Establishment and development of surface sown pasture species in a nitrophilous weed association: effect of herbicide rate

1981 ◽  
Vol 21 (112) ◽  
pp. 531 ◽  
Author(s):  
MH Campbell ◽  
AR Gilmour ◽  
DT Vere

In an experiment carried out between 1976 and 1979 near Orange, New South Wales, the effects of four rates of glyphosate (0.1 25, 0.25, 0.5 and 1.0 kg/ha active ingredient (a.i.)) and three rates of amitrole (0.5, 0.75, 1.0 kg/ha a.i. in association with 2.5 kg/ha a.i. 2,2-DPA) on the suppression of a nitrophilous weed association (broadleafed plants, annual grasses, native perennial grasses, annual legumes) and the resultant establishment and development of surface sown pastures species (Medicago sativa, Phalaris aquatica, Dactylis glomerata, Festuca arundinacea) were measured. The length of weed suppression in the year of spraying (1976) was the most important factor in the eventual development of the sown species. Glyphosate at 1.0 kg/ha a.i. gave better weed suppression for longer (up to and beyond 23 weeks after spraying) than any other herbicide treatment and allowed sown species to establish and survive the first summer better and thus produce a better pasture three years later. Weed suppression between 8 and 19 weeks after spraying affected the initial establishment of sown species; in general, establishment was better on herbicide treatments that reduced ground cover of the weed association to less than 30% in this period. Rate of weed suppression had no effect because no sown species germinated in the eight weeks after spraying. Three years after treatment the ground cover of the nitrophilous weed association was 31% on the best herbicide treatment (glyphosate, 1.0 kg/ha a.i.) and 83% on the unsprayed control; the respective ground cover of sown species was 60% and 7%. The increase in ground cover of sown species during the three years was on most treatments almost entirely due to the increase in basal area of P. aquatica.


1986 ◽  
Vol 26 (3) ◽  
pp. 331 ◽  
Author(s):  
MH Campbell ◽  
MJ Keys ◽  
RD Murison ◽  
JJ Dellow

The effects of time and rate of application of glyphosate, 2,2-DPA and tetrapion on Poa labillardieri and Themeda australis were measured in seven experiments carried out 55 km south of Braidwood, on the southern tablelands of New South Wales between 1980 and 1982. In an eighth experiment (1981) and in a 35-ha demonstration (1983), at the same site, the effects of applying herbicides (before and after the autumn break) and surface-sowing Phalaris aquatica, Festuca arundinacea and Trifiolium repens with fertiliser on the control of P. labillardieri were ascertained. All three herbicides proved effective in reducing the ground cover of P. labillardieri from applications at any time of the year. For T. australis, tetrapion proved effective when applied at any time of the year, while glyphosate and 2,2-DPA were effective in all seasons except winter. Glyphosate at rates between 0.72 and 1.44 kg/ha a.i. was more cost effective than 2,2-DPA (11.1 kg/ha a.i.) and tetrapion (3.75 kg/ha a.i.). Best establishment and development of sown grasses and legumes was attained by applying herbicides after the autumn break but before heavy frosts, and then surface-sowing 1-3 months later. Control of P. labillardieri was best where P. aquatica and F. arundinacea established most densely.



2005 ◽  
Vol 45 (12) ◽  
pp. 1603 ◽  
Author(s):  
G. M. Lodge ◽  
L. H. McCormick ◽  
S. Harden

Hyparrhenia hirta (L.) Stapf (Coolatai grass) has invaded large areas of grazed native grasslands on the North-West Slopes of New South Wales (NSW) and is widespread along roadsides and travelling stock routes. It is commonly regarded as an invasive, weedy species with low forage value when it is tall and rank, but may be more palatable when kept short, green and leafy. A study (1990–2001) of a naturalised stand of Coolatai grass in the Manilla district of northern NSW examined its herbage mass (kg DM/ha), persistence (basal cover %), and grazing value under 2 contrasting grazing treatments: pastures that had either large amounts of dry, unpalatable herbage [light grazing at 5 dry sheep equivalents (DSE)/ha] or were short, green and leafy (strategic heavy grazing at a stocking rate of 37 DSE/ha). Effects of pre-grazing treatments (slashing, burning, and no defoliation) were also examined and data (litter mass, plant basal area, ground cover, and soil and litter microbial carbon and nitrogen) collected to assess the long term sustainability of these grazing systems. Sheep grazed the light grazing treatment for about 34% of the experimental period, with the strategic heavy grazing treatment being grazed for about 7% of the time. Over the experimental period this equated to 6752 DSE grazing days/ha for the light grazing treatment compared with 10 120 DSE for the heavy grazing treatment. Herbage mass in the heavy grazing treatment declined to <1000 kg DM/ha within 6 months of the start of grazing and remained below this level until December 1998 when stocking rates were switched (i.e. plots previously grazed at low stocking rate were subjected to the heavier rate and vice versa). In contrast, mean herbage mass in the light grazing treatment was generally >3000 kg DM/ha from November 1990–98, but a high proportion of this was dead standing material that carried over from season to season. Mean Coolatai grass basal cover was 9.5% in November 1990, increasing over time to about 25% in both grazing treatments by December 2000. Coolatai grass herbage accumulation was highly seasonal, ranging from as high as 70 kg DM/ha.day in summer to 0 in winter. In both grazing treatments, forage quality was low for both green and dead material, with mean crude protein being 6.0 (green) and 3.4% (dead). Digestible dry matter values ranged from 41 to 62% (green) and 32 to 51% (dead) and mean metabolisable energy values were 7 (green) and 5.3 MJ/kg DM (dead). After 8 years, the heavy grazing treatment had lower (P<0.05) litter mass, ground cover, plant basal area and soil microbial C and N levels than the light grazing treatment, but switching of the stocking rates restored most indicators, except the soil microbial values.



1979 ◽  
Vol 19 (99) ◽  
pp. 448 ◽  
Author(s):  
MH Campbell ◽  
WJ McDonald

In an experiment (1974 to 1978) carried out on the Central Tablelands of New South Wales, the effects of nine herbicide treatments, two intervals between spraying and sowing, and sowing in late autumn, on the ability of Medicago sativa, Phalaris aquatica and Vicia dasycarpa to establish, develop and replace a nitrophilous weed association (broadleafed plants, annual grasses and native perennial grasses) were measured. Herbicide treatment of the resident species was necessary for the establishment and development of M. sativa and P. aquatica but not for the establishment of V. dasycarpa. Successful treatments were: 2,2-DPA + amitrole, 2,2-DPA + 2,4-D, paraquat + diquat and glyphosate. Intervals of 7 and 28 days between spraying and sowing had no differential effect on establishment. Sowing in late autumn resulted in successful establishment of all species. Over four years the percentage ground cover of sown species on the herbicide treatments increased from 0% in early 1974 to 49% in late 1978; the control treatment rose from 0% to 12%. The percentage ground cover of the nitrophilous weed association on the herbicide treatments decreased from 76% in 1974 to 27% in 1978; the control fell from 76% to 68%. The experiment demonstrated that a nitrophilous weed association can be replaced with perennial pasture species on non-arable land on the Central Tablelands by using aerial techniques. Further research is needed to determine the optimum time of spraying and sowing.



1996 ◽  
Vol 18 (2) ◽  
pp. 309 ◽  
Author(s):  
PM Dowling ◽  
DR Kemp ◽  
DL Michalk ◽  
TA Klein ◽  
GD Millar

The influence of grazing management, herbicide and fertiliser on botanical change in two perennial grass based pastures was assessed over six years at two sites in central New South Wales. Ten treatments at both sites compared continuous grazing, three seasonal rests from grazing (autumn, winter, summer), and herbicide application for seedling grass control, each at two levels of fertiliser addition (nil, recommended). These treatments were designed to screen options for management rather than devise complete systems. In a degraded perennial pasture dominated by annual grasses, the proportion of perennial grasses and forbs increased with summer rests, especially at the recommended fertiliser level. Legumes increased with herbicide application, and annual grasses remained high in the continuously grazed control and other treatments. There were no significant effects on composition from autumn or winter rests. On the summer rest treatment at the recommended fertiliser level, perennial grasses (mostly cocksfoot) increased from 11% to 30% compared with the control where perennial grass declined below 5%. The increase was due to both recruitment and increase in size of existing plants, as a consequence of resting the perennial grasses when actively growing, flowering and setting seed, in favourable seasons. In contrast, on the better quality perennial pasture dominated by phalaris, there were limited management effects and perennial grasses increased on all treatments over time. The absence of a response at this site was attributed to a lenient stocking rate, dominant perennial grasses and limited rainfall during periods when active growth might be expected. Summer rests in this case also led to a small increase in forbs. The data suggest that perennial grasses can be encouraged with a conservative stocking policy that maintains the available feed-on-offer above 1 t DM/ha through seasons of active growth.



2003 ◽  
Vol 43 (8) ◽  
pp. 891 ◽  
Author(s):  
G. M. Lodge ◽  
S. R. Murphy ◽  
S. Harden

As part of the Sustainable Grazing Systems (SGS) National Experiment a study was conducted on a native pasture in the Manilla district of northern New South Wales to examine the effects of 5 grazing treatments on total herbage mass, litter mass, basal cover, ground cover, sheep liveweight, wool production and soil water content (SWC, mm) at different depths. The pasture was a mixture of native perennial grasses, with redgrass (Bothriochloa macra) and wiregrass (Aristida ramosa) dominant on a red Chromosol soil type and bluegrass (Dichanthium sericeum) on a brown Vertosol. Wallaby grasses (Austrodanthonia richardsonii and A. bipartita) were common on both soils. Plots were grazed with Merino wethers and data collected from spring 1997 to spring 2001 were analysed to determine the effect of treatments on both production and sustainability. Five grazing treatments were applied in a randomised 3 replicate design. Grazing treatments were: continuous grazing at 3.1 and 6.2�sheep/ha (C3 and C6), continuous grazing at 9.2 sheep/ha, with subterranean clover (Trifolium subterraneum) oversown and fertiliser applied (C9+sub) and rotational grazing at an annual stocking rate of 3.1 sheep/ha with pasture grazed for 4 weeks and rested for 4 weeks (R4/4), or rested for 12 weeks (R4/12). Over time, treatments had no significant effect on either total pasture herbage mass (compared with the C3�control) or the basal cover of the major perennial grasses. Treatments had inconsistent significant effects on ground cover, litter mass, sheep liveweight and wool production (kg/head) over time. Compared with all other treatments ground cover was less (P<0.05) in the C6 treatment in only May and September 2000 and litter mass less (P<0.05) in only December 1998 and March 1999. Treatment sheep liveweights were not significantly different from the C3 treatment from September 1997 to 1999. However, from October 1999 to October 2001 sheep liveweight in the C6 treatment was significantly less than in the C3 treatment, while in the C9+sub and R4/12 treatments it was significantly greater than the control. In 1999, wool production per head was higher (P<0.05) in the C9+sub and R4/12 treatments compared with all other treatments but treatment differences were not significant in all other years. Significant differences in SWC only occurred at the 0–30 cm depth between the C3 and the C6 and R4/12 treatments, but were predicted to be <1.5 mm/year. A sustainability index derived from economic [equivalent annual net return ($/ha) for a 10-year period], animal production, pasture, soil health and soil water data indicated that the overall indices were lowest for the C3, C6 and C9+sub treatments and highest for the R4/4 and R4/12 treatments.



2004 ◽  
Vol 55 (3) ◽  
pp. 345 ◽  
Author(s):  
G. M. Lodge

A series of seed and seedling studies was undertaken in northern New South Wales for the temperate perennial grasses phalaris (Phalaris aquatica cv. Sirosa and Australian), tall fescue (Festuca arundinacea cv. Demeter), perennial ryegrass (Lolium perenne cv. Kangaroo Valley), and 2 wallaby grasses (Austrodanthonia bipartita syn. Danthonia linkii cv. Bunderra and A. richardsonii syn. D. richardsonii cv. Taranna). Studies were conducted to determine the level of dormancy in freshly harvested seed and the time required to overcome it, effects of alternating daily temperatures on the germination of non-dormant seed, effect of time-of-sowing on seedling emergence (2 studies) and survival, levels of seed production and soil seedbanks, and the effect of litter cover and soil type on the emergence of Sirosa phalaris seedlings.Grass species, time, and their interaction all had a significant effect (P < 0.05) on both dispersal unit and caryopses germination. One month after harvest, germination of caryopses was lower (P < 0.05, 2 and 1%, respectively) for Taranna and Bunderra than for Sirosa (79.5%). In March 1993, germination of the 2 wallaby grasses was also lower (P < 0.05) than that of Sirosa. Dormancy of freshly harvested seeds of Sirosa was mainly associated with the structures surrounding the caryopses (7.7 v. 79.5% mean germination), but for Taranna and Bunderra it was related to physiological dormancy of the caryopses.Germination levels that were not significantly different to the maximum occurred for temperature ranges of 35/30–15/10�C [Sirosa (commercial)], 35/25–15/10�C (Australian phalaris), and 35/30–15/05�C (Kangaroo Valley ryegrass). In contrast, maximum germination of wallaby grasses only occurred for Taranna in the temperature range 25/20–20/10�C, and for Bunderra at 25/15 and 20/15�C.Seedling emergence in the field was episodic, occurring on only 3 occasions from 1993 to 1996. No seedlings of Sirosa phalaris, Demeter tall fescue, or Kangaroo Valley ryegrass were successfully recruited, but Taranna and Bunderra successfully recruited new plants from natural seedfalls. Whereas seed production of the perennial grasses studied was relatively high (~10 000 seed/m2 in 1992), soil seedbank levels were much lower (generally <1000 seeds/m2). These data were used to indicate the likely successful establishment of sown perennial grasses or by regeneration from natural seedfall.



1991 ◽  
Vol 31 (4) ◽  
pp. 499 ◽  
Author(s):  
MH Campbell ◽  
BR Milne ◽  
JJ Dellow ◽  
HI Nicol

The effect of type of herbicide and time and rate of application on the reduction in ground cover of St John's wort (Hypericum perforatum L.) was determined at Orange, New South Wales. In January, April, July and November 1988, 8 herbicide treatments including the currently used glyphosate and picloram + 2,4-D were applied to vigorously growing H. perforaturn, and the reduction in percentage ground cover was recorded in December 1989. Ineffective herbicides (a.i./ha) were tebuthiuron, 0.8-6.4 kg; metsulfuron, 5-20 g; and paraquat + diquat, 0.4 + 0.5 kg. The addition of metsulfuron (2.5 g a.i./ha) to glyphosate (0.9 and 1.8 kg a.i./ha) did not increase the effectiveness of the latter. Effective herbicides (kg a.i./ha) were triclopyr + picloram, 0.6 + 0.2; picloram + 2,4-D, 0.2 + 0.8; glyphosate, 1.8; and triclopyr, 1.92. There was a strong trend for these herbicides to be more effective in January and November than in April and July. Based on price, effectiveness and selectivity, triclopyr + picloram would be preferred to the other herbicides for boom and spot spraying, and glyphosate would be the only herbicide suitable for aerial application prior to sowing improved pastures on non-arable land.



1987 ◽  
Vol 14 (2) ◽  
pp. 163 ◽  
Author(s):  
D. Lunney ◽  
B. Cullis ◽  
P. Eby

This study of the effects of logging on small mammals in Mumbulla State Forest on the south coast of New South Wales included the effects of a fire in November 1980 and a drought throughout the study period from June 1980 to June 1983. Rattus fuscipes was sensitive to change: logging had a significant impact on its numbers, response to ground cover, and recapture rate; fire had a more severe effect, and drought retarded the post-fire recovery of the population. The three species of dasyurid marsupials differed markedly in their response to ground cover, canopy cover, logging and fire. Antechinus stuartii was distributed evenly through all habitats and was not affected by logging, but fire had an immediate and adverse effect which was sustained by the intense drought. A. swainsonii markedly preferred the regenerating forest, and was not seen again after the fire, the failure of the population being attributed to its dependence on dense ground cover. Sminthopsis leucopus was found in low numbers, appeared to prefer forest with sparse ground cover, and showed no immediate response to logging or fire; its disappearance by the third year post-fire suggests that regenerating forest is inimical to the survival of this species. Mus musculus showed no response to logging. In the first year following the fire its numbers were still very low, but in the next year there was a short-lived plague which coincided with the only respite in the 3-year drought and, importantly, occurred in the intensely burnt parts of the forest. The options for managing this forest for the conservation of small mammals include minimising fire, retaining unlogged forest, extending the time over which alternate coupes are logged and minimising disturbance from heavy machinery.



1992 ◽  
Vol 32 (5) ◽  
pp. 627 ◽  
Author(s):  
GW Charles ◽  
GJ Blair ◽  
AC Andrews

The effects of sowing time (autumn and spring) and technique (conventional cultivation, inverted T direct drill, triple disc direct drill and aerial seeding), on the establishment of tall fescue into a weed infested pasture on the Northern Tablelands of New South Wales were examined. A pre-sowing herbicide treatment was included in the 2 direct drilling treatments, and heavy pre-sowing grazing was used in the autumn sowing. The design used 38 plots of 0.12 ha, analysed as 2 separate, complete block experiments, with some common treatments. Tall fescue establishment, 120 days after the autumn sowing, averaged 48 seedlingslm2 on the inverted T treatment (16% establishment). Establishment was improved by 63%, to 78 seedlings/m2, with herbicide and 46%, to 70 seedlings/m2, by heavy grazing. These effects were additive, giving 105 seedlings/m2 for the combined treatments. Only 52 seedlings/m2 established on the triple disc treatment with heavy grazing and herbicide, while establishment on the cultivated seedbed was not different from the inverted T (93 seedlings/m2). There was no establishment after the aerial seeding at either sowing. Fescue establishment showed the same trends in the spring sowing, with 140 seedlings/m2 on the inverted T treatment with pre-sowing herbicide, which was higher than the establishment of 107 seedlings/m2 on the cultivated seedbed. The fescue yield, 18 months after the autumn sowing, was highest in the autumn sown, inverted T treatment with pre-sowing herbicide and heavy grazing (123 kg/ha). In the spring sowing, fescue was recorded only on the cultivated treatment (84 kg/ha) and on the inverted T treatment with pre-sowing herbicide (39 kg/ha). These results show that tall fescue can be re-established into weed dominated pastures on the Northern Tablelands with direct drilling, in either autumn or spring, and that heavy, pre-sowing grazing and herbicide increase fescue establishment.



2004 ◽  
Vol 44 (3) ◽  
pp. 283 ◽  
Author(s):  
S. R. Murphy ◽  
G. M. Lodge ◽  
S. Harden

Surface runoff can represent a significant part of the hydrological balance of grazed pastures on the north-west slopes of New South Wales, and is influenced by a range of rainfall characteristic, soil property, and pasture conditions. Runoff plots were established on grazed pastures at 3 sites as part of the Sustainable Grazing Systems National Experiment (SGS NE). Pastures were either native (redgrass, wallaby grass and wire grass) or sown species (phalaris, subterranean clover and lucerne) and a range of grazing management treatments were imposed to manipulate pasture herbage mass, litter mass and ground cover. Rainfall and runoff events were recorded using automatic data loggers between January 1998 and September 2001. Stored soil water in the surface layer (0–22.5 cm) was monitored continuously using electrical resistance sensors and automatic loggers. Pasture herbage mass, litter mass and ground cover were estimated regularly to provide information useful in interpreting runoff generation processes.Total runoff ranged from 6.6 mm at Manilla (0.3% of rainfall) to 185 mm at Nundle (5.7% of rainfall) for different grazing treatments, with the largest runoff event being recorded at Nundle (46.7 mm). Combined site linear regression analyses showed that soil depth, rainfall depth and rainfall duration explained up to 30.3% of the variation in runoff depth. For individual sites, these same variables were also important, accounting for 13.3–33.6% of the variation in runoff depth. Continuous monitoring of stored soil water in relation to these runoff events indicated that the majority of these events were generated by saturation excess, with major events in winter contributing substantially to regional flooding. Long-term simulation modelling (1957–2001) using the SGS Pasture Model indicated that most runoff events were generated in summer, which concurred with the number of flood events recorded at Gunnedah, NSW, downstream of the SGS sites. However, floods also occurred frequently in winter, but the simulations generated few runoff events at that time of the year. These results have important implications for sustainability of grazed pastures and long-term simulation modelling of the hydrological balance of such systems, since runoff generation processes are likely to vary both spatially and temporally for different rainfall events.



Sign in / Sign up

Export Citation Format

Share Document