Short-term influence of cowpea crop and mineral fertilization on the spatial and temporal distribution of soil microbiological and chemical properties

The role of cowpea in improving soil fertility has been extensively studied at the rhizosphere level, yet its impact on bare soil properties remains unclear. Soil fertility management is crucial for sustainable agriculture, particularly in the context of climate change. This study evaluates the short-term effects of cowpea and mineral fertilization on soil microbiological and chemical properties. Two field trials were conducted in 2021 and 2022 during the rainy season. Soil samples were collected at three depths (0–10 cm, 10–20 cm, and 20–30 cm) from plots where cowpea was grown either as a sole crop or with an additional application of 100 kg. ha ^− 1 of NPK. These samples were compared with those taken before sowing at the same depths. Results indicate minimal variation in soil characteristics across depths. However, bacterial abundance significantly decreased under sole cowpea cultivation and during the cropping season in 2022. A significant reduction in phosphorus levels was also observed in the sole cowpea plots (P = 0.0001). These findings suggest that short-term cowpea monoculture may contribute to phosphorus depletion and reduced bacterial charge, potentially impacting long-term soil fertility. Further studies are needed to assess the long-term sustainability of cowpea-based cropping systems and to explore potential mitigation strategies.