A study of the fertility status of the cocoa and coffee soils of Costa Rica

The above data have shown more variation between samples that had different parent material than between the overall averages of the two coffee regions. Nevertheless, the averages for the east central region were lower than the averages for the San José region in all properties except total nitrogen. Within the east central region, the soil samples from the old and young volcanic soils had the highest level of total nitrogen, moisture equivalent and also high base exchange capacities. On the other hand, the soil samples from the alluvial group had the lowest levels for the properties mentioned. Samples from the other groups were intermediate between these two. A very close interrelationship of the properties mentioned above has been seen. There also seemed to be a direct relationship between pH, per cent of base saturation, and total replaceable bases. The soil samples that had the lowest pH values, had the lowest per cent of base saturation, the lowest levels of total replaceable bases and the lowest averages of replaceable calcium. The converse also appeared to be the case The correlations summarized in Table 22 confirm these relationships. The coffee soil correlations were stronger than the cocoa soil correlations and significant relationships were found for the subsoil as well on the surface soil.