Granulation of Phosphate Organomineral Fertilizer as a Strategy for Soybean Fertilization
Calcined bone meal, Poultry litter, P recycling, Nutrient export, Sustainability, Glycine max.
The low efficiency of phosphate fertilization in acidic tropical soils and the reliance on imported phosphate fertilizers underscore the need to develop sustainable alternative sources. In this context, the objective was to develop an organo-mineral phosphate fertilizer based on poultry litter and calcined bone meal, evaluate its chemical characteristics, and compare it with a mineral source regarding nutritional status, agronomic characteristics, yield, soil chemical attributes, and nutrient export by soybean grains. The experiment was conducted at the State University of Mato Grosso (Alta Floresta Campus) on a Dystrophic Red-Yellow Latosol. A randomized block design was used in a 2x4 factorial arrangement with three replications. Treatments consisted of two phosphorus sources, one mineral (monoammonium phosphate - MAP) and one organo-mineral (calcined bone + poultry litter + MAP + ash + additive), and four total P2O5 rates (0, 30, 60, and 120 kg ha⁻¹). Nutritional status, agronomic characteristics, grain yield, soil chemical attributes, and nutrient export by soybean grains were evaluated. The mineral and organo-mineral P sources yielded similar results for all variables, except for iron content in plant tissue, which was higher with the organo-mineral source. P2O5 rates had a greater influence on the evaluated parameters, resulting in higher foliar P content, increased vegetative growth, and improvements in yield components, productivity, and the export of macronutrients and micronutrients. However, neither the sources nor the rates influenced soil attributes by the end of the experiment. It is concluded that the organo-mineral fertilizer produced from poultry litter and calcined bone meal exhibited chemical characteristics suitable for agricultural use and agronomic performance comparable to conventional mineral fertilizer in soybean cultivation. Furthermore, it demonstrated potential for the recovery of phosphorus and other nutrients present in agricultural waste, representing a sustainable alternative for the efficient use of phosphate fertilizers.