Avaliação emergetica de propriedades agrosilvipastoris do Brasil e da Colombia. / Emergy evaluation of agrisilvopastoral systems in Brasil and Colombia.

AUTOR(ES)
DATA DE PUBLICAÇÃO

2006

RESUMO

The objective of this paper is to make use of the Emergy Analysis in order to diagnose the performance of cattle breeding productive systems and agricultural and silvopastoral systems and use the results to propose production methods that have harmful impacts on the environment. The agricultural and agrosilvopastoral systems (SAPS) is an agricultural modality in which the same area is used for planting grassy plants and low leguminous plants together with bushes trees and agricultural for feeding cattle, which strongly contributes for the change process of Sustainable Development. There are great challenges in the human nutrition field, among which we can mention the demand for products that have a high nutritional quality and are pathogen and contamination-free. This type of products is produced in systems that are nature-friendly and have a clean production process. In these processes, the management gives priority to the good-keeping of rural landscape and to the conservation of natural resources. This project evaluates systems by using emergy performance indexes, considering their environmental, economic and social aspects. These indexes allow the discussion of sustainability and competitiveness and the suggestion of management practices that avoid/reduce environmental damage caused by cattle breeding. One farm in Brazil and three in Colombia have been studied. The Emergetic Indexes obtained were Transformability (Tr), Renewability (%R), Emergy Yield Ratio (EYR), Emergy Investment Ratio (EIR) and the Emergy Exchange Ratio (EER). Besides emergy indexes, profitability and social indexes have also been calculated, such as the number of employees per hectare in each farm. All the productive systems chosen have agricultural production integrated with cattle breeding, have a high density of trees, have natural barriers against the wind, have a low use of herbicide, produce organic products and have cattle feeding from high protein plants. The indexes have been compared in order to analyze which farm are the most sustainable, requiring less financial resources and having higher ecosystemic efficiency. The most important conclusions: (a) The best cost/benefit, social and environmental relation is in systems adopting the agricultural and agrosilvopastoral model and using little agro-chemical inputs, such as the productive system Reserva Natural of civil society El Hatico and Nata da Serra; (b) From the indexes we can conclude that the productive systems that have the highest renewability indexes are: Nata da Serra (50,93%) and El Hatico (47,25%). (c) The Emergy Yield Ratio (EYR) that corresponds to the relation between the total emergy incorporated to the system and the emergy coming from economical input shows that the best results in primary emergy are in the productive systems Nata da Serra (2,04) and El Hatico (1,94). They are more efficient, while the productive systems El Rodeo (1,31) and La Meseta (1,83) show lower indexes, as they still use some agro-chemical inputs. The obtained emergy indicators were compared with those of cattle production revised and actualized from literature.

ASSUNTO(S)

analise emergetica agriculture emergy analysis agricultura sustentabilidade sustainability sistemas silvipastoris silvopastoral systems

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