Saturday, 15 July 2006

Characterization of the Soils and Evaluation of Sustainability Use of the Lands in Distrito Federal, Brazil.

Marilusa P. C. Lacerda, Inara O. Barbosa, Marina R. Bilich, Cristhian S. Ferreira, Aurelio. A. A. Chaves, Fabio A. Carvalho, and Anete D. Meira. University of Brasilia, Campus Darcy Ribeiro, Brasilia, Brazil

The interpretation of the sustainability use of the natural resources needs complex studies, because it demands evaluations of their interrelations particularly that directly related with soils, with occupation and diversified uses. In this work was emphasizing the use for agricultural activities. In studies of this nature, the mapping of soils and lands capability are important activities. The Distrito Federal (DF), in Brazil, presents serious environmental problems in function of the uses and indiscriminate occupations of their lands. This actual scenery needs, then, a revaluation. This work has the objective of elaboration of the environmental characterization of Distrito Federal for the evaluation of the sustainability use of their lands. On the basis of interpretations of the existent maps of soils and lands capability (Embrapa, 1978) and a model of distribution of soils in the landscape of the Distrito Federal, generated in this work, based on correlation studies about geology, relief and soil classes, that allowed the elaboration of the pedologic map of detail (scale 1:25.000) of this region. Maps of actual use of the lands of DF were generated from image of the satellite SPOT, with space resolution of 10 m, through classifications automated in the software ENVI 4.1. The map of actual use of the lands originated was correlated with the pedologic and lands capability maps, allowing to evaluate the adequacy of the installed agricultural activities. The evaluation of the sustainability of the lands in an area as big as for of Distrito Federal is a difficult task that it demands a long time, however, the studies accomplished until the moment, made possible the obtaining of some significant results. The map of soils generated in scale 1:25.000 was fundamental in the elaboration of the environmental characterization, in function of the larger detail of the distribution of soils, especially those of agricultural potential. Oxic Rhodustox dystrophic occupy a great territorial area of Distrito Federal, in the flat surfaces, in the older Surface Geomorphologic of the area. In these soils, usually, annual cultures of grains are installed, mainly soybean, particularly with high technological level, respecting the agricultural adaptation of these soils. Oxic Plinthustox dystrophic take place in larger proportion in plain reliefs, especially in the borders of flat surfaces, also, in the older Surface Geomorphologic of the area. Usually, they present occurrences of ferric concretions that can cause drainage problems interns, what worsens his agricultural potential. The most common use in these areas is constituted by pastures, in accordance with the lands capability. In the Second Surface Geomorphologic, also in plain slopes, dominates the occurrence of Oxic Rhodustox dystrophic with contribution of lands for erosion. In these areas, prevail the urban development, per times disordered, causing visible environmental degradation. In the hillsides of the transition of the older Surface Geomorphologic with the Second Surface, develop Typic Haplustept + Typic Haplustent. In these areas, where the suitable use would owe being of environmental protection, it is verified, also, urban communities development with well-known environmental degradation. The younger Surface Geomorphologic or Third Surface presents mountainous relief, with features of recent dissection. They develop Tropic Rhodustult + Tropic Haplustult + Ferric Haplustult + Mollic Udferralf + Tropic Mollrendent + Typic Haplustept, when the substratum is constituted by carbonated rocks. In spite of the high potential of natural fertility of these soils, the aptitude of the same ones is harmed by the relief conditions. In these areas, verifies environmental preservation, with limited agricultural use. Use is observed basically for native pastures, not providing problems in the capacity of use of these soils. The largest problems of environmental degradation were verified in the settlement of small farmers with cropping of horticulture and annual cultures, usually without use planning and appropriate handling of the soil. These areas are distributed by the whole Distrito Federal, located preferentially close to the urban areas. These areas are small, however abundant, affecting the sustainability of the lands in these areas.

Back to 1.0PA Multiscale Mapping of Soil Properties for Environmental Studies, Agriculture, and Decision-Making - Poster
Back to WCSS

Back to The 18th World Congress of Soil Science (July 9-15, 2006)