Equipping farmers to build resilient farms and communities.
Dean Sponheim farms and custom plants cover crops with Sponheim Sales and Services near Nora Springs in north central Iowa. He began applying cover crops in 2012 and has expanded the business to aerial seed over 17,000 acres and drill over 6,500 acres in 2018.
The wet spring is causing later harvest dates for some and has farmers thinking about how they’ll get their cover crops planted early enough this fall to get well-established, but not so early that they’re shaded out by the cash crop.

This week, we chatted with Dean about timing for when to “pull the trigger” when flying on cover crops.
Timing for flying into corn: Dean recommends flying cover crops into corn at senescence, or leaf drop, to ensure that the cover crop receives plenty of light. To get an idea of when a crop might begin leaf drop, you can calculate your crop’s predicted black layer date.

Timing for flying into soybeans: Dean has found that flying on the cover crop when leaves are turning yellow, but have not yet dropped is best for beans. If the cover crop is flown into the beans after leaf drop, the cover crop seed might germinate, but the cover crop roots might not penetrate the soybean leaves, preventing establishment.

Timing around forecasts: Since aerially-applied seed sits on the soil surface as opposed to getting drilled into moist soil, it is important that rain is forecasted within the next week or so after flying on cover crops.

However, Dean recommends not to get caught up in the details of picking the perfect time to plant cover crops. He recommends just getting the cover crop planted, because it is difficult to find perfect conditions.
Remember NRCS cost-share dates: Dean reminded us that if participating in an NRCS EQIP cost share program for cover crops, you must pay attention to the cut-off dates for planting.

We pulled this graphic from the NRCS “Iowa Agronomy Technical Note 38: Cover Crop Management,” published in August 2018. If participating only in the PFI-administrated private cover crop cost share, seeding dates and rates are more flexible.

Advice for beginning cover croppers: Keep it simple. For first-timers, cereal rye or oats are easier to work with than mixes.
How has the wet spring affected your harvest and cover crop plans?
No difference from previous years
We're harvesting and planting cover crops 1-2 weeks later than normal
We're harvesting and planting cover crops 3+ weeks later than normal
Previous poll results:
What will be the dominant way you establish cover crops this fall?
  • Drill - 49%
  • Aerial Application - 27%
  • Overseed into a standing crop with a ground rig - 10%
  • Broadcast post-harvest, with incorporation (VT, etc.) - 8%
  • Broadcast post-harvest, no incorporation - 6%
Where are you sourcing your cover crop seed? Who is custom planting for you this fall? Find out what is available near you through our online cover crop directory.

To get your business listed in the cover crop business directory, e-mail jason@practicalfarmers.org with your business name, services offered, website or Facebook page, location and phone number.
Cover crop planting season is coming for the northern Cornbelt! Many farmers are gearing up to aerial seed cover crops but how can we make sure we have green fields in the fall during harvest?
Curious about aerial seeding your cover crop?

Take a look at what goes on behind the scenes when aerially seeding fall cover crops. This blog features photos collected from Roger & Mary Knutson’s farm near Hubbard from a few years ago.
Explore strategies for effective aerial seeding of cover crops – pilots and a cover crop consultant discuss what works for them, including seed selection, equipment needs, and timing of application.

This Farminar is geared towards pilots but there is something for anyone interested in aerial seeding of cover crops.
Enrolled in cost-share? Don't forget to attend a cover crop learning event
Remember that if you’re enrolled in the PFI-administered private cover crop cost share program, you are required to attend a cover crop learning event this calendar year. See upcoming events below.
Host a cover crop meet-up!
Want to host a casual gathering to talk cover crops? Sarah Carlson will bring the pizza and drinks. You bring the neighbors to talk cover crops. Contact Sarah if interested sarah@practicalfarmers.org.
Hosts: Ted & Linda Krauskopf
August 26 & 27 | 9 a.m - 4 p.m. | Highland, IL

Hosts: Jon Dana and Dr. Allen Williams
August 28 | 8:30 a.m - 4 p.m. | Richmond, MO
Hosted by: Iowa Farmers Union
August 28 | 4-6 p.m. | Prairie City, IA

Hosted by: Iowa Learning Farms
September 11 | 5:30-7:30 p.m. | Gilmore City, IA
Are you planning or hosting a cover crop field day? Send the details to rebecca@practicalfarmers.org, and we’ll include it in our next newsletter!
Alisha Bower
Strategic Initiatives Manager
(515) 232-5661
Sarah Carlson
Strategic Initiatives Director
(515) 232-5661
Chris Wilbeck
Independent Contractor
(515) 232-5661
Rebecca Clay
Strategic Initiatives Assistant
(515) 232-5661