Peterson*, K. 1 , Heaton, K.M. 2 , Smith, R. 3 , Waldron, B. 4

1. Evaluating Forage Yield of Nitrogen Fertilized Pastures Compared to Legume Inter-seeded Pastures in an Attempt to Reduce Fertilization Costs Peterson*, K. 1, Heaton, K.M. 2, Smith, R. 3, Waldron, B. 4 1Utah State University Extension Intern, Panguitch High School Garfield County, P.O. Box 596, Panguitch, UT 84759, katelyn.peterson12@hotmail.com 2 Agriculture Agent/ County Director, Utah State University Extension Kane/Garfield County, P.O. Box 77, Panguitch, UT 84759, kevin.heaton@usu.edu 3Forage and Range Research Agronomist, Agricultural Research Service, 690 N. 1100 E. Logan, UT 84322-6300, rob.smith@ars.usda.gov 4Research Geneticist, Agricultural Research Service, Utah State University Forage & Range Research Lab, Logan, UT 84322-6300, blair.waldron@ars.usda.gov Abstract: Twelve research plots funded by Western Region Sustainable Agricultural Research and Education Foundation were planted in May 2010 on the Utah Agriculture Experimentation Station Panguitch Farm located in Garfield County, Utah. These plots were evaluated for production May through September 2011. After each harvest samples were dried, weighed, and yields were calculated and analyzed. Fertilized plots produced the highest yield followed closely by the unfertilized plots. Alfalfa was the next highest yeilding and birdsfoot trefoil produced the lowest weight. Although the results from this study suggest that nitrogen fertilization of pasture is not economically feasible, however more data is needed to determine a more accurate conclusion Introduction: High fertilizer costs and emphasis on environmental stewardship has renewed interest in the grass-legume pasture. Reports prior to the 1960’s consistently showed increased forage and animal gains when including legumes in pastures. However, grass-legume mixtures lost popularity due to inexpensive fertilizer and single species dominance in continuous grazing systems. Bloat is also an issue when legumes are inter-seeded in grass pasture. Grass-legume pasture plots were planted on May 25th 2010 to investigate economic and environmental sustainability of livestock production utilizing grass-legume pastures. • Discussion/Results: • The greatest average yield was produced by the fertilized plots, followed closely by the unfertilized plots, which was surprising. Alfalfa was third with birdsfoot trefoil producing the lowest weight. • Nitrogen fertilizer applications were initiated after the first harvest in May. The May harvest contributed a significant amount of forage to the overall study, which is logical because of the winter moisture and available nutrients. • Nitrogen fertilization increased production by approximately 300 lbs./acre over the unfertilized control and by over 350 lbs/acre over the birdsfoot trefoil treatment. • All treatment yields tended to decrease as the season progressed. However, nitrogen fertilization helped offset the late season slump in production. • The birdsfoot trefoil did not establish well and thus plots could be considered an unfertilized treatment. • The cost for fertilizer was $92.00/acre and the application rate was estimated at $6-7/acre. The $99 fertilizer cost/acre provided approximately 300 lb./acre increase in forage. This forage based on a tonnage costs over $660/ton, while good quality alfalfa hay is only $225/ton. Yield by Treatment • Methods: • Pasture plots established in May 2010 consisted of four different treatments in a randomized block design with three replications. • The tall fescue/meadow brome pasture plots included the following treatments: fertilizer (P/F), no fertilizer (P/No Fert), alfalfa legume (P/Alf), and birdsfoot trefoil non-bloating legume (P/BFT). • Yields were obtained by clipping a ½ meter square to a two inch stubble height using hand clippers. Harvest dates were May 31, July 5, August 8, and September 7. Harvested samples were dried in a drying oven and weighed. Yields were then calculated and analyzed. • After each harvest, cattle grazed all the plots to a four inch stubble height. • After grazing, the plots were mowed to a three inch stubble height with a sickle bar mower. • Nitrogen fertilizer was applied to the fertilizer treatments after each harvest at the rate of 30 pounds of nitrogen per acre. • Plots were irrigated with 3 inches of water every ten days by hand lines. Total Yield by Treatment Graphs: Yield by Month • Conclusion: • The fertilized treatments provided the greatest yield. • Birdsfoot trefoil did not establish or thrive well in a cool high elevation environment and would have been an “unfertilized/non legume plot.” • Nitrogen fertilization is not economically feasible because of the high input costs with only small increases in production. • More data is needed to determine a stronger and more accurate conclusion. Field work will continue in 2012.