Widening the analysis of Energy Return on Investment (EROI) in agro-ecosystems: Socio-ecological transitions to industrialized farm systems (the Vallès County, Catalonia, c.1860 and 1999)

Abstract

a b s t r a c tEnergy balances of farm systems have overlooked the role of energy flows that remain within agroecosystems. Yet, such internal flows fulfil important socio-ecological functions, including maintenance of farmers themselves and agro-ecosystem structures. Farming can either give rise to complex landscapes that favour associated biodiversity, or the opposite. This variability can be understood by assessing several types of Energy Returns on Investment (EROI). Applying these measures to a farm system in Catalonia, Spain in 1860 and in 1999, reveals the expected decrease in the ratio of final energy output to total and external inputs. The transition from solar-based to a fossil fuel based agro-ecosystem was further accompanied by an increase in the ratio of final energy output to biomass reused, as well as an absolute increase of Unharvested Phytomass grown in derelict forestland. The study reveals an apparent link between reuse of biomass and the decrease of landscape heterogeneity along with its associated biodiversity.

Landscape Agroecology. The Dysfunctionalities of Industrial Agriculture and the Loss of the Circular Bioeconomy in the Barcelona Region, 1956–2009

“…The analysis is then carried out calculating a set of different EROI [2,11,26] and other flow-fund and fund/fund indicators based on the MuSIASEM approach [9]. In particular, the EROI presented are (i) the Final EROI (FEROI), relating the Final Produce (FP) and the Total Inputs Consumed (TIC), which are the sum of Biomass Reused (BR) and External Inputs (EI); (ii) the External Final EROI (EFEROI), relating FP/EI-which represents the relationship between the output and the input to the farm; (iii) the Internal Final EROI (IFEROI), relating FP/BR, which indicates the biomass recycling effort.…”

“…The paper is structured in the following way: next section presents the case study, which is the BMR, composed of seven counties and 164 municipalities for the years 1956 and 2009, the materials and sources used for the analysis and the methods employed. Section 3 presents the results that integrate the Multi-EROI analysis [11,12,25,26] and the MuSIASEM analysis [9], with a specific focus on the nexus between the main agroecosystem funds, the intensity of their flows and the variation between 1956 and 2009. Section 4 discusses the results, in particular, how the proportions between the main funds have changed, allowing for an increase in the relative productivity of specific products-meat in particular-but at the cost of a disintegration of the flows connecting these funds, so that a shift has occurred from a circular flowing of matter-energy towards a "linear" one, resembling an input-output industrial system of a lower agro-ecological quality.…”

More than energy transformations: a historical transition from organic to industrialized farm systems in a Mediterranean village (Les Oluges, Catalonia, 1860–1959–1999)

“…Oluges and another Catalan case study: four townships in the Vallés county with an approximate total area of 120 km 2 (Sentmenat, Caldes de Montbui, Castellar del Vallès and Polinyà) ( Figure 2). Vallès has been widely studied from a historical sociometabolic perspective (Badia-Miró, Tello, Valls & Garrabou, 2010;Cussó, Garrabou & Tello, 2006;Galán et al, 2016Marco et al, 2018Padró, Marco, Cattaneo, Caravaca, & Tello, 2017).…”

Agroecosystem energy transitions: exploring the energy-land nexus in the course of industrialization

“…An initial hypothesis was that pre-industrial agroecological intensification relied on increasing biomass reused and labor to raise final produce, while agricultural industrialization allowed imported external inputs to replace local biomass reused. This hypothesis was based on insights from Vallés County, Catalonia, Spain, which experienced a very particular trajectory of industrialization (Marco et al 2018;Galán et al 2016;Tello et al 2016). Traditional fertilizing techniques involved the labor-intensive burial of biomass in the soil (Bformiguers^).…”