NITROGEN AND LEGUME MANAGEMENT IN SOUTHEASTERN WILDRYE

摘要

Southeastern wildrye (Elymus glabriflorus) is a native, cool-season, perennial grass that, until recently, has been relatively un-researched. In order to validate and quantify this species' potential as a forage crop, applied agronomic studies are required. Field trials were established in the fall of 2014 to compare annual legumes and synthetic nitrogen applications in southeastern wildrye stands. Locations for this study include Starkville and Newton, Mississippi. The study was designed in a randomized complete block with four replications. Five annual clover treatments (arrowleaf, balansa, ball, berseem, and crimson clover) and five nitrogen treatments (0, 50, 100, 150, and 200 lbs total N/acre) were evaluated. Nitrogen was applied in split applications following each harvest. Data collection included plant heights, botanical composition, botanical ratings, normalized differential vegetation index (NDVI; nitrogen treatments only), biomass yields, and forage quality analysis. Forage quality analysis included acid detergent fiber (ADF), neutral detergent fiber (NDF), crude protein (CP), and total digestible nutrients (TDN). Also, nitrogen use efficiency was calculated for nitrogen treatments. Following one year of data collection (three harvests), southeastern wildrye was found responsive to the higher rates of applied nitrogen, with dry matter (DM) yields ranging from 1210 to 5173 lbs/acre DM across treatments. However, annual clover treatments produced similar DM yields with superior nutritional characteristics, including CP (15-21%), lower ADF (27-32), and lower NDF (38-53), making them a viable alternative to nitrogen fertilizer.