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A proposal to REVIEW the EMERGY METHODOLOGY in order to make possible a PROPER ASSESSMENT of sustainable rural systems. Enrique Ortega, Fabio Takahashi, José Maria Gusman, Luis Alberto Ambrosio.
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A proposal to REVIEW the EMERGY METHODOLOGY in order to make possible aPROPER ASSESSMENTof sustainable rural systems Enrique Ortega, Fabio Takahashi, José Maria Gusman,Luis Alberto Ambrosio Laboratory of Ecological Engineering, Food Engineering School, State University of Campinas,Campinas, SP, Brazil Support:
PROBLEM In the Northern Hemisphere, the agriculture was transformed intoa very simple system due to the intensive use of industrial chemicals and machinery in substitution of biological processes and local labor. Because of that, the emergy assessment of rural systems lost its inherent complexity. PROPOSAL For the correct assessment of ecological farming the excluded factors must be considered.
INTRODUCTION The research at the Laboratory of Ecological Engineering deals with the emergy diagnosis of Food Production and Consumption Systems and the design of new models for rural systems. At the beginning of activities in 1994, the emergy methodology was applied to conventional chemical farming systems. In 1998, the research focus shifted to soybean farming, the most important agricultural system in Brazil. Soybean is produced in many types of farms, some of them are ecological farms.
During the data collection it was discovered that: • In family managed ecological farms, an important objectivewasthe maintenance of local labor; • The native vegetation is preserved because it supplies materials and services to the peasant’s family; • Regional feedback inputs can be renewable or partly renewable; • Ecological farms produce environmental services. • Chemical farms produce deleterious externalities.
It was concluded that there were two main soybean production models, both with two variants: (a) Biological model- agro-ecological farming- organic farming (b) Chemical model- inputs intensive farming- biotechnological farming It was necessary to work with farm typology, a novelty in emergy analysis. In this presentation the farming models studied will be described.
The emergy methodology needs to be actualized, it demands always to be improved! The suggestion of considering the inputs specific renewability was presented at the 4th International Workshop Advances in Energy Studies, in 2002. In the 4th Emergy Conference, which took place in 2006, it was presented the idea that information is the key input for Brazilian soybean system and a form to calculate it. In this meeting, the main contribution is that farm diagnosis should consider impact absorption area using concepts of ecological footprint method and global warming mitigation.
METHODOLOGY HISTORY The first reference to agriculture emergy analysis was a chapter of the book Energy in Agriculture (Odum, 1984). After that, in Emergy Folio #4, Brandt-Williams & Odum (2002) presented a very similar systems diagram. Figure 1 shows the diagram used for the emergy analysis of the Agriculture of Florida.
Figure 2. A systems diagram with 11 inputs and 1 product was applied to 22 crops (Emergy Folio 4. Agriculture of Florida)
In 1997, Brandt-Williams and Odum wrote a paper to explain the procedure to make the emergy assessment of agriculture. This work became a chapter of the book Ecological Engineering and Sustainable Agriculture that was published in Portuguese on the internet. http://www.fea.unicamp.br/docentes/ortega/livro/index.htm www.fea.unicamp.br/docentes/ortega/livro/C03-SherryOdum.pdf The following diagrams belong to this book.
Figure 1d. Resumed diagram showing aggregated flows of inputs and one output.
These two approaches didn’t consider: • The environmental services provided by farm’s preserved forest and wetlands; • Biologically fixed nitrogen and soil minerals mobilized by micro-biota; • That part of production destined to local population; • Recycling; • The possibility of co-products, as for example, second crops; • Waste, emissions, rural exodus, toxic substances, deaths by intoxication, biodiversity loss, human culture degradation and other outputs.
Ortega et al. (2002a, 2002b), concerned with the distortion between reality and emergy indices, proposed the use of input’s renewability for emergy flows calculation and also new indices. Each Material and Service has its own renewability: MR = MiR = (Reni) (Mi) M= MR + MN S= SR + SN MN =MiN =(1-Reni) (Mi) The feedback could have a renewable part (FR) and non-renewable part (FN): F = FR + FN = (MR + SR) +(MN + SN) This perspective is described in the next figures.
Biological model: Agro-ecological farming. Figure 3a. A broad vision of agricultural systems.
Transition to chemical farming. Figure 3b. A broad vision of agriculture systems.
Chemical model: inputs intensive farming. Figure 3c. A broad vision of agriculture systems.
F = FR + FN Figure 3d. Aggregated flows diagram.
Our first idea for a General Model (It includes biological & chemical systems). Figure 4. A new diagram proposed to study agricultural systems (Ortega et al., 2002a, 2002b)
GW Info WT LR Figure 5. Proposal of a more complete systems diagram measuring INFO, GW, WT and LR (Ortega, 2006).
Figure 6. An even more complete systems diagram for an agricultural system.
OUR SUGGESTIONS • To use the renewability of each input in the Emergy Flows and Emergy Indices calculations; • To consider as additional renewable inputs those flows that are produced by biodiversity, such as soil minerals obtained by deep roots and micro-biota and chemicals produced by symbiotic biota;
To develop indicators that measure: • The real productivity without the consideration of top soil erosion and fossil fuel use as positive fact (instead of EYR = (R/F) + (N/F) +1 use R/F instead of ESI =EYR/ELR use B/C=R/N); • Renewable and non-renewable capital; • Internal flows (local consumption, material recycling, internal services); • Human labor quality; • Environmental services loss; • Negative externalities;
(d) To consider Natural Capital, Environmental services, Infra-structure, Financial and Social Resources, Emissions and Waste as new items in the Inputs-Output balance. (e) To consider the value of Information as input, stock and output; (f) To discuss the contradiction of using Transformity Tr = (R+N+F)/E as indicator of viability, because low productivity (E) and high erosion farms (N) could have the biggest values! (g) To consider impact absorption area.
Ex Figure 7. First part of a proposal for a generic diagram.
The second part of the generic diagram: impact absorption area
The completesystem diagram The impact production must fit the impact absorption capacity
The complete system can be represented in a compact form. It can be seen as a fractal.
Interconnected fractals The question is that until today the production-consumption systems have not been planned correctly!
All the human systems have been built without impact absorption area!
What is the size of the impact absorption area in agriculture? (Agostinho et al., 2008) (Siche et al., 2007) (Ulgiati et al., 2001) (Brown et al., 2002) Brazilian watershed It is up to 6 to 13 times bigger than the crop area! Other countries There is an area deficit! Overshoot possibility!
Production (kg/year) Productivity = -------------------------------------------------------- Crop area + Impact absorption area (ha) The farm productivity should be comparedin a proper basis: as a whole system, including complementary area. The agro-ecological farm already includes its impact absorption area as preserved natural area that also produces environmental services. The chemical farm should include the complementary area needed to absorb environmental impact and to produce the environmental services that are lost due to its full conversion to crop land.
2000 kg/year 1000 kg/year Productivity = ----------------------------------------------- = --------------- ha Crop area (1 ha) + absorption area (1 ha) 6000 kg/year 500 kg/year Productivity = ----------------------------------------------- = --------------- ha Crop area (1 ha) + absorption area (11 ha) An example of whole system comparison: Corn production in an agro-ecological farm: Corn production in a chemical farm: This concept helps to explain the so called “Scale Economy” that really works in the opposite sense!
RESULTS & DISCUSSION Agro-forestry (10 years) Conventional extensive low productivity
CO2 Reduction Actual and Projected CO2 Production The End of Oil Actual and Projected Oil Production Decreasing:N/F, ELR, EIR,Tr, EER Decreasing: %Ren, R/F Support a social & ecological perspective for Increasing: %Ren, R/F Increasing:N/F, ELR, EIR, Tr, EER Individualism, capitalismcompetition & exclusion Community solutions
CONCLUSIONS OR RECOMMENDATIONS • If the suggestions proposed here are pertinent, then it is necessary to organize a group to discuss these issues in deep; • Give this group a reasonable time (4-6 months) to discuss on the best procedures for this kind of emergy calculation; • Disseminate the preliminary results among the emergy researchers to obtain feedback; 4. Write a new folio on Agriculture (General Scope)
ACKNOWLEDGEMENTS • Adriana Pires for egg production system research • Teldes Albuquerque for Agro-forestry systems research • Feni Agostinho for discussion and graph preparation of forested area needed to absorb the impact of non-renewable feedback from economy • Mileine Zanghetin for helping in preparation of PowerPoint presentation
