Agro-Pedological Characterization of Cashew Plantations (<i>Anacardium</i><i> </i><i>occidentale</i><i> L.</i>) in Casamance, Senegal

In Senegal, the agricultural production system is dominated by rainfed crops, and the tree-crop association is an alternative for sustainable production. The introduction of high value-added woody species into the agricultural space should be one of the solutions for ensuring diversified and sustainable agricultural production. Cashew (<i>Anacardium</i><i> </i><i>occidentale</i><i> </i>L., Anacardiaceae), which plays an important role in Senegal's agricultural sector, could be one of the species with high agroforestry potential, but has been little evaluated. The present study aims to contribute to understanding the importance of agroforestry species in agricultural production by characterizing the physicochemical fertility level of soils under cashew tree cover and establishing their cultural aptitudes. To this end, 18 samples were taken from 2/3 of the cashew tree crown radius at two depths, 0-20 and 20-40cm, in different production zones (Kolda, Sédhiou, Ziguinchor) in Casamance, characterized by the presence of poorly developed, ferralitic and hydromorphic soils. The results indicate a silty-clay-sandy texture of the soils in these regions. The texture of the 0-20cm horizon is also silty-clayey-sandy. However, the 20-40cm horizon has a sandy-clay texture. The soils are highly acidic (pH<5), with significant differences between regions and horizons. The highest values for pH, P/Ass, MO, CE, KCl, C, C/N were found in Kolda. A highly significant effect was detected between horizons. The 0-20cm horizon gave the highest values for MO (00.43±0.08%), CE (67.36±1.76), KCL (4.30±0.08), pH (4.69±0.09), P/Ass (2.77±0.45 ppm), C (13.33±0.76%), C/N (13.22±0.72). It appears that variations in pH (water, KCl) are strongly, positively linked to those in EC, C and OM, but negatively linked to clay. These results show that cashew soils are rich in mineral elements. However, it would be interesting to see whether soil properties are influenced by <i>Anacardium</i><i> </i><i>occidentale</i><i> </i>L., and to learn more about the species' acidifying properties.