By Daniel Kindred, Head of Agronomics at ADAS
Most people, even farmers, believe that high crop yields require lots of fertiliser and other inputs that worsen the environmental impacts of farming. After looking at this during the biofuels debate in 2008, we in ADAS were not so sure, so the Morley Agricultural Foundation recently funded us to explore the evidence for these assumptions with respect to greenhouse gases (GHG). We used a new dataset created by entries in crop yield competitions organised by the Yield Enhancement Network (YEN) since 2013. This analysis is our initial step in developing a new YEN called YEN Zero, which aims to provide a community space to share ideas and experiences, to benchmark GHG emissions, and to energise progress in farming towards Net Zero.
Climate change and the National Farmer’s Union’s commitment to Net Zero has soared up the farming consciousness over the past couple of years. The issue last heated up around 2008 with policies promoting the introduction of biofuels to replace petrol and diesel. This was when we began to appreciate how increasing the demand for crop production encouraged the conversion of land globally from natural vegetation to cropping. Through working on the Gallagher Review, which examined these effects, we quickly realised that these issues apply just as much to food production as to biofuels.
While agriculture is responsible for around 11% of the UK’s GHG emissions it is also the only industry whose primary function is to remove carbon dioxide from the atmosphere, through photosynthesis, to produce energy rich products. Agriculture can therefore not only reach Net Zero emissions, but uniquely, it has the potential to go net-negative!
Understanding, quantifying and reducing the GHG footprint of cropping is going to become increasingly important in the coming years as the farming industry strives to reach ‘Net Zero’. There will be opportunities for arable farmers to play a role in mitigating climate change through practices and technologies that reduce emissions and that lock up carbon in the soil, or by converting more marginal land from production to carbon storage. It will be crucial to this quest that the underlying GHG calculations are open and transparent, that they have consensus across the industry, and that they appropriately reflect the real global consequences of decisions made on each farm. They need to avoid the potential for ‘game-playing’, by reducing emissions on paper without having a real effect, and they must not disincentivise practices that are good in reality but look poor on paper. Where there is a change in quantity of production, the full consequences of that change need to be considered, including consequences on indirect land use change elsewhere in the world.
It is great that many farmers are now using the range of available carbon calculators (e.g. Cool Farm Tool, Agrecalc, Farm Carbon Calculator) to assess their GHG emissions and potential for mitigation. However, it will be important for users to understand the significance of the assumptions made by each calculator so they can achieve the comparisons that they want.
Having led the use of benchmarking in the YEN to understand yield determination on farms, ADAS now can see the potential power of utilising the same approach to address the opportunity to reach Net Zero. There is a prospect of bringing together a community of interested farmers, advisors, industry, researchers and policy makers, to develop shared understanding, to share ideas and data, to enable comparisons and benchmarking, to derive insights and to form hypotheses that can be tested on-farm.