Persistence of cool-season grasses under grazing using the mob-grazing technique

1994 ◽  
Vol 74 (4) ◽  
pp. 723-728 ◽  
Author(s):  
D. H. McCartney ◽  
S. Bittman

Evaluation of grass germplasms for pasture is usually done in trials which are harvested mechanically. This study evaluated the persistence of 13 cool-season grass species and germplasms under 4 yr of grazing in northeast Saskatchewan, using the mob-grazing technique. Thirteen grass germplasms were contained within each paddock, and the paddocks were grazed by large groups of cattle so that all the herbage was consumed evenly in 1–2 d. Three grazing intensities (light, moderate and intense) were established by varying the rest period between grazings. Ground cover declined more rapidly under intense than under light grazing, but no interaction was found between grazing intensity and grass germplasm. The ground cover of the seeded grasses generally declined but at different rates during the trial, giving a significant grass × year interaction. Parkway crested wheatgrass [Agropyron cristatum (L.) Beauv. ssp. pectination (Bieb.) Tzvel.] declined less than Carlton smooth bromegrass (Bromus inermis Leyss.) and the meadow bromegrass (Bromus biebersteinii Roem & Schult.) cultivars. The most rapid stand decline was observed in intermediate wheatgrass [Elytrigia intermedia (Host) Nevski], northern wheatgrass (Elymus lanceoiatus Scribn. & Smith), and hybrid wheatgrass [Elytrigia repens (L.) Nevski × E. spicata (Pursh) D. R. Dewey]. Seeded grasses were replaced mainly by bluegrass (Poa spp.). The results suggest that mob grazing is a useful technique for evaluating new species and germplasms intended for long-term pastures. Key words: Grazing tolerance, temperate grasses, pasture, ground cover, bromegrass, wheatgrass, wildrye, bluegrass

1994 ◽  
Vol 74 (1) ◽  
pp. 109-114 ◽  
Author(s):  
S. Bittman ◽  
D. H. McCartney

There is growing evidence that alfalfa (Medicago sativa L. sensu lato) germplasms that perform well in trials that are mechanically clipped may not persist well under grazing. This trial assessed the persistence of nine alfalfa germplasms under grazing over a period of 4 yr in northeast Saskatchewan. The germplasms included registered cultivars and experimental strains of M. sativa ssp. media Pers. and M. sativa ssp. falcata (L.) Arcang. with a range of growth habits and winterhardiness. Each paddock was seeded with all entries in mixture with smooth bromegrass (Bromus inermis Leyss.) and grazed repeatedly for 1- to 2-d periods, using high stocking rates, to ensure that all entries were grazed uniformly. Three grazing intensities — light, moderate and intense — were set by varying the rest period between grazings. Ground cover of all the currently recommended alfalfa cultivars of the media ssp. declined during the trial; the germplasms of falcata ssp. increased; and two media ssp. strains from northern Alberta maintained fairly constant ground cover. Grazing intensity affected rate of stand decline but not final ranking of germplasms, so there was no grazing × germplasm interaction. Seeded and volunteer smooth bromegrass maintained better stands under light than intense grazing, whereas volunteer bluegrass (Poa spp.) performed better under intense grazing. Ground cover of alfalfa germplasms was generally correlated with their annual yield and proportion of total dry matter yield. The results suggest that falcata germplasms should be included in seed mixes for long-term pastures and that mob grazing be used to assess the persistence of alfalfa germplasms before they are recommended for use in pastures. Key words:Medicago sativa L., Medicago sativa ssp. falcata (L.) Arcang., persistence, grazing tolerance.


2011 ◽  
Vol 29 (2) ◽  
pp. 75-80
Author(s):  
Thomas Serensits ◽  
Matthew Cutulle ◽  
Jeffrey F. Derr

Abstract Cool-season grass species are often overseeded into bermudagrass turf for both aesthetics and functionality during the winter months. When the overseeded grass persists beyond the spring, however, it becomes a weed. Experiments were conducted to evaluate overseeded grass species and seeding rate on turf cover during the fall, spring, and summer. The ability of perennial ryegrass, Italian ryegrass, and hybrid bluegrass to then persist in bermudagrass one year after seeding was determined. Both perennial ryegrass and Italian ryegrass produced acceptable ground cover in the spring after fall seeding. Hybrid bluegrass did not establish well, resulting in unacceptable cover. Perennial ryegrass generally had the most persistence one year after seeding, either because of the survival of plants through the summer or because of new germination the following fall. The highest cover seen one year after seeding was 24% with perennial ryegrass in the 2005 trial. Maximum cover seen with Italian ryegrass and hybrid bluegrass 12 months after seeding was 19 and 8%, respectively. Seeding perennial or Italian ryegrass in February achieved acceptable cover in spring in the first trial but not the second. Persistence the following fall, however, was greater in the second trial, suggesting new germination. Percent cover 12 months after seeding tended to increase as the seeding rate increased, also suggesting new germination the following fall. Although quality is lower with Italian ryegrass compared to perennial ryegrass, it transitions out easier than perennial ryegrass, resulting in fewer surviving plants one year after fall seeding.


1999 ◽  
Vol 79 (1) ◽  
pp. 83-89 ◽  
Author(s):  
N. W. Holt ◽  
P. G. Jefferson

Forage grasses need to be evaluated in pasture trials in the Great Plains region of North America. The objective of this study was to compare four grass–alfalfa (Medicago sativa L.) mixtures for productivity and persistence when grazed during spring and summer. The grasses were Altai wildrye (Leymus angustus [Trin.] Pilger), intermediate wheatgrass (Elytrigia intermedia [Host] Nevski), meadow bromegrass (Bromus riparius Rehm. syn. B. biebersteinii Roem. & Schult.) and Russian wildrye (Psathyrostachys junceus [Fisch.] Nevski), with grass rows seeded perpendicular to the alfalfa rows. Two sites, 4 km apart, were grazed with yearling beef cattle from 1987 to 1993. Forage yield differed among grass treatments in 4 of 5 years, but differences were inconsistent over time. Five-year mean forage yields and total livestock production were not significantly different among the four grasses. Mean annual forage yields ranged from 800 to 8170 kg ha−1 and were related to the amount of growing season (April–August) precipitation. Carrying capacity ranged from 35 steer grazing days per hectare in 1992 to 176 in 1991. Grasses in the mixtures did have a significant effect on the grass–alfalfa ratio and on ground cover. Alfalfa content was highest when grown with Altai wildrye and lowest when grown with Russian wildrye. Percentage of ground cover by the grass plus alfalfa increased from an average of 3.8% in 1987 to 16.1% at one site and 31.9% at the second site by 1993. Russian wildrye contained the least alfalfa and weeds after 7 yr. Intermediate wheatgrass and Altai wildrye did not compete with invading weeds at one site, or with alfalfa at the other, and should not be recommended for spring–summer pastures in semiarid regions. Meadow bromegrass maintained a balance of grass and alfalfa and further research should confirm its persistence in semiarid climates. Key words: Leymus angustus, Elytrigia intermedia, Bromus riparius, Psathyrostachys junceus, Medicago sativa, grazing with cattle


2002 ◽  
Vol 82 (4) ◽  
pp. 747-750 ◽  
Author(s):  
H. A. Lardner ◽  
S. B. M. Wright ◽  
R. D. H. Cohen

Grazing by herbivores affects grass species both morphologically and physiologically. A study was conducted on an irrigated pasture near Outlook, Saskatchewan, Canada during the summer of 1991 to determine leaf regrowth after grazing of reed canarygrass (Phalaris arundinacea L.), slender wheatgrass [Elymus trachycaulus (Link) Gould ex Shinners subsp. trachycaulus], intermediate wheatgrass [Thinopyrum intermedium (Host) Barkw. & D.R. Dewey subsp. intermedium], orchardgrass (Dactylis glomerata L.), meadow bromegrass (Bromus beibersteinii Roem. & Schult.), smooth bromegrass (Bromus inermis Leyss.), tall fescue [Festuca arundinacea (Schreb.) Wimm.] and timothy (Phleum pratense L.) in order to evaluate the suitability of these species for grazing. All eight species were mob-grazed by sheep at a stocking density of 30 animals ha-1. Physiological stage of leaf development was determined at 7, 14 and 21 d following defoliation. Smooth bromegrass and timothy consistently produced the greatest number of leaves for all regrowth periods. Tall fescue produced the least number of leaves at all time periods. Fifty-five percent of slender wheatgrass tillers and 19% of intermediate wheatgrass tillers were reproductive 21 d after defoliation. Based on leaf regrowth after grazing measured by leaf appearance, the grasses were ranked into three groupings – meadow bromegrass, smooth bromegrass and reed canarygrass ranked highest; intermediate wheatgrass, slender wheatgrass and orchardgrass ranked intermediate; and timothy and tall fescue ranked lowest. Key words: Leaf, regrowth, grass, grazing


2016 ◽  
Vol 9 (2) ◽  
pp. 87-95 ◽  
Author(s):  
Katie L. Wirt ◽  
Rodney G. Lym

When invasive weeds are removed with herbicides, revegetation of native species is often desirable. The extended soil activity of aminocyclopyrachlor is important for long-term weed control but could reduce recovery of native species as well. The effect of aminocyclopyrachlor applied alone or with chlorsulfuron on cool- and warm-season grass species commonly used for revegetation was evaluated. The cool-season grasses included green needlegrass, intermediate wheatgrass, and western wheatgrass, whereas the warm-season grasses were big bluestem, sideoats grama, and switchgrass. A separate experiment was conducted for each species. Aminocyclopyrachlor was applied at 91 to 329 g ha−1 alone or with chlorsulfuron from 42 to 133 g ha−1 approximately 30 d after emergence. Warm-season grasses generally were more tolerant of aminocyclopyrachlor than the cool-season grasses evaluated in this study. Switchgrass and big bluestem were the most tolerant of the warm-season species when aminocyclopyrachlor was applied at 168 g ha−1 and averaged 199 and 150% forage production, respectively, compared with the control. Green needlegrass was the most tolerant cool-season grass. Western wheatgrass was the least tolerant species evaluated because forage production only averaged 32% of the control the year after treatment and thus would not be suitable for seeding if aminocyclopyrachlor was applied. The effect of chlorsulfuron applied with aminocyclopyrachlor varied by grass species. For example, green needlegrass injury 8 wk after treatment (WAT) averaged 30 and 48% when aminocylopyrachlor was applied alone, respectively, but injury was reduced to less than 16% when aminocyclopyrachlor was applied with chlorsulfuron. However, injury on the less-tolerant intermediate wheatgrass ranged from 48 to 92% by 4 WAT when aminocyclopyrachlor was applied alone and from 60 to 86% when chlorsulfuron was included in the treatment.


2003 ◽  
Vol 83 (3) ◽  
pp. 551-554 ◽  
Author(s):  
H. A. Lardner ◽  
S. B. M. Wright ◽  
R. D. H. Cohen

Grazing by herbivores can affect root carbohydrate reserves of grass species. A grazing study was conducted on an irrigated pasture near Outlook, Saskatchewan, Canada, during the summers of 1991 and 1992 t o determine etiolated regrowth after grazing of reed canarygrass ( Phalaris arundinacea L.), slender wheatgrass ( Elymus trachycaulus (Link) Gould ex Shinners subsp . trachycaulus), intermediate wheatgrass [ Thinopyrum intermedium (Host) Barkw. & D.R. Dewey subsp . intermedium], orchardgrass ( Dactylis glomerata L.), meadow bromegrass ( Bromus biebersteinii Roem. & Schult.), smooth bromegrass ( Bromus inermis Leyss.), tall fescue [ Festuca arundinacea (Schreb.) Wimm.] and timothy ( Phleum pratense L.) in order to eva luate the suitability of these species for grazing. All eight species were mob-grazed by sheep at a stocking rate of 30 animals ha-1. Carbohydrate reserves were estimated by determination of etiolated regrowth. Meadow bromegrass produced the greatest etiol ated regrowth and timothy the least. Based on production of etiolated regrowth the grasses were ranked into three groups - meadow bromegrass and intermediate wheatgrass ranked highest, smooth bromegrass, reed canarygrass, slender wheatgrass and orchardgra ss ranked intermediate and timothy and tall fescue ranked lowest. Key words:


2011 ◽  
Vol 2011 ◽  
pp. 1-8
Author(s):  
Thomas Serensits ◽  
Matthew Cutulle ◽  
Jeffrey F. Derr

Cool-season grass species are commonly overseeded into bermudagrass turf for winter color. When the overseeded grass persists beyond the spring; however, it becomes a weed. The ability of perennial ryegrass, Italian (annual) ryegrass, intermediate ryegrass, and hybrid bluegrass to persist in bermudagrass one year after seeding was determined. Perennial ryegrass, intermediate ryegrass, and Italian ryegrass produced acceptable ground cover in the spring after fall seeding. Hybrid bluegrass did not establish well, resulting in unacceptable cover. Perennial ryegrass generally persisted the most one year after seeding, either because of summer survival of plants or because of new germination the following fall. Plant counts one year after seeding were greater in the higher seeding rate treatment compared to the lower seeding treatment rate of perennial ryegrass, suggesting new germination had occurred. Plant counts one year after seeding plots with intermediate ryegrass or Italian ryegrass were attributed primarily to latent germination and not summer survival. Applications of foramsulfuron generally did not prevent overseeded species stand one year after seeding, supporting the conclusion of new germination. Although quality is less with intermediate ryegrass compared to perennial ryegrass, it transitions out easier than perennial ryegrass, resulting in fewer surviving plants one year later.


1978 ◽  
Vol 1 (2) ◽  
pp. 174 ◽  
Author(s):  
RDB Whalley ◽  
GG Robinson ◽  
JA Taylor

Three major pasture types probably occurred on the Northern Tablelands prior to European settlement. The dominants were probably Poa sieberana Spreng. and Themeda australis (R.Br.1 Stapf. at the higher elevations, T. australis, P. Sieberana and Sorghum leiocladum (Hack.) C.E. Hubbard on fine textured soils at lower elevations and T. australis, Aristida ramosa (R.Br.) and Cymbopogon refractus (R.Br.1 A. Camus. on coarse textured soils. The subsidiary species composition of these pasture types is also suggested, derived from fragmentary early accounts, earlier published work and observations on the behaviour under grazing of the different species involved. The characteristics of the important native and naturalised grass species are described. These species are classified into warm season perennials, warm season annuals, cool season perennials and cool season annuals. The native warm season perennials is the largest group of species at present on the Tablelands. The effects of grazing on the species composition of natural pastures is described. The grazing behaviour of merino sheep leads to a striking zonation of herbaceous species resulting from uneven grazing intensity and distribution of dung and urine. Data from an unreplicated stocking rate by superphosphate application rate trial at Shannon Vale are presented. This trial indicated that the proportion of white clover in the pasture depended on both stocking rate and superphosphate rate and that the proportion of Danthonia spp. increased when white clover decreased. Wool production data are also presented which show that high levels of pro- ductivity per hectare can be obtained from topdressed natural pastures. A number of different natural pasture types occur on the Tablelands. A schemeis presented showing the interrelationship$ between the original and the present pasture types as affected by grazing intensity and the addition or depletion of plant nutrients.


1987 ◽  
Vol 67 (3) ◽  
pp. 719-725 ◽  
Author(s):  
R. P. KNOWLES

Six Eurasian temperate zone grasses, one mixture of these, and three North American wheatgrasses were compared in mainly nonfertilized tests from 1974 to 1983 in Saskatchewan, Canada. Introduced grasses outyielded natives at Saskatoon when cut once per season as hay with the following declining yield order (kg/ha): intermediate wheatgrass (3819), standard crested wheatgrass (2906), smooth bromegrass (2841), Russian wild ryegrass (2311), Fairway crested wheatgrass (2218), meadow bromegrass (2082), slender wheatgrass (2011), western wheatgrass (1919), and northern wheatgrass (1683). Much the same order of yield was observed when these grasses were clipped two to three times per season, although meadow bromegrass and western wheatgrass performed relatively better. At the Scott site, standard crested wheatgrass and northern wheatgrass performed relatively better than at Saskatoon. Slightly lower in vitro digestibility ratings were shown for natives than for introduced species and this appeared to be due to the more rapid senescence of natives. Stands at Saskatoon were maintained for 10 yr for all species except slender wheatgrass which lasted 5 yr. Weed control was best for meadow bromegrass and smooth bromegrass and poorest for slender wheatgrass, northern wheatgrass, and Fairway crested wheatgrass. Fertilizer applied to older stands showed a greater response for introduced grasses than for natives.Key words: Grass species, productivity, hay, pasture, longevity


Crop Science ◽  
2002 ◽  
Vol 42 (3) ◽  
pp. 890 ◽  
Author(s):  
Blair L. Waldron ◽  
Kay H. Asay ◽  
Kevin B. Jensen

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