Graham Center for Agricultural Innovation

Wagga Wagga, Australia

Graham Center for Agricultural Innovation

Wagga Wagga, Australia
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Lim A.,Charles Sturt University | Subhan N.,Graham Center for Agricultural Innovation | Jazayeri J.A.,Graham Center for Agricultural Innovation | John G.,Graham Center for Agricultural Innovation | And 2 more authors.
Phytotherapy Research | Year: 2016

The antimicrobial properties of olive leaf extract (OLE) have been well recognized in the Mediterranean traditional medicine. Few studies have investigated the antimicrobial properties of OLE. In this preliminary study, commercial OLE and its major phenolic secondary metabolites were evaluated in vitro for their antimicrobial activities against Escherichia coli and Staphylococcus aureus, both individually and in combination with ampicillin. Besides luteolin 7-O-glucoside, OLE and its major phenolic secondary metabolites were effective against both bacteria, with more activity on S. aureus. In combination with ampicillin, OLE, caffeic acid, verbascoside and oleuropein showed additive effects. Synergistic interaction was observed between ampicillin and hydroxytyrosol. The phenolic composition of OLE and the stability of olive phenols in assay medium were also investigated. While OLE and its phenolic secondary metabolites may not be potent enough as stand-alone antimicrobials, their abilities to boost the activity of co-administered antibiotics constitute an imperative future research area. Copyright © 2016 John Wiley & Sons, Ltd.


Badgery W.B.,Australian Department of Primary Industries and Fisheries | Millar G.D.,Australian Department of Primary Industries and Fisheries | Broadfoot K.,Australian Department of Primary Industries and Fisheries | Michalk D.L.,Graham Center for Agricultural Innovation | And 3 more authors.
Animal Production Science | Year: 2017

Native pastures account for approximately half the grazing area of the high-rainfall zone of southern Australia and the appropriate intensity of grazing management to improve pasture production and to sustain native species composition is still debated. This paper describes differences in pasture herbage mass, ground cover and composition for a native pasture managed under three distinct grazing-management intensities (1-, 4- and 20-paddock grazing systems). Grazing-management treatments were implemented for 4 years across a variable landscape and the interaction of grazing management and landscape position (high-, medium- and low-production zones) were examined. Increasing the intensity of grazing management (number of paddocks in the grazing system) resulted in higher standing, green and litter herbage mass and ground cover of pastures, with differences most pronounced in the high-production zone where selective grazing was regulated with grazing management. Landscape position largely influenced pasture composition, with higher pasture production and more productive species (e.g. Microlaena stipoides, Lolium rigidum and legumes) in the high-production zone. Small increases in the DM of native perennial grasses and lower levels of legumes and broad-leaf weeds developed in the 20-paddock system compared with grazing in 1- and 4-paddock systems. Net pasture growth was higher in the 20-paddock than 1-paddock treatment during spring in the last 2 years of the experiment, resulting in 21% (1.6 t DM/ha) more herbage mass accumulated over the year. While productivity and cover were higher under intensive rotational grazing, grazing management had little influence on pasture composition. A stable perennial pasture (>70% perennial grasses) stocking rates that were not degrading and the strong influence of landscape on pasture composition limited management influences. Practically, the results indicated that, at the same stocking rate, increasing the intensity of grazing management can increase the average pasture herbage mass, ground cover and pasture growth by more evenly distributing grazing. © CSIRO 2017.


Badgery W.B.,Australian Department of Primary Industries and Fisheries | Mitchell D.,Australian Department of Primary Industries and Fisheries | Millar G.D.,Australian Department of Primary Industries and Fisheries | Broadfoot K.,Australian Department of Primary Industries and Fisheries | And 3 more authors.
Animal Production Science | Year: 2017

Grazing-system experiments address complex interactions among animals, pastures, soils, climate and management. As part of the national EverGraze program, a grazing-system experiment was designed to determine how the intensity of grazing management, from continuous grazing (P01) to flexible 4- and 20-paddock rotational systems (P04 and P20), influences the profitability and sustainability of a Merino ewe, terminal sire, lamb production system grazed on heterogeneous native pastures. When implementing such an experiment, it is important to understand and characterise landscape variability, and include this in the design of the experiment. A second challenge for grazing-system research is to operate experimental systems with sufficient flexibility to adequately represent commercial production systems and maintain even utilisation across treatments. The present paper addresses the following two issues: (1) the process used to characterise the potential productivity of variable native pastures and the results of this characterisation; and (2) the development of flexible systems that adequately represent commercial production within an experiment. This was undertaken with input from a project-steering committee called the EverGraze Regional Group, comprising producers, extension staff and private consultants. Prior to the commencement, the site was mapped into three production zones, namely, high (HPZ), medium (MPZ) and low (LPZ), by visually estimating green herbage mass in late spring and marking boundaries between zones with a GPS. The production zones represented differences in soil properties (gravel, pH and available P) and pasture composition, and were used to balance potential production among plots within the same replication. Grazing-system options were evaluated using the sustainable grazing systems pasture model to help choose an appropriate starting stocking rate. The initial stocking rate chosen for the spring-lambing systems was 5.4 ewes/ha. The modelling predicted large variations in feed availability and quality over summer among years; flexible management criteria were therefore developed, including variable sale time for lambs, to utilise the greater feed supply in better seasons. Minimum-pasture benchmarks (>0.8 t DM/ha standing herbage mass and >80% ground cover) and variable green herbage-mass targets were designed to sustain high levels of livestock production and prevent pasture degradation. Criteria for adjusting ewe numbers were developed, but were constrained to pre-joining (March), scanning (July) and post-weaning (December), being consistent with commercial practices. The experiment incorporated flexible management rules as these were considered integral to the successful management of commercial grazing systems. © CSIRO 2017.


Emebiri L.C.,Graham Center for Agricultural Innovation | Oliver J.R.,Graham Center for Agricultural Innovation | Mrva K.,University of Adelaide | Mares D.,University of Adelaide
Molecular Breeding | Year: 2010

Late maturity α-amylase (LMA) is a genetic defect of wheat which results in the production of α-amylase, shown as substandard falling numbers, in the absence of preharvest rain and under cool temperatures during ripening. The present study is an attempt to use a whole-genome scan with DArT markers to identify chromosomal regions influencing LMA in synthetic hexaploid wheat (SHW). A high heritability estimate of 86.6% was calculated for LMA phenotype measured as optical density in a collection of 91 SHWs. Linkage disequilibrium extended up to 10 cM, and with controls for false positives, significant markers were detected at the chromosome 7B region previously linked to LMA in bread wheat, but not at the chromosome 3B region. Of potentially great interest is a region on chromosome 6B, which was identified as having a significant association with LMA phenotypes in the SHW accessions. Previous investigations suggested existence of an LMA gene on the long arm of 6B, but this is the first time it has been mapped to lie within the centromeric region of chromosome 6B, a region that harbours the Amy-1 genes and whose expression governs activity of the high pI α-amylase isoenzymes. © 2010 Springer Science+Business Media B.V.


Moody P.W.,Science Delivery | Speirs S.D.,Graham Center for Agricultural Innovation | Scott B.J.,Charles Sturt University | Mason S.D.,University of Adelaide
Crop and Pasture Science | Year: 2013

The phosphorus (P) status of 535 surface soils from all states of Australia was assessed using the following soil P tests: Colwell-P (0.5m NaHCO3), Olsen-P (0.5m NaHCO3), BSES-P (0.005m H2SO4), and Mehlich 3-P (0.2m CH3COOH+0.25m NH4NO3+0.015m NH4F+0.013m HNO3+0.001m EDTA). Results were correlated with soil P assays selected to estimate the following: soil solution P concentration (i.e. 0.01m CaCl2 extractable P; Colwell-P/P buffer index); rate of P supply to the soil solution (i.e. P released to FeO-impregnated filter paper); sorbed P (i.e. Colwell-P); mineral P (i.e. fertiliser reaction products and/or soil P minerals estimated as BSES-P minus Colwell-P); the diffusive supply of P (i.e. P diffusing through a thin gel film, DGT-P); and P buffer capacity (i.e. single-point P buffer index corrected for Colwell-P, PBICol). Across all soils, Colwell-P and BSES-P were highly correlated with FeO-P (r≤0.76 and 0.58, respectively). Colwell-P was moderately correlated with mineral P (r≤0.24), but not solution P. Olsen-P and Mehlich-P were both highly correlated with FeO-P (r≤0.80 and 0.78, respectively) but, in contrast to Colwell-P and BSES-P, also showed moderate correlations with soil solution P (r≤0.29 and 0.34, respectively) and diffusive P supply (r≤0.31 and 0.49, respectively). Correlation coefficients with mineral P were r≤0.29 for Olsen-P and r≤0.17 for Mehlich-P. Soils were categorised according to their pH, clay activity ratio, content of mineral P and CaCO3 content, and the relationships between the empirical soil P tests examined for each soil category. Olsen-P and Colwell-P were correlated across all soil categories (r range 0.66-0.90), and a widely applicable linear equation was obtained for converting one soil test to the other. However, the correlations between other soil tests varied markedly between soil categories and it was not possible to develop such widely applicable conversion equations. Multiple step-up linear regressions were used to identify the key soil properties affecting soil solution P, P buffer capacity, and diffusive P supply, respectively. For all soil categories, solution P concentration (measured by CaCl2-P) increased as rate of P supply (measured as FeO-P) increased and P buffer capacity decreased. As an assay of sorbed P, Colwell-P alone did not significantly (P>0.05) explain any of the variability in soil solution P, but when used in the index (Colwell-P/P buffer index), it was highly correlated (r≤0.74) with CaCl2-P. Soil P buffer capacity was dependent on different properties in different soil categories, with 45-65% of the variation in PBI accounted for by various combinations of Mehlich-Al, Mehlich-Fe, total organic C, clay content, clay activity ratio, and CaCO3 content, depending on soil category. The diffusive supply of P was primarily determined by rate of P supply (measured as FeO-P; r range 0.34-0.49), with significant (P<0.05) small improvements due to the inclusion of PBICol and/or clay content, depending on soil category. For these surface soil samples, key properties of pH, clay activity ratio, clay content, and P buffer capacity varied so widely within individual Australian Soil Orders that soil classification was not useful for inferring intrinsic surface soil P properties such as P buffer capacity or the relationships between soil P tests. © CSIRO 2013.


Speirs S.D.,Graham Center for Agricultural Innovation | Scott B.J.,Graham Center for Agricultural Innovation | Moody P.W.,Science Delivery | Mason S.D.,University of Adelaide
Crop and Pasture Science | Year: 2013

The performance of a wide range of soil phosphorus (P) testing methods that included established (Colwell-P, Olsen-P, BSES-P, and CaCl2-P) and more recently introduced methods (DGT-P and Mehlich 3-P) was evaluated on 164 archived soil samples corresponding to P fertiliser response experiments with wheat (Triticum aestivum) conducted in south-eastern Australia between 1968 and 2008. Soil test calibration relationships were developed for relative grain yield v. soil test using (i) all soils, (ii) Calcarosols, and (iii) all 'soils other than Calcarosols'. Colwell-P and DGT-P calibration relationships were also derived for Calcarosols and Vertosols containing measureable CaCO3. The effect of soil P buffer capacity (measured as the single-point P buffer index corrected for Colwell-P, PBICol) on critical Colwell-P values was assessed by segregating field sites based on their PBICol class: very very low (15-35), very low (36-70), low (71-140), and moderate (141-280). All soil P tests, except Mehlich 3-P, showed moderate correlations with relative grain yield (R-value ≥0.43, P<0.001) and DGT-P exhibited the largest R-value (0.55). Where soil test calibrations were derived for Calcarosols, Colwell-P had the smallest R-value (0.36), whereas DGT-P had an R-value of 0.66. For 'soils other than Calcarosols', R-values >0.45 decreased in the order: DGT-P (r≤0.55), Colwell-P (r≤0.49), CaCl2-P (r≤0.48), and BSES-P (r≤0.46). These results support the potential of DGT-P as a predictive soil P test, but indicate that Mehlich 3-P has little predictive use in these soils. Colwell-P had tighter critical confidence intervals than any other soil test for all calibrations except for soils classified as Calcarosols. Critical Colwell-P values, and confidence intervals, for the very very low, very low, and low P buffer capacity categories were within the range of other published data that indicate critical Colwell-P value increases as PBICol increases. Colwell-P is the current benchmark soil P test used in Australia and for the field trials in this study. With the exception of Calcarosols, no alternative soil P testing method was shown to provide a statistically superior prediction of response by wheat. Although having slightly lower R-values (i.e. <0.1 difference) for some calibration relationships, Colwell-P yielded tighter confidence intervals than did any of the other soil tests. The apparent advantage of DGT-P over Colwell-P on soils classified as Calcarosols was not due to the effects of calcium carbonate content of the analysed surface soils. © CSIRO 2013.


Packer E.L.,Charles Sturt University | Clayton E.H.,Australian Department of Primary Industries and Fisheries | Clayton E.H.,Graham Center for Agricultural Innovation | Cusack P.M.V.,Australian Livestock Production Services
Australian Veterinary Journal | Year: 2011

Objective To determine the prevalence of subacute rumen acidosis (SARA) in beef cattle grazing lush pasture and the effect of monensin on reducing SARA and improving animal performance. Design Commercial Angus and Murray Grey steers received a monensin slow-release capsule (n = 19) or remained untreated (n = 19). Cattle grazed an oats crop or tetraploid ryegrass pasture for a total of 91 days. Rumen fluid pH, volatile fatty acids (VFA) and lactic acid concentrations and body weight data were collected prior to treatment and again 28, 56 and 91 days after treatment. Changes in measures over time were analysed using mixed model repeated measures analysis. Differences in average daily gain between treatment groups were determined. Results The prevalence of SARA was low during the study, with only one animal satisfying criteria for SARA at one time point. Cattle treated with monensin capsules were 11.9kg heavier at the completion of the study compared with untreated controls (414.5 ± 3.88kg vs 402.6 ± 4.03kg, P = 0.04). Rumen VFA and L- and D-lactate levels did not differ between cattle treated with monensin and untreated cattle. However, the ratio of propionate to acetate plus two times butyrate was higher (P < 0.001) when cattle were treated with monensin. Conclusions Subacute rumen acidosis was not consistently detected under the conditions of the study. The higher body weight of cattle treated with monensin may have been due to improved energy utilisation of the pasture, indicated by increased propionate proportions in the rumen, rather than prevention of SARA. © 2011 The Authors. Australian Veterinary Journal © 2011 Australian Veterinary Association.


Watmuff G.,Geographic Web Solutions Pty Ltd | Reuter D.J.,Reuter and Associates Pty Ltd | Speirs S.D.,Graham Center for Agricultural Innovation
Crop and Pasture Science | Year: 2013

During the past 50 years, 3800 field experiments yielding over 5200 treatment series were conducted in Australia examining yield responses to applied N, P, K, or S fertiliser applications to cereal, oilseed and pulse crops. The experiments all had accompanying soil test data. These data were entered into multiple Microsoft Access® database templates and then consolidated into a single national online MYSQL® database. A web application (named the BFDC Interrogator) was also developed to rapidly access the national database (BFDC National Database) and construct soil test calibrations between percentage of the maximum grain yield achieved (hereafter called percentage relative yield) and soil test values recorded for specified ranges of regional or national experiments. Search parameters were applied to define soil test calibrations. These included farming system (dryland or irrigated), year of experiment, soil type, crop type, soil test, depth of soil sampling and soil test units. Other data filters based on site metadata, such as method of nutrient placement, can be applied to enable more definitive calibrations. The calibrations are used to derive critical soil test values at 80, 90 and 95% relative crop yield with 95% confidence limits. However, the soil test criteria at 90% relative crop yield with 70% confidence limits have been chosen as the single calibration and reliability standard for all crops and soil tests. Corresponding yield increase (t/ha)-soil test relationships for an applied nutrient can also be accessed. The BFDC National Database and BFDC Interrogator can now be accessed online by trained, registered users. This paper describes the methodologies that underpinned the progressive development of this tool. Through the commitment of the grains and fertiliser industries, it is anticipated that the calibrations will be used to improve decision support systems used to generate fertiliser recommendations for Australian cropping industries. © CSIRO 2013.


Orchard P.W.,Graham Center for Agricultural Innovation | Hackney B.,Graham Center for Agricultural Innovation
Landscape Ecology | Year: 2016

Context: This short communication responds to calls for greater input from agronomists into landscape research as a means of contributing to managing the positive and negative effects of farming systems. This was recognised in New South Wales, Australia in relation to the management of soil acidity in landscapes of variable topography. Objective: The response was the development of a structured course (Landscan) aimed at educating land managers to match land use with landscape capability. The course characteristics are briefly presented in terms of reading, measuring and interpreting landscape features, understanding degradation processes, assessing available management tools and prioritising actions to balance production, profit and sustainability. Method: The main features of the course content and mode of delivery are detailed including evaluation of participants in regards to increased knowledge, skills and potential changes in practice. Results: Over 1000 land managers have completed the course with most indicating that they will alter priorities, change strategies and adjust goals as a result and 97 % indicated they would recommend the workshops to others. The Landscan framework also provides a means for researchers to incorporate their results for rapid uptake as well as identifying research gaps. The course has been used to deliver integrated group outcomes in areas of soil health, biodiversity, water quality and weed management. Conclusion: The framework addresses the issue of greater involvement of agronomists in landscape research and has successfully initiated dialogue with other disciplines. While the emphasis to date has been on livestock production in variable landscapes the model should be applicable in other farming systems. © 2015, Springer Science+Business Media Dordrecht.


Dowling C.W.,Back Paddock Company P L | Speirs S.D.,Graham Center for Agricultural Innovation
Crop and Pasture Science | Year: 2013

Scientists readily suggest that research and development is not complete until findings and conclusions are reported in the peer-reviewed literature. The authors suggest that industry-specific relevant research and development is actually not complete until the key outputs are extended to primary stakeholder groups. In the case of 'Making Better Fertiliser Decisions for Cropping Systems in Australia' (BFDC), this meant training key members of the grains and fertiliser industries, where nitrogen, phosphorus, potassium, and sulfur recommendations are derived from soil tests and provided to farmers. The BFDC project applied a two-part cascading approach to extension and training to reach the grains and fertiliser industries. The train-the-trainer program (Level 1) was undertaken and targeted at influential and experience persons such as technical leaders and those who influenced crop-nutrition decision support systems (DSS) within interested organisations. Level 2 activities targeted individuals within organisations who had direct discussion with farmers about soil testing, and their training was facilitated by a Level 1 trained colleague. Development of extension plans, training course structure, and training resources was conducted in parallel with the development of the BFDC National Database and BFDC Interrogator from the commencement of the project. In so doing, it was agreed that controlled access to the information should be established to maintain a consistent standard of use and to provide a platform for gathering feedback to guide future developments (e.g. of the BFDC Interrogator or prioritising future experimental investment). The BFDC extension approach targeted 100 individuals from the Level 1 audience and 30 individuals from the Level 2 audience through seven train-the-trainer level workshops conducted across Australia. As a result of reaching this audience, it was expected that the cumulative effect of the cascading extension strategy and input of BFDC Interrogator critical nutrient concentrations in commercial soil analysis interpretation software would indirectly and directly influence the crop nutrient management decisions of up to 5000 Australian grain farmers in the year after the commencement of training activities. Exit survey results, conducted as part of the BFDC train-the-trainer workshops, were aggregated across all Level 1 workshops. These survey results showed that the most significant benefit of the training was the usefulness of the BFDC Interrogator training manual and the additional teaching aids supplied. The importance and significance to the industry of the collation of data through BFDC was also highlighted as a benefit. Reflecting industry knowledge gaps (e.g. crop×nutrient×geographic region interactions), the lowest ranking survey results focused on the ability of the BFDC National Database to provide usable critical soil test criteria for several situations. Yet despite this reported shortcoming, participants recognised the significance of the structure, tools, skills, and knowledge gained through the training workshop and the importance of the established critical levels. While face-to-face training enables robust discussion, the 'time-poor' nature of roles for agricultural professionals appeared to limit the uptake of training opportunities. Therefore, training materials are being developed into an online course focused particularly on university requirements and the development of agricultural professionals. © CSIRO 2013.

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