Carbon accounting per unit of food and unit of land in food production systems of Argentina

Abstract

Based on the notion of Life Cycle Assessment (LCA), the carbon footprint (CF) is an extensively used concept that quantifies and informs carbon load per unit weight (e.g., kg C/ton food) in the food system. In line with LCA, the CF computes emissions at pre-farm, farm and post-farm stages throughout a given food chain. However, the CF contribution to C accounting may sound incomplete because gains of C by photosynthesis at the farm stage are set aside. The notion of carbon balance (CB), which computes both C emission and capture (e.g., in ton C/ha), may be relevant in food production systems based on the extensive use of land. Because of the high weight that farm processes have on entire food chains, in this investigation we focused the analysis on the farm stage. In order to assess the suitability of CF and CB in extensive food production systems, we analyzed results from CF and CB in 70 surveyed commercial farms distributed across three large climatic regions (subtropical and temperate) of Argentina. The CF and CB of four relevant farming activities (beef, maize, soybean and wheat production) were compared during the year 2019. The comparison yielded contrasting results and opened space for different interpretations: The notion of CF seems to be useful in intensive food-production systems that rely on inputs and activities that depend on a high consumption of fossil fuels. Conversely, CB appears to be useful in food-production systems associated with an extensive use of land and the gain of C through a large plant-photosynthesis platform.