Missouri Ruralist logo

Hold off on fertilizing forage until August for best fall growth.

Duane Dailey, Freelance

July 25, 2019

3 Min Read
beef cow and calf
GRAZE MORE: Summer pastures may need a boost to get cows and calves through the winter grazing months.

Tall fescue, Missouri's most-used pasture grass, provides fall and winter grazing with proper management. With a growing concern about lack of stored forage, grazing offers potential feed this year.

Fescue grows in two distinct seasons, spring and fall. Fall growth isn't as robust as in spring. With good management, though, fescue allows for grazing well into winter. An advantage of fall tall fescue growth is that it can stay standing and edible past frosts and even winter storms.

Grazing, especially management-intensive grazing, reduces the need for baling hay for winter feed. That cuts costs and labor.

MU forage specialist Craig Roberts says July is when thinking about managing fescue should begin. August brings time for action. Much of needed growth comes in September. With fall fescue growth, thinking before acting improves benefits.

When to add nitrogen

Fall grazing depends on Missouri weather. Lack of rain or early freeze changes growth dynamics. Roberts says unusual early rains this summer may have producers jumping the gun.

Fertilizer timing varies across the state. In mid-Missouri, the target application date is Aug. 15. In northern Missouri, earlier at Aug. 10 works. In the Ozarks, closer to Arkansas, delay until late August. Even if it looks like there'll never be another rain, Roberts urges applying nitrogen on the suggested dates.

Usually, farmers count on fall rains starting Sept. 1. Sometimes Gulf coast hurricanes change that date. Tropical storms bring extra rain to mid-America. That grows more grass.

A key part of increased production depends on a boost application of nitrogen fertilizer. That helps fall growth. “Don't add nitrogen now,” Roberts says. “Added fertility will just give you high-yielding foxtail or other annual warm-season weeds.”

The other yield booster is to graze down existing pasture before fall growth starts. That includes lowering annual grasses and legumes in the fescue. “Clear the deck for the fall growth,” Roberts says.

This isn't time to assume that if a little bit of fertilizer is good, then a lot must be better. Adding nitrogen to toxic tall fescue takes caution. Nitrogen does not only boost grass growth, but also increases fescue toxicosis.

Beware of toxins

Fescue toxins bring a host of bad side effects. In extreme cases, the ergovaline causes fescue foot, which kill cows. More subtle losses are in lower gains, less milk, heat stress and other ills.

Toxins are low in summer months but can rise in hot weather. Then cattle quit grazing and head to ponds or creeks to cool off. Early application of nitrogen in July increases toxins, detracting from fescue's advantages.

The cautions from forage specialists come in timing and limiting nitrogen spreading. “With toxicity, 50 pounds of N hits maximum limit,” Roberts says.

Consider new planting

Producers thinking ahead and killing their toxic K-31 fescue to seed nontoxic novel-endophyte fescue see great potential.

The new fescues take more fertility. “Go for 80 to 100 pounds of nitrogen per acre on novel endophyte,” Roberts says. “There's no threat of fescue foot and all of that.”

For maximum benefit from fall growth, rotational grazing extends stand usage. Methods used for management-intensive grazing (MiG) are taught at University of Missouri Grazing Schools.

Regional MU agronomists teach grazing management and can be contacted through local county MU Extension offices.

Dailey is a retired MU extension professor. He writes from his home in Columbia.


About the Author(s)

Subscribe to receive top agriculture news
Be informed daily with these free e-newsletters

You May Also Like