Many pastures have lots of soil moisture from spring rains. Fertilizer might help you take advantage of that moisture, says Bruce Anderson,University of Nebraska forage specialist.
Grass growth is stimulated by nitrogen fertilizer just like other crops. One key to profitable fertilizing of pastures, though, is to time fertilization to stimulate grass growth when you need it. "We often fertilize cool-season grass pastures in early April to get a good boost in early growth," Anderson says. "By June or July, though, these pastures run out of both moisture and fertilizer. Add in hot temperatures and their growth nearly stops."
This spring many pastures received abundant rain. Pastures should be able to continue to grow longer into summer if soil fertility is adequate. To take advantage of this extra soil moisture, fertilize cool-season pastures with 30 to 60 pounds of nitrogen per acre between now and Memorial Day to gain extra summer forage.
"To make May fertilizing work best, I have found that it helps to graze pastures moderately before adding nitrogen fertilizer," Anderson says. "This seems to encourage more thickening of the grass stand and slightly reduces the number of seed stalks produced. Don't graze too short, though, or plants will be stunned and regrow more slowly."
He adds, "Some producers ask me if it is smart to fertilize again if they applied nitrogen earlier this spring? Normally I say no, especially with nitrogen so expensive. But if you applied just a light amount earlier and already have grazed off most of the grass, a second application might be beneficial, similar to the multiple nitrogen applications used on irrigated pastures."
Another pasture tip is to control ragweeds, according to Anderson.
Ragweed growth exploded in some pastures during recent years. Timely spring rains encouraged germination and seedling growth. Sunny dry falls helped seed develop. And heavy grazing or drought weakened competition, he says.
Both common ragweed, which is an annual, and western ragweed, which is a perennial, can be held in check using similar methods. However, common ragweed is controlled more easily with grazing management or herbicides than western ragweed.
Research and observations both show that ragweed problems are worst in pastures that fail to maintain competition from a full leaf canopy of grass during late May through late June.
"If you had ragweed problems the past couple of years, tiny ragweed plants or seedlings will develop underneath your grass during the next few weeks," he says. "Heavy grazing or haying during this time opens up the grass sward, letting these seedlings and small plants grow rapidly."
Management that develops and maintains a dense leaf canopy at this time helps reduce problems with ragweed. This includes increasing grass growth with fertilizer and thickening stands by seeding, but most important of all is to avoid grazing heavily in areas with ragweed problems.If you do graze heavily or cut hay, spraying herbicides like 2,4-D or Grazon or Milestone or Forefront after grazing or cutting gives good control of ragweed seedlings and small plants, Anderson adds.