Barley after hay: grass matters!

Non-Peer ReviewedPerennial forage crops are not traditionally grown in crop rotations in the Brown soil zone for several reasons: i) they are slow to establish; ii) they require intensive tillage to terminate; and iii) they reduce yield of subsequent crops. Short-lived perennial forages that possess rapid establishment characteristics could be used for 3 years of hay production with easier rotation to an annual crop. An experiment seeded in 1998 at the Semiarid Prairie Agricultural Research Centre with three short-lived grasses grown in monoculture or with two alfalfa cultivars was terminated by herbicide or tillage in May 2002, and subsequently seeded to barley. Visual observations prior to stand termination indicated that slender wheatgrass (SWG) and Dahurian wildrye (DWR) ground cover had declined but intermediate wheatgrass (IWG) was generally over 90% of the original. Barley yield was 17 bu/ac on plots previously in IWG compared to 26 and 28 bu/ac on plots previously in DWR and SWG, respectively. IWG reduced straw yield, harvest index, and test weight compared to SWG and DWG. Grass mixtures with Beaver alfalfa yielded 30 bu/ac compared to 21 and 19 bu/ac for Nitro alfalfa and grass monocultures. Barley grown on previously Beaver alfalfa mixtures also had higher straw yield, harvest index, and test weight compared to that grown on plots from the other two mixtures. These preliminary results suggest that short-lived grasses (DWR and SWG) may fit in crop rotations better than longer lived species (IWG) and that inclusion of alfalfa may, in fact, increase subsequent barley yields in this semiarid region