As alfalfa (Medicago sativa L.) stands deteriorate, invading weeds compete with alfalfa and further reduce alfalfa yield. Some growers in the northern Great Plains region attempt to renovate alfalfa with intensive cultivation during spring. Research was initiated near Rapid City, SD in the fall of 1993 to determine the effects of cultivation on weed control, yield, plant density, and longevity of alfalfa stands. Cultivation treatments consisted of spike tooth harrow, spring tooth harrow, tandem disk and Triple K harrow. Herbicide treatments included Metribuzin and Pursuit and were applied 10 November 1993. Cultivation treatments were conducted 13 April 1994 when alfalfa was breaking dormancy. Subsamples were hand separated to determine the composition of alfalfa, grasses, and broadleaf weeds.

Total herbage yield in May 1994 ranged from 232 g m^-2 for the spike tooth harrow treatment to 156 g m^-2 for the Triple K harrow. The proportion of alfalfa, however, from the Triple K harrow was the highest with 860 g kg^-1. Herbicide treatments had 600 and 720 g alfalfa kg^-1 dry matter for Metribuzin and Pursuit, respectively. In August 1994, total herbage yield ranged from 249 g m^-2 for the spring tooth harrow to 139 g m^-2 for the tandem disk treatment. Herbicide treatments contained 920 and 790 g alfalfa kg^-1 dry matter for Metribuzin and Pursuit, respectively. Alfalfa plant population density ranged from 189 plants m^-2 for the spike tooth harrow to 120 plants m^-2 for the Triple K harrow. None of the cultivation or herbicide treatments were significantly different from the untreated control for any measurement. These initial results suggest that attempting to renovate alfalfa stands with cultivation practices does not increase forage yield, control weeds, or increase alfalfa plant population density.