Fertilizing Cool Season Grasses in May
Do you remember my comments about six weeks ago about fertilizing cool-season grass pastures? I mentioned that many pastures grow faster than cattle can graze in the spring so why fertilize all the pastures and end up wasting lots of extra grass. Instead, I suggested that you fertilize only some pastures early. Then wait until mid-May to fertilize the other pastures if soil moisture is good at that time. That way, the later fertilized pastures will be stimulated to grow better into early summer when you might need more of the grass. If you followed my advice, now is the time to take advantage of extra soil moisture. Fertilize cool-season pastures with thirty to sixty pounds of nitrogen per acre between now and the end of the month to gain extra summer forage.
To make May fertilizing work best, I have found that it helps to graze the pastures moderately before adding the nitrogen fertilizer. 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. Would it be smart to fertilize again if you 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 N applications used on irrigated pastures.
So, if you can use extra grass, fertilize now to take advantage of extra moisture.
[May 10th, 2007]
Dr. Bruce Anderson, Professor of Agronomy
Agronomy & Horticulture, University of Nebraska - Lincoln, Lincoln, NE