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Feral pigs and their control with 1080 baiting
No full textFeral pigs are the descendants of domestic pigs (Sus scrofa), which were first brought to Australia by early European colonists. Feral pigs cause a range of agricultural and environmental damage in Western Australia (WA), so control measures are important
Early weaning of lambs in a poor season
No full textThe feed requirements of a ewe with a lamb at foot are higher than if the ewe and lambs are fed separately. In a difficult season with short feed supplies, it is better to early-wean lambs from their mothers to lower feed costs and ensure that the ewes regain condition before joining. This issue becomes even more important as the costs of feeds increase.
Ewe\u27s milk provides the main source of nutrition for lambs until about eight weeks of age. Lambs will sample pasture from about two weeks after birth but by eight weeks of age pasture overtakes milk as the major part of the diet of a lamb. Milk contributes only about 10% of nutrients for the lamb and little nutritional benefit is gained by leaving them with their mothers after this time
Greenhouse gas accounting for Western Australian agriculture 2022
No full textThis report presents new modelling of the greenhouse gas emissions attributable to Western Australia’s agricultural industries and provides an overview of sequestration at the state level. The report improves and expands on the estimates from previous technical reports by the Department of Primary Industries and Regional Development (DPIRD), most notably Curnow et al. (2022). The report presents a new, much broader picture, capturing not only emissions from agricultural activities in Western Australia (WA), but also the emissions associated with the production of agricultural inputs and the sequestration that occurs on agriculturally managed lands. This broader picture of emissions aligns with frameworks for emissions reporting at the business and product level
Decoding the decisive role of seed moisture content in physical dormancy break: filling the missing links
No full textSpecies producing seeds with a water-impermeable seed coat, i.e., physical dormancy (PY), dominate the dry tropical forests. Despite increasing interest and understanding of the germination ecology of a PY species, less is known about how PY break occurs, particularly what changes lead to the opening of the ‘water gap’. Based on the moisture conent (MC) attained, two ranges of PY may exist: shallow PY, a state with higher MC and seeds could reverse to a permeable state when the relative humidity increases; and absolute PY, a completely dry state. Here, we demonstrate that this MC variation between seeds affects preconditioning and the ‘water-gap’ opening stages. A conceptual model developed shows a strong relationship between temperature and duration, with high temperature breaking PY in seconds, but seasonal temperature fluctuations and constant temperatures require a longer time. The duration required at any conditions to break PY is purported to depend on the hydrophobic bonds of the lipids, which are likely weakened during the preconditioning, and the amount of water influences hydrolysis, leading to the ‘water-gap’ opening. We argue that the moisture content of the seeds and its interaction with biochemical compounds are a possible explanation for why only a proportion of PY seeds become permeable to water each year. Nonetheless, empirical investigations must validate these notions
Pasture data reconciliation of the South West Agricultural Zone of Western Australia September 2024
No full textWestern Australia’s (WA) agricultural land use system features extensive pasture land vital for grazing sheep and cattle. Most pastures in the south west of Western Australia consist of annual species that grow during the cool, wet winters of the Mediterranean climate and senesce in the warm to hot, dry summers. Understanding the spatial distribution of pasture areas within the context of mixed farming is essential for developing effective land management strategies to enhance livestock production and profitability through balanced pasture supply and demand.
This report focuses on reconciling pasture area data for the south-west of Western Australia’s agricultural zone across 75 Local Government Areas (LGAs) or shires, spanning from north of Geraldton to Albany and east to Esperance. These pasture areas collectively supported 12.56 million sheep, representing 99% of WA\u27s total sheep flock in 2020-21. The analysis is based on the pasture area data of 2020-21, drawing from multiple sources, including datasets from the Department of Primary Industries and Regional Development (DPIRD), Grains Research and Development Corporation (GRDC), and the Australian Bureau of Statistics (ABS). By excluding grazing areas smaller than 200 hectares and shires associated with hobby farming from the ABS 2020-21 data, the analysis focuses on larger, commercially significant operations, providing a clearer understanding of pasture distribution and land use
The impact of changing joining rates on the Western Australian sheep flock
No full textGiven the poor seasonal conditions and low prices experienced in 2023/24, the Western Australian (WA) sheep industry is experiencing a period of very poor industry sentiment often compared to that seen in the 1990’s following the collapse of the wool reserve price scheme.
These difficult times mean producers have had to make production decisions for their businesses which may have flow on effects for the entire state flock. One commonly discussed option by industry and consultants was to join less ewes to reduce the feed burden on farm and help mitigate losses due to low prices. This computer modelling aimed to investigate the impact of reduced joining rates on the WA flock over three years
Phosphorus buffering determines how soil properties and rainfall influence wheat (Triticum aestivum) yield response to phosphorus fertiliser
No full textContext Current decision support systems (DSS) for phosphorus (P) fertiliser were developed using data from historical cropping systems. An understanding of how soil properties and rainfall influence wheat (Triticum aestivum) response to P fertiliser in current systems is required to optimise P management. Aims The aims of this study were to: (1) assess the soil properties that have the greatest influence on relative yield; (2) examine how rainfall conditions influence relative yield; and (3) examine whether there were interactive effects between rainfall and soil properties on relative yield. Methods Forty P rate-response field experiments were completed in Western Australia. Regression tree modelling, soil test calibration curves and the sliding window approach were used to examine relationships between soil properties or rainfall and relative yield. Key results Phosphorus buffering index (PBI) was important for determining the factors that influence relative yield. For sites with PBI 0–10 cm \u3c56 (n = 30), regression tree modelling showed rainfall before sowing and soil pHCa were important factors (R2 = 0.59). For sites where PBI \u3e56 (n = 10), relative yield was closely related to plant-available P at 0–10 cm and the r-value for the calibration curve was 0.95. Conclusions Rainfall and soil pHCa influence wheat response to P where PBI \u3c56 is attributed to an accumulation of soil P after decades of fertiliser applications and the availability of stored soil P to crops. Implications Pre-sowing rainfall should be included in DSS so that grain producers can make informed, tactical decisions about P fertiliser applications for wheat at sowing
Recommendations for the revision of animal units and their application in the Western Australian rangelands
No full textThis report provides recommendations for the practical application of a methodology for calculating and applying Animal Units in the rangelands of Western Australia.
Animal Units have evolved over time, in their definition, derivation and the size of the standard animals used. This has resulted in their being varying and inconsistent approaches within and across jurisdictions which has limited their application.
The Animal Unit methodology applied in this report is used in other rangeland and pastoral regions, it therefore progresses a nationally consistent approach.
The standard animals used in this methodology are: Animal Equivalent (AE), a 450 kg Bos taurus steer with zero weight gain, walking 7 kilometres per day Dry Sheep Equivalent (DSE); a 45 kg wether with zero liveweight gain, no wool growth beyond that which is included in maintenance and walking 7 kilometres per day.
WA was divided into five Animal Equivalent Rangeland Regions for the purpose of applying Animal Units: Gascoyne-Buffel, Kimberley, Pilbara, Southern Rangeland, Nullarbor.
Available data on diet quality, liveweight and liveweight gain in the beef cattle sector in WA, and insight from the working group formed by DPIRD for this project was used to assign productivity regions to each of the Animal Equivalent Rangeland Regions.
The productivity assigned to regions is based on estimated annual liveweight gain of steers in the regions. The 3 annual productivity levels used are high (annual steer liveweight gain \u3e150 kg), moderate (110-150 kg) and low (\u3c 110 kg).
The assignment of annual productivity of each region were: Gascoyne-Buffel moderate; Kimberley moderate; Pilbara moderate; Southern Rangeland low; Nullarbor moderate.
This report provides recommendations for the Western Australian Government to update Animal Units in line with the annual productivity listed above, including generic AE ratings and intake constant per AE.
The categories of livestock currently used for reporting in the rangelands of WA are very broad. We recommend that the livestock classes used are expanded. The current livestock classes and PCCs can be used as part of the transition to the new methodology.
Existing carrying capacities can be used or adapted with the new approach.
The lack of regionally specific and accurate animal production data has been an impediment in undertaking this work.
There is significant scope for improvements in the application of Animal Units in WA. Additional data on animal growth paths and productivity will refine or confirm the assumed productivity levels.
Updated carrying capacity assessments are required for the Southern Rangelands and Nullarbor regions
Spiny lobster recreational fisheries in Australia and New Zealand: An overview of regulations, monitoring, assessment and management
No full textSpiny (rock) lobsters occur globally and, although harvest is dominated by commercial fisheries, it is important to account for recreational harvest in stock assessments and fisheries management. This paper provides a contemporary review of recreational fishing for five spiny lobster species in Australia and New Zealand. Each jurisdiction has established approaches for collecting data which best meet their information needs (telephone-diary or telephone-recall surveys, charter logbooks, tag reporting). Jurisdictions with specific spiny lobster licences (Western Australia, Tasmania) or mandatory reporting (charter logbooks in Western Australia, tag reporting in Victoria) use these registers as a sampling frame for annual reporting of participation, fishing effort, catch (numbers) and harvest (tonnes). All other jurisdictions use a general fishing licence or general population sampling frame for telephone-diary surveys to provide periodic reporting of catch and harvest. Annual participation in spiny lobster recreational fishing was highest in Western Australia (35,236 ± SE 626 fishers in 2022–23), followed by Tasmania (13,715 ± SE 1067 fishers in 2022–23) and Victoria (5516 fishers in 2020–21). Annual recreational harvest of all spiny lobster species, combined for the most recent data collection period in each jurisdiction, was 830 tonnes; consisting mostly of Western Rock Lobster (Panulirus cygnus) from Western Australia and Southern Rock Lobster (Jasus edwardsii) from Tasmania and New Zealand. This review illustrates the various spatial scales of monitoring, reporting and assessment in each jurisdiction. All monitoring provides information on catch and harvest, with some also reporting participation, effort, carapace length and non-catch related variables. The designs underlying these approaches vary from probability-based (opt-out) and census (mandatory), and it is important to understand the benefits and inherent biases of each. Understanding the parallels between jurisdictions offers valuable insights into how to cost-effectively monitor spiny lobster recreational fisheries and integrate this data into stock assessment and harvest strategies to support sustainable fisheries into the future
Western Australia Pastoral Land Tenure
No full textA map of Western Australia showing the pastoral lease boundaries and names and their tenure.https://library.dpird.wa.gov.au/gis_maps/1014/thumbnail.jp