Published Apr 24, 2014

Thinking about letting a winter cereal cover crop go to grain?

By Stefan Gailans
Winter rye 2

Winter cereal rye cover crop after “green-up” in the spring.

We are considering allowing some rye to mature and harvest for cover crop seed this fall. How do I know if the stand is adequate? How much N should I apply? 

We get this question a lot at the Practical Farmers of Iowa office. So many of our members now use cover crops in their production systems and many of them are now raising their own cover crop seed (to use themselves or sell to their neighbors).

PFI2021 CC CostShare Ad 1024x224pxIf you seeded a winter cereal grain (rye, wheat, or triticale) last fall as a cover crop and are considering letting the crop reach maturity to harvest for grain and straw, here are a few things to keep in mind:

  • STAND: 30 seedlings per acre coming out of winter is considered a good stand for a cereal grain. This should allow for sufficient tillering resulting in 2-3 seed heads per plant.
  • NITROGEN: 30-60 lb N per acre is probably enough in Iowa. Nitrogen can be topdressed over the cereal grain just after crop “green-up” in the spring as a granular fertilizer (urea, AMS, etc.). Applying N at this time will encourage tillering. Waiting until the crop reaches jointing stage to apply N fertilizer will not likely translate into yield improvement. It should be noted that applying too much N can result in excessive vegetative growth in cereal grains and lead to lodging and subsequent yield loss.
arapahoe 2

Winter cereal rye just prior to jointing stage (stem elongation).

Below are a couple of good references for anyone considering growing winter cereal grains.

Gibson, L., J. Singer, S. Barnhart, and B. Blaser. 2008. Intercropping winter cereal grains and red clover. PM 2025. Available online at (verified 24 Apr. 2014). Iowa State Univ. Extension, Ames.

Oelke, E., E. Oplinger, H. Bahri, B. Durgan, D. Putnam, J. Doll, and K. Kelling. 1990. Rye. Available online at (verified 24 Apr. 2014). Alternative crops manual. Univ. Wisconsin Cooperative Extension, Madison.

Additionally, here are a couple of research reports from our Cooperators’ Program addressing the production of winter cereal grains. Look for more research reports regarding winter cereal grains to come in the future from the Cooperators’ Program that address N fertility for winter cereal rye and the effect on corn yields of including a cereal grain + legume in a crop rotation.

Interseeding winter rye with red clover

Cover crops do double duty: cover and grain

2013-07-22 11.59.18

Mature winter wheat just before harvest.