Cost-effective approach to explore key impacts on the environment from agricultural tools to inform sustainability improvements: inversion tillage as a case study

The United Nations Food Systems Summit and the European Green Deal have prompted various policy and regulatory initiatives aiming to transition agricultural practices to become more sustainable. An array of agricultural systems (e.g., regenerative, conservation agriculture, integrated crop management) have been lauded as potential solutions to improve food production sustainability. These systems use combinations of agricultural tools (e.g., crop rotation) to modify the crop environment to reduce weeds, pests and disease, alongside chemical (e.g., plant protection products) tools. Each tool has the potential to impact both the abiotic and biotic environment, with different combinations of tools having different overall outcomes. To improve the sustainability of agricultural practices it is important to understand, and where possible, quantify the environmental costs and benefits of the various tools that are applied within diverse cropping systems, as well as their potential interactions. While extensive literature exists, practical approaches are needed to cost-effectively synthesise key impacts and interactions to support decision making. A cost-effective methodology, adapting a rapid evidence assessment, was developed to review evidence and enable identification of the key environmental impacts for commonly applied agricultural tool options. The approach was applied to each tool individually (e.g., inversion tillage, crop rotation) to, where possible, isolate their specific impacts on the environment. Focused categories were assessed, considering biotic (insect, earthworms, etc.) and abiotic (soil, water, air quality, climate) impacts. This paper considers inversion tillage (also known as ploughing) as a case study to illustrate findings using the approach. Evidence is presented for direct and indirect impacts on the environment, selectivity of impacts and data gaps. The approach quickly provided robust evidence summaries of the key environmental implications of inversion tillage, facilitating identification of opportunities and trade-offs that can inform practice. The evidence highlighted how inversion tillage can offer effective weed control to reduce herbicide use, but carries increased risk to soil health, with connected implications for water, air and climate. This time-efficient review methodology can facilitate development of clear guidance to inform farmers in their decision making to improve on-farm sustainability, while serving as a useful starting point for conducting evidence reviews for policy development.