Start Planning Now for Pasture Renovations in 2020

Proper planning and preparation are needed to successfully improve pastures with either late winter frost seeding or no-till renovation with interseeding next spring. This ICM Blog post will discuss what you should be doing now to prepare for pasture renovations in 2020.

• Address soil fertility needs. To improve the success of frost seeding or interseeding, adequate soil fertility is important. To know what the soil fertility levels are, you need to take soil samples for testing. More information on soil sampling and testing can be found in the Recipe for Success blog.
  • From a pH perspective, a soil pH of 6.0 is recommended for grass, clovers, and birdsfoot trefoil and for alfalfa a soil pH of 6.9 is recommended. Ideally lime would be applied a year before seeding.
     
  • Adequate phosphorus and potassium are also important to improve establishment and production. Use soil test results to determine if phosphorus and potassium levels are adequate or if levels are low and it would be beneficial to apply some fertilizer to bring up those levels.
     
  • Do not apply early season nitrogen to frost seeded or interseeded areas in order to minimize early season growth and competition from weeds and already established plants in the area.
     
  • More information on fertilizing pastures can be found in the ISU publications: PM1688: A General Guide for Crop Nutrients and Limestone Recommendations in Iowa and PM869: Fertilizing Pasture.
     
• Control problematic weeds. If you struggle with thistles or other broadleaf weeds, be sure to get them under control before adding a legume to a pasture or hay stand. Fall can be a good time to control these problematic weeds. If you use a herbicide to control weeds, do double-check crop rotational intervals on the herbicide label before seeding. 
   
• Reduce current stand competition. Typically over-grazing or mowing a forage stand short is not recommended. However, when it comes to frost seeding or interseeding into an existing stand, it is advised to over-graze or mow the stand short this fall. This will weaken the current stand, but it will help the new seeding to compete with the current stand next spring. Additionally, this helps to get better seed-to-soil contact.

More information on frost seeding can be found in the Improving Pasture ISU Extension Store article, and more information on interseeding can be found in the Interseeding ISU Extension Store article.