NITROGEN EFFECTS ON YIELD, BETA-GLUCAN CONTENT, AND OTHER QUALITY FACTORS OF OAT AND WAXY HULLESS BARLEY

Oat (Avena sativa L.) and waxy hulless barley (Hordeum vulgare L.) are important sources of water soluble plant fiber (beta-glucan) needed i n human diets to lower serum cholesterol, Recent studies have shown gr ain beta-glucan content is influenced by soil type and environment, ho wever, nitrogen (N) response data for oat and waxy hulless barley are lacking. In this study, we evaluated N effects on grain beta-glucan co ntent and yield; grain yield, protein content, and test weight; and to tal dry matter production and N utilization of oat and waxy hulless ba rley. Rates of applied N were 0, 34, 67, and 101 kg N/ha at three fiel d environments in central Montana during 1989 and 1990. Nitrogen incre ased all variables except test weight and beta-glucan content. Waxy hu lless barley grain yields fluctuated from 0.82 to 4.11 Mg/ha, beta-glu can content from 62 to 76 g/kg, and beta-glucan yields from 51 to 354 kg/ha. Oat yields ranged from 0.85 to 3.83 Mg/ha, beta-glucan content from 37 to 51 g/kg, and beta-glucan yields from 35 to 178 kg/ha. Oat b eta-glucan content was positively related to grain protein content, an d waxy hulless barley beta-glucan content was positively related to te st weight. beta-glucan content appeared more related to environmental factors other than N.