High nitrogen prices have many growers reconsidering forage nitrogen management, say University of Missouri experts. High nitrogen prices make over-application more costly, but hay and beef prices have also increased, meaning the costs for under-application have increased. These factors mean the value of good management has never been higher, they say.

High fertilizer prices favor farmers who harvest high-quality hay and maximize forage utilization on pastures, according to John Lory, environmental nutrient management specialist, and Rob Kallenbach, extension forage specialist. They advise growers that the core rules for making nitrogen fertilizer pay in forage systems are to fertilize when the plant has a capacity to respond, and to maximize forage utilization.

Fertilizer prices have been increasing steadily since 2002. National Ag Statistics Service data shows nitrogen prices have essentially doubled in the past five years. Prices are projected to be 30% higher this spring than last.

Lory and Kallenbach say growers should adopt management practices that increase forage utilization in pastures, such as management intensive grazing. It increases the nitrogen value of manure returned to the pasture by grazing animals. They estimate growers can reduce recommended nitrogen rates 20% for the same yield goal on intensively managed pastures. They also recommend growers only fertilize when increased forage production is needed. Cool-season grasses respond to spring fertilizer, but growers should think carefully about whether the excess spring production is necessary unless the excess production is going to be harvested as hay.

Alternate sources of nitrogen, such as legumes, can be considered for pastures. Manure may also be a more economical source of nutrients. Manure nitrogen is typically 50-60% available when surface-applied, but 100% of manure phosphorus and potassium are available to the crop.

Lory and Kallenbach offer additional pasture nitrogen suggestions in the most recent issue of the University of Missouri Integrated Pest & Crop Management newsletter, online at ppp.missouri.edu/ipm/index.htm/.