Evaluating alfalfa cultivars and germplasms for pastures using the mob-grazing technique

1994 ◽  
Vol 74 (1) ◽  
pp. 109-114 ◽  
Author(s):  
S. Bittman ◽  
D. H. McCartney
Keyword(s):  
Medicago Sativa ◽  
Rest Period ◽  
Grazing Intensity ◽  
Ground Cover ◽  
Smooth Bromegrass ◽  
Grazing Tolerance ◽  
Grazing Intensities ◽  
The Media ◽  
Growth Habits ◽  
Northern Alberta

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.

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
Keyword(s):  
Rest Period ◽  
Grazing Intensity ◽  
Ground Cover ◽  
Grass Species ◽  
Cool Season ◽  
Intermediate Wheatgrass ◽  
Grazing Tolerance ◽  
Elytrigia Repens ◽  
Grazing Intensities ◽  
Meadow Bromegrass

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

An evaluation of lucerne for persistence under grazing in New Zealand

2014 ◽  
Vol 76 ◽  
pp. 111-116 ◽  
Author(s):  
B.M. Harvey ◽  
K.H. Widdup ◽  
B.A. Barrett
Keyword(s):  
New Zealand ◽  
Medicago Sativa ◽  
Low Frequency ◽  
Ground Cover ◽  
Plant Survival ◽  
Grazing Tolerance ◽  
Feed Production ◽  
Heavy Grazing ◽  
Fall Dormancy ◽  
On Farm

Abstract The on-farm use of lucerne (Medicago sativa) for grazing and conserved feed has increased in New Zealand over recent years, with new cultivars coming onto the market, including more winter-active ones. The extent to which the winter active types contribute to annual feed production, and the relationship to critical traits like persistence, has not been systematically tested. Two concurrent trials over a 4-year period were used to evaluate a range of lucerne cultivars and elite experimental populations ranging in dormancy from 2 (highly dormant) to 10 (non-dormant) under contrasting grazing regimes near Lincoln, New Zealand. More winter-active cultivars in the higher fall dormancy (FD) classes had similar growth to lower FD classes in all seasons except autumn, where they exhibited 18% greater yield than the lowest FD entry. However, these higher FD populations do not persist as well under heavy grazing, with a reduction in ground cover of up to 90% after four years, compared with only a 25% loss in lower FD classes. There was a negative correlation between FD and persistence measured as plant survival over 4 years (R2=0.73). However, one high FD entry showed increased survival under grazing, suggesting there is scope for selection of types with improved cool season growth and grazing tolerance. The concurrent lucerne trial subjected to a low-frequency grazing/ cutting regime showed faster recovery from defoliation than the adjacent hard grazed regime, suggesting stored underground reserves were more available for regrowth. We concluded that lucerne cultivars with FD ratings in the 3 to 5 range are most suitable for yield and persistence under grazing in these conditions. There is also scope for breeding to improve plant survival and dry matter yield within FD class. Keywords: Lucerne (Medicago sativa), grazing tolerance, persistence, fall dormancy

scholarly journals Persistence of Grazing Tolerant Lucernes under Australian Conditions

2011 ◽  
Vol 15 ◽  
pp. 187-190
Author(s):  
J.C. Sewell ◽  
R.D. Hill ◽  
J. Reich
Keyword(s):  
Field Experiment ◽  
Medicago Sativa ◽  
Ground Cover ◽  
Late Spring ◽  
Stocking Rate ◽  
Rotational Grazing ◽  
Grazing Tolerance ◽  
Winter Activity ◽  
Grazing Period ◽  
Better Than

Recent experiments have demonstrated that lucerne (Medicago sativa) varieties selected for grazing tolerance will persist far better when grazed for extended periods than varieties not selected for grazing tolerance. A field experiment, with lucerne varieties representing a range of winter activity ratings, was conducted at Ballarat. After 2.5 years of rotational grazing the experiment was continuously grazed for 173 days from late spring to early autumn at a stocking rate equivalent to 50 sheep/ha. This intensity is not considered much higher than some farmers would adopt during a drought. Ground cover of some varieties had significantly declined by the end of the grazing period but further decline occurred throughout the following winter months while livestock were excluded. The grazing tolerant lines persisted better than most standards, even those within the same dormancy category, with some standards almost completely dead while the grazing tolerant lines were over 60% alive. Keywords: grazing tolerance, lucerne (Medicago sativa), persistence

Runoff and sediment yield from snowmelt and rainfall as influenced by forage type and grazing intensity

1998 ◽  
Vol 78 (4) ◽  
pp. 699-706 ◽  
Author(s):  
S. I. Gill ◽  
M. A. Naeth ◽  
D. S. Chanasyk ◽  
V. S. Baron
Keyword(s):  
Sediment Yield ◽  
Environmental Sustainability ◽  
Grazing Intensity ◽  
Annual Runoff ◽  
Rainfall Simulation ◽  
Sediment Yields ◽  
Natural Rainfall ◽  
Grazing Intensities ◽  
Grazing Systems ◽  
Runoff And Sediment Yield

Currently, there is interest in Western Canada in extending the grazing season using perennial and annual forages. Of greatest concern is the environmental sustainability of these grazing systems, with emphasis on their ability to withstand erosion. A study to examine the runoff and sediment yields of annual and perennial forages in central Alberta was initiated in 1994. Runoff and sediment yield were quantified under snowmelt and rainfall events for two seasons. Rainfall simulation was used to further examine runoff under growing season conditions. Four forage treatments (two annuals: triticale and a barley/triticale mixture and two perennials: smooth bromegrass and meadow bromegrass) and three grazing intensities (light, medium and heavy) were studied, each replicated four times. Total annual runoff was dominated by snowmelt. Generally runoff volumes, sediment yields, sediment ratios and runoff coefficients were all low. Bare ground increased with increasing grazing intensity and was significantly greater in annuals than perennials for all grazing intensities. Litter biomass decreased with increasing grazing intensity and was generally similar in all species for both years at heavy and medium grazing intensities. Results from the rainfall simulation corroborated those under natural rainfall conditions and generally indicated the sustainability of these grazing systems at this site. Key words: Forages, soil erosion, sustainability, rainfall simulation

NITROGENASE ACTIVITY OF ALFALFA GROWN ALONE AND IN MIXTURE WITH GRASS UNDER GREENHOUSE CONDITIONS

1985 ◽  
Vol 65 (3) ◽  
pp. 787-791
Author(s):  
H. A. BURITY ◽  
B. E. COULMAN ◽  
M. A. FARIS
Keyword(s):  
Medicago Sativa ◽  
Nitrogenase Activity ◽  
Dactylis Glomerata ◽  
Phleum Pratense ◽  
Bromus Inermis ◽  
Smooth Bromegrass ◽  
Medicago Sativa L ◽  
Dactylis Glomerata L ◽  
Phleum Pratense L ◽  
Nodule Tissue

A greenhouse experiment has shown that total nitrogenase activity of alfalfa (Medicago sativa L.) is not significantly affected when grown in association with timothy (Phleum pratense L.), smooth bromegrass (Bromus inermis Leyss) or orchardgrass (Dactylis glomerata L.) except after initial harvest when decreased alfalfa activity was associated with smooth bromegrass or orchardgrass. It was concluded that mixed cultures of alfalfa with timothy, smooth bromegrass or orchardgrass have no effect on alfalfa N2 fixation. The results also suggest the occurrence of N transference from alfalfa to associated grasses. It is speculated that this transfer is not primarily due to the death of roots and nodule tissue (after harvest), but involves some degree of N excretion during the period before initial harvest.Key words: Alfalfa-grass mixtures, N2-fixation, nodule activity, N-transference

Water potentials of seeds of Bromus inermis and Medicago sativa imbibed on media of various osmotic potentials

1976 ◽  
Vol 54 (17) ◽  
pp. 1997-1999 ◽  
Author(s):  
W. T. McDonough
Keyword(s):  
Polyethylene Glycol ◽  
Medicago Sativa ◽  
Bromus Inermis ◽  
Smooth Brome ◽  
Thermocouple Psychrometer ◽  
Water Potentials ◽  
The Media ◽  
Medicago Sativa L ◽  
Brome Grass ◽  
Osmotic Potentials

Seeds of smooth brome grass (Bromus inermis Leyss.) and alfalfa (Medicago sativa L. cultivar Ladak) were allowed to imbibe in water or solutions of polyethylene glycol (Carbowax 1540), mannitol, or sodium chloride. Seed water potentials were determined over a 72-h period after transfer of seeds to thermocouple psychrometer chambers. Seed water potentials were lower than osmotic potentials of the media, but these two potentials were not clearly related to each other. Possible reasons for the lack of gradation in response are discussed.

scholarly journals Soil bulk electrical resistivity and forage ground cover: nonlinear models in an alfalfa (Medicago sativa L.) case study

2015 ◽  
Vol 10 (4) ◽  
pp. 215 ◽  
Author(s):  
Roberta Rossi ◽  
Alessio Pollice ◽  
Gianfranco Bitella ◽  
Rocco Bochicchio ◽  
Amedeo D'Antonio ◽  
...  
Keyword(s):  
Electrical Resistivity ◽  
Medicago Sativa ◽  
Vegetation Index ◽  
Nonlinear Models ◽  
Ground Cover ◽  
Plant Productivity ◽  
Additive Models ◽  
Deep Soil ◽  
Soil Features ◽  
Normalised Difference Vegetation Index

Alfalfa is a highly productive and fertility-building forage crop; its performance, can be highly variable as influenced by within-field soil spatial variability. Characterising the relations between soil and forage- variation is important for optimal management. The aim of this work was to model the relationship between soil electrical resistivity (ER) and plant productivity in an alfalfa (<em>Medicago sativa</em> L.) field in Southern Italy. ER mapping was accomplished by a multi-depth automatic resistivity profiler. Plant productivity was assessed through normalised difference vegetation index (NDVI) at 2 dates. A non-linear relationship between NDVI and deep soil ER was modelled within the framework of generalised additive models. The best model explained 70% of the total variability. Soil profiles at six locations selected along a gradient of ER showed differences related to texture (ranging from clay to sandy-clay loam), gravel content (0 to 55%) and to the presence of a petrocalcic horizon. Our results prove that multi-depth ER can be used to localise permanent soil features that drive plant productivity.

scholarly journals Transcriptome-wide gene expression plasticity in Stipa grandis in response to grazing intensity differences

2020 ◽  
Author(s):  
Zhenhua Dang ◽  
Yuanyuan Jia ◽  
Yunyun Tian ◽  
Jiabin Li ◽  
Yanan Zhang ◽  
...  
Keyword(s):  
Gene Expression ◽  
Metabolic Pathways ◽  
Molecular Mechanisms ◽  
Expression Profiles ◽  
Gene Expression Profiles ◽  
Grazing Intensity ◽  
Glycolate Oxidase ◽  
Bisphosphate Carboxylase ◽  
Grazing Intensities

Organisms have evolved effective and distinct adaptive strategies to survive. Stipa grandis is one of the widespread dominant species on the typical steppe of the Inner Mongolian Plateau, and is regarded as a suitable species for studying the effects of grazing in this region. Although phenotypic (morphological and physiological) variations in S. grandis in response to long-term grazing have been identified, the molecular mechanisms underlying adaptations and plastic responses remain largely unknown. Accordingly, we performed a transcriptomic analysis to investigate changes in gene expression of S. grandis under four different grazing intensities. A total of 2,357 differentially expressed genes (DEGs) were identified among the tested grazing intensities, suggesting long-term grazing resulted in gene expression plasticity that affected diverse biological processes and metabolic pathways in S. grandis. DEGs were identified that indicated modulation of Calvin–Benson cycle and photorespiration metabolic pathways. The key gene´expression profiles encoding various proteins (e.g., Ribulose-1,5-bisphosphate carboxylase/oxygenase, fructose-1,6-bisphosphate aldolase, glycolate oxidase etc.) involved in these pathways suggest that they may synergistically respond to grazing to increase the resilience and stress tolerance of S. grandis. Our findings provide scientific clues for improving grassland use and protection, and identify important questions to address in future transcriptome studies.

scholarly journals Grazing and Cultivated Grasslands Cause Different Spatial Redistributions of Soil Particles

2019 ◽  
Vol 16 (15) ◽  
pp. 2639 ◽  
Author(s):  
Jinsheng Li ◽  
Jianying Shang ◽  
Ding Huang ◽  
Shiming Tang ◽  
Tianci Zhao ◽  
...  
Keyword(s):  
Soil Layer ◽  
Soil Health ◽  
Grazing Intensity ◽  
Health Condition ◽  
Soil Particle ◽  
Particle Sizes ◽  
Soil Layers ◽  
Soil Particles ◽  
Heavy Grazing ◽  
Grazing Intensities

The distribution of soil particle sizes is closely related to soil health condition. In this study, grasslands under different grazing intensities and different cultivation ages grasslands were selected to evaluate the dynamics of soil particle size redistribution in different soil layers. When the grazing intensity increased, the percentage of 2000~150-μm soil particles in the 0–10-cm soil layer decreased; 150~53-μm soil particles remained relatively stable among the grazing intensities—approximately 28.52%~35.39%. However, the percentage of less than 53-μm soil particles increased. In cultivated grasslands, the larger sizes (>53 μm) of soil particles increased and the smaller sizes (<53 μm) decreased significantly (p < 0.05) in the 0–10 cm-soil layer with increasing cultivation ages. The increase in small soil particles (<53 μm) in topsoil associated with grazing intensity increased the potential risk of further degradation by wind erosion. The increase in big soil particles (>53 μm) in topsoil associated with cultivation ages decreased the soil capacity of holding water and nutrient. Therefore, to maintain the sustainability of grassland uses, grazing grasslands need to avoid heavy grazing, and cultivated grasslands need to change current cultivation practices.

scholarly journals Soil Properties and Plant Community Changes along a Goat Grazing Intensity Gradient in an Open Canopy Oak Forest

2013 ◽  
Vol 41 (2) ◽  
pp. 567 ◽  
Author(s):  
Aimilia LEMPESI ◽  
Apostolos P. KYRIAZOPOULOS ◽  
Michail ORFANOUDAKIS ◽  
Georgios KORAKIS
Keyword(s):  
Soil Properties ◽  
Plant Community ◽  
Management Practices ◽  
Plant Cover ◽  
Grazing Intensity ◽  
Oak Forest ◽  
Goat Grazing ◽  
Open Canopy ◽  
Grazing Intensities ◽  
Soil Measurements

Understanding how the management practices of silvopastoral systems affect the long-term sustainability of oak ecosystems and what their influence is on nutrient cycling and plant community, is of great interest. The aim of this study was to examine the effects of relative grazing intensity on soil properties and on vegetation characteristics in an open canopy oak forest dominated by Quercus frainetto. The research was conducted in the area of Pentalofos, which is located in Evros region, north-eastern Greece and is grazed by goats. The distance from a goat corral was used to represent relative grazing intensity. In June 2011, soil and vegetation samples were collected along transects placed at 50, 150, 300, 600 and 1200 m from the goat corral, running perpendicular to three replicates. Soil measurements included pH, phosphorous (P) and nitrogen (N) concentrations while vegetation measurements included plant cover, species composition and diversity. Plant cover was not significantly different among grazing intensities. Species diversity, especially of the woody vegetation layer, was significantly higher in the light grazing intensity in comparison to both the heavy and the very light grazing. Heavy grazing reduced soil organic matter while it increased total nitrogen. Grazing intensity did not affect available P and soil pH. Light to moderate goat grazing could ameliorate floristic diversity and increase sustainability of oak forests in the Mediterranean region.

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