AZEVEDO, N. C.; AZEVEDO, Norma César de.
Abstract:
The objective of this work was to verify the effects of several chemical correctives (gypsum, sulfuric acid, gypsum + sulfuric acid, calcium carbonate + sulfuric acid) and saline water with successive dilutions in the physical and chemical properties of a saline-sodium soil of the Irrigated Perimeter of São Gonçalo (Sector 10). The effects of gypsum and sulfuric acid on the development and production of irrigated rice (Oryza sativa, L.) were also studied. In the first stage of the work, developed in Laboratory, the effect of different treatments on the physical and chemical properties of the soil under study was evaluated using PVC (0 1Ocm) columns filled with soil up to 20cm. The amount of corrective applied was based on the interchangeable sodium equivalent present in the soil column, and in the mixed treatments, only 25% of the equivalents were applied in the form of calcium salts. It was verified that the treatments gypsum + sulfuric acid and sulfuric acid promoted a higher speed of infiltration and accumulated infiltration compared to gypsum and calcium carbonate + sulfuric acid. The treatments with saline water showed greater influence in the increase of the hydraulic conductivity whereas among the chemical correctives the sulfuric acid was outstanding, presenting final values in rice mediated reduced the percentage of interchangeable sodium from 86.5% to 42.7% in the depth of 0 - 10 cm, thus showing the possibility of using saline-sodium soils in rice production.
