R. Aaron Saeugling
Iowa State University Extension and Outreach
The dry conditions in parts of the state in 2022 put extra stress on pastures. Consequently, some pastures may have been grazed shorter than cattlemen would have liked. Additionally, nitrogen prices continue to rise as well as all costs associated with pasture management. As we head into the 2023 growing season, here are some considerations to help improve over-grazed and thin pastures, boost forage production, and help to manage pasture management costs.
For pasture stands that are on the thinner side, frost seeding or interseeding this spring can help to thicken stands up and be a longer-term solution to increase productivity. Now, not every pasture is ready for frost seeding or interseeding as its important to consider things like previous herbicide use, soil fertility and soil pH. Taking the time to properly plan and prepare will help with the success, and this ICM Blog “Still Time to Start Prepping for Pasture Renovations in 2021” addresses in more detail what should be done prior to any frost seeding or interseeding.
Early March can be a great time for frost seeding, whereas if you are planning on interseeding, that is typically done sometime between mid-March and early May. Read more on frost seeding and interseeding in the ICM Blog “Frost Seeding and Interseeding Considerations for Pastures This Spring.”
Frost seeding or interseeding with a legume can not only help to thicken up a pasture stand, but can also help lessen the amount of nitrogen that needs to be applied to the pasture. Nitrogen fixing legumes should include alfalfa, birdsfoot trefoil, and clover species. Keep in mind with legumes in a pasture, a soil pH above six is best and for alfalfa a soil pH of 6.9.
When it comes to seeding, it is important to consider seed placement and a drill is the preferred method for most legumes to provide good seed to soil contact. If broadcasting, try rolling or frost seed prior to a snow event to help the seed stick to the soil surface. After frost seeding or interseeding, monitor spring green up and do not allow competitive grass species to grow over 4 inches and shade out legumes as the legumes are getting established. Once the legumes catch up in size to the grass, then we can allow more grazing. After last season this year may be a good time to consider interseeding legumes on those overgrazed fall pastures this spring.
Additional resources on the ISU Extension Store:
- Interseeding and No-Till Pasture Renovation: https://store.extension.iastate.edu/product/4420
- Improving Pasture by Frost Seeding: https://store.extension.iastate.edu/product/4158
- Selecting Forage Species: https://store.extension.iastate.edu/product/5367
- Fertilizing Pasture: https://store.extension.iastate.edu/product/4175
- Steps to Establish and Maintain Legume-Grass Pastures: https://store.extension.iastate.edu/product/4332
- Pasture Management Guide for Livestock Producers: https://store.extension.iastate.edu/product/5256