Influence of Land Use and Land Cover on Hydraulic and Physical Soil Properties at the Cerrado Agricultural Frontier

Abstract

Western Bahia is one of the most active agricultural frontiers in the world, which raises concern about its natural resources conservation, especially regarding water availability. This study evaluated the influence of five different land uses and land covers on physical and hydraulic soil properties, and developed pedotransfer functions to derive regional hydraulic properties. Significant changes between physical and hydraulic soil properties under agricultural areas and under natural vegetation cover were found, reinforcing that agricultural activity may influence the soil water balance. Cerrado and Forest formation areas have higher infiltration rates ( K s a t ) compared to managed areas, with average values of 16.29 cm h−1, and 14.47 cm h−1, while irrigated croplands, rainfed croplands and pasture areas have much smaller infiltration rates, with K s a t equal to 3.01 cm h−1, 6.22 cm h−1 and 5.01 cm h−1, respectively. Our results suggest that the agriculture practices do not directly affect the vertical nature of hydrological flowpath, except in the case of intensive irrigated agriculture areas, where K s a t reduction can lead to erosive processes favoring organic matter losses, and decreases in productivity and soil quality. Impacts of land use change on hydraulic and physical soil properties are a reality in the Cerrado agriculture frontier and there is an urgent need to monitor how these changes occur over time to develop effective mitigation strategies of soil and water conservation.