Adaptação do sistema de capacidade de uso das terras aos níveis de manejo definidos pela aptidão agrícola para Minas Gerais

Abstract

A farming system is a way of organizing the natural, technical and human resources needed for agricultural production, depending on local availability and social demands. Natural, cultural, social, economic and political factors condition their characteristics. In developing countries there is great technical variability in farming systems, from the traditional ones whose primary objective is the subsistence of the farmer, to the intensive ones including capital and technology, integrated to the market. Each farming system has different technical possibilities to face the limits imposed by the environment on production. Therefore, land classification systems need to have sufficient flexibility to meet the demands of different farmers and farming systems. The land use capability system was developed to only serve the farmers with high or moderately high level of management. For this reason, the objective of this work was to develop land use capability classification criteria adapted to farmers with a lower management level. They were applied under field conditions and validated by a new method that uses erosion as the indicator variable. At the end, the land use capability of the state of Minas Gerais was mapped considering three levels of management. The source of information in the first phase of the study was the survey of the physical environment and, in the second phase, the soil map of the state of Minas Gerais, at a scale of 1:650,000. In both phases a geographic information system was used to elaborate the maps. It was verified that the erosion is a good indicative of the adequation of use and, indirectly, of the land use capability. The application of adapted criteria increases the correspondence between the maps of adequation of use and erosion, when compared with the criteria currently in use. It was also found that even though the state map of soils is elaborated on a small scale, the accuracy of the mapping indicates that the resulting land use capability map shows sufficient quality for use in regional planning studies, specifically in the initial phases in which the level of detail required is lower.