Uso do biocarvão como condicionador de solo sódico em cultivo biossalino de algodão.

Abstract

The recovery of soils degraded by salinization is one of the great challenges for agricultural development in the semiarid region of the Northeast, especially in irrigated perimeters. In this sense, researchers are looking to use alternative products, such as biochar as one of the viable alternatives, due to the improvements in the chemical, physical and biological properties of the soil that have already been proven. Thus, the objective of this research was to evaluate the use of biochar produced from green coconut biomass, in the recovery of a sodic soil from the irrigated perimeter of São GonçaloPB, in addition to the growth and development of the cotton BRS Aroeira. The experiment was carried out in a greenhouse with a factorial scheme (4 x 4) + 1, with four doses of biochar (5, 10, 15 and 20 t.ha1), four periods of incubation of biochar in the soil (0, 15, 30 and 45 days) and an additional treatment (10 t.ha1 of lime+20m³.ha1 of organic compost), in a completely randomized design, with three replications, totaling 51 experimental units. After the processes of incubation of biochar in the soil and application of the leaching layer, there were reductions in pH (18.64%), in electrical conductivity in the exchange complex CEct (73.82%), in addition to Na+ ct contents (89.4%) and K+ es, in relation to the initial values of the soil. Through the contrast, it was noticed that the saturated hydraulic conductivity of the soil (K0) obtained by the treatments with biochar was 957.14% higher than the average of the additional treatment. As for the biometric variables of cotton, there was a positive influence of the doses of biochar applied in all periods evaluated at the end of the growth phase for: stem diameter, plant height, number of leaves and leaf area, at a dose of 20 t.ha1. The treatments with the use of biochar provided an average production of cottonseed 10.19% higher than the additional treatment. In general, the use of biochar in the treatment of soil with sodicity problem proved to be efficient, with results equivalent to those of the use with calcium carbonate (additional treatment) in several studied variables.