The Soils of the Uplands

Abstract

AbstractThe upland soils have elevation of more than 100 m but less than 500 m above sea level. The topography is nearly level and undulating with slopes ranging from 8 to 18 %. The temperature regime is 22.5–25 °C. The soils of this pedoecological zone were developed from different physiographic and different soil parent materials and generally used for the growing of upland crops, tree crops, and agroforest trees with portion devoted to the cultivation of paddy rice, especially on areas with recent alluvium deposited from upland or hilly land through runoff siltation. The alluvial soils developed from sediments deposited at deltas by a river system necessarily begin from the sediment supply zone at the surrounding hills and mountains. In Chap. 2, we discussed about soils that developed at deposition sites. It is inevitable that the same lowland soil series would occur at midstream and possibly upstream valleys. The upland soils developed from alluvial deposits would follow the concept of sediment continuity. Some of the soil series found in the lowland soils would also be observed on the midstream and upstream valleys, but maybe the drainage characteristics, being located at higher elevation, would have improved. But we also expect additional alluvial soil series at the sediment transfer zone not necessarily found at the lowlands (the sediment deposition zone). In addition to alluvial soils, the upland soils developed in situ are further grouped according to their parent materials—igneous, sedimentary, and metamorphic rocks. Tuff materials can also be classified as igneous rock, consisting of consolidated volcanic ash ejected during volcanic eruptions. We have separated the tuff-derived soils from the rest of the soils of igneous parent materials since the archipelago belongs to the Ring of Fire and these soils generate special interest from local researchers; plus the fact that a great portion of Metropolitan Manila is underlain by tuff and these soils are becoming extinct because of urban development. As in lowland soils, we have included unpublished but recognized soil series, more recently established. We also follow the usual delineation between the poorly drained soils which are characterized by presence of redoximorphic features and the well-drained soils.KeywordsClay LoamUpland RiceSoil SeriesSandy Clay LoamInternal DrainageThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.