Acidification of soils with the use of S and cattle manure in northern Minas Gerais

Unlike the techniques for raising soil pH, there are few agronomic alternatives for reducing the pH of alkalised soils in order to make them productive. Irrigation with water rich in calcium carbonates alkalises soils in the Brazilian semi-arid region, as the pH rises above the ideal range for cultivation (5.7 to 6.5) and this drastically reduces the availability of nutrients such as P, Fe, Mn, Zn, S, B and Cu. The aim of this study was to assess the efficiency of doses of elemental sulphur (S°) and cattle manure in correcting the pH of alkalinised soils in the north of Minas Gerais. The doses tested were 0; 0.5; 1.0; 2.0 and 4.0 t/ha of S° combined with 0, 10, 15, 25 and 50 t/ha of cattle manure using the Double Square experimental matrix, and the characteristics assessed were active acidity (pH in water), total acidity (H+Al), electrical conductivity, Ca2+, Mg2+ at different dates.