Diógenes, L.C. et al. 2017. Microbial activities, carbon, and nitrogen in an irrigated Quartzarenic Neosol cultivated with cowpea in southwest Piauí. Semina: Ciências Agrárias. 38, 4 (Aug. 2017), 1765–1774. DOI:https://doi.org/10.5433/1679-0359.2017v38n4p1765.