Soil Fertility Improvement by Using <i>Crotalaria</i> Species Combined to Organic Amendment

In Burkina Faso, agricultural land degradation, including soil fertility decline, has prompted the implementation of agricultural innovations to address this challenge. Therefore, this study aimed to evaluate the contribution of four Papilionaceous ecotypes in enhancing the fertility of degraded soils. Experiments were conducted in Noumousso and Arbollé from July to December 2024, using a randomized split-plot design combining ecotypes and organic matter and/or Burkina Phosphate amendments. Amendments were applied in four treatments: T0 (control), T1 (Organic Matter), T2 (OM + Burkina Phosphate), and T3 (BP). Determined physico-chemical properties were: particle size distribution, pH, carbon (C), nitrogen (Nt), total Phosphorus (Pt), available P (P_Bray), potassium (Kt), exchangeable bases (EB), cation exchange capacity (CEC), and saturation rate (SR). The evaluated agronomic parameter was total biomass. Results revealed that the soils at both sites were characterized by acidic sandy-clay texture and low levels of C, N, P, K, EB, and CEC. Cultivating papilionaceous and applying organo-mineral amendments contributed to increased levels of C, available P, and Mg2+, as well as improved SR. Acidity decreased at Arbollé, while showing a slight increase at Noumousso. Interaction between the two factors helped reduce acidity at both sites and significantly increased C, N, and available P contents. The organo-mineral amendment also enhanced biomass production across all ecotypes. At Noumousso, compared to T0, OM, OM + BP, and BP treatments resulted in biomass increases of 64.8%, 73.1%, and 38.6%, respectively. At Arbollé, the corresponding increases were 33.5%, 47%, and 23.4%. On both sites, OM + BP amendment had the greatest impact on improving biomass production, followed by organic amendment. These findings are of great importance to farmers for restoring the fertility of degraded soils. Therefore, the use of leguminous species in combination with organic matter enriched with Burkina Phosphate could be an alternative for improving the fertility of degraded soils.