More legumes, better health and environment

Farming and eating foods such as beans and peas could improve people’s health and benefit the environment, according to a recent study published in ‘Frontiers in Sustainable Food Systems’. Supported by the EU-funded TRUE and Legumes Translated projects, scientists from Germany, Ireland and the United Kingdom carried out one of the first-ever holistic evaluations of the environmental sustainability of increased legume cropping in Europe.

Unfortunately, European consumers don’t seem to favour these crops. Whereas 14.5 % of arable land worldwide is used to cultivate legumes, in Europe it’s a mere 1.5 %. In the meantime, Europe imports large quantities of soybean as animal feed from countries where its cultivation may be a culprit of deforestation. Introducing legumes to European crop rotations could therefore play an important role in the EU’s Farm to Fork strategy that is part of the European Green Deal – a package of measures to make the economy sustainable.

The study compared the environmental impact of 10 legume-modified crop rotations across 3 different geoclimatic regions in Europe: southern Italy, Romania and eastern Scotland. In all three climatic zones, introducing legumes into conventional crop rotations led to higher protein production and overall nutritional output, while also reducing synthetic fertiliser usage. The researchers concluded that this practice provided human nutrition at a lower environmental cost, with a reduced effect on climate change, resource use, and land and water acidification and eutrophication. “It is a kind of intervention, if you like, that could help deliver some of those objectives for the European Green Deal Farm to Fork,” stated study co-author Dr David Styles of the University of Limerick, Ireland, in an article published in ‘The Guardian’. “And it kind of needs to be consumer led as well, because the farmers aren’t going to plant these crops if there’s no demand.”Legumes have the ability to fix nitrogen from the atmosphere, providing a substantial quantity of the nutrient to following crops and therefore eliminating the need to use nitrogen fertilisers. According to the study, when legume crops were introduced into the typical rotation in Scotland, almost 50 % less nitrogen fertiliser was needed to offer people the same nutritional value. “Synthetic fertiliser nitrogen dominates the carbon footprint for the cultivation of crops. If we can reduce that by increasing legume production, we’re automatically going to massively reduce greenhouse gas emissions,” explained Dr Styles in the same article.

In nutritional terms, legumes are rich in protein, fibre, folate, iron, potassium, magnesium and vitamins, and are healthier than cereals or meat. “Healthy diet transitions can increase environmental sustainability,” Dr Styles observed.

Thanks to its holistic approach, the study could help scientists form a clearer picture of the benefits of legume-modified rotation and offer valuable guidance on improving sustainability. TRUE (Transition paths to sustainable legume based systems in Europe) brings together 25 companies, educational institutions and research organisations from Europe and Africa to realise successful legume-supported production systems and agri-feed and -food chains. Coordinated by the Johann Heinrich von Thünen Institute in Germany, the 18 European partners of Legumes Translated (Translating knowledge for legume-based farming for feed and food systems.) are working to support innovation in grain legume-supported cropping systems and value chains.

For more information, please see:

TRUE project website

Legumes Translated project website