Trade-offs between higher productivity and lower environmental impacts for biodiversity-friendly and conventional cattle-oriented systems

Abstract

CONTEXTBiodiversity loss caused by livestock production is a key environmental issue. Biodiversity-friendly livestock systems aim to favour biodiversity mainly for its own sake. Environmental impacts of biodiversity-friendly livestock systems have not been studied, nor have trade-offs between higher productivity and lower environmental impacts of these systems. OBJECTIVEThis study aimed to (i) assess the productivity and environmental impacts of a sample of cattle-oriented production systems representing a wide range of external inputs, productivity and consideration of biodiversity; (ii) identify trade-offs among the objectives of lower input use, higher productivity, lower environmental impacts and higher energy return on investment (EROI); (iii) relate the systems' production strategies to the trade-offs identified and (iv) identify perspectives for biodiversity-friendly livestock systems. METHODSThis study assessed the productivity and environmental impacts of a sample of seven cattle-oriented production systems: an agricultural rewilding system (biodiversity-friendly, in England), three suckler beef systems (two of them considered biodiversity-friendly, in France) and three dairy systems (one biodiversity-friendly and one conventional, in France). Life cycle assessment (LCA) was applied to assess six environmental impacts (i.e. terrestrial acidification, freshwater eutrophication, marine eutrophication, land occupation, and in particular, climate change and energy demand) and was combined with calculation of EROI. RESULTS AND CONCLUSIONSPer hectare of land occupied to produce livestock and their feed, production of human-edible animal protein and environmental impacts of these systems increased as energy demand (i.e. input use) increased. Per hectare, human-edible animal protein production, energy demand and climate change impact (considering carbon dynamics) ranged from 5 kg, 90 MJ and −5.5 t CO2-eq., respectively, for the agricultural rewilding system to 239 kg, 20,496 MJ and 8.3 t CO2-eq., respectively, for the conventional French dairy farm. Patterns of trade-offs varied among the production strategies of the farms. The four biodiversity-friendly farms in the sample had low productivity but also low environmental impacts per ha, especially for climate change and energy demand, due to being extensive systems with relatively high self-sufficiency. Biodiversity-friendly farms also had higher EROI than other farms that produced the same products. Using LCA to assess biodiversity-friendly systems, in particular agricultural rewilding, challenges its ability to consider natural baseline emissions and non-provisioning ecosystem services. SIGNIFICANCEThese results emphasise the need to consider the multiple functions of these systems and their overall environmental performances and sustainability. Current economic and social trends may provide opportunities for biodiversity-friendly livestock systems as a possible future for livestock systems.