In Daloa, Côte d’Ivoire, many coffee and cocoa plantations that have fallen into decline and been left fallow are being reused. In order to prevent the failure of the planned crops, this study aims to determine the biological functioning of these soils, which is essential for developing sustainable management strategies for them. Seven fallows older than ten years were identified. In each of them, a plot of 10,000 m2 was delimited and four monoliths were isolated. Each monolith was sorted in order to extract the organisms, identify them and calculate their density. A soil sample was also taken from each stratum for analysis. The biological functioning of the soil was determined by considering that the density of fauna is an indicator variable of the biological fertility of the soil, which is then correlated with CEC and texture, two variables considered to explain soil fertility in general. The results show that the density of the macrofauna constituting the soil engineers varies little on the sites, maintaining a relationship with either the sand or silt content of the soil, or with the CEC of the soil, or both variables. Soils where the CEC has been improved by the action of fauna are likely to function better and the types of fauna involved have been identified as the main biological actors in the fertilisation of the soils studied.

The present study aimed to determine the variables that distinguish the hydromorphic soils (Gleysols) used in irrigated or flooded rice growing in the region of Bélier in Côte d'Ivoire and to explain the causes of their variability in order to better apprehend their use in a context of precision agriculture. To do this, a quantitative characterization of the physicochemical composition of these soils was carried out. Soil samples analyzed in the laboratory were collected at various locations in the study area on plots currently or formerly used in rice production. The analytical results of these samples were subjected to a principal component analysis that revealed four homogeneous subsets of soils. These subsets of soils were fundamentally distinct from one another by their silt, clay and organic contents which also emerged as their fertility determinants. Thus, the study will have shown the interest for the rice producers of the zone to carry out a preliminary analysis of the spatial variability of the soil parameters before any agricultural development of the soil.

This study is performed on the Ramsar site of Sassandra Dagbego complex that houses important wetlands including the estuary of Sassandra river and mangrove forests. It has for objective to study the state of conservation of this wetland of international importance that is this site Ramsar. Its implementation was made from the exploitation of satellite images at medium resolution (Landsat TM and OLI) and of investigations on the ground. The processing of images on the implementation indices, colorful compositions and supervised classification was used to map land cover in 1986 and 2014 and to analyze the dynamics of natural habitats between the two dates. The results show a dynamic land use characterized by regression over time, mangroves and forests for the benefit of the cultivated and residential areas.