Evaluation of Innovative Cultivation Practices for Optimizing Soil Fertility, Crop Yields and Soil Microorganisms in Western Niger

The environmental situation in Niger is alarming. It is characterized by droughts, floods, and irregular rainfall, leading to a decline in agricultural production and food insecurity. These issues are exacerbated by climate change, desertification, and unsuitable farming practices. The poverty of farmers limits the use of chemical fertilizers, which are also known to threaten and degrade soil sustainability over time. Moreover, their high cost compared to the purchasing power of Nigerien farmers poses an additional challenge. As a result, Nigerien farmers have no choice but to seek more sustainable alternatives. Mycorrhization could be a viable solution, as it represents a promising strategy for restoring soil fertility and improving agricultural yields. Mycorrhization creates a symbiotic relationship between fungi and plant roots, enabling the absorption of nutrients and water while enhancing plant resistance to stress and diseases. This approach reduces the use of chemical fertilizers and pesticides, thus promoting soil health and fostering more sustainable and economical agriculture. Three experiments were conducted: In Sadoré: Research was conducted to identify legumes that could serve as good precursors to millet cultivation and promote mycorrhization and soil fertility. The legumes used were sesbania, dolichos, and cowpea. In the W National Park region: Methods were explored to enhance mycorrhization, facilitate the proliferation of arbuscular mycorrhizal fungi (AMF) spores, and improve root colonization. The study revealed that bacteria such as Pseudomonas spp. thrive with practices like corralling and manure application, while mulching proved particularly effective in promoting AMF spore proliferation and root colonization. These practices—especially manure application, corralling, and mulching—improved millet yields, with mulching having a long-term positive effect on both grain and straw production. In Saguia: Research focused on the use of organic fertilizers, particularly high-dose poultry manure, which resulted in high tomato yields while improving soil stability through an increase in glomalin levels. These findings highlight the importance of adopting appropriate agricultural practices to restore and enhance soil productivity in Niger through the action of symbiotic microorganisms.