PÓ DE ROCHA FOSFATADA E RESPOSTA EM ATRIBUTOS QUIMICOS EM SOLO ARENOSO E ARGILOSO

• DOI: https://doi.org/10.22533/at.ed.82751125300510

• Palavras-chave: Fosfato natural, fertilizante fosfatado, textura de solo.

• Keywords: Natural phosphate, phosphate fertilizer, soil texture.

• Abstract: Phosphorus (P) is an essential macronutrient, but it is poorly available in tropical soils due to fixation with Ca²⁺, Fe³⁺, and Al³⁺ ions, in addition to adsorption to soil colloids. Traditionally, highly soluble and expensive phosphate fertilizers are used. Research has evaluated less soluble and more economical natural phosphates. This study aimed to evaluate the effect of increasing doses of phosphate rock on soils with contrasting textures. The design was completely randomized, in a 2 x 5 factorial scheme, with the first factor consisting of two soils (sandy and clayey), and the second factor consisting of five incubated doses of natural phosphate in plastic bags: 0, 75, 150, 225, and 300 kg of P₂O₅ ha⁻¹, and an additional treatment with MAP. Chemical analyses showed that increasing doses increased the levels of P, Ca, Mg, and the sum of bases (SB), in addition to reducing potential acidity (H+Al) and raising pH. Phosphate positively influenced the increase in P levels in sandy and clayey soils, obtaining values of 38.53 and 12.16 mg dm-3, respectively. Sedimentary phosphate rock demonstrated potential as an alternative source of phosphorus and acidity corrector, with long-lasting residual effects and economic viability for tropical soils. It is concluded that the use of natural phosphates can partially replace soluble fertilizers, promoting sustainability and reducing external dependence.