Cereal Cover Crops: Seed Quality Troubles Impact Seeding Rates

Reported low cereal cover crop germination rates raise questions about seeding rates. University of Maryland Extension expert responds.

Published on: Sep 6, 2013

Low seed germination of barley, rye and wheat is an issue this fall, reports Bob Kratochvil, University of Maryland Extension agronomist. It's the result of sporadic Fusarium outbreaks in some areas, plus some pre-harvest sprouting caused by the rainy harvest season.

While Maryland's Cover Crop Program is the most successful water quality improvement initiative in the Chesapeake Bay region, the program's recommended cereal seeding rates can be problematic due to the low seed germination rates. "Many are asking," says Kratochvil, "How do I attain an acceptable stand when the germination of my seed lot is below the standard of 80%?" 

COVER YOUR COVER CROP SEED CONCERNS: Fusarium seed quality issues may require seeding rate adjustments for barley, rye and wheat.
COVER YOUR COVER CROP SEED CONCERNS: Fusarium seed quality issues may require seeding rate adjustments for barley, rye and wheat.

To start with, the recommended (and Maryland mandated) seeding rates for cover crop seeds with normal germination rates are: rye (112 pounds or 2 bushels per acre); wheat (120 pounds or 2 bushels per acre) and barley (120 pounds or 2½ bushels per acre). For commodity harvest production purposes, Kratochvil advises using a seeds-per-square-foot approach. It compensates for seed lot size variations – which can be substantial.

The recommendations are . . .
The following seeding rate recommendations require that cereal cover crops be planted using a tillage practice that incorporates the seed into the soil, i.e. planting with a grain drill or broadcasting seed followed by incorporation with either a vertical tillage implement or a disk:

Rye: Plant for 30 to 35 viable (adjusted for seed lot germination) seeds per square foot. Example: A rye seed lot with 85% germination would require a 35 to 41 seed planting rate. But a rye seed lot with 75% germination would require 40 to 47 seeds.

Wheat: Plant for 20 to 25 viable seeds per square foot. Example: A wheat seed lot with 90% germination would require 22 to 28 seeds. But a seed lot with 70% germination would require 29 to 36 seeds.

Barley: Plant for 24 to 30 viable seeds per square foot.  Example: A barley seed lot with 90% germination would require 27 to 33 seeds. But a barley seed lot with 75% germination would require 32 to 40 seeds.