L. 2000. The effect of rejuvenation of Aspen Parkland ecoregion grass-legume pastures on dry matter yield and forage quality. Can. J. Plant Sci. 80: 781-791. A 3-yr study was conducted on Black and Gray Wooded soils at five different sites in the Aspen Parkland of Saskatchewan to determine the effect of spiking, burning, mowing, deep-banding (Trt) and applications of N, P, K and S liquid and granular fertilizers (Fert) on dry matter yield (DMY) and forage quality of primarily smooth bromegrass (Bromus inermis Leyss.) and alfalfa (Medicago sativa L.) pastures. Fertilizer application was a liquid form blended to provide 100 kg N ha-1 , 45 kg P 2 O 5 ha-1 , 23 kg K 2 O ha-1 and 12 kg S ha-1 in 350 kg of fertilizer ha-1. The experimental design at each site was a randomized complete block in a split-plot arrangement. Main plots were spike, burn, mow, deep-band, deep-band liquid fertilizer and control. The split-plot treatment was granular fertilizer broadcast at 0 and 350 kg ha-1 (providing 100 kg N ha-1 , 45 kg P 2 O 5 ha-1 , 23 kg K 2 O ha-1 and 12 kg S ha-1). All treatments were applied in the spring of 1994. Interaction effects of Trt × Yr and Fert × Yr were significant (P < 0.05) indicating a wide range of response to the rejuvenation methods among years. Spiking reduced (P < 0.05) DMY in year 1 at two sites. Deep-banding and mowing increased (P < 0.05) DMY at one site in year 3. Burning increased (P < 0.05) DMY in years 1 and 2 only at the Gray Wooded soil site. In year 1, liquid plus granular fertilizer (200 kg N ha-1) [deep-banded liquid fertilizer (DBLIQ at 100 kg N ha-1) + broadcast fertilizer (+F at 100 kg N ha-1 ] increased DMY at all sites by 84 to 185% over control plots. This effect carried over (P < 0.05) into year 2 at four sites but not the third and final year. The high rate of N (200 kg N ha-1) of the DBLIQ + F almost doubled (P < 0.05) crude protein content of year 1 forage, 170.3 g kg-1 compared with 96.4 g kg-1 for control. It was concluded that an application of broadcast or liquid fertilizer alone or combined with mechanical treatments will produce a significant effect on herbage yield and quality but only in the short term. Curry, P. et MacFarlane, L. 2000. Effet du rajeunissement des pâturages à mélange graminée-légumineuse dans la Tremblaie canadienne sur le rendement en matière sèche et sur la qualité du four-rage. Can. J. Plant Sci. 80: 781-791. Nous avons réalisé une expérience de trois ans sur sol noir (Chernozem) et sur sol gris boisé (Luvisol) à cinq emplacements différents de la Tremblaie canadienne en Saskatchewan, pour établir l'effet du travail au cultiva-teur profond, du brûlage des chaumes (BR), de la fauche (FA), du travail en bandes profondes (TBP) avec ou sans fumure liquide (LIQ) et des apports d'engrais NPKS sous forme liquide et granulaire, sur le rendement en matière sèche (rms) et sur la qualité fourragère de pâturages constitués essentiellement de brome inerme (Bromus inermis Leyss.) et de luzerne (Medicago sativa L.). Les engrais (F) étaient formulés de façon à fourn...

Declining productivity in older alfalfa (Medicago sativa L.) stands is an important problem in the Canadian prairies. Field trials were established in 1985 at three locations in Saskatchewan to examine the interaction of (i) harvest frequency, (ii) two alfalfa cultivars, (iii) in· oculation with one of three fungal pathogens (Coprinus psychromor· bidus, Phoma sc/erotioides, or Fusarium spp.), and (iv) K fertilization on survival and forage yield of alfalfa. Harvest and inoculation treat· ments were initiated in 1986 and continued each year until the tests were terminated in [1989][1990]. Plants were dug in spring and fall each year, and total nonstructural carbohydrate levels in the crowns were assessed using near infrared spectroscopy. Differences in plant nom· bers, stand density, persistence, and vigor between 'Nordica' (selected for resistance to C. psychromorbidus) and 'Beaver' were small. Harvest at 10% bloom (2-3 cuts) did not result in consistent reductions in numbers of plants, stand density, or total nonstructural carbohydrates relative to a single-cut treatment. Frequent harvest reduced vigor and first-cut yield of both cultivars in the year following the treatment, but caused larger reductions for Beaver than for Nordica. Total yields for the frequent harvests over all locations and treatments were 43% higher than for the single-cut treatment (5.3 vs. 3.7 Mg ha-1 ). Potas· sium fertility and inoculation with fungal pathogens had minimal im· pact on plant survival and yield. In conclusion, interactions among the factors which cause stand decline were minimal, and the reductions in plant vigor and first-cut yield resulting from frequent harvest were more than offset by the yield from late-season harvests.Abbreviations: TNC, total nonstructural carbohydrates.

New Australian-bred cultivars of subterranean (sub) clover with high levels of hardseededness are being promoted in New Zealand based on their superior performance in Australia. These new cultivars may not be suited to cooler New Zealand conditions. The "soft" seeded sub clover 'Denmark' dominated the hardseeded cultivar 'Rosabrook' in the second year of a dryland grazing experiment near Lincoln (630 mm mean annual rainfall), but in autumn of the third year the 'Rosabrook' population recovered to contribute 30% of total sub clover plants. A second field experiment, sown in March 2014 at Lincoln University, compared 10 sub clover cultivars sown with cocksfoot. 'Antas', 'Narrikup' and 'Woogenellup' were most productive at the September 2014 harvest. 'Antas', 'Woogenellup' and 'Leura' had the highest dry matter yields at the November 2014 harvest. In autumn 2015 'Narrikup' re-established most seedlings and 'Antas' the least. Until we have better knowledge of the production and persistence of "new" sub clover cultivars under New Zealand conditions, farmers are urged to sow binary mixtures (50:50) of a "new" plus an "older" cultivar. Keywords: cocksfoot, Dactylis glomerata, grazing experiment, hardseededness, re-establishment, Trifolium subterraneum

. 2004. Current and residual effects of nitrogen fertilizer applied to grass pasture on production of beef cattle in central Saskatchewan. Can. J. Anim. Sci. 84: 91-104. Four rates of nitrogen fertilizer (0, 50, 100 and 200 kg N ha -1 ) were applied for 4 yr to two replications of a 32-yr-old crested wheatgrass (Agropyron cristatum) pasture at Lanigan, Saskatchewan, after which no fertilizer was applied for a further 4 yr. The pastures were grazed by pregnant yearling Hereford heifers using a "put-and-take" stocking system. Soil cores (0-60 cm) were taken to monitor soil NO 3 -N concentrations either in early spring, before grass growth commenced, or in late fall, after grass growth had ceased. Pasture measurements included available forage at the start of the grazing season, total forage production and the concentrations of crude protein, acid detergent fiber (ADF), ash, Ca, P, Mg, K, Cu, Zn, Fe and Mn. Heifers, fistulated at the esophagus, were used in 1984 and 1985 to obtain samples of the grazed herbage, which were analyzed for organic matter digestibility (OMD), protein and minerals, except P and K. Heifer intakes of digestible organic matter (DOMI), protein and minerals, except P and K, were estimated from their concentrations in fistula extrusa and estimates of intake obtained from extrusa digestibility and fecal output using Cr 2 O 3 as a fecal marker. Phosphorus intake was estimated from fecal P concentration. Plasma samples were also collected and analyzed for concentrations of minerals.Soil NO 3 -N concentrations increased during the years of fertilizer application. One year after fertilizer application at 50 kg N ka -1 ceased, soil NO 3 -N was not significantly different from the control (P > 0.05) but soil NO 3 -N concentrations remained elevated for 4 yr following cessation of fertilizer applications on the 100 and 200 kg N ha -1 treatments (P < 0.05). Total forage production was increased by fertilizer application, but the magnitude of the response was determined by the amount of rainfall during the growing season (P < 0.001). Following cessation of fertilizer applications, the forage available at the start of three of four grazing seasons remained elevated by previous fertilizer applications (P < 0.05). Fertilizer increased the number of animal grazing days (AGD) and total livestock production (P < 0.05) in each year of application and in 3 of the 4 yr following withdrawal of fertilizer applications, the degree of the response depended on rainfall, but had no effect on the average daily gain of the heifers in any year (P > 0.05).Fertilizing crested wheatgrass pastures had little affect on the nutrition of the grazing heifers but plant maturation decreased (P < 0.05) the concentrations of most nutrients. The total utilization of nutrients was increased with increasing increments of fertilizer because of the increased stocking rates (AGD). It is therefore suggested that if the benefits of fertilizer application are to be captured it is important to increase the stocking rate. There was evidence of ...

), le brome inerme (Bromus inermis Leyss.), la fétuque élevée (Festuca arundinacea (Schreb.) Wimm.) et la phléole (Phleum pratense L.) afin de voir si ces espèces conviennent à la paissance. Les huit espèces ont été soumises à un pâturage de masse par des ovins, à raison de 30 bêtes par hectare. Les auteurs ont ensuite déterminé le stade physiologique des feuilles 7, 14 et 21 jours après la défoliation. Le brome inerme et la phléole donnent toujours le plus grand nombre de feuilles au terme des trois périodes examinées. La fétuque élevée se situe toujours à l'opposé avec le moins de feuilles. Cinquante-cinq pour cent des talles d'agropyre à chaumes rudes et 19 % des talles d'agropyre intermédiaire avaient atteint le stade de la reproduction 21 jours après la défoliation. Les auteurs ont ensuite réparti les graminées en trois groupes en comparant le stade de croissance des feuilles après paissance à leur aspect. Le brome des prés, le brome inerme et l'alpiste roseau obtiennent les meilleures notes; l'agropyre intermédiaire, l'agropyre à chaumes rudes et le dactyle pelotonné se retrouvent dans le groupe du milieu, tandis que la phléole et la fétuque élevée enregistrent la plus piètre performance.