Use of a soil moisture model and risk analysis to predict the optimum time for the aerial sowing of pastures on the Northern Tablelands of New South Wales

1976 ◽  
Vol 16 (83) ◽  
pp. 871
Author(s):  
PM Dowling ◽  
RCG Smith
Keyword(s):  
Soil Moisture ◽  
New South ◽  
New South Wales ◽  
Practical Importance ◽  
Balance Model ◽  
Optimal Time ◽  
Plant Survival ◽  
South Wales ◽  
Close Relationship ◽  
June July

The objective of this study was to determine the time of year that maximized establishment and . minimized the risk of failure in aerial sowing of pasture seed on the Northern Tablelands of New South Wales. This was achieved by relating a set of monthly measurements of establishment spanning two years to mean soil moisture, predicted by a water balance model for the six-week period following sowing. From this relationship, establishment was simulated for 61 years using historical rainfall data to estimate probability density functions of establishment for each week of the year. From these functions it was concluded that maximum establishment with minimum risk can be expected from sowing in the June-July period. For perennial species plant survival over the first summer is of more practical importance than per cent establishment. Our data on plant survival, although not presented, indicated a close relationship existed between establishment and survival and supported the conclusion that the optimal time for oversowing is June-July.

Correction - Use of a soil moisture model and risk analysis to predict the optimum time for the aerial sowing of pastures on the Northern Tablelands of New South Wales

1976 ◽  
Vol 16 (83) ◽  
pp. 871
Author(s):  
PM Dowling ◽  
RCG Smith
Keyword(s):  
Soil Moisture ◽  
New South ◽  
New South Wales ◽  
Practical Importance ◽  
Balance Model ◽  
Optimal Time ◽  
Plant Survival ◽  
South Wales ◽  
Close Relationship ◽  
June July

The objective of this study was to determine the time of year that maximized establishment and . minimized the risk of failure in aerial sowing of pasture seed on the Northern Tablelands of New South Wales. This was achieved by relating a set of monthly measurements of establishment spanning two years to mean soil moisture, predicted by a water balance model for the six-week period following sowing. From this relationship, establishment was simulated for 61 years using historical rainfall data to estimate probability density functions of establishment for each week of the year. From these functions it was concluded that maximum establishment with minimum risk can be expected from sowing in the June-July period. For perennial species plant survival over the first summer is of more practical importance than per cent establishment. Our data on plant survival, although not presented, indicated a close relationship existed between establishment and survival and supported the conclusion that the optimal time for oversowing is June-July.

Seasonal trends and variability of soil moisture under temperate pasture on the Northern Tablelands of New South Wales

1975 ◽  
Vol 15 (73) ◽  
pp. 250 ◽  
Author(s):  
RCG Smith ◽  
GG Johns
Keyword(s):  
Soil Moisture ◽  
Field Experiments ◽  
New South ◽  
New South Wales ◽  
Late Summer ◽  
Summer Rainfall ◽  
Balance Model ◽  
Late Winter ◽  
Pan Evaporation ◽  
South Wales

A water balance model predicting changes in soil moisture under temperate pasture at Armidale, New South Wales was developed and tested against soil moisture measurements made from 1967 to 1969. The model accounted for 96 per cent of the variance in observed soil moisture. The model was then used to predict the expected pattern of soil moisture for this area using daily Armidale rainfall data from 1878 to 1973 and pan evaporation data from 1951 to 1970. Expected soil moisture levels rise to a maximum in late winter and then progressively decline to a minimum in mid summer. Levels may increase again slightly during late summer but remain low through autumn before beginning to rise again during winter. On the basis of this analysis it is suggested that the safest time to establish new plant species into temperate pasture is probably early winter when expected soil moisture begins to rise rapidly. Because of the autumn deficiency in soil moisture it was concluded that fodder oats grown in this period would often be inhibited by a lack of soil moisture unless preceded by a fallow to conserve late summer rainfall. The need for soil moisture data in interpreting and extrapolating from field experiments is stressed.

Merino ewe and lamb performance in the Central Tablelands of New South Wales following joining in March-April or June-July

1988 ◽  
Vol 28 (5) ◽  
pp. 561 ◽  
Author(s):  
HL Davies ◽  
E Devaud
Keyword(s):  
New South ◽  
New South Wales ◽  
Subterranean Clover ◽  
Late Pregnancy ◽  
Stocking Rate ◽  
South Wales ◽  
Group Number ◽  
Nutritional Advantage ◽  
June July ◽  
Group 1

A March-April joining of Merino ewes was compared with a June-July joining in central New South Wales at a low stocking rate on subterranean clover based pastures over 3 years. In all years, ewes joined in June were heavier (P < 0.05) than ewes joined in March (55 v. 52 kg). Liveweights at the start of lambing and liveweight change from joining to lambing were also high and favoured the later lambing group. The proportion of ewes lambing (97% March v. 93% June) and proportion of ewes twinning (29% March v. 20% June) were not significantly different between the 2 groups, but consistently favoured the March-April joining. Perinatal mortality was low (9.4% March v. 7.1% June) and not significantly different between the 2 groups, but was consistently lower in the June joined group. Number of lambs weaned per 100 ewes joined was also not significantly different, but was higher each year in the March joined group (1 13% March v. 105% June). The growth rate of the lambs (both singles [24% greater, 248 v. 200 g/day] and twins [37% greater, 2 13 v. 155 g/day]) was consistently in favour of March joined ewes. Mean greasy fleece weights of the ewes were not significantly different between the 2 groups, but were in favour of the late joined group (4.83 v. 4.50 kg). Time of joining significantly affected liveweights and greasy and clean fleece weights of the progeny at the shearing in the year following their birth in favour of March joining. These data suggest that, despite a nutritional advantage to the ewes in late pregnancy and milder weather at lambing with a June-July joining, a March- April joining is the preferred option on the Central Tablelands of New South Wales.

Predation of livestock by wild dogs in eastern New South Wales.

1989 ◽  
Vol 11 (2) ◽  
pp. 61 ◽  
Author(s):  
PJS Fleming ◽  
TJ Korn
Keyword(s):  
New South ◽  
New South Wales ◽  
Coastal Region ◽  
North East ◽  
The North ◽  
East Region ◽  
South Wales ◽  
Control Programmes ◽  
June July ◽  
Wild Dogs

A monthly survey involving officers from eastern New South Wales Pastures Protection Boards was conducted over four years from 1982 to 1985. Information was collected on the number and type of livestock attacked within each board district, sightings of wild dogs, the number of wild dogs kiied, the method by which they were kiied and the locations at which the observations occurred. A total of 25,644 livestock animals were reported killed or wounded from four regions; the North-East Coastal Region, the North-East Tablelands Region, the Central-East Region and South-East Region. Sheep were the most commonly attacked domestic animals followed by cattle and goats. Regional differences were apparent in the type of livestock killed and seasonal patterns of predation were evident. We recommend that annual control programmes be brought forward from June/July to late April in order to precede predation peaks.

The role of stolons and seedlings in the persistence and production of white clover (Trifolium repens L. cv. Huia) in temperate pastures on the Northern Tablelands, New South Wales

1989 ◽  
Vol 40 (3) ◽  
pp. 605 ◽  
Author(s):  
KA Archer ◽  
GG Robinson
Keyword(s):  
Soil Moisture ◽  
White Clover ◽  
Seedling Establishment ◽  
New South ◽  
New South Wales ◽  
Late Summer ◽  
South Wales ◽  
Cool Temperate ◽  
Plant Frequency ◽  
Temperate Pastures

This paper reports the findings of a five-year study on the growth patterns, production and means of persistence of white clover in a cool temperate environment with summer dominant rainfall, on the Northern Tablelands of New South Wales. White clover essentially persisted as a perennial, but large and rapid declines in plant frequency occurred during late summer if soil moisture levels became depleted. The critical combination of conditions at which plant frequency was adversely affected occurred when available soil moisture levels declined below 35 mm and mean weekly maximum temperatures exceeded 20�C; conditions which often occur in late summer in this environment. During one prolonged period of moisture stress in the second spring and summer period of the study, all plants died. Regeneration was due to germination of seeds and seedling establishment, but plants subsequently persisted as perennials. Relationships were developed to predict the probability of survival of white clover over the range of temperatures and soil moistures recorded in these experiments. Germination occurred to a variable extent each year, but was observed only during winter and spring. Seedling establishment was effective in only one year, which followed the death of white clover in summer, 1980-81. The sward was slow to recover after seedling regeneration owing to low winter temperatures and competition from established temperate perennial grasses in spring. Seedlings contributed little to dry matter production in spring. These results indicate that white clover is unlikely to be of value as an annual in temperate pastures. Strategies aimed at improving white clover in cool temperate environments, either by management or selection/breeding programs, should therefore focus upon improving the ability of white clover to persist as a perennial.

Differential habitat use by a local population of subadult common dunnarts, Sminthopsis murina, following wildfire in coastal wet heath, New South Wales, Australia

2005 ◽  
Vol 32 (7) ◽  
pp. 617 ◽  
Author(s):  
Vaughan Monamy ◽  
Barry J. Fox
Keyword(s):  
Soil Moisture ◽  
Habitat Use ◽  
New South ◽  
Habitat Preferences ◽  
Local Population ◽  
New South Wales ◽  
High Soil Moisture ◽  
South Wales ◽  
Unusual Occurrence ◽  
Habitat Fidelity

Little has been published about Sminthopsis murina, a small insectivorous marsupial encountered infrequently during trapping studies. Individuals favour vegetation associations found in recently burnt heathlands and forests; however, individuals rarely remain in such areas long enough for repeated capture. We report an unusual occurrence of habitat fidelity by a dense population of subadult S. murina in coastal wet heath, New South Wales, Australia. Individuals were captured repeatedly in the first 16 months following wildfire (30 subadults trapped 154 times: recapture rate = 80%). Densities peaked 10 months after fire at 3.75 individuals ha–1. More males than females were captured (23 males, 7 females). Habitat analyses revealed differential use of regenerating coastal wet heathland by S. murina. Significantly more captures were made in areas of high soil moisture in the first six months following fire. Captures then decreased in these areas but increased where soil moisture had been lower and where vegetation had been growing more slowly. Beyond the 1995/96 breeding season, regenerating vegetation became increasingly dense and less patchy and captures of S. murina ultimately declined to zero. This paper records a rare opportunity to examine habitat preferences of a single cohort of subadult S. murina. Habitat use may have been determined by the presence of a narrow range of vegetation structure.

Diel and tidal abundance of fish larvae in a barrier-estuary channel in New South Wales

2001 ◽  
Vol 52 (7) ◽  
pp. 995 ◽  
Author(s):  
T. Trnski
Keyword(s):  
Larval Fish ◽  
Fish Larvae ◽  
New South ◽  
New South Wales ◽  
Common Species ◽  
South Wales ◽  
Marine Source ◽  
Nursery Habitats ◽  
Current Flows ◽  
June July

In four 24-h series of ichthyoplankton sampling during winter (June–July) 1996 in Swansea Channel (which connects Lake Macquarie with coastal waters of central New South Wales, Australia) 3367 fish larvae representing at least 77 species were collected. The larval fish community clustered by sampling date and by diel phase. Diel phase had a stronger influence on abundance of more common taxa than did tide phase, and also most influence on community structure. For most taxa there was no difference in abundance between flood and ebb tides, regardless of the estuarine or marine source of the eggs and larvae. All but two of 16 common species were present in Swansea Channel throughout their entire larval stage. The sparids Acanthopagrus australis and Rhabdosargus sarbawere present in the channel only at settlement-competent sizes. These two species showed evidence of selective presence in the channel during a particular diel or tidal phase, with A. australis apparently preferring night-flood tides, which would aid migration to the estuarine nursery habitats in Lake Macquarie. The ability or inclination to escape the strong bi-directional flows in channels seems limited to only a few taxa that appear to respond to physical cues and tidal current flows.

Climatic conditions for seedling recruitment within perennial grass swards in south-eastern Australia

2012 ◽  
Vol 63 (4) ◽  
pp. 389 ◽  
Author(s):  
R. Thapa ◽  
D. R. Kemp ◽  
M. L. Mitchell
Keyword(s):  
Soil Moisture ◽  
New South ◽  
Perennial Grass ◽  
New South Wales ◽  
Climatic Conditions ◽  
South Eastern ◽  
South Wales ◽  
Eastern Australia ◽  
Moisture Conditions ◽  
South Eastern Australia

Recruitment of new perennial grass plants within existing grassland ecosystems is determined by seed availability, suitable microsites, nutrients and climatic conditions, water and temperatures. This paper reports on the development of criteria to predict recruitment events using modelled soil moisture conditions associated with recruitment of species in five field experiments at Orange (Phalaris aquatica), Trunkey Creek (Austrodanthonia spp.), and Wellington (Bothriochloa macra) in central New South Wales, Australia, and the frequency of those conditions during the past 30 years. Recruitment events were recorded when a rainfall event (median 68 mm across the three sites) kept the surface volumetric soil moisture (0–50 mm) above the permanent wilting point for at least 15 continuous days, allowing for, at most, two ‘dry days’ in between. A key finding from our study is that rainfall events creating favourable soil moisture conditions for seedling emergence typically occurred in the second half of February, sometimes extending to early March. Previously it was thought that recruitment would more likely occur through autumn, winter, and spring when rainfall in southern Australia is more reliable. The 30 years’ data (1975–2004) showed that the P. aquatica site had a median of 20 continuous moist days each year in February–March, whereas, there were 16 and 10 days for the Austrodanthonia and B. macra sites, respectively. The probabilities of exceeding seven or 15 continuous days of moist surface soil were 98% and 78% at the P. aquatica site, 91% and 49% at the Austrodanthonia site, and 73% and 30% at the B. macra site, and indicated that some recruitment is possible in most years. These analyses were extended to several sites across New South Wales, Victoria, and Tasmania to estimate the frequency with which recruitment could occur within natural swards. Across these sites, the probabilities of exceeding seven continuous days of soil moisture were >55% and of exceeding 15 continuous days were lower, which showed that suitable climatic conditions exist during late summer–early autumn across south-eastern Australia for a recruitment event to occur. Future research may show that the criteria developed in this paper could have wider regional application.

Forecasting wheat yields using a water budgeting model

1989 ◽  
Vol 40 (4) ◽  
pp. 715 ◽  
Author(s):  
I Cordery ◽  
AG Graham
Keyword(s):  
Water Balance ◽  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
New South ◽  
Meteorological Data ◽  
New South Wales ◽  
Balance Model ◽  
Soil Layers ◽  
South Wales

A model has been developed to forecast soil water variations and wheat crop growth in dry land situations. The forecast of the yield to be expected if sowing occurred today is obtained by running the calibrated model for all years for which meteorological data are available. The soil water content on today's date in each year is fixed at today's observed soil water value. From each year of observed meteorological data, an estimate is made of the yield. These yield data allow construction of a frequency distribution of yield which can be used to make a probabilistic forecast. The model involves two sub-models, a water balance model and acrop development model. The two sub-models interact to provide 5-day estimates of soil water content, actual evaporation and transpiration, runoff and increments to biomass and grain yield. The water balance model takes inputs of daily rainfall and estimated potential evapotranspiration. Available energy is partitioned between evaporation and transpiration depending on leaf area index. There are two soil layers plus a surface interception and depression store. Water removal from the soil layers is dependent on root development and the location of available water. Biomass production is driven by actual transpiration and transpiration efficiency and so biomass and grain development are dependent on the timing and amount of water and energy utilization by the crop. The model was first calibrated in northern New South Wales with 13 years of research station data. With minor recalibration, it provided good estimates of observed district wheat harvests for a continuous period of 75 years. Further recalibration with 30 years of shire data from Queensland, 29 years of single farm data in southern New South Wales and with 31 years of county data from northwestern USA., indicated the model is able to accurately reproduce observed yields and has the potential to provide reliable forecasts of yield, in a range of different climates.

Mixed model estimation of age and month of calving adjustment factors for milk and butterfat yields of New South Wales dairy cattle

1982 ◽  
Vol 33 (4) ◽  
pp. 731 ◽  
Author(s):  
RW Everett ◽  
JF Taylor ◽  
K Hammond
Keyword(s):  
Mixed Model ◽  
New South ◽  
New South Wales ◽  
South Wales ◽  
Younger Age ◽  
Adjustment Factors ◽  
June July ◽  
Jersey Cows ◽  
Genetic Trends ◽  
Friesian Cows

Month-age adjustment factors for milk and butterfat yields were estimated from 504063 lactations on 239 518 cows located in 6 145 herds in New South Wales by mixed model methods, which eliminate biases due to genetic trends, environmental trends and culling. June, July and August are the most favourable months for calving, and December and January are the least favourable, resulting in 8 to 22% less production. Friesian cows are less affected by calendar month of calving than the other breeds. Results indicate the existence of large differences between breeds in rate of maturity. Ayrshire and Jersey cows attain mature yields at a younger age than AIS, Guernsey, Friesian and AMZ cows.

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