Feasibility evaluation of the use of mud residue from marble shop as soil remineralizer

Brazil is a major producer of dimension/ornamental stones, with a great diversity of raw materials. The sawing process transforms 20 to 30% of the extracted block into powder, with the generation of fine waste around 800,000 t/year. An alternative to reusing this waste is its application as a source of nutrients for the soil. This study evaluated the potential use of mud residue from a marble shop located in João Monlevade, Minas Gerais, as a remineralizer, based on fertility, mineralogical and chemical analysis performed by X-ray diffraction and X-ray fluorescence. For fertility, pH in CaCl2 0.01 mol L-1, organic matter, aluminum saturation, potential acidity, sum of bases, cation-exchange capacity, base saturation, macro and micronutrients were determined. The studied residue has free silica, the sum of basis, and K2O content in the range established by MAPA to be certified as a remineralizer. The sample contains 6.7% phyllosilicates, a source of faster K availability, and 19.4% K-feldspar, a slow-release source. Results described in this study indicate that residue can be a promising, efficient, and low-cost alternative to improve soil fertility.