Liveweight and wool growth of sheep in response to the quantity and botanical composition of annual pasture induced by nitrogen fertilizer and stocking treatments

1972 ◽  
Vol 23 (6) ◽  
pp. 1101 ◽  
Author(s):  
HL Davies ◽  
EAN Greenwood
Keyword(s):  
Ammonium Sulphate ◽  
Nitrogen Fertilizer ◽  
Dry Matter ◽  
Trifolium Subterraneum ◽  
First Year ◽  
Botanical Composition ◽  
Stocking Rate ◽  
Nitrogen Concentrations ◽  
Sheep Production

For five years, three rates of ammonium sulphate (N0, N1, and N3: 0, 280, and 840 kg/ha/year) were applied as a split dressing to ,a pasture of Bromus mollis L. and Trifolium subterraneum L. which was continuously grazed by wethers set-stocked at 8.6 and 12.4 sheep/ha. The N0 treatment produced clover dominance, N1 a mixed sward, and N3 grass dominance. The higher stocking rate increased the proportion of clover in the mixed sward. These differences in botanical composition produced three significant effects on the relation between liveweight gain and quantity of green pasture on offer. An increase in the proportion of clover in the sward increased: (1) the quantity of herbage dry matter on offer required for liveweight maintenance; (2) the maximum rate of liveweight gain; (3) the quantity of dry matter on offer at the point of 90% maximum liveweight gain. Regressions of those three parameters on botanical composition accounted for over 90% of the variance. The effects of treatments on liveweight at other times of the year are also described. In the first year of grazing ammonium sulphate increased liveweight, apparently because of increased pasture on offer after emergence. In subsequent years the effect of ammonium sulphate was reversed: liveweight was reduced, and this was associated with lower nitrogen concentrations in, and lower quantities of, herbage produced. Wool elongation rates were greatest in spring and lowest prior to the germinating rains in autumn. Elongation rate was unaffected by stocking rate and only slightly affected by ammonium sulphate. From January to April, greatest elongation occurred on the grass-dominant N3 paddocks; from May to December greatest elongation occurred on the clover-dominant N0 paddocks. The implications of the role of nitrogen fertilizer in relation to sheep production in the winter rainfall regions of Australia are discussed.

Superphosphate utilization in clover ley farming. I. Effects on pasture and sheep production

1974 ◽  
Vol 25 (4) ◽  
pp. 525 ◽  
Author(s):  
GD Kohn
Keyword(s):  
Agricultural Research ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Wagga Wagga ◽  
First Year ◽  
Stocking Rate ◽  
Wool Production ◽  
Ley Farming ◽  
Hordeum Leporinum ◽  
Sheep Production

From 1962 to 1966 an experiment was carried out at the Agricultural Research Institute, Wagga Wagga, N.S.W., with dry Merino sheep on an annual clover-grass pasture, in which the stocking rate and the rates of topdressing with superphosphate were varied. In the first year Trifolium subterraneum (subterranean clover) responded to superphosphate, particularly at the lowest stocking rates. In the following 2–3 years there was a change to Hordeum leporinum Link (barley grass) dominance. A greater amount of subterranean clover persisted over the years on the unfertilized plots than on the fertilized plots. Clover burr on these treatments was associated with better liveweight performance by sheep over the dry summer-autumn period. However, after the autumn rains germinating barley grass on the topdressed plots allowed rapid liveweight gains to be made by the sheep on those treatments. Greasy wool production per head, averaged over four shearings, was 4.81, 4.36 and 3.86 kg at 5, 10 and 15 sheep per ha respectively. Superphosphate had no significant effect on wool production. Liveweights decreased as the stocking rate increased. However, at a given stocking rate, the liveweight changes were influenced by changes in pasture composition induced by topdressing with superphosphate, as much as by total available pasture. It appears that in this clover ley farming area topdressing can be omitted in the pasture phase of a wool production system after 700 kg superphosphate ha-I have been applied to the soil.

Growth of an annual pasture on virgin land in South-Western Australia including effects of stocking rate and nitrogen fertilizer

1967 ◽  
Vol 18 (3) ◽  
pp. 447 ◽  
Author(s):  
EAN Greenwood ◽  
HL Davies ◽  
ER Watson
Keyword(s):  
Ammonium Sulphate ◽  
Nitrogen Fertilizer ◽  
Growth Curves ◽  
Trifolium Subterraneum ◽  
Early Years ◽  
Stocking Rate ◽  
Virgin Land ◽  
Matter Production ◽  
Stocking Rates ◽  
Bromus Mollis

A pasture of Bromus mollis L. and Trifolium subterraneum L., sown on virgin land, was grazed by sheep for 4 years. Three rates of ammonium sulphate were factorially combined with two stocking rates. Stocking rates of 8 and 12 sheep/ha had similar effects on growth rate of the sward and influenced botanical composition only in the second and third year of grazing. Ammonium sulphate increased the proportion of B. mollis and volunteer grasses, and reduced T. subterraneum and dicotyledonous volunteers. B. mollis persisted only where ammonium sulphate was applied. T. subterraneum, in the absence of nitrogen fertilizer, was highly dominant for 3 years, then declined to 40% by the fifth year. Where nitrogen fertilizer was applied in large quantities the clover did not persist even at the higher stocking rate. The annual dry matter production of the swards which did not receive the nitrogen fertilizer was poor (c. 6000 kg/ha); the possible causes of this are discussed. Ammonium sulphate increased winter growth in the early years of the experiment. In the later years, large quantities of straw accumulated on the ammonium sulphate plots, regeneration was poor, and the nitrogen fertilizer ineffective. Growth curves of the sown species are presented and discussed.

Milk production from cows grazing on tropical grass pastures. 1. Effects of stocking rate and level of nitrogen fertilizer on the pasture and diet

1985 ◽  
Vol 25 (3) ◽  
pp. 505 ◽  
Author(s):  
TM Davison ◽  
RT Cowan ◽  
RK Shepherd ◽  
P Martin
Keyword(s):  
Protein Content ◽  
Milk Production ◽  
Nitrogen Fertilizer ◽  
Crude Protein ◽  
Dry Matter ◽  
Fertilizer Application ◽  
Stocking Rate ◽  
Crude Protein Content ◽  
Stocking Rates ◽  
Applied Nitrogen

A 3-year experiment was conducted at Kairi Research Station on the Atherton Tablelands, Queensland, to determine the effects of stocking rate and applied nitrogen fertilizer on the pasture yield and composition, diet selection by cows, and soil fertility of Gatton panic (Panicum maximum cv. Gatton) pastures. Thirty-two Friesian cows were used in a 4x2 factorial design: four stocking rates (2.0, 2.5, 3.0 and 3.5 cows/ha), each at two rates of fertilizer application 200 and 400 kg N/ha.year. The higher rate of fertilization increased the pasture green dry matter on offer at all samplings (P < 0.01); the increase ranged from 1 106 kg/ha in summer to 548 kg/ha in spring. Green dry matter decreased ( P< 0.0 1) with increasing stocking rate, with mean yields of 3736 and 2384 kg/ha at 2.0 and 3.5 cows/ha, respectively. Weed yields increased over the 3 years at the higher stocking rates for pastures receiving 200 kg N/ha.year. The crude protein content of leaf and stem increased with increasing stocking rate and amount of applied nitrogen fertilizer. Values ranged from 12.1 to 26.5% of dry matter (DM) in leaf and from 3.7 to 13.8% DM in stem. In leaf, sodium concentration (range 0.05-0.20% DM) was increased, while phosphorus concentration (range 0.21-0.44% DM) was decreased by the higher rate of fertilizer application. Plant sodium and phosphorus levels were inadequate for high levels of milk production. Dietary leaf content and crude protein contents were consistently increased by both a reduced stocking rate, and the higher rate of fertilization. Cows were able to select for leaf and at the lowest stocking rate, leaf in the diet averaged 38%; while the leaf content of the pasture was 20%. Dietary leaf content ranged from 38 to 57% in summer and from 11 to 36% in winter. Dietary crude protein ranged from 13 to 15% in summer and from 7 to 11% in winter and was positively correlated with pasture crude protein content and dietary leaf percentage. Soil pH decreased (P<0.05) from an overall mean of 6.3 in 1976 to 6.1 at 200 N and 5.8 at 400 N in 1979. Soil phosphorus status remained stable, while calcium and magnesium levels were lower (P<0.01) after 3 years.

Productivity and intensive sheep stocking over a five-year period

1967 ◽  
Vol 69 (1) ◽  
pp. 47-69 ◽  
Author(s):  
C. R. W. Spedding ◽  
J. E. Betts ◽  
R. V. Large ◽  
I. A. N. Wilson ◽  
P. D. Penning
Keyword(s):  
Milk Yield ◽  
Botanical Composition ◽  
Stocking Rate ◽  
Economic Implications ◽  
Production Processes ◽  
Percentage Weight ◽  
Grazing Systems ◽  
Sheep Production ◽  
Stocking Rates

During the last ten years or so, the management of sheep for intensive lamb production has been studied on a considerable scale, and a variety of grazing systems have been investigated (Dickson, 1959; Cooper, 1959; Spedding & Large, 1959; Boaz, 1959). It is still too soon to specify precisely the place that any of these systems should occupy in sheep-production processes, in relation to breed, lambing percentage, weight of lamb at slaughter, stocking rate, botanical composition of the pasture, size of ewe and level of her milk yield. Quite apart from these biological considerations, the full economic implications are by no means clear. What has emerged most clearly, however, is that much higher stocking rates can be tolerated than had generally been regarded as safe and that, at these stocking rates, productivity can be extremely high.

RESPONSE OF SIX-YEAR-OLD GRASS–ALFALFA PASTURES TO NITROGEN FERTILIZER IN NORTHEASTERN SASKATCHEWAN

1968 ◽  
Vol 48 (2) ◽  
pp. 167-173 ◽  
Author(s):  
D. A. Cooke ◽  
S. E. Beacom ◽  
W. K. Dawley
Keyword(s):  
Nitrogen Fertilizer ◽  
Dry Matter ◽  
Linear Increase ◽  
Bromus Inermis ◽  
Dry Matter Yield ◽  
Stocking Rate ◽  
Intermediate Wheatgrass ◽  
Nitrogen Requirement ◽  
Medicago Sativa L ◽  
N Treatment

Two 6-year-old grass–alfalfa mixtures were compared when fertilized with 0, 84 and 168 kg nitrogen per hectare and grazed by yearling Hereford steers. The effect of stocking rate, fertilization, forage mixture and year on the cumulative liveweight gain per hectare was also determined. The bromegrass (Bromus inermis L.) and alfalfa (Medicago sativa L.) mixture showed a linear increase in dry matter yield, but the nitrogen requirement of the intermediate wheatgrass (Agropyron intermedium L.) and alfalfa mixture was fully met by the 84-kg/ha N treatment. In 1960, the addition of 84 and 168 kg/ha N to the bromegrass–alfalfa increased animal production by 61 and 98% respectively. Corresponding increases of 53 and 56% were obtained from the fertilized intermediate wheatgrass–alfalfa mixture. Similar percentage increases were obtained in 1961. The 84-kg/ha N treatment reduced the alfalfa content of both mixtures by more than 40%. The 168-kg/ha N treatment practically eliminated the alfalfa from the stands. Nitrogen recovery by the bromegrass–alfalfa was similar at both fertility levels and amounted to 62% in 1960, and 24% in 1961. Recovery of nitrogen by intermediate wheatgrass–alfalfa was 62 and 36% from the 84- and 168-kg/ha N treatments in 1960, and 23 and 12% respectively in 1961.

The intensive production of herbage for crop-drying III. The effect of the continued application of nitrogenous fertilizers to grassland

1951 ◽  
Vol 41 (1-2) ◽  
pp. 64-69 ◽  
Author(s):  
W. Holmes
Keyword(s):  
Crude Protein ◽  
Dry Matter ◽  
Farmyard Manure ◽  
Seasonal Distribution ◽  
First Year ◽  
Botanical Composition ◽  
Loss On Ignition ◽  
Average Yield ◽  
Nitrogen Treatment ◽  
General Reduction

1. The experiment previously described (series 4, Holmes, 1949) on the effect of massive applications of nitrogenous fertilizers on the productivity of a ryegrass dominant pasture was continued for 3 years (1946, 1947, 1948). The manurial treatments ranged from none to the application of 312 lb. nitrogen per acre and this was applied with and without 135 lb. P2O5 and 168 lb. K2O per acre. Farmyard manure was applied to one block in 1948.2. With the heaviest nitrogen treatment plus phosphate and potash the average yield for 3 years was 8000 lb. dry matter and 1640 lb. crude protein (similar to the yield in 1946) compared with a control yield of 4720 lb. dry matter and 590 lb. crude protein. The yields declined from year to year when phosphate and potash were not applied, the decline being greatest with the heaviest application of nitrogen.3. The seasonal distribution of the yield of herbage was very considerably modified by the time when fertilizers were applied.4. The botanical composition of the swards was related to the yield, 70% of the grasses in the highest yielding sward being perennial ryegrass and cocksfoot while the lowest yielding sward contained only 35% of these grasses.5. The manurial treatments had no effect on the pH, loss on ignition or the content of readily soluble P2O5 in the soil, but in the first year there was some evidence of a general reduction of readily soluble K2O to a low level.

Effects of time and rate of paraquat application on yield and botanical composition of annual pastures containing subterranean clover in a Mediterranean climate

1973 ◽  
Vol 13 (64) ◽  
pp. 556
Author(s):  
DW Barrett ◽  
GW Arnold ◽  
NA Campbell
Keyword(s):  
Dry Matter ◽  
Mediterranean Climate ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Botanical Composition ◽  
Minimum Loss ◽  
Major Species ◽  
Nitrogen Phosphorus ◽  
Clover Content ◽  
Made In

Pastures containing subterranean clover (Trifolium subterraneum) and either Vulpia spp. or Bromus rigidus as the other major species were sprayed at 0, 0.07, 0.14 and 0.21 kg a.i. ha-1 of paraquat ion between June and early October in Western Australia. Spraying removed the grasses and produced pastures containing up to 95 per cent clover. Mid-winter applications were more effective in increasing clover content than those made in spring. These changes in botanical composition were evident in the year following spraying, but were less marked. Yields of dry matter were reduced by paraquat, especially 'in the period immediately following spraying. These losses tended to decline as the growing season progressed, but at the close they were still evident on the Bromus rigidus pasture sprayed in July. Yields at the end of the subsequent season were similar on all treatments. Paraquat applied in mid-August at 0.14 kg a.i. ha-1 to both pastures produced the greatest change in botanical composition with the minimum loss of yield. The concentrations of nitrogen, phosphorus, calcium and magnesium were higher in mature herbage on paraquat treatments. Total yields of nutrients were similar between treatments because of reduced dry matter yield.

Superphosphate and stocking rate effects on a native pasture oversown with Stylosanthes humilis in central coastal Queensland. 1. Pasture production

1978 ◽  
Vol 18 (95) ◽  
pp. 788 ◽  
Author(s):  
NH Shaw
Keyword(s):  
Soil Phosphorus ◽  
Total Yield ◽  
Botanical Composition ◽  
Stocking Rate ◽  
Pasture Production ◽  
Average Percentage ◽  
Heteropogon Contortus ◽  
Native Pasture ◽  
Nitrogen Concentrations ◽  
Stocking Rates

Changes in the yield, botanical composition and chemical composition of a native pasture (Heteropogon contortus dominant) oversown with S. humilis (T.S.) were measured in a grazing experiment from 1966 to 1973. The 24 treatments were factorial combinations of two sowing methods for T.S. (ground sowing into spaced cultivated strips, or aerial sowing), three levels of molybdenized superphosphate (F0 = nil ; F1 = 125 kg ha-1 annually; F2 = 250 kg ha-1 annually plus an extra 250 kg ha-1 initially) and four stocking rates. Stocking rates were gradually increased during the experiment and for the last three years overlapping ranges were used for the three fertilizer levels; the overall range was then from 0.55 to 1.65 beasts ha 1 T.S. establishment by ground sowing was much more reliable than from aerial sowing, giving twice the average percentage frequency, and this proportion was maintained over years. High fertilizer improved establishment and the best legume stands were in the high fertilizer high stocking rate treatments. Total presentation yield of pasture was increased by fertilizer and reduced by high stocking rates. Over the last two years the means for March, adjusted by regression to the overall average stocking rate of 0.98 beasts ha-1, were 31 20,4020 and 5370 kg ha-1 for F0, F1 and F2 respectively, but these yields were reduced by ca 25 per cent for an increase of 0.5 beasts ha-1. H. contortus remained dominant and its mean contribution to total yield increased from 48 per cent in 1969 to 67 per cent in 1973. This proportion was reduced by 12.8 per cent over the range from 0.55 to 1.65 beasts ha-1, but high fertilizer had the opposite effect so that differences between the extremes low stocked F0 and high stocked F2 were small. The DM percentage yield of T.S. was strongly increased by fertilizer, and, most importantly, also by high stocking rates in the presence of fertilizer. Values for F0 treatments remained below 10 per cent, but in the final year values for F1 and F2 at the highest stocking rates were 36 and 27 per cent, respectively. Despite these large changes in T.S., there was overall stability of botanical composition. Phosphorus and nitrogen concentrations in T.S. and H. contortus were increased by superphosphate but there was an overall decline in potassium concentration. Soil phosphorus levels were greatly increased

Effect of fertilizer nitrogen, stocking rate and autumn deferment of grazing in association with hay cutting on the root structure of annual pasture species

1976 ◽  
Vol 16 (78) ◽  
pp. 110 ◽  
Author(s):  
JJ Doyle ◽  
MJ Sharkey
Keyword(s):  
Nitrogen Fertilizer ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Grazing Pressure ◽  
Stocking Rate ◽  
Root Structure ◽  
Root Branching ◽  
Grass Roots ◽  
Hordeum Leporinum ◽  
Main Components

Length, weight, branching and chemical composition of roots of barley grass (Hordeum leporinum) and subterranean clover, (Trifolium subterraneum), the main components of a non-irrigated pasture were measured in the fourth year of an experiment on pastures grazed by Corriedale wethers. The grazing treatments were in a factorial design (2 x 2 x 3) replicated three times, with three stocking rates, two levels of nitrogen fertilizer and two methods of management. Grass and clover density was reduced progressively as stocking rate was increased from 10 to 12 to 17 wethers ha-1 but the surviving plants at maturity had vigorous root systems. This performance of annual species contrasts with that of perennial pasture species where root development and root branching may be expected to decline with increase in grazing pressure. Applications of nitrogen fertilizer annually at rates of 0 or 67 kg ha-1 had little effect on density of grasses or clovers but clover roots were lighter and had fewer rhizobia nodules where nitrogen fertilizer had been applied. The management of pasture by deferment of grazing during regeneration was beneficial to clover plants in that their root structure was larger at maturity; similar effects were not evident in grass roots.

A relation between wool production per animal and annual pasture dry matter production per animal

1982 ◽  
Vol 33 (4) ◽  
pp. 705 ◽  
Author(s):  
BA Rowe
Keyword(s):  
Dry Matter ◽  
Simple Relation ◽  
Dry Matter Production ◽  
First Year ◽  
Stocking Rate ◽  
Pasture Production ◽  
Wool Production ◽  
The Third ◽  
Matter Production ◽  
Curvilinear Relation

A simple relation between the annual wool production per animal (y) and the amount of pasture dry matter produced per animal (x) was derived and tested using the results from a grazing experiment in which the effects of superphosphate and stocking rate on wool and pasture dry matter production were measured from pastures which were continuously grazed by Merino wethers for 3 years. The linear relation, y = a + b/x, accounted for 63% of the variance in wool production per animal in the first year, 82 % in the second and 97 % in the third. Exclusion of an outlier from the first year results increased the variance accounted for to 85 %. This model is simpler and more precise than some others that have been published. It is also consistent with the curvilinear relation between production per animal (y) and pasture production per animal (x).

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