Morphological and physicochemical properties of various tropical soils from east-central Puerto Rico

Abstract

This report presents the results of a preliminary soil reconnaissance in east-central Puerto Rico. It contains soil-profile observations made on several deep pits dug for the purpose. It also includes the results of various infiltration tests conducted in the major soil types of the area. The laboratory data reported include organic matter, pH, nitrogen, and total exchange capacity, and also the following measurements conducted on undisturbed soil cores dug with a Kelley (Utah) soil sampling machine: Permeability, quick drainage, water retained at pF 1.78, maximum saturation, and bulk density. Additional data are presented on water retained at pF 2.7 and pF 4.2, available water, total porosity, and air porosity. The soils of east-central Puerto Rico are rather deep, medium- or heavy-textured, acid, and of medium to low fertility. They are not generally well supplied with organic matter and nitrogen. In many cases they have compact, tight subsoil layers near the surface which considerably reduce the permeability of the profile and induce poor drainage. Laboratory soil-moisture studies confirmed field observations indicating that the majority of the soils of this region have a moderately high capacity to store water available for crop growth.