Environmental impact assessment of Finnish feed crop production with methodological comparison of PEF and IPCC methods for climate change impact

• Published in: Journal of cleaner production 2022-12, Vol.379, p.134664, Article 134664
• Main Authors: Hietala, Sanna, Usva, Kirsi, Nousiainen, Jouni, Vieraankivi, Marja-Liisa, Vorne, Virpi, Leinonen, Ilkka
• Format: Article
• Language: English
• Subjects: Climate change impact; Feed production; Global warming potential; LCA; Life cycle assessment; Water scarcity
• ISSN: 0959-6526; 1879-1786
• DOI: 10.1016/j.jclepro.2022.134664

The impact of livestock production on the environment is already well acknowledged. When non-ruminants are considered, the major contributors to products' environmental impacts are related to feed crop production. Feed crop production sustainability is therefore especially relevant in addressing the sustainability and mitigation potential of non-ruminant production. Here, the climate change impact and water scarcity (WS) impact of the current Finnish feed crop production was assessed. The impact of methodological differences on the climate change impact of national-, regional-, and farm-level feed crop production were investigated for utilising the European Commission's Product Environmental Footprint (PEF) guidance and the guidelines provided by Intergovernmental Panel on Climate Change (IPCC). Feed crops selected for the assessment were considered as typical for Finnish pork and broiler chicken production, and included wheat (T. aestivum), oat (A. sativa), barley (H. vulgare), turnip rape (B. rapa ssp. oleifera), pea (P. sativum), and faba bean (V. faba). The farmgate climate change impact varied from turnip rape's 1.22 kg CO2 eq./kg to faba bean's 0.37 kg CO2 eq./kg, while cereals resulted in 0.47–0.63 kg CO2 eq./kg, and pea 0.49 kg CO2 eq./kg according to IPCC methods. Similarly, with PEF methods, the results varied from turnip rape's 1.18 kg CO2 eq./kg to 0.31 kg CO2 eq./kg of faba bean, cereals resulted in 0.42–0.58 kg CO2 eq./kg, and pea 0.43 kg CO2 eq./kg. The absolute difference between methods ranged between −0.045 and −0.068 kg CO2 eq./kg. The analysis showed that even if the relative error varied from 3% to 19% between methods, the relative order was the same, independent of the methods. The farmgate WS impact of Finnish feed crops was 0.23 m3 eq./kg for turnip rape, 0.05 m3 eq./kg for faba bean, 0.08 m3 eq./kg for barley, 0.08 m3 eq./kg for oat, 0.09 m3 eq./kg for wheat, and 0.06 m3 eq./kg for pea. It was observed that the PEF and IPCC methods functioned similarly in distinguishing better and worse performing crop production between cases. It was shown that the major contributors to feed crop production in Finland were energy and input production, N2O from N inputs, and peat soil degradation. The amount of N2O emissions from peat soil degradation especially demonstrated high variability and was therefore identified to have high mitigation potential. The investigation demonstrated the importance of including N2O emissions in the widest form whe