Spring pasture tip: Hold up on that fertilizer
You'll do your pastures and cows a favor this spring if you leave the fertilizer spreader in the shed, and pull out the drill or seeder.
It's not that your pastures don't need fertilizer. It's just that this is the wrong time of year to put it there. It's counter-productive to what you most want out of your pastures -- a lush mix of grasses and legumes that will provide good grazing during the cool and wet spring, as well as the hot and dry summer.
That's what Rob Kallenbach, a forage specialist at the University of Missouri, told farmers and ranchers at the Cornbelt Cow-Calf Conference last Saturday at Vermeer headquarters in Pella, Iowa. Some farmers have the logic that you apply fertilizer to crops as they start the growing season, in the spring. While that works fine for crops like corn or wheat, it doesn't work for pastures, where you are usually trying to get multiple crops to grow, Kallenbach said. When it comes to pasture management in the spring, "I'd rather put my money into clover seed," he said. Here's why.
Take a typical Iowa-Missouri improved pasture that is roughly 70% tall fescue (a cool-season grass) and 30% red clover (a legume). The fescue does most of it's growing early in cool weather, then it pretty much stops growing in the heat of summer. It responds well to nitrogen fertilizer, but if you put the fertilizer on in the spring, you encourage additional lush fescue growth at a time that it is already growing rapidly anyway. And that growth crowds out clover or other legumes.
Rather, Kallenbach suggested that you use the spring as a good time to interseed or frost seed more clover. That helps keep the quality of the pasture forage mix high, and the clover adds some nitrogen to the soil. The clover plants are established by summer and can help maintain pasture quality through a hot spell.
Then, Kallenbach said, "I'd put the fertilizer on in the fall -- maybe starting in mid-August or sometime after that. If you get some fall rains, it will give your fescue a nice boost and help stretch your pastures farther," he said. "Fall fertilizer doesn't seem to hurt clover (or other legumes) stands as much. At that time, the grasses and legumes are growing together and not crowding each other so much."
Most pastures can well use 50-100 pounds of nitrogen an acre in the fall application, Kallenbach said.
Here are some other pasture management tips he offered cattle producers at the meeting:
Prepare a "pasture budget" going into the grazing season. You can do this by knowing your mix of forages, then estimating the production you expect each month of the grazing season. That can help you see how a change in the forage mix might better sustain production through the cool, then warm, then back to cool seasons. Put that chart next to the forage needs of the grazing livestock, and you can start to map out a way to stretch your grazing system so you will feed less hay or other purchased feeds. Kallenbach said that grazing is the cheapest way to feed cattle. In relative feed cost terms, hay costs about twice as much as pasture, silage and grains cost about three times as much, and dehydrated forages cost four times as much as pasture-based feed.