Potassium dynamics in representative soils of low, mid and high altitude zones of North Kashmir

Three altitude- low (Silty clay loam), mid (Clay loam) and high (Silty loam) zone soils of District Ganderbal, Kashmir (India) were studied for quantity/intensity (Q/I) relationship to evaluate the K dynamics. K_L, ΔK°, K_X and PBC^K were found to be higher in mid altitude soils. The values of K_L, ΔK°, L_X, and K_X ranged from 0.50 to 0.60, 0.12 to 0.15 and 0.38 to 0.44 cmol Kg⁻¹ in mid, low and high altitude soils respectively. The equilibrium activity ratio (AR_e^K) of K varied from 0.34 to 0.82 × 10⁻³(mole/l)^0.5, potassium buffering capacity (PBC^K) from and free energy (−ΔG) of K – (Ca+Mg) exchange ranged between 22.7 to 34.7 (cmol Kg⁻¹)/(mole/l)^0.5 and - 4.2 to - 4.7 K cal mole⁻¹ respectively. The soils showed high capacities to maintain the potential of K against depletion, as they represented very high linear PBC^K. Significant correlations were found between Q/I parameters and soil properties. Among the studied soil attributes, most of the variation was accounted for i) by organic carbon, clay, cation exchange capacity (CEC) and exchangeable K (Ex-K) on K_L, “K° and K_X; ii) by pH, electrical conductivity (EC) and CaCO₃on AR_e^K and Δ G.