Use of Maize Straw or Animal Manure as an Alternative to Gypsum to Ameliorate Saline-Sodic Soils

This work aimed to evaluate the effect of the addition of animal manure or maize straw, combined or not with gypsum, on the recovery of the productive capacity of a Fluvic Entisol affected by salts cultivated with maize (Zea mays L.). The experiment was conducted in a greenhouse, in PVC columns in a 10 x 4 factorial scheme, with ten treatments and four replicates (gypsum, 15 t ha-1 manure, 30 t ha-1 manure, 15 t ha-1 maize straw, 30 t ha-1 maize straw, 15 t ha-1 gypsum plus manure, 30 t ha-1 gypsum plus manure, 15 t ha-1 gypsum plus maize straw, 30 t ha-1 gypsum plus maize straw and control, no input) in a randomized block design. Soils that received maize straw increased both the soil water infiltration rate and the amount of salts leached at the bottom of the column compared to soils that received gypsum. However, maize straw reduced the growth of maize plants, probably due to the immobilization of nutrients. In soils that received 15 t ha-1 manure, the growth of maize plants was higher compared to soils that received gypsum, indicating that the application and organic inputs can improve soil physical conditions, reduce salinity and promote plant growth without the need for the acquisition of gypsum, which gives farmers more autonomy and reduces costs.