Species dynamic, forage yield, and nutritive value of seeded native plant mixtures following grazing

Abstract

Schellenberg, M. P, Biligetu, B. and Iwaasa, A. D. 2012. Species dynamic, forage yield, and nutritive value of seeded native plant mixtures following grazing. Can. J. Plant Sci. 92: 699–706. There is increasing interest in native plants of North America for rangeland reseeding in the semiarid regions of western Canada. However, there is limited information available on forage yield, nutritive value and response to grazing of seeded native plant mixture. The objective of this study was to compare foliar cover, forage yield, and nutritive value of two different native plant mixtures under grazing. In 2001–2004, a study was initiated on Orthic Brown Chernozemic (Aridic Haploboroll) soil near Swift Current (lat. 50°25'N, long. 107°44'W), Canada. The experimental design was a randomized complete block with a full factorial arrangement of seed mixtures (7 species and 14 species) and stocking rates (1.3 and 2.7 animal units ha−1) with four replications of each treatment combination. The 7-species mixture produced more forage than the 14-species mixture in July, August, and September of all study years. The 7-species mixture, however, had lower crude protein than the 14-species mixture in August and September in 2002 and 2003. Neutral detergent fiber and acid detergent fiber concentrations were generally similar between the two mixtures for July, August, and September sampling for all 3 yr. Foliar cover of awned wheatgrass [(Elymus trachycaulus (Link) Gould & Shin. ssp subsecundus (Link) A. & D. Love.] and slender wheatgrass [Elymus trachycaulus (Link) Gould subsp. trachycaulus] was higher in the 7-species mixture than the 14-species mixture, but foliar cover of other species was similar between the two mixtures. Shrub species were rarely observed in the stand at any year. Higher stocking rate decreased foliar cover of slender wheatgrass and weeds, but foliar cover of other species was similar between the two stocking rates. Based on the results, a seed mixture of native cool-season grasses may be more productive than a combination of native warm- and cool-season grasses under semiarid region of western Canada, but inclusion of warm-season grasses could improve nutritive value by increasing protein content in the late summer months.

Contribution of Medicago sativa to the productivity and nutritive value of forage in semi‐arid grassland pastures

“…This warm-season grass may then contribute to increasing the nutritive value of forage during the hottest periods of summer, when M. sativa was present. This result is in agreement with Schellenberg et al (2012), who showed that the inclusion of warm-season grasses in a mixture containing cool-season grasses can enhance the nutritive value of forage by increasing its protein content during late summer periods in semi-arid regions. The warmseason grass (B. gracilis) also had a higher P concentration in its tissues, when soil P was high.…”

“…Over time, raising cattle on pastures seeded with native grasses is sustainable and encroaches less upon neighbouring native prairies than do introduced species (Jefferson et al, 2004). Recently, several studies have indicated that seeding native species in wellmanaged systems can produce large amounts of high-quality forage for livestock grazing early, but also late, in the growing season (Jefferson et al, 2002;Schellenberg, Biligetu, & Iwaasa, 2012), as opposed to introduced species which are dormant under the dry conditions of mid-summer (Knowles, 1987). In addition, forage grasses tend to be more productive in mixture than as monocultures (Schellenberg, 2008;Tilman et al, 2001), especially when the mixtures contain both warm-and cool-season grasses.…”

Condensed tannins concentration of selected prairie legume forages as affected by phenological stages during two consecutive growth seasons in western Canada

“…Research found that grazing disturbance is a benefit in maintaining species diversity in re-established native grass stands and seeded native plants produced relatively stable forage under grazing over the four years 34,36 . Native grasslands have evolved under grazing and grazing can stimulate above ground production by increasing tillering and rhizome production 32 .…”

High precipitation and seeded species competition reduce seeded shrub establishment during dryland restoration

“…Of the three major plant groups comprising dryland plant communities (grasses, forbs, shrubs), restoration of shrubs has proven most failure prone. When sown with grasses, shrubs often nearly or completely fail to establish (e.g., Bailey et al 2010, Fansler and Mangold 2011, Kulpa et al 2012, Schellenberg et al 2012. Consequently, ''restored'' drylands often have adequate grass stands but no shrubs or far fewer shrubs than nearby reference sites (Booth et al 1999, Simmers and Galatowitsch 2010, Frouz et al 2013.…”