Avaliação de técnicas de conservação de água e solo em bacia experimental do Semi-Árido pernambucano

Abstract

The soil is one of the natural resources more intensely used for food production, being subject to have its productive capacity reduced by the erosion, as a result of its inadequate use and management. The erosion not only carries particles from the soil, but also carries organic matter, important factor to nutrients availability to the plants. Hence this work aimed to evaluate the influence of conservation practices for the soil and water losses by the hydric erosion, in a Fluvic Neossol in the semiarid zone of Pernambuco State, with the purpose of producing simple and low cost recommendations, for the local farmers, appropriate and efficient in reducing the hydric erosion. Simulated rain with intensities between 54 and 60 mm/h have been applied on the following treatments: bean cultivated in level (N1) with rock barriers between each row of plantation, in the spacing of 0.5 m; bean cultivated in level (N2) with rock barriers in the spacing of 1.0 m; bean planted downslope (DS); bean planted in level with mulching cover (MC), using bean straws; cleared bare soil (CB) and natural covering (CN). The erosive values had been calculated from the collections of the runoff material. Amongst the evaluated treatments, the mulched cover, on average, exhibit reduction of 86,91% in the soil losses, with values close to the one to the ideal condition of covering, which is the natural condition. The results of the total organiccarbon lost in the sediments of the treatment without conservation practice had prresented significant amounts of carbon being carried out to the lower parts of the plot. Conditions MC and CN had presented reduction of 94.73 and 98.70% in relation to the cleared bare soil plot. Amongst the conservation practice studied, the mulching cover presented the highest reduction in the soil erosion.