Reevaluation of row spacing/plant density of seeded pasture grasses for the semiarid prairie

Abstract

. 1998. Reevaluation of row spacing/plant density of seeded pasture grasses for the semiarid prairie. Can. J. Plant Sci. 78: 257-264. Previous research in the semiarid prairie at Swift Current, Saskatchewan, indicated that optimum row spacing for forage production was 60 or 90 cm for crested wheatgrass (Agropyron cristatum [L.] Gaertner) and Russian wild ryegrass (Psathyrostachys juncea [Fisch.] Nevski). However, recent research suggested that harvest method affects forage yield estimates from row spacing experiments. An experiment with three row spacings of mixtures of alfalfa (Medicago sativa L.) with crested wheatgrass and Russian wild ryegrass was harvested mechanically and by hand. Yield differences between methods of harvesting were affected by row spacing; larger differences were observed at 15 cm than at 60 cm spacing, particularly for Russian wild ryegrass. The highest hand-harvested forage yield estimates were observed in the narrowest row spacing. In a second experiment, plant density was evaluated for the same grasses using square grid spacings of 30, 45, 60, 75 and 90 cm. Decreasing plant density was associated with decreased hand-harvested forage yield in both species. In a third experiment, 60-and 90-cm row spacing resulted in more seed heads and lower leaf content than 30-cm row spacing. Leaf digestibility increased slightly with increased row spacing. These results suggest that 30-cm row spacing should be recommended to producers for sustainable pastures in the semiarid prairie region. ] Nevski) pour la production fourragère. Des recherches plus récentes suggèrent cependant que la méthode de récolte influe sur les rendements fourragers calculés à partir des expériences sur la largeur des interlignes. Nous avons donc réalisé une expérience à trois largeurs d'interligne sur des associations de luzerne (Medicago sativa L.) et d'agropyre à crête ou d'élyme de Russie dans laquelle la récolte se faisait soit à la machine soit manuellement. Les différences de rendement attribuables aux méthodes de récolte variaient selon la largeur de l'interligne, elles étaient plus prononcées à l'écartement de 15 cm qu'à celui de 60 cm, en particulier pour l'élyme de Russie. Le plus fort rendement de fourrage récolté à la main allait à l'écartement le plus étroit. Dans une deuxième expérience, la densité de peuplement était évaluée sur ces mêmes graminées, utilisant pour chaque espèce des espacements équidistants de 30, 45, 60, 75 et 90 cm entre les plantes. Une diminution de la densité de peuplement était associée chez les 2 espèces à une baisse de rendement fourrager récolté à la main. Dans une troisième expérience, les écartements de 60 et de 90 cm entre les lignes donnaient lieu à une plus abondante production d'inflorescences et à une moindre proportion de feuilles dans le fourrage que l'écartement de 30 cm. La digestibilité des feuilles augmentait légèrement à mesure que l'interligne s'élargissait. Il ressort de ces observations que 30 cm est la largeur d'interligne qu'il faudrait recommander aux producteurs de...

Efeitos de métodos de estabelecimento de braquiária e estilosantes e de doses de calcário, fósforo e gesso sobre alguns componentes nutricionais da forragem

“…O revolvimento do solo permite a maior infiltração de água, maior atividade de microorganismos e melhor aeração do solo favorecendo a mineralização do N potencialmente mineralizável, aumentando a disponibilidade desse nutriente para as plantas. Jefferson & Kielly (1998) enfatizaram que, em situações de baixas densidades de plantas, aumentos nas concentrações de N são esperados, pois nessa condição ocorre menor competição pelo N mineralizado do solo.…”

“…A menor concentração de FDN foi obtida com o estabelecimento em três etapas no espaçamento de 1,0 m entre linhas, no qual também registrou-se menor número de perfilhos (Tabela 5). Aumentos nas distâncias entre linhas podem reduzir a proporção de folhas e aumentar os perfilhos reprodutivos e, conseqüentemente, elevar as concentrações de celulose e lignina (Jefferson & Kielly, 1998), produzindo uma forragem com maior concentração de FDN. Na maioria das colheitas, não houve ajuste de regressão entre doses de P 2 O 5 e concentrações de P na MS da braquiária, para os vários modelos testados (linear, quadrática, cúbica, exponencial, raiz quadrada e logarítmica).…”

Biomass Yield, Phenology, and Survival of Diverse Switchgrass Cultivars and Experimental Strains in Western North Dakota

“…Each plot consisted of five rows 6.1 m long with a 35‐cm spacing between rows at the two Mandan sites and a 46‐cm row spacing at Dickinson. The relatively wide row spacings are a recommended practice in semiarid regions (Jefferson and Kielly, 1998). Seeding rate was 130 pure live seeds per lineal meter of row (approximately 6.0 to 7.0 kg pure live seeds ha −1 ).…”

Short-lived intercrop forages affect long-term yields of alfalfa and wildrye grass mixtures

“…Long-term productivity in this region (Kilcher 1961;Lawrence and Heinrichs 1968;Leyshon et al 1981) is increased by growing forages in rows spaced 60 cm or more apart. Although higher hay yields can be obtained from these wide row spacings (Leyshon et al 1990;Jefferson and Kielly 1998), new stands take 3 to 5 yr to reach maximum productivity (Leyshon et al 1981).…”