Agricultural drought analyses for temperate Australia using a biophysical pasture model. 2. Relationship between rainfall and the start and end of predicted droughts

2008 ◽  
Vol 59 (11) ◽  
pp. 1061 ◽  
Author(s):  
G. M. Lodge ◽  
I. R. Johnson
Keyword(s):  
New South ◽  
Summer Rainfall ◽  
Growing Season ◽  
Agricultural Drought ◽  
Wagga Wagga ◽  
Climate Data ◽  
Winter Rainfall ◽  
Rainfall Occurrence ◽  
South Wales ◽  
The Relationship

This paper reports relationships between predicted soil water content (SWC) on the first day of the month (SWCFOM, mm of water) and previous monthly rainfall for 100 years of daily climate data (1905–2005) at four sites (Albany, Western Australia; Hamilton, Victoria; and Wagga Wagga and Barraba, New South Wales). Overall, predicted SWCFOM was correlated (P < 0.05) with rainfall in the previous one, two, or three months. However, the proportion of variation in SWCFOM that could be attributed to its regression on previous rainfall was variable and the relationship tended to improve when individual months were examined. At the three winter-rainfall sites (Albany, Hamilton, and Wagga Wagga), there was a reasonably good relationship between the start of a predicted drought and the end of the growing season and also between the end of a predicted drought and the occurrence of break-of-season. However, for the summer-rainfall dominant site at Barraba, rainfall occurrence was less seasonally defined and there was no clear relationship. While analysis of historical rainfall data for the months in which predicted agricultural droughts started or ended provided some useful insights, it was concluded that it would probably be more instructive to model SWC outcomes for a range of future rainfall scenarios and then examine their likelihood of occurrence using rainfall percentiles.

Agricultural drought analyses for temperate Australia using a biophysical pasture model. 1. Identifying and characterising drought periods

2008 ◽  
Vol 59 (11) ◽  
pp. 1049 ◽  
Author(s):  
G. M. Lodge ◽  
I. R. Johnson
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
New South ◽  
New South Wales ◽  
Agricultural Drought ◽  
Wagga Wagga ◽  
Winter Rainfall ◽  
Seasonal Drought ◽  
South Wales

The SGS Pasture Model was used to estimate daily total soil water content (mm) for the period 1998–2001 (using experimental data) and from July 1905 to June 2005 (using a 100-year daily climate file). For both model simulations, the correlation coefficient for actual and predicted data was >0.86. Four sites were examined, three in the winter-rainfall zone (Albany, Western Australia; Hamilton, Victoria; and Wagga Wagga, New South Wales) and one in the predominantly summer-rainfall zone (Barraba, New South Wales) of temperate Australia. Trends were detected in long-term rainfall data for lower mean annual rainfall at the Albany site since the mid 1950s and at the Hamilton site since the mid 1970s. Analyses of days in which herbage accumulation was likely to be limited only by water allowed a minimum soil water content to be defined; below this value, soil water was in deficit. A drought period was defined as occurring after >50 consecutive days of predicted soil water deficit. For the four sites, six categories of drought duration were described, ranging from >50–120 days (seasonal drought) to >364 days (exceptional drought). Numbers of predicted droughts were 90, 90, 65, and 60, respectively, at Albany, Hamilton, Wagga Wagga, and Barraba sites. At the three winter-rainfall sites, most predicted droughts occurred in a regular pattern and were an extension of a seasonal drought, but at the Barraba site they were of a longer duration and irregular in occurrence.

The butterfly fauna of the Griffith district, a fragmented semi-arid landscape in inland southern New South Wales

2006 ◽  
Vol 12 (2) ◽  
pp. 140 ◽  
Author(s):  
Michael F. Braby ◽  
Ted D. Edwards
Keyword(s):  
Species Richness ◽  
Arid Zone ◽  
New South ◽  
New South Wales ◽  
Summer Rainfall ◽  
Wagga Wagga ◽  
Fragmented Landscape ◽  
South Wales ◽  
Butterfly Fauna ◽  
Semi Arid

Thirty-three species of butterflies are recorded from the Griffith district in the semi-arid zone of inland southern New South Wales. The butterfly community comprises the following structure: 19 species (58%) are resident; 7 (21 %) are regular immigrants; 2 (6%) are irregular immigrants; 5 (15%) are vagrants. Except for a few migratory species, most occur in relatively low abundance. Lack of similar studies elsewhere in western New South Wales precludes generalizations regarding the species richness, composition and structure of semi-arid butterfly communities. Comparison of the butterfly fauna with that from five other inland regions on the slopes and foothills of the Great Diving Range, revealed that the Griffith district is most similar in species richness and composition to that of Deniliquin and to a lesser extent Wagga Wagga and Cowra in the south, than with two regions in the higher summer rainfall area of the north of the State (Coonabarabran-Mendooran, Narrabri-Bellata). Overall, the butterfly fauna of inland New South Wales (total of 73 species, of which 49 occur in the southern regions) is depauperate compared with that recorded from the coastal/subcoastal areas east of the Great Dividing Range. Attention is drawn to the conservation significance of several vegetation types and habitat remnants in the Griffith district. Much of the native vegetation in the district has been extensively modified since European settlement due to excessive clearing for agriculture, resulting in a highly fragmented landscape for the conservation of native flora and fauna. With the exception of the lycaenid Candalides hyacinthinus Simplex, which is considered threatened locally, there is a general absence of narrow range endemic butterflies associated with mallee-heathland or mallee-woodland, possibly as a result of widespread land clearing practices of mallee vegetation in the past.

The ecology of Sminthurus viridis (Collembola) III. The influence ofclimate andl land use on its distribution and that of an important predator, Bdellodea lapidaria (Acari : Bdellidae)

1971 ◽  
Vol 19 (2) ◽  
pp. 177 ◽  
Author(s):  
MMH Wallace ◽  
JA Mahon
Keyword(s):  
Land Use ◽  
Low Temperatures ◽  
New South ◽  
New South Wales ◽  
Summer Rainfall ◽  
Growing Season ◽  
Predatory Mite ◽  
South Wales ◽  
Important Predator ◽  
Distribution Limits

The lucerne flea, S. viridis, is restricted to the southern parts of Australia and, apart from a few isolated occurrences in eastern New South Wales, occurs only in areas with an essentially Mediterranean-type climate. The northern inland limit to its distribution agrees closely with the 250-mm isohyet for the growing season of May-October inclusive. The eastern limit to distribution in New South Wales and Victoria agrees with a December-March isohyet of 225 mm. Areas east of this line receive predominantly summer rainfall, and the pastures contain a high proportion of perennial plants which probably do not provide the nutritional stimulus for the development of aestivating diapause eggs in S. viridis essential for oversummering. The predatory mite B. lapidaria requires slightly moister conditions than S. viridis and the limit of its inland distribution agrees reasonably well with the 260-mm isohyet for the May-October period. Low temperatures (mean maximum < 17.5'C) also seem necessary during this period. The eastern distribution limits in Victoria are similar to those of S. viridis.

Vegetative Attributes, Taxonomy, and Character Syndromes in Grasses Around a Sheep Camp on the Northern Tablelands of New South Wales

1995 ◽  
Vol 43 (3) ◽  
pp. 317 ◽  
Author(s):  
RW Rogers
Keyword(s):  
Life Form ◽  
New South ◽  
New South Wales ◽  
Growing Season ◽  
Distribution Patterns ◽  
Contingency Analysis ◽  
Significant Relationships ◽  
South Wales ◽  
Species Groups ◽  
The Relationship

Thirty common grasses from unfertilised sheep pastures of the Northern Tablelands of New South Wales were grouped according to their distribution about a sheep camp. The frequency and relative frequency of 16 of these grasses related to their distribution. It is argued that the distribution patterns detected can be attributed to stocking by sheep. The relationship between distribution, origin of the species, life cycle, life form and growing season were examined, and all were found to show statistically significant relationships. When the species were clustered using vegetative attributes which were significantly related to distribution, groups were formed which related more to taxonomy at tribal level than to distribution. Contingency analysis, relating the presence of the same attributes to species groups based on distribution pattern, showed that only photosynthetic mechanism and origin were related to that pattern, whereas all attributes, except origin, were related to tribe. Although individual characters are related to distribution and hence presumably to stocking, there is no single syndrome of characters related to distribution.

Effects of sowing time on growth and grain yield of lupin and field pea in south-eastern New South Wales

1994 ◽  
Vol 34 (8) ◽  
pp. 1137 ◽  
Author(s):  
DP Heenan
Keyword(s):  
Dry Matter ◽  
New South ◽  
New South Wales ◽  
Black Spot ◽  
Summer Rainfall ◽  
Field Pea ◽  
Wagga Wagga ◽  
Sowing Time ◽  
South Wales ◽  
Matter Production

Cultivars of lupin and field pea were grown at different times over 4 years on a red earth at Wagga Wagga, New South Wales, to assess the influence of sowing time on growth and production from each crop. The cultivars of field pea (Pisum sativum) included Dinkum, Derrimut, Dunn, and Maitland; lupins used were Lupinus angustifolius cvv. Danja, Gungurru, and Geebung, and either the L. angustifolius line 75A/330 (1989-90) or L. albus cv. Ultra (1991-92). When autumn rain was sufficient to allow sowing, highest yield and dry matter production of lupin were gained by sowing from late April to 19 May. Yields declined with later sowing, though high spring-summer rainfall in 1992 reversed the decline. There was little difference between Danja, Gungurru, and Geebung, but these were usually higher yielding than the semi-dwarf 75Al330 when sown early. However, Ultra produced higher yields than the L. angustifolius cultivars in 1991 and 1992, particularly under high rainfall conditions. Early-sown crops (late April-mid May) of field peas were often severely infected with black spot blight and, in 1 year, with sclerotinia. In 1992 these diseases devastated all cultivars when sown on 1 May. Sowing later markedly reduced disease infection but also reduced grain yields and dry matter when sown after late June. The semi-leafless, semi-dwarf cultivar Dinkum was usually the lowest yielding and displayed the highest incidence of black spot blight.

Soil-extractable sulfur and pasture response to applied sulfur

1998 ◽  
Vol 38 (6) ◽  
pp. 567 ◽  
Author(s):  
G. C. Anderson ◽  
R. D. B. Lefroy ◽  
G. J. Blair
Keyword(s):  
Dry Matter ◽  
New South ◽  
Growth Period ◽  
Acid Digestion ◽  
Extraction Techniques ◽  
Organic S ◽  
South Wales ◽  
Trifolium Repens L ◽  
Soil Sulfur ◽  
The Relationship

Summary. A glasshouse experiment was conducted to study the correlation between various soil sulfur (S) extractants and pasture response to applied S grown under controlled environmental conditions (glasshouse) as influenced by variations in levels of extractable S. Intact paired soil cores were collected at 2-month intervals from an S x P factorial experiment at 4 field sites on the Northern Tablelands of New South Wales on 11 occasions. Soil samples were collected from each core and the cores placed in the glasshouse. Sulfur was applied to one core of each pair and basal nutrients applied to all cores which were then oversown with white clover (Trifolium repens L. cv. Haifa). The extractable S in the soil was analysed using the following techniques: 0.1 mol Ca(H2PO4)2/L (MCPt); 0.1 mol Ca(H2PO4)2/L, treated with activated charcoal (MCPi); water (H2O); 0.25 mol KCl/L, heated at 40°C for 3 h (KCl-40); 0.25 mol KCl/L, heated at 100°C for 4 h (KCl-100); 0.5 mol NaHCO3/L (NaHCO3); and an acid digestion of the soil (total). Dry matter yield and S content of the pasture shoots were measured for each 2-month growth period. The relationship between the various soil S extraction techniques and the response of pasture to applied S varied over time and was influenced by the level of inorganic S present in the soil and the amount of organic S extracted. When the level of MCPi-extractable S ranged between 2 and 22 µg S/g soil due to the application of fertiliser (summer 1987–88 and autumn 1988), or after a period of high mineralisation rates (spring 1988), the MCPi, MCPt, H2O and KCl-40 techniques had the highest correlation with the increase in S content of the pasture when S was applied. The higher correlation for the MCPt, H2O and KCl-40 techniques than the MCPi technique indicates that plants obtained some S from the organic S pool. In contrast, when the levels of MCPi-extractable S ranged between 2 and 10 µg S/g soil and the rate of mineralisation increased in response to an increase in soil temperature (June 1988 and June 1989) or moisture (September 1989) upon transfer of samples from the field to the glasshouse, the MCPt, H2O and KCl-40 techniques underestimated the available S pool and had lower r2 values than either the KCl-100 or NaHCO3 techniques.

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