Germination characteristics of several grass species as affected by limiting water potentials imposed through a cracking black clay soil

The effects of limiting water potentials on the germination characteristics of 12 grasses were studied. Germination proper was prevented in all species at water potentials well short of wilting point and different species had their germination prevented at different potentials. Generally the native grasses required wetter conditions to germinate than the exotic grasses, although there were some exceptions. A partial germination condition, caused by limited water availability, occurred to differing degrees amongst the species. Some species retained their viability when desiccated in the partially germinated condition, but other species lost their viability. The partial germination phenomenon appears important to the germination ecology of some species but not to others.

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Establishment of native and exotic grasses on mine overburden and topsoil in the Hunter Valley, New South Wales

The Rangeland Journal ◽

10.1071/rj05006 ◽

2005 ◽

Vol 27 (2) ◽

pp. 73 ◽

Cited By ~ 12

Author(s):

C. H. A. Huxtable ◽

T. B. Koen ◽

D. Waterhouse

Keyword(s):

Seed Bank ◽

Native Species ◽

Soil Seed Bank ◽

Coal Mines ◽

Climatic Conditions ◽

Perennial Grasses ◽

Grass Species ◽

Native Grasses ◽

Exotic Grasses ◽

Mine Rehabilitation

Native grasses have an important role to play in mine rehabilitation throughout Australia, but there have been few scientifically designed studies of field establishment of native grasses from sown seed in this country. Current recommendations for rehabilitation of open-cut coal mines in the Hunter Valley involve the sowing of exotic pasture species to reinstate mined land to Class IV and V under the Rural Land Capability System. Despite the importance of native grasses in the pre-mined landscape, they are currently not widely included in mine rehabilitation. To address this issue a project was conducted between 1994 and 2000 to research the use of native grasses for rehabilitation of open-cut coal mines in the Hunter Valley. This paper reports on 2 mine site experiments that aimed to assess establishment and persistence of a broad range of native and exotic grass species from an autumn sowing in both topsoil and raw spoil over a period of 61 months. The most promising natives in terms of early establishment, persistence and spread over time, included six C3 accessions (five Austrodanthonia spp. and Austrostipa bigeniculata) and one C4 accession (Cynodon dactylon). Persistence of these accessions was better in raw spoil than topsoil, despite initial low numbers, due to a lack of weed competition and their ability to spread by self-seeding. In topsoil, and in the absence of any biomass reduction, native species were mostly out-competed by vigorous exotic perennial grasses which were sown in these experiments and from seed influx from adjacent rehabilitation areas or from the soil seed bank. The effects of climatic conditions and differences in soil physical, chemical and seed bank characteristics at the 2 mine sites are also discussed.

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Effect of black clay soil moisture on the electrochemical behavior of API X70 pipeline steel

Materials Research Express ◽

10.1088/2053-1591/aab40e ◽

2018 ◽

Vol 5 (3) ◽

pp. 036523

Author(s):

R Hendi ◽

H Saifi ◽

K Belmokre ◽

M Ouadah ◽

B Smili ◽

...

Keyword(s):

Soil Moisture ◽

Electrochemical Behavior ◽

Clay Soil ◽

Pipeline Steel ◽

X70 Pipeline Steel ◽

Black Clay

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Yield Component Responses of the Brachiaria brizantha Forage Grass to Soil Water Availability in the Brazilian Cerrado

Agriculture ◽

10.3390/agriculture10010013 ◽

2020 ◽

Vol 10 (1) ◽

pp. 13

Author(s):

Camila Thaiana Rueda da Silva ◽

Edna Maria Bonfim-Silva ◽

Tonny José de Araújo da Silva ◽

Everton Alves Rodrigues Pinheiro ◽

Jefferson Vieira José ◽

...

Keyword(s):

Soil Water ◽

Water Availability ◽

Water Pressure ◽

Soil Water Potential ◽

Yield Component ◽

Forage Yield ◽

Soil Water Availability ◽

Grass Species ◽

Forage Production ◽

Brachiaria Brizantha

Brazil is one of the world’s largest producers of beef cattle and dairy products, which requires high forage yield to attend grass-fed animals’ demand. Among the grass species adopted in the forage production system in Brazil, the Brachiaria genus stands out. This genus comprises nearly 85% of all planted forage area. In general, forage production systems in Brazil are essentially rainfed, and thus susceptible to seasonal soil water stresses. Selecting the suitable Brachiaria cultivar for lands susceptible to periodic waterlogging and dry spells is crucial to enhance forage yield, and consequently, to reduce the environmental footprint of the livestock sector. In this research, we investigated the performance of three recent commercial Brachiaria brizantha cultivars (Piatã, BRS Paiaguás, and MG13 Braúna) extensively adopted in Brazil’s grazing systems subjected to different ranges of soil water potential. For three cutting periods, yield related-variables (e.g., plant height, leaf area, dry biomass, and water use efficiency) were measured. Our results point to the existence of a low drought-resistant trait among cultivars, indicating the need for releasing better-adapted cultivars to cope with reduced soil water availability. All cultivars achieved higher performance at soil water pressure head between −15 kPa and −25 kPa; and in general, the cultivar. Piatã showed slightly superior results to most of the treatments.

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Smoke affects the Germination of Native Grasses of New South Wales

Australian Journal of Botany ◽

10.1071/bt97124 ◽

1999 ◽

Vol 47 (4) ◽

pp. 563 ◽

Cited By ~ 32

Author(s):

Tamara R. Read ◽

Sean M. Bellairs

Keyword(s):

New South ◽

Germination Rate ◽

New South Wales ◽

Germination Percentage ◽

Grass Species ◽

Native Grasses ◽

Environmental Stimulus ◽

Native Grass ◽

South Wales ◽

Stimulation Of

The germination responses to plant-derived smoke of seeds of 20 native grass species from New South Wales, Australia, were tested under laboratory conditions. The species belonged to 14 genera including Bothriochloa, Chloris, Cymbopogon, Danthonia, Dichanthium, Digitaria, Eragrostis, Eriochloa, Microlaena, Panicum, Paspalidium, Poa, Stipa and Themeda. The interaction between smoke and husk-imposed dormancy was examined by removing the floral structures surrounding the seeds, when sufficient seeds were available. Smoke was shown to be an important environmental stimulus for breaking the dormancy of native grasses; however, the response differed considerably between different genera and between species of the same genus. For almost half of the species, smoke significantly increased the germination percentage. Panicum decompositum showed the greatest response, with germination increasing from 7.7 to 63.1% when smoke was applied. Panicum effusum had no germination in the absence of smoke, but 16.7% germination when smoke was applied. Stipa scabra subsp. scabra had germination significantly reduced by smoke from 30.2 to 19.9%. Five species had their germination rate, but not the final germination percentage, affected by smoke, and a third of the species were unaffected by smoke. For five of the species, Chloris ventricosa, Dichanthium sericeum, Panicum decompositum, Poa labillardieri and Stipa scabra subsp. falcata, this is the first report of a smoke-stimulated germination response. For those species with germination promoted by smoke, retention of the covering structures did not prevent smoke stimulation of germination. Sowing smoke-treated husked seeds is likely to be preferable as it would still promote greater germination, whereas dehusking seeds can result in the seeds being more susceptible to desiccation and fungal attack in the field. It is suggested that other grassland communities that respond to pyric conditions may also contain species that respond to smoke.

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Plant and animal constraints to voluntary feed intake associated with fibre characteristics and particle breakdown and passage in ruminants

Australian Journal of Agricultural Research ◽

10.1071/ar9960199 ◽

1996 ◽

Vol 47 (2) ◽

pp. 199 ◽

Cited By ~ 88

Author(s):

JR Wilson ◽

PM Kennedy

Keyword(s):

Organic Matter ◽

Dry Matter ◽

Shoot Growth ◽

Surface Soil ◽

Clay Soil ◽

Grass Species ◽

Soil Nitrate ◽

The Sun ◽

N Yield ◽

Organic Matter Breakdown

Effects of artificial shading to 50% sunlight of nitrogen (N) limited tropical pastures of different grass species on a high (clay loam) and low (granitic loam) fertility soil type were evaluated in a semi-arid. subtropical environment over 3 years. The hypothesis was tested that shade can stimulate shoot growth by providing a modified environment more conducive to organic matter breakdown leading to increased mineralisation and availability of soil N, and the ability of tropical grasses to take advantage of this effect was examined. Unfertilised pastures of green panic (Panicum maximum var. trichoglume), buffel (Cenchrus ciliaris). rhodes (Chloris gayana), and speargrass (Heteropogon contortus) in full sun or shaded by sarlon cloth were sampled on 9 occasions. Additional green panic plots on both soils were irrigated for the first 2 years, and all other plots were dependent on natural rainfall. Shoot and root dry matter and N yield, and soil nitrate and ammonia N, were measured. In one set of green panic plots on each soil, canopy. litter, and surface soil temperatures were monitored continuously, and soil moisture at different depths was measured fortnightly. Shade stimulated shoot dry matter yield over the 3 years by up to 37% in green panic. 22% in rhodes, and 9% in speargrass. Shade decreased buffel yield on the clay soil but had no effect on the granitic soil. Relative increases in yield of shoot N were similar to those for shoot dry matter, except for buffel on the granitic soil where N yield was increased by 39% with no increase in shoot growth. Positive shade responses occurred in all 3 years but were reduced by extreme drought in year 3, particularly on the clay soil. Irrigation gave a greater shade response on the clay but not on the granitic soil. Root mass was lower under shade than in full sun. but there was no long-term trend of progressive decrease. and the change in N yield of roots did not appear to explain the gain in shoot N of the shaded pastures. Nitrogen percentage in the youngest expanded leaf was higher in the shade than the sun leaves only after about 2 to 2 5 months of shading. Surface soil nitrate and ammonia concentrations tended to be higher under shade for most harvests. Shade lowered temperature extremes of surface soil and litter by up to 10-12�C, and improved soil water status. compared with the sun plots. Soil water data were analysed to separate effects on plant water stress and soil microbial activity. The consistent positive response of shoot N yield to shade across grass species. weeds, and soil type. the delay in it becoming evident, and its longevity all support the hypothesis that shade enhances organic matter breakdown and N cycling. Harsh surface temperatures and low soil moisture in open sun pastures appear inimical to high microbial activity. Implications for pasture management are discussed. with the caveat that the outlined benefits of artificial shade may not necessarily arise with tree canopies.

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Seed germination, hydrothermal time models and the effects of global warming on a threatened high Andean tree species

Seed Science Research ◽

10.1017/s0960258512000189 ◽

2012 ◽

Vol 22 (4) ◽

pp. 287-298 ◽

Cited By ~ 7

Author(s):

Edgar E. Gareca ◽

Filip Vandelook ◽

Milton Fernández ◽

Martin Hermy ◽

Olivier Honnay

Keyword(s):

Global Warming ◽

Seed Germination ◽

Water Availability ◽

Tree Species ◽

Hydrothermal Time ◽

Germination Process ◽

Germination Characteristics ◽

Wide Range ◽

Maximum Temperatures ◽

Insight Into

AbstractSeed germination is a crucial event in a plant's life cycle. Because temperature and water availability are important regulators of seed germination, this process will likely be influenced by global warming. Insight into the germination process under global warming is thus crucial, and requires the study of a wide range of water availability and temperature conditions. As hydrothermal time (HTT) models evaluate seed germination for any combination of water potential and temperature, they can be suitable to predict global warming effects on seed germination. We studied the germination characteristics of the high Andean endemic tree speciesPolylepis besseri(Rosaceae), using HTT models. We were especially interested in the potential effects of global warming on seed germination. Assembly of HTT models forP. besseriwas fairly straightforward due to the lack of a seed dormancy mechanism. The models allowed prediction ofPolylepisgermination under constant and alternating temperatures. Initially, a global warming induced increase in the field minimum and mean temperature will increaseP. besserigermination, but as maximum temperatures rise above the optimum temperature for the species, seed germination will become jeopardized. Effects of global warming on seed germination are currently considerably underexplored. HTT models prove to be useful tools to study a plant species' general germination characteristics, and how they may become affected under global warming. For the endemic mountain tree speciesP. besseri, we predict an increase, followed by a decrease of seed germination under global warming.

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Effect of Forage Kochia on Seedling Growth of Cheatgrass (Bromus tectorum) and Perennial Grasses

Invasive Plant Science and Management ◽

10.1017/inp.2018.27 ◽

2018 ◽

Vol 11 (4) ◽

pp. 201-207

Author(s):

Parmeshwor Aryal ◽

M. Anowarul Islam

Keyword(s):

Seedling Growth ◽

Aboveground Biomass ◽

Bromus Tectorum ◽

Perennial Grass ◽

Perennial Grasses ◽

Grass Species ◽

Native Grasses ◽

Native Plant ◽

Competitive Effect ◽

Forage Kochia

AbstractForage kochia [Bassia prostrata(L.) A. J. Scott] is competitive with annual weeds and has potential for use in reclamation of disturbed land. However, land managers are reluctant to use forage kochia in revegetation programs due to lack of understanding of its compatibility with or invasiveness in the native plant community. We conducted two greenhouse experiments, one to compare the competitive effect of forage kochia versus perennial grasses on growth of cheatgrass (Bromus tectorumL.) and one to study the effect of forage kochia on growth of native perennial grasses. In the first experiment, a single seedling ofB. tectorumwas grown with increasing neighbor densities (0 to 5 seedlings pot−1) of either forage kochia, crested wheatgrass [Agropyron cristatum(L.) Gaertner ×A. desertorum(Fisch. ex Link) Schultes; nonnative perennial grass], or thickspike wheatgrass [Elymus lanceolatus(Scribn. & J. G. Sm.) Gould; native perennial grass].Bromus tectorumgrowth was reduced moderately by all three perennial neighbors, butA. cristatumandE. lanceolatushad more effect onB. tectorumwhen compared with forage kochia. This experiment was repeated and similar results were observed. In the second experiment, forage kochia was grown with each of four native cool-season grass species: basin wildrye [Leymus cinereus(Scribn. & Merr.) Á. Löve], bluebunch wheatgrass [Pseudoroegneria spicata(Pursh) Á. Löve],E. lanceolatus, and western wheatgrass [Pascopyrum smithii(Rydb.) Á. Löve]. Forage kochia had no effect on height, tiller number, and aboveground biomass of native grasses. Similarly, native grasses did not show a significant effect on forage kochia seedlings. This experiment was also repeated, and forage kochia somewhat reduced the aboveground biomass ofL. cinereusandP. spicata. However, all native grasses significantly reduced change in height, branching, and aboveground biomass of forage kochia. These results suggest that forage kochia interfered withB. tectorumseedling growth, but it showed little competitive effect on native grass seedlings.

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Water potentials of Salsola kali L. at differing levels of substrate water availability

Plant and Soil ◽

10.1007/bf00010014 ◽

1975 ◽

Vol 42 (2) ◽

pp. 387-393 ◽

Cited By ~ 1

Author(s):

Walter T. McDonough

Keyword(s):

Water Availability ◽

Salsola Kali ◽

Water Potentials

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Efficacy of Exotic Control Strategies for Restoring Coastal Prairie Grasses

Invasive Plant Science and Management ◽

10.1614/ipsm-d-14-00031.1 ◽

2014 ◽

Vol 7 (4) ◽

pp. 590-598 ◽

Cited By ~ 10

Author(s):

Karen D. Holl ◽

Elizabeth A. Howard ◽

Timothy M. Brown ◽

Robert G. Chan ◽

Tara S. de Silva ◽

...

Keyword(s):

Soil Removal ◽

Agricultural Land ◽

Control Strategies ◽

Control Treatment ◽

Grass Species ◽

Grass Cover ◽

Native Grass ◽

Exotic Grasses ◽

Coastal Prairie ◽

Topsoil Removal

AbstractRestoration in Mediterranean-climate grasslands is strongly impeded by lack of native propagules and competition with exotic grasses and forbs. We report on a study testing several methods for exotic plant control combined with planting native grasses to restore prairies in former agricultural land in coastal California. Specifically we compared tarping (shading out recently germinated seedlings with black plastic) once, tarping twice, topsoil removal, herbicide (glyphosate), and a control treatment in factorial combinations with or without wood mulch. Into each treatment we planted three native grass species (Elymus glaucus, Hordeum brachyantherum, andStipa pulchra) and monitored plant survival and cover for three growing seasons. Survival of native grass species was high in all treatments, but was slightly lower in unmulched soil removal and control treatments in the first 2 yr. Mulching, tarping, and herbicide were all effective in reducing exotic grass cover and enhancing native grass cover for the first 2 yr, but by the third growing season cover of the plant guilds and bare ground had mostly converged, primarily because of the declining effects of the initial treatments. Mulching and tarping were both considerably more expensive than herbicide treatment. Topsoil removal was less effective in increasing native grass cover likely because soil removal altered the surface hydrology in this system. Our results show that several treatments were effective in enhancing native grass establishment, but that longer term monitoring is needed to evaluate the efficacy of restoration efforts. The most appropriate approach to controlling exotics to restore specific grassland sites will depend not only on the effectiveness, but also on relative costs and site constraints.

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