Degradation of the physical quality of the soil is a common problem encountered in agrosystems, particularly in the case of open field cropping systems in the northern areas of Côte d'Ivoire. Thus, the structural stability of the soil, which is a good indicator of the sensitivity to threshing and to water erosion in relation to the accumulation of organic matter, was evaluated in two types of soil (Ferralsol and Cambisol) in cashew orchards, in two villages (Mahana and Sanankoro) producing cashew nuts, located the Department of Touba in the North West of Côte d'Ivoire. The objective of this study is to develop new technical routes that are better suited to further promote the sequestration of organic carbon in the soil. Soil samples were taken from open soil profiles at the two chosen sites to allow laboratory analyzes. The results indicate that the surface horizon of Cambisol (site 1) is more stable (Is = 0.78) than that of Ferralsol (site 2; Is = 1.08) with nevertheless relatively small thicknesses of horizons. The median horizons and those of depth, indicate a mediocre stability (Is vary from 1.03 to 1.62). In terms of the quantity of organic carbon, the estimated values vary from 1.96 to 4.53 t•ha −1 for Cambisol (site 1) and from 1.44 to 3.46 t•ha −1 for Ferralsol (site 2). These values remain relatively low especially at the level of the median horizons and those located in depths. Statistical tests have shown a very highly significant and negative association between the structural stability of soils and the amount of organic carbon in the different horizons. The relationship implies that organic carbon plays an important role in the structural stability of soil horizons under cashew tree orchards.

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Land preparation method and preceding crops affect the evolution of rubber trees. Its ignorance and/or poor execution do not allow the efficient development of the agronomic and economic potentialities of plantations. In order to remove this constraint, a study was undertaken in southwestern Côte d'Ivoire. The rubber trees were planted at 510 trees/ha according to a Fisherblock experimental design, of six preceding crop treatments with three repetitions. Only one latex harvesting system was applied (S/2 d/4 6d/7 ET 2.5% Pa 1 (1) 6/y). The parameters measured were rubber yield, annual average girth increment, physiological profile, sensitivity to tapping panel dryness and sensitivity to root rot caused by the genus Fomes. The results showed that the rate of rubber trees found in the plots was good (90.73± 0.47 %) and had varied with land preparation method depending on the preceding crops. Vegetative growth at tapping (2.05±1.36 cm.year -1 ), and average rubber yield (2053±179 kg.ha-1 .year -1 ) and the rate of tree loss due to the genus Fomes (8.33±0.42%) were influenced by land preparation method. The good productivity, the good physiological state of the rubber trees were characterized by a well balanced physiological profile and a tapping panel dryness rate (3.60 ± 1.74%), independently of treatments. The Agroeconomic results showed that mechanically prepared fallow (813641 FCFA.ha-1 .year -1 ) was the best preceding crop and land preparation method. This technical result has two main interests for the national rubber-growing industry, since it actively participates in the national policy for fighting against deforestation but also contributes to the establishment of a secondary forest by the attributes of the rubber-growing plant cover.