Soil properties and crop productivity under varying density of planted Piliostigma reticulatum (DC) Hochst in Burkina Faso

Piliostigma reticulatum is widely distributed in the Sahel and plays an important role in the livelihoods of local communities. Its uses include livestock feeding and soil management. However, anthropogenic pressure and adverse climatic factors have led to significant variability and a decline in the species’ density, impairing its potential for soil management.,. To ensure the sustainable soil management determining the optimal planting density of P. reticulatum is essential. This study employed a completely randomized Fisher block design with four shrub densities (0, 500, 1000, and 2000 shrubs·ha⁻¹) in a sorghum-cowpea mixed cropping system. The management method applied to the shrubs was coppicing. The parameters evaluated included shrub aboveground biomass (AGB), soil chemical characteristics and crop productivity (grain, straw, and tops). The results showed that the densities of 1000 and 2000 shrubs ha⁻¹ increased AGB production by 59% and 64%, respectively compared to 500 shrubs.ha⁻¹. The 2000 shrubs ha⁻¹ density enhanced soil organic status with higher levels of organic matter and total nitrogen. Sorghum grain yield increased by 127% and cowpea yield by 56% at 1000 and 2000 shrubs·ha⁻¹, respectively, compared to the control (0 shrubs·ha⁻¹). A density of 2000 shrubs·ha⁻¹ is optimal for sustainable sorghum–cowpea mixed cropping system wtihin Sahelian agroforestry parklands.