Vol. 8, Issue 3, Part G (2024)

Abstract: The concepts of quantity-intensity and buffering capacity help describe and measure the potassium-supplying power of soils. The intensity factor (I) measures K in soil solution, i.e., immediately available for plant absorption, varies with the amount of labile form of this element (quantity). Quantitatively, the buffering capacity is expressed as the ratio ∆Q/∆I. The wider the ratio of ∆Q/∆I, the more buffered the soil. So, quantity-intensity characteristics of potassium were studied to quantify the potassium availability in coastal alluvial soils under the paddy cover of the Udupi district. The investigation results indicated that the specifically bound potassium (K_X), a part of labile K, and the K retained by nonspecific sites (-∆K^o) were deficient. Hence, these soil’s labile potassium (K_L) appeared to be low. The low values of PBC^K (14.39, 07.00, 09.00 cmol (p+) kg^-1) indicated that the soils had meager potassium buffering capacity (PBC^K), probably due to their low clay content.