Fertilizing Pastures

March 2012

After adding a hundred, sixty, or even just forty pounds of nitrogen per acre to your pastures in past years, did your grass grow really nice in April and May? Then did it get stemmy in June with cows trampling and laying on it more than eating it? And by August was most of the grass brown or dead, much of it matted down, with the only green material so short that cows could barely get any of it?

If this describes your pastures, do something a little different this year. For starters, don't fertilize all your pasture right away. You're stimulating more spring growth than your cows can eat, so only fertilize half or three-quarters of your pasture now. Be sure, though, that the unfertilized area is fenced off from the rest of the pasture.

Now, go ahead and have your cows graze pretty much like you normally do but be sure to graze the unfertilized area so you finish with it sometime in mid-May. Then check the weather and soil moisture. If you think there will be enough moisture for some good regrowth, then fertilize this previously unfertilized area. Let it regrow for six weeks or longer and you should have some really good grazing available for July or August.

What if it's dry in mid-May with poor prospects for regrowth? In that case, save your money and don't apply any more fertilizer. You still will have produced about as much pasture growth as if you had fertilized everything to begin with, but without spending as much.

If your pastures are overgrown in spring and run out in summer every year, change fertilizer timing. You'll get more grass when you want it or maybe save some money.

Dr. Bruce Anderson, Professor of Agronomy
Extension Forage Specialist
Agronomy & Horticulture, University of Nebraska–Lincoln, Lincoln, NE