate of potassium fixation was observed in the profile-8(0.41 cmol (p+) kg^-1) and lowest in the profile-2 (0.17 cmol (p+) kg^-1). The total step potassium release from surface soils of mulberry, agriculture, vegetable and plantation land use profiles ranged from 143 to 578, 99 to 175, 83 to 106 and 63 to 139 mg K kg^-1, respectively. Constant rate K varied within the narrow limit of 3 to 20 mg kg^-1 in spite of wide variations in step K contents of the soils.