An assessment of the agronomic benefits of silicate rock powders in Brazil in the context of a novel classification

Philipp Swoboda, Eder de Souza Martins, Gisele Freitas Vilela, Luis Ferreira, Carlos Augusto Posser Silveira, Giuliano Marchi, Mariane Chiapini, Marcella Daubermann, Mayra Maniero Rodrigues, Matthew Oliver Clarkson, Junyao Kang, Veronica Furey, David Manning, Christina Larkin

The sustainable intensification of tropical agriculture requires innovative approaches to restore soil health, reduce dependency on imported fertilizers, and increase crop productivity. Brazil has emerged as a global leader in the use of silicate agrominerals (ASi), silicate rich rock powders that supply plant nutrients and improve soil properties. These materials could advance low-cost soil sustaining crop production, particularly in the deeply weathered and nutrient-depleted soils of the tropics. However, the research landscape remains fragmented, and there is currently no synthesis of tropical ASi experiments. This article integrates findings from 54 Brazilian crop trials using a novel classification system for ASi based on lithochemistry and practical agricultural considerations. It evaluates the effects of ASi on soil health parameters, plant growth, and nutrient uptake across a range of crops and tropical soil types. The results demonstrate that ASi can significantly improve soil pH, cation exchange capacity, and base saturation, while enhancing yield and nutrient availability. Furthermore, a consistent trend emerged indicating that ASi can indirectly increase soil phosphorus availability. We recommend minimum requirements for standardized methodologies and suggest real-world research designs to support broader ASi adoption. Brazil's pioneering role offers valuable insights for scaling the usage of silicate agrominerals across tropical agricultural systems worldwide, contributing to sustainable food production and climate resilience.