Is it Time to Graze Your Pastures?
As spring rolls in, our cool-season pastures start showing signs of life and look more enticing than the muddy feeding areas. But before we let our livestock loose, it's crucial to assess whether pastures are truly ready. While the temptation might be strong, premature grazing can spell trouble, especially for pastures that have already weathered tough times, leading to slow green-up in areas in areas across Iowa. Fertilizer applications can be beneficial in giving these pastures a boost. For more information on fertilizer application rates ICM blog post on forage fertilization and the PM 1688 “A General Guide for Crop Nutrient and Limestone Recommendations in Iowa”
Timing is Everything
Timing matters. We don't want to rush and stress our struggling pastures further, but waiting too long can mean missing out on prime grazing opportunities. For those practicing rotational grazing, the timeline shifts a bit. Continuous stocking systems should hold off until pastures reach 8-10 inches in height, while rotational systems can consider releasing animals at about 6 inches. Rotational grazing aims to avoid overgrazing by removing animals before overgrazing and giving the plants a rest period.
Quick Rotations for Spring
Spring rotations must be swift, grazing down to 3-4 inches, then moving. Stubble height can vary depending on the plant species, such as Kentucky bluegrass, and many of our legumes can be grazed lower to ~2 inches, while orchardgrass and timothy need a higher stubble height of 3-4 inches. In a mixture, grazing to a higher height can help maintain species diversity within the stand. Quick rotations help us keep pace with the rapid growth of spring, promoting tillering and trying to remain in vegetative growth.
Managing Surplus Forage
Spring often brings more forage than our animals can consume during the spring flush (figure 1). If you have the capacity, consider adding more cattle, such as stockers or developing heifers, to utilize this excess forage. Alternatively, setting aside a paddock for hay or baleage can make good use of surplus forage. You can also leave some areas untouched to stockpile for the summer months, though keep in mind this material will mature, and the quality will decrease, so utilize it with animals that have low nutritional requirements. However, this is not recommended with toxic-endophyte tall fescue though, as the endophyte concentration increases in the seed head.
