After the last several years of dry conditions, some pastures may benefit from a renovation in 2024. Proper planning and preparation are needed to successfully improve pastures with either a late winter frost seeding or no-till renovation with interseeding next spring. Below are some good reminders on what you should be doing now to prepare for pasture renovations in 2024.
Address soil fertility needs. To improve the success of frost seeding or interseeding, adequate soil fertility is important. The only way to know what the soil fertility levels are in your pasture is by taking soil samples for testing. Preferably, take soil samples yet this fall to determine lime, phosphorus, and potassium needs. More information on soil sampling and testing is available here.
- 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 should be applied a year before seeding. Liming recommendations can be found in Table 16 in the ISU publication PM1688: A General Guide for Crop Nutrients and Limestone Recommendations in Iowa. Note that if placing lime on the soil surface with no incorporation, follow the 2-to-3-inch lime recommendations in Table 16.
- Adequate phosphorus and potassium are important to improve pasture 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 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 thistles or other broadleaf weeds are problematic, control them before adding a legume to a pasture or hay stand. Fall can be a good time to control these problematic weeds.
With it being early October, we have a good window yet to do fall herbicide applications in pastures. Applications should be made when the sun is shining and daytime temperatures are above 50-55 degrees Fahrenheit. Fall herbicide applications can still be effective even after a frost event (or too). However, before spraying check the weeds present to make sure they still look healthy enough to spray.
Also, always read and follow herbicide labels and 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. This also helps improve seed-to-soil contact when frost seeding or interseeding next year.