Italian ryegrass (IRG) (Lolium multiflorum Lam. cv. Lemtal) was grown on a sandy loam and/or on a fine sandy loam in 1974, 1975, and 1976. IRG was fertilized three times each year with 40, 80, or 120 kg N/ha/application and harvested at 3-, 4-, 5- or 6-wk intervals starting in July. Dry matter (DM) yield increased with the rate of applied N. Four-week harvest intervals generally resulted in the greatest DM yields ranging from 4.32 to 7.11 t/ha. Droughty conditions in 1975 reduced the growth and resulted in small DM yields particularly on sandy loam. The mean total N concentrations of IRG ranged from 2.40 to 3.68% and was approximately proportional to applied N. Longer regrowth intervals decreased total N concentrations by. 12–.56% units per week. Applied N did not influence the in vitro disappearance of DM (IVDDM), whereas longer regrowth intervals reduced IVDDM in 1975. The harvest system with a 4-wk regrowth interval and 80 kg N/ha/apphcation resulted in satisfactory DM, N, and digestible DM yields and appeared to be a suitable system for IRG grown as a summer annual.