Pasture management in semi-arid tropical woodlands: effects on herbage yields and botanical composition

1995 ◽  
Vol 35 (6) ◽  
pp. 705 ◽  
Author(s):  
JG McIvor ◽  
CJ Gardener
Keyword(s):  
Perennial Grasses ◽  
Percentage Increase ◽  
Botanical Composition ◽  
Pasture Management ◽  
Management Options ◽  
Stylosanthes Hamata ◽  
Large Yield ◽  
Native Pastures ◽  
Growing Conditions ◽  
Yield Responses

The effects of pasture management options (introduced legumes and grasses, superphosphate, timber treatment, cultivation before sowing, stocking rate) on the yield and botanical composition of pastures were measured from 1982 to 1992 at 2 sites, Hillgrove (extractable phosphorus, 50 mg P/kg) and Cardigan (extractable P, 6 mg/kg), near Charters Towers, northeastern Queensland. Despite generally poor establishment and growing conditions, some sown species (Stylosanthes hamata, S. scabra, Cenchrus ciliaris, Urochloa mosambicensis) established and persisted at both sites. The initial sown grass populations were small but yields increased markedly towards the end of the experiment. There were no yield responses by the native pastures to superphosphate, but the sown pastures responded at Cardigan, although not at Hillgrove. There were large yield responses to tree killing. The percentage increase in herbage yield following tree killing increased as the available water in the soil during the growing season decreased, and was greater at the higher fertility Hillgrove site. Overall, the native pastures were dominated by perennial grasses, but annual grasses and forbs increased on plots with live trees and high stocking rates towards the end of the trial. sown grasses, particularly C. ciliaris, became dominant (and are likely to remain so) at Hillgrove and on plots with superphosphate at Cardigan, especially where the trees were killed. Productive, mixed pastures with reasonable proportions of both grass and legume were maintained under live trees.

Satellite derived maps of pasture growth status: association of classification with botanical composition

1997 ◽  
Vol 37 (5) ◽  
pp. 547 ◽  
Author(s):  
P. J. Vickery ◽  
M. J. Hill ◽  
G. E. Donald
Keyword(s):  
Near Infrared ◽  
Perennial Grass ◽  
Vegetation Indices ◽  
Fast Growth ◽  
Perennial Grasses ◽  
Bayesian Probability ◽  
Cumulative Probability ◽  
Botanical Composition ◽  
South Wales ◽  
Native Pastures

Summary. Spectral data from the green, red and near-infrared bands of Landsat MSS and Landsat TM satellite imagery acquired in mid-spring were classified into 3 and 6 pasture growth classes respectively. The classifications were compared with a site database of botanical composition for the Northern Tablelands of New South Wales to examine the association between spectral growth class and pasture composition. Pastures ranged in composition from unimproved native perennial grasses through semi-improved mixtures of native and naturalised grasses and legumes to highly improved temperate perennial grasses and legumes. For 3 years of MSS data, the fast growth class had a mean botanical composition of about 80% improved perennial grass and 0% native; medium growth class averaged 46% improved perennial grass and 14% native; while the slow growth class had about 60% native and 1% improved perennial grass when averaged over 3 years of MSS data. For the 6 class TM data from a single year, a predictive logistic regression of cumulative probability was developed for percentage of ‘very fast’ growth pixels and ordered 10 percentile categories of improved perennial grass or native grass. Differences in patch characteristics between classes with MSS disappeared with TM reclassified to the same 3 class level. Most probable pasture type was inferred from 3 class MSS and TM data using Bayesian probability analysis. The resulting maps were similar in general appearance but detail was better with the TM data. The pasture growth classification identified highly improved perennial grass pastures and native pastures but sensitivity to intermediate pasture types was poor. Future improvement will come from direct measurement of biophysical characteristics using vegetation indices or inversion of reflectance models.

Pasture management in semi-arid tropical woodlands: dynamics of perennial grasses

2007 ◽  
Vol 29 (1) ◽  
pp. 87 ◽  
Author(s):  
John G. McIvor
Keyword(s):  
Perennial Grasses ◽  
Individual Species ◽  
Stocking Rate ◽  
Pasture Management ◽  
Management Options ◽  
Exotic Grasses ◽  
Heteropogon Contortus ◽  
Basal Cover ◽  
Growing Seasons ◽  
North East

The effects of a range of pasture management options (introduced legumes and grasses, superphosphate, timber treatment, cultivation before sowing and stocking rate) on the basal cover of perennial grasses were measured from 1982 to 1991 at two sites, ‘Hillgrove’ and ‘Cardigan’, near Charters Towers, in north-east Queensland. Colonisation and survival of eight native and exotic grasses were followed in permanent quadrats in a subset of treatments. Overall, there were significant changes in total basal cover of plots between years and with tree killing, but no significant differences in sown pastures, fertiliser or stocking rate. Basal cover increased when defoliation levels were less than 40% but increases were smaller at higher levels of defoliation and basal cover often declined when defoliation was greater than 60%. Basal cover declined when growing seasons were <10 weeks, remained static with 10–15 weeks growth, and increased when growing seasons were 16 weeks or longer. There was some colonisation in all years but large differences between years. The differences in colonisation between systems were generally small but there was a general trend for higher colonisation at higher stocking rates. Bothriochloa ewartiana (Domin) C.E.Hubb. and Chrysopogon fallax S.T.Blake had low, Heteropogon contortus (L.) P.Beauv. ex Roem.&Schult., Cenchrus ciliaris L. and Aristida spp. had intermediate, and Bothriochloa pertusa (L.) A.Camus and Urochloa mosambicensis (Hack.) Dandy had high colonising ability. Survival of individual species was generally similar at both sites except for Urochloa mosambicensis. Heteropogon contortus and U. mosambicensis at ‘Hillgrove’ were short-lived (<10% survival after 4 years), B. ewartiana, Themeda triandra Forssk. and Aristida spp. had intermediate survival (10–50%), and C. ciliaris, C. fallax, B. pertusa and U. mosambicensis at ‘Cardigan’ were long-lived (>50% survival). Annual survival rates increased with plant age, were higher in good growing seasons than in poor seasons, were higher for large plants than small plants, and were lower at high defoliation levels than where defoliation was less severe. The differences between species in ability to colonise and survive, and the small influence of management compared to seasonal effects on survival, are discussed to explain species performance in pastures.

scholarly journals Changes in yellow bristle grass (Setaria pumila) abundance after drought implications for pasture management

2009 ◽  
Vol 62 ◽  
pp. 211-216 ◽  
Author(s):  
K.N. Tozer ◽  
T.K. James ◽  
C.A. Cameron
Keyword(s):  
Key Management ◽  
Perennial Grass ◽  
Perennial Grasses ◽  
Botanical Composition ◽  
Annual Grass ◽  
Bare Ground ◽  
Pasture Management ◽  
Soil Calcium ◽  
Annual Grasses ◽  
Previous Summer

Yellow bristle grass (YBG) which is a summeractive annual grass reduces pasture quality and becomes unpalatable to stock as panicles mature Farmers are concerned that an extreme drought from November 2007 to March 2008 may have facilitated the spread of YBG and other summeractive annual grass weeds Botanical composition was assessed on 12 Waikato dairy farms in February 2009 and YBG abundance was related to key management factors These findings were compared with data collected from the same farms (February 2008) during the drought Between years ryegrass cover and the proportion of bare ground decreased These components were replaced by two summeractive annual grasses YBG and summer grass and to a lesser extent summeractive perennial grasses clovers and dicots In 2009 YBG cover was negatively associated with summeractive perennial grass cover and pH and positively associated with YBG cover in the previous summer and soil calcium levels

Population dynamics and stability of Stylosanthes hamata cv. Verano in grazed pastures

1982 ◽  
Vol 33 (1) ◽  
pp. 63 ◽  
Author(s):  
CJ Gardener
Keyword(s):  
Perennial Grass ◽  
Perennial Grasses ◽  
Botanical Composition ◽  
Grazed Pastures ◽  
Stylosanthes Hamata ◽  
Wide Range ◽  
Annual Grasses ◽  
Seed Reserves ◽  
Stable Association

The longevity, regeneration and seed reserves of Stylosantes hamata cv. Verano were studied in grazed pastures at Lansdown, north Queensland, over a 9-year period. Stability was assessed in terms of frequency of appearance and fluctuations in botanical composition. Plants proved short-lived, with a half-life of only 3 months. The majority therefore died in their seedling year, and only 0.03 % survived to the end of the third year. In most years, S. hamata had to re-establish almost entirely from seed. Despite this, S. hamata was a highly persistent legume in the long term owing to its consistently high seed reserves and ready regeneration from seed. In one paddock, for example, it re-established in all quadrats after disappearing from 76% of them the previous year. This long-term persistence was not, however, reflected in yield stability; the content of S. hamata in one paddock changed from 6 to 68% in consecutive years. Low legume yields were recorded when seedlings of S, hamata competed poorly with the annual grasses. Higher yields occurred when more than 20 % of the population comprised perennial S. hamata plants. Retention of the perennial grasses reduced the amplitude of the fluctuations in yields of S. hamata. The perennial grass and S. hamata formed an intimate and stable association. There were only small effects of stocking rate and superphosphate on the persistence of S. hamata, which suggests that the legume is highly tolerant of a wide range of management levels, although more precise management is needed for high animal production.

Pasture management in semi-arid tropical woodlands: regeneration of degraded pastures protected from grazing

2001 ◽  
Vol 41 (4) ◽  
pp. 487 ◽  
Author(s):  
J. G. McIvor
Keyword(s):  
Initial Conditions ◽  
Basal Area ◽  
Ground Cover ◽  
Botanical Composition ◽  
Site Condition ◽  
Pasture Management ◽  
Soil Seed Banks ◽  
North East ◽  
Wide Range ◽  
Native Pastures

Regeneration of native and oversown pastures following exclusion of grazing was studied over 3 years on a fertile soil at Hillgrove, near Charters Towers, north-east Queensland. The pastures covered a wide range of initial conditions reflecting the grazing pressures they had been exposed to during 2 dry years before enclosure. Pasture measurements made before the exclusion of grazing (yield, botanical composition, basal area, ground cover, height, soil seed banks) were related by regression analysis to subsequent changes in site condition described by a site condition value, calculated from herbage yields and botanical composition, to determine suitable predictors of regeneration during resting from grazing. The pastures recovered (increases in soil cover, grass basal area and the proportion of desirable species) under the generally favourable growing conditions during the period of enclosure although some plots, initially in poor condition, had not recovered after 3 years. There were only minor differences between the native and oversown pasture types in their recovery. Relative yields and site condition values were not affected by pasture type and botanical composition index values differed with pasture type in 1989 only. The site condition values of both pasture types after the first year of enclosure were closely and positively related to all the pasture characteristics measured the previous year except for soil seed numbers in the native pastures. All characteristics could be used to predict site condition value and potential of the pasture to regenerate, and their merits are discussed. The proportion of desirable species in the pasture combined with level of ground cover is suggested as a useful means of predicting regeneration and potential for future grazing.

BOTANICAL COMPOSITION AND PRODUCTIVITY OF PERENNIAL GRASSES AGROPHYTOCENOSES WITH TETRAPLOID MEADOW CLOVER

1970 ◽  
pp. 59-62
Author(s):  
N. I. Kasatkina ◽  
Zh. S. Nelyubina
Keyword(s):  
Dry Weight ◽  
Single Species ◽  
Lotus Corniculatus ◽  
Specific Weight ◽  
Biological Properties ◽  
Phleum Pratense ◽  
Perennial Grasses ◽  
High Yield ◽  
Botanical Composition ◽  
The Third

The biological properties of plants, their mutual relations under different growth conditions and at different periods of their life, must be known for obtaining highly productive agrophytocenoses with participation of a meadow clover (Trifolium pratense L.). Botanical composition and fodder productivity of perennial grasses in agrocenoses with participation of meadow tetraploid clover Kudesnik were studied in 2014-2017. It was revealed that in the first and second years of use the agrophytocenosis, the yield of green mass was formed due to meadow tetraploid clover, the share of its participation in the first mowing was at level of 71-87% and 64-97% respectively. Specific weight of clover in multispecies agrocenoses considerably decreased by the third year of use: in the first mowing up to 32-68%, in the second - up to 8-52%. At the same time, the percentage of long-term herbaceous grasses increased: meadow timothy (Phleum pratense L.) - up to 34-54%, eastern galega (Galéga orientális Lam.) - up to 33%, changeable alfalfa (Medicago x varia Martyn) - up to 22-54%, lotus corniculatus (Lotus corniculatus L.) - up to 14-19%. The proportion of weed admixture in single-species clover planting was 12%, in agrocenoses - 2-14%. The grass mixtures clover + timothy and clover + alfalfa + timothy were less infested by weeds. High yield of dry weight of single-species sowing of meadow tetraploid clover was obtained in the first two years of use - 7.8 and 6.5 tons / ha, respectively. By the third year of use, the productivity of clover has decreased to 2.9 t / ha. On average, for three years of use, the highest yield (6.2-6.3 t / ha) was formed by agrocenoses meadow tetraploid clover + meadow timothy and meadow tetraploid clover + changeable alfalfa + meadow timothy.

Beef production from native pastures sown to fine-stem stylo in the Burnett region of south-eastern Queensland

1979 ◽  
Vol 19 (97) ◽  
pp. 140 ◽  
Author(s):  
EJ Bowen ◽  
KG Rickert
Keyword(s):  
Stocking Rate ◽  
Management Options ◽  
North West ◽  
Heteropogon Contortus ◽  
South Eastern ◽  
Continuous Grazing ◽  
Weight Gains ◽  
The Mean ◽  
Native Pastures ◽  
Stocking Rates

At Gayndah, south-eastern Queensland, a native Heteropogon contortus pasture, sown to fine-stem stylo (Stylosanthes guianensis var. intermedia), and invaded by red natal grass (Rhynchelytrum repens), was grazed by weaner steers from June 1 in three treatments : heavy and light put-and-take grazing for five years from 1971, and set-stocked at 1.37 animals ha-1 for two years from 1974. Weight gains in the put-and-take treatments were not significantly different. The mean annual liveweight gain was 167 kg animal-1 at a mean equivalent stocking rate of 1.47 animals ha-1. Over the same period unsown native pasture, cleared of timber, gave a gain of 62 kg animal-1 at 0.62 animals ha-1. In all seasons except summer, weight gains declined linearly with stocking rate and in 1972-73, with a mean equivalent stocking rate of 2.66 animals ha-1, the annual gain was almost halved. When equivalent stocking rates were 0.9, 0.9, 1.8 and 1.2 animals ha-1 in winter, spring, summer and autumn, the respective gains were 4, 73, 65 and 45 kg animal-1. The set-stocked treatment had a mean annual gain of 147 kg animal-1. At another site 116 km north-west of Gayndah, two paddocks of Heteropogon contortus and fine-stem stylo were set-stocked with weaners over four years. One paddock had four applications of superphosphate of 250 kg ha-1. The mean annual liveweight gains were significantly different, being 154 and 143 kg animal-1 in the fertilized and unfertilized paddocks at mean stocking rates of 0.83 and 0.74 animals ha-1, respectively. In a grazing protection experiment the density of fine-stem stylo declined exponentially with an accumulation of pasture dry matter in spring and summer. Heavy continuous grazing, an annual hay cut and an accidental fire all increased the density of fine-stem stylo. Management options to maintain the density of fine-stem stylo and the relative importance of the legume and grass to animal production are discussed.

Sustainable grazing systems for the Central Tablelands of New South Wales. 1. Agronomic implications of vegetation - environment associations within a naturalised temperate perennial grassland

2006 ◽  
Vol 46 (4) ◽  
pp. 439 ◽  
Author(s):  
W. McG. King ◽  
P. M. Dowling ◽  
D. L. Michalk ◽  
D. R. Kemp ◽  
G. D. Millar ◽  
...  
Keyword(s):  
Perennial Grass ◽  
Acid Soils ◽  
Late Summer ◽  
Trifolium Subterraneum ◽  
Moisture Stress ◽  
Recent Change ◽  
Perennial Grasses ◽  
Management Options ◽  
Eastern Australia ◽  
Winter Annual

Temperate perennial grass-based pastures dominate the high rainfall zone of south-eastern Australia and support a major livestock production industry. This area has experienced a recent change in overall pasture condition, however, typified by a reduction in the abundance of perennial grasses and an increasingly prominent winter-annual grass weed component. Improving the condition and productivity of these pastures can be achieved by improved management but this requires better knowledge of the interactions between management options and pasture species composition and of the interaction between pasture vegetation and the complex effects of a heterogeneous landscape. This paper reports the results of an intensive survey of a 60-ha paddock that was designed to identify the species present, determine their patterns of distribution and examine the relationships between pasture vegetation and the environment. The survey of species present in late summer was supplemented by the identification of seedlings that later emerged from extracted soil cores and by soil physical and chemical analyses. Data were analysed using ordination and interpreted with GIS software so that topographic features could be considered. The most frequently identified taxa were Hypochaeris radicata, Austrodanthonia spp. and Bothriochloa spp. (in late summer) and Vulpia spp., Bromus molliformis and Trifolium subterraneum (winter-annual species). Austrodanthonia spp. were commonly found on the drier ridges and more acid soils with lower phosphate levels. These were also the areas dominated in spring by Vulpia spp. and were generally lower in plant species richness overall. The most species-rich areas occurred downslope where soil fertility was higher and less moisture stress was presumably experienced. The measured environmental factors explained a substantial proportion of the variation in the vegetation dataset, which underlined the importance of considering landscape effects in the management of typical tablelands pastures.

scholarly journals Comparing the phosphorus requirements of wheat, lupin, and canola

2008 ◽  
Vol 59 (11) ◽  
pp. 983 ◽  
Author(s):  
M. D. A. Bolland ◽  
R. F. Brennan
Keyword(s):  
Growth Rates ◽  
Triticum Aestivum L ◽  
Yield Response ◽  
Brassica Napus L ◽  
Crop Species ◽  
P Concentration ◽  
Large Yield ◽  
P Content ◽  
Yield Responses ◽  
Phosphorus Requirements

Spring wheat (Triticum aestivum L.), lupin (Lupinus angustifolius L.), and canola (Brassica napus L.) are the major crop species grown in rotation on the predominantly sandy soils of south-western Australia. Comparisons among the species for yield responses to applied phosphorus (P), effects of applied P on growth rates of shoots, P response efficiency for shoot and grain production, and the pattern for accumulation of P into shoots during growth and into grain at maturity are rare, or are not known, and were quantified in the glasshouse study reported here. Size and P content (P concentration multiplied by yield) of sown seed were in the order canola < wheat < lupin. Therefore, yield responses to applied P were first observed at ~10 days after sowing (DAS) for canola, ~17 DAS for wheat, and ~60 DAS for lupin. Lupin shoots showed no yield response to applied P at the first harvest at 51 DAS. Otherwise all species showed large yield, P concentration, and P content responses to applied P for all harvests at 51, 78, 87, 101, 121, and 172 DAS. To produce 90% of the maximum grain yield, the relevant data for cropping, lupin required ~67% less P than wheat, canola required ~40% less P than wheat, and canola required ~75% more P than lupin. Growth rates, and P response efficiency, were generally largest for canola, followed by wheat, then lupin. For shoots, P accumulation was in the order lupin > wheat > canola at 51 DAS, canola > wheat > lupin at 78 and 87 DAS, canola > wheat = lupin at 101 DAS, and all 3 species were about similar at 121 DAS. For accumulation of P into shoots plus grain at maturity (172 DAS) the order was canola > lupin > wheat, and for grain only was canola > wheat = lupin.

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