Solos salino-sódicos condicionados com gesso e enxofre com Acidithiobacillus thiooxidans

Abstract

Saline-sodic soils occur, especially, in arid and semi-arid regions due to the source material, low precipitation and high evapotranspiration. Inadequate management is one of the causes and the main damage is the degradation and abandonment of these areas. These soils must be corrected in order to reduce the pH, the concentration of soluble salts and exchangeable sodium to improve the quality of the soil. The main objective of the work is to compare the elemental sulfur inoculated with the oxidizing bacteria genus (Acidithiobacillus) which produces sulfuric acid and can be used in the conditioning of saline-sodic and sodic soils and its effect compared with gypsum and the mixture of the two materials. The main objective of the work is to compare the elemental sulfur inoculated with the oxidizing bacteria genus (Acidithiobacillus) which produces sulfuric acid and can be used in the conditioning of saline-sodic and sodic soils and its effect compared with gypsum and the mixture of the two materials. The experiment was carried out in a greenhouse in a 2x4 factorial scheme, using two saline-sodic soils; four treatments: 1) gypsum (11.5t ha-1 for S1; 17.5 t ha-1 for soil 2,); 2) elemental sulfur with Acidithiobacillus thiooxidans, 3) sulfur with Acidithiobacillus thiooxidans 50% (1t ha-1 for S1; 1.63t ha-1 for S2) + 50% gypsum (7.75t ha-1 for S1; 8, 75t ha-1 for S2) and 4) control (soil without conditioner), Four incubation times (0;15;30 and 45 days) with three replications were used. after performing the application of a leaching blade, being the first in the setup of the experiment (0 days), and then in the other incubation time. samples were collected for chemical analysis of soils and leachate material. Elemental sulfur with Acidithiobacillus thiooxidans promoted greater pH reduction; electrical conductivity and exchangeable sodium percentage in the soil, being more efficient in reducing salinity and sodicity, when compared with gypsum and 50% sulfur with Acidithiobacillus thiooxidans + 50% gypsum. Gypsum provided an increase in the concentration of Ca2+ for both soils. At 45 days of incubation, it had a positive effect with the conditions on chemical improvement and reduction of soil sodicity. But it is necessary to increase the incubation period for greater efficiency in soil recovery.