What the research measured
The Iowa fact sheet lists 1,000 to 4,000 lb of dry matter per acre per year for oats, and SARE lists 2,000 to 4,000 lb from late-summer or early-fall seedings. In Minnesota trials reported in 2025 an oat–radish mix measured from 425 to 540 lb/ac at Lamberton to 2,200–3,000 lb/ac at Waseca, and a 2018 Michigan variety test measured 1.07 ton/ac of fall biomass for the Jerry oat check. Penn State measured 19 lb N/ac (range 12–26) in oat biomass at termination.
A joint USDA-NRCS and Iowa State fact sheet, SARE’s species chapter, a three-site Minnesota Extension seeding-rate trial, a one-site Michigan State variety test and Penn State’s cover-crop biomass-N table. No peer-reviewed multi-site study of oats alone before corn or soybean could be opened at checking time, so there is no following-crop yield chart.5 independent sources.What it is. A cool-season annual grass drilled or broadcast in late summer after a small grain, silage or early soybean harvest, or in early spring ahead of a later crop. In the upper Midwest the fall stand dies over winter, so the following crop is planted into dead residue with no spring termination pass.
Study conditions and limitations
- Planting date drives the stand: SARE reports oats planted August 25 had 39% fewer weed plants in spring than control plots, while oats planted two weeks later had 10% fewer; Iowa’s fall window is mid-August to mid-September and the Minnesota trials prioritized seeding before mid-September.
- Winterkill is regional: SARE lists winterkill in Hardiness Zone 6 and colder and much of Zone 7, and the Iowa sheet gives a 25°F cold-tolerance temperature. Where oats overwinter, budget for a spring termination.
- Fall uptake is not a spring credit: SARE says late-summer plantings can absorb as much as 77 lb N/ac in eight to ten weeks, but Penn State measured 19 lb N/ac (12–26) in oat biomass at termination and the Iowa sheet lists a 33:1 carbon-to-nitrogen ratio.
- Seeding rates differ widely by source: 60 lb/ac PLS drilled, 66 broadcast and 75 aerial in Iowa; 2 to 3 bushels drilled or 3 to 4 broadcast in SARE (a bushel is 32 lb); 32 lb/ac in the Michigan test; 10 to 60 lb/ac in the Minnesota trial.
- Most Midwest trial numbers are for mixes, not oats alone: the Minnesota figures are an oat–radish mix, and in Michigan the Pratext black oat (a different species) made 2.59 ton/ac against 1.07 for Jerry oats.
- SARE advises waiting two to three weeks after killing oats before planting the next crop, and the Iowa sheet cautions that oats overseeded into soybeans can grow enough to interfere with harvest.
Read the sources · 5
- Oats cover crop fact sheet for Iowa (CROP 3243) ↗
Dry matter of 1,000 to 4,000 lb/ac per year depending on planting and termination dates and precipitation; oats usually winter kill in Iowa and need no spring termination. Drill 60 lb/ac PLS from mid-August to mid-September or early to late April; C:N ratio 33:1; grazing quality rated very good.
- Oats (Avena sativa), in Managing Cover Crops Profitably (3rd edition) ↗
Expect 2,000 to 4,000 lb of dry matter per acre from late-summer or early-fall seeded oats and up to 8,000 lb from spring stands; late-summer plantings can absorb as much as 77 lb N/ac in eight to ten weeks. Oats winterkill in Zone 6 and colder and much of Zone 7.
- Cover crops 2025: What should you plant? ↗
Oats seeded at 10 to 60 lb/ac with radish at 1 to 6 lb/ac, planted before mid-September, produced more than 850 lb/ac of biomass at St. Paul, 2,200 to 3,000 lb/ac at Waseca and 425 to 540 lb/ac at Lamberton.
- 2019 MSU Cover Crop Variety Test Report (Forage Factsheet 20-01) ↗
Drilled 8/15/18 at 32 lb/ac at Hickory Corners, Michigan, the Jerry oat check made 1.07 ton DM/ac of fall biomass and Pratext black oats 2.59; all oats winterkilled but left 0.55 to 1.32 ton/ac of dead residue cover in spring.
- Soil Organic Matter and Cover Crop-based Nitrogen Recommendations for Corn ↗
In Pennsylvania measurements at maximum spring growth before termination, the oats (spring) row averaged 19 lb N/ac in biomass with a range of 12 to 26, against 32 to 54 for cereal rye or wheat by growth stage.
Before you buy, ask
- What seeding rate, date, and termination timing did the cited studies use?
- How does termination timing before my cash crop change the nitrogen and moisture picture?
- Which species or mixture fits my rotation window and equipment?
Record
- Sources checked
- October 12, 2026. Every figure shown is printed on the linked page; unit conversions are noted on the chart.
- Company response
- None yet. Makers and suppliers of this product can send corrections, additional trials, or a statement; it is published here, labelled, and never edits the research summary. Send a correction →