Are Chemical Properties of the Soil Influenced by Cover Crops in the Cerrado/Caatinga Ecotone?

Abstract

ABSTRACT In Brazil, light-textured soils cover approximately 8% of the national territory. The present study assesses the effect of using cover crops, in monoculture or intercropping, and soil management systems, in different layers, on soil chemical properties in the Cerrado/Caatinga ecotone, Brazil. The study was carried out in the southwest region of Piauí State, Brazil, in an area of Andropogon grass (Andropogon gayanus Kunth) in an advanced stage of degradation. The experiment comprised cover plants in monoculture or intercropping. Cover crops improve the following soil chemical properties: pH (+15.94%), calcium (+93.54%), magnesium (+34.17%), sum of bases (+88.30%), base saturation (+198.52%), potassium (+7,767.90%), phosphorus (+673.86%), extractable aluminum (−52.67%), potential acidity (−9.15%), and aluminum saturation (−66.16%). However, soil organic matter content and cation exchange capacity decrease by 42.54% and 35.27%, respectively, in comparison to the values before the experiment. Intercroppings Urochloa brizantha + Oryza sativa and Crotalaria paulina + Zea mays have the potential to improve soil chemical properties in the medium and long term.