The effect of rejuvenation of Aspen Parkland ecoregion grass–legume pastures on dry matter yield and forage quality

Abstract

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...

The biology of Canadian weeds. 134. Bromus inermis Leyss

“…Severe defoliation may delay regrowth by removing the growing points of tillers and activating rhizome buds (Carlson and Newall 1985;Van Esbroeck et al 1995), and lead to the infestation of smooth brome pastures by shepherd's purse [Capsella bursa-pastoris (L.) Medic.] and dandelion (Taraxacum officinale Weber;Harker et al 2000;Lardner et al 2000). Defoliation may also decrease the pollen yield and the number of florets per spikelet (McKone 1989 (Neiman and Manglitz 1973;Carlson and Newall 1985).…”

“…Immobilization of nutrients in plant litter (Lardner et al 2000) and increasing stand density often reduce the productivity of older populations (Alberta Agriculture Food and Rural Development 1981). Decline in plant vigour leads to an increase in self-sterility (Kirk 1934), and older plantings of smooth brome produce fewer flowering panicles (Newell 1951).…”

The effect of rejuvenation of Aspen Parkland ecoregion grass-legume pastures on botanical composition

“…This observation is consistent with the fertilizer effect on smooth bromegrass composition at the other four sites. This shift was observed also in second and third year after application of the fertilizer, suggesting a residual effect of fertilizer on botanical composition but not crude protein (Lardner et al 2000). This residual effect was not observed however, in the yield data (Lardner et al 2000) from this site.…”

“…This shift was observed also in second and third year after application of the fertilizer, suggesting a residual effect of fertilizer on botanical composition but not crude protein (Lardner et al 2000). This residual effect was not observed however, in the yield data (Lardner et al 2000) from this site. In the granular fertilizer (C+F) plots, smooth bromegrass increased and Kentucky bluegrass decreased in composition compared to control in all 3 yr, but not always significantly (P > 0.05).…”

Rejuvenation affects nutritive value of long-established tame forages

“…Manipulation of forage species with herbicides and fertilizer methods has affected forage nutritive value and animal performance (Haferkamp et al 1993;Berg and Sims 1995). Carryover effects from fertilization on forage quality (Lardner et al 2000) or burning on legume composition (Lardner et al 2001) need to be examined further. Therefore, studies were conducted to determine animal responses to changes in forage nutritive value as a result of three methods of rejuvenation.…”