Vol. 11, Issue 12 (2022)

Author(s):
Ramesh, Vijay Kumar C, KK Math and Shubha S

Abstract:
In Alnavara Taluk of Dharwad District, the distribution of various potassium (K) forms were examined in four land use systems, including paddy, maize, sugarcane, and forest-based land use systems. The soils were acidic to neutral in reaction (5.35 to 6.10) in surface layer and slightly low pH was noticed in the soils of forest ecosystem. The EC is normal in range and the cation exchange capacity of the soils were low to medium (13.54 to 28.28 cmol (p+) kg^-1) and increased with depth in all the land use systems. The soils of the taluk were low to medium in organic carbon and medium to high in potassium contents. Higher SOC (1.88 to 10.52 g kg^-1) was recorded in the soils of forest ecosystem followed by sugarcane, maize and paddy based land use system. Among different land use systems sugarcane-based land use system recorded higher potassium fractions content i.e. WS-K (3.58 to 5.10 mg kg^-1), exchangeable-K (102.73 to 170.68 mg kg^-1), lattice-K (10222 to 11198 mg kg^-1) and total-K (10750 to 11750 mg kg^-1). All fractions of K were significantly and positively correlated with CEC except water soluble K. The water soluble-K was significantly and positively correlated with OC in all the land use systems. Vertical distribution of different forms of K revealed under different soil profiles, the water soluble, exchangeable, available and non exchangeable forms of potassium decreased with depth. Whereas, non-exchangeable K, total-K and lattice-K did increased with depth.