Relative erosiveness of Puerto Rico soils

Data are presented here for pH, organic matter, colloids, moisture equivalent, total and aggregated silt and clay, and dispersion, colloid-moisture equivalent and erosion ratios of various soils from Puerto Rico. The purpose of collecting the data was to evaluate the relative erosiveness of these soils. An upland Catalina clay profile with dispersion ratios of 13-20, colloid-moisture equivalent ratios of 0.97-2.26, and erosion ratios of 6-14, lost from 5.3 to 7.1 tons of soil per inch of run-off per acre per year, when in fallow or desurfaced, respectively. But when this soil was planted to sugar cane the losses were reduced to 1.5 and 0.13 tons of soil per inch of run-off when the trash was burned or kept as a mulch, respectively. This lateritic Catalina clay was classed as a non-erosive soil. Three soils of the gray brown podzolic or lithosol group, represented by the Múcara, Cayaguá, and Pandura series gave higher values for dispersion and erosion ratios and lower ones for colloids-moisture equivalent ratios, in their profiles, and consequently were classed as erosive soils. Other lateritic, alluvial and reddish prairie soils were classified similarly with respect to their relative erosiveness.