Organic carbon stock changes and crop yield in a tropical sandy soil under rainfed grains-cotton farming systems in Bahia, Brazil

ABSTRACT Most studies about soil organic carbon stock changes in the Cerrado (Brazilian Savanna) biome are either related to field data collected clayey Ferralsols or different land uses, as if they were equilibrium. This study aimed evaluate effect of tillage systems and crop sequences on yield, a sandy Ferralsol from Bahia, Brazil. The experimental design was randomized blocks, with four replicates. Soil samples after fve years cotton, soybean maize monocropping under heavy disk harrow leveling (conventional tillage), rotation green manure cover (no-tillage). Additional non-cultivated site (Neotropical Savanna, sensu stricto). conservation practices such no-tillage favored at 0-40 cm layer, highest values reaching 36.03 Mg ha−1. accrued conventional monoculture lower than no-tillage, which ranged 30.9 54.9 %, increasing annual rate 2.36 ha−1 during years. soybean-maize-cotton rotation, combination manure, increased cotton yields, simultaneous accumulation soil.