Crops That Feed The World | Wheat

In many ways, wheat is a symbol of human evolution. A robust ancient grain that has sustained life on earth for several millennia, the story of wheat goes back to when humans decided to settle down and start farming. But will its longevity help it survive a rapidly changing climate and an ever-growing appetite?

The first wheat eaters

The history of wheat goes back to around 10,000 years ago when our hunter-gatherer ancestors first began cultivating emmer, einkorn, and spelt – predecessors of the grain we know today as wheat. From archaeological studies we know that ancient wheat varieties were first cultivated in the region known as the ‘Fertile Crescent’ i.e., parts of modern-day Middle East and the Mediterranean Basin.¹ These were varieties of ‘hulled’ wheat, requiring milling or pounding to release grains from the husk. In comparison, grains of the modern wheat plant (known as common wheat or bread wheat) can be easily separated from their husks through a far less intensive process called threshing.

Read about the Indian farmers using 10,000 year-old wheat to fight climate change

Between 2000 and 500 BCE, wheat varieties travelled from the Fertile Crescent towards Europe, Eurasia, and North and Northeast Africa.² Aided by human and natural selection, this migration led to the development of new landraces of wheat. During the process of domestication in different parts of the world, landraces developed a variety of adaptive traits that would allow them to thrive in their new environments.³ In the meantime, farmers from the Fertile Crescent region pioneered advanced wheat growing and processing techniques, allowing various culinary applications of these grains.

Farmers cut wheat by hand in Jishan County, China. In 2021/22 the European Union was the top ranked wheat producing country, but China is expected to surpass the European Union's wheat production in 2022/23. (Getty Images)

Wheat consumption today

With a massive production volume of 750 million tons per year, wheat is now a staple food for around 35% of the world’s population.^4,5 Of this production volume, close to 70% is used for human consumption, with 20% reserved for animal feed, and the rest used for other purposes such as biofuel production.⁵ To get to this point, the Green Revolution from the 1940s to the 1960s, saw advanced plant breeding techniques being used to develop high-yielding varieties of wheat.⁶ Thanks to dwarfing genes, these varieties were shorter than typical landrace varieties which would often bend over and break because of their tall stems. Food security improved significantly thanks to the success of these breeding endeavours, even allowing wheat-importing countries like India and Pakistan to become major global producers and exporters.⁶

Nutritionally, wheat is of immense importance as well. Compared to other widely consumed cereals like rice and maize, wheat provides a well-balanced mix of carbohydrates (about 75-80% of the grain), proteins (9-16%), and micronutrients such as vitamin B, calcium, and iron.² Due to its relatively low water content, wheat is also easier to store and transport compared to other cereals. The presence of gluten, a structural protein, lends wheat flour a unique elastic property and allows it to be transformed into a variety of food products.

Climate change versus wheat

Modern wheat varieties bred during the Green Revolution were developed for specific climatic and environmental conditions.⁸ Because of anthropogenically driven climate change, these conditions are expected to undergo drastic changes in the years to come. Yields of modern wheat varieties are likely to be negatively impacted by increased variability of the seasons and frequent extreme weather events.⁵ Additionally, existing wheat farming systems rely heavily on synthetic fertilisers, pesticides, and fossil fuels.³ It is widely agreed among the scientific community that mitigating the negative impacts of climate change will need us to move away from such agricultural practices and adopt sustainable practices instead.³

An ancient grain renaissance

Increasing the genetic diversity of the wheat crop through cross breeding with ancient landraces has been suggested as a way to improve its reliance to a changing climate.^6,9,10 Although not extensively cultivated today, a number of emmer, einkorn, and spelt varieties have been preserved in seed banks around the world. This helps preserve their genetic information and creates the possibility to bring these varieties back into production in the future. Spelt is a great example of ancient grain revival. Once an important traditional crop in in southern Germany, Austria, and Switzerland, spelt disappeared from the region at the beginning of the 20th century.¹¹ However, in the 1970s, agriculture reformists successfully campaigned to reintroduce it in Germany and neighbouring countries and today spelt is back to being an import crop in the region.¹¹

Mediterranean landraces are considered to be an especially important genetic resource because of their documented resilience to drought, pests, and diseases.^12,13 They are also known to have high adaptability to low-input farming systems.¹⁴ These grains offer higher nutritional benefits compared to common wheat and may help fortify it.⁶ However, these landraces are not without their shortcomings. Switching out common wheat for ancient varieties is not always feasible because they are not capable of producing yields high enough to replace the role of modern wheat varieties in feeding our growing population. There is hope though, as advanced plant breeding techniques make it possible to incorporate desirable traits from these grains into the common wheat crop - potentially offering the best of both.