As climates around the world become increasingly harsh and unpredictable, concerns are growing about our world’s food security.
Already, yields of staple crops like maize and wheat are falling in the low-latitude tropics and in dry, arid regions such as the African arid zones and parts of the Mediterranean.
Rich countries are far from immune. Australia experienced a drop in crop yield of almost 30% between 1990 and 2015 due to less rainfall.
While studying dietary diversity in 2011, environmental scientist Morgan Ruelle, now at Clark University, stumbled upon a possible technique that could help stabilize declining crop yields.
This once widespread practice is now only used by small farms in places like the Caucasus, the Greek Islands and the Horn of Africa. Despite being incredibly simple, most of the agroecological community was unaware of it.
Yet farmers have been using this technique for more than 3,000 years in at least 27 countries. It is perhaps even what gave birth to agriculture.
The method involves planting maslins – a combined mix of grains that can include rice, millet, wheat, rye, barley and more – and harvesting them all together to separate or use as one product.
In Ethiopia, for example, where Ruelle discovered the existence of maslins, the duragna contains multiple species and varieties of barley and wheat, all grown together. Locals view the mixture as one culture, using it to make bread, beer, and traditional flavors.
Local farmers have reported that this mix provides at least some yield under adverse conditions, and now researchers have the experimental trials to back up those claims. Working at Cornell University, Ruelle and his colleagues reviewed previous work, showing that maslins offered greater stability under changing conditions. By changing species composition each season, farmers could insure against climate impacts without the need for additional intervention.
“It’s this ever-changing, reactive entity. On its own, it’s beyond the farmer’s control to respond to whatever conditions arise,” Ruelle explains. “So whatever happens, you’re going to be able to make bread with this.”
The process lets the environment choose which species will thrive. And if the environmental conditions continue to move in one direction, the seed mix for the next season will also move in line with this trend.
“It’s faster than evolution. If you only had one weak variety, it would take a long time to adapt,” says ethnobotanist Alex McAlvay today at the New York Botanical Garden. “But if you have multiple species and multiple varieties, those changes can happen very quickly.”
When drought strikes, the resulting crop yield will contain the most drought resistant strains of barley and less wheat for example. But wheat is always there to take over if there is a sudden rainy season.
“If one fails, at least we have the other,” a Georgian priest growing this mix told one of the researchers in 2022.
For some time, researchers have advised moving away from monoculture can be beneficial in many cases, as planting multiple crop types is much better for pest control, fertilization, wildlife health, and sustainability. . However, polyculture is problematic for larger-scale agriculture that relies on machines for harvesting and processing.
Since the same machines can be used to harvest each variety of grain in the mateil mix, the process can be scaled up. Modern industry is also experienced in sorting grain types on a large scale.
Maslins also produce higher yields. In one field trial, wheat and barley together did 20% better than wheat alone and 11% better than barley alone, and another study found that monoculture land use would have had to be increased by 50% to obtain the same result for the same stock mixture over three years.
Additionally, maslins still pass on many of the ecological benefits of polycultures involving entirely different types of plants, such as resistance to disease and insect pests, which would require less reliance on pesticides that cause all sorts of harm to wildlife. .
“I spoke to Israeli scientists who said they never find wild wheat without wild barley,” McAlvay says. “These grains have been co-evolving for thousands of years.”
There is also evidence that early Bronze Age and Neolithic farmers used maslin mixtures such as emmer and spelt or small spelt.
“A mixture of wild barley (Hordeum spontaneousum) and wild oats (sterile avene) was grown in Gilgal, Israel, before either was domesticated,” the researchers write in their paper.
Although there are still many uncertainties to be studied, such as the tolerance that different mixtures might have towards poor soils, McAlvay and his team believe that the maslins could provide enormous benefits at all levels of agriculture, from subsistence to industry, especially in areas already facing harsh climatic conditions. .
“Subsistence farmers around the world have been managing and mitigating risk on their farms for thousands and thousands of years and have developed these locally-tailored strategies to do just that,” McAlvay concludes. “There’s a lot we could learn from them, especially now, in times of climate change.”
This review was published in Agronomy for sustainable development.