Mapping the ratio of agricultural inputs to yields reveals areas with potentially less sustainable farming

• Published in: The Science of the total environment 2024-01, Vol.909, p.168491-168491, Article 168491
• Main Authors: Bullock, James M., Jarvis, Susan G., Fincham, William N.W., Risser, Hannah, Schultz, Carolin, Spurgeon, David J., Redhead, John W., Storkey, Jonathan, Pywell, Richard F.
• Format: Article
• Language: English
• Subjects: Agrochemicals; Biodiversity; Fertilisers; Honeybees; Pesticides; Wheat
• ISSN: 0048-9697; 1879-1026
• DOI: 10.1016/j.scitotenv.2023.168491

Fertilisers and pesticides are major sources of the environmental harm that results from farming, yet it remains difficult to target reductions in their impacts without compromising food production. We suggest that calculating the ratio of agrochemical inputs to yield can provide an indication of the potential sustainability of farmland, with those areas that have high input relative to yield being considered as less sustainable. Here we design an approach to characterise such Input to Yield Ratios (IYR) for four inputs that can be plausibly linked to environmental impacts: the cumulative risk resulting from pesticide exposure for honeybees and for earthworms, and the amount of nitrogen or phosphorus fertiliser applied per unit area. We capitalise on novel national-scale data to assess IYR for wheat farming across all of England. High-resolution spatial patterns of IYR differed among the four inputs, but hotspots, where all four IYRs were high, were in key agricultural regions not usually characterised as having low suitability for cropping. By scaling the magnitude of each input against crop yield, the IYR does not penalise areas of high yield with higher inputs (important for food production), or areas with low yields but which are achieved with low inputs (important as low impact areas). Instead, the IYR provides a globally applicable framework for evaluating the broad patterns of trade-offs between production and environmental risk, as an indicator of the potential for harm, over large scales. Its use can thus inform targeting to improve agricultural sustainability, or where one might switch to other land uses such as ecosystem restoration. [Display omitted] •Balancing benefits against harm from agrochemicals will aid sustainable farming.•We propose the Input:Yield Ratio IYR to assess this balance for multiple inputs.•We use novel data to map IYR values for different inputs across England.•We find hotspots where the IYR is high for all input types.•The IYR could be used broadly to highlight where farming may be less sustainable.