Impact of management systems on chemical attributes of an Oxisol from MATOPIBA region, Brazil

Abstract: The MATOPIBA region, in the Cerrado, has been considered a promising new frontier of Brazilian agriculture. However, inadequate management of Cerrado soils has caused its fertility depletion, reducing crop productivity. This work aimed to evaluate the effect of soil management systems on chemical attributes of an Oxisol from MATOPIBA in the Cerrado. The studied areas, located inPiauiState, where: i) conventional tillage (three years) (CT); ii) no-tillage (16 years) + crop-livestock integration system (two years) (NT+CLI) and; iii) Cerrado native vegetation (NCV). Soil samples were collected (four replicates) from 0.00-0.10 and 0.10-0.20 m depths and soil chemical attributes were evaluated. Overall, the natural acidic and low fertility of the Oxisol as well as the available P, exchangeable K, Ca+Mg and Al contents, potential acidity and base saturation were improved in the agricultural areas compared to NCV, especially when NT+CLI was adopted. Decrease of soil organic matter content in NT+CLI compared to NCV was not observed, evidencing the potential of this system for maintaining carbon levels in the soil.  In our study, soil organic matter content in CT and NCV did not differ, probably due to the recent implementation of CT, which generally contributes to organic matter depletion. Monitoring effects of NT+CLI on attributes and quality of MATOPIBA Oxisols is crucial to elucidate the potential of this region to sustain intensive agriculture, the main purpose for opening this agricultural frontier. Keywords: Conventional tillage, No-tillage, Crop-livestock integration