ZINC CONTENT OF ALLUVIALS AS AFFECTED BY RESIDUAL SOIL FROM THE UPPER CATCHMENT AREA

Abstract

Residual soils, whose geology is marine and terrestial sediments, have higher available zinc content than those whose geology is marine clastics. These residual soils come from the upper catchment areas of alluvial soil. Available zinc contents of four alluvial soil series, namely Palo, Umingan, San Manuel and Mandaue, were observed to vary with the geology of their upper catchment areas. Alluvial soils derived from the residual soils of marine and terrestial sediments have higher available zinc than alluvial soils derived from residual soils of marine clastics. Two out of 8 alluvial soil types derived from marine and terrestial sediments contain available zinc in amounts lower than the critical value of 1 ppm. On the other hand, 3 out of 8 soil types derived from marine clastics have available zinc in amounts greater than 1 ppm. Zinc deficiency would most likely occur in alluvial soils derived from marine clastics and least likely in alluvial soils derived from marine and terrestial sediments.