Nutritional evaluation of south-west Queensland pastures. 1. The botanical and nutrient content of diets selected by sheep grazing on Mitchell grass and mulga/grassland associations

1986 ◽  
Vol 37 (3) ◽  
pp. 289 ◽  
Author(s):  
NP McMeniman ◽  
IF Beale ◽  
GM Murphy
Keyword(s):  
Nutrient Concentration ◽  
Nutrient Content ◽  
Botanical Composition ◽  
Sheep Grazing ◽  
South West ◽  
Low Concentrations ◽  
Drought Conditions ◽  
Acacia Aneura ◽  
Grassland Site ◽  
Grassland Types

The botanical composition and nutrient content of diets selected by sheep grazing Mitchell grass (Astrebla spp.) and mulga (Acacia aneura)/grassland pastures in south-west Queensland were studied during a four-year period. Forbs, when present in the sward, contributed significantly to the diets on both grassland types. Under drought conditions grasses were the major components of the diets of sheep grazing Mitchell grassland pastures, while under similar conditions on the mulga/grassland pastures at least 35% of the diet was mulga (Acacia aneura); some mulga was present in the diet at all times. In general, the nutrient content of the green leaves of grasses and forbs growing on the mulga/ grassland association was similar, whereas on the Mitchell grass association green forbs had a higher nutrient concentration than did the leaves of green grasses. Both the grasses and forbs on the mulga/ grassland site had lower P and sodium concentrations than those on the Mitchell grassland site. When seasonal conditions were average to good the concentrations of all nutrients in the diets of sheep grazing the Mitchell grass association were judged to be adequate. However, when the pastures dried out the diets contained low concentrations of N (7.0 g/kg DM), P (0.9 g/kg DM), sodium (O.lg/kg DM) and copper (3.8 mg/kg DM). On the mulga/grassland site dietary concentrations of P and sodium were low at all times and under drought conditions the N:S ratio fell to 16.8:1. The concentrations of other nutrients in the diets were high enough to provide the sheep's theoretical requirements at all times.

scholarly journals Effects of the MaxP (TM) endophyte in tall fescue on pasture production and composition, and the sheep grazing preference in a dryland environment

2007 ◽  
Vol 13 ◽  
pp. 259-262
Author(s):  
K.N. Tozer ◽  
S. Ates ◽  
N.R. Mapp ◽  
M.C. Smith ◽  
R.J. Lucas ◽  
...  
Keyword(s):  
New Zealand ◽  
Tall Fescue ◽  
Dry Matter ◽  
Early Spring ◽  
Botanical Composition ◽  
Sheep Grazing ◽  
Pasture Production ◽  
Basal Diameter ◽  
Matter Production ◽  
Annual Grasses

Pasture growth, botanical composition and sheep grazing preference were measured over 20 months in tall fescue (cultivar Advance), without endophyte (Nil) or infected with AR542 (MaxPTM) endophyte, and clover pastures sown into a dryland soil, Canterbury, New Zealand. Pastures were rotationally grazed with sheep, with grazing preference for the two endophyte treatments measured in late autumn and early spring. Annual dry matter production from April 2004 to April 2005 was not significantly different between AR542 (6293 kg DM/ha) and Nil (5864 kg DM/ha) tall fescue. The number of tall fescue plants/m2 and their basal diameter was greater for AR542 (35 plants/m2, 7.5 cm diameter) than Nil endophyte tall fescue (28 plants/m2, 6.8 cm diameter). AR542 endophyte tall fescue pastures had fewer weeds, mainly annual grasses, than Nil endophyte pastures throughout the trial. Grazing preference, measured by the number of sheep grazing each plot, and decline in pasture height did not differ between Nil and AR542 tall fescue. Keywords: tall fescue, novel endophyte, AR542, botanical composition, weed, grazing preference

Diet selected by lambs and yearling sheep grazing on annual and perennial pastures in Southern Victoria

1967 ◽  
Vol 7 (25) ◽  
pp. 141 ◽  
Author(s):  
RW Hodge ◽  
JJ Doyle
Keyword(s):  
Nitrogen Content ◽  
Consistent Difference ◽  
Botanical Composition ◽  
Sheep Grazing ◽  
The Mean ◽  
Species Being ◽  
Clover Content

There was no consistent difference in the botanical composition or nitrogen content of the diet selected by lambs and yearling sheep grazing annual or perennial pastures in the spring. On the annual pasture, where the grass and clover content was similar, selection by the animals appeared to be random with no particular species being favoured. On the perennial pasture, where the clover content remained below 20 per cent, the mean percentage of clover in the diet selected by the lambs increased from less than 5 per cent when they were seven weeks old to over 50 per cent at 16 weeks of age. Over the same period, the mean percentage of clover in the diet selected by the yearlings increased from less than 10 per cent to over 40 per cent.

Assessment of errors in nutrient analyses of roots

Soil Research ◽  
1994 ◽  
Vol 32 (6) ◽  
pp. 1275 ◽  
Author(s):  
RK Misra
Keyword(s):  
Soil Contamination ◽  
Nutrient Concentration ◽  
Clay Soil ◽  
Nutrient Content ◽  
Nutrient Loss ◽  
Nutrient Concentrations ◽  
Root Sample ◽  
Nutrient Analyses ◽  
And Storage

Errors in nutrient analyses of roots may arise from soil adhering to roots, the method of root separation from soil and storage of root samples. Experiments were conducted on fine roots of Eucalyptus nitens from a clay soil to establish a method for estimating true concentrations of nitrogen (N), phosphorus (P) and potassium (K) in root samples (i.e. unbiased by the soil adhering to roots), and to test the adequacy of measurements of ash residues of root samples for estimating the quantity of soil adhering to roots. Results indicated that nutrient concentrations on the basis of ash-free weight of root samples approached true nutrient concentrations of roots when the quality of soil adhering to roots was small, and the nutrient concentration of soil was much lower than the roots. Estimates of true nutrient concentrations of roots calculated from the information on the weight of soil adhering to roots and the nutrient concentration of the soil were satisfactory in the prediction of nutrient content of roots for a range of soil-contamination. The factor which accounted for contamination, and helped estimation of true concentrations from measured concentrations, depended on the magnitude of soil contamination and the relative concentrations of nutrients in roots and soil. Wet separation (washing) of roots from soil compared with dry separation resulted in 24% loss of K. With various methods of storage of washed root samples, the level of soil contamination was 5-20% of the root sample. Submergence of roots in water for 15 days after washing reduced the concentration of N, P and K in roots to 84, 50 and 54% of those roots which were dried immediately following washing. The rate of nutrient loss from roots was greater for K than for N and P when washed samples were stored submerged. On the basis of this study, it is recommended that roots, after separation from soil, should be dried as soon as possible with a minimum exposure of roots to wet conditions. Estimates of soil adhering to roots, and nutrient concentration of the adhering soil, are required to infer correct concentrations of nutrients in root samples.

Effects of Low Levels of the Nutrient Content of a Food and of Nutrient Imbalance on the Feeding and the Nutrition of a Phytophagous Larva, Celerio euphorbiae (Linnaeus) (Lepidoptera: Sphingidae)

1965 ◽  
Vol 97 (1) ◽  
pp. 62-68 ◽  
Author(s):  
H. L. House
Keyword(s):  
Body Weight ◽  
Food Intake ◽  
Food Quality ◽  
Nutrient Concentration ◽  
Nutrient Content ◽  
The Body ◽  
Adequate Diet ◽  
Nutrient Imbalance ◽  
Insect Populations ◽  
Low Levels

AbstractThe present work demonstrates how important food quality is to an insect. When the dietary inadequacy in an artificial food was dilution of its nutrient content to 85, 70 and 50%, respectively, fifth-instar Celerio euphorbiae (Linnaeus) ate progressively more food but they gained no more body weight on one diet than on another. The rate of food intake depended on nutrient concentration. On all nutrient levels the larvae were about 20% efficient in converting the foodstuff into body material and the body content of protein did not differ significantly.When the dietary inadequacy was immoderate proportions of several nutrients, the effects were not so clearly marked; nevertheless, the rate of food intake of the larvae could explain their body weight. The tendency seemed to be for the larvae to eat less and to gain less weight on the imbalanced diet than on an adequate diet. Moreover, conversion of foodstuff into body material did not seem as efficient on the imbalanced diet as on the control.The ecological significance of food quality suggested by the first example is that the destructiveness of phytophagous insects, for example, may depend in part on the degree of succulence and corresponding nutrient concentration of food plant tissues; and by the second example, that perhaps nutritional imbalances may play a part in controlling the potential destructiveness of insect populations.

Effects of grazing management on botanical composition of native grass-based pastures in temperate south-east Australia

2000 ◽  
Vol 40 (2) ◽  
pp. 225 ◽  
Author(s):  
D. L. Garden ◽  
G. M. Lodge ◽  
D. A. Friend ◽  
P. M. Dowling ◽  
B. A. Orchard
Keyword(s):  
Management Strategies ◽  
Grazing Pressure ◽  
Grazing Management ◽  
Botanical Composition ◽  
Holcus Lanatus ◽  
Themeda Triandra ◽  
Continuous Grazing ◽  
Wide Range ◽  
Drought Conditions ◽  
Native Pastures

Grazing management strategies to alter botanical composition of native pastures were investigated at 4 locations in the high rainfall zone of south-east Australia, including Tasmania. These studies were conducted as part of the Temperate Pasture Sustainability Key Program, which evaluated the effects of grazing management on a wide range of pasture types between 1993 and 1996. Pastures in this study were based on Aristida ramosa/Bothriochloa macra, Microlaena stipoides–Austrodanthonia spp. or Themeda triandra–Austrodanthonia spp. Seasonal rests, increased grazing pressure in spring, mob stocking and cutting for hay were compared to continuous grazing at all sites. In addition, specific local treatments were tested at individual sites. Changes in composition resulting from the treatments were minimal at most sites. This may have been due to a combination of the inherent stability of the pastures, the relatively short duration of the experiments, and the drought conditions experienced, which minimised differences between treatments. Some strategies to alter composition of natural pastures are suggested. In the Aristida–Bothriochloa pasture there was a general decrease in Aristida and an increase in Bothriochloa, which was largely unaffected by the type of grazing management applied. The combination of drought conditions and increasing grazing pressure was sufficient to alter composition without specific management strategies being necessary. In the Themeda–Austrodanthonia pasture, resting in spring, 12-month rests or cutting for hay (which involved a spring rest) allowed Themeda to increase in the pasture. The Microlaena–Austrodanthonia pastures were very stable, especially where annual grass content was low. However, certain treatments allowed Microlaena to increase, a result which is regarded as being favourable. The major effects in these latter pastures were on undesirable species. Vulpia spp. were reduced by resting in autumn and increased spring grazing pressure, while Holcus lanatus was increased dramatically by resting in spring and was also increased by resting in autumn or winter, but only when conditions were suitable for growth of this species. In many cases, treatment differences were only expressed following recovery from drought, showing that timing of grazing management to achieve change is critical.

Variation in N, P, and K status and N efficiency in some North American willows

1990 ◽  
Vol 20 (12) ◽  
pp. 1888-1893 ◽  
Author(s):  
M. Simon ◽  
L. Zsuffa ◽  
D. Burgess
Keyword(s):  
North American ◽  
Significant Variation ◽  
Nutrient Concentration ◽  
Nutrient Content ◽  
Treatment Level ◽  
Total N ◽  
Willow Species ◽  
N Efficiency ◽  
Exponential Rates ◽  
Nutrient Solutions

Differences in N, P, and K status and N efficiency of some North American willow species and their clones were observed and evaluated. Salixeriocephala Michx., S. lucida Mühl., and S. exigua Nutt., represented by five clones each, were raised from cuttings in potted loamy sand for 113 days. Plants were subjected to three levels of fertilization (equivalent to 125, 250, or 500 kg N/ha) applied at exponential rates of addition (0.06, 0.071, and 0.082, respectively), using complete nutrient solutions and were compared with control plants (no fertilizer added). The experiment showed that nutrient concentration and nutrient uptake in the plants depended not only on treatments but also on species and clones. Thus, species and clones that removed smaller amounts of nutrients per unit of biomass could be selected. Species had a larger effect than clones on nutrient concentration and content. Total nutrient content, at the same treatment level, depended primarily on biomass production. Significant variation existed among species and clones in the ratio of biomass/total N. Salixeriocephala (the best species) produced 35.1% more than the other species, and the best experimental clones within species produced 27.8–41.6% more stem per unit of N than the poorest clones.

scholarly journals Nutrient Uptake in Poinsettia during Different Stages of Physiological Development

1997 ◽  
Vol 122 (4) ◽  
pp. 565-573 ◽  
Author(s):  
Brian E. Whipker ◽  
P. Allen Hammer
Keyword(s):  
Nutrient Uptake ◽  
Nutrient Concentration ◽  
Nutrient Content ◽  
Dry Mass ◽  
Application Rate ◽  
Plant Nutrient ◽  
Fertilizer Rate ◽  
Fertilization Rates ◽  
Total Plant ◽  
Plant Nutrient Content

`Supjibi' poinsettias (Euphorbia pulcherrima Willd.) were grown hydroponically for 15 weeks in nutrient solutions with 100-15-100, 200-30-200, or 300-46-300 (in mg·L-1 of N-P-K) to determine nutrient uptake patterns and accumulation rates. Results indicate that increasing fertilization rates from 100 to 300 mg·L-1 of N and K did not significantly influence the plant dry mass or the nutrient concentration of P, K, Ca, Mg, Na, B, Cu, Fe, Mn, Mo, and Zn in poinsettias. NH4-N concentration in the leaves, stems, and roots were lowest with the 100-mg·L-1 N fertilization rate and increased as the N application rate increased to 200 and 300 mg·L-1. Leaf P concentration levels from 1 week after potting through anthesis were above 1.3%, which exceeds the recommended level of 0.9%. When the plant tissue dry mass for each fertilizer rate was transformed by the natural log and multiplied by the mean tissue nutrient concentration of each fertilizer rate, there were no significant differences among the three fertilization rates when the total plant nutrient content was modeled for N, P, or K. Increasing the fertilizer application rate above 100 mg·L-1 N and K and 15 mg·L-1 P decreased total plant content of Ca, Mg, Mn, and Zn and increased the total plant Fe content. The results of the weekly nutrient uptake based on the total plant nutrient content in this study suggests that weekly fertilization rates should increase over time from potting until anthesis. Rates (in mg) that increase from 23 to 57 for N (with 33% of the total N supplied in the NH4-N form), 9 to 18.5 for P, 19 to 57 for K, 6 to 15 for Ca, and 3 to 8 for Mg can be applied without leaching to poinsettias and produce adequate growth in the northern United States.

scholarly journals Persistence of ryegrass, tall fescue and cocksfoot following sequential annual sowings: pasture yield, composition and density in 3 establishment years under sheep grazing in Canterbury

2018 ◽  
pp. 169-176
Author(s):  
Thomas M R Maxwell ◽  
Grant R Edwards ◽  
Gerald P Cosgrove
Keyword(s):  
Perennial Ryegrass ◽  
Tall Fescue ◽  
Block Design ◽  
Grass Species ◽  
Botanical Composition ◽  
Sheep Grazing ◽  
Sward Height ◽  
Long Term Effect ◽  
Forage Value

A long-term pasture persistence trial, consisting of repeated annual sowings, commenced in Canterbury in 2015 and is planned to continue until 2024. Preliminary results of the first 3 years sowings are reported. Each annual sowing used the same randomised block design of eight perennial ryegrass cultivars, one tall fescue and one cocksfoot cultivar, replicated four times. Grasses were drilled into a cultivated seedbed in autumn, with white clover broadcast-sown, then rolled with a Cambridge roller. Except for one 3-week spell in spring and in autumn to accumulate herbage to measure DM yield, botanical composition, morphology and sward density, plots were continuously stocked with sheep to maintain a 3-8 cm sward height from late-August to late-May. Results from the first 12 months following each of the three annual sowings (2015, 2016 and 2017) indicate establishment year had a greater influence on DM yield, botanical composition, grass leaf and stem proportions, and basal cover than did grass species or cultivar. Accumulating data from successive annual sowings and continued monitoring of each will help identify the long-term effect and difference between establishment years, as well as grass persistence traits for inclusion in the Forage Value Index ranking of perennial ryegrass cultivars.

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