Cow-Calf Commentary for Iowa Cattleman Magazine
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By Erika Lundy, extension beef specialist, and Beth Reynolds, extension program specialist
Early Spring Pasture Management Tips
After a long winter, you’re ready for your cows to be out on pasture, but are your pastures ready for your cows? Here are some considerations to help make the most of 2020 pasture yields.
Regardless of your management style, making a grazing plan prior to pasture turnout is a good idea. For intensive rotational grazers, this might include a schedule of how often you plan to rotate, the order of pasture or paddock rotation, and which paddocks might need extra rest this year after getting torn up in last year’s mud. For grazers that rotate between 2-5 paddocks throughout the grazing season, this might include the order you intend to rotate through the pastures, and identifying what time the cows need to be in the paddock with working facilities so your herd health plan can easily be followed. Even continuous grazers benefit from a grazing plan that includes back-up feed resources in case of a drought or feed shortage. Timing of fertilizer or herbicide application, notes on paddocks that need more rest after being grazed hard or previously interseeded areas in a pasture are also beneficial to note in a grazing plan.
Frost seeding or interseeding are good options to introduce some new species of grasses or legumes to thicken thin stands or cover bare ground. Frost seeding is the best option for introducing legumes and requires good seed to soil contact. The idea behind frost seeding is that the freeze-thaw cycles during this time of year will help provide the desired shallow seedbed. Introducing additional grass seed or a combination of grass and legume seeds is more successful with interseeding and typically yields a more consistent stand. Maintaining shallow seed depth and reducing competition from existing forage is important when drilling new forages.
To ensure pastures can optimize productivity year after year, understanding soil fertility is important for pastures that are both harvested for hay and grazed. Routinely soil testing pastures every four to five years, can verify fertilizer input decisions and improve overall forage productivity. Monitoring soil pH is also beneficial if you are targeting legume-mixed pastures since legumes prefer a slightly higher soil pH compared to grass species. If interseeding or frost seeding into existing stands, fall application of nitrogen is recommended to avoid competition of other grasses. If fertilized in the spring, unimproved fescue responds to nitrogen really well and will choke out other grass species.
While perennial weed control in pastures is typically best suited for herbicide application in the fall, spring is an effective time to scout and control some winter biennial and annual weeds such as musk thistle, Queen Anne’s lace, wild carrot, or marestail. These weeds should be treated before they bolt or send up a flower stalk. With herbicides, always make sure to read and follow label instructions and pay special attention to pre-harvest intervals or any grazing restrictions. Maintaining a vigorous forage stand is critical when it comes to weed management.
As you get ready for pasture turnout, keep in mind that forage mass above ground is a direct indication of root mass below ground. Forage height should be at least 4 - 6 inches on average before grazing initiation. Grazing too early can result in root structure damage, further delaying plant regrowth and hinder overall forage yield throughout the summer. While it might not be possible to keep cows off of all pastures until the forage is ready, limiting access and providing supplemental feed can be beneficial to lessen the overall forage yield loss. Providing rest for the segment of pasture grazed early is important to allow regrowth before grazing again.
After turnout, consider utilizing a temporary fence around the winter feeding area in order to give the forage time to establish roots and a healthy forage stand before giving cows access to it again.
Don’t forget the minerals and vitamins! While minerals make up a very small portion of a cow’s diet, minerals play an important role in health, growth, reproductive performance and are critical during the time between calving and breeding. Lush, green forages early in spring are high in potassium which limits absorption of magnesium. Therefore, providing high magnesium mineral a few weeks prior to grass turnout through a few weeks post turnout has proven to be beneficial in preventing grass tetany.
Finally, write down what you actually do throughout the grazing season! Keeping basic records of your decisions gives you the power to evaluate what worked, what didn’t, and what needs more attention next year, ultimately improving your operation’s efficiency and bottom line.