Factors influencing the release of plant nutrient elements from silicate rock powders: a geochemical overview

A.D. Harley & R.J. Gilkes Abstract Rock-forming minerals of igneous and metamorphic rocks contain most of the nutrients required by higher plants for growth and development. Ground rock fertilisers may provide a source of nutrients to depleted topsoils where bulk soil solutions are not in equilibrium with fresh primary minerals. Slow dissolution rates of silicate minerals may inhibit the use of rock powders in agriculture unless suitable soils are identified and optimum rock powder properties developed. This review identifies previous research where the agronomic effectiveness of ground rock fertilisers has been evaluated. There are many ...