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

Emily Dionizio,Marcos Costa

doi:10.3390/agriculture9010024

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.

Highlights

In the last decade, the rapid expansion of agribusiness in the Cerrado led to a new Brazilian agricultural frontier known as MATOPIBA, which have raised concerns about the natural resources conservation [1,2], especially regarding to the water availability [3,4,5].In MATOPIBA, Western Bahia stands out by the agricultural expansion, representing 49% of the total agricultural area [6] with 1.8 million hectares in 2015, which is equivalent to an increase of 352%since 1985 [7,8]
Western Bahia is located above the Urucuia Aquifer and is drained by the Grande, Corrente and Carinhanha basins, there is a major concern about the regional water availability and the impacts of the agricultural activities on Cerrado biome [1,2,5]
The average sand content ranged between 69.47% and 85.79% within the predominant soil classes, while the average clay content ranged between 11.29% and 26.87%

Summary

Introduction

The rapid expansion of agribusiness in the Cerrado led to a new Brazilian agricultural frontier known as MATOPIBA (acronym for the states Maranhão, Tocantins, Piauí andBahia), which have raised concerns about the natural resources conservation [1,2], especially regarding to the water availability [3,4,5].In MATOPIBA, Western Bahia stands out by the agricultural expansion, representing 49% of the total agricultural area [6] with 1.8 million hectares in 2015, which is equivalent to an increase of 352%since 1985 [7,8]. The region stands out for its high productivity records, reaching to 7.4 million tons of soybean, cotton and maize crops in the 2016/2017 harvest [10], confirming the potential of the agribusiness and the systematic dependence of the water availability and natural resources. Western Bahia is located above the Urucuia Aquifer and is drained by the Grande, Corrente and Carinhanha basins, there is a major concern about the regional water availability and the impacts of the agricultural activities on Cerrado biome [1,2,5].

Objectives

Methods

Results

Discussion

Conclusion