Potassium dynamics in inceptisols as influenced by graded levels of potash for banana: III. Q/I relations and K kinetics

ABSTRACT

Quantity–intensity (Q/I) relationships of potassium (K) serve as a better index of K supplying power of soil. A laboratory study was carried out to study the effect of the levels of potash application to banana on Q/I relations and kinetics of potassium in soil. The activity ratio of potassium (AR^k₀), labile potassium (K_L), potassium held at nonspecific site (ΔK₀), and potassium held at specific sites (K_X) tended to increase with increasing K fertilization. As per the threshold values of free energy exchange (ΔG), the soil appeared to possess optimum amount of available K (−2500 to −3000 cal mol⁻¹). Among the four equations used to describe the non-exchangeable K release in soils, the zero-order and Elovich models showed excellent linear and distinct differences with increasing time; however, the power function and parabolic models do not differentiate K release pattern at different time intervals.

KEYWORDS:

• Banana
• K kinetics
• Q/I relations

Acknowledgments

The authors are also grateful to the Soil Test Crop Response Correlation Project (ICAR), MPAU, Rahuri (M.S.) for providing necessary facilities for conducting the experiment.

Additional information

Funding

The authors are grateful to the International Potash Institute, Switzerland, for the financial support provided for this research.