There’s a reason to dig into legumes

As 2020 draws to a close our hopes have started to be answered with news ofnote-0 Covid-19 vaccines, and we look forward to the return of face-to-face gatherings with loved ones and colleagues. The Covid-19 vaccines will also allow us to re-focus on an even larger and more-persistent existential challenge facing humanity. A challenge that will also be grappled with by world leaders at the 26th UN Climate Change Conference of the Parties (COP26) to be held in Glasgow from November 1-12 2021.

Dr Pete Iannetta is Head of Ecological Food Systems within the Agroecology Group of the James Hutton Institute

Citizens care passionately about the environment and the natural world, and many are left feeling overwhelmed and helpless at the thought of ever-increasing climate extremes. There is however real hope that a big part of the answer lies under our feet, and this is connected to what is on our plates. Changes in the food supply system could make a huge positive contribution to combat climate change and this starts by increasing the quantity of carbon stored in soil, and that will also regenerate good soil-health. Good soil health is not only the foundation of a more sustainable and resilient food system, it also helps stabilise geo-chemical cycles of water, nitrogen and carbon, so helping reduce the impacts of climate change.

What sort of foods can help improve soil health? Crop plants within the ‘legume family’ stands apart in this regard and include species such as peas and beans. These crops need no synthetic nitrogen fertilisers because they use a natural biological nitrogen fixation capability that takes nitrogen gas from the air to make the biologically useful compounds, such as protein to empower growth and development. As part of a diverse and holistic crop rotation legumes help improve soil function and literally put back more than they take out, so reducing greenhouse gases and increase carbon-capture in the soil. Legume species such as clover can deliver similar benefit from its consumption by cattle and sheep, which if reared naturally outdoors on high nature value grasslands can also help combat climate change. Arable and pastoral systems exploiting legumes may also be combined with trees in agroforestry systems to multiply the climate benefits.

Ensuring that food is produced in a way that is good for the environment requires innovation, and a redesign of our food-systems from farm-to-fork. Awareness of these possibilities and the importance of healthy soil is therefore required across the value chain to encourage the necessary management and behaviour changes. Increasingly, consumers are asking questions about the environmental impact of their food choices, and the credentials of the many food and drink which are now marketed as sustainable. Here again, independent evidence and verifiable research is essential to support and direct consumers concerns and their purchasing power. For example, we see this in innovative food and drink products such as the world’s first ‘climate positive’ gin from Arbikie Farm and Arbikie Distillery, which combine their effort in a ‘field-to-bottle’ approach. In this system, scientists work with business in an open and transparent manner to discover that the greenhouse gas emissions are reduced by use of peas. The high level of legumes now cultivated on-farm will help improve the soil, locking in carbon and organic nitrogen, and high-protein spent raw materials are reused in animal feed. This home-grown provision can replace imported soybeans cultivated in what was biodiverse rainforest and cerrado regions of South America.

Many businesses have been quick to realise the commercial opportunities of this shift in consumer awareness and choice. This is manifest in the labelling of many common products, and the ‘language of sustainability’ is tipped as the top 2021 fashion for food and drink marketing. Consequently innovative, responsive research and a robust evidence base remains essential to ensure that claims regarding environmental benefits lives-up to consumers’ hopes.

On Saturday December 5, we’ll join countless others around the world to celebrate World Soils Day, and hope you enjoy a meal that will be as good for you as it is for the environment and nature we all rely on. Happy World Soils Day!

Dr Pete Iannetta is Head of Ecological Food Systems within the Agroecology Group of the James Hutton Institute and co-wrote this article with Hutton researchers Dr Cathy Hawes and Dr Alison Karley, as well as David Michie of Soil Association Scotland. For more information visit www.hutton.ac.uk and www.soilassociation.org