ABSTRACT: In alkalinized and Ca-rich composts, solubilization of apatite from phosphate rocks (PRs) is not guaranteed; however, chelating agents and humified substances produced during composting may alter the soluble contents and P forms of monoammonium phosphate (MAP)-based composts. These effects may depend on the proportions of organic wastes and P source used in the compost piles. The aim of this study was to evaluate the effect of composting chicken manure, coffee husk, and Araxá PR, Bayóvar PR, or MAP in different proportions on the organic matter decomposition, total N, Ca contents, and soluble P fractions in the composts. The treatments consisted of a 3 × 4 × 2 factorial, through the combination of three P sources [Araxá PR, Bayóvar PR, and MAP],... |