Interseeding Kura clover and birdsfoot trefoil into existing cool-season grass pastures

Legumes in cool-season grass pastures fan improve productivity and quality. In May of 1997 and 1998, a split-split plot field experiment with six repl ications was planted in Morris, MN to evaluate the effect of sod suppressio n, planting method, and legume species on establishment of legumes into exi sting cool-season grass pastures and to evaluate kura clover (Trifolium amb iguum Bieb.) and birdsfoot trefoil (Lotus corniculatus L.) as potential Spe cies for interseeding in the North Central region. Whole-plot sod suppressi on treatments were (i) 0.62 kg a;i. ha(-1) glyphosate [isopropylamine of N- (phosphono-methyl) glycine] or (ii) no glyphosate. Subplot planting methods were (i) no-till drilling, (ii) broadcasting seed on the soil, (iii) broad casting seed followed by harrowing, and (iv) broadcasting seed followed by a Light dishing. Legume species sub-subplots were (i) alfalfa (Medicago sat iva L.), (ii) red clover (Trifolium pratense L.), (iii) kura clover, and (i v) birdsfoot trefoil. Stand data were collected in the fall of the planting ear and in the spring of the second growing season. Averaged across planti ng methods and species,legume stands were 38% where glyphosate was used and 3% where it was not. No differences or interactions were detected for plan ting method (P > 0.12). In this study, if competing vegetation was suppress ed, stands were >31% regardless of planting method, When sod was suppressed , alfalfa established better stands than the other legume species. The over riding factor in the ability to:establish legumes in this study was the sup pression of existing vegetation during establishment.