To sustainably improve rice production in the Zio valley, this study characterized the soils of the developed area. More specifically, the study: (i) determined the Physico-chemical properties of soils and (ii) analyzed the impact of rice cultivation on these chemical parameters. Thirty-six (36) fields of producers were selected and distributed in the 4 villages of the irrigated perimeter: 10 in Kovié, 9 in Mission Tové; 9 in Ziwonou, and 8 in Assomé. The samples were manually collected at a depth of 0-30 cm and analyzed at the soil laboratory of the Togolese Institute of Agronomic Research (ITRA). Physically, the soils are sandy-loamy in Kovié (100%), sandy-loamy in Mission Tové (56%), clayey in Assomé (57%), and Ziovonou (78%). Chemically, the soils are acidic with an average pH of 5.57. They present low (0.89%) and moderate (1.3%) limitation levels respectively for nitrogen and organic matter, very severe for assimilable phosphate (2.3±0.16 ppm), and cation exchange capacity (4.64±0.26 meq/100g of soil) and severe for exchangeable potassium (0.14±0.01 meq/100g of soil). The study also showed a significant decrease in the quantities of Nitrogen, Carbon, Potassium exchangeable, and cation exchange capacity respectively of 57%, 72%, 56%, and 85% compared to 1964. The adoption of cultural practices having a less negative impact on the chemical characteristics of the soil combined with an update of the adapted fertilization formulas become imperatives to ensure sustainable exploitation of the perimeter.