Nebraska research shows that you get about 1 pound of additional calf or yearling gain for every pound of nitrogen fertilizer applied, says Bruce Anderson, UNL forage specialist. "However, this fertilization rule-of-thumb assumes that the amount applied is within our general recommendations, which are based on the potential amount of extra grass growth expected. This is affected mostly by moisture," he says.

These recommendations can be found in NebGuide1977, Fertilizing Grass Pastures and Hayland, available at county Extension offices. It also assumes that your grazing management will efficiently harvest this extra growth.

If you fertilize pasture in spring and then let animals graze continuously on one pasture throughout the season, much of the extra growth is wasted. "They trample, manure and foul, bed down on, and simply refuse to eat much of the grass. Eventually, less than one-third of the extra grass ends up inside your livestock," according to Anderson.

To make fertilizing pasture pay, manage grazing so more of what you grow actually gets eaten. Follow these tips:

Subdivide pastures with cross-fences and control when and where your animals graze.

Give animals access to no more than one-fourth, and preferably less, of your pasture at a time.

Graze off about one-half of the growth before moving to another subdivision.

If your pastures aren't already subdivided into at least four paddocks, your fertilizer dollar might be better spent on developing more cross-fences and watering sites.