We dug a soil pit of 1m x 1m x 1m in a forest dominated by Castilla elastica, a tree for shade coffee introduced in the karst of northern Puerto Rico. We found four soil horizons (designation notes in parenthesis) (A) organic soil matter (E) mineral soil leachate (B) aerobic mineral soil, and (C) saturated soil. The total storage of soil organic matter was 143 Mg/ha. Apparent soil density increased with depth, the ground-water level was between 65 and 80 cm deep, and there were no roots >55 cm deep. This suggests that most of the C. elastica roots are superficial and unlikely to tolerate permanent waterlogging in the soil. Despite the limitation in the amount of soil available to the roots of the forest, the pit stores large amounts of chemical elements necessary to sustain primary productivity. Storages were (Mg/ha): N-13.9, P-4.0 K-1.8, Ca-19.4, Mg 3.6, Mn-15.9, Al-168, Fe-645, Na-1.1 and C-71.7. The soil was rich in N and P and low in K, Ca and Mg compared to other forests in Puerto Rico.
Viera Martinez, Christian A.; Abelleira Martinez, Oscar J.; Lugo, Ariel E. 2008. Estructura y química del suelo en un bosque de Castilla elastica en el carso del norte de Puerto Rico: resultados de una calicata. Acta Científica. 22(1-3):29-35.