Cover crops are planted in addition to a cash crop in order to gain environmental and economic benefits.
In a typical corn-soybean rotation, there are only living roots in the ground 4-5 months out of the year. Fall and Spring rains often arrive in Iowa when there are no living roots on agricultural fields, leading to Nitrate-N being washed away. Cover crops provide living roots during this time of year, which absorb Nitrate-N and prevent it from being lost.
According to Iowa’s Nutrient Reduction Strategy cereal rye and oat cover crops, when included in a corn-soybean rotation, have the potential to reduce Nitrate-N loss by 31% and 28%, respectively. A cereal rye cover crop has the potential to decrease phosphorus loss by 29% according to the same report.
“I use cover crops for soil health, to reduce compaction, improve water infiltration, increase organic matter and biological activity. The increased soil health from my cover crops and strip tillage have reduced costs and increased yields on my farm, a net gain.”
Bob Lynch, Farmer, Humboldt County Iowa
Cover Crop Benefits:
- Decrease soil erosion
- Increase soil microbial activity (soil health)
- Decrease nutrient runoff and leaching
- Increase soil carbon
- Suppress weeds
- Improve soil structure (increased infiltration, decreased compaction, increased water holding capacity)
- Soil moisture management
- Habitat for beneficial insects, pollinators and wildlife
- Forage for farm animals
- Break disease cycles
- Estimated at $25-$30 per acre
- Compatible with existing federal and state cost-share programs so farmers can recoup some of their costs
- Sustainable Agriculture Research & Education (SARE): General benefits of Cover Crops and the different management systems which they can be incorporated into. Descriptions of different Cover Crop varieties, and how to select and manage them.
- Practical Farmers of Iowa (PFI): Links to many different Iowa-focused Cover Crops resources (including a list of businesses that can supply seeds and custom planting) and access to PFI’s on farm research trials.
- Natural Resources Conservation Service (NRCS): A general factsheet on Cover Crops in Iowa from the NRCS.
- Midwest Cover Crop Council: A one stop shop for all things Cover Crops.