| Popis: |
A mixed-crop plot of cocoa and kola at Cocoa Research Institute of Nigeria, Ibadan was resolved into four different randomized planting arrangements. Thereafter, soil samples were collected under them and analysed for bulk density, total porosity, particle size distribution, pH, organic matter, nitrate nitrogen, available phosphorus, calcium, magnesium, potassium, copper and zinc. The application of ANOVA and LSD statistics shows that the planting arrangement in which a kola stand is close and adjacent to two cocoa stands in a row (D) is the most beneficial to topsoil chemical properties when compared with other arrangements: row of kola between two rows of cocoa (A); single row of cocoa between two rows of kola (B); two rows of cocoa (C). The results imply that soil fertility status was best maintained under D. The major reason advanced for this situation is the synergistic relationship among the organic materials of both cocoa and kola, culminating in a high level of soil organic matter content and which did not occur under other planting arrangements which were more or less monocultural. The present exercise appears to point to the fact that interplanting cocoa and kola to a specified pattern (a sort of tree-crop agroforestry) could be advantageous to soil fertility status, and might be easily adopted by peasant farmers since neither chemical fertilizers nor mulches would be required to maintain soil fertility. |
