Explorando os sistemas de produção hortícola sustentável usando a avaliação emergética para restaurar a sustentabilidade regional (2014)

Exploring the sustainable horticulture productions systems using the emergy assessment to restore the regional sustainability

Elisa Sayoko Nakajima e Enrique Ortega

RESUMO

Este artigo mostra o comportamento ambiental de diferentes sistemas de produção hortícola. A avaliação emergética foi aplicada para a análise de três fazendas hortícolas familiares localizadas no Condado de Ibiúna e um subsistema hortícola da Ecovila Yamaguishi no Condado de Jaguariúna, ambos localizados no estado de São Paulo, Brasil.

Para as fazendas de Ibiúna e Jaguariúna, a Emergia total variou de 2,36E+16 a 9,59E+16 seJ ha ⁻¹  ano ⁻¹ , a Transformidade variou de 1,58E+06 a 4,98E+06 seJ J ⁻¹ Nobre Junior (2009) . A análise de todo o conjunto de resultados é que a renovabilidade dos sistemas do Rio de Janeiro é maior do que os sistemas de Ibiúna e Jaguariúna porque esses últimos sistemas respondem às pressões do mercado para diminuir os preços, aumentando o volume de produção usando insumos industriais agressivos de forma mais intensiva.

A conclusão será disponibilizada ao governo da cidade de Ibiúna e à população para promover uma transição para Sistemas Agroecológicos envolvendo a recuperação da biota do solo e da vegetação nativa, a reciclagem de resíduos urbanos e a redução do uso de pesticidas e fertilizantes químicos, a Renovabilidade de 17% a 55%, a Razão de Rendimento Emergético de 1,14 a 2,24 e a Razão de Investimento Emergético variaram de 0,81 a 4,76.

Os valores da Razão de Carga Ambiental apresentaram grande variação, para a produção orgânica de 0,81 a 1,54 e para a produção convencional de 4,77 a 4,88. A Razão de Troca Emergética apresentou ampla variação, de 0,03 a 3,49. Esses resultados foram comparados aos obtidos em uma análise emergética de cinco sistemas hortícolas orgânicos localizados nas terras altas do Rio de Janeiro, um estudo realizado por Nobre Junior (2009).

A análise do conjunto de resultados é que a renovabilidade dos sistemas do Rio de Janeiro é maior do que os sistemas de Ibiúna e Jaguariúna porque estes últimos sistemas respondem às pressões do mercado para reduzir os preços aumentando o volume de produção usando insumos industriais agressivos de forma mais intensiva.

A conclusão será disponibilizada à prefeitura e à população de Ibiúna para promover uma transição para Sistemas Agroecológicos envolvendo a recuperação da biota do solo e da vegetação nativa, a reciclagem de resíduos urbanos e a redução do uso de pesticidas e fertilizantes químicos.

Palavras-chave: Horticulture, Organic agriculture, Agroecological production, Emergy evaluation, Family farming, Environmental loading

ABSTRACT

This paper shows the environmental behavior of different horticultural production systems. Emergy assessment was applied for the analysis of three family-managed horticultural farms located in Ibiúna County and one horticultural subsystem of Yamaguishi Eco-Village in Jaguariúna County, both located in the state of S~ao Paulo, Brazil.

For Ibiúna and Jaguariúna farms the total Emergy varied from 2.36E.16 to 9.59E.16 seJ ha 1 year 1, the Transformity ranged from 1.58E.06 to 4.98E.06 seJ J 1, the Renewability from 17% to 55%, the Emergy Yield Ratio from 1.14 to 2.24 and the Emergy Investment Ratio ranged from 0.81 to 4.76. The Environmental Loading Ratio values showed a large variation, for organic production from 0.81 to 1.54 and for the conventional production from 4.77 to 4.88.

Emergy Exchange Ratio showed a wide variation from 0.03 to 3.49. These results were compared to those obtained in an emergy analysis of five organic horticultural systems located in the highlands of Rio de Janeiro, a study performed by Nobre Junior (2009).

The analysis of the whole set of results is that the renewability of Rio de Janeiro’s systems is higher than Ibiúna and Jaguariúna systems because these last systems respond to the pressures of market to decrease prices increasing the volume of production using industrial aggressive inputs in a more intensive way.

The conclusion will be made available to Ibiúna city government and population in order to promote a transition to Agroecological Systems involving the recovery of soil biota and native vegetation, recycling urban wastes and lowering pesticides and chemical fertilizers use.

Keywords: Horticulture, Organic agriculture, Agroecological production, Emergy evaluation, Family farming, Environmental loading

Introduction

The development of the chemical industry focused on agrochemicals has been an important factor to increase the crop productivity in the last decades; but on the other hand, the intensive use of agrochemicals has become a major threat to the environment and to the social structure (Hole et al., 2005). Considering the ecological and social criticism to the energy-intensive model it has being developed organic techniques in many countries (Stolze and Lampkin, 2009).

In Brazil, during the 70 s, the chemical industry offered a technological package to small farmers in order to promote “economic development”. The intensification of the use of fertilizers, pesticides and machinery did result in an increase of crop productivity (kg ha⁻¹ year⁻¹), but it did not result in more income for the farmers (Lima Neto, 2001).

On the other hand, the world is now questioning the growing dependence of modern farming on non-renewable resources, as agrochemicals. Farm chemicals are questioned on grounds of cost but their widespread use also has implications for animal health, food quality and safety and environmental quality (Altieri, 1999).

The organic farming is an important strategy for sustainable agriculture as it avoids the use of costly industrial chemicals and improves the food crops quality and it provides control along the entire production chain through the certification process required (Castellini et al., 2006). Nevertheless, a discussion on the contribution of organic agriculture to the future of world agriculture is whether organic agriculture can produce sufficient food to feed the world.

The yield in high level organic production can be critical. In particular to the role of legumes, due a crop rotation, a critical issue will be to which extent sufficient nutrients for this crop can be supplied (Ponti et al., 2012).

The organic production models based on the substitution of chemical inputs for biological ones has become a trend in the search for a more sustainable ecological agriculture (Guzmán et al., 2000). The agro ecological movement has emerged to meet both environmental and social issues for small farmers in Latin America (Altieri, 1999). In Brazil, recently family farming began to gain public recognition; until the 90 s it was considered a segment of marginal importance to the concerns of a society focused on the big agriculture based in monoculture (Altieri, 2002, Lima Neto, 2001).

In Ibiúna, a city located 70 km from São Paulo, a big city in Brazil standards, agriculture is a traditional activity. The county has about 73,400 inhabitants and two-thirds of its population lives in the rural area (SEADE, 2009). In recent years, some family farmers concerned with the excessive use of pesticides, soil degradation and motivated by the potential market for organic products decided to adopt the organic farming (Prefeitura Municipal de Ibiúna, 2008).

Ibiúna is part of the “green belt” composed by a group of cities which provides most of the horticultural production that supplies São Paulo city needs. Ibiúna is also responsible for the conservation of the Jurupará forest park which is recognized by UNESCO as a biosphere reserve for the Atlantic Mountains rain forest.

The assessment of the alternative and conventional horticultural systems is important to provide information to decision makers who aim to maintain environmental services and to reduce environmental impacts in that region. There are several forms to assessment the sustainability of agricultural systems, among of them the Emergy which is total energy used to produce biosphera resource. The Emergy evaluation is environmental accounting methods which uses the thermodynamic basis of all forms of energy, resources and human services, and converts them into equivalents of one form of energy, usually solar emergy.

Emergy evaluation has been used to assess agricultural systems. Zafiriou et al. (2012), have studied the white asparagus production in Greece among conventional, integrated and organic farming systems and also the effect of farming to greenhouse gas emissions to decide best management strategies. Hansen et al. (2001) examined a need to expand and develop organic farming system in line with increasing demands for organic food and growing environmental concerns in Denmark in the light of European Policies. In China the agricultural diversification using more intensive techniques was evaluated using emergy indicators (Zhang et al., 2012), the results showed that although economically feasible, the intensification of agricultural activities became environmentally unsustainable.

Lu et al. (2010) evaluated the integrated emergy, energy and economic evaluation of rice and vegetable production systems and the studies showed that long-term rice was the best choice for sustainable development, followed by rotation systems. The emergy assessment of a soybean biodiesel production chain in Brazil showed that the agricultural step uses the highest amount of non-renewable resources (Cavalet and Ortega, 2009).

The sustainability assessment of a large-scale ethanol production from sugarcane in Brazil was calculated using fossil fuel embodied energy analysis and emergy assessment adopting Life Cycle Analysis (LCA) concepts and considering two production phases, farming and industrial processing, resulting in a low renewability (Pereira and Ortega, 2010). In Sicily, it was applied to evaluate resource use, productivity, environmental impact and overall sustainability in red orange production and the results showed better performance for the system in which the use of economic resource is more intense (La Rosa et al., 2008).

Agostinho et al. (2008) used emergy analysis in association with Geographical Information System (GIS) for comparison of three small farms, located in Amparo County, in São Paulo state, Brazil, the results showed that the agroecological farm was more sustainable and that it could be used as a model for small farms in their transition to ecological agriculture.

Wood et al. (2006) compared environmental impacts in an organic and a conventional farm and the results showed that direct energy use, energy related emissions, and greenhouse gas emissions are higher for the organic farm than for the compared conventional farm. Nevertheless, the indirect contributions for all factors are much higher for the conventional farms. Bos et al. (2014) compared organic and conventional performance related an energy use and Greenhouse gas emissions and they obtained similar results.

Ibiúna region is facing socio-environmental problems. Horticultural producers desire a change from conventional to more ecological production systems. The aims of this research is to explore what are the options for horticultural production considered more sustainable, by comparing energy performance of small family-managed horticulture farms.

The research was realized in three properties of Ibiúna: (1) a farm with two subsystems (organic and conventional), (2) an exclusively organic farm, (3) an exclusively conventional farm, and finally, one farm in Jaguariúna County (4) a horticulture subsystem of a complex agroecological farm (Eco Vila Yamaguishi). At the end of this research, the results is compared with those obtained by Nobre Junior (2009) in the emergy assessment of horticulture systems in Rio de Janeiro in order to provide a better profile of horticulture in the Southeast of Brazil.

Section snippets

Methodology

Emergy evaluation was applied for four properties of the State of São Paulo, with data base of the year 2008. Fig. 1 shows the location of Ibiúna and Jaguariúna in São Paulo state, Brazil.

Results and discussion

The diagram in Fig. 2 describes the organic production. On the right, are the contribution of nature, as sun, rivers, wind and rain. On the top of figure are the inputs of resources from the economy, like materials and services. Inside of the square, is represented the organic production system with seeding that following for two ways a green house or a bed. The products are packaged and transported to sell, and these products can also be food to the family and employees. Inside the organic

Conclusion

This research shows that organic and agroecological systems have better thermodynamical behavior than the conventional agrochemical farms. The sustainability, analyzed in terms of renewability, shows that the values obtained in this study is worse than values of the Rio de Janeiro systems, where the farm activities are less intense and the producers do not depend on deals imposed by market.

The environmental and economic public policies in Ibiúna should be able to provide technical assistance to 

Acknowledgments

The authors are grateful: to CNPq (National Council for Scientific and Technological Development) for its financial support, to Antonio Nobre Junior for providing data from his study, to farmers Masami Yoshizumi, Nelson Naoki Nakajima, Ivan Dias Oliveira and Romeu Matos Leite for the information provided about their production systems.

References (29)

• F. Agostinho et al.The use of emergy assessment and the geographical information system in the diagnosis of small family farms in BrazilEcol. Model.(2008)
• F. Agostinho et al.Integrated food, energy and environmental services production as an alternative for small rural properties in BrazilJ. Energy(2012)
• M.A. AltieriThe ecological role of biodiversity in agroecosystems Agric. Eco Syst. Environ.(1999)
• J.F.F.P. Bos et al.Energy use and greenhouse gas emissions in organic and conventional farming systems in the NetherlandsNjas-wagen. J. Life S. C.(2014)
• C. Castellini et al.Sustainability of poultry production using the emergy approach: comparison of conventional and organic rearing SystemsJ. Agric. Ecosyst. Environ.(2006)
• B. Hansen et al.Approaches to assess the environmental impact of organic farming with particular regard to DenmarkAgric. Ecosyst. Environ.(2001)
• D.G. Hole et al.Does organic farming benefit biodiversity?Biol. Conserv.(2005)
• H. Lu et al.Integrated emergy, energy and economic evaluation of rice and vegetable production systems in alluvial paddy fields: implications for agricultural policy in ChinaJ. Environ. Manag.(2010)
• A.D. La Rosa et al.Emergy evaluation of sicilian red orange production: a comparison between organic and conventional farmingJ. Clean. Prod.(2008)
• H.A. LesjakExplaining organic farming through past policies: comparing support policies of the EU, Austria and FinlandJ. Clean. Prod.(2008)
• C.L.F. Pereira et al.Sustainability assessment of large-scale ethanol production from sugarcaneJ. Clean. Prod.(2010)
• M. Stolze et al.Policy for organic farming: rationale and conceptsFood Policy(2009)
• R. Wood et al.A comparative study of some environmental impacts of conventional and organic farming in AustraliaAgric. Syst.(2006)
• P. Zafiriou et al.Analysis of energy flow and greenhouse gas emissions in organic, integrated and conventional cultivation of white asparagus by PCA and HCA: cases in GreeceJ. Clean. Prod.(2012)

There are more references available in the full text version of this article.