Forage potential of intercropping berseem clover with barley, oat, or triticale

Intercropping berseem clover (Trifolium alexandrinum L.) with silage cereals may increase forage yield and quality. Berseem clover was intercropped with barley (Hordeum vulgare L.), oat (A vena sativa L.), or triticale (x Triticosecale rimpaui Wittm.) at 30, 60, 90, 120, and 240 cereal plants m(-2) at Edmonton, Alberta, from 1998 to 2001. Cereals dominated Cut 1 (silage-stage) yield, and berseem clover dominated regrowth yield. As cereal density decreased from 240 to 60 plants m(-2), Cut 1 yield decreased from 10.5 to 9.3 Mg ha(-1) dry matter (DM), berseem clover percentage of Cut 1 increased from 5 to 14%, and berseem clover regrowth yield (Cut 2) increased from 1.8 to 3.0 Mg ha(-1) DM. Total season intercrop yields with barley or oat at 60 plants m(-2) were yields with 240 plants m(-1). Total season intercrop DM yields did not differ among the three cereal species in 3 of 4 yr. Triticale intercrops had advantages of greater Cut 1 yield and greater berseem clover percentage in Cut 1. Barley intercrops had advantages of greater Cut 2 yield and greater total season protein yield. Greater Cut 2 yield with barley intercrops was related to earlier silage-stage (Cut 1) harvest date. Intercropping berseem clover with reduced seeding rates of cereals improved Cut 1 forage quality. When berseem clover was 20% of Cut 1 yield, neutral detergent fiber was 25 to 45 g kg(-1) less than with cereals alone. The crude protein of berseem clover regrowth averaged 210 g kg(-1), providing high quality late-season forage.