The analyses conducted in this study assessed the influence of soil chemical properties on the yields of cassava (Manihot esculenta Crantz) and maize (Zea mays L.) under different cropping systems (monocropping and intercropping).
The results showed that total organic carbon (TOC), soil organic matter (SOM), and total nitrogen (N) exhibited generally low variability between cropping systems and across soil depths (0-30 cm), with no statistically significant differences in most cases. However, a significant difference in the C/N ratio was observed in the 10-20 cm layer, indicating variation in the mineralization rate of organic matter depending on the type of crop.
Agronomically, mean yields differed significantly among treatments. Cassava grown in monocropping recorded the highest yield (24.9±7.06 t/ha), exceeding that obtained under intercropping (17.9±8.07 t/ha). Similarly, maize in monocropping showed an average yield of 2.33±0.24 t/ha compared to 1.44±0.26 t/ha under intercropping, confirming the impact of the cropping system on productivity.
Correlations between soil chemical parameters and crop yields revealed that, for monocropped maize, yield was positively correlated with organic nitrogen, TOC, and SOM (r = 0.4-0.5) but negatively correlated with the C/N ratio (r = -0.4). For monocropped cassava, a strong positive correlation (r = 0.9) was observed between yield and nitrogen, TOC, and SOM contents, while the correlation with the C/N ratio was negative (r = -0.7). Conversely, in the intercropping system, the combined yields of maize and cassava were negatively correlated with nitrogen, SOM, and TOC contents (r = -0.9) but positively correlated with the C/N ratio (r = 0.7), reflecting increased nutrient competition between the two species under this cropping system.
