Barley

Barley (Hordeum vulgare) is a fast-establishing, cool-season small grain used widely as a cover crop across the U.S. Growers choose barley for reliable erosion control, strong weed suppression, efficient nitrogen scavenging, early maturity, and good performance on droughty or saline soils, while being easy to terminate compared to some other cereals. (sare.org, sarep.ucdavis.edu)

• Erosion Control: Small-grain covers like barley are among the best for stabilizing soil. Extension syntheses report cover crops can cut runoff by up to 80% and reduce sediment (soil loss) 40–90%; barley specifically is rated “very good” for erosion control in NRCS field fact sheets. (cropwatch.unl.edu, ohioline.osu.edu, nrcs.usda.gov)
• Weed Suppression: Dense cereal residue and a vigorous live canopy reduce weed emergence 75–90% and can reduce weed growth 80–100%. Barley also contributes allelopathic effects that inhibit certain weeds. (ipm.cahnr.uconn.edu, lgpress.clemson.edu, sare.org)
• Soil Structure Improvement: Barley develops a deep, fibrous root system (roots recorded to ~1.8–2.1 m on deep soils), creating macropores that improve aggregation and tilth; increased organic matter and glomalin from living roots enhance aggregate stability. (sarep.ucdavis.edu, cropsandsoils.extension.wisc.edu)
• Water Management: Barley cover increases infiltration and reduces overland flow; vegetated soils can hold roughly 4.2–4.5 inches of water versus 1.5–1.7 inches in tilled, bare soils. Field work in California also documented 23–77% runoff reductions and 50–75% erosion reductions in small-grain cover systems versus bare soil. (ohioline.osu.edu, ucanr.edu)
• Disease/Pest Break: Barley is a non-host for soybean cyst nematode (SCN), so rotating to small grains helps reduce SCN populations over time; one year in a weed‑free non-host can reduce SCN as much as ~50% (multiple years often needed where counts are high). Barley has also reduced root‑knot nematode (Meloidogyne hapla) in rotation in research trials. (extension.umn.edu, ohioline.osu.edu, extension.entm.purdue.edu, sare.org)
• Nitrogen Management: As a non-legume, barley is an efficient N scavenger. Research reported barley captured 32 lb N/ac as a winter cover and lowered soil nitrate an average of 64% across eight sites; typical barley tissue contains about 1.2% N. This helps retain residual N for the next crop and reduce leaching. (sare.org, sarep.ucdavis.edu)
• Biomass Production: Typical dry matter production is about 2,000–5,000 lb/ac in the Midwest, with irrigated or long-season systems (e.g., CA) reaching 6,800–12,900 lb/ac. More biomass generally means better erosion control and weed suppression. (nrcs.usda.gov, sarep.ucdavis.edu)

• Seeding Rate:
• Drill: 50–100 lb/ac (general); in the Midwest, many programs recommend 50–75 lb/ac PLS when drilling. (sare.org, ohioline.osu.edu)
• Broadcast: 80–125 lb/ac when broadcasting and incorporating; for Midwest programs using PLS, 55–75 lb/ac (shallow incorporation) or 60–75 lb/ac (no incorporation). Increase 15–25% for aerial/overseeding. (sare.org, ohioline.osu.edu, crops.extension.iastate.edu)
• Seeding Depth: 0.75–1.5 inches is typical; up to 2 inches in drier soils. Shallow seeding in moist soils speeds emergence and can reduce early root disease. (ohioline.osu.edu, sare.org)
• Soil Type and pH: Best on well‑drained loams to light clays; avoid saturated or compacted areas. Ideal pH ~6.0–7.0 (target 6.6 for small‑grain systems), but barley tolerates moderately alkaline soils and more salinity than other cereals. Severe yield reductions occur below pH ~5.5. (ohioline.osu.edu, cropsandsoils.extension.wisc.edu, sarep.ucdavis.edu, extension.umaine.edu)
• Planting Time (seasonal windows by region):
• Midwest (e.g., Ohio): Reliable establishment Sep 6–Oct 19; plant after the fly‑free date where applicable. Spring barley window is late March–April when soils allow. (ohioline.osu.edu, nrcs.usda.gov)
• Mid‑Atlantic (Pennsylvania): Winter barley latest seeding dates around Sept 25–Oct 1 depending on region; see Penn State small‑grain areas for exact cut‑offs. (extension.psu.edu)
• Southeast (South Carolina): Sow Sept–Oct; barley overwinters and is more drought‑tolerant than oats in this region. (hgic.clemson.edu)
• West:
• Pacific Northwest irrigated sands and valleys: Aim for early fall seeding (early Sept is optimal for winter covers) to ensure establishment before winter; winter barley is a recommended cereal cover. (pnwsteep.wsu.edu, extension.oregonstate.edu)
• California: Plant early fall for best stand and biomass during cool, dry winters. (ucanr.edu)
• Termination (method and timing):
• Follow USDA‑NRCS Cover Crop Termination Guidelines for your insurance/program requirements; in many northern regions termination is at or before planting (or within 5 days), but always confirm local guidance. A general rule of thumb is to terminate cereals 7–14 days before planting corn; soybeans are more flexible and can be planted closer to termination or “planted green.” (extension.umn.edu)
• Chemical termination: Use effective burndown herbicides when barley is actively growing; terminate before flowering for best control. (canr.msu.edu)
• Mechanical: Roller‑crimp cereals at early flowering for reliable kill; mowing or tillage at mid‑ to late‑bloom also works if done before seed set. (extension.psu.edu, sare.org)
• Rotational Considerations:
• Positive: Barley is a non‑host for SCN and can be used in rotations aimed at reducing SCN pressure; multi‑year non‑host periods are more effective where counts are high. (extension.umn.edu, ohioline.osu.edu)
• Cautions: Barley can host Pratylenchus penetrans (root‑lesion nematode) and may serve as a “green bridge” for seedling diseases if left too long before a susceptible crop; terminate earlier (3–4 weeks pre‑plant) when pest transfer risk or dry springs are concerns. Avoid planting barley immediately after wheat to limit shared disease issues. (nrcs.usda.gov, covercrops.ces.ncsu.edu, sare.org)
• Water Requirements and Drought Tolerance: Barley uses moisture efficiently, is more drought‑tolerant than oats, and performs well on light, droughty soils; however, it does poorly in waterlogged conditions. In dry springs, consider earlier termination (about two weeks ahead of planting) to conserve seed‑zone moisture. (sarep.ucdavis.edu, sare.org, ipcm.wisc.edu)

Notes for Nitrogen Planning

• Barley is a scavenger, not a fixer. The amount of N held for the next crop depends on biomass and tissue N. For example, with typical Midwest biomass of 2,000–5,000 lb/ac and barley tissue N ≈1.2%, aboveground N held is roughly 24–60 lb N/ac (calculation based on published biomass and tissue-N values). Managers should account for slower N release as C:N rises with maturity; earlier termination speeds N cycling. (nrcs.usda.gov, sarep.ucdavis.edu)

Practical Tips

• Use higher seeding rates when broadcasting, on slopes, or for grazing. Calibrate seeders and, if broadcasting, lightly incorporate or press seed for better contact. (ohioline.osu.edu)
• Select regionally adapted winter or spring barley types; barley is less winter‑hardy than rye or wheat but matures earlier. (sarep.ucdavis.edu)
• To maximize weed suppression and erosion control, allow adequate spring growth before termination, balancing biomass targets against soil moisture and planting logistics. (covercrops.ces.ncsu.edu)

This guidance draws on USDA‑NRCS materials, SARE, and land‑grant university extension, emphasizing recent (2023–2025) factsheets where available.