Thinking and doing geography: a contribution to erosion control in rural properties in the municipality of Regente Feijó, São Paulo

Author(s)

Alessandro Donaire de Santana

• Document type: Master's Dissertation
• Institution: Universidade Estadual Paulista (Unesp)
• Defense date: 2017-02-06
• Advisor: João Osvaldo Rodrigues Nunes

Abstract

Throughout history, the dynamics of society have accelerated the degradation of natural resources, and erosions are one of the most serious impacts in geographic space. In Brazil, the characteristics of geo-economic exploration associated with pedoclimatic characteristics have led to the increase in erosion. The western region of São Paulo State has a high susceptibility to the occurrence of such processes due to agricultural practices being performed on soils with predominantly sandy textural characteristics. Therefore, there is a need to develop strategies enabling the recovery or minimization of erosion. The main objective of this research was to analyze geographic space transformations based on the investigation of erosions in the northwestern area of Regente Feijó, São Paulo. The application of erosion control techniques in a rural property allows articulation between theory and practice in minimizing their negative impacts on rural areas. The study was conducted in partnership with a couple of family farmers whose knowledge contributed to the understanding of geographical reality. The technique was based on the Brazilian Agricultural Research Corporation (EMBRAPA), and consisted of the implementation of palisades made with materials such as bamboos, woods, and bags filled with sand in furrows and ravines set up on a broken terrace in a pasture area. Palisades were monitored for 19 months using the graduated stakes technique reported by Guerra (2002). Samples were collected from sediments that were retained upstream of palisades to calculate granulometry and fractionation (EMBRAPA, 1997). Although there was cattle traffic in the area, results from graduated stakes showed that palisades retained a considerable amount of sediments during precipitation and allowed the development of the grass Brachiaria decumbens, which acts as a natural barrier. The granulometric analysis of sediments showed more than 80% of sand in its composition, containing fine and very fine sand (between 65% and 82%). These analyses revealed soil fragility, which has been used to raise cattle for fattening, with a history of land use marked by the adoption of inadequate agricultural practices. These characteristics led to erosion and, therefore, the adoption of control strategies by farmers: restoration of the ciliary forest of streams crossing the rural property and recovery of gullies and ravines, allowing the vegetation recovery. Advances in research have also enabled a partnership with the Coordination of Integral Technical Assistance (CATi), which implemented a project to recover a gully in the property that was grounded and trimmed upstream with containment basins and terraces. Farmers surrounded the area to stop cattle traffic and sowed the land with grass seeds. Despite landscape transformation, preliminary results showed that the intervention was adequate. Geography can help when it comes to creating strategies to face different environmental problems. However, it should be open to the “dialogue of knowledge”, respecting the common knowledge that together with academic knowledge, we can develop actions to minimize negative impacts caused by humans in the production of geographic space. (AU)

• FAPESP's process: 14/20850-1 - Think and produce geography: a contribution to the erosion control in rural properties in the city of Regente Feijó/SP
• Grantee: Alessandro Donaire de Santana
• Support Opportunities: Scholarships in Brazil - Master