PROPERTIES AND RELATED MANAGEMENT IMPLICATIONS OF MAJOR SOILS IN BUKIDNON, PHILIPPINES

In this study, the soils on the steeplands of Sabacan, Himaya, and San Jose, and on the uplands and alluvial areas of Musuan, were mapped, c haracterized morphologically and chemically, and classified based on t he USDA Soil Taxonomy, The mineralogy of the various soil horizons has been determined using X-ray diffraction (XRD), scanning electron micr oscopy SEM, and transmission electron microscopy (TEM). The soils in t he steepland and upland areas are classified as Typic Hapludalfs and L ithic Dystropepts, The floodplain is occupied by Typic Tropaquepts, Th e pH of the Ap horizons is moderately acid in Typic Hapludalfs and Typ ic Dystropepts and strongly acid in Typic Tropaquepts, The apparent ca tion exchange capacity is very high in these soils, characterized by l ow contents of organic carbon and total nitrogen, a very low available phosphorus and low base status. XRD analysis showed that gibbsite, qu artz, halloysite and hydroxy interlayered 2:1 minerals are present in the clay fraction of all soils, TEM showed goethite as acicular crysta ls extending into pores like needles and lepidocrocite as highly elong ated flakes found abundant in the sub-soils of Typic Tropaquepts.Typic Hapludalfs are deep, well-drained soils suitable for upland cultivati on, Use of light implements would help minimize soil compaction during land preparation, and contour plowing would alleviate soil erosion ha zards on these soils, The coarse-textured Lithic Dystropepts, which ha ve a coherent underlying hard rock material at 50 cm of the mineral su rface, would require proper drainage, A clayey texture and a massive s tructure with redoximorphic conditions pose aeration problems in the T ypic Tropaquepts, These soils could best be utilized for lowland rice cultivation.