LAUSR

The experiment was conducted under controlled conditions in the municipality of Sobral, Ceará, Brazil, to evaluate the agronomic efficiency of phosphate fertilizers with different solubilities on the cultivation of sorghum in a Luvisol. The experimental design comprised randomized blocks in a 2 × 6 factorial scheme (two genotypes and five phosphorus treatments plus the control, without phosphorus). The treatments were: monoammonium phosphate, triple superphosphate, sheep manure, organic compost based on livestock residues, and organomineral fertilizer. Three blocks were used, and each plot comprised composed of a pot containing two plants. Sixty-five days after germination, the plants were harvested for evaluation of biometric data, biomass, accumulation of nutrients in the aerial part, soil fertility, agronomic efficiency index of the phosphate fertilizers and triple superphosphate equivalent. The organomineral and triple superphosphate fertilizers had the highest agronomic efficiency for production of sorghum biomass. The more soluble sources (organomineral, triple superphosphate and monoammonium phosphate) enabled a better phosphorus recovery rate and physiological efficiency than the sources with low solubility.