Response of Chickpea to Potassium Fertilization in Vertisols under Rainfed Agro-ecosystems

Abstract

A field experiment was conducted during the rabi season of 2024–25 at the Regional Agricultural Research Station, Nandyal, to study the effect of different potassium levels and sources on the growth, yield, nutrient uptake and soil fertility in chickpea grown on Vertisols under rainfed conditions. The experiment included eight treatments involving combinations of recommended dose of fertilizers (RDF), soil-applied potassium at varying levels (20, 30, and 40 kg K/ha), foliar application of potassium nitrate (KNO₃ at 1%), and potassium solubilizing bacteria (KSB). The results indicated that the combined application of 30 kg K/ha with 1% KNO₃ foliar spray (T7) recorded the highest seed yield (2133 kg ha-1), 100-seed weight (29.7 g), and plant potassium content (1.51% at 45 DAS and 1.29% at harvest). This treatment also maintained higher residual soil potassium levels. Although individual potassium treatments improved plant and soil K content over the control, the integrated soil and foliar application significantly enhanced potassium uptake and yield performance. The study highlights the importance of potassium nutrition, often overlooked in pulse production, for sustainable chickpea cultivation under rainfed conditions.