Effect of surface-sown pod:seed mixtures on serradella establishment and persistence on rangelands in central New South Wales

2002 ◽  
Vol 42 (2) ◽  
pp. 143
Author(s):  
D. L. Michalk ◽  
M. H. Campbell

Aerial sowing is the only option for introducing improved pasture species into much of the non-arable, acid soil rangelands in central New South Wales. However, low germination of seeds in serradella pods is a major problem causing poor establishment. Sowing different combinations of pod and seed was investigated as a means of improving germination and subsequent persistence in an experiment between 1993 and 1997. Results indicated that a pod:seed mixture of 75:25 was the most suitable ratio for establishing yellow serradella (Ornithopus compressus) when broadcast into native grassland on hardsetting, non-arable, acidic hill country. Nodulation failure observed at this cold tablelands site confirmed the need for a more winter-active inoculant for yellow serradella.

1965 ◽  
Vol 16 (6) ◽  
pp. 981 ◽  
Author(s):  
J Lax ◽  
Turner H Newton

The influence of sex, strain, location, and age of ewe on survival rate to weaning of single-born Merino lambs has been examined in two sets of data: the strain trial, involving five strains run without selection at each of three locations (Cunnamulla, Qld.; Armidale, on the northern tablelands of New South Wales; Deniliquin, in the Riverina area of New South Wales), with six age groups of ewes; and the same five strains later included in selection groups at Armidale with seven age groups of ewes. The strain trial at Armidale ran mainly on native, and the selection groups mainly on improved pastures. Female lambs had a higher survival rate than either castrated or entire males, the differences in lambs weaned per lamb born being 0.03 and 0.04 respectively. No strain differences could be regarded as statistically significant, and neither could the strain x location interaction in the strain trial. Mean survival rates for the strains ranged from 0.673 to 0.786 on the Armidale native and from 0.802 to 0.850 on the Armidale improved pasture, from 0.746 to 0.859 at Cunnamulla, and from 0.838 to 0.894 at Deniliquin. The strains did not rank consistently in the same order. Location had a marked effect on survival rate, the means being 0.744 for the native and 0.824 for the improved pasture at Armidale, 0.810 at Cunnamulla, and 0.868 at Deniliquin. Age of ewe had a marked influence in the poorest environment (Armidale native pasture), survival rate rising with age and later falling sharply. The effect was less marked in the intermediate environments (Armidale improved pasture and Cunnamulla) and negligible at Deniliquin. The patterns at Cunnamulla and Deniliquin are confirmed by data from other experiments on these stations. Survival rate is one component of number of lambs weaned. The other component, number of lambs born, has a higher mean value at Deniliquin than Cunnamulla, but shows a strong association with age of ewe in both environments. Number of lambs born responds rapidly to selection, but no information is yet available concerning the likely response in survival rate. If improvement in environment can raise the survival rate, particularly in the youngest and oldest ewes, then selection for number of lambs born, combined with improved environment, should lead to a marked rise in the number of lambs weaned.


2004 ◽  
Vol 26 (2) ◽  
pp. 161 ◽  
Author(s):  
D. T. Vere ◽  
M. H. Campbell

Large areas of undeveloped pastures in non-arable hill country in eastern New South Wales could be improved by aerial methods. The potential economic benefits of pasture improving a portion of the hill country area were evaluated in terms of the economic welfare changes in the Australian wool industry. Hill country wool producers and international wool consumers would derive nearly all of the benefits from this process. Other Australian and international wool producers would lose economic welfare because of the reduced price from increased regional wool production. For conservative anticipated levels of pasture improvement adoption, the overall benefits to the Australian wool industry had 15-year mean present values of between $30.2 million and $122.1 million, depending on whether the introduced pasture was predominantly perennial grass or legume based. The value of this analysis is that it provides improved economic information for planning investment in new pasture technologies in the Australian livestock industries.


1962 ◽  
Vol 13 (6) ◽  
pp. 1059 ◽  
Author(s):  
JR Simpson

Soils under improved pasture on the Southern Tableland of New South Wales accumulated nitrate in substantial quantities during the summer and autumn. In this respect they behaved quite unlike the pasture soils which have been studied in most of the earlier literature, and they resembled cultivated fallow soils, which usually accumulate nitrate at the same time of the year. The nitrate was produced mainly in the top inch of soil; ammonium also accumulated under certain conditions. The precise sequence of climatic events, particularly the period of drying between consecutive wettings, was of primary importance in the nitrate accumulation. The nitrate produced during summer and early autumn disappeared from the topsoil after heavy rain in autumn and winter. The seasons could therefore be distinguished as a nitrogen-rich summer and autumn, a nitrogen-depleting winter, and a nitrogen-poor early spring, with an increasing supply of mineral nitrogen during late spring. No appreciable fluctuations in mineral nitrogen were found in soils resown directly from native pasture with less than 0.10% total nitrogen at 0-2 in.


1989 ◽  
Vol 37 (5) ◽  
pp. 375 ◽  
Author(s):  
JH Leigh ◽  
DH Wood ◽  
MD Holgate ◽  
A Slee ◽  
MG Stanger

The effects of rabbits and kangaroos, and rabbits alone, on the biomass and species composition of a native grassland dominated by Stipa nitida/nodosa, Danthonia caespitosa and Aristida contorta, and a grassland dominated by the exotic species Hordeum glaucum, Vulpia spp., Medicago laciniata and the native Erodium crinitum growing at Yathong Nature Reserve in central New South Wales was monitored between 1979 and 1985. Rabbits generally favoured the grassy component; kangaroos also favoured grasses but less so. Changes in non-grass species composition due to grazing was generally insignificant. Changes in species composition due to seasonal differences in rainfall was highly significant. No new species appeared on plots exclosed from grazing for 10 years, suggesting that the grazing by livestock, rabbits, and kangaroos in the past has determined the present species composition. The annual biomass consumption by rabbits averaged over 6 years was 100-200 kg ha-1, which is equivalent to reducing the carrying capacity by one sheep for every 2-4 ha rabbit-infested area. In the native grassland the spatial pattern of rabbit grazing, as indicated by faecal pellet distribution, biomass removal, and percentage of 'unpalatable' species in the pasture, shows greatest grazing pressure to be within 50 m of the warren, grazing intensity dropping off from there to 300 m the greatest distance studied. From the start of the study 'palatable' species, especially grasses, were at their lowest density within 50 m of the warren; this appeared to be a historical effect of grazing. No patterns were discernible in the pasture dominated by introduced species. Little change in species composition of these grasslands can be expected under a wide range of grazing pressure, except close to rabbit warrens.


1978 ◽  
Vol 18 (92) ◽  
pp. 411
Author(s):  
PM Dowling

The influence of resident vegetative cover on the establishment of surface sown seed was determined in a field experiment at Glen Innes, New South Wales. Seed was sown on 25 occasions over a period of 2 years spanning the period November 1969 to January 1972. Species sown were Phalaris aquatica, Festuca arundinacea, Medicago sativa and Trifolium subterraneum. The relationship between mean per cent establishment and vegetative cover was significant and was described by the quadratic equation y = 0.8064 � 9.8342x - 0.8829x2. Presence of vegetative cover significantly increased mean establishment on 22 occasions. Presence of Sorghum leiocladum plants as a component of the resident vegetation had a larger influence on establishment of surface sown species than Bothriochloa ambigua and Poa sieberana. It was concluded that the best means of obtaining maximum establishment of surface sown pasture species in native grassland areas on the Northern Tablelands of New South Wales was by sowing into vegetative cover (approximately 5000 kg ha-1) and sowing during the period May-July.


1976 ◽  
Vol 27 (1) ◽  
pp. 63 ◽  
Author(s):  
RCG Smith ◽  
MJ Stephens

A simple model for predicting pasture growth from climatic data was developed and tested against experimental data. The model was used to analyse climatic data from a 24-yr period (1950–1973) to elucidate the relative importance of soil moisture and temperature on the growth of improved pastures on the Northern Tablelands of New South Wales, and to predict the year-to-year variations in total pasture growth.Predicted yearly dry matter production varied between extremes of 5000 kg ha-1 yr-1 in 1965 and 14,000 kg ha-1 yr-1 in 1971. Soil moisture was the major factor limiting pasture growth from the beginning of October until the end of May, and temperature was the major limiting factor from the end of May to early October. During May and October there was a period when both factors had a similar probability of being the most limiting factor. Variations in soil moisture caused greater within-year variability in pasture growth than temperature except in April and September when variability caused by temperature equalled that caused by soil moisture. The significance of these effects is discussed.


1979 ◽  
Vol 19 (99) ◽  
pp. 476 ◽  
Author(s):  
MH Campbell ◽  
AR Gilmour ◽  
DT Vere

The effects of time and rate of application of tetrapion on burnt and unburnt serrated tussock, growing with and without improved species, were measured in four experiments carried out near Bathurst, New South Wales, between 1975 and 1978. Tetrapion proved effective in killing unburnt serrated tussock when applied in each season of the year. The most economical rates proved to be 1.00 kg a.i, ha-1 in spring and summer and 1.33 kg a.i. ha-1 in autumn and winter. Tetrapion was also effective in killing serrated tussock that had been burnt six and nine months before spraying. Although tetrapion had harsh phytotoxic effects on Phalaris aquatica and Trioflium repens growing in association with serrated tussock, these improved species recovered. Thus it proved possible to selectively remove serrated tussock from P. aquatica and T. repens by using tetrapion. Based on 1979 costs, tetrapion appears an economic alternative to other herbicides currently used to kill serrated tussock.


1975 ◽  
Vol 15 (73) ◽  
pp. 149
Author(s):  
DW Hennessy ◽  
GG Robinson

To overcome a winter-sp nes, New South Wales forage oats were sown into forty-five per cent of improved pasture (mainly Phalaris tuberosa and Trifolium repens) areas and the liveweight gains of weaner cattle grazing these areas from March to October were compared with those grazing pasture only. Three methods for managing the grazing of the forage oats were compared in 1971, and in 1972 the effect of an oat grain supplement on liveweight gain of cattle grazing either pasture only or pasture and forage oats was measured. Weaners did not reach 270 kg by October, the objective mean liveweight, in any of the treatments or years. Neither did forage oats significantly increase beef production from pasture, but when properly managed did reduce the need for hay supplements to maintain weaner liveweight during winter. Although the stocking rate of 2.82 weaners ha-1 from March to October was apparently too high in 1971 to allow adequate liveweight gains, the forage oats and pasture were best utilized by allowing weaners to graze freely between paddocks. Oat grain supplements in 1972 did improve weaners' liveweights (at intakes of 1 .O-2.0 per cent liveweight) but reduced the relative economic return from either the pasture or pasture and forage oat areas. We concluded from the study that forage oats sown into improved pasture areas did not increase feed availability in the latter part of the feed-gap nor reliably increase beef production from pasture at the stocking rate studied.


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