Waste mineral powder supplies plant available potassium: Evaluation of chemical and biological interventions

B.B. Basak, Binoy Sarkar, Peter Sanderson, Ravi Naidu Abstract A study was conducted to evaluate a waste rock powder collected from the Seaham quarry in New South Wales, Australia, as a source of potassium (K) in soil. The K supplying capacity of different size fractions of the mineral powder was evaluated by employing five chemical extractants as well as growing maize and holy basil in sand culture experiments. The K release by chemical extractants increased with decreasing particle size of the mineral powder. The amount of K released by different extractants followed the order: water < 0.01 M calcium chloride < 0.01 M citric acid < 1 N ...