The present study was conducted on the site of Boussaragui, rural commune of Chadakori (Maradi). Its general objective is to assess the effects of the practice of Assisted Natural Regeneration (RNA) on the fertility of cultivated soils at this site. To do this, surveys were conducted and soil analyses were carried out on soil samples taken from fields under RNA, under Guiera senegalensis, Piliostigma reticulatum and at the bare ground level. The results of the study show that farms in Boussaragui have an average of 12 members including six (6) active agricultural workers and have 8 ha of arable area. Thus, three (3) years of implementation of the IPSR 200583 project of the WAM-Niger (2014-2016), the surveyed beneficiaries of the said project (10%), had to produce 131.46 ha of RNA in their crop fields. This technology is characterized by a high density of woods (trees - shrubs) ranging from 86 feet/ha in the North to 160 feet/ha in the South of the site, with an average of 119 feet/ha for the site. With a shrub population in which 87.95% of the subjects have a height of between 1 and 5 m, this RNA has a floristic richness of 29 woody species inventoried in crop fields (14 families), including Guiera senegalensis and Piliostigma reticulatum, which are dominant at 70.72%. The study of soils at this site shows that RNA does not have significant effects on the physical characteristics of soils, but it does have significant effects on their chemical characteristics, in particular on pH, Organic Matter, phosphorus, phosphorus, the sum of exchangeable bases and CEC.