Impact of low potassium fertilization on potassium transformation under different crop management systems in western plain of arid India

Acquaintance of potassium (K) transformation in soil is crucial for K management in management system of arid India. Present study revealed that the extractable K like ammonium acetate–potassium (NH₄OAc–K), nitric acid (HNO₃)–K, and hydrochloric acid (HCl)–K under different systems were followed the order: irrigated low input > rainfed low input > irrigated high input > no input. The pearl millet systems in irrigated low input practice maintained a higher NH₄OAc–K than irrigated high input practice. The exchangeable-K (Exch-K), non-exchangeable-K (Non-exch K) and lattice-K were observed highest in irrigated low input system and lowest in no input system. It is noticed that Exch-K contributed 2.3–2.6% over total-K, which readily available to plants. The Exch-K was highly significant correlated with K pools and soil properties, indicating that rapid establishment of equilibrium between the pools. Thus, knowing K reserve and distribution of K forms can help in understanding K replenishment capacity of arid soil under long-term intensive cultivation.