This chapter explores the physical, chemical, and microbiological factors influencing the solubilization of magnesium (Mg) silicates. In addition, studies of the effectiveness of Mg silicate-containing rocks, such as dunite and thermomagnesium (TM), as alternative fertilizers in tropical soils are discussed. Greenhouse and field experiments have demonstrated that these materials enhance Mg and silicon availability, improve photosynthetic efficiency, and increase crop yields in soybean and corn systems. Dunite application raises soil pH and provides steady release of Mg, while TM, especially in finer particle sizes, has superior nutrient release and agronomic performance. These findings highlight the potential of Mg-silicate agrominerals as eco-friendly fertilizers that can reduce reliance on conventional inputs and support sustainable agriculture in nutrient-depleted tropical soils.