Grass Growth in Response to Time of Rainfall and Season Along a Climate Gradient in Australian Rangelands.

1997 ◽  
Vol 19 (1) ◽  
pp. 95 ◽  
Author(s):  
BH Walker ◽  
FR Mcfarlane ◽  
JL Langridge
Keyword(s):  
Soil Moisture ◽  
Perennial Grass ◽  
Management Strategies ◽  
The Other ◽  
Green Leaf ◽  
Grass Species ◽  
Seasonal Growth ◽  
Available Soil Moisture ◽  
Time Of Year ◽  
Grass Growth

Percentage green leaf and height of the major perennial grass species was estimated fortnightly at six locations along a rainfall predictability gradient from Katherine (most predictable) to Lake Mere near Cobar (aseasonal), and regressed on estimated plant available soil moisture (PASM) and time of year (T). Green leaf is more strongly related to T at Katherine and to PASM at Lake Mere with the other sites in-between. Differences between species in terms of seasonal growth phenology were minor, at all sites, and there were no meaningful patterns in percentage contributions by the species to sward biomass. A strong inter-seasonal rainfall pattern over the period of the study may have masked phenological differences between species, but it is also possible that changes in species composition very soon after livestock were introduced resulted in a decline in phenological differentiation. Whatever the reason, the differences observed in this study would ~ot warrant their use in the formulation of management strategies.

Studies on the Reproductive Biology of Leafy Spurge (Euphoriba esula)

Weed Science ◽  
1979 ◽  
Vol 27 (1) ◽  
pp. 106-109 ◽  
Author(s):  
L. A. Morrow
Keyword(s):  
Soil Moisture ◽  
Dry Matter ◽  
Perennial Grass ◽  
Leafy Spurge ◽  
Euphorbia Esula ◽  
First Year ◽  
Growth Room ◽  
Available Soil Moisture ◽  
Second Year ◽  
Field Plots

Studies on the development of leafy spurge (Euphorbia esula L.) were conducted in the field and growth room. Sixteen months after planting in field plots, leafy spurge plants arising from underground bud-producing root segments, transplanted seedlings, or seeds averaged 96, 83, and 136 shoots per plant, respectively, when grown free of interference from other vegetation. A number of plants arising from each source flowered the first year, and all plants flowered and produced seed the second year after planting. When grown in a perennial grass sod consisting of crested wheatgrass [Agropyron desertorum (Fisch. ex Link) Schult.] and smooth brome (Bromus inermis Leyss.), no plant flowered or produced additional shoots. Soil moisture was less where a dense sod was present. In the growth room, total dry matter of tops and roots was greatest at a soil temperature of 18.3 C or higher, and plant height was greatest at 33.3 C. An early emerging crop might suppress leafy spurge by utilizing the available soil moisture early in the growing season.

Metabolism and distribution of grasses in tropical flooded savannas in Venezuela

1990 ◽  
Vol 6 (1) ◽  
pp. 77-89 ◽  
Author(s):  
Ernesto Medina ◽  
Norma Motta
Keyword(s):  
Reductase Activity ◽  
Perennial Grass ◽  
The Other ◽  
C3 Plants ◽  
Grass Species ◽  
Carboxylase Activity ◽  
Pronounced Increase ◽  
Leersia Hexandra ◽  
Relative Water ◽  
C3 Grasses

ABSTRACTFlooded savannas in south-west Venezuela consist of seasonal, marshy and flooded grassland communities, the distribution of which depends on soil level. Seasonal grasslands are dominated by tuft-forming, rhizomatous C4-grasses (exemplified by Paspalum chaffanjonii in this study), while flooded grasslands are dominated by stoloniferous grasses which develop rooted, floating culms during the rainy season (Leersia hexandra and Hymenachne amplexi-caulis). The interface between these two communities is a marshy grassland dominated by stoloniferous grass species which tolerate flooding to a depth of 10 to 25 cm (Panicum laxum and Leersia hexandra). All perennial grass species in flooded grasslands behave as typical C3 plants, while marshy grasslands are dominated by Panicum laxum, a species with reduced photo-respiration, low RuBP/PEP-carboxylase ratios, and low absolute RuBP-carboxylase activity compared to C3 grasses. It also has lower photosynthetic rates than the other grass species. Hymenachne amplexicaulis appears to be the least drought tolerant from the species selected, in accordance with its distribution in the wettest side of the flooding gradient studied. The other species showed marked reduction in relative water content and pronounced increase in leaf proline content in drought experiments lasting 6 to 30 days. Alcohol dehydrogenase increased markedly in response to anaerobiosis in the root environment in the tuft forming grasses, while the stoloniferous species with ascending culms were least affected by this treatment, probably as a result of better aeration inside the culms and also to the production of adventitious roots in upper nodes. Nitrate reductase activity increased as a result of anaerobiosis in the roots but not in the leaves, of all species except Leersia hexandra. No difference among the species was found in malate accumulation, or the activity of malic enzyme.

scholarly journals Exploring the potential of wild perennial grasses as a biomass source in semi-arid Mediterranean environments

2018 ◽  
pp. 103-111 ◽  
Author(s):  
Javier Gulias ◽  
Rita Melis ◽  
Danilo Scordia ◽  
Josep Cifre ◽  
Giorgio Testa ◽  
...  
Keyword(s):  
Perennial Grass ◽  
Management Strategies ◽  
Net Photosynthesis ◽  
Perennial Grasses ◽  
Grass Species ◽  
Marginal Lands ◽  
Mediterranean Environments ◽  
Wild Accessions ◽  
Long Term Performance ◽  
Term Performance

In Mediterranean environments, few perennial grass species are available for cultivation in rainfed systems and marginal lands, where plants with excellent adaptation are required. The aim of the present work was to determine the potentiality of five native Mediterranean perennial grasses for lignocellulosic biomass production. Wild accessions of three hemicryptophytes (Ampelodesmos mauritanicus, Hyparrhenia hirta, and Piptatherum miliaceum) and two geophytes (Saccharum spontaneum ssp. aegyptiacum and Sorghum halepense) were collected at three Mediterranean sites (Sicily, Sardinia and Majorca), and their morphological, physiological, productivity and quality traits were evaluated in the field. The species differed in height, with S. spontaneum and A. mauritanicus being the tallest. The leaf mass ratio ranged from 0.23 to 1.0 g g–1 among species. Maximum net photosynthesis was measured in the C4 species S. spontaneum and S. halepense (26.6 and 23.8 mmol CO2 m–2 s–1, respectively). A. mauritanicus showed the lowest transpiration rate and the highest instantaneous water use efficiency (2.7 mmol H2O m–2 s–1 and 6.9 mmol CO2 mmol H2O–1, respectively). S. spontaneum was the most productive species, yielding more than 18 Mg DM ha–1 as a three-year average. The highest content of acid detergent lignin was found in P. miliaceum, while A. mauritanicus was the species richest in hemicellulose and cellulose and poorest in ash. S. spontaneum showed the highest moisture content at harvest. Overall, the studied species showed interesting morphological, physiological, productive and qualitative traits. Nevertheless, additional research is necessary to investigate their long-term performance under different management strategies.

Moisture use characteristics of sugarcane genotypes under different available soil moisture regimes in alluvial entisols

1988 ◽  
Vol 110 (1) ◽  
pp. 5-11 ◽  
Author(s):  
R. L. Yadav ◽  
S. R. Prasad
Keyword(s):  
Soil Moisture ◽  
Sandy Loam ◽  
Field Trials ◽  
The Other ◽  
Cane Yield ◽  
Area Index ◽  
Moisture Regimes ◽  
Available Soil Moisture ◽  
Moisture Percentage ◽  
Loam Soil

SummaryTo study the response of three sugarcane genotypes (CO 1148, COJ 64 and CO 1158) to variations in moisture availability in sandy loam soil (entisol), field trials were conductedat Lucknow (26·5° N, 80·5° E, 120 m altitude) during 1984–5 and 1985–6. Three moisture regimes, i.e. wet (irrigation at 75% available soil moisture (ASM)), moist (irrigation at 50% ASM) and dry (irrigation at 25% ASM) were maintained during the pre-monsoon (before June) period in spring-planted (February-March) sugarcane. During the summer months (until June)the variety CO 1148 had a significantly greater sheath moisture percentage than COJ 64 and CO 1158. Under stress conditions, leaf area index was reduced most in COJ 64 and least in CO 1148.Underground shoots and roots grew faster in CO 1148, and the growth of above-ground parts was quicker in COJ 64. Compared with the 75% ASM regime the reduction in cane yield in the 25% regime was more in COJ 64 and CO 1158 (31 t/ha) than in CO 1148 (12 t/ha). The water requirement of COJ 64 was greater than that of the other varieties. Therefore, for higheryields COJ 64 needed frequent irrigation whereas CO 1148 performed well even under moderate irrigation (50% ASM).

scholarly journals Native Perennial Grasses in Highway Medians: Pre- and Postplant Techniques for Establishment in a Mediterranean Climate

2008 ◽  
Vol 1 (4) ◽  
pp. 368-375
Author(s):  
Stephen L. Young ◽  
Victor P. Claassen
Keyword(s):  
Plant Density ◽  
Perennial Grass ◽  
Field Studies ◽  
Perennial Grasses ◽  
Species Selection ◽  
Grass Species ◽  
Native Plant ◽  
Grass Establishment ◽  
Grass Growth ◽  
Native Perennial Grass

AbstractWithin highway rights-of-way, native perennial grasses provide desirable services to support natural and human constructed ecosystems. However, native perennial grass establishment in annual grass dominated roadsides of semiarid and Mediterranean climates of the western United States requires specific cultural and chemical management treatments to control weeds. In 2004, field studies were conducted in Sacramento Valley, California to determine the effect of herbicide, disc cultivation, and species selection on native perennial grass establishment and annual weed persistence. Perennial grass species mixes common to drier and wetter upland areas in northern California were drill seeded at two sites (I-5 North and I-5 South) that had been burned in 2003 and received weed control (i.e., herbicide, cultivation, mowing) in spring 2004. Herbicides were the most important treatments for native perennial grass establishment and weed reduction. Native perennial grass species persistence was largely unaffected by cultivation or native plant accessions at these sites. Native perennial grass density increased at I-5 North in the second year of growth (2006) resulting in a plant density totaled across all herbicide regimes of 3.9 plants m−1 compared to 2.5 plants m−1 at I-5 South. Vigorous native perennial grass growth in the more fertile and less droughty soils of I-5 North helped to limit annual weeds through competition, which is anticipated to reduce the need for chemical and mechanical control in years following early establishment.

Herbicide Control Strategies for Ventenata dubia in the Intermountain Pacific Northwest

2016 ◽  
Vol 9 (2) ◽  
pp. 128-137 ◽  
Author(s):  
John M. Wallace ◽  
Timothy S. Prather
Keyword(s):  
Pacific Northwest ◽  
Control Strategies ◽  
Integrated Management ◽  
Perennial Grass ◽  
Grass Species ◽  
Intermediate Wheatgrass ◽  
Herbicide Treatments ◽  
Exotic Annual Grass ◽  
Grass Growth ◽  
Herbicide Control

Ventenata dubia is an exotic annual grass that has become increasingly invasive in various perennial grass systems throughout the Intermountain Pacific Northwest. Currently, little information is available to landowners about herbicide control options. In our first field study, we evaluated V. dubia control efficacy and perennial grass tolerance of herbicides applied pre-emergence (PRE) at two locations and as an early postemergence (EPOST) application at four different conservation reserve grasslands, with each grassland dominated by different perennial grass species. Treatments included flufenacet plus metribuzin (303 + 76 g ai ha−1 [0.27 + 0.07 lb ai ac−1]), propoxycarbazone-sodium (49 g ai ha−1 [0.04 lb ai ac−1]), rimsulfuron (53 g ai ha−1 [0.05 lb ai ac−1]), sulfosulfuron (53 g ai ha−1 [0.05 lb ai ac−1]), and imazapic (105 g ai ha−1 [0.09 lb ai ac−1]). Rimsulfuron and flufenacet plus metribuzin applied PRE provided > 90% control 10 mo after treatment (MAT). Rimsulfuron and sulfosulfuron applied EPOST provided > 90% control 9 MAT. Herbicide injury to bluebunch and intermediate wheatgrass was negligible across treatments. Imazapic and sulfosulfuron applied EPOST resulted in significant injury to smooth brome and timothy. In our second study, we addressed the following question: Will fall herbicide plus fertilizer treatments improve V. dubia control compared with herbicide treatments alone? We imposed fall herbicide treatments in main plots and fertilizer treatments (fall N, fall P, fall K, fall PK, spring N, NPK) in split plots at three study locations. Herbicide treatments resulted in high levels of V. dubia control. Differences in V. dubia abundance among fertilizer treatments were negligible 9 MAT. Within herbicide control plots, spring N and NPK treatments resulted in significant increases in perennial grass cover and decreases in V. dubia cover (9 MAT). This result indicates that spring N applications timed to the onset of perennial grass growth could be utilized as a component of an integrated management strategy for V. dubia in invaded perennial grass systems.

Macropods, feral goats, sheep and cattle. 2. Equivalency in what and where they eat

2019 ◽  
Vol 41 (6) ◽  
pp. 519 ◽  
Author(s):  
Lester Pahl
Keyword(s):  
Diet Composition ◽  
Perennial Grass ◽  
Climatic Conditions ◽  
Perennial Grasses ◽  
The Other ◽  
Green Leaf ◽  
Wide Range ◽  
Annual Grasses

The extent to which sheep, cattle, feral goats, red kangaroos, western grey kangaroos, euros and eastern grey kangaroos are equivalent in their use of the Australian southern rangelands is partly dependent on the extent to which their diets and foraging areas overlap. These herbivores all eat large amounts of green annual grasses, ephemeral forbs and the green leaf of perennial grasses when they are available. Overlap in use of these forages by all seven herbivores is concurrent and high. As the abundance of these preferred forages declines, sheep, cattle and feral goats consume increasing amounts of mature perennial grasses and chenopod and non-chenopod perennial forbs. Red kangaroos and western grey kangaroos continue to graze mature perennial grasses longer than sheep, cattle and feral goats, and only switch to perennial forbs when the quantity and quality of perennial grasses are poor. Consequently, overlap in use of perennial forbs by sheep, cattle, feral goats, red kangaroos and western grey kangaroos is sequential and moderately high. When palatable perennial forbs are eaten out, the diets of all herbivores except feral goats comprise predominantly dry perennial grass, and overlap is again concurrent and high. In comparison, feral goats have higher preferences for the browse of a wide range of shrubs and trees, and switch to these much earlier than the other herbivores. When perennial grasses and perennial forbs become scarce, sheep, feral goats and cattle browse large shrubs and trees, and overlap is sequential and high. If climatic conditions remain dry, then red and western grey kangaroos will also browse large shrubs and trees, but overlap between them, sheep, cattle and goats is sequential and low. In contrast to the other herbivores, the diets of euros and eastern grey kangaroos are comprised predominantly of perennial grasses, regardless of climatic conditions. As for diet composition, concurrent overlap in foraging distributions of sheep, cattle, feral goats and the four species of macropods is often low. However, over periods of several months to two or three years, as climatic conditions change, overlap in foraging distributions is sequential and high. While equivalency in what and where these herbivores eat is not quantifiable, it appears to be high overall. This is particularly so for perennial grass, which is the dominant forage for herbivores in the southern rangelands.

Gaseous nitrogen loss from temperate perennial grass and clover dairy pastures in south-eastern Australia

2003 ◽  
Vol 54 (6) ◽  
pp. 561 ◽  
Author(s):  
R. J. Eckard ◽  
D. Chen ◽  
R. E. White ◽  
D. F. Chapman
Keyword(s):  
Ammonium Nitrate ◽  
Nitrogen Loss ◽  
Perennial Grass ◽  
Management Strategies ◽  
The Other ◽  
N Losses ◽  
South Eastern ◽  
Eastern Australia ◽  
Different Seasons ◽  
South Eastern Australia

The use of nitrogen (N) fertiliser on dairy pastures in south-eastern Australia has increased exponentially over the past 15 years. Concerns have been raised about the economic and environmental impact of N loss through volatilisation and denitrification. Emissions of NH3, N2, and N2O were measured for 3 years in the 4 different seasons from a grazed grass/clover pasture, with or without 200 kg N fertiliser/ha, applied as ammonium nitrate and urea.Nitrogen-fertilised treatments lost significantly more N than the control treatments in all cases. More NH3 was lost from urea-fertilised treatments than from either the control or ammonium nitrate treatments, whereas ammonium nitrate treatments lost significantly more N through denitrification than the control or urea treatments in all seasons, except for summer. More NH3 was lost in summer than in the other seasons, whereas denitrification and N2O losses were highest in winter and lowest in summer. The total annual NH3 loss from the control, ammonium nitrate, and urea treatments averaged 17, 32, and 57 kg N/ha.year, respectively. Annual denitrification losses were estimated at around 6, 15, and 13 kg N/ha.year for the control, ammonium nitrate, and urea treatments, respectively. Total gaseous N losses were estimated to be 23, 47, and 70 kg N/ha.year from the control, ammonium nitrate, and urea treatments respectively.Although the use of ammonium nitrate fertiliser would significantly reduce NH3 volatilisation losses in summer, this fertiliser costs 45% more per unit N than urea, so there is no economic justification for recommending its use over urea for the other seasons. However, the use of urea during the cooler, wetter months may result in significantly less denitrification loss. The results are discussed in terms of potential management strategies to improve fertiliser efficiency and reduce adverse effects on the environment.

Functional Environment of Downy Brome Communities in Relation to Weed Control and Revegetation

Weed Science ◽  
1970 ◽  
Vol 18 (1) ◽  
pp. 154-162 ◽  
Author(s):  
Raymond A. Evans ◽  
H. Richard Holbo ◽  
Richard E. Eckert ◽  
James A. Young
Keyword(s):  
Soil Moisture ◽  
Weed Control ◽  
Perennial Grass ◽  
Critical Periods ◽  
Downy Brome ◽  
Weed Growth ◽  
Control Growth ◽  
Available Soil Moisture ◽  
Soil Temperatures ◽  
Moisture Conditions

We measured some of the more important biologic and microclimatic parameters of the functional environment of downy brome (Bromus tectorumL.) communities during the establishment period of seedlings of intermediate wheatgrass (Agropyron intermedium(Host) Beauv., var. Amur). These measurements were made in relation to weed control and seeding treatments. Weed growth and establishment of replacement vegetation were directly related to available soil moisture and favorable temperatures in the immediate environment of growing plants. Lack of available soil moisture during critical periods of the growing season was the major deterrent to seeding success. The limited precipitation stored as soil moisture was available to perennial grass seedlings where weeds were controlled. Without weed control, growth of downy brome preempted the effective precipitation, and moisture became limiting for growth of perennial grass seedlings. Seeding in furrows, along with weed control, further improved moisture conditions for the seedlings. Also, use of furrows enhanced seedling growth by lowering maximum air and soil temperatures in the seedlings' immediate environment.

Hymenachne acutigluma (Steud.) Gilliland in GBS 20:314 - An exceptionally important perennial grass for anatomy and indigenous practice.

2016 ◽  
Vol 5 (04) ◽  
pp. 4958
Author(s):  
Dulal De
Keyword(s):  
Perennial Grass ◽  
Secondary Growth ◽  
Grass Species ◽  
Stem Anatomy

Hymenachne acutigluma (Steud.) Gilliland, a robust rhizomatous perennial grass spreads on moist and swampy land and also floating in water. Being a grass species, they do not have any cambium for secondary growth. A peculiarity in stem anatomy especially the spongy pith of secondary tissues found in absence of the cambium. The origin and development of the parenchymatous pith tissues has been investigated in the present study. Economically this spongy pith is of very much potent for its high absorbing and filtering capacity and also used as a good fodder.

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