CHAPTER 2. FOUNDATIONS AND METHODOLOGICAL IMPROVEMENTS ON ENERGY BALANCES 1
5. Application in a long-term case study, the Vallès county (1860-1999)
We present below the first results of the work we carried out to apply all the above calculations of an energy balance in a specific case study.4 The aim here is to illustrate the potential of this tool in order to analyse the relationship between society and nature, and not to carry out an historical analysis of socioecological transition, a subject addressed in Chapters 3 and 4.
This presentation of results is structured for two time points of 1860 (traditional organic system) and 1999 (agro-industrial system). We have accounted all the aggregated data, and the evolution of the indicators, in the system boundaries of the study area delimitated by four municipalities of the Vallès County.
5.1 Case study, Vallès County as a test bench
Here, we present the main features of the case study located in the Vallès County, which will be the main study area thorough the thesis. The Vallès is a small plain between the littoral and pre-littoral mountain ranges of Catalonia, and the four municipalities of the study area are located 30-40 km away from the centre of Barcelona city, within its metropolitan region: Caldes de Montbui, Sentmenat, Castellar del Vallès and Polinyà (Figure 2.3). It is a transect area going from top the hills in the pre-littoral mountains to the centre of the plain that includes different types of soils and slopes with a typical Mediterranean rainfall ranging from some 600 up to 800 mm a year. The four municipalities comprise a total surface of 11,996 ha with a low relief on its southern half, with altitude ranging from 130 to 250 m, but is mountainous on the northern half, with altitudes between 250 and 815 m. It is a well-endowed area of historical sources and maps, with a long-lasting research done on rural history (Cussó et al., 2006; Garrabou et al., 2010;
Garrabou and Tello, 2008; Marull et al., 2010; Olarieta et al., 2008; Tello et al., 2008, 2012).
4 The detailed calculation methodology is explained in Annex I, on the assumptions and sources for energy balances construction.
Chapter 2. Foundations and methodological developments on Energy Balances
In this first example, we chose two temporal sections to illustrate the stages of the socio-ecological transition; the mid-19th century represents the traditional organic agriculture, and the end of the 20th century when the agriculture was fully industrialised.
In the mid-19th century it had a polycultural organic-intensive farm system which, after having experienced a long-lasting process of winegrowing specialization, exported wine and produced only half of the wheat needed for local consumption, importing the rest from inner Spain (Badia-Miró and Tello, 2014;
Garrabou et al., 2009, 2007; Garrabou and Tello, 2008). Following the Phylloxera plague that ravaged all of the vines during the 1890s very few vineyards were replanted, so many small tenants searched for jobs in industry, and farming was reoriented towards selling dairy products and vegetables in nearby cities and industrializing towns (Badia-Miró and Tello, 2014; Garrabou et al., 2008).
Some time after the Green Revolution, in 1999 the prevailing industrial farming was specialised in meat producing in feedlots (Cussó et al., 2006).
5.2 An advanced organic agriculture specialized in vineyards: Vallès c.1860
Figure 2.3 shows the flow diagram of the agroecosystem of the Vallès study area circa 1860. As we can see, this system was an advanced organic agriculture relying on what is now called a Low External Input Technology (LEIT; Tripp, 2008), where the labour flows and other entries coming from the farming community and the whole society represented a very small fraction of the overall set of energy flows. Thus, beyond the solar radiation flow (Rs), which is not accounted for in the balance sheet, the most relevant flows were those of LP, FP and BR, whereas UB was also significant (Table 2.1). We can observe how most of the annual incoming energy (TIC) came from the biomass production of the previous year (Figure 2.4).
If we look at Table 2.1, we can see how, in order to maintain soil fertility we estimated it would have been required to devote 60% of BR flows by means of burial of fresh biomass and charcoal burnt in small kilns on cropland (formiguers; Olarieta et al., 2011). The rest was used as animal feeding. Out of animal feeding, and after the corresponding metabolic bioconversion, farmers got the very important LS of draught power and manure, which in turn were also used to toil and keep up the farmland. Livestock, however, had a very low contribution (LFP) to the total product (TP), of some 0.6%.
Figure 2.3. Slope map of the case study in the Vallès County.
Source: Our own.
Chapter 2. Foundations and methodological developments on Energy Balances
Finally, 48% out of the total biomass production (TP) harvested had to be recirculated again towards the agroecosystem, while 52% was extracted outside as FP. Circa 1860 this FP showed a strong wine-growing specialization, where vineyard products exceeded the local food production accounted in energy terms. This was a time when vine cultivation peaked in the Vallès, shortly before the entry from southern France of the Phylloxera plague (Badia-Miró et al., 2010).
Lastly, it is worth noticing that firewood produce, used as fuel by the Farming Community at home, and as charcoal for industrial activities, had a relevant weight within the FP obtained.
5.3 A livestock specialization detached from the territory: Vallès in 1999
When we move to the situation at the end of the 20th century a completely different paradigm appears (Figure 2.5). While the incoming-outgoing flows of the agroecosystem through BR, FP or UB were kept more or less in the same order of magnitude than before, external incoming inputs (ASI) to the agroecosystem had been transformed, in the long run, into an awesome flow. As we can see in Table 2.1, 15% of these external entries were the energy cost of tractors and other machinery. Yet 74% of them were animal feed used to fatten a huge livestock density that grew up to 241 LU500/km2, against the 7 LU500/km2 that existed c.1860.
This hypertrophic livestock component was kept disconnected from farmland funds, and the lack of proportion between livestock heads and cropland area has led to the existence of a large amount of Livestock Waste. This LW is all that amount of animal dung slurry that exceeded the fertilizing needs of agricultural fields. Pouring it into cropland generated problems of leaching, or at least made it difficult to handle it. The other side of the coin of this livestock specialization through industrial feedlots was the disproportion between the vegetal and animal products (LP vs, LFP) obtained in the agroecosystem: it was practically the same in energy terms—which meant an unsustainable food basket.
Figure 2.4. Flow diagram of the Vallès’ agroecosystem c.1860. Source: Our own.
Chapter 2. Foundations and methodological developments on Energy Balances
Finally, we observe a very significant increase of the UB, but mainly due to the increase of unmanaged forest biomass (Cervera et al., 2017) stemming from forest abandonment. As we will see in chapter 3, this has led to a polarization of agricultural disturbances into two types of land-uses either intensively cultivated or abandoned.
5.4 The changing multi-EROI profiles along socioecological transition
As a final point in this introductory chapter on energy balances, we are going to examine the information provided by the distinct energy efficiency indicators proposed. In Figure 2.6 we drawn the change in these multi-EROI patterns in the two extreme points of the socioecological transition, c.1860 and 1999. The behaviour of each indicator followed different paths. While there was a decrease in the FEROI and EFEROI values, the trend experienced by IFEROI was the opposite.
In the case of FEROI, we estimated a fall in the energy return (FP) on the agroecosystem per unit of the total energy inputs invested (TIC). While c.1860 for each GJ invested 1.03 could had been obtained, in 1999 the return was only 0.22. This meant a very significant fall of energy efficiency that was mainly due to the increase in ASIs, that is, the impact of livestock specialization in industrial feedlots and the corresponding massive imports of feed grain, together with the agro-industrial cropping with mechanization and agrochemicals. This is what our agroecological approach reveals, when internal as well as external energy costs are accounted.
Figure 2.5. Flow diagram of the Vallès’ agroecosystem in 1999. Source: Our own.
Chapter 2. Foundations and methodological developments on Energy Balances
If we analyze EFEROI, we see that the fall was even greater. This is the energy return indicator that does not consider internal costs. Here, we observe a drop from a return of 11.23 GJ for each GJ socially invested c.1860 from outside the agroecosystem, to a return of only 0.25 GJ for every GJ socially invested. This indicator clearly shows how the farm system changed from an agriculture that was a
Table 2.1. Main flows of the agroecosystem in the Vallès study area. Source: Our own.
Units 1860 1999
5. Unharvested Biomass GJ 294,693 561,468
Figure 2.6. Evolution of the main EROI indicators for the agroecosystem of the Vallès study area c.1860 and 1999. Source: Our own.
1.03
Chapter 2. Foundations and methodological developments on Energy Balances
Finally, IFEROI shows the internal effort made to maintain the agroecosystem production over time. This indicator presents in this case study a growing trend unlike the others. Given that here we are measuring the result in terms of FP over the BR flow returned to land, this means that there was a shift towards a lower investment of BR per unit of FP produced, causing it to pass from a value of 1.13 c.1860, to 2.20 in 1999. At first glance this result might seem counterintuitive if we only read it in terms of energy efficiency, thus forgetting the meaning of this circular flow as a reinvestment in the agroecosystem funds. Yet it is consistent with a progressive replacement of BR with External Inputs (EI). No doubt, the Green Revolution has led to a huge increase in external inputs; but it has also led to the abandonment of organic fertilization practices and a lower recirculation of biomass within agroecosystems. This has entailed relevant impacts in terms of biomass available for many farm-associated species, either belowground or aboveground the farmland area considered.
In short, with this brief presentation we aimed at showing the potential of the novel SFS multi-EROI energy analysis of agroecosystems in order to interpret the historical agricultural change from a long-term socioecological perspective. We consider that both its circular flowcharts and the multidimensional energy indicators provide a good starting point in order to understand what has led to a lower energy efficiency of farm systems at present, and which are the key points and bottlenecks to be faced in order to overcome these biophysical and environmental inefficiencies.
However, in order not to fall into a Cartesian vision (i.e. the faith that a whole universe can be described by a set of equations, as Laplace put it), we have to be aware of the limits that any set of indicators used as explanatory variables of real processes have per se. They are key elements to allow for comparability; but, as Georgescu-Roegen stressed (1971), Ecological Economics has to avoid falling into an energy reductionism that would be incoherent with its criticism of the one-dimensionality of the economic analysis carried out by the orthodox Neoclassical Economics that reduces everything to cash flows. This means that we need to contextualise these indicators within the set of processes, patterns and environments from which they have been accounted, in order to attain a systemic comprehension that allows understanding reality in a deeper way.
That is why we consider energy balances only as a starting point for further methodological developments like the ones undertaken in this thesis. Together with the rest of the SFS Catalan Team, we understand them as a tool to be combined with other approaches and disciplines (such as Political Economy, Landscape Ecology, Land-use Planning, Agronomy and Political Ecology), in order to unravel the agroecological impacts on Mediterranean landscapes caused by the socioecological transition from past organic agricultures to current agro-industrial farming. We deem that only by working from a perspective of strong sustainability, taken as a basic epistemological choice, we can really understand and face the socio-environmental challenges of this current unsustainable food system.
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