Soil degradation is a major threat to agriculture in sub-Saharan Africa. In the Senegalese Groundnut Basin, this phenomenon particularly compromises the food security of rural populations. This study aims to evaluate endogenous soil fertility management practices in the Niakhar observatory, a representative area of the southern Senegalese Groundnut Basin. The methodology is based on an in-depth survey conducted in September 2024 among 300 farmers selected at random from the 30 villages of the study area (10 farmers per village). The results reveal six main fertility management practices, often combined by farmers: spreading organic manure (25%), millet-groundnut crop rotation (23%), mineral fertilisation (23%), Assisted Natural Regeneration (ANR) of Faidherbia albida (8%), fallow land (5%) and animal grazing (13%). Comparative analysis shows that combined organo-mineral fertilisation is perceived by 52% of farmers as the most effective method for maintaining soil fertility and improving productivity, compared with 34% and 14% for organic and mineral fertilisation respectively. Crop rotation between millet and groundnuts, combined with ANR of Faidherbia albida, helps maintain fertility by providing nitrogen from legumes and increasing the organic matter content of the soil through improved vegetation cover. This study demonstrates the effectiveness of traditional agroecological practices and suggests their integration into sustainable agricultural development programmes. It also recommends strengthening synergies between endogenous knowledge and technical innovations for greater resilience of Sahelian agricultural systems.