Equipping farmers to build resilient farms and communities.
Sam Bennett of Galva, IA is a die-hard cover cropper, but last year the drought had him second guessing the time and money necessary for implementing cover crops. “We chickened out last fall,” Sam says, “after seeing neighbors’ cover crops [seeded in mid-August] that germinated, grew a bit, then died. We could have done it and still have had okay spring growth.”

Despite the dry conditions, Sam will aerially apply cereal rye at his typical rate of one bushel/acre around Labor Day. Below are some of his thoughts on the importance of cover crops during dry years. Sam emphasized that long-term cover cropping drastically increases the water-holding capacity of soils, which will help withstand drought in the future.

Nitrogen retention: “If you apply nitrogen at a rate expecting to get 250 bushel/acre corn, and yield closer to 150 bushel/acre, there is a lot of nitrogen left in the soil. The rye cover crop helps to keep nitrogen from leaching below the rootzone,” notes Sam. “We want to retain this N for future crops, and I think it is our responsibility to keep that nitrogen out of the water bodies.”

Addressing next year’s drought-stressed weeds: We may continue to have dry weather in upcoming years, and herbicide products are less effective on drought-stressed weeds that are not growing and metabolizing the product. Sam explains that even if he terminates the cover when it is small, he still sees some additional waterhemp control: important when lack of moisture inhibits herbicide efficacy.

Tips for seeding into dry conditions: Watch for herbicide carry-over interfering with cover crop establishment. Lack of soil moisture means that certain products are not metabolized as quickly as a normal year. To check to see if your herbicide program affects cover crop establishment, Sam suggests digging up an inch of soil, bringing it inside, and trial-seeding your intended cover crop species to see how it does before seeding a field.
Ready to invest in cover crops on your farm?

You could earn $1,600 or more to help offset the cost– fill out the application to see if you’re eligible.
Practical Farmers has released a new cover crop app designed to help farmers locate cover crop seed suppliers and service providers. The free app, Find Cover Crops, is available for download on the Apple App StoreGoogle Play Store and a desktop version is also available.

The app can help you access 44 cover crop seed dealers, seed cleaning and custom spraying services located across Iowa and surrounding states.
Chances of rain
Cover crop germination is contingent on adequate moisture. The graphs above show the historical probability of over one inch of rain within 24 hours during the defined windows. (Data includes precipitation records from 1989 to 2019; it was provided by Daryl Herzmann at ISU’s Mesonet.)
Aerially seeding cover crops can provide a jump-start on biomass production and can save you time later in the fall.

But for aerial seeding to be successful, you’ll need to evaluate the conditions of the crop you’re seeding into and the weather forecast.

Typically after a drought year we observe large “pulses” of nitrogen leaving fields and finding its way to waterbodies.

Research by Iowa State indicates that cover crops can scavenge and recycle this nitrogen. In a study out of Gilmore City, cover crops reduced tile nitrate concentration by 51 percent.
Hosted by: Craig Swartz & America's Conservation Ag Movement
August 11 | 6:30 - 11:30 a.m. CT | Emington, IL

Hosted by: Kelly Nelson and Iowa Learning Farm
August 11 | Noon CT | Online

Hosted by: Roger Wenning and CSSI
August 18 | 8:30 a.m. - 2:30 p.m. ET | Greensburg, IN

Hosted by: Ehsan Ghane and Iowa Learning Farm
August 18 | Noon CT | Online

Hosted by: Soil Health Nexus
August 18 | 2:00 p.m. CT | Online

Hosted by: Bobolink Prairie Farms, Wilcox Farms & Practical Farmers
August 21 | 2:30 - 4:30 p.m. CT | Correctionville, IA

Hosted by: Lee Tesdell, Polk County SWCD & Practical Farmers
August 23 | 10:00 - Noon CT | Slater, IA

Hosted by: Vermillion-Parke Soil Health Alliance
August 24 | 7:30 a.m. - 3:00 p.m. ET | Rosedale, IN

Hosted by: Joshua Hiemstra, Becky Wagner & Practical Farmers
August 24 | 1:30 - 2:15 p.m. CT | Online

Hosted by: John Burger & Practical Farmers
August 28 | 9:30 - 11:30 a.m. CT | Udell, IA

Hosted by: Mark Licht and Iowa Learning Farm
August 25 | Noon CT | Online
Want to host a cover crop meet up? Contact Sarah if interested sarah@practicalfarmers.org
Are you planning or hosting a cover crop event? Send the details to rebecca@practicalfarmers.org, and we’ll include it in our next newsletter.
Send us your cover crop poll ideas! We want to know what YOU want to know. Reply to this email with your ideas for the next poll.
Have you had issues with carryover herbicide interfering with cover crop establishment?
Previous poll results:
Have you purchased cover crop seed?
  • No, I have not bought my cover crop seed yet - 47.6%
  • Yes, I have cover crop seed for all of my fields - 28.6%
  • Yes, but I only have cover crop seed for some of my fields - 14.3%
  • No, I will not be planting a cover crop this year - 9.5%
Sarah Carlson
Strategic Initiatives Director
(515) 232-5661
Chris Wilbeck
Independent Contractor
(515) 232-5661
Rebecca Clay
Strategic Initiatives Agronomy Coordinator
(515) 232-5661