Yoana C. Newman1, James P. Muir2, Gerald Evers3, Gerald R. Smith4, Thomas W. Neyland5, Michael Gage5, and Robert J. Scott5. (1) University of Florida - Agronomy Department, 305 Newel Hall, Gainesville, FL 32611, (2) Texas Agricultural Experiment Station, 1229 North U.S. Hwy 281, Stephenville, TX 76401, (3) Texas Agricultral Experiment Station, PO Box 200, Overton, TX 75684-0200, (4) Texas A&M System, Texas AgriLife Research, TAMU Agric. Res. & Ext. Ctr., PO Box 200, Overton, TX 75684-0200, (5) Texas Cooperative Extension, St. Mary's St., Centerville, TX 75833
The overseeding of cool-season legumes complements forage distribution when used in association with warm-season perennial grasses and could be an alternative to N fertilization. Three on-farm studies were conducted using applied research/demonstration plots. Cool-season legumes and ryegrass were overseeded into warm-season perennial grass plots. Treatments were arranged in a split plot design where main plots were overseeded or not with ryegrass and subplots corresponded to cool-season legume overseeding treatments including a control (no legume overseeding) and an N fertilization (90 kg N ha-1) treatment. A second set of plots arranged in similar fashion were planted but were not harvested. They were used for demonstration purposes only. Plots in the location reported (latitude 32° 5’N; 97° 6’W; soil pH 7-8) were overseeded in late November in 2005 and early November in 2006 and they were mechanically defoliated in April each year. Ryegrass increase shoot yields (grasses + legume) of the legume overseeded plots (86 – 257% range) and legume overseeding contributed a 28% to 150% increase over the 90 kg N fertilized treatment yield in 2005. A 25 to 140% increase range compared to the N-fertilized treatment was observed in 2006. Overseeding with cool-season legumes provided yields that were equivalent to a medium N fertilization and seems to be a viable alternative to N fertilization when planting adapted species.
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