The best result in soil pH (pH 6.9) was observed when sulfur was
applied at a rate of 3.2 t ha−1, in a mixing proportion (S*:G) equivalent
to 100:0. The effects on exchangeable Na+ revealed a great
reduction when higher levels of gypsum (G) and sulfur inoculated
with Acidithiobacillus bacteria (S*) were applied. When S*
and G were applied in the mixing proportions (S*: G) equivalent to
25:75 and 0:100, the best values of soil exchangeable Na+ (8.9 and
9.0 cmolc dm−3) were obtained. Some results of the exchangeable
Na+ after soil amendment were found to be below 15 (cmolc dm−3),
and Na+ in these concentrations do not promote injurious problems
in tolerant plants.
The soil electrical conductivity (Table 1) showed that salinity
below 4.0 (mS m−1) was obtained with G and S* applied at higher
rates, especially when the amendments were used in the same
percentage proportion (50:50)