Bryce Black's 1,800 acres of winter wheat in Kansas looked promising after a late-October rain last year; then a dry winter and spring left the crop without moisture when it needed to establish. He harvested about 1,500 acres and the yield was the lowest since he took over the family's 4,500-acre farm in 2017. 'I'm in survival mode,' he told the Associated Press — and a crop that could be planted once and left for four or five years, saving money, labour and everything else, is what makes perennial grains enticing.

Researchers are working on perennial versions of wheat, sorghum and rice, but the work is slow and adoption hard: perennials yield less, harvesting can be difficult and the market is still small. Kernza, a grain related to grasses native to Europe and western Asia, is the furthest along. The Land Institute in Salina, Kansas, began domesticating it in 2001 and it was first harvested on a farm in 2010; last year it was grown on 3,511 acres in the United States, against 37.2 million acres of wheat.

The case for perennials rests on roots that reach several feet down. They tap water deeper in the soil and so ride out short droughts, absorb heavy rain that would otherwise run off and erode the field, and carry carbon deeper into the ground where it is less likely to be disturbed, says Laura van der Pol, the institute's lead soil ecologist. A 2024 United Nations report put the possible cost of soil degradation to the world economy at more than $20 trillion by 2050.

David Mueller of Halstead, Kansas, has planted almost 100 acres of Kernza since 2018 alongside about 600 acres each of corn and soybeans, using it to rebuild soils with drainage problems and restore organic matter. He says the crop needs about a third of the fertiliser wheat does and, planted once every few years, keeps his machinery parked for longer. Some farmers in Southeast Asia and parts of Africa have begun harvesting perennial rice, whose yields the institute says are similar to annual rice.

Yield is the main obstacle, says Lee DeHaan, who leads the institute's Kernza programme: farmers get about 20–40% of a local wheat yield, because a perennial spends energy on roots as well as seed. Cornell University researchers have found establishment difficult in the first year as the crop competes with weeds, seeding rates are still being worked out, yields can fall as a stand ages, and the small grain needs combines adjusted so the kernel is not damaged. Even so, says Cornell's Matthew Ryan, farmers who have lost crops to drought or flood are the ones most ready to build resilience into their operations.

Source: Euronews, reporting by Yolaine De Kerchove Dexaerde and Ruth Wright with the Associated Press