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Waves crash against the rugged Orkney shoreline. A gust of wind whips over the exposed landscape. Tall ancient grains stand in a nearby field, a cacophony rising as the wind blows through their elongated whiskers. As if in submission to this barragement, they bow over with their heads lowered. But this is not an act of submission, it is one of resilience, shielding the precious grains from the harsh conditions. This is a field of bere barley, an ancient variety of one of the UK’s most widely cultivated crops which uniquely is almost exclusively grown on the Orkney Islands in Scotland [1]. The archipelago sustaining this varietal is known for its neolithic heritage sites, distinct dialect, and some particularly challenging weather conditions. After many generations of growing here, bere barley has found itself well suited to its environment, and despite its comparatively low yield, Orcadians remain the custodians of this unusual varietal due to the low input requirements.
There is a growing interest in ancient, locally adapted varieties of key crops like bere barley, but to understand why, we need to consider the modern picture of agricultural resilience in the UK. The typically temperate climate of the UK is set to change as we have been made explicitly aware of this summer, through recurrent heatwaves, wildfires, the dusty yellow colour of the scorched grass evoking a national nostalgia for the UKs characteristic green pastures. This year, the arable harvest in the UK could be reduced by as much as 18.5 million tonnes [2], with crop failure on this scale gaining significant public attention as a foreshadowing event highlighting UK food security as a growing concern. The changing climate requires our crops to change too, a challenge which could be met by harnessing genetic diversity maintained through the likes of bere barley.
To combat the threat of food insecurity, past solutions have focussed on improving our staple crops (for example think: wheat, rice, maize). Historically, farmers have recurrently selected high performing individuals, saving their seeds for the coming year. Ultimately this has facilitated the “genetic gain” or improvement of these crops allowing for high yields that have been able to mitigate food crises. Crucially, a side effect of this has been a significant reduction in the total genetic pool, i.e. a lack of diversity of genetic material within these high performing varieties. This reduction leaves the handful of crops that we are highly dependent upon in a hugely vulnerable position when faced with the unpredictable impacts of climate change on agriculture.
Perhaps the most famous example of this intensive narrowing is the Cavendish banana – a variety which is now farmed almost exclusively. Due to its uniformity, it is favoured for scalable farming practices and providing a predictable appearance and flavour to consumers. Because this monoculture lacks diversity, there is very limited resistance to new stresses. Once the Cavendish banana is threatened by a disease it is susceptible to, all individuals are at risk of succumbing to the disease, facilitating rapid spread through dense plantations which could ultimately wipe out this beloved fruit. This was the case when TR4, a soil dwelling fungus, came on the scene first occurring in Asia, and spreading to Latin America in 2019 threatening banana production [3]. This has meant an increase in chemicals required to grow banana plants, which now ranks second to cotton for consumption of agrochemicals [4].
The parable of the Cavendish banana teaches us that we have an obligation to maintain, protect and implement genetic diversity in our favourite foods if we want them to survive the present and future environmental challenges. Thinking back to bere barley, we know that diverse genetics allow for the exploitation of diverse ecological conditions. Ultimately genes, such as those from landraces, can be considered as an indispensable toolkit for the adaptation that will be required under extreme and unpredictable environments if we want to keep growing food. Evidence of this urgency can be found in seed banks, which are devoted to the conservation of edible species thus preserving crop diversity around the world. Reminiscent of a scene from an apocalyptic sci-fi film, the most extensive collection is harboured deep inside the permafrost of the mountains of Svalbard, a Norwegian archipelago located halfway towards the North Pole [5]. However it is not just diversity within the same crop that is essential if we want resilient, future-proof food, we must also consider the variation that exists in the range of different crops that might be grown.
In the UK arable land is overwhelmingly dominated by the cultivation of just three major crops – wheat, barley, and oilseed rape [6]. To paint a picture of the domineering place of wheat in UK agriculture, around 2500-fold more land is used for wheat cultivation than other arable crops combined (excluding barley and oilseed rape).
Lack of diversity is mirrored at a global level; of the 12,650 edible plant species [8], just 7,000 species have ever been used by humans as a significant source of food and nutrition [9]. This means that, presently and historically, we have utilised just 55% of potential food crops. As the world moves towards a global standardised diet, and the global standardised farm, we become ever more dependent on the same narrow selection of major crops. Compared to the combined historical and contemporary use of around half of all edible plant species, a perhaps more realistic current estimate is that just 30 plants make up our major caloric intake, with 60% of those coming from rice, wheat and maize alone [10]. Diversification is better for diet, protection from market disruptions, ecosystems, soil health, and ultimately is essential to future food and nutrition security.
To mitigate the impact of climate chaos, UK agriculture will need to diversify the crops grown. This diversification is key to disrupting pest and pathogen cycles, either in a spatial sense breaking up consecutive fields of monocultures, or in a temporal sense through rotating through a range of crops in one field. Diversification might look like welcoming plants that become well suited to the UK as the climate warms, including grapes or stone fruits like peaches [11]. Another angle on crop diversification is to utilise the aforementioned edible plant species which are not broadly cultivated or commercialised. These are sometimes referred to as orphan crops (or perhaps more optimistically, as opportunity crops) and are often rich in genetic diversity, with local varieties and their wild relatives harbouring genes that make them well adapted to a range of conditions [12]. Another benefit is their high nutritional density, partially thanks to a lack of recurrent selection for yield, which is thought to have diluted the nutritional content of some major crops [13]. Broadening our focus from yield to encompass nutritional content needs to become central to food security efforts considering that hidden hunger (a form of malnutrition where there is sufficient energy intake, but a lack of micronutrients) is already estimated to affect more than two billion people worldwide.
As always with matters of food, this is also a story deeply intertwined with culture. Landraces of key crops, and underutilised orphan crops have traditionally been looked after by indigenous farming communities. As much as the influence of these communities has shaped the trajectory of different crops – think of varieties of potatoes which are good for roasting versus mashing, apples that we prefer baked to raw, or grapes suited to different wines – we are in turn influenced by the cultural impact of these foods. Online registries such as Ark of Taste highlight the wealth of traditional food crops and products from across the globe, including a special flour made from bere barley and dozens of banana varieties. This inventory shines a light onto the existence of these products and acts to incentivise their protection, emphasising that the loss of crop diversity is not only genetic, but cultural. In turn, efforts to maintain these at-risk foods are essential to both people and the planet.
Eva Pears is a PhD student in plant sciences at the University of Cambridge, with an interest in agrobiodiversity and sustainable food. She has can be found on blueksky at evapears.bsky.social.
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References
[1] ECPGR: Landrace
[2] Harvest progress across the UK, reports and interactive tool | AHDB
[3] Michael Gross,The trouble with bananas,Current Biology,Volume 32, Issue 21,
2022,Pages R1201-R1203,ISSN 0960-9822,https://doi.org/10.1016/j.cub.2022.10.033.
[4] The Problem With Banans | Environmental & Social Issues in the Trade
[5] Svalbard Global Seed Vault – regjeringen.no
[6] Diversifying the UK Agrifood System: A Role for Neglected and Underutilised Crops
[7] Agricultural Land Use in United Kingdom at 1 June 2025 – GOV.UK
[8] Plants for Human Consumption: An Annotated Checklist of the Edible Phanerogams and Ferns, Kunkel (1984)
[9] Hammer, K., Arrowsmith, N. & Gladis, T. Agrobiodiversity with emphasis on plant genetic resources. Naturwissenschaften 90, 241–250 (2003). https://doi.org/10.1007/s00114-003-0433-4
[10] Hammer K., Arrowsmith N., Gladis T. (2003). Agrobiodiversity with emphasis on plant genetic resources. Naturwissenschaften 90, 241–250.
[11] Four UK crops you might be eating in 2035 | Sustainable Food Trust
[12] Talabi AO, Vikram P, Thushar S, Rahman H, Ahmadzai H, Nhamo N, Shahid M, Singh RK. Orphan Crops: A Best Fit for Dietary Enrichment and Diversification in Highly Deteriorated Marginal Environments. Front Plant Sci. 2022 Feb 24;13:839704. doi: 10.3389/fpls.2022.839704.
[13] Bhardwaj RL, Parashar A, Parewa HP, Vyas L. An Alarming Decline in the Nutritional Quality of Foods: The Biggest Challenge for Future Generations’ Health. Foods. 2024 Mar 14;13(6):877. doi: 10.3390/foods13060877.
