Bakker D.M.,44 Albany Highway |
Hamilton G.J.,Baron Hay Court |
Hetherington R.,44 Albany Highway |
Spann C.,Mt Barker Research Station
Soil and Tillage Research | Year: 2010
Waterlogging and salinity in the Mediterranean climate of Western Australia (WA) have long been recognized as major constraints to the production of agricultural crops and pastures. While raised beds (RB) prevent waterlogging, the impact of RB on salinity is not known. Their impact on salinity was studied at 3 sites in the Wheatbelt of WA. The salinity dynamics was captured through frequent soil sampling. Two small trials with different mulches were also conducted to investigate possibilities to alter salinity dynamics in other ways.Each of the sites responded differently to the RB. At Cunderdin, being the driest site, little impact of the precipitation on the movement of salt was found, and no difference between the RB and Control. The deeper salinity was found to be more associated with the presence of the shallow saline groundwater. At Woodanilling, a high-rainfall site, salinity changes were governed by precipitation, and the RB greatly reduced waterlogging in the top 10. cm of the soil surface and improved productivity. Little differences were found between RB and Control with respect to salinity due to the incorporation of clayey subsoil. At North Stirlings with medium rainfall, the RB were very effective in reducing waterlogging, improving productivity as well as reducing salinity, following the disruption of the gravelly subsoil layer.Applying a sand mulch made a bare salt scald reasonably productive again. The dry-soil mulch process is also thought to be responsible for the low salt concentrations near the soil surface at Cunderdin. Maintaining the physical properties of this topsoil is crucial for sustaining a productive system.It is also proposed that the salinity-waterlogging interactions are not relevant to the dry-land salinity conditions in WA as the soil surface was either waterlogged or saline but not both at the same time.Our findings have narrowed down the benefits of permanent RB to the waterlogged medium-to-high-rainfall area of WA in regards to waterlogging and loamy gravelly duplex soils in regards to waterlogging and salinity control. As growers in a changing climate (physical and economical) become interested in cropping the waterlogged and saline areas of the valley floors in WA, RB will make that a realistic option. This would equally apply to other parts of the world where waterlogging and salinity are major constraints provided due consideration is given to soil properties of the top soil, particularly the soil texture. © 2010 Elsevier B.V.
Anderson W.K.,44 Albany Highway |
Anderson W.K.,University of Western Australia
Field Crops Research | Year: 2010
Studies that compare the genotypic improvement of historical cultivars with yield progress in commercial crops provide evidence of the impact of past and current research in crops. The analysis of experiments designed to examine combinations of environment (E), management practices (M) and cultivars (G) also provides evidence of the relative importance of each of these factors for yield improvement. The evidence shows that variation due to E far outweighs the variation of grain yield that can be attributed to M or G, or the interactions between these factors, and between these factors and E. The major 'gap' between yields achieved on farms and the theoretical potential as estimated by seasonal rainfall or water use, is found where seasonal water supply is greater than about 250 mm and when management, not rainfall or cultivar is limiting productivity. This suggests that tactical (in season) management, including the choice of crop and cultivar, fertilizer amount and timing, weed, insect and disease control when combined with management of strategic factors (that have an effect for more than one season) such as soil acidity, compaction, low organic matter, non-wetting and water-logging will provide additive benefits that can address the variability imposed by the environment. In the semi-arid cropping regions of the world where inter-seasonal variability of rainfall is high, it is particularly important for farmers to maximize grain yields in seasons when the rainfall is adequate to produce profitable crops. Current technologies are already relatively efficient in the drier seasons so that the relative impact on farm productivity of research to improve yields in dry years is likely to be small. Field studies in Western Australia that have included a range of environments (sites × seasons) cultivars, and levels of management (sowing times, fertilizer treatments, seed rates) show that the main effect of E has accounted for about 80% of the variability in grain yield, M has accounted for about 6%, and G for about 3%. The G × M and G × E interactions were generally unimportant. This is confirmed by studies in similar rainfed environments elsewhere. Some studies that include M as part of the E term show apparently large G × E interactions, possibly due to either the selection of very different cultivars or environments, or both. The usefulness of such results at the farm level is doubtful due to the variable management inputs in the experiments and a lack of validity for farmers who may not be concerned with variability across widely separated locations. In studies that examine genetic responses to individual management practices differences are often very specific to the environmental conditions experienced in the experiments. The aim of the review is to discuss how management factors can contribute to closing the yield 'gap' between actual and potential grain yields in the variable environment experienced by rainfed crops. The impacts of tactical and strategic management practices appear to be independent and additive rather than co-dependent, allowing for adoption one at a time as resources permit. The use of strategic practices that ameliorate acidity or compaction for example, will lift the grain yield at all levels of tactical inputs such as fertilizer, thus reducing the seasonal variability of yield even though the response to fertilizer does not change. It is concluded that in principle, the best way to maintain productivity under conditions of seasonal variability is to use both tactical and strategic management to close the gap between actual and potential grain yields in the average and better seasons. Crown Copyright © 2009.
Whole-farm profit and the optimum maternal liveweight profile of Merino ewe flocks lambing in winter and spring are influenced by the effects of ewe nutrition on the progenys survival and lifetime wool production
Young J.M.,Farming Systems Analysis Service |
Thompson A.N.,Australian Department of Primary Industries and Fisheries |
Thompson A.N.,Murdoch University |
Curnow M.,44 Albany Highway |
Oldham C.M.,44 Albany Highway
Animal Production Science | Year: 2011
Profitability of sheep production systems in southern Australia is optimised at a stocking rate that provides adequate nutrition for breeding ewes and enables efficient utilisation of grown pasture and supplements. In this paper we used bio-economic modelling to develop optimum liveweight1 profiles for spring-lambing Merino ewes in different environments. The modelling included the impacts of the ewe liveweight profile on the production of the ewe and the survival and lifetime wool production of her progeny. Fifteen ewe liveweight profiles were analysed for each region to determine the profitability of varying ewe liveweight at joining, varying rate of loss of liveweight after joining and the rate of gain in liveweight from the minimum to lambing. The analyses support the hypotheses that whole-farm profitability is sensitive to the liveweight profile of Merino ewe flocks and that there is a liveweight profile that maximises whole-farm profit. The variation between the most and least profitable ewe liveweight profile was $690002 per farm ($14.30/ewe) for south-west Victoria, $51000 per farm ($8.70/ewe) for Great Southern Western Australia and $33300 per farm ($9.70/ewe) for southern New South Wales. The changes in profit were due to differences in costs of feeding to achieve the ewe liveweight profile and its influence on the production of both the ewes and their progeny. Failure to include the impacts of liveweight profile on progeny survival and lifetime wool production incorrectly identifies the optimum ewe liveweight profile and provided inaccurate estimates of profitability. The optimum liveweight profiles for ewes lambing in spring were similar for all three regions and insensitive to changing commodity prices, pasture productivity and management. The optimum profile was to join ewes at ∼90% of the standard reference weight of the genotype, lose a small amount of weight after joining and regain weight in late pregnancy to return to the joining weight by lambing. Regaining the liveweight lost in early pregnancy by lambing is the most important target to achieve. The cost per farm of missing this liveweight target by 1 kg was $13000 ($2.60/ewe) for south-west Victoria, $8900 ($1.45/ewe) for Great Southern Western Australia and $5500 ($1.65/ewe) for southern New South Wales. By contrast, the cost per farm of missing the joining target by 1 kg was $5500 for south-west Victoria and less than $2000 across the other two regions. Whole-farm profit increased with increasing stocking rate up to an optimum and regardless of stocking rate there is an additional opportunity to increase whole-farm profit by up to 15% by managing ewes to achieve the optimum liveweight profile. This indicates that the optimum liveweight profile should be achieved by increasing the level of grain feeding and altering the timing of utilising the farm feed resources rather than manipulating stocking rate. © CSIRO 2011.
Van Burgel A.J.,44 Albany Highway |
Oldham C.M.,44 Albany Highway |
Behrendt R.,Australian Department of Primary Industries and Fisheries |
Curnow M.,44 Albany Highway |
And 3 more authors.
Animal Production Science | Year: 2011
The liveweight profile of Merino ewes is related to the production and profitability of the sheep enterprise, but few producers measure liveweight to manage the nutrition of Merino ewes. In this paper we examine the relationship between changes in liveweight and condition score using data from the Lifetimewool project and compare condition score and fat score as alternative monitoring tools. Analyses of liveweight and condition score data from 15 flocks of Merino ewes representing a range of different genotypes and environments showed that the relationship between change in liveweight and condition score was on average 9.2 kg per unit change in condition score or 0.19 times the standard reference weight of the flock. In two experiments experienced operators were used to estimate the condition score and fat score in over 200 ewes and accredited ultrasound scanners measured the eye muscle and fat depth at the C site in the same ewes. All assessments were repeated several times in random order. Within 24 h of the assessments the sheep were slaughtered at local abattoirs where the tissue depth at the GR site was measured on the hot carcasses. Both condition score and fat score were highly repeatable though subject to operator bias. They were related to each other and to the objective measures of fat and eye muscle depth at the C site. However, 95% of sheep below condition score 2.5 had a tissue depth (muscle and fat) at the GR site ≤3 mm, by definition equal to fat score 1. As the condition score of ewes on commercial properties often fluctuates between scores 2 and 3, and small changes in condition score within this range can have large effects on welfare and profit, we conclude that condition score is the most appropriate alternative to liveweight for managing the nutritional profile of ewes. © CSIRO 2011.
Sharma D.L.,75 York Rd |
Anderson W.K.,44 Albany Highway |
Anderson W.K.,University of Western Australia
Agricultural Systems | Year: 2014
Deterioration of crop yields due to exploitive cropping systems (CS) is a worldwide problem reducing profitability for farmers, food availability for consumers and inducing poor utilisation of rainfall. Following a diagnostic approach, likely constraints were identified and corresponding remedies tested in factorial experiments over three years at two sites in the central grain belt of Western Australia. The constraints at the first site (York, sandy clay loam soil) were high cereal cyst nematode (CCN), low cation exchange capacity (CEC) and soil compaction; and the remedies tested were CCN resistant cultivar, green manuring and deep ripping (DR). The constraints at the second site (Beverley, leaching prone sandy duplex soil) were high weed burden (ryegrass, Lolium rigidum L.), soil compaction, low pH and low CEC; and the remedies tested were repeated hay crops, deep ripping including lime application, and green manuring. Nitrogen applications on the cereal crops were split between sowing and after heavy rainfall events at the Beverley site.The crop and variety choice was important at both sites, deep ripping was sometimes useful at Beverley but clearly detrimental at York. CEC was not increased using green manuring. Tactical N showed potential at the leaching site at Beverley where it often assisted in reducing the weed burden. We infer that a diagnostic approach can be successfully used to increase grain yield once constraints have been diagnosed and addressed. Constraints to yield at these sites were related and often interactive implying that addressing only one limiting factor may not be effective in improving yield in the short term. We found that the solution to CS problems can sometimes be as simple as variety replacement (for example, CCN resistant cultivar at York) but can often be complex as seen at the Beverley site.It is concluded that where cropping systems in rainfed areas are not producing yields that approach the limits set by the rainfall, there is a need to devise a system of constraint prioritisation based on yield loss, causal hierarchy and hierarchy of consequences over time. It is suggested that farmers should test the diagnosed remedies on reference paddocks before they commit to heavy costs. Decisions about expensive remedies would ultimately lie in the balance between the costs of lost opportunity and implementation of the remedies. © 2013.
Edirisinghe A.,CSIRO |
Hill M.J.,CSIRO |
Donald G.E.,University of North Dakota |
Hyder M.,44 Albany Highway
International Journal of Remote Sensing | Year: 2011
A knowledge of the amount of pasture biomass available in farm paddocks is crucial for improving utilization and productivity in the Australian grazing industry. A method to quantitatively map the biomass of annual pastures under grazing has been developed using the Normalized Difference Vegetation Index (NDVI) derived from high-resolution satellite imagery. Relationships between fieldmeasured pasture biomass and the NDVI were examined for different transects in paddocks under different grazing regimes across three geographically dispersed farm sites. A significant linear relationship (R2 = 0.84) was observed when the NDVI was regressed against biomass. The slope of the relationship between the NDVI and biomass declined in a highly predictable (R2 = 0.82) exponential form as the growing season progressed and this pattern was consistent across four separate seasons. This knowledge was used to formulate a reliable model to predict paddock average pasture biomass using the NDVI. The model estimates were validated against observed biomass in the range 500-4000 kilograms of dry matter per hectare (kg DM ha-1) with R2 = 0.85 and a standard error of 315 (kg DM ha-1). © 2011 Taylor & Francis.
Cotter J.L.,44 Albany Highway |
van Burgel A.,44 Albany Highway |
Besier R.B.,44 Albany Highway
Veterinary Parasitology | Year: 2015
Anthelminthic resistance in nematodes of beef cattle is an emerging issue globally with implications for effective parasite control. The prevalence of resistance in beef cattle in the Mediterranean-style climatic zone of south-west Western Australia was assessed on 19 farms, using faecal egg count reduction tests. Pre-treatment faecal worm egg counts were compared with counts at 14 days after treatments with ivermectin (injectable), fenbendazole (oral), or levamisole (oral). A separately grazed group treated with topical ivermectin (pour-on) and sampled at 28 days was included as a comparison against injectable ivermectin. The results demonstrate that resistance is common, with failure of at least one anthelmintic (<95% reduction for each species, by arithmetic means) for either of the major species Cooperia oncophora or Ostertagia ostertagi on 17 of the 19 properties. Resistance to ivermectin (injectable) was demonstrated in C. oncophora in 59% of tests, but ivermectin was fully effective against O. ostertagi by this route. Conversely, O. ostertagi resistant to fenbendazole and levamisole were present on 50% and 67% of farms respectively, with both fully effective against C. oncophora. The finding of Haemonchus placei on several properties was unexpected but the egg counts were low and there is no suggestion of pathogenic effects. An indication of reduced efficacy of the pour-on ivermectin formulation compared to the injectable was apparent against both C. oncophora and O. ostertagi, and this may have implications for resistance development, given the widespread use of topical treatments reported in this region. This survey confirms that anthelminthic resistance in nematodes of beef cattle is common in Western Australia and the pattern of occurrence is in general agreement with surveys elsewhere in Australia and in other countries. © 2014 Elsevier B.V.
Brennan R.F.,44 Albany Highway |
Bell M.J.,University of Queensland
Crop and Pasture Science | Year: 2013
The Better Fertiliser Decision for Crops (BFDC) National Database holds historic data for 356 potassium (K) fertiliser rate experiments (431 treatment series) for different rain-fed grain crops and soil types across Australia. Bicarbonate-extractable K (Colwell soil-test K) is the most extensively used soil test reported in the database. Data are available for several crop species grown on a range of soil types from all states except Tasmania. Species represented and number of treatment series in the database are: wheat (Triticum aestivum L.), 254; barley (Hordeum vulgare L.), 5; canola (Brassica napus L.), 130; lupin (Lupinus angustifolius L.), 32; sunflower (Helianthus annuus L.), 10; sorghum (Sorghum bicolor L.), 5; and faba bean (Vicia faba L.), 2. About 77% of the available soil-test K (STK) data on wheat, canola, and lupin are from Western Australia. The usual sampling depth of 0-10cm is recorded for all treatment series within the database, while 68% of experiments have STK information from other soil horizons down the profile, usually in 10-cm increments. The BFDC Interrogator, a comprehensive data search and calibration support tool developed for use with the BFDC National Database, was used to examine STK-yield relationships for each crop across Australia, with more detailed analysis by state/region and then by soil type if data were available. The BFDC Interrogator was used to determine a critical STK concentration to achieve 90% of the maximum relative yield (90%RY) for each crop species, with a critical range (determined by the 70% confidence limit for the 90%RY) also reported. The STK for 90%RY for wheat was 40-41mg/kg on Tenosols and Chromosols, ∼49mg/kg on Kandosols, and ∼64mg/kg on Brown Ferrosols. There was some evidence of critical values increasing with increasing crop yield and on soils with no acidity constraints to root growth, with effects presumably driven by increased crop K demand. The STK for 90%RY for canola, grown mainly on Tenosols, was similar to that for wheat, ranging from 43 to 46mg K/kg, but for lupin, also grown mainly on Tenosols, the STK for 90%RY was a relatively low ∼25mg K/kg. Data for sunflower were limited and the STK for 90%RY was poorly defined. A comparison of critical STK concentrations for different crops grown on Tenosols suggested that critical ranges for 90%RY of lupin (22-27mg K/kg) were significantly lower than that for wheat (32-52mg K/kg) and canola (44-49mg K/kg). Critical STK values were not determined for sorghum and faba bean. © CSIRO 2013.
Beveridge I.,University of Melbourne |
Besier R.B.,44 Albany Highway
Veterinary Parasitology | Year: 2013
As an important producer and exporter of livestock products, animal health has always been of major significance to the Australian economy, and research into efficient parasite control has continued since the 1800s. With substantial research achievements also involving parasites of companion animals and wildlife, Australian parasitologists have made numerous contributions of global significance. This summary outlines the development of investigations into parasite biology and parasitic disease in Australia. © 2013.
Speirs S.D.,Graham Center for Agricultural Innovation |
Reuter D.J.,Reuter and Associates |
Peverill K.I.,K i P Consultancy Services |
Brennan R.F.,44 Albany Highway
Crop and Pasture Science | Year: 2013
Australian grain production depends on applied fertiliser, particularly nitrogen (N) and phosphorus (P), and to a lesser extent potassium (K) and sulfur (S). Despite this dependence, soil testing is used sparingly as a tool to underpin fertiliser decisions. Some grain producers typically conduct soil tests at least once every 3 years on a selection of individual fields, but it is broadly understood that many grain producers use soil testing rarely or not at all. The choice by many grain producers not to support fertiliser decisions by soil testing relates to several factors. One key factor has been a perception that soil test interpretation criteria, previously published separately before collation by K. I. Peverill, L. A. Sparrow, and D. J. Reuter, may be biased or unreliable. The current paper provides an overview of research findings, presented in this special edition of Crop & Pasture Science, describing a national approach to the collation of all available and statistically valid N, P, K, and S response trials for cereal, oilseed, and pulse crops in Australia. It provides an overview of the process adopted to make this single national dataset available to both the grains and fertiliser industries. The process to build adoption has formed an integral component of the approach, as calibration data derived from the national database are being used to underpin soil test interpretation as part of fertiliser recommendations made through Fertcare to grain producers in Australia. © CSIRO 2013.