ABSTRACT Natural phosphate rocks (PR) are characterized by low phosphorus (P) solubility in water. Acidulation is the normal method to raise P solubility of these materials, however, it increases the cost and causes operational issues. The aim of this study was to evaluate the agronomic efficiency of partially acidulated and micro-granulated Arraias phosphate rock, which has a lower P content (6.88 %) than normal apatite concentrates. Two experiments were carried out in a greenhouse at the University of Rio Verde, […]