Land-use change effect on the hydro-dynamic characteristics of soil in the Brazilian semi-arid region

Abstract

The search for better living conditions has led the residents of the Brazilian semi-arid region to plant forage crops, leading to a gradual decrease in the native vegetation (Caatinga) of this region. The effects caused by the replacement of Caatinga with palm, for example, have been little studied, especially with regard to the physical and hydraulic properties of the soil. The objective of this study was to compare the physical-hydraulic characteristics of a litholic neosol in two areas having different vegetation cover: one area cultivated with forage palm (O. ficus-indica) and the other covered by native Caatinga. Differences in soil structure, especially in porosity, between the natural and cultivated soils were observed to control the hydrodynamic processes, resulting in changes in water retention curves and hydraulic conductivity. Natural soil presents low values of hydraulic conductivity when compared to those of cultivated soil. This increase is probably due to soil management required for forage palm cultivation. The natural soil structure, characterized by relatively low saturated hydraulic conductivity values, presents an infiltrability that favors surface runoff. Human activities in the study area have promoted changes in the soil’s physical attributes, decreasing density and increasing porosity. Consequently, there is an increase in water infiltration into the soil and a reduction of runoff in cultivated areas, confirming results obtained in previous studies.

Água No Solo Em Função Do Volume De Chuva Em Diferentes Texturas Do Solo Em Ambiente De Pastejo No Cerrado

“…A ocorrência de chuva de forte intensidade (precipitação > velocidade de infiltração de água no solo), propiciou infiltração de água no solo até a profundidade de 8,3 cm em condição de solo argiloso e 6,3 cm em solo arenoso, porém, sem efeito significativo (p>0,05) no solo com textura arenosa (Figura 2). Os solos argilosos tem sua infiltração governada por forças capilares e gravitacionais, lhe proporcionando uma adsorção superior a solos arenosos que apesar de sua quantidade superior de macroporos tem-se pouca influencia da capilaridade (SOARES et al, 2020). Houve ganho médio de umidade do solo a base de massa em função do volume de chuva de 10,5%, 9,5% e 6,3% nas camadas de 0-10, 10-20 e 20-40 cm, respectivamente.…”