Research Interests
My research program involves evaluating the influence of forage quality and grazing management on beef nutrition and production in the southeast. Through the implementation of a number of applied research evaluation methods, my current program has a strong focus on the utilization of alfalfa interseeded into bermudagrass and the associated effects on beef nutrition. Working at the animal-plant interface, I conduct small and large scale plot studies followed by large-scale grazing evaluations on predominately perennial warm season grass based pastures. I also work closely with colleagues within and across departments at UGA, USDA-ARS, and at various southeastern universities to develop strong teams focused on a systems approach to answering complex beef-forage related questions. Additional associated work include evaluations of annual forage species, effects of yield and harvest timing on forage quality, effects of harvest method and prolonged storage on nutritive value of forage products, and the associated effects on beef cattle nutrition. The main objective of my program is focused on improving beef nutrition and forage quality and utilization while extending the grazing season.
Extension Interests
The focus of my Extension program is on improving beef cattle production and efficiency within beef cattle management systems of the southeast. My goal is to provide education and guidance that leads to better decision making associated with forage based livestock production, specifically as it relates to forage management, beef nutrition, and feeding strategies.
Program Objective
The overall objective of my program is to streamline research and extension efforts through applied research evaluations that provide timely and applicable management strategies to the end-user; Resulting in improved beef nutrition and grazing management and extended grazing across the Southeast.
Selected Recent Publications
Hancock, D.W., U.K. Saha, J.J. Tucker, and R.L. Stewart Jr. 2016. Observations of High Nitrate Concentrations in Forage Bermudagrass during Severe to Exceptional Drought Years. AJPS 2016 Mar. 7: 695-701.
Knoll, J.E., J.M. Johnson, P. Haung, R. D. Lee, W.F. Anderson. 2015. Effects of delayed winter harvest on biomass yield and quality of napiergrass and energycane. Biomass and Bioenergy 2015 Sept. 80: 330-337. doi:10.1016/j.biombioe.2015.06.018. Epub 2015 July 1.
Knoll, J.E., J.M. Johnson, R.D. Lee, W.F., Anderson. 2014. Harvest Management of ‘Tifton-85’ Bermudagrass for Cellulosic Ethanol Production. BioEnergy Research, doi 10.1007/s12155-014-9449-1.
Enloe, S.F., J. Johnson, M. Renz, H. Dorough, and K. Tucker. 2014. Hairy buttercup control and white clover tolerance to pasture herbicides. Forage & Grazinglands, doi 10.2134/FG-2013-0013-RS.
G.E. Aiken, J.L. Klotz, J.M. Johnson, J.R. Strickland, and F.N. Schrick. 2013. Postgraze assessment of toxicosis symptoms for steers grazed on toxic endophyte-infected tall fescue pasture. J. ANIM SCI 2013 Dec: 91(12):5878-84. doi: 10.2527/jas.2012-5964. Epub 2013 Oct 14.
J.L. Klotz, G.E. Aiken, J.M. Johnson, K.R. Brown, L.P. Bush, and J.R. Strickland. Antagonism of lateral saphenous vein serotonin receptors from steers grazing endophyte-free, wild-type, or novel endophyte-infected tall fescue. J. ANIM SCI 2013, 91(9):4492-4500 doi: 10.2527/jas.2012-5896. Epub 2013 Jul 3.
J.M. Johnson, G.E. Aiken, T.D. Phillips, M. Barrett, J.L. Klotz, and F. N. Schrick. Steer and Pasture Response for a Novel Endophyte Tall Fescue Developed for the Upper Transition Zone. J ANIM SCI 2012, Jul: 90(7):2402-9. doi: 10.2527/jas.2011-4493. Epub 2012 Jan 27.