Soil carbon and nitrogen dynamics linked to Piliostigma species in ferugino-tropical soils in the Sudano-Sahelian zone of Burkina Faso, West Africa

Abstract

In the Sudano-Sahelian zone of Burkina Faso, Piliostigma reticulatum (DC) Hochst and Piliostigma thonningii (Schumach) are precursor species of fallow land colonization and they are used by rural villagers. The present study aimed to assess the contribution of Piliostigma species to soil quality improvement. We quantified organic carbon, total nitrogen, soil microbial biomass, soil basal respiration and metabolic quotient from soil samples taken under and outside Piliostigma canopies. We used one-way ANOVA to test for differences in the above parameters between locations (beneath and outside Piliostigma canopies). We recorded increased total organic carbon under Piliostigma from 31%–105% and in total nitrogen from 23%–66%. Microbial biomass was 13%–266% higher beneath canopies as compared to outside canopies. Basal respiration was also higher beneath canopies. The chemical elements varied by class of soil texture. Metabolic quotient (qCO2) was significantly correlated to clay (r = 0.80) and silt (r = 0.79) content. Piliostigma stands produced abundant litter due to their leaf biomass. Thus, they contribute to improved total organic carbon and total nitrogen content in the different phytogeographic zones and improve soil fertility.