Avaliação do ciclo de vida e valoração ambiental de cultivos de milho próximos à cidade de Uberlândia: potenciais impactos socioambientais

Abstract

Agriculture has always been of great importance in the development of society undergoing various transformations, such as the use of inputs and biotechnology, provoking impacts in the economic, social and environmental spheres. This master's research presents a theoretical reference on the agricultural system and the main transformations occurred in its modernization process. Two scientific papers are presented below. The first one, with the objective of analyzing three systems of corn cultivation in four areas, conventional (CC), transgenic (CT1 and CT2) and organic (CO), near the city of Uberlândia, using agricultural inputs, in order to identify and compare the potential environmental impacts caused by the use of fertilizers, pesticides and correctives, through the Life Cycle Assessment methodology. In the second article, the objective was to analyze costs/benefits, resulting from the use of inputs in the four areas mentioned, estimating the costs avoided through the relation of expenses with these products and expenditures on defensive activities, using the methodology of valuation of Avoided Costs. None of the areas required correction. The results indicate that, in general, CT2 was the crop that presented the worst environmental profile due to its higher emissions of substances to the environment and was also the one that presented higher expenses with fertilizers and pesticides, all of which can be justified by the types, varieties and quantities of inputs applied in the area. The CC and CT1 crops, even adopting different seeds in the production process, present the same management practices. On the other hand, CO was the crop that presented lower emissions by using an organic fertilizer that, besides causing less impact to the environment, is a product of low market cost and used in less quantity. In this crop, there was no application of any type of natural pesticide. By estimating avoided costs, replacing synthetic fertilizers and pesticides with organic ones by applying them in the same custom quantity, producers would have an economic gain, as well as environmental benefits. So, one can conclude that the form of management, area conditions and type of input are factors that influence the occurrence of potential environmental impacts, in addition to costs. CO has advantages when compared to other areas, because it uses products that cause lower emissions to the environment, in addition to the low market cost. But its advantages become limited when it comes to yield, because in order to have high yields, as in other areas, larger areas of cultivation would be necessary which would have environmental implications. Yet many producers have been looking for organic practices to make their farming systems more sustainable.