Potassium Quantity–Intensity Parameters and Their Correlation with Bean Plant Indices in Some Calcareous Soils

Abstract

Plant availability of potassium (K) in soils is controlled by dynamic interactions among its different pools. Potassium quantity–intensity (Q/I) parameters were determined to relate them to bean plant indices in a pot experiment. The results showed that the activity ratio at equilibrium (ARk) ranged from 0.015 to 0.358 (mmol L−1)0.50, the potential buffering capacity (PBC) ranged from 7.54 to 26.32 mmol kg−1/(mmol L−1)0.50, the labile K (Δk°) ranged from 9.1 to 112.2 mg kg−1, and the K adsorbed at specific sites (Kx) ranged from 6.51 to 69.69 mg kg−1. The results of pot experiment showed that some K Q/I parameters were significantly correlated with some plant indices. Also, the correlation study showed that readily exchangeable K was significantly correlated with K Q/I parameters except Kx. The results of this research show that the K Q/I method can be used for estimating of soil K availability for bean.