Intercropping berseem clover with oats, barley or triticale

Intercropping berseem clover (Trifolium alexandrinum L.) with silage cereals may increase seasonal yield and improve forage quality. Berseem clover, an annual clover, was intercropped with oats (Avena sativa L.), barley (Hordeum vulgare L.) or triticale (X Triticosecale Wittmack) on a Black soil in Edmonton, Alberta. Several experiments were conducted to test the effects of seeding rate, cereal genotype and cutting date on intercrop performance.; The full-rate of cereals (240 plants m-2) was very competitive, and severely reduced berseem growth. As cereal density decreased in intercrops, silage-stage (Cut 1) yield decreased, berseem percentage in Cut 1 (BPI) increased, and regrowth of berseem (Cut 2) increased. The relationship between oat plant density and berseem dry matter (DM) fit a rectangular hyperbolic model. Increasing berseem seeding rates from 6 to 24 kg ha-1 decreased tillering in oats, but did not necessarily reduce oat DM yield.; Berseem-cereal intercrops produced total seasonal yields of 12--13 t ha-1 DM, with 2--3 t ha-1 DM as berseem regrowth after silage-stage harvest. Reducing cereal seeding rates to 25--35% of the full-rate improved forage quality without reducing seasonal yield. A 20% berseem component in Cut 1 improved the forage quality by decreasing neutral detergent fibre. Intercropping berseem with cereals extended the harvest window for silage production without sacrificing seasonal yield.; The ranking of barley (B), oat (O) and triticale (T) intercrops was generally: T highest for Cut 1 DM yield, T > O > B for BPI, B highest for Cut 2 DM yield, T = B = O for total DM yield, and B > T ≥ O for total protein yield. Differences between early-maturing oat intercrops (EO) and late-maturing oat intercrops (LO) were: LO ≥ EO for Cut I DM yield, EO = LO for total DM yield, and EO > LO for Cut 2 DM yield, total protein yield and BPI. Differences between semi-dwarf barley intercrops (S) and conventional-stature barley intercrops (C) were: C ≥ S for Cut 1 DM and protein yield, S ≥ C for BPI, S > C for Cut 2 DM yield, and S = C for total DM and protein yield. To maximize forage quality and increase growth for fall grazing, early-maturing and shorter-stature cultivars of cereals are recommended for berseem-cereal intercrops.