Irrigated pasture productivity and its variability in the Shepparton region of northern Victoria

1983 ◽  
Vol 23 (121) ◽  
pp. 131 ◽  
Author(s):  
CR Stockdale

The seasonal distribution and variability of growth of three types of irrigated pastures were measured at Kyabram over a period of up to seven years. The pasture types studied were (1) paspalum (Paspalum dilatatum)-dominant perennial pasture, (2) ryegrass (Lolium perenne)/clover (Trifolium repens) perennial pasture, and (3) annual pasture based on subterranean clover (Trifolium subterraneum) and Wimmera ryegrass (Lolium rigidum). The influence of environmental factors on the year-to-year variability in monthly growth rates was also examined. Annual growth curves were constructed for each pasture type, and examination of the variability about each monthly mean indicated that the spring months, and October in particular, were the most variable months for pasture growth. Environmental factors were found to account for part of the year-to-year variation in pasture growth of paspalum pastures in August, September, October, November and April. Higher mean maximum temperatures significantly increased growth in September, October and April, with the greatest response occurring in October; hours of sunshine was the significant factor influencing growth in August and November. Annual pasture growth also responded to changes in mean maximum temperature or hours of sunshine in September and October. The comparative mean annual production of paspalum pasture, ryegrass/clover pasture and annual pasture was 18.3, 18.3 and 11.0 t DM/ha, respectively. These levels of production represented 1.1, 1.2 and 1.6% conversion of photosynthetically active radiation during the growing period of the three pasture types, respectively. These levels of productivity and the animal production that should result, suggest that the pasture productivity on many irrigated dairy farms is either very low or the pasture that is grown is inefficiently utilized. Because animal productivity depends on pasture productivity more than any other single factor, farmers should make improvement of pasture growth their major aim while having regard for the variability in growth that can result from variations in environmental factors.

1973 ◽  
Vol 13 (64) ◽  
pp. 549 ◽  
Author(s):  
RCG Smith ◽  
EF Biddiscombe ◽  
WR Stern

Newly sown pure swards of Wimmera ryegrass (Lolium rigidum) and subterranean clover (Trifolium subterraneum) were either grazed or spelled (deferred) for five weeks after emergence in autumn and then evaluated with young Merino wethers stocked at 10 sheep ha-1. Sheep on deferred pastures had higher intakes and liveweight than on plots continuously grazed. Spelling increased the availability of pasture for prehension due to a greater weight of herbage being offered and the more erect growth form. Under continuous grazing the animal productivity on clover was much lower than on ryegrass but following deferment, both species had similar productivity. The beneficial effects of spelling after emergence were manifest over the ensuing ten months by liveweight, fleeceweight and number of days of grazing. Spelling also increased seed reserves at the end of summer and the number of plants re-establishing at the beginning of the next growing season.


1968 ◽  
Vol 8 (35) ◽  
pp. 706 ◽  
Author(s):  
DF Smith

The effects of three grazing treatments and three mowing treatments on the dominance of barley grass (Hordeum leporinum) in an annual pasture were examined. Different spring grazing patterns did not markedly alter the amount of seed. Mowing favoured the legume component; topping less so than cutting lower as for hay or silage. However, none of these practices totally prevented barley grass from setting seed, and their effects were partly offset by late irrigation. Oversowing with subterranean clover (Trifolium subterraneum) did reduce barley grass seed setting but alone u-as not effective in changing botanical composition. Compared with Wimmera ryegrass (Lolium rigidum), barley grass showed greater persistence.


1977 ◽  
Vol 17 (89) ◽  
pp. 915 ◽  
Author(s):  
GW Arnold ◽  
SR Wallace ◽  
ESde Boer

Merino ewes lambing in March on dry subterranean-clover-Wimmera ryegrass (Trifolium subterraneum-Lolium rigidum) pastures were fed a lupin grain supplement at different rates for 10 weeks, beginning four weeks before lambing, In two experiments, birth weights of lambs were unaffected by the supplements but both milk production of the ewes and the growth rate and weaning weight of lambs increased linearly with increasing level of supplementation. At the highest rate of supplement (600 g day-1), the ewes produced 46 per cent more milk in a four hour period in the first four weeks of lactation than ewes that were not fed and their lambs were 3 kg heavier at weaning. In a third experiment in which ewes were fed in yards, increasing the protein level in the ration from 8 per cent to 14 per cent using lupin grain gave a 15 per cent increase in milk production and a significantly higher lamb growth rate at the same level of energy intake. At ad libitum levels of intake the high protein ration gave a 33 per cent higher rate of milk secretion over ten weeks and a 40 per cent higher growth rate of lambs than the low protein ration


1975 ◽  
Vol 26 (1) ◽  
pp. 137 ◽  
Author(s):  
NJ Barrow

Eleven soils which differed widely in their ability to adsorb phosphate were used in a pot trial to compare the response to phosphate by subterranean clover (Trifolium subterraneum L.) with that by Wimmera ryegrass (Lolium rigidum Gaud.). Response curves were fitted to the yields (log-transformed). The coefficients of the curves were used to calculate both the relative effectiveness of the phosphate and the phosphate required to give a given fraction of the increase in log yield due to phosphate. Overall, the phosphate requirement for the grass was less than for the clover but the two species were affected differently by the soil's ability to adsorb phosphate. The phosphate requirement for the clover increased more rapidly with increasing adsorption by the soil than the phosphate requirement for the grass.


1978 ◽  
Vol 29 (2) ◽  
pp. 225 ◽  
Author(s):  
PG Ozanne ◽  
A Petch

Three crop species, sand-plain lupin, Lupinus cosentinii L. (cv. Chapman), narrow-leaf lupin, L. angustifolius L. (cv. Uniharvest), and wheat, Triticum aestivium (cv. Gamenya), were grown under field conditions in soil fertilized then cultivated to 10 cm depth. Two annual pasture species, subterranean clover, Trifolium subterraneum L. (cv. Daliak), and Wimmera ryegrass, Lolium rigidum Gaud. (cv. Wimmera), were also grown in the field both with and without cultivation. All species were fertilized with seven levels of phosphate broadcast on the soil surface before cultivation. The amount of phosphate which produced 90% of maximum yield depended on species and cultivation practice: wheat required 98 kg phosphorus/ha; L. angustifolius, 65 kg/ha; L. cosentinii, 42 kg/ha; subterranean clover, after cultivation, 49 kg/ha; subterranean clover, not cultivated, 28 kg/ha; Wimmera ryegrass after cultivation, 40 kg/ha; Wimmera ryegrass, not cultivated, 18 kg/ha. All species except wheat required less current phosphate in this experiment than they did 3 years earlier on the same site in virgin soil. Cultivation changed the distribution of soil phosphate, and the roots of the pasture species followed the phosphate distribution.


1978 ◽  
Vol 18 (93) ◽  
pp. 539 ◽  
Author(s):  
GW Arnold ◽  
DW Barrett

In a series of five experiments, hay made by conventional methods was compared with hay made by spraying with paraquat prior to mowing. In all the experiments, chemical composition of the hays was measured and in three of them the hays were fed to sheep. In the first experiment the digestible organic matter intake (DOMI) and digestibility of oaten hay made by the two methods was similar. In the second experiment rapid desiccation was achieved using paraquat on a pasture of Wimmera ryegrass (Lolium rigidum) and subterranean clover (Trifolium subterraneum), but leaf losses during baling were higher than for turning and baling mown herbage. In the third experiment, on a densestand of Wimmera ryegrass, the stem bases were not reached by the paraquat spray and desiccation took 14 days longer than with mowing and turning. In both experiment 2 and 3 sheep consumed similar amounts of DOMIand had similar liveweight changes when fed the two types of hay, although digestibilities were lower for the hays made using paraquat. Also, in these two experiments there were higher concentrations of cell wall constituents, and in experiment 3 lower concentrations of water soluble carbohydrates (WSC), in hay made by using paraquat. In experiments 4 and 5 it was shown that large losses of WSC occurred consistently when herbage on ryegrass pastures was desiccated with paraquat. The effect was shown to occur within 24 hours of application. A further effect, that needs more research, was that the digestibility of cell wall material was lower in hay made with paraquat than in normal hay. It is concluded that the use of paraquat to provide rapid desiccation of herbage is unlikely to result in hay of higher quality than that made conventionally.


1966 ◽  
Vol 17 (5) ◽  
pp. 625 ◽  
Author(s):  
BJ Quinlivan

Hard seeds of subterranean clover (Trifolium subterraneum L.) of the Geraldton and Bacchus Marsh strains, and of West Australian blue lupin (Lupinus varius L.), were subjected to various daily fluctuating temperatures within the normal summer environmental range (15–75°C). The main factor determining the rate of softening of the hard seeds was the maxinlum temperature of the fluctuation. Provided the temperature changed by some 15°C , the amplitude of the fluctuation did not appear to be a critical factor. The softening of hard seeds of any particular species did not commence until the amplitude of the temperature fluctuation, or the maximum temperature, reached a certain level, which in turn varied with the species. Beyond this level the rate of softening increased with increasing fluctuations to a point where the rate became very rapid, and thereafter wider fluctuations or higher maximum temperatures did not give significant increases.


1968 ◽  
Vol 8 (31) ◽  
pp. 197 ◽  
Author(s):  
LF Myers ◽  
VR Squires

The effects of mowing irrigated annual pastures (Wimmera ryegrass, Lolium rigidum Gaud., and subterranean clover, Trifolium subterraneum L.) in spring for hay and of the removal of dry residues in summer were assessed by combining the operations factorially on two sites, one grass dominant, the other clover dominant. For the grass dominant sward winter yields of grass and clover in the season following mid-October mowing were respectively reduced to 43 per cent and 71 per cent of the uncut controls. In the same experiment, yields of surface seed were reduced to 24 per cent of the uncut controls. Winter yields of the clover dominant pastures were not significantly depressed except by mowing late in October. Spring yields of all treatments were similar. The tolerance of subterranean clover to cutting is discussed in relation to seed yield and the germination of above- and below-surface seed.


2019 ◽  
Vol 70 (9) ◽  
pp. 800
Author(s):  
John W. Piltz ◽  
Simon J. Flinn ◽  
Leslie A. Weston

Barley grass (Hordeum spp.) is a relatively short lived annual that provides high quality grazing early in the season, but its seed heads cause contamination of wool and carcasses, and may irritate the mouth, eyes and nose of sheep. Treatments were imposed on established subterranean clover (Trifolium subterraneum L.) annual pasture in the same plots for three consecutive years (2015 to 2017) to evaluate changes in barley grass content. Treatments included: grazing alone (G), herbicide followed by grazing (HG), or a forage conservation harvest in early October, late October or early November consistent with an early silage harvest (ES), late silage harvest (LS) or hay cut (H). Grazing plus herbicide markedly reduced (P < 0.05) barley grass numbers compared with all other treatments, but increased (P < 0.05) the growth of annual ryegrass (Lolium rigidum L.). ES reduced (P < 0.05) barley grass and increased (P < 0.05) subterranean clover compared with H, but broadleaf weed content benefitted by LS in contrast to either ES or H. Although herbicide application was the most effective method for barley grass control, forage harvest timing could be used to beneficially manipulate pasture composition.


1966 ◽  
Vol 17 (3) ◽  
pp. 303 ◽  
Author(s):  
AJ Rixon

Changes in phosphorus applied as superphosphate to irrigated pastures on a red-brown earth were studied for a 4 year period commencing 1 year after the establishment of the pastures. The pastures consisted of Wimmera ryegrass (Lolium rigidum Gaud.), perennial ryegrass (L. perenne L.), subterranean clover (Trifolium subterraneum L.), and white clover (T. repens L.). Measurements of phosphorus fractions were made on the 0–3 in. soil horizon over this period and, for the final 2 years, on the organic matter layer (mat) which was present on the soil surface under all pastures. The mat was shown to be an important accumulation site for organic phosphorus, as well as for inorganic phosphorus which accumulates from interception of broadcast applications of superphosphate. Of the 155 lb phosphorus per acre added as fertilizer, 82–100% was accounted for principally as increases in the acetic acid-soluble fraction or as organic phosphorus. There were no significant changes in the inorganic phosphorus fraction soluble in sodium hydroxide. It was concluded that the amount of phosphorus converted to the organic form will determine the level for maintenance applications of phosphorus on the irrigated pastures.


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