Cover Crop or Volunteer Crop?

Please take a look at the photo below and guess whether this is a well-established cover crop or just a thick, lush crop of a volunteer grain. The field was tilled once in late August, early September. The picture was taken on November 6th near Crookston. 

Photo 1 - Cover Crop or Volunteer Crop?

You are today's winner if you guessed a lush volunteer crop of spring wheat.  The headland immediately at the field entrance is thinner and anemic, as is the edge of the ditch.  Otherwise, this volunteer spring wheat crop checks every single box for what you would want a cereal cover crop to look like in late fall.

And that is the point of this blog - this meets all the criteria of how a cover crop should look in late fall, other than it was not sown by an approved seeding operation, nor does it contain a companion species. You should know that both mechanical and pneumatic fertilizer spreaders, in combination with tillage, can qualify as approved seeding operations. It is not that far of a stretch, in that case, to consider a properly set straw spreader (one which covers the width of the header) on a combine as an approved seeding operation. 

The only question that remains is whether the non-cereal companion species could/would add ecosystem services not provided by the cereal cover crop or help you attain specific goals.

A caveat of this type of volunteer spring wheat as a 'cover crop' is that, because of its early and very successful establishment, it is the perfect green bridge for some potentially serious pest and disease problems in next year's spring wheat in close proximity. 

This will only become a concern if some or all of the spring wheat overwinters.  The likelihood that any of it will survive the winter depends on the amount of snow cover this winter and whether the spring variety in question carries a vernalization gene inherited from a winter wheat at some point in the family tree. 

Should that be a reason to abandon the idea that volunteer spring cereal can serve as a cover crop? Absolutely not.  Terminating any surviving volunteer in very early spring with a combination of a burndown herbicide and tillage all but eliminates the risk that the green bridge closes.