ten, 1982a). Barley forage was highest in digestible DM and lowest in acid detergent fiber (ADF) concentra-Oat (Avena spp.) is a popular cereal forage in cool semiarid regions. tions. Crude protein concentration was 16 g kg Ϫ1 greater Barley (Hordeum vulgare L.) has produced equal or greater amounts of superior quality forage in subhumid regions. The importance of in barley forage than in oat forage. cereal crop, cultivar, and plant part on forage production was deter-The superior quality of barley forage compared with mined in low-soil-N environments in southwestern North Dakota. oat and other cereal forages may result from a greater Barley and oat cultivars, along with intercrops of pea (Pisum sativum proportion of DM occurring as inflorescence in barley. L. subsp. sativum) with barley and oat, were compared for forage More than 25% of barley forage DM consisted of infloyield and quality over 2 yr. Forage dry matter (DM) yield averaged rescence compared with 20% for oat, triticale, and wheat 3.84 Mg ha Ϫ1 for oat compared with 2.91 Mg ha Ϫ1 for barley while forage across six maturity stages in subhumid regions crude protein (CP) concentration of oat forage averaged 61 g kg Ϫ1 (Cherney and Marten, 1982b). The inflorescence was compared with 90 g kg Ϫ1 for barley (P Ͻ 0.05). No difference in forage more digestible and nutritious than other plant compo-N yield occurred between barley and oat. Acid detergent fiber and nents. The leaf blade and sheath of barley also had less neutral detergent fiber concentrations averaged 39 and 41 g kg Ϫ1 lower, respectively, for barley compared with oat forage while Ca lignified area than oat. Similar compositional data are and P concentrations were higher for barley forage. Cultivar selection not available for barley and oat cultivars grown in the within each crop species generally did not affect forage yield or quality.Northern Great Plains. The relative contributions of stem, inflorescence, leaf blade, and leafThe CP concentrations of barley and barley-pea forsheath to forage yield were similar between cereal species and average were superior to those of oat and oat-pea forage in aged 20, 44, 14, and 22%, respectively. Intercropping with pea ina study at Dickinson, ND (Carr et al., 1998). Additional creased forage and N yield. These results suggest that forage yield is cereal forage quality data have been compared in subreduced but quality is enhanced when oat is replaced with barley in humid regions (Cherney and Marten, 1982b) but not in low-soil-N, unfertilized environments. Furthermore, the results indithe Northern Great Plains. Factors in addition to CP cate that forage yield and quality can be enhanced by intercropping concentration are important in determining the nutritive barley or oat with pea.

Barley (Hordeum vulgare L.) and oat (Avena sativa L.) have been intercropped with field pea [Pisum sativum subsp. sativum var. arvense (L.) Poir.] to increase forage yield and quality. Our objective was to evaluate the effects of two barley and two oat cultivars and seeding rates of cereal—pea intercrop on forage production, crude protein (CP) concentration, and N yield. A field experiment was conducted in 1993 and 1994 under dryland management in both fallowed and continuously cropped, no‐tillage environments. ‘Bowman’ and ‘Horsford’ barley, and ‘Dumont’ and ‘Magnum’ oat, were each sown at 93, 185, and 278 kernels m−2 with ‘Trapper’ pea at 40, 80, and 120 seeds m−2, in all possible rate combinations. The cereal cultivars also were sown alone at 185 kernels m−2. Cultivars developed for forage production (Horsford, Magnum) produced as much or more forage than cultivars developed for grain production (Bowman, Dumont) across sole‐crop and intercrop plots (P ≤ 0.05). Forage yield was unaffected by intercropping when the cereal crop was sown at the sole‐crop or greater rate. Less forage was produced by intercrops when the cereal component was sown at half the sole‐crop rate. Forage yield was not affected by the pea seeding rate, but CP concentration increased with increasing seeding rate of pea in three of four environment‐years. Forage N yield was unaffected by intercropping. These data indicate that the cereal component in barley—pea and oat—pea mixtures should be sown at a sole‐crop or greater seeding rate for maximum forage production. Forage CP concentration can be increased as the relative proportion of pea seed to cereal kernels sown in a mixture is increased, but forage N yield may not be affected, since the cereal component contributes more to yield than the pea component.

crop residue at the soil surface and subsequently cool spring soil temperatures, both of which contribute to Tillage is declining in wheat production systems in the Great Plains.immobilization of soil N (Westfall et al., 1996). How-Our objective was to determine if a tillage ϫ cultivar interaction ever, following an adjustment period, greater amounts occurred for grain yield, protein concentration, kernel weight, and test weight for hard red spring wheat (Triticum aestivum L. emend. P.M. Carr and W.W. Poland, North Dakota State Univ., Dickinson Cultivar differences across and even within studies may Res. Ext. Ctr., 1089 State Ave., Dickinson, ND 58601; R.D. Horsley, have contributed to the inconsistency in yield response Dep. Plant Sci., North Dakota State Univ., Fargo, ND 58105. This to changes in tillage. paper is a contribution of the North Dakota State Univ. Agric. Exp. Stn.