Effects of cashew cropping systems on soil physicochemical properties and tree performance

Despite the rapid expansion of cashew cultivation in Ghana's forest–savanna transition zone (FSTZ), empirical evidence remains limited on how different cashew (Anacardium occidentale L.) cropping systems and farm locations influence soil properties and cashew tree performance. This study assessed the effects of three cashew-based cropping systems, agroforestry (cashew integrated with timber or fruit trees), intercropping (cashew combined with food crops), and monocropping, as well as the spatial distribution of cashew plantation within the FSTZ, on soil physicochemical properties and cashew tree performance. Soil physicochemical properties, cashew growth parameters, and nut quality were systematically evaluated using standardized analytical methods. Results showed that while most of the soil physicochemical parameters measured were similar across the cropping systems and farm locations, soil infiltration was highest in the agroforestry system (0.067 mm s⁻¹), followed by the intercropping system (0.043 mm s⁻¹) and the monocropping system (0.039 mm s⁻¹). Water potential was near zero in agroforestry, while litter fall and leaf mass per unit area were comparatively lower. Stem expansion was greater in monocropping and intercropping, as was the weight of the nuts. Individual nuts from the upper farms weighed 0.96 g less than those from the middle and lower farms. The individual effects of cropping systems and farm locations significantly influenced the physiology and nut quality of cashew plants in the FSTZ of Ghana. Findings indicate that farm diversification, particularly intercropping cashew with food crops during the first ten years of cultivation, can enhance the quality of cashew yield and overall productivity.