PHOSPHORIC ACID AND SILICA OF PUERTO RICO SOILS

Abstract

One hundred and nine soil types from the humid region of Puerto Rico were classified on the basis of their mechanical analysis into five soil classes—sands, sandy loams, sandy clay loams, clay loams, clays—and were analyzed for pH, volume weight, total and available phosphoric acid and silica. The clay loams weigh about two million pounds per acre plow depth of 6% inches, the sandy loams weigh about 5% more and the clays weigh about 10% less. The total phosphoric acid varies from .051% in the sands to .140% in the clays. The available phosphoric acid varies from .007% in the clays to .017% in the sandy loams. The total to available P₂O₅ ratio varies from 6.3 in the sandy loams to 20.0 in the clays. The total silica varies from 56.75% in the clays to 82.96% in the sands. The available silica varies from .021% in the sands to .166% in the clay loams.