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 work assessed some bioindicators of soil quality along toposequences in Gobala (Poro Region of Cote d’Ivoire). Plant communities have been assessed in four steps (i) use plant inventories to document abundance of plants according to index by assigning a numeric score from +, 1, 2, 3, 4 and 5 respectively corresponding to an average recovery of 0%, 5%, 17.5%, 37.5% 62.5% and 85% (ii) identification of the plant species of scale (iii) distribution of different groups by significantly stands by multivariate analysis (iv) research indicator species based on behavioral indicators depending and nutrient availability. Lower slopes were characterized by 3 perennial grasses plants (Aframomum alboviolaceum, Andropogon africanus, Hyparrhenia subplumosa) and 5 woody plants (Hymenocardia heudelotii, Pseudocedrela kotschii, Pterocarpus santalinoides, Vernonia ambigua and Xylopia parviflora). Lower slopes had highest S/T and lowest C/N values of selected soil quality indicators. At middle slopes, 3 perennial herbaceous plants: Pericopsis laxiflora, Chromolaena odorata and Hyptis suaveolens, were indicated highest C/N (8.8) values of selected poor soil quality. At the upper slopes, Terminalia glaucescens indicated sandy soils (77.4%) of selected poor soil quality. Five species: Daniellia oliveri, Andropogon canaliculatus, Crossopteryx febrifuga, Hyparrhenia Rufa and Lippia multiflora, were far from demanding, because they can be found on various types of pedons and in different ecosystems. Further studies should help to refine the various stages of this methodology, including research indicator taxa by IndVal index.

A study on geological, pedological and botanical prospection was undertaken. The main focus was to identify the types of relief, soils and flora which characterize a suitable soil landscape for the growth of Imperata cylindrica. Investigations were conducted in two locations in Cote d'Ivoire (Ahoue and Yaokoffikro), in order to observe the soil landscape and the state of the plant stand. Data was collected from at Ahoue (southern Côte d'Ivoire) and Yaokoffikro (Centre Côte d'Ivoire). The results obtained from this first investigation indicate that Imperata cylindrica needs a fallow type environmental ecosystem with sandy soils from sedimentary (Abidjan) and silico-aluminous (Bouake) rocks. Imperata cylindrica preferably developed in middle and foot slope positions. Therefore, there is a need for more investigations focusing on the influence of soil texture and nutrients contents on Imperata cylindrica occurrence in both ecosystems.