bluuebunny/crossref_metadata_2025 huggingface dataset:
Management of soil acidity in long-term pastures of south-eastern Australia: a review
Authors: Scott B. J. , Ridley A. M. , Conyers M. K.
Published: September 2002

Acidification of non arable soils under long-term pasture presents a major
agricultural problem in the high rainfall areas (≥600 mm/year) of
central and southern New South Wales and north-eastern Victoria. Some of these
soils were already strongly acid to depth before agriculture. Evidence
suggests that persistence of pasture species tolerant of acidic soils is being
affected adversely on a number of severely acidic soils. Acidification
processes are well understood but the capacity for grazing enterprises to pay
for amendment by lime application is a major constraint in long-term pasture
areas. In addition, soil acidification is likely to have substantial off-site
effects on water quantity and quality and as a result, on dryland salinity.
However, there is a paucity of scientific evidence to link soil acidity and
dryland salinity in this way.
Production from a grazing enterprise can be maintained by selecting plants for
tolerance of acidity, surface application of lime or a combination of both.
Responses by subterranean clover, lucerne and perennial grass (mainly phalaris
and cocksfoot)-based pastures to incorporated lime are reported, but there is
limited evidence of responses to surface applied lime. The movement of the
lime effect into the soil from surface application is suggested as a major
factor in controlling lime responses by plants. There is a need for more
confidence in the benefits of topdressed lime in non arable soils before
producers are likely to adopt the practice. High subsurface acidity in many
soils is a major limitation to the range of species that can be grown. In the
longer term, the use of lime may remove constraints on the use of productive
species such as lucerne.
Other options for acidic soils where slope is less than 10% are for the
grazing system to be modified or intensified, or for crop or horticultural
production. Costs of lime could be justified through more profitable
enterprises than traditional grazing operations. Low input systems based on
native grasses are intrinsically appealing, however, this is only possible
where a premium is paid for such produce (such as super fine wool).
Forestry is an option where suitable land and infrastructure are present and
should slow soil acidification and minimise off-site impacts. Land retirement
may be a useful option for some parts of the landscape that contribute
disproportionately to environmental problems. Private and government funded
land retirement may have a role to play.
Levels of pasture substitution when concentrates are fed to grazing dairy cows in northern Victoria
Authors: Stockdale C. R.
Published: September 2002

This paper aims to provide information for farmers and their advisers to
predict levels of substitution that might be occurring under various feeding
conditions in northern Victoria. The approach taken involved compiling data
from research conducted in northern Victoria and subjecting these to multiple
regression analysis to define the key variables affecting substitution and
marginal responses in milk production when concentrates are fed.
A significant relationship was obtained between level of substitution (kg DM
reduction in pasture intake/kg DM of concentrates eaten) and
unsupplemented pasture intake (PI, kg DM/100 kg liveweight) when
concentrates are fed. The regression relationship also included species
composition of the sward being grazed (species: +1 grass, 0 clover),
season of the year (season: +1 spring, 0 summer, –1 autumn) and
concentrate intake (kg DM/cow.day). The equation is:
Substitution = –0.34 + 0.16 ( 0.035) PI + 0.16 ( 0.053)
species + 0.11 ( 0.024) season+ 0.03 ( 0.014) concentrate intake
[100R 2 = 50.9
(P<0.01); r.s.d. = 0.14; CV =
37.7%].
Substitution increased by 0.16 kg DM/kg DM for each increment of pasture
intake. At any pasture intake, grass-dominant pastures, regardless of whether
the grass was perennial ryegrass (Lolium perenne) or
paspalum (Paspalum dilatatum), resulted in 0.16 kg
DM/kg DM more substitution than white clover
(Trifolium repens)-dominant pastures. In addition,
substitution was 0.11 kg DM/kg DM higher in spring than in summer, and
0.11 kg DM/kg DM higher in summer than in autumn. Finally, substitution
increased by 0.03 kg DM/kg DM for each additional kg DM of concentrates
offered.
Marginal returns in milk production (MR, kg extra milk/kg DM of
concentrates eaten) were negatively related to substitution according to the
following regression equation:
MR = 2.62 – 0.80 ( 0.216) substitution – 0.28 ( 0.084)
season – 0.34 ( 0.086) body
condition[100R2 = 62.9
(P<0.01); r.s.d. = 0.23; CV =
29.6%].
Marginal responses were 0.28 kg/kg DM lower in spring than in summer and
autumn (season: +1 spring, 0 summer–autumn), and each unit
improvement in body condition reduced expected marginal returns by 0.34
kg/kg DM.
These relationships, together with those developed to aid estimates of
unsupplemented pasture intake, can be used as background information in
decision support systems to help farmers and their advisers make more informed
decisions about feeding strategies when supplements are fed than has hitherto
been possible.duct
Improving nitrogen fixation of crop legumes through breeding and agronomic management: analysis with simulation modelling
Authors: Herridge D. F. , Turpin J. E. , Robertson M. J.
Published: September 2002

The nitrogen fixed by legumes is a valuable resource in agriculture, with crop
legumes alone contributing as much as 20% of the nitrogen requirements
of the world’s grain and oilseed crops. Increasing legume nitrogen
fixation through genetic improvement and more efficient management would have
large economic benefits. Breeding for improved nitrogen fixation has, to a
large extent, not been successful. Suggested reasons include the difficulty in
combining single traits like nitrogen fixation with other traits, such as
disease resistance, seed quality and yield, a lack of focus of programs and a
lack of screening methodologies. Agronomic management of legume nitrogen
fixation offers other opportunities. The challenge is to package those
opportunities and provide legume growers with tools for understanding the
factors determining nitrogen fixation, while at the same time providing them
with site-specific management options.
The potential of simulation modelling for assessing genetic and management
options for enhancing nitrogen fixation of soybean grown at Warwick in
south-eastern Queensland was investigated in a series of 30-year simulations
using the APSIM modelling framework. The APSIM–soybean module was first
adjusted to reflect observed responses of nitrogen fixation to soil nitrate.
The subsequent simulations indicated that (genetically based) symbiotic
nitrate tolerance would have only marginal benefits on residual soil nitrate
(7 kg N/ha at sowing soil nitrate of 100 kg N/ha). Management of the
crop for highest grain yield through optimising sowing dates, plant density
and fallow length provided the best opportunities for increasing nitrogen
fixation. The use of APSIM as a tool for managing legume nitrogen fixation
appears to have merit.
Managing tillage, sowing rate and nitrogen top-dressing level to sustain rice yield in a low-input, direct-sown, rice - vetch cropping system
Authors: Cho Y. S. , Choe Z. R. , Ockerby S. E.
Published: September 2002

Direct sowing of rice into drained soil is a relatively new farming practice,
replacing transplanting, being developed for use in External Low Input
Sustainable Agriculture in Korea. Field experiments were conducted to
investigate the importance of tillage, sowing rate, and top-dressing of
fertiliser nitrogen (N) to rice growth and grain yield in a direct-sown,
rice–vetch cropping system.
From 1993 to 1997, Chinese milk vetch
(Astragalus sinicus L. Vetch) was grown during the
winter season (October–May) at Uiryong, Korea. Until 1995 transplanted
rice (Oryza sativa L.) was grown during the summer
season, but in 1996 and 1997 the direct-sowing method was used. In 1996, the
treatments applied to rice were either tillage or no-tillage of the paddy
before the rice crop was sown, combined with 2 rates (0 or 2
g/m2) of fertiliser N top-dressed onto the paddy
just after the panicle initiation stage. In 1997, the treatments were either
tillage or no-tillage of the paddy before the rice crop, combined with 2 rice
sowing rates (400 or 800 seeds/m2), and 3 rates (0,
2 or 4 g/m2) of fertiliser N top-dressed just after
the panicle initiation stage.
Rice yielded 243–435 g/m2 in 1996 and
493–678 g/m2 in 1997, the lower yield in 1996
was attributed to fewer established seedlings and productive panicles. There
was no effect of tillage treatment. Across years, yield was correlated with
shoot N content, and grain N-use efficiency exceeded 50 g grain/g shoot N
content. Rice residues contained about 5 g N/m2 and
vetch residues released 6–8 g N/m2 during the
4 weeks after submergence, therefore the release of N from residues was
potentially sufficient to supply the rice crop demand. In both years, however,
the yield of unfertilised rice was N limited, so increasing the shoot N
content appeared to be the most important issue to be resolved in sustaining
yield in External Low Input Sustainable Agriculture. A low rate of top-dressed
fertiliser N (2–4 g N/m2) increased yield by
increasing the number of panicles and spikelets, and to a lesser extent,
1000-grain weight. Growing rice using no-tillage practices did not limit the
yield of rice, except in 1996 when no fertiliser N was applied and the N
uptake by rice was low. A high sowing rate combined with top-dressed
fertiliser N in 1997 reduced yield through crop lodging and an increase in the
number of unproductive tillers. This problem may be overcome by the use of a
variety less susceptible to lodging.
Effect of Pleiochaeta setosa on field responses of Lupinus angustifolius and L. luteus to applications of phosphorus
Authors: Bolland M. D. A. , Sweetingham M. W. , Jarvis R. J.
Published: September 2002

The effect of the fungus Pleiochaeta setosa on grain
yield responses of lupins to applications of phosphorus (P) fertiliser
(0–40 kg P/ha as triple superphosphate banded 80 mm below seed
while sowing at 40 mm) was measured for 4 lupin cultivars that differed in
reaction to the pathogen: Lupinus angustifolius cv.
Merrit (susceptible), cv. Tallerack (moderately resistant), cv. Myallie
(resistant) and L. luteus cv. Teo (very resistant).
Variable levels of P. setosa inoculum (as resting spores
in the soil) were generated by different rotations. Disease levels of lupin
foliage were manipulated by either burning or retention of the previous wheat
(Triticum aestivum) stubble.
The severity of brown spot (caused by P. setosa
infecting the foliage) was influenced by the previous rotation, by the stubble
treatment, and by the susceptibility of each lupin cultivar to the disease.
Pleiochaeta setosa was least in and had little or no
effect on yield of the very resitant Teo, but
P. setosawas greatest and decreased yields most in the
susceptible Merrit. Where grain yields were affected by
P. setosa, there were increases in grain yield with
increasing amounts of P applied. For Merrit, Tallerack and Myallie, grain
yield responses to P addition tended to increase with increasing disease.
Grain yield increases to P application were greatest for Merrit with the
highest P. setosa level, and were least for
L. luteus cv. Teo with the lowest
P. setosa level.
Management of a sodic soil for wine grape production
Authors: Wheaton A. D. , McKenzie B. M. , Tisdall J. M.
Published: September 2002

Sodic soils, which are widespread in Australian wine growing regions, restrict
plant performance through poor soil and water and soil and air relations. In
the northern Goulburn Valley of Victoria, an experiment was conducted from
1995 to 1998 in a vineyard block established with Chardonnay on Ramsey
rootstock in 1972. The experiment was to improve root growth and vine
performance by minimising hardsetting and crusting of the surface soil and
decrease its susceptibility to waterlogging by improving water flow into the
sodic subsoil. The factorial combinations of gypsum or no–gypsum and
wheat straw or ryegrass were applied to the vine line in a randomised block
design.
The improvement in grapevine performance was attributed to improved soil
conditions for root growth and water movement. Soil electrical conductivity
(EC) to 500 mm depth was increased by at least 36%, about 15 months after
application of 12 t/ha gypsum, and the effect was maintained at least 40
months after application. The increase in EC was associated with a decrease in
spontaneous dispersion at these depths. The application of wheat straw to
gypsum–treated soil decreased EC by 52% at 200–300 mm depth but
concentrations of water–soluble plus exchangeable
Ca2+, Mg2+ and total cations were
unaffected. The contributions of water–soluble plus exchangeable
Ca2+, and water–soluble plus exchangeable
Mg2+ by wheat straw to soil (not gypsum–treated)
at 200–300 mm depth were apparent, as concentrations were similar to
those in gypsum–treated soils without wheat straw.
Forty months after application of gypsum, the exchangeable sodium percentage
(ESP) was decreased by at least 26% at a depth of at least 500 mm depth.
Spontaneous dispersion was greater in soil with wheat straw applied at
0–100 mm depth than in soil with ryegrass grown, and reflects the
influence of organic anions from decomposing wheat straw and the ability of
ryegrass to stabilise soil. The stabilising ability of gypsum and ryegrass is
reinforced by the greater depth of soil maintained at less than 1 MPa
penetration resistance in these treatments, as well as an increase in
hydraulic conductivity.
Improved method for assessing rice soil suitability to restrict recharge
Authors: Beecher H. G. , Hume I. H. , Dunn B. W.
Published: September 2002

Groundwater recharge below ponded rice fields is a significant contributor to
rising groundwater levels and the threat of soil and water salinisation.
Reduced groundwater recharge is essential for sustainable rice based,
irrigated farming systems in southern Australia. Currently a soil is deemed as
suitable for rice production if 1 soil profile per 4 ha contains 2 m or more
of continuous medium or heavy clay textured material. However, this study
showed clay content to be a poor predictor of groundwater recharge.
Electromagnetic induction surveys of rice fields can show variation in soil
physico–chemical properties across rice fields. This allows the
delineation of distinctly different areas of a field based on EM readings and
allows accurate targeting of soil sampling and measurements. This study used
soil chemical and physical properties and groundwater recharge data to assess
the adequacy of the current rice soil suitability classification method. A
3-stage classification scheme of rice land suitability is proposed including
EM31 soil mapping and measurement of soil sodicity as key components. The
proposed scheme is as follows: (i) include the soil as suitable if the EM31v
measurement is equal to or greater than 150 mS/m; (ii) if EM31v <150,
include the soil if the ESP of the top 60 cm of the soil is greater than 6, or
the ESP of the depth interval between 60 and 150 cm is greater than 12; (iii)
all other soils are excluded from ricegrowing. The proposed scheme's ability
to correctly identify low permeability soil in rice fields as suitable for
rice growing was confirmed by the recharge values measured in these fields.
Ability of retained stubble to carry-over leaf diseases of wheat in rotation crops
Authors: Bhathal J. S. , Loughman R.
Published: September 2002

Increasingly, wheat rotations on sand-plain soils in Western Australia are
being managed with stubble retention practices for reasons of moisture and
soil conservation. A major concern in stubble retention practices is an
associated increase in risk from septoria nodorum blotch
(Phaeosphaeria nodorum) and yellow spot
(Pyrenophora tritici-repentis). These pathogens
frequently occur together in the region and survive in crop surface residues.
The amount of disease carry-over on stubble is an important determinant of the
severity of leaf diseases during the entire crop season. To provide a
rationale for wheat leaf disease management in stubble retention rotation
systems the extent to which retained wheat stubble induces disease in rotated
crops was investigated. The frequency with which wheat stubble, which had been
retained through a 1-year rotation, induced significant disease in seedling
wheat was low (14%) over the 4-year period of study. While disease
carry-over from wheat stubble retention in rotations is possible, it appears
to be uncommon. The small proportion (1–8%) of retained wheat
stubble that remained after germination of the return wheat crop in typical
Western Australian farming systems further indicates that in general retained
wheat stubble is not a significant source of disease carry-over in rotation
wheat crops in this environment.
Residual value of zinc fertiliser for production of wheat
Authors: Brennan R. F.
Published: September 2002

Zinc deficiency is common on the sandy acidic soils in south Western Australia
for grain production of wheat grown with diammonium phosphate containing low
levels of zinc contamination. The effectiveness of zinc fertiliser (zinc oxide
or zinc contamination of single superphosphate that were widely used for crops
in south Western Australia) was measured in 1996 for grain production of
wheat, for zinc applied once only to plots, either in 1996 (current zinc) or
in a previous year (previous zinc) (1983, 1984, 1986, 1990, 1992). Relative to
current zinc applied as zinc oxide with diammonium phosphate, the
effectiveness of previous zinc for dry matter, zinc uptake (zinc concentration
× yield) and grain production of wheat decreased relative to the
effectiveness of current zinc, the decrease being larger with increasing time
since application. Thirteen years after application, the decrease in the
effectiveness was about half for dry matter and grain production where wheat
was grown with diammonium phosphate. Both currently and previously applied
zinc fertiliser increased wheat dry matter, zinc content of the dry matter and
grain yields. Zinc applied as a zinc contaminant in single superphosphate in
1983 produced wheat grain yields on the maximum grain yield plateau (about 2.4
t/ha) achieved for the 5 amounts of zinc oxide applied in the current year
(1996). The critical concentration of zinc in the youngest emerged leaf and
grain for diagnosing zinc deficiency was 12 mg zinc/kg. However, when
relating the zinc concentrations in the youngest emerged leaf to the grain
yield (prognosis), a zinc concentration of 14 mg zinc/kg was determined.
Calcium-spray treatments for ameliorating albedo breakdown in navel oranges
Authors: Treeby M. T. , Storey R.
Published: September 2002

Albedo breakdown is a rind disorder of orange fruit that results in significant economic cost to the Australian citrus industry. The effectiveness of calcium sprays as a control measure for albedo breakdown of navel orange fruit was investigated in a series of experiments in which single fruit, 1 m2 quadrats of tree canopy or whole trees were treated with different calcium sprays. Repeated spraying (24×) of single Bellamy navel orange fruit throughout the season with 1% calcium solutions increased the proportion of unaffected fruit from 30 to 65-80%. Repeated applications (15×) of 1% calcium as CaCl2 and Ca(NO3)2 to quadrats increased the proportion of unaffected fruit from 43 to 70-95%. The effect of anion was in the order Ca(NO3)2 CaCl2 >CaCO3. Repeated spraying (15×) of a commercial CaCl2 formulation (Stopit) at a calcium concentration of 0.33% increased the proportion of unaffected fruit in quadrats from 17 to 47%. Generally, early and mid-season calcium sprays were equally effective and tended to be marginally better than late-season sprays. Spray-applications of calcium at a concentration of 0.33% were more effective than calcium sprays at 0.11% applied early in the season. Calcium sprays were less effective than gibberellic-acid sprays based on the number of sprays but calcium treatments did not affect rind quality characteristics such as rind colour; in contrast, gibberellic acid induced regreening of fruit. Calcium sprays (as CaCl2) applied early in the season at 0.33% caused unacceptable fruit drop. CaCl2 (0.33%�calcium) treatment (5×) resulted in leaf chloride concentrations as high as 100 mmol/L in leaf-tissue water (0.7% on dry weight basis) - a level sufficiently high to substantially reduce photosynthesis. Ca(NO3)2 is the preferred calcium source in citrus because it is (i) as or more effective than CaCl2, (ii) does not result in leaf damage and fruit drop and (iii) may provide a small controlled nitrogen supplement to leaves and fruits.
Starch degradation in 'Kensington' mango fruit following heat treatments
Authors: Jacobi K. K. , Hetherington S. E. , MacRae E. A.
Published: September 2002

Changes in carbohydrate metabolism of ‘Kensington’ mango fruit
from 2 major production regions in Queensland were measured after conditioning
fruit with hot air at 40°C for 0, 2, 4, 8 and 16 h or at 22°C for 16
h (control) followed by hot-water treatment at either 45°C fruit-core
temperature for 30 min or 47°C fruit-core temperature held for 15 min.
Advancing physiological maturity of ‘Kensington’ mango fruit was
correlated with increased starch concentration within the mesocarp. An
α-amylase inhibitor was present in unripe ‘Kensington’
mesocarp. α-Amylase activity was promoted by conditioning fruit at
40°C for 8 h, and this enhanced enzyme activity persisted until the fruit
were ripe. Consequently, starch degradation was accelerated and the
concentration of total soluble solids was higher in fruit conditioned at
40°C for 8 h than in fruit left at the lower temperature of 22°C for
16 h or not conditioned. Immediately on removal of fruit from hot-water
treatment, activities of α-amylase and phosphorylase were inhibited.
This inhibition was correlated with higher starch concentration and starch
layer and starch spot injuries in these fruit. A positive correlation was also
found between increased sucrose concentration and greater starch loss in
40°C conditioned ‘Kensington’ fruit. It is proposed that
increased sugar concentration in the mesocarp increased the level of fruit
heat tolerance.
Germination response to temperature in tropical and subtropical pasture legumes. 1. Constant temperature
Authors: McDonald C. K.
Published: September 2002

The germination response of 13 promising and commonly used tropical and subtropical legumes in northern Australia was tested in the laboratory at 10 constant temperatures ranging from 8 to 447deg;C. Total percent germination for most species was high at temperatures from 16 to 36°C, with Macroptilium atropurpureum, Lablab purpureus and Glycine latifolia germinating well at 12°C. Macroptilium atropurpureum and G. latifolia had less seed death than other species at 8°C. There was no germination at 8 or 44°C for any species. Optimum temperature for rate of germination ranged from 24°C for G. latifolia up to 36°C for Macroptilium bracteatum. Leucaena leucocephala showed a 12-degree range (24-36°C) of optimum temperatures for rate of germination, but most species had a range of 4-8°C. The ability to germinate at a broad range of temperatures indicates that the species are well adapted to northern Australia. Consideration of these responses could be useful in selection of future species or cultivars. Existing linear models with base, optimum and ceiling temperatures, and coefficients of germination rate above and below optimum temperature were tested to predict germination from thermal time. Predicted germination in real time explained 73-90% of the variation in observed germination, with the closeness of fit poor at temperatures distant from optimum. Models using a series of step-wise linear equations describing each 5% interval of germination explained over 99% of the variation in cumulative germination with time, but required a large number of parameters.
Factors affecting cane yield and commercial cane sugar in the Tully district
Authors: Lawes R. A. , Basford K. E. , McDonald L. M. , Lawn R. J. , Wegener M. K.
Published: September 2002

The Tully Sugar Mill has collected information about sugarcane supplied for crushing from every block in the mill district from 1970 to 1999. Data from 1988 to 1999 were analysed to understand the extent of the variation in cane yield per hectare and commercial cane sugar in the Tully mill area. The key factors influencing the variation in cane yield and commercial cane sugar in this commercial environment were identified and the variance components computed using a restricted maximum likelihood methodology. Cane yield was predominantly influenced by the year in which it was harvested, the month when the crop was ratooned (month of harvest in the previous year) and the farm of origin. These variables were relatively more important than variety, age of crop or crop class (plant crop, first ratoon through to fourth or older ratoons) and fallowing practice (fallow or ploughout-replant). The month-of-ratooning effect was relatively stable from year-to-year. Commercial cane sugar was influenced by the year of harvest, the month of harvest and their interaction, in that the influence of the month of harvest varied from year to year. Variety and farm differences were also significant but accounted for a much lower portion of the variation in commercial cane sugar. An empirical model was constructed from the key factors that influenced commercial cane sugar and cane yield to quantify their combined influence on sugar yield (t/ha). This may be used to assist mill personnel to predict their activities more accurately, for example to calculate the impact of a late finish to the current harvest season on the following year's crop.
Prospects for biological control of cutleaf mignonette, Reseda lutea (Resedaceae), by Baris picicornis and Bruchela spp. in Australia
Authors: Bailey P. , Sagliocco J-L. , Vitou J. , Cooke D.
Published: September 2002

In South Australia, Reseda lutea is abundant, invading
pastures and crops on calcareous soils while in its native Mediterranean range
it is uncommon in occurrence and is not reported as a weed of cultivated
crops. Its invasive behaviour in South Australia may be attributed to
vegetative growth of root fragments spread by cultivation, while propagation
by seed is of minor importance. Surveys in Spain, Portugal, Morocco, France,
Turkey and Israel indicated that agronomic differences, particularly depth of
cultivation and seeding rates of cereals may explain why it is not a crop weed
in these countries. Another difference is that plants in the region of origin
have an associated fauna not present in Australia. These potential biological
control agents include a root-boring weevil, Baris picicornis, flower- and
seed-feeding urodontids, Bruchela suturalis and
B. rufipes, and a leaf spot
pathogen,Cercospora resedae.
Baris picicornis was introduced from France and Turkey,
under quarantine, to Australia but laboratory specificity-testing demonstrated
that it could complete its life cycle on 2 commercially grown cultivars of
Brassica rapa (choy sum and Chinese cabbage). Because of
this, it is not proposed to release B. picicornis in
Australia at present. Bruchela suturalis was also
introduced into Australian quarantine from France but attempts to change its
annual life cycle to Southern Hemisphere seasons were not successful, and a
culture could not be established. Both Baris picicornis
and Bruchela spp. remain promising agents, and further
work on their introduction is justified by their potential for biological
control of R. lutea.
Effect of cover crops and cultural treatments on plant parasitic nematode density, fungal root disease severity and yield in white clover
Authors: Zahid M. I. , Gurr G. M. , Nikandrow A. , Hodda M. , Fulkerson W. J. , Nicol H. I.
Published: September 2002

Maize (Zea mays), sorghum
(Sorghum bicolor), rapeseed
(Brassica napus) and molasses grass
(Melinis minutiflora) were tested for their ability to
host clover root-knot nematodeMeloidogyne trifoliophila
in a glasshouse pot experiment and were found to be a poor hosts. A second
experiment determined the value of these plants as soil amendments in reducing
nematode numbers or improving white clover
(Trifolium repens) growth. The effects of these crops
together with a range of cultural treatments were also evaluated in a field
experiment at Wollongbar Agricultural Institute, New South Wales, Australia,
for their impact on nematode population and root rot disease severity. A
chopped shoot amendment of sorghum was effective
(P<0.05) in reducing the number of root galls and
eggs in white clover roots and improving plant growth in the pot test.
Overall, cover crop treatments, in particular molasses grass and maize,
reduced (P<0.01) field densities of
Heterodera trifolii but the population densities
recovered quickly after re-establishment of white clover pasture. Dry matter
yields were improved only up to 11 weeks after clover establishment. Although
cover crops showed potential for improving yield and in reducing the
population of certain nematodes, removal of white clover pasture for 5 months
as a management practice does not appear to be useful in overcoming root and
stolon rot diseases of white clover in this subtropical climate.
Effects of continuous grazing and seasonal closures on the performance and persistence of some sown temperate perennial grasses, North-West Slopes New South Wales
Authors: Lodge G. M.
Published: September 2002

A split-plot experiment was sown at Tamworth in 1992 to examine the effects of continuous sheep grazing and seasonal closures (autumn, spring, spring + autumn, and summer + winter) on the herbage mass, plant frequency and basal cover of 5 perennial grasses, when sown as monocultures or with a perennial (Trifolium repens cv. Haifa) or annual legume (Trifolium subterraneum var. subterraneum cv. Seaton Park). Plant basal area and crown density data were also collected. The perennial grasses were Phalaris aquatica cv. Sirosa, Festuca arundinacea, cv.� Demeter, Lolium perenne cv. Kangaroo Valley, Austrodanthonia richardsonii (syn. Danthonia richardsonii) cv.�Taranna, and A. bipartita (syn. D. linkii) cv. Bunderra.

There was no significant effect of legume presence on the herbage mass or persistence of the perennial grasses. The only treatment that had a significant effect (P< 0.05) on either herbage mass, plant frequency or basal cover data was the grazing treatment × perennial grass interaction in each of the years 1993-98, except for herbage mass in December 1993 and basal cover in October 1998. In all of the grazing treatments examined, Kangaroo Valley ryegrass failed to persist after spring 1994; Demeter fescue had failed by spring 1997 and Sirosa phalaris by spring 1998. Six years after sowing the only temperate grass cultivars that were persisting in all grazing treatments were the native perennials, Taranna and Bunderra. Hence, the data represent the entire stand life from sowing to eventual failure for the 3 introduced cultivars. While grazing treatment effects within years for individual species were significant, overall grazing had little effect on the rate of decline in herbage mass and persistence of Kangaroo Valley, Demeter and Sirosa. By 1998, grazing treatment had no significant effect on the herbage mass and basal cover of Taranna and Bunderra, but their plant frequencies were lowest in the spring rest and summer + winter rest treatments.
Response of Italian elite subterranean clover genotypes to Fusarium avenaceum and Fusarium oxysporum under artificial conditions
Authors: Piano E. , Riccioni L. , Pecetti L. , Carroni A. M. , Porta-Puglia A.
Published: September 2002

Breeding programs of subterranean clover in southern Europe have traditionally set low priority on selection against major pathogens, in part because there have been no major disease outbreaks in this region. However, root-rot causing fungi, such as Fusarium spp., occur frequently on other crops and can therefore also represent a threat to clover. Thus, the breeding program carried out in Sardinia, Italy, took note of this disease. This study reports the results of 2 trials carried out in 2 consecutive years following artificial infestation with Fusarium spp. The first trial included 45 genotypes, of which 37 were Sardinian lines under advanced breeding and 8 were commercial varieties. To validate the variation observed in disease response, a subset of 27 genotypes was further evaluated in the second trial. In both trials, 3 pathogen treatments were applied, in addition to a control, uninoculated treatment - F. avenaceum, F. oxysporum, and an equal mixture of both fungi. One-month-old clover seedlings were scored in all treatments for shoot-growth vigour (1-9 scale), then excavated for scoring root-rot symptoms (1-5�scale), and finally weighed after oven drying. Analysis of variance tested differences among treatments, among genotypes, and between subsp. subterraneum and brachycalycinum of Trifolium subterraneum. On the common set of genotypes to both trials, a cluster analysis was applied using, as original variables, the average disease score across the 3 inoculated treatments in the 2 trials. Confirming previous evidence, F. avenaceum proved more pathogenic than F. oxysporum. The results suggested that high seedling vigour may play a role in limiting root-rot effects, and this may also contribute to the relatively better tolerance of subsp. brachycalycinum over subsp. subterraneum observed. Despite some inconsistency of response in the 2 trials both at the treatment and genotype level, some Sardinian genotypes demonstrated a consistent level of tolerance especially in relation to the performance of the commercial varieties tested. Among them were the lines `125 brachy C', `56 sub D', `22 brachy G', `56 sub B' (=Campeda), and `19 brachy E' (=Antas).
Productivity and persistence of Trifolium hirtum, T. michelianum, T. glanduliferum and Ornithopus sativus sown as monocultures or in mixtures with T. subterraneum in the south-eastern Australian wheat belt
Authors: Dear B. S. , Wilson B. C. D. , Rodham C. A. , McCaskie P. , Sandral G. A.
Published: September 2002

The persistence and productivity of 5 annual pasture legume species: French serradella (Ornithopus sativus Brot) cv. Cadiz; rose clover (Trifolium hirtum All.) cv. Hykon; balansa clover (T. michelianum Savi) cv.�Frontier; gland clover (T. glanduliferum) cv. Prima) and subterranean clover (T. subterraneum L.), grown in monocultures or as binary mixtures with subterranean clover cv. Nungarin, were examined on an acid soil (pH�4.7) in the low rainfall wheat belt of south-eastern Australia over a 3-year period of continuous pasture.
PROGRAZE - an extension package in grazing and pasture management
Authors: Bell A. K. , Allan C. J.
Published: September 2002

Grazing management decisions by beef cattle
and sheep producers in south-eastern Australia have tended to be influenced
more by the needs of livestock, often with little consideration given to the
possible short- or long-term production impacts that the duration or intensity
of grazing may have on pastures. This is partially due to inadequate knowledge
of these impacts on some pasture types. Grazing decisions relating principally
to livestock tend to be based on a subjective appraisal of liveweight change
and pasture assessments often with inadequate understanding of critical
pasture characteristics influencing livestock production or the ability to
assess these characteristics.
PROGRAZE is an extension package developed to assist beef cattle and sheep
producers improve the quality of grazing management decision making so they
more efficiently and effectively achieve their production and market targets
for livestock and livestock products while maintaining or improving the
productivity and sustainability of their pastures.
To measure knowledge change, PROGRAZE participants were surveyed before they
commenced the course and again at its conclusion. To measure on-farm adoption
of the skills and knowledge contained within PROGRAZE, participants were again
surveyed about 12 months after completing the course. Five focus groups were
conducted as a means of obtaining direct feedback from a range of participants
on issues not adequately addressed through the surveys.
The surveys showed the most significant area in knowledge change by
participants was associated with pasture quality and the influence of pasture
characteristics on pasture intake and livestock prodution. There was strong
evidence of practice change by participants particularly, grazing decisions
associated with pasture management. When asked whether participation in
PROGRAZE had resulted in increased financial returns from their grazing
enterprise, 89% replied it had and 91% indicated participation
would lead to more sustainable pastures. The overall response to PROGRAZE was
positive with 59% of those producers who replied to the survey
indicating it exceeded or completely met their expectations and another
36% stating that it had mostly met expectations. Ninety-nine percent of
respondents indicated that they would recommend PROGRAZE to fellow producers.
Shoot mineral composition and yield of wheat genotypes grown on a sodic and a non-sodic soil
Authors: Liu C.-Y. , Paull J. G. , Rathjen A. J.
Published: September 2002

A collection of wheat lines including 49
overseas and 35 Australian lines was grown in a 3-replicate randomised block
design experiment at 2 sites (Two Wells and Roseworthy Campus, South
Australia) during the 1994 growing season (June–December 1994). The aim
of this investigation was to determine if elemental nutrients could be
implicated in response to soil sodicity tolerance of wheat. Large grain yield
differences and mineral concentrations were evident among different varieties
including those from Australia. Several mineral concentrations in shoot,
including manganese, potassium, sodium, phosphorus, boron, zinc and copper,
taken up by these plants were correlated significantly with grain yield. The
detrimental effects of sodium and boron concentrations on grain yields were
less for local varieties than the overseas lines, because of lower average
shoot concentrations and lower coefficients of variation associated with the
Australian varieties. The grain yield reduction at a sodic site appeared to be
due to both soil physical changes and nutritional changes, with the combined
effects of nutrient deficiencies and toxicities accounting for 23% of
the variation. Except for the large differences of boron and sodium
concentrations, there appeared to be a similar magnitude of variability
between the overseas wheat collection and the Australian wheats. The present
study confirmed that the tetraploid and hexaploid wheats differ in sodium
concentration or potassium : sodium ratio, in addition to other nutrient
changes including potassium, manganese, magnesium and copper. However, sodium
concentration (or potassium : sodium ratio) and boron were not sufficient
enough to explain the variability in grain yield of all the Australian wheats
studied, suggesting that other factors detrimental to wheat production in
sodic soils need to be identified.
Effect of applied phosphorus on the growth of Lupinus luteus, L. angustifolius and L. albus in acidic soils in the south-west of Western Australia
Authors: Bolland M. D. A. , Sweetingham M. W. , Jarvis R. J.
Published: September 2002

Phosphorus is the major nutrient element
deficiency of grain legumes in the south-west of Western Australia.
Lupinus angustifolius is the major grain legume grown on
the acidic soils in Western Australia. However,
L. luteus and L. albus are being
researched as possible alternatives because of tolerance to diseases and
specific soil type adaptation. The fertiliser phosphorus requirements of
L. luteus and L. albus in acidic
soils of Western Australia are not well known. By contrast, there is much
information on the phosphorus requirements of
L. angustifolius in these soils where placement of
fertiliser phosphorus has been found to be important. Three field experiments
were undertaken on different acidic soils in Western Australia (sand, sandy
loam, and loamy sand) to compare how L. luteus cv. Teo
and L. angustifolius cv. Merrit use fertiliser
phosphorus, applied by different methods as superphosphate.
Lupinus albus cv. Kiev Mutant, which is not adapted to
the sandier soils, was included at the loamy sand site. In 2 experiments on
the loamy soils, the phosphorus was either placed with the seed (drilled) or 8
cm below the seed while sowing seed at 5 cm (banded). In the experiment on
sand, the phosphorus was either spread over the soil surface immediately in
front of the seeding tines (topdressed) or banded below the seed.
Compared with L. angustifolius: (i) for the 2 loamy
soils, L. luteus used phosphorus more effectively for
producing dried shoots, but was less effective at using phosphorus for
producing seed (grain); (ii) for the loamy sand,
L. albus was less effective at using the phosphorus for
producing dried shoots and grain, except it was about equally effective for
producing grain when the phosphorus was banded below the seed. For the sandy
soil, L. luteus produced no grain yield response whereas
L. angustifolius showed an about 20% yield
response to the added phosphorus, and both methods of application were about
equally effective. Phosphorus banded below the seed was more effective than
phosphorus drilled with the seed for producing dried shoots and grain of
L. albus on the loamy sand and for grain only of
L. luteus on the sandy loam. Both methods of phosphorus
application were about equally effective for producing dried shoots and grain
of L. angustifolius and grain of
L. luteus on the loamy sand. Fertiliser drilled with the
seed was more effective than banded fertiliser for producing dried shoots and
grain of L. angustifolius on the sandy loam and dried
shoots of L. luteus on the loamy sand and sandy loam.
The concentration of phosphorus in grain of L. luteus
was consistently about double that found in grain of
L. angustifolius. The concentration of manganese in
dried shoots of L. albus was 3–5 times higher than
in the other 2 species.
The use of qualitative airborne multispectral imaging for managing agricultural crops - a case study in south-eastern Australia
Authors: Lamb D. W.
Published: September 2002

Charles Sturt University has operated an airborne multispectral imaging system
as a research support and management tool over south-eastern Australian crops
since 1994. Our experiences have demonstrated the utility, timeliness and
cost-effectiveness of qualitative multispectral imagery for monitoring and
managing spatial variability in a range of agricultural crops, yet to date the
technology remains underutilised in Australia. Images showing variations in
the texture of soils in paddocks are a useful indicator of the location of
different soil zones for soil sampling, and can assist in siting of treatment
plots within paddocks. Multispectral imagery can be used for a synoptic
assessment of early weed pressure in fallow paddocks or seedling crops.
Locating variability in crop emergence and, later, canopy vigour and biomass,
are all potentially means of undertaking precision farming without the capital
investment associated with yield mapping. However, like any remote monitoring
tool, follow-up ground-truthing must always be used to establish or confirm
the causes of observed variability. The use of the technology as part of a
greater data acquisition strategy is recommended.
Effect of pre-harvest applications of an antitranspirant and vegetable oil on cracking and size of cherry (Prunus avium L.) cv. Van fruit
Authors: Granger A. R. , Traeger D. R. C.
Published: September 2002

A 1% solution of antitranspirant and a 0.3% solution of
vegetable oil were applied to cherry trees before rainfall during the 3 weeks
preceding harvest to evaluate their efficacy in reducing fruit damaged by
cracking in field experiments in South Australia from 1993 to 1998. Between 2
and 14% of fruit were cracked on untreated trees during this period.
From 6 to 10% less cracked fruit were found in 2 of the 5 seasons
following the application of antitranspirant and oil sprays. In the other 3
seasons, levels of cracked fruit were not significantly different between
treatments. In the 2 driest seasons, treatment with oil or antitranspirant
resulted in larger fruit than on untreated trees, and as in previous studies
this was thought to be a result of reduced water loss. In 4 years, total
soluble solids content of fruit were similar in all treatments, but in
1996–97 controls had significantly higher sugar levels than the treated
fruit. This being the driest year during the study, it is thought that greater
water loss occurred on controls leading to a higher concentration of total
soluble sugars. Material costs of oil at A$96/ha per application is
less, compared with antitranspirant that cost $4000/ha per
application.
Lot-fed goats - the advantages of using an enriched environment
Authors: Flint M. , Murray P. J.
Published: September 2002

By reducing the stress associated with high stocking density in a feedlot it
is likely that goats will utilise their feed more efficiently and suffer fewer
health problems. One possible method of reducing stress is to enrich the
feedlot environment. In a feedlot of 160 castrated goats (average weight 24.6
± 2.6 kg), 2 types of feedlot structures were compared; a
typical feedlot and an ‘environmentally enriched’ feedlot, and
goats stocked at 2 densities; a high stocking density (1667 goats/ha) and
a relatively low stocking density (897 goats/ha). Over a 42-day period,
environmental enrichment (old car/truck tyres and wooden railway sleepers
to climb on and PVC piping to mouth and butt) increased weight gain by
83% (P = 0.04) and reduced the
occurrence of inanition by 36%. Aggressive behaviour at the feed trough
was reduced by 30% (P = 0.03) in pens
of lower density when compared with pens of higher density. We conclude that
lot feeding goats in environmentally enriched surroundings will increase feed
conversion and reduce the number of non-eaters when compared with typically
bare pen structures. Doubling in liveweight gain of goats within enriched
feedlot surroundings when compared with typical structures shows promise as a
cost effective, animal-welfare-orientated practice.
Using yield maps and intensive soil sampling to improve nitrogen fertiliser recommendations from a deterministic model in the Western Australian wheatbelt
Authors: Adams M. L. , Cook S. , Bowden J. W.
Published: September 2002

A field-scale experiment was conducted to determine the ability of a
deterministic model developed for Western Australian wheat farmers to guide
site-specific applications of nitrogen fertiliser. The results indicated that
site-specific information of achievable yield improved the prediction accuracy
much more than information about soil nitrogen — even though the
latter was more costly to acquire. When applied together, these sources of
information improved the prediction accuracy of the model markedly, explaining
about half of the variation of yield response to nitrogen. However, the model
failed to explain a substantial portion of site-specific variation, even with
this intensity of information. This failure indicates the difficulty of
representing complex biological systems with simple functional models.