There are many thoughts regarding how much nitrogen is lost from applying urea on pastures and hay fields. If applied incorrectly, up to 40 percent of the nitrogen applied as urea can be vaporized and lost as a gas.
A high percentage of the grazing land in our area is native grass. Most ranchers do not fertilize native grass because it is widely thought that it is unprofitable to do so. In fact, one of the appealing characteristics of native grass systems is that they do relatively well with minimal inputs.
A well-managed and properly stocked pasture should not need herbicides every year. A little time spent scouting may save you a lot of unnecessary time and money on spraying when your weed population is not high enough to justify it.