Barley

Barley is a cool-season annual bunchgrass grown in full sun on well-drained soils, performing best on moderately fertile loams and clay loams; sandy ground causes uneven growth and poorly drained soil is not tolerated. It tolerates a wide pH range of 6.0–8.5 and outperforms other small grains on highly alkaline soils, and has even been used to reclaim saline ground.

With supplemental irrigation the crop does well in cool, dry areas. It is more winter-hardy than oats but less so than wheat or rye, and plants are killed once temperatures drop below 17°F, which limits its planting window and range. As a cover crop it is sometimes grown alongside nitrogen-fixing crimson clover, since barley itself does not fix nitrogen but produces enough root and top growth to add organic matter to the soil.

Barley becomes more susceptible to diseases and pathogens in hot, humid climates, which is part of why it is not typically grown in the humid southeastern United States. It is also susceptible to southern root knot nematode. Unlike wheat, it does not host Hessian fly, sparing it that pest and making it a useful crop to grow ahead of wheat in a rotation.

Culinary: Barley grain is grown for both human and animal consumption and ranks fourth in world grain production behind maize, wheat, and rice. In the United States it is used mainly as a high-protein feed additive for cattle, sheep, pigs, and poultry, while an estimated 25% of the crop goes into malted beverages such as beer. It has long been a food staple in the Andes of Peru and the high plateaus of Tibet, among the few cereals able to withstand high elevation and short growing seasons, and barley flour is also used in breads, noodles, pasta, and other cereal-based foods.

Forage: Like other small grains, barley can be grazed by livestock before seedheads form, and because it can be planted earlier than wheat it provides early-season grazing. It uses water efficiently, making it a valuable forage during drought, with silage yields of around 2.5 tons per acre of dry matter.

Cover crop: Barley is also grown purely to maintain soil quality, since it is not harvested but instead terminated before maturity, limiting erosion, suppressing weeds, and adding organic matter to cropland.

Ornamental: Its narrow, awned seedhead is sometimes used in dried floral arrangements.

Barley is one of the earliest cereals brought into cultivation and does not occur in the wild, and its precise origin remains uncertain. It is thought to descend from Hordeum spontaneum, a weedy relative widespread across the Fertile Crescent of the Near East, though Hordeum agriocrithon, discovered in Tibet in 1938, has also been proposed as a closer ancestor to modern cultivated barley. From these long-farmed regions cultivation spread along ancient trade routes across the world, and once a domesticated two-row form existed, farmers selectively favored the six-row form that arose from it.