Effects of superphosphate application and cutting interval on native pastures in the Clarence Valley, New South Wales

1978 ◽  
Vol 18 (94) ◽  
pp. 718 ◽  
Author(s):  
DL Garden ◽  
DR Brooks ◽  
J Bradley

The effects of superphosphate rate (nil; 250 kg ha-l initial with 125 kg ha-1 maintenance; and 500 kg ha-1 initial with 250 kg ha-1 maintenance) and cutting interval (2, 4, 6 or 8 weeks) on dry matter yield, growth rate, botanical composition and chemical composition of native pastures on a sandstone soil in the Clarence Valley, New South Wales were studied over a period of three years. Mean annual dry matter yield of unfertilized native pasture was 990 kg ha-l and this was increased to 1322 kg ha-1 at the higher rate of superphosphate. Dry matter yield was depressed from 1587 to 647 kg ha-1 by decreasing cutting interval from 8 weeks to 2 weeks. Pasture growth was limited to the September to May period and 87 per cent of the total annual production occurred in summer and autumn. Maximum growth occurred in the February/March period, with 16.2 kg ha-1 day-1 being the maximum recorded for the unfertilized pasture and 19.9 kg ha-1 day-1 for pasture at the higher rate of superphosphate. Changes in botanical composition were neither large nor consistent. Phosphorus content of the native pasture averaged 0.12 per cent. Crude protein content averaged 7.4 per cent, with levels in standing herbage in winter-spring falling to 3 per cent. Phosphorus yield was 1.1 kg ha-1 year-1 and crude protein yield was 65.8 kg ha-1 year-1. Superphosphate increased phosphorus content and yield, and crude protein yield. Increasing cutting interval decreased phosphorus and crude protein contents but increased phosphorus and crude protein yields by its effect on dry matter yield. Maximum yields obtained were 3.3 kg ha-1 year-1 phosphorus and 100 kg ha-1 year-1 crude protein. It was concluded that the increases obtained would be insufficient to produce worthwhile improvements in animal production, and that an increase in the legume content of these pastures is required before this could occur.


1986 ◽  
Vol 26 (2) ◽  
pp. 165 ◽  
Author(s):  
GM Lodge

Three irrigated lucerne cultivars, Pioneer Brand 545 (winter dormant), Condura 73 Brand (semiwinter dormant), and CUF 101 (highly winter active), were harvested at fixed cutting intervals of either 25, 28 ,35, 42 or 48 days from September to April in each of four years. This paper reports the effects of these cutting frequencies on the dry matter yield, leaf to stem ratio and persistence of these cultivars. The effect of cutting frequency on mean total yield (the sum of the mean yields for each harvest) was significant (P<0.05) in each year of the experiment, except year 3. Yields were highest in the 35-day cutting frequency in years 1 and 2. In the fourth year of the experiment the mean total yield of Pioneer Brand 545 and Condura 73 Brand was 29% higher (P<0.05) than CUF 101. By the fourth year substantial amounts of grass were present in the 25- and 28-day cutting interval plots. The contrasts between dormant and active cultivars for the dry matter yield of each of the individual harvests were not consistent in the first two years. In the third and fourth years the active initially outyielded the dormant cultivars at all cutting intervals, but yields of both were generally similar at the end of the season. Increasing the interval between successive harvests generally decreased the mean leaf to stem ratio. The ratio of leaf to stem for CUF 101 was significantly lower (P<0.05) than that for Pioneer Brand 545, with Condura 73 Brand tending to be intermediate. Within cutting intervals, mean declines in plant persistence were similar for cultivars from the different dormancy groups. Largest changes in plant frequency occurred in the fourth year when the mean frequency for the 25- and 28-day plots decreased from 69 to 12% compared with a mean decline from 74 to 65% for the 42- and 48-day cutting intervals. Productive stand life in this experiment was 3 years, even though disease was negligible. Under these conditions grass invasion was mainly related to harvest interval and much less to cultivar dormancy.



1963 ◽  
Vol 3 (8) ◽  
pp. 26 ◽  
Author(s):  
MJT Norman

A report is given of the first five years of an experiment at Katherine, N.T., concerned with the effects of time and frequency of burning on the dry matter yield, nitrogen yield and botanical composition of native pasture on Tippera clay loam. Sampling in 1961-62 showed that all burning treatments reduced dry matter yield in comparison with unburned pasture Pasture burned biennially in the late dry season (September) showed the least reduction in yield. Biennial burning was less detrimental than annual burning ; burning in late dry season was less detrimental than burning in early dry season. Burning in late dry season increased the proportion of annuals in the pasture. All treatments other than biennial burning in late dry season reduced the proportion of Themeda australis (R. Br.) Stapf., the dominant perennial grass. Burning biennially in January or in April increased the proportion of Chrysopogon fallax, S. T. Blake. The provisional recommendation for Themeda-Sorghum pastures in the Katherine area is to bum in late dry season at intervals of not less than two years.



1991 ◽  
Vol 42 (3) ◽  
pp. 379 ◽  
Author(s):  
MK Conyers ◽  
MK Conyers ◽  
GJ Poile ◽  
GJ Poile ◽  
BR Cullis ◽  
...  

Twenty-three surface soils (0-10 cm) sampled from major New South Wales lime trials were incubated at six lime rates, from 0 to 10 t/ha, and used in pot trials with barley (Hordeurn vulgare cv. Schooner) which was grown for five weeks. Each replicate pot was soil tested for exchangeable cations (Ca, Mg, K, Na, Mn, Al), pH in 0.01 M CaCl2, and Al in the 0.01 M CaCl2 extract by pyrocatechol violet (total Al) and by reaction for 15 s in 8-hydroxyquinoline (monomeric Al). The latter was also converted to the activity of Al3 in the 0.01 M CaCl2 extract. The soil tests were compared for their prediction of the dry matter yield of whole tops of barley. The four tests for aluminium (exchangeable Al as Al/ECEC; total 0.01 M CaCl2 extractable Al; monomeric 0.01 M CaCl2 extractable Al; and Al3+ activity in 0.01 M CaCl2) were each better indicators of the infertility of the acid soils than soil pH. The prediction of the dry matter yield of barley by the four aluminium tests was improved by the inclusion of exchangeable soil manganese in the statistical analysis. The use of 0.01 M CaCl2 is recommended as a routine extraction procedure for diagnosing Al toxicity. Soil Mn should also be measured and included in correlations with barley growth. Pyrocatechol violet is the recommended analytical procedure for Al owing to its comparative simplicity.



1966 ◽  
Vol 6 (23) ◽  
pp. 388 ◽  
Author(s):  
RL Colman

A factorial field experiment, comparing three rates of nitrogen as anhydrous ammonia, two seeding rates of oats, and the presence or absence of a herbicide applied to grass pastures before sod-seeding, was conducted at Kyogle, New South Wales in 1964. Plots were sown in mid-autumn and harvested in winter and early spring. Increased applications of nitrogen and the higher seeding rate increased both dry matter yield and total nitrogen content. Application of herbicide significantly increased yield at the low rates of nitrogen but not at the highest rate. Anhydrous ammonia at 120 lb of nitrogen an acre had no effect on the germination of oats seed and provided adequate nitrogen for growth of oats without the need for herbicide application or cultivation of the grass pasture. The results suggest that oats can be successfully sod-seeded into grass dominant pastures by using 120 lb of nitrogen as anhydrous ammonia and four bushels of oats an acre.



1973 ◽  
Vol 13 (64) ◽  
pp. 567 ◽  
Author(s):  
EC Wolfe ◽  
A Lazenby

The effects of superphosphate (0, 42, 125, and 375 kg ha-1 year-1), grass species (tall fescue, perennial ryegrass, and phalaris) and grass seeding rate (0, 1.1, 4.5, and 17.9 kg ha-1) on the productivity and botanical composition of grass-white clover pastures were investigated from 1967 to 1970 on a previously unfertilized site at Armidale, New South Wales. In all years, total pasture yields were increased by each additional increment of superphosphate applied. During the establishment year, the addition of 375 kg ha-1 superphosphate increased clover dry matter yield by more than 3500 kg ha-1, whereas grass production was low (< 1500 kg ha-1) on all treatments. Thereafter, the increases in grass yields at each level of superphosphate were the equal of, or exceeded, the clover responses, which were mainly linear throughout the experiment. Neither grass seeding rate nor grass species had a major effect on total pasture productivity. Their effects on the relative yields of the grass and clover components were most evident at the highest rate of superphosphate. At SP0, grass and clover percentages declined from 1967 to 1970 and at SP125 the proportions of grass, clover and weeds were about equal in all years. At SP375, the strong overall trend from clover-dominance in 1967 to grass-dominance in 1970 was most rapid in treatments sown with 4.5 or 17.9 kg ha-1 grass and least rapid in phalaris-white clover pastures. In 1969 and 1970, when most pastures at SP375, had reached the grass-dominant stage of their development, within-year fluctuations in grass and clover content were least in the fescue-white clover pastures.



1994 ◽  
Vol 34 (6) ◽  
pp. 753 ◽  
Author(s):  
GM Lodge ◽  
MG McMillan ◽  
AJ Schipp ◽  
AS Cook

Two experiments were conducted at Tamworth, New South Wales, to assess the effects of herbicides applied post-sowing pre-emergence, and at 2 post-emergence growth stages, on Danthonia (wallaby grass) dry matter yield, plant number, and plant phytotoxicity. Phytotoxicity was scored visually on a 0-5 scale (0, no phytotoxicity; 5, 100% phytotoxicity). In the post-sowing pre-emergence study, no Danthonia plants survived on plots sprayed with metribuzin (375 g a.i./ha), chlorsulfuron (45 g a.i./ha), or simazine (750 and 1500 g a.i./ha). Phytotoxicity was also high at lower rates of metribuzin (187.5 g a.i./ha) and chlorsulfuron (22.5 g a.i./ha). Dry matter yields and plant numbers on 2,4-D amine and ester treatments were not significantly different from those of unsprayed controls. On metsulfuron-methyl (3 and 6 g a.i./ha) and triasulfuron (21.4 g a.i./ha) treatments, plant numbers were similar to the controls, but Danthonia yields were lower (P<0.05). In seedling stands, the only herbicide that reduced (P<0.05) Danthonia dry matter yield compared with the unsprayed control plots was metsulfuron-methyl applied at 6, 12, and 18 g a.i./ha at the 2-4 tiller stage, and at 12 and 18 g a.i./ha at early stem elongation. At both times of application, Danthonia plant numbers were lowest (P<0.05) on the metsulfuron-methyl 12 and 18 g a.i./ha treatments. Phytotoxicity scores were >2 and highest (P<0.05) on all metsulfuron-methyl plots. These studies indicated that a range of chemicals could be used to control broadleaf weed seedlings, without damaging Danthonia seedlings.



1974 ◽  
Vol 14 (69) ◽  
pp. 526 ◽  
Author(s):  
HJ Fisher

Three rates of nitrogen fertilizer and a standard superphosphate dressing were applied to a Themeda australis grassland with and without broadcast seed of Dactylis glomerata. Two cutting frequencies were imposed and dry matter yields and botanical composition were measured. T. australis responded to nitrogen, but the response was not sufficient for it to predominate over other species, particularly Poa labillardieri, as it had done under low fertility conditions. P. labillardieri yields increased markedly with increasing nitrogen rate. D. glomerata, which established only where nitrogen fertilizer was applied, substantially reduced the increase in P. labillardieri at the high level of nitrogen. Cutting frequency affected botanical composition in degree but not in kind. Both P. labillardieri and D. glomerata yielded less, but T. australis yielded more under more frequent cutting. For pasture improvement in wetter parts of the southern tablelands of New South Wales, it is important to establish a perennial grass at the beginning of the programme to reduce the growth of the undesirable tussock. P. labillardieri.



1994 ◽  
Vol 34 (6) ◽  
pp. 759 ◽  
Author(s):  
GM Lodge ◽  
MG McMillan

Three experiments were conducted at Tamworth, New South Wales, in 1990-92 to assess the effects of a range of broadleaf and grass herbicides, 6 rates of glyphosate and paraquat + diquat, and 4 rates of 2,4-D amine and diuron on the phytotoxicity, dry matter yield, inflorescence number, and seed yield of established Danthonia (wallaby grass) plants. Phytotoxicity was scored visually on a 0-5 scale (0, no phytotoxicity; 5, 100%). Danthonia dry matter yields were not affected (P<0.05) by any herbicide tested, except glyphosate applied at 2360 g a.i./ha. Phytotoxicity was highest for the glyphosate treatment (1440 g a.i./ha) in that study. All rates of glyphosate, and paraquat + diquat rates >250 + 150 g a.i./ha reduced (P<0.05) inflorescence number compared with the unsprayed control. Paraquat + diquat had no significant effect on seed yield, but glyphosate rates >360 g a.i./ha reduced (P<0.05) seed yield compared with the control. In 1992, no damage was observed on 2,4-D amine treatments and phytotoxicity scores were low (<2) for all diuron treatments. Danthonia inflorescence numbers and seed yields were higher (P<0.05) on plots mown in early spring than on unmown treatments. The lack of effect of herbicides such as diclofopmethyl, simazine, fenoxaprop-ethyl, and diuron on Danthonia dry matter yield, and the low phytotoxicity, indicated that a range of chemicals may be used on established Danthonia swards to control perennial and annual grass weeds. Seed yield was more affected than dry matter yield by herbicide, and paraquat + diquat should be used in preference to glyphosate on seed crops.



1976 ◽  
Vol 16 (82) ◽  
pp. 630 ◽  
Author(s):  
JP Langlands ◽  
JE Bowles

The potential for nitrogen (N) supplementation of ruminants grazing native pastures in late winter was examined in two experiments. In experiment 1 the N contents of the diet selected by unsupplemented sheep and cattle, and by cattle receiving a supplement of linseed meal were determined. Dietary composition was not affected by supplementation but sheep selected a diet averaging 1.7 gN/100 g OM which was significantly greater than the corresponding value of 0.96 gN/100 g OM for cattle. Differences in dietary composition between sheep and cattle were also evident in experiment 2 and were confirmed by analysis of rumen liquor. It was concluded that sheep would not respond to non-protein N supplementation but that cattle might be marginally N deficient. In experiment 2 groups of heifers grazing native pasture were offered supplements of either molassesurea containing 2.54 gN/100 g OM, molasses-urea containing 7.66 gN/100 g OM, linseed meal containing 6.64 gN/100 g OM, or linseed meal treated with formaldehyde. Liveweight changes relative to an unsupplemented group were determined, and individual consumptions of supplement were measured using tritiated water. All heifers lost weight and the rate of loss was significantly greater in unsupplemented heifers than in those receiving supplement. Differences between supplemented groups were not significant after liveweight losses had been adjusted to equal energy intakes using covariance analysis.



1999 ◽  
Vol 39 (6) ◽  
pp. 685 ◽  
Author(s):  
G. M. Lodge ◽  
B. J. Gogel ◽  
K. A. Archer ◽  
B. R. Cullis

Summary. Studies were conducted on a natural pasture dominated by Aristida ramosa (wiregrass) in northern New South Wales. In each of the 4 studies, treatments were designed to reduce wiregrass presence by grazing, using stocking rates up to 12.5–15.0 dry sheep equivalents (dse/ha) in summer and autumn (1983–88), slashing (1984–86), or burning (2 studies, 1985–88; 1986–88) in spring before heavily grazing in summer–autumn. Effects of these treatments on A. ramosa dry matter yield and basal cover, Danthonia linkii (wallaby grass) basal cover, sheep liveweight change and fleeceweight were measured for the different time periods. Wool quality was determined from mid-side samples taken in 1983–85. All treatments reduced A. ramosa dry matter yield and basal cover and increased D. linkii basal cover, compared with control plots continuously grazed at 5 dse/ha. From 1983 to 1988, A. ramosa dry matter yields in the control plots increased from about 1000 to 3500 kg/ha and its basal cover increased from 7 to 13%. In contrast, A. ramosa dry matter yields in heavily grazed, and spring burnt and heavily grazed treatments were <500 kg/ha, with basal cover levels of A. ramosa <0.3% while those of D. linkii were about 5%. Slashing before heavy grazing (1984–86) also reduced A. ramosa dry matter yields and basal cover compared with the control, but higher levels of A. ramosa (800 kg/ha dry matter, 1% basal cover) remained at the end of these studies. Heavy grazing of wiregrass led to significant negative liveweight changes, compared with sheep in control plots. Slashing or burning of wiregrass to remove dead material and increase green leaf before grazing at high stocking rates, markedly reduced rates of liveweight decline. Both grazing at high stocking rate and slashing in spring followed by heavy grazing, significantly reduced the amount of wool grown in the spring–winter period and significantly decreased either wool fibre diameter, strength or point-of-break. In the long term, sheep in wiregrass control plots lost more weight than those in treatment plots at equivalent stocking rates. Results suggest that on-farm control strategies based on late winter or spring burning, and heavy summer grazing should reduce the presence of wiregrass in similar pasture system.



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