Seasonal nitrogen effects on nutritive value in binary mixtures of tall fescue and bermudagrass |
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| Authors: | J J Read D J Lang G E Aiken |
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| Affiliation: | 1. Genetics and Sustainable Agriculture Research Unit, USDA‐Agricultural Research Service, Mississippi State, MS, USA;2. Department of Plant and Soil Sciences, Mississippi State University, Mississippi State, MS, USA;3. Forage‐Animal Production Research Unit, USDA‐Agricultural Research Service, Lexington, KY, USA |
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| Abstract: | The addition of cool‐season, tall fescue Lolium arundinaceum (Schreb.) Darbysh.], to warm‐season, bermudagrass Cynodon dactylon (L.) Pers.], pastures can improve forage productivity and nutritive value. Effects of four binary mixtures consisting of cv. Flecha (incompletely summer dormant) and cv. Jesup (summer active) tall fescue overseeded into established stands of cv. Russell and cv. Tifton 44 bermudagrass and three seasonal N treatments were evaluated on dry‐matter (DM) yield, crude protein (CP), in vitro true digestible DM (IVTDDM), acid detergent fibre (ADF) and neutral detergent fibre (NDF). Nitrogen‐timing treatments were 168 kg N ha?1 (as ammonium nitrate) split into three applications per season with an additional 8·6 t ha?1 of broiler litter (as‐is moisture basis) split into two applications varied to favour either tall fescue (in October and January), bermudagrass (in March and May) or both grasses (in January and March). Treatment effects were determined in samples of mixed herbage harvested in April, May, July, August and September of 2009 and 2010. Regardless of bermudagrass cultivar, herbage DM yield was greater (P < 0·05) in Flecha–bermudagrass than Jesup–bermudagrass in July of both years and in August 2010. Nutritive value generally was greatest in Jesup–Tifton 44, based on high CP and IVTDDM, and low ADF and NDF. Averaged across mixtures, avoiding fertilizer N and litter applications beyond April increased (P < 0·01) DM yield in April and May and IVTDDM in July (603 vs. 629 g kg?1; 2‐year average) and August (618 vs. 660 g kg?1) compared with applications in January–July. The timing of N and broiler litter applications on tall fescue–bermudagrass to favour growth of tall fescue appeared to increase fescue cover during the cool season and nutritive value of the mixed herbage during the warm season. |
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| Keywords: | fertilization forage crop ecology manure management mediterranean tall fescue nitrogen nutritive value poultry litter |
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