Journal articles on the topic 'Condobolin'
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1
Milthorpe, PL, and PR Dann. "Production from tagasaste (Chamaecytisus palmensis) at four contrasting sites in New South Wales." Australian Journal of Experimental Agriculture 31, no. 5 (1991): 639. http://dx.doi.org/10.1071/ea9910639.
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In 1985, experiments were conducted at 4 localities in south-eastern and central New South Wales, to assess the production potential of tagasaste. The results were disappointing: 2 experiments failed to establish because of soil waterlogging, while production from the other 2 sites was only intermittent. Annual dry matter production did not exceed 3 t/ha at Condobolin or 5 t/ha at Yass. Although survival of established plants was good, production was limited by prolonged dry periods at Condobolin and by low temperatures during winter at Yass. Tagasaste is costly to establish (up to $A500/ha) and difficult to manage. In our environments, conventional pastures or fodder crops which require simpler management would probably out-produce tagasaste at most times during the experimental period.
2
Henzell, R. "Eye-Lens Weight as an Indicator of Age in Australian Goats, Capra-Hircus L." Wildlife Research 14, no. 1 (1987): 69. http://dx.doi.org/10.1071/wr9870069.
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The age in days of goats from Canegrass Station, S.A., and Condobolin, N.S.W., can be estimated from their paired dry eye-lens weights (E, in grams) by the formula: A = (357.5+46 lnE)/(0.002714-InE), where A is age since conception. The formula is based mainly on the eye-lens weights of 88 feral goats from Canegrass whose ages had been estimated by a method based on reproductive patterns. These data were supplemented by the lens weights of 20 known-age domestic goats from Condobolin. The formula incorporates an adjustment to reduce statistical bias. The lenses in goats from Avenue Range, S.A., grew at a different rate. The relationship between eye-lens weight and age was not influenced by differences in sex or rate of body growth.
3
Eppleston, Jeffrey, Douglas J. Begg, Navneet K. Dhand, Bruce Watt, and Richard J. Whittington. "Environmental Survival of Mycobacterium avium subsp. paratuberculosis in Different Climatic Zones of Eastern Australia." Applied and Environmental Microbiology 80, no. 8 (January 24, 2014): 2337–42. http://dx.doi.org/10.1128/aem.03630-13.
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ABSTRACTThe duration of survival of both the S and C strains ofMycobacterium aviumsubsp.paratuberculosisin feces was quantified in contrasting climatic zones of New South Wales, Australia, and detailed environmental temperature data were collected. Known concentrations of S and C strains in feces placed on soil in polystyrene boxes were exposed to the environment with or without the provision of shade (70%) at Bathurst, Armidale, Condobolin, and Broken Hill, and subsamples taken every 2 weeks were cultured for the presence ofM. aviumsubsp.paratuberculosis. The duration of survival ranged from a minimum of 1 week to a maximum of 16 weeks, and the provision of 70% shade was the most important factor in extending the survival time. The hazard of death for exposed compared to shaded samples was 20 and 9 times higher for the S and C strains, respectively. Site did not affect the survival of the C strain, but for the S strain, the hazard of death was 2.3 times higher at the two arid zone sites (Broken Hill and Condobolin) than at the two temperate zone sites (Bathurst and Armidale). Temperature measurements revealed maximum temperatures exceeding 60°C and large daily temperature ranges at the soil surface, particularly in exposed boxes.
4
Hochman, Z. "Quantifying vernalization and temperature promotion effects on time of flowering of three cultivars of Medicago truncatula Gaertn." Australian Journal of Agricultural Research 38, no. 2 (1987): 279. http://dx.doi.org/10.1071/ar9870279.
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The interaction of vernalization and high temperature promotion on the flowering time of three Medicago truncatula cultivars is examined. A previous model describing these processes is modified to account for the hypothesis that temperature promotion of flowering is subsequent to full vernalization. Both models are calibrated to minimize errors in predicting flowering dates from field observations at Condobolin and Tamworth in New South Wales. The calibrated models are then tested on data from other seasons and locations. The implications of the modified model are discussed with regard to an ideotype and to improved efficiency in agronomic evaluation of genetic material.
5
Little, IP, CJ Chartres, and RR Young. "The relationship of soil properties to the growth of barrel medic at Condobolin, New South-Wales." Soil Research 30, no. 3 (1992): 371. http://dx.doi.org/10.1071/sr9920371.
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Poor growth of barrel medic (Medicago truncatula) has been observed in established pasture on the red duplex and gradational soils of the semi-arid sheep and wheat growing areas of western New South Wales. Red-brown earth soils were examined from three paddocks on Condobolin Research and Advisory Station in conjunction with a visual assessment of the growth of medic. The soils were sampled at 20 m intervals along three line transects in each of three paddocks with different cropping histories. Bray-P; pH, Mn and Al extracted by 0.01 M CaCl2; exchangeable plus soluble Na, K, Ca and Mg; and pH in a 1:5 soil/water suspension were measured at four depth increments at each sampling point. Although the pH in CaCl2 was often less than 5.0, in general no Al was extracted from the 0-5 cm soil layer. Classification of the soils on medic growth alone showed medics were absent from the most acid soils. However, there was considerable within class variability. A better approach was provided by classifying the soils by means of a Euclidean distance/flexible sort of scores from the first principal component. This classification showed that the poorest medic growth was associated with the most acid group with considerable amounts of Al soluble in 0.01 M CaCl2 in the 10-20 cm horizon. Medics grew best in soils with moderate pH values between 5 and 6 in CaCl2 where there was no soluble A1 and moderate levels of exchangeable Ca and Na and soluble Mn. Medics appeared also to grow less well in more alkaline soils where there was very little soluble Mn. There were no differences between classes in available P. There were differences between paddocks; the uncultivated paddock being the most acid and the paddock with the longest cropping history having more Bray-P, more exchangeable Na and more exchangeable Ca at 10-20 cm. The uncropped paddock became more acid and the base status was lowered by natural soil processes and its condition probably indicates the status of many such soils in the district.
6
Young, RR, PH Croft, and GA Sandral. "Variation in flowering times and agronomic characteristics of Medicago laciniata (L.) Miller collected from diverse locations in New South Wales." Australian Journal of Experimental Agriculture 32, no. 1 (1992): 59. http://dx.doi.org/10.1071/ea9920059.
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Thirty-two accessions of Medicago laciniata (L.) Miller collected from throughout western New South Wales and 1 from southern Queensland, 4 accessions of M. minima (L.) Bartalini, 1 of M. polymorpha L., and 3 cultivars of M. truncatula Gaertner were grown in rows at Condobolin over 2 years. There were no significant differences between the M. laciniata accessions for flowering time, dry matter score, seed yield, pod weight, and seed weight in either year. No differences were detected in plant or pod morphology. This lack of variation means that any accession may be used as parent material for a breeding program to reduce pod spine and potential to contaminate wool. Should absence of phenotypic variation be indicative of no genotypic difference, it follows that all the M. laciniata accessions had a common origin.
7
Fettell, NA, and HS Gill. "Long-term effects of tillage, stubble, and nitrogen management on properties of a red-brown earth." Australian Journal of Experimental Agriculture 35, no. 7 (1995): 923. http://dx.doi.org/10.1071/ea9950923.
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Differences in soil organic carbon (C), total nitrogen (N), and pH resulting from 14 and 15 years of different tillage, stubble, and fertiliser N management practices were measured for a red-brown earth at Condobolin in western New South Wales. The 5 main treatments comprised stubble burning or retention in factorial combination with cultivation and direct drilling, and stubble incorporation combined with cultivation. Two rates of N fertiliser (0 and 40 or 50 kg/ha) were applied annually, and wheat was grown each year. There were no significant differences between tillage and stubble treatments for soil organic C, total N, or pH. Fertiliser N application caused small but significant increases in organic C and total N but decreased the pH of the surface 2.5 cm of soil by 0.4-0.5 units compared with the nil fertiliser rate. The study indicates that direct drilling and stubble retention with continuous wheat have had little long-term effect on soil organic C and total N in this low rainfall environment.
8
Santonoceto, C., P. J. Hocking, J. Braschkat, and P. J. Randall. "Mineral nutrient uptake and removal by canola, Indian mustard, and Linola in two contrasting environments, and implications for carbon cycle effects on soil acidification." Australian Journal of Agricultural Research 53, no. 4 (2002): 459. http://dx.doi.org/10.1071/ar01096.
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Field studies of the oilseed crops canola, Indian mustard, and linseed/Linola were conducted over 2 seasons at 2 contrasting sites in the cropping regions of central and southern NSW to determine the uptake of mineral nutrients and quantities removed in seed. The sites were in the Junee region where production of these oilseeds is common, and at Condobolin, which is regarded as marginal for production of the crops. The 2 rates of nitrogen (N) fertiliser applied were either none or rates that growers in the Condobolin and Junee regions would apply to achieve high seed yields after a cereal crop in the rotation when soil mineral N is low. Concentrations of total N, the major cations (K, Ca, Mg, Na) and major anions (P, S, Cl), and the micronutrients Fe, Mn, Zn, and Cu were determined in shoots harvested at flowering and maturity. Nitrate and sulfate were also measured, and estimates were made of excess cation concentrations in the plant material. The ranges of concentrations of excess cations in shoots of the oilseeds at flowering were 83–206 cmolc/kg and 43–121 cmolc/kg for straw at maturity. Linola had lower concentrations of excess cations in vegetative material (83–108 and 43–82 cmolc/kg at flowering and maturity, respectively) than canola or Indian mustard. Concentrations of excess cations in seed of the crops were lower than for vegetative material, and ranged from 30 to 49 cmolc/kg. Nitrogen fertiliser had relatively little effect on concentrations of mineral nutrients or excess cations in either shoots at flowering and maturity, or in seed. However, N fertiliser increased the growth and seed yields of the crops, and thus the amounts of mineral nutrients and excess cations in shoots and seed. The results are discussed in the context of the depletion of soil nutrients due to their removal in harvested seed of the N-fertilised crops. The contribution of excess cation removal in seed to soil acidification is also discussed. It is estimated that the quantity of lime required to neutralise the acidity resulting from removal of 1 t seed is 22.4 kg for canola, 17.0 for Indian mustard, and 20.8 for linseed/Linola. Estimates of the relative contributions of seed removal and N fertiliser to soil acidification are presented.
9
Evans, C. M., N. A. Fettell, and J. Brockwell. "Populations of Sinorhizobium meliloti congregate in the 30 - 60 cm section of the soil profile in a stand of dryland lucerne (Medicago sativa): is this where lucerne fixes its nitrogen?" Australian Journal of Experimental Agriculture 45, no. 3 (2005): 225. http://dx.doi.org/10.1071/ea03149.
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Lucerne (Medicago sativa L.) cv. Hunterfield was inoculated with Sinorhizobium meliloti and sown in a red clay loam at Condobolin, New South Wales. The soil had been limed at 6 different rates 8 years previously. In 2001, when the stands were 3 years old, the populations of S. meliloti were enumerated, with a plant-infection test, in 4 sections of the soil profile (i.e. 0–15 cm, 15–30 cm, 30–60 cm and >60 cm). The numbers of rhizobia in the soil were very high (120 000 rhizobia/g) in the 30–60 cm section. In sharp contrast, much lower numbers (0–15 cm, 75 rhizobia/g; 15–30 cm, 190 rhizobia/g; >60 cm, 287 rhizobia/g) were detected in the other sections of profile. Liming had no effect on size of S. meliloti population. It was concluded that, under the conditions of the experiment, it was reasonable to assume that lucerne nodulated most abundantly between 30–60 cm below ground. This zone may represent the location of maximum nitrogen fixation. Some implications of the conclusions are discussed.
10
Mwendwa, James M., William B. Brown, Jeffrey D. Weidenhamer, Paul A. Weston, Jane C. Quinn, Hanwen Wu, and Leslie A. Weston. "Evaluation of Commercial Wheat Cultivars for Canopy Architecture, Early Vigour, Weed Suppression, and Yield." Agronomy 10, no. 7 (July 9, 2020): 983. http://dx.doi.org/10.3390/agronomy10070983.
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Herbicide resistance in weeds restricts control options, thereby escalating economic loss and threatening agricultural sustainability in cereal production. Field evaluation of the crop performance, competitive traits, and consequent weed suppressive potential of 13 commercial winter wheat (Triticum aestivum L.) cultivars was performed in central NSW Australia with a focus on the evaluation and modelling of above-ground interactions. In 2015 and 2016, replicated field trials were established with genetically diverse commercial wheat genotypes under moderate to low rainfall conditions in Wagga Wagga (572 mm) and Condobolin (437 mm) New South Wales, respectively. The heritage cultivar Federation and a commercial cultivar of winter cereal rye (Secale cereale L.) were included as known weed-suppressive controls. Crop and weed growth, as well as early vigour, leaf area index, and photosynthetically active radiation, were monitored at various crop phenological stages including early growth, vegetative, flowering, grain fill, and harvest. Significant differences between wheat cultivar and location were observed for crop biomass, early vigour, leaf area index, weed number, weed biomass, canopy architecture, and yield in both 2015 and 2016. Differences in weed establishment were largely impacted first by rainfall and season and secondly by crop architecture (i.e., height, size, canopy) and phenology (i.e., growth stages). Early vigour and early canopy closure were instrumental in suppressing weed establishment and growth. Cultivar performance and competition with weeds were also clearly influenced by both environmental factors and genotype, as evidenced by differences in early cultivar performance, yield, and weed suppression by season and location. Specifically, Federation, Condo, and Janz wheat cultivars were superior performers in terms of weed suppression in both locations and years; however, Federation produced up to 55% lower yield than recently introduced cultivars. Partial least squares (PLS) regression was performed to develop a predictive linear model for weed competition in commercial wheat cultivars based on weed dry biomass as the response variable and selected aboveground crop canopy traits as predictors. In 2015, the model differed in accordance with crop growth stage, but the impact of predictors on weed biomass at both locations was not significant. In 2016, under local above average rainfall conditions, the model showed a significant negative correlation (p < 0.001) of most predictors on weed biomass (r2 = 0.51 at Condobolin, r2 = 0.62 at Wagga Wagga), suggesting the most influential factors in reducing weed numbers and establishment as crop vigour, biomass, and height. Our results indicate the establishment of competitive wheat cultivars in the absence of post-emergent herbicides resulted in a two to five-fold increased weed suppression over less suppressive genotypes, without significant yield penalties. Therefore, cultivar choice constitutes a cost-effective and sustainable weed management tool, particularly when weed pressure is significant.
11
Gomez-Macpherson, H., and RA Richards. "Effect of sowing time on yield and agronomic characteristics of wheat in south-eastern Australia." Australian Journal of Agricultural Research 46, no. 7 (1995): 1381. http://dx.doi.org/10.1071/ar9951381.
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The main environmental constraints to the yield of dryland wheat in south-eastern Australia are: a low and erratic rainfall throughout the growing season, the chance of frost at flowering time, and high temperatures during the grain-filling period. The aims of this work were threefold. Firstly, to determine which sowing period minimizes these constraints and results in the highest yields. Secondly, what is the optimum flowering time for a given sowing date so that maximum yield is achieved. The third aim was to determine whether any crop characteristic was associated with high yield or may limit yield in the different sowings. The experiments were conducted at three sites in New South Wales that were representative of dry (Condobolin) and cooler and wetter (Moombooldool, Wagga Wagga) sites in the south-eastern wheatbelt. In this study several sets of isogenic material, involving a total of 23 genotypes, that were similar in all respects except for flowering time, were sown early (mid-April and early May), normal (mid to late May) and late (June to mid July). Characteristics of the highest-yielding lines in each experiment are presented. The average flowering time of the highest yielding lines in all sowings had a range of only 12 days at the driest site, but a range of over 20 days at the coolest and wettest site. The optimum anthesis date (day of year, y) was related to sowing date (day of year, doy) at the cooler sites such that: y = 245+0.32 doy (r2 = 0.86) and at Condobolin, y = 253+0.19 doy (r2 = 0.91). Optimum anthesis date expressed in thermal time (�C days) after sowing (y) was related to sowing time (doy) as follows: y = 2709 -8-3 doy (r2 = 0.84). It is suggested that these relationships are likely to be quite robust and should hold true for similar thermal environments in eastern Australia. There was little variation in grain yield between the earliest sowing in mid-April (108 doy) and sowings throughout May (up to 147 doy). Grain yield declined 1.3% per day that sowing was delayed after late May. Aboveground biomass was substantially higher in early sown crops. However, this did not translate into higher yields. From the evidence presented it is argued that the principal reason that greater yields were not obtained in the early sowings, particularly in the April sowing, was the greater competition for assimilates between the growing spike and the elongating stem. It is suggested that a way of overcoming this competition is to genetically shorten the stems of winter wheats. This should capitalize on the considerable advantages in terms of water use efficiency that early sowing offers and result in greater yields. Barley yellow dwarf virus, although present at the cooler, wettest site in one year, was more frequent in the later sowings than in the early sowing and was not likely to have contributed to the lower than expected yields in the early sowings.
12
Milthorpe, PL, and RL Dunstone. "The potential of jojoba (Simmondsia chinensis) in New South Wales. 2. Some factors affecting yield." Australian Journal of Experimental Agriculture 29, no. 3 (1989): 389. http://dx.doi.org/10.1071/ea9890389.
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A jojoba (Simmondsia chinensis [Link] Schneider) stand at Condobolin. N.S.W.. established from a range of plant material, exhibited great variability in a number of plant characteristics including seed yield. Observations over 4 years indicated that a high bud to node ratio is necessary for high yield. Different lines varied from 44 to 74% in this ratio in the fourth year of study. The survival of buds to form open flowers varied greatly between lines and from year to year. Death of flower buds before opening was attributable to frost damage. Buds swelled as early as June in some lines while others showed no sign of swelling until September. In those lines with early swelling or flower opening a high proportion of the buds were frost damaged, whereas late flowering lines had a high rate of survival. Terminal flower buds formed just prior to winter dormancy survived and flowered in the next spring, even in otherwise early flowering lines. Earlier work has shown that jojoba flower buds remain dormant until a chilling requirement has been met. Jojoba lines should have a long chilling requirement to maintain dormancy in the buds until the danger of frosts is past. Almost all of the flowers that opened set fruit, indicating that pollination is not a problem in the New South Wales environment.
13
Fraser, Mark A., and Brendan J. Scott. "Variability of acidity in agricultural soils—the impact of timber burning at land clearing." Soil Research 49, no. 3 (2011): 223. http://dx.doi.org/10.1071/sr10076.
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Patchiness in the growth of barrel medic, Medicago truncatula, in the central west of New South Wales, near Condobolin, has been associated with variability of soil acidity. There is evidence of the effect of timber burning on soil properties and it is possible that such burning of timber stacks and windrows on land recently cleared for agriculture may add alkali and contribute to such pasture growth. Of the three sites used, two were already in a 20-year farming system and one was constructed in a recently cleared paddock. Soil sampled at the 0–0.10, 0.10–0.20, and 0.20–0.30 m soil depths indicated significant increases in soil pHCa and extractable Ca to a soil depth of at least 0.20 m for up to 20 years after timber had been burnt. The effect of the timber burn on soil chemistry was due to the conversion of alkali oxides to either hydroxides or carbonates. This addition of alkali moved relatively rapidly through the soil profile in a low-rainfall farming system. Additional alkali was found in the soil, mainly at the 0–0.10 m depth, in the form of free lime. Using assumed rates of soil acidification, the burn effect could persist for up to 1227 years before reverting to the pre-burn soil pH. It was also found that timber burning at the sites contributed to the spatial variability of soil acidity.
14
Johnston, WH. "Palatability to sheep of the Eragrostis curvula complex. 4. Dry matter production, feed value and persistence of a range of taxa." Australian Journal of Experimental Agriculture 29, no. 4 (1989): 533. http://dx.doi.org/10.1071/ea9890533.
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Productivity, nutritive value and persistence of a range of taxa of Eragrostis curvula complex were evaluated in experiments at Wagga Wagga, Temora, Condobolin and Orange, N.S.W. No relationships were found between previously determined palatability ranks and nitrogen (N) content, acid detergent fibre, digestible dry matter (DDM) or metabolisable energy. The nutritive value of stem was lower than leaf; however, if stem is well grazed this is unlikely to affect animal performance. Mean digestible dry matter and nitrogen contents of the E. curvula accessions were similar in the Wagga Wagga (a total of 8 determinations) and Orange (4 determinations) experiments (overall means, DDM = 57.48% and N = 1.65%), but digestibility was depressed in summer by 3.38 units (54.85 v. 58.23% in autumn) for leaf and 2.3 units (53.98 v. 56. 28%) for stem in the Orange experiment, and 4.68 units (56.43 v, 61.11% in spring) for leaf and 8.35 units (49.96 v. 58.31%) for stem in the Wagga Wagga Naturalised Accessions trial. In practice, this would be offset by increasing availability of palatable forage. Except for 1 occasion with stem, the nitrogen concentrations of the herbage (leaf N 2.02-1.45%, stem N 0.79-1.95%) were sufficient not to limit intake. Differences in persistence and dry matter yield indicated that, of the palatable lines, accession 4663 was better adapted to drier situations than 4650, and that accession 4660 was intermediate between the two. It is concluded that the palatable accessions were potentially useful pasture plants for south-eastern Australia.
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Roesner, E. A., N. A. Fettell, and J. Brockwell. "Liming and choice of pasture species improve rhizobial persistence in an acidic chromosol (red-brown earth)." Australian Journal of Experimental Agriculture 45, no. 3 (2005): 247. http://dx.doi.org/10.1071/ea03153.
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An experiment was conducted to determine the persistence of soil root-nodule bacteria as influenced by different rates of lime and the previous pasture species. The work was done at Condobolin, central-western New South Wales, on a chromosol (red-brown earth), acidic in the upper profile (pHCa 4.6), which was representative of soils for an extensive region of the eastern Australian wheat belt. In autumn 1997, the experimental area was treated with 4 rates (6.0 t/ha, 3.0 t/ha, 1.5 t/ha, nil) of finely-ground agricultural limestone and sown with 5 pasture species: lucerne (Medicago sativa), barrel medic (M. truncatula), subterranean clover (Trifolium subterraneum), rose clover (T. hirtum) and ryegrass (Lolium rigidum). The pastures were removed with herbicide and cultivation in September 2000. The land lay fallow for 9 months and then was sown to wheat (Triticum aestivum) in autumn 2001 and again in autumn 2002. The most probable numbers of soil (0–10 cm) populations of the root–nodule bacterium for Medicago species (Sinorhizobium meliloti) and for the Trifolium species (Rhizobium leguminosarum bv. trifolii) were counted in May 2001 and May 2002. Soil pH, which was significantly (P<0.05) elevated 12 months after liming, declined substantially during the next 4 years although there was no concomitant decline in the pH of unlimed soil. The pasture species were highly productive of both pasture dry matter and nitrogen. The majority of legume pasture nitrogen was a consequence of symbiotic nitrogen fixation. There was a small but significant (P<0.05) dry matter response to application of lime in lucerne and barrel medic, and a larger nitrogen response to liming in lucerne, barrel medic and rose clover. Nitrogen fixation by rose clover appeared suboptimal. It was assumed from the density of plants that large populations of rhizobia developed in the soil during the growth of the legumes. Nine months after removal of the pasture, rhizobia numbers had fallen to low levels but did not fall further during the following year. The initial fall was attributed to high soil temperatures and low soil moisture during the Condobolin summer. The population of rhizobia for Trifolium species was about twice that of the rhizobia for Medicago species but the difference was not statistically significant. Liming had an overriding influence on the size of rhizobial populations, except in plots that had previously grown ryegrass where numbers remained low irrespective of rate of liming. Overall, most probable numbers escalated with each increase in rate of liming, from 10/g soil in the nil lime plots to 708/g in the 6 t/ha lime plots. The rhizobial homology of the pasture species (i.e. Sinorhizobium meliloti for the Medicago species and Rhizobium leguminosarum bv. trifolii for the Trifolium species) had an underlying but major influence on most probable numbers and in determining which rhizobial species occurred more commonly. Estimated populations of rhizobia in soils from homologous legumes were about 8 times those found in soils from non-homologous legumes. The benefits of applying lime to this red-brown earth soil may not have been merely a consequence of correction of low soil pH; increased levels of calcium may also have had a role. The results are discussed in relation to re-establishment of legume leys after the cereal phase of the cropping system.
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Batten, G. D., N. A. Fettell, J. A. Mead, and M. A. Khan. "Effect of sowing date on the uptake and utilisation of phosphorus by wheat (cv. Osprey) grown in central New South Wales." Australian Journal of Experimental Agriculture 39, no. 2 (1999): 161. http://dx.doi.org/10.1071/ea97104.
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Experiments were sown at Cowra and Condobolin to determine the effect of sowing time (April–June) on the response to and utilisation of phosphorus by the wheat cultivar Osprey which requires vernalisation. Crops sown in April needed only 0–2 kg/ha of applied phosphorus to achieve 90% of the maximum yield for the site. This contrasts with crops sown at the traditional sowing time in May–June which needed from 11.5 kg P/ha, on a site with a moderate soil phosphorus status, to 36 kg P/ha, on a site with a very low soil phosphorus status, to produce 90% of the site maximum yield. Crops sown in April had higher yields and even without applied phosphorus accumulated more phosphorus (kg/ha) than crops sown in June with 40 kg P/ha. Crops sown in April had a lower dry matter harvest index, a lower phosphorus harvest index, produced less grain per kilogram of phosphorus in the shoots at maturity, and had a higher grain phosphorus concentration than crops sown in June. Grain protein was not affected by sowing date or the amount of phosphorus applied at sowing. At 90% of maximum dry matter yield shoots had 0.14–0.20% phosphorus at growth stage 30. The critical concentration of phosphorus in grain at 90% maximum grain yield increased with yield from 0.19 to 0.25% phosphorus. Farmers who sow wheat in April can achieve optimum yields with lower inputs of fertiliser phosphorus. However, this benefit will be offset by a lower phosphorus-use efficiency and more rapid depletion of phosphorus reserves from the soil.
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Denney, GD. "Effect of pre-weaning farm environment on adult wool production of Merino sheep." Australian Journal of Experimental Agriculture 30, no. 1 (1990): 17. http://dx.doi.org/10.1071/ea9900017.
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The influence of pre-weaning environment on the adult productivity of medium Peppin Merino sheep has been examined in field experiments. In 1983 and 1984 groups of pregnant ewes and. subsequently, their lambs were run with breeding flocks on farms located over the Central Tablelands and Central Western Slopes of New South Wales. After weaning, each year's progeny grazed as a single flock at Condobolin on the Central Western Slopes, thus allowing the sheep equal nutritional opportunity in post-weaning and adult life. Differences in the progeny's liveweight and wool production could be attributed to the effects of the different environmental conditions experienced before they were weaned. Birth weight and lamb growth rates were affected (P<0.001) by early environment. At weaning, mean group liveweights covered a range of 6.9 kg in 1983 and 7.8 kg in 1984. In both years the proportion of the phenotypic variation of liveweight due to pre-weaning environment fell from approximately 0.35 at weaning to 0.15 (P<0.001) at 12 months of age, but the proportion was not significantly different from zero when the progeny were 24 and 36 months of age. Pre-weaning environment affected the production of greasy wool (P<0.001) over the progeny's first year of life. However, among the 1983 progeny no differences in wool production were observed at 24 and 36 months of age. With 1984 progeny no differences occurred at 24 months of age or, when the wool weights were adjusted to a common liveweight by covariance, at 36 months of age. Yield, fibre diameter and staple length were not affected by pie-weaning environment when measured at 24 and 36 months, and there were no differences between groups in the ratio of secondary to primary wool follicles or in wool follicle density at 36 months of age. It is concluded that the adult productivity of Merino sheep is unlikely to be permanently reduced by poor pre-weaning environmental conditions on farms but overall flock productivity will be reduced if fewer weaners survive.
18
Young, RR, KJ Morthorpe, HI Nicol, and PH Croft. "Effects of sowing time and grazing on the dry matter yield, phenology, seed yield, and hardseed levels of annual pasture legumes in western New South Wales." Australian Journal of Experimental Agriculture 34, no. 2 (1994): 189. http://dx.doi.org/10.1071/ea9940189.
Full textAbstract:
Fifteen annual pasture legumes [Medicago truncatula cvv. Jemalong, Cyprus, Paraggio, Sephi, Parabinga, plus fixed lines SAD 6699, SAD 6766, SAD 7883; M. aculeata lines SAD 2325, SAD 2356; M. scutellata cv. Sava; M. laciniata (cutleaf medic) local ecotype Cl2; Trifolium subterraneum cvv. Nungarin, Dalkeith, Seaton Park] were sown at Condobolin at 6 times in autumn and winter 1986 and periodically grazed at 3 levels of intensity (nil, until flowering, until pod formation). Late sowing greatly reduced (P<0.001) the weight of 50-day-old plants, more so for some varieties (e.g. Cyprus) than others (e.g. Dalkeith, SAD 2325). Seed size accounted for most of the variation (R2 = 0.92) in the weight of plants with 1-2 trifoliate leaves. Total dry matter yields were reduced (P<0.001) by later sowing and grazing, and there were interactions between both of these factors and variety. The subterranean clovers yielded most dry matter and Cyprus and Sava least. Dry matter yields of SAD 6699 and cutleaf medic were reduced least by grazing. Time from sowing until flowering was shorter with later sowing times. With later sowing times, the order of flowering of early-maturing varieties changed, and the difference between the earliest and latest varieties fell from 100 to 11 days. Grazing delayed flowering by up to 2 weeks. All treatments and interactions affected (P<0.001) seed yield. Seed yields were highest (>100 g/m2) in ungrazed early-sown plots and were reduced (P<0.001) at later sowing times by grazing until pod formation for all sowing times for all varieties, and by grazing until flowering for some varieties. Cutleaf medic, Nungarin, and Dalkeith had superior seed yields under adverse conditions of grazing and late sowing. Spring dry matter yields accounted for 90% of the variation in seed yields. There was no optimum dry matter yield for maximum seed yield (except SAD 7883 at 778 g/m2 and cutleaf medic at 275 g/m2) under mild spring conditions, and flowering time did not account for variation (P>0.05) in seed yields at any sowing time. Seeds on previously ungrazed plots progressively softened between 8 December 1986 and 8 March 1987, with those of Jemalong, Cyprus, Parabinga, SAD 6766, cutleaf medic, Dalkeith, and Seaton Park softening more rapidly on later sown plots.
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Rebetzke, G. J., and R. A. Richards. "Genetic improvement of early vigour in wheat." Australian Journal of Agricultural Research 50, no. 3 (1999): 291. http://dx.doi.org/10.1071/a98125.
Full textAbstract:
Grain yield potential of Australian wheat crops is often limited because of inadequate water for crop growth and grain filling. Greater early vigour, defined here as the amount of leaf area produced early in the season, should improve the water-use efficiency and yield of wheat crops grown in Mediterranean-type climates such as occurs in southern Australia. In order to maximise selection efficiency for early vigour in breeding programs, the magnitude and form of genetic variation for early vigour and its components was investigated for 2 contrasting wheat populations. The first population comprised 28 Australian and overseas wheat varieties evaluated in a serial sowing study in Canberra. The second population contained 50 random F 2:4 and F 2:6 families derived from a convergent cross of elite CIMMYT wheat lines evaluated in Canberra, and in the field at Condobolin, New South Wales. For the first population, environmental effects on leaf breadth and length, and to a lesser extent, phyllochron interval, produced significant (P < 0.05) changes in leaf area. Large and significant (P < 0.05) differences were observed among Australian and overseas wheats for early vigour and its components. Australian varieties were among the least vigorous of the lines tested, with a number of overseas varieties producing about 75% greater leaf area than representative Australian wheats. Increased leaf area was genetically correlated with increases in leaf breadth and length, and a longer phyllochron interval. Significant (P < 0.05) genotype ´ environment interaction reduced broad-sense heritability (%) for early vigour (H ± s.e., 87 ± 26) compared with leaf breadth (96 ± 25) and length (97 ± 27). Narrow-sense heritability (%) in the second population was small for leaf area (h2 ± s.e., 30 ± 6) and plant biomass (35 ± 7), but high for leaf breadth (76 ± 14) and length (67 ± 16). Genetic correlations were strong and positive for leaf area with plant biomass, leaf breadth and length, specific leaf area and coleoptile tiller frequency, whereas faster leaf and primary tiller production were negatively correlated with leaf area. The high heritability for leaf breadth coupled with its strong genetic correlation with leaf area (rg = 0.56-0.57) indicated that selection for leaf breadth should produce genetic gain in leaf area similar to selection for leaf area per se. However, the ease with which leaf breadth can be measured indicates that selection for this character either by itself, or in combination with coleoptile tiller production, should provide a rapid and non-destructive screening for early vigour in segregating wheat populations. The availability of genetic variation for early vigour and correlated traits should enable direct or indirect selection for greater leaf area in segregating wheat populations.
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Seddon, Julian, Stuart Doyle, Mark Bourne, Richard Maccallum, and Sue Briggs. "Biodiversity benefits of alley farming with old man saltbush in central western New South Wales." Animal Production Science 49, no. 10 (2009): 860. http://dx.doi.org/10.1071/ea08280.
Full textAbstract:
Agricultural production systems that also provide opportunities to conserve biodiversity will be a crucial component of integrated and sustainable land use in mixed farming landscapes and should be considered and evaluated. Alley farming is an innovative farming system that aims to increase farm profitability while also enhancing environmental outcomes. Alley farming incorporates belts of woody perennial plants such as trees or shrubs, interspersed with alleys of conventionally rotated cropping and livestock grazing land. In the present study, we assessed the impacts on terrestrial biodiversity of alley farming with the native perennial chenopod shrub old man saltbush (Atriplex nummularia Lindl.) in central western New South Wales. Terrestrial biodiversity conservation status was assessed by site surveys conducted in spring 2005, 2006 and 2007 at 15 old man salt bush alley farming sites (OMSB), 15 conventionally managed sites and three native woodland remnants in and around the Condobolin Agricultural Research and Advisory Station in the central western plains of New South Wales. Biodiversity surveys included an assessment of ‘site condition’ – a metric of biodiversity conservation status at the site scale based on measurement of 10 habitat and vegetation condition attributes, compared against benchmark values for the appropriate native ecosystems with relatively little recent anthropogenic modification. Bird surveys were also conducted to assess the diversity and abundance of birds in OMSB, conventional and remnant woodland sites in four functional response groups. Site condition was significantly higher at remnant woodland sites than at conventional farming and OMSB alley farming sites. Remnant woodland sites had greater native overstorey cover and native ground cover of forbs, more trees with hollows, presence of at least some overstorey regeneration and the presence of fallen logs. Site condition was also significantly higher at OMSB sites than at conventional sites and increased significantly across 3 years. By the third year after establishment, OMSB sites had higher native plant species richness and native mid-storey cover than did conventionally farmed sites. These attributes increased markedly over time at the OMSB sites whereas they did not increase at conventional or remnant woodland sites. Native grasses and forbs established under and around the saltbush plants, indicating that OMSB alley plantings can provide habitat for a wide range of native plant species, enhancing biodiversity values of these areas through improved structure and composition. Improved habitat condition at the OMSB sites after 3 years did not lead to a significantly higher diversity or to a higher overall abundance of birds at the OMSB than at conventional sites. Furthermore, diversity and abundance of birds at both OMSB and conventional sites remained significantly below those of remnant woodland sites. Some decliner bird species were observed using OMSB sites, but not conventional sites. Old man saltbush alley farming can provide direct on-site benefits for native biodiversity by improving the structure, function and composition of vegetation at the site or paddock scale. If proposed as a replacement to conventional crop–pasture rotation, OMSB alley farming can enhance biodiversity conservation values, and where production benefits are likely, could play an important role in the integration of production and conservation as a synergistic ‘win–win’ system in mixed farming enterprises.
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Fettell, N. A., C. M. Evans, D. J. Carpenter, and J. Brockwell. "Residual effects from lime application on soil pH, rhizobial population and crop productivity in dryland farming systems of central New South Wales." Australian Journal of Experimental Agriculture 47, no. 5 (2007): 608. http://dx.doi.org/10.1071/ea06070.
Full textAbstract:
A mildly acidic (pHCa 4.79, 0–10 cm depth) red-brown earth soil (Chromosol) at Condobolin in central-western New South Wales was cultivated and limed (once only) at six rates (range 0–4 t/ha) and sown with field peas (Pisum sativumL.) with and without inoculation (once only) with Rhizobium leguminosarum bv. viciae – the rhizobium for peas. The soil already contained a very small population of pea rhizobia (<4 per g soil). The experiment embraced two parallel rotations, each over 4 years: (1) year 1, inoculated peas; year 2, wheat; year 3, wheat; year 4, uninoculated peas; and (2) year 1, inoculated peas; year 2, wheat; year 3, inoculated chickpeas; year 4, uninoculated peas. The objectives of the work were to establish whether liming had any immediate and residual benefits for rhizobia and plants and, if so, to determine if the two events were linked. Liming had an immediate effect on soil pH (0–10 cm depth). Increases in pH were greater per unit of lime at lower rates of application than at higher rates. Although lime effects existed for the duration of the experiment (four seasons of cropping), there was a small decline in soil pH over time (mean decline in unlimed plots 0.16 pHCa units, mean decline in limed plots 0.47 pHCa units). In the first year (pea crop), there was a very large and highly significant response to inoculation on populations of rhizobia in soil and rhizosphere. The number of rhizobia that occurred naturally in uninoculated plots increased rapidly in high-lime plots until, by the third year, they were substantial and, by the fourth year, equal to those in the inoculated treatment. By the end of the experiment, the mean population of rhizobia in the 4 t/ha lime treatment was 7250 per g soil, compared with <4 rhizobia per g in the nil lime treatment. It was noteworthy that, in those years in the rotations when peas were not grown, populations of R. leguminosarum bv. viciae were sustained by their ability to colonise the rhizospheres of wheat and chickpea. In the first pea crop, eight parameters of plant production responded overwhelmingly to inoculation, while there was an underlying response to liming in two of those parameters. The positive effect of inoculation on peas in the first year carried over to the wheat crop of the second year, which was interpreted as a consequence of increased soil N in the inoculated plots. By the third and fourth years, soil populations of pea rhizobia in the plus inoculation and minus inoculation treatments were approximately equal, and inoculation was no longer a determinant of crop production. On the other hand, application of lime, which had only an underlying effect on pea production in the first year, significantly enhanced several parameters of the symbiosis and growth of the chickpea and pea crops, including legume nodulation and percentage nitrogen in the seed. R. leguminosarum bv. viciae, legumes and cereals each responded differently to increasing rates of lime application. Populations of rhizobia in soil and plant rhizospheres increased with each additional rate of liming. Legume productivity responded to additional lime up to 2 t/ha. There was no significant evidence that liming per se had any effect at any time on wheat production. The practical implications of these results are discussed.