Sustainable Extensification as an Alternative Model For Reducing GHG Emissions From Agriculture. The Case of an Extensively Managed Organic Farm in Denmark

Abstract

GHG emissions of an extensively managed Danish organic farm were estimated upstream and on-farm. The results were compared to Danish national levels based on land area and output. Overall, the farm emitted 2.12 t CO₂eq ha⁻¹ yr⁻¹. Excluding land use, land use change, and forestry (LULUCF) related emissions, the combined GHG emissions from energy- and agriculture-based activities at the case farm were 47% lower (per unit area) and 12% higher (per unit output), than GHG emissions from Danish agriculture. With current livestock density (0.64 LU ha⁻¹) and crop production area, the case study farm would supply at average 1,466 kcal per inhabitant per day in Denmark, if the farm was scaled up to Danish national level. With a reduction of livestock density to 0.36 LU ha⁻¹ and proportional cropland area expansion for food production (ceteris paribus), the case study farm could supply around 4,940 kcal person⁻¹ day⁻¹, matching Danish national levels (including Danish net food export surplus of 41.5%). Simultaneously, the case study farm would have a better GHG balance per unit area and unit output in food, compared to the rest of Denmark. Hence, the case study farm system could serve as an alternative model for Danish agriculture under a sustainable extensification scenario with lower GHG emissions, while maintaining sufficient output for human consumption.

KEYWORDS:

• agriculture
• greenhouse gas emissions
• livestock density
• organic farming
• sustainable extensification

Notes

1. IPCC (2006) guidelines suggest to assume a default value of 20 years until a new soil organic carbon (SOC) equilibrium is reached if no specific data is available, independent of what land categories are concerned. Although Flynn et al. (2012) find 20 years to be “appropriate for the inclusion of most of the change in soil C stocks” (1624), the time period until a new equilibrium is reached is variable (Post and Kwon 2000; Smith 2008) and users of IPCC guidelines are encouraged to assume longer time scales if data supports this. Nielsen et al. (2011a) suggest 50 years as stabilization time for Danish conditions.

2. Biologically active substance in a pesticide.