As corn and soybean production become more profitable, pasture land could become more limited, increasing the importance of forage production in remaining pastures.
Stephen Barnhart, Iowa State University Extension forage agronomist, says that pasture fertilization can be one of the easiest and most economical ways to increase carrying capacity.
Grass-based pastures generally respond very efficiently to the first 40 to 50 pounds per acre of nitrogen, according to Barnhart. Bluegrass will continue to respond to nitrogen applications up to 150 to 180 pounds per acre annually, but at a decreasing rate of response. Tall cool-season grasses such as bromegrass, orchardgrass and tall fescue respond to nitrogen levels of 250 to over 300 pounds per acre. Generally, an initial application in the early spring should be followed with lighter applications in late spring and/or late summer. In legume-grass mixed pastures, high or frequent applications of nitrogen will make the grass component more competitive. To encourage a greater legume presence, use modest nitrogen rates and limit application to summer or fall.