Coupling groundwater availability and soil ability to delineate appropriate land for agricultural uses in the dry tropical ecosystem of Tchéboa (North Cameroon)

Sustainable agriculture in developing countries must be developed on suitable soil and where quality water resources are available. Matching these two prerequisites allows the mapping of the best-suited location for agriculture. Therefore, the present study aims to combine soil ability and water resource availability to delimit the most suitable areas for agricultural practices in the Douka Longo watershed in North Cameroon. During the period from November 2019 to August 2021, several field tests were used to estimate the water resources availability and the soil potential including the infiltration test, the piezometric survey, the recharge study, and the groundwater and soil analysis. The Analytical Hierarchy Process (AHP) approaches and the ArcGIS tools were used to produce the most suitable areas for agricultural practices with the following parameters (groundwater static level, recharge, pH, Na%, sodium absorption ratio, slope, texture, soil pH and cation exchange capacity). The saturated hydraulic conductivity values vary between 12.9 and 126.4 cm/day with an average of 57.1 cm/day, just indicating that the different soil horizons are slight to fairly permeable. The water quality is appropriate for agricultural uses and the annual groundwater recharge is estimated as 383 mm/year, corresponding to 36.5% of the annual rainfall. The groundwater regulatory reserve is estimated as 3.12 × 10⁹ m³. This important reserve is available for irrigation and drinking water supply. The Water resources are available in 46% of the total area of the Douka Longo catchment. The soils are acidic, light, and well-aerated, but do not hold much water and are also low in nutrients. The soil analyses indicated that its characteristics are fairly appropriate for agriculture. 42% of the total area of the watershed is appropriate for agriculture concerning the soil characteristics. Finally, the area with both the highest soil ability and the water resource availability covers an area of 158 km² and represents 23% of the basin. Good agricultural productivity is expected in this zone. Meanwhile, 46% or 311 km² of the study area is classified as partially suitable for agriculture. To support the farmer’s efforts, soil amendment techniques and irrigation infrastructures must be developed here.