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1
Race, D., and A. Curtis. "Adoption of farm forestry in Victoria: linking policy with practice." Australasian Journal of Environmental Management 14, no. 3 (January 2007): 166–78. http://dx.doi.org/10.1080/14486563.2007.10648714.
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2
Slattery, WJ, AM Ridley, and SM Windsor. "Ash alkalinity of animal and plant products." Australian Journal of Experimental Agriculture 31, no. 3 (1991): 321. http://dx.doi.org/10.1071/ea9910321.
Повний текст джерелаАнотація:
The export of farm produce from farming systems results in the removal of excess cations over anions from the soil. This removal of bases from the soil will eventually cause an increase in the acidity of the soil. Ash alkalinity data for a range of farm products are presented in this paper and lime replacement values calculated. Of produce from mixed farming enterprises in north-eastern Victoria, hay required the greatest amount of lime (270-1260 kg CaCO3/ha.year) to replace lost alkali from the soil. By comparison, removal of cereal produce required much less lime (7-20 kg CaCO3/ha.year) to replace lost alkali, as did removal of wool and lamb (0.8 and 6.0 kg CaCO3/ha.year respectively). Management strategies that include a lime replacement value for exported farm produce should be considered in overall farm management strategies to reduce soil acidification.
3
Wales, W. J., J. W. Heard, C. K. M. Ho, C. M. Leddin, C. R. Stockdale, G. P. Walker, and P. T. Doyle. "Profitable feeding of dairy cows on irrigated dairy farms in northern Victoria." Australian Journal of Experimental Agriculture 46, no. 7 (2006): 743. http://dx.doi.org/10.1071/ea05357.
Повний текст джерелаАнотація:
Milk production per cow and per farm in the irrigated region in northern Victoria have increased dramatically over the past 2 decades. However, these increases have involved large increases in inputs, and average productivity gains on farms have been modest. Before the early 1980s, cows were fed predominantly pasture and conserved fodder. There is now large diversity in feeding systems and feed costs comprise 40–65% of total costs on irrigated dairy farms. This diversity in feeding systems has increased the need to understand the nutrient requirements of dairy cows and the unique aspects of nutrient intake and digestion in cows at grazing. Principles of nutrient intake and supply to the grazing dairy cow from the past 15 years’ research in northern Victoria are summarised and gaps in knowledge for making future productivity gains are identified. Moreover, since the majority of the milk produced in south-eastern Australia is used in the manufacture of products for export, dairy companies have increased their interest in value-added dairy products that better meet nutritional requirements or provide health benefits for humans. Finally, some examples of the impacts of farm system changes on operating profit for some case study farms in northern Victoria are presented to illustrate the need for thorough analysis of such management decisions.
4
Graymore, Michelle, Anne Wallis, and Kevin O'Toole. "Understanding drivers and barriers: the key to water use behaviour change." Water Supply 10, no. 5 (December 1, 2010): 679–88. http://dx.doi.org/10.2166/ws.2010.125.
Повний текст джерелаАнотація:
In southwest Victoria, like many other regions in Australia, drought, climate change and population growth have exposed gaps in water supply. To develop effective demand management strategies for rural and regional areas, this paper investigates the drivers and barriers to water saving in southwest Victoria. Although the majority of people felt water saving was important, the drivers for water saving differed between different groups. Residential users were saving water for altruistic reasons, while for farmers the drivers were farm viability and productivity. Although the barriers differed between property types, common barriers included lack of understanding of the impact their water use has on supplies, lack of knowledge, the pricing system and distrust of the water authority. The findings provide information for effective demand management strategies for the region.
5
Rugoho, Innocent, Hayden Lewis, Muhammad Islam, Andrew McAllister, Gemma Heemskerk, Andrew Gourley, and Cameron Gourley. "Quantifying dairy farm nutrient fluxes and balances for improved assessment of environmental performance." Animal Production Science 58, no. 9 (2018): 1656. http://dx.doi.org/10.1071/an16440.
Повний текст джерелаАнотація:
Excess nutrients are challenging the long-term sustainability of grazing-based dairy farming. Whole-farm nutrient-mass balance (NMB) is a well recognised approach to improve on-farm nutrient management decisions. In the present paper, we use a standardised approach for quantifying NMB on grazing-based dairy farms, using a newly developed online tool. Preliminary evaluation, using selected farm data from a previous Australia-wide dairy-farm nutrient study, demonstrated highly comparable estimates of farm area, nutrient fluxes and NMB, with substantial efficiencies in time and sample analysis. Nutrient mass balances were also determined on 16 diverse dairy farms across the five major dairy regions of Victoria, Australia. These results highlighted the importance of purchased feed, fertiliser and milk sales, as major sources of nutrient inputs and outputs, with whole-farm NMB for the 16 dairy farms ranging from 185 to 481 kg/ha for nitrogen, 12–59 kg/ha for phosphorus, 9–244 kg/ha for potassium and –6–55 kg/ha for sulfur. Current industry adoption of the NMB tool has confirmed the benefits of a standardised and efficient collation and processing of readily available farm data to inform nutrient management decisions on commercial dairy farms. We suggest that the standardised assessment of nutrient fluxes, balances and efficiency, as well as feed- and milk-production performance at the whole-farm level, provides dairy farmers, farm advisors and industry and policy analysts with the ability to determine industry-wide goals and improve environmental performance.
6
Young, J. M., A. N. Thompson, M. Curnow, and C. M. Oldham. "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 progeny's survival and lifetime wool production." Animal Production Science 51, no. 9 (2011): 821. http://dx.doi.org/10.1071/an10078.
Повний текст джерелаАнотація:
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 $69 0002 per farm ($14.30/ewe) for south-west Victoria, $51 000 per farm ($8.70/ewe) for Great Southern Western Australia and $33 300 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 $13 000 ($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.
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Zimmer, Heidi C., Jaimie Mavromihalis, Vivienne B. Turner, Claire Moxham, and Canran Liu. "Native grasslands in the PlainsTender incentive scheme: conservation value, management and monitoring." Rangeland Journal 32, no. 2 (2010): 205. http://dx.doi.org/10.1071/rj09073.
Повний текст джерелаАнотація:
The native grassland of the Victorian Volcanic Plain, in south-western Victoria, Australia, is a critically endangered community. Much of the remaining grassland exists on private land, where it is grazed by livestock. The impacts of two grazing management strategies, implemented under the PlainsTender incentive scheme, were monitored at 18 on-farm native grassland sites for 4 years. The management strategies were (1) excluding grazing during spring, or (2) flexible grazing and resting. Maintenance of >70% vegetation cover was required under both strategies. Generalised least-squares (repeated-measures) modelling revealed a significant correlation between plant functional group cover and management. However, this correlation was present at the outset of the study and was maintained for the duration of monitoring. Sites rested from livestock grazing in spring had higher native and exotic grass cover, while exotic forb cover was higher at sites where grazing was managed flexibly. Native and exotic grass cover varied significantly from year-to-year under both management strategies; we attribute this to variation in rainfall, particularly drought in the second year. A key outcome of this study was the recognition that high conservation value native grasslands, i.e. large (≥100 ha) and intact (≥36 native species), are being managed successfully on private land, using a range of conservative livestock grazing strategies.
8
Kabwe, Mwila, Jennifer L. Dittmer, Jaimee Oxford, Catina Eyres, Ancara Thomas, Andrew Mahony, and Bruce Bolam. "A Novel Approach to Managing a COVID-19 Outbreak at a Farm in Outer Regional Victoria, Australia." Nursing Reports 12, no. 4 (October 7, 2022): 717–25. http://dx.doi.org/10.3390/nursrep12040071.
Повний текст джерелаАнотація:
The coronavirus disease (COVID-19) has been established as a major occupational health and safety issue that compounds pre-existing socioeconomic inequalities such as access to basic health services. This is exacerbated in migrant farmworkers who are an essential workforce in maintaining food supply across the country. An outbreak occurred in a remote part of Victoria with limited access to healthcare resources. Existing relationships allowed the Loddon Mallee Public Health Unit to quickly engage farm management and local pathology services and provide cultural and language support. After contact-tracing and comprehensive clinical review, rather than isolate positive cases, those who were asymptomatic and willing to work continued to do so whilst negative workers were in quarantine. Outbreak management and public health actions were quickly implemented even when the nationwide state-testing and contact-tracing systems were experiencing significant strain due to the rapid escalation in case numbers. Despite a large outbreak (68/74 workers), the management of the outbreak allowed asymptomatic cases to perform their work so farm productivity remained uninterrupted. Cases’ health status was closely monitored, with no adverse outcomes in a high-risk population. COVID-19 negative workers safely quarantined away from positive cases until the closure of the outbreak.
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Austen, E. A., P. W. G. Sale, S. G. Clark, and B. Graetz. "A survey of farmers' attitudes, management strategies and use of weather and seasonal climate forecasts for coping with climate variability in the perennial pasture zone of south-east Australia." Australian Journal of Experimental Agriculture 42, no. 2 (2002): 173. http://dx.doi.org/10.1071/ea01030.
Повний текст джерелаАнотація:
A survey of 62 producers in the perennial pasture zone of south-eastern Australia was undertaken to gain an understanding of farmer attitudes toward climate variability, the use of weather and seasonal climate forecasts on farms and how climatic variability affects farm management. The 3 localities surveyed were Hamilton and surrounding districts in south-western Victoria, Lucindale and Naracoorte districts of south-eastern South Australia, and Campbell Town, Ross and Bothwell districts of North Central and upper Derwent Valley regions of Tasmania. Farmers in all districts considered winter rainfall to be the most reliable in terms of consistency, while autumn rainfall was the least reliable but had the greatest impact on production. Perceptions of seasonal rainfall variability and its impact were influenced by stocking rates; farmers with more heavily stocked properties considered rainfall in the growing season to be less reliable than did farmers with lower stocking rates and that autumn and winter rainfall had a greater impact on production. All farmers had strategies to manage their grazing enterprises in response to the prevailing season’s climate conditions, but not all available strategies were used. All participants fed supplements in poorer seasons while Tasmanian farmers tended to reduce stock numbers more in poorer seasons than did Victorian farmers. All the farmers used short-term weather forecasts to help make decisions about farm management, with 100% of farmers in all 3 states using radio and television forecasts and sheep graziers’ warnings. However, farmers felt that many other forecasts were unreliable and they were often were unwilling to incorporate them into decision making. Less than 50% of farmers had read or heard about the 3-month seasonal climate outlook and they were not willing to base management decisions on these outlooks. The uptake of information technology and the use of the Internet amongst farmers in the perennial pasture zone have increased rapidly, with an average of 76% of farmers using a computer and 30% connected to the Internet. Computers were mainly used for financial and farm management, while the Internet was mainly used for farm information. The education level attained by the farmer was the main factor that influenced the uptake and use of information technology.
10
Armstrong, D. P., J. E. Knee, P. T. Doyle, K. E. Pritchard, and O. A. Gyles. "Water-use efficiency on irrigated dairy farms in northern Victoria and southern New South Wales." Australian Journal of Experimental Agriculture 40, no. 5 (2000): 643. http://dx.doi.org/10.1071/ea99132.
Повний текст джерелаАнотація:
A survey of 170 randomly selected, irrigated, dairy farms in northern Victoria and 9 in southern New South Wales was conducted to examine and benchmark the key factors influencing water-use efficiency. Water-use efficiency was defined as the amount of milk (kg milk fat plus protein) produced from pasture per megalitre of water (irrigation plus effective rainfall). Information on water-use, milk production, supplementary feeding, farm size and type, pasture management, and irrigation layout and management was collected for each farm by personal interview for the 1994–95 and 1995–96 seasons. The farms were ranked in the order of water-use efficiency with the average farm compared with the highest and lowest 10% of farms. The range in water-use efficiency was 25–115 kg milk fat plus protein/ML, with the highest 10% averaging 94 kg/ML and the lowest 10% averaging 35 kg/ML. The large range in water-use efficiency indicated potential for substantial improvement on many farms. The high water-use efficiency farms, when compared with the low group: (i) produced a similar amount of milk from less water (387 v. 572 ML) (P<0.05), less land (48 v. 83 ha) (P< 0.05) and a similar number of cows (152 v. 143 cows); (ii) had higher estimated pasture consumption per hectare (11.5 v. 5.5 t DM/ha) (P<0.01) and per megalitre (1.0 v. 0.5 t DM/ML) (P<0.01); (iii) had higher stocking rates (3.2 v. 1.8 cows/ha) (P<0.01); (iv) used higher rates of nitrogen fertiliser (59 v. 18 kg N/ha.year) (P<0.05) and tended to use more phosphorus fertiliser (64 v. 34 kg P/ha.year) (P<0.10); (v) used similar levels of supplementary feed (872 v. 729 kg concentrates/cow); (vi) had higher milk production per cow (396 v. 277 kg fat plus protein) (P<0.05); and (vii) directed a higher proportion of the estimated energy consumed by cows into milk production (53 v. 46%) (P<0.05). The survey data confirmed that irrigated dairy farm systems are complex and variable. For example, the amount of feed brought in from outside the milking area varied from 0 to 74% of the estimated total energy used by a milking herd. There was a large range in the level of supplement input amongst the farms in the high water-use efficiency group, and in the low water-use efficiency group. This indicates that the management of the farming system has a greater impact on the efficiency of water-use on irrigated dairy farms, than the type of system. The data from the survey provide information for individual farms, a measure of the water-use efficiency of the industry, and an indication of the quality of regional land and water resources.
11
Bramley, E., I. J. Lean, W. J. Fulkerson, and N. D. Costa. "Feeding management and feeds on dairy farms in New South Wales and Victoria." Animal Production Science 52, no. 1 (2012): 20. http://dx.doi.org/10.1071/an11214.
Повний текст джерелаАнотація:
Feeding practices in Australian dairy herds were recorded in 100 dairy herds in five districts of two states. A questionnaire about the feeding practices was completed and pasture samples were also collected, where applicable, for analysis. Data and pasture samples were collected once from each farm with visits to regions occurring at different times of the year. Diets were evaluated for nutritional adequacy using the CPM Dairy program. Average milk yield on the day of sampling was 22.8 L/day. The combination of grazed pasture with grain fed during milking was the most prevalent feeding system (54%) in all areas. This was followed by combination of pelleted grain/by-products combined with pasture grazing (25%). Only one herd in the study was not feeding any form of concentrates at the time of sampling. The estimated percentage of concentrate in the diet ranged from 25% ± 11.6 to 44% ± 12.0. Wheat, which was fed at up to 9.8 kg/cow.day DM was the most prevalent grain in all areas, except for Gippsland. The predominant sources of protein in all areas were canola meal, cottonseed meal and lupins. By-products were prevalent, with brewers grain and wheat millrun the most commonly used, fed at 2.8 and 1.6 kg/cow.day DM, respectively. Most farms (81/100) incorporated at least one type of ‘buffer’ in the ration, and limestone (67%) was the most prevalent mineral additive. Monensin and virginiamycin were fed in all areas, with a varying prevalence. Feeding or dose rates used for minerals and rumen modifiers were not always appropriate to those recommended for mineral needs or control of rumen function. This paper demonstrated that a wide variety of feeding systems are used in Australian dairy herds and provides information on nutritive characteristics of pastures.
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Trompf, J. P., and P. W. G. Sale. "The paired-paddock model as an agent for change on grazing properties across south-east Australia." Australian Journal of Experimental Agriculture 40, no. 4 (2000): 547. http://dx.doi.org/10.1071/ea00046.
Повний текст джерелаАнотація:
A detailed study was undertaken on the pasture management practices of 146 producers across south-east Australia who participated in the Grassland’s Productivity Program (GPP) for 3 years between 1993 and 1997. The GPP was an extension program to assist wool producers to develop skills and gain confidence in their ability to manage more productive pastures on their farms. The program consisted of 50 farmer groups (200 farmers participating) spread across the 4 states of South Australia, southern New South Wales, Victoria and Tasmania. Each farmer established paired-paddocks on their own property to compare productive pastures with existing pastures. Productive pastures involve increased rates of fertiliser on pastures containing productive species, with stocking rate adjusted to consume available pasture. After 3 years of involvement in the GPP, there was a whole-farm increase in P fertiliser use by 6.3 kg P/ha, stocking rates by 2.6 dse/ha and annual pasture resowing by 0.9% of the farm, when averaged across the 146 participants. The participants were applying the productive pasture technology to almost a third of their properties in 1997 and the intention was to increase this to over half of their properties by 2000. The participants also changed farm management practices as the program effectively developed management skills. There were increases in the ability to assess pasture quality and quantity, livestock by weighing or physical assessment, and the ability to calculate per hectare production and per hectare gross margins. A high proportion of GPP participants were soil testing (0.92) and spring lambing (0.72) at the completion of the program. The results indicated that the adoption of productive pastures was generally consistent across south-east Australia for pastoral producers who participated in this program, although south-west Victorian and south-east South Australian GPP participants did increase whole-farm P application by more than GPP participants from outside that region. The widespread change in farming practice was attributed to the additive and interactive effect of the paired-paddock comparison, the guidance provided by the facilitator, the group interaction and the skills training. Each of these components of the paired-paddock model combined to form an effective agent for change to increase pasture productivity on these grazing properties.
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Chapman, D. F., B. R. Cullen, I. R. Johnson, and D. Beca. "Interannual variation in pasture growth rate in Australian and New Zealand dairy regions and its consequences for system management." Animal Production Science 49, no. 12 (2009): 1071. http://dx.doi.org/10.1071/an09054.
Повний текст джерелаАнотація:
The profitability of dairy farms in Australia and New Zealand is closely related to the amount of pasture dry matter consumed per hectare per year. There is variability in the pasture growth curve within years (seasonal variation) and between years (interannual variation) in all dairy regions in both countries. Therefore, the biological efficiency of production systems depends on the accuracy and timeliness of the many strategic and tactical decisions that influence the balance between feed supply and demand over an annual cycle. In the case of interannual variation, decisions are made with only limited quantitative information on the range of possible pasture growth outcomes. To address this limitation, we used the biophysical simulation model ‘DairyMod’ to estimate mean monthly herbage accumulation rates of annual or perennial ryegrass-based pastures in 100 years (1907–2006) for five Australian sites (Kyabram in northern Victoria, Terang in south-west Victoria, Ellinbank in Gippsland, Elliott in north-west Tasmania and Vasse in south-west Western Australia) and in 35 years (1972–2006) for three sites in New Zealand (Hamilton in the Waikato, Palmerston North in the Manawatu and Winchmore in Canterbury). The aim was to evaluate whether or not a probabilistic approach to the analysis of pasture growth could provide useful information to support decision making. For the one site where annual ryegrass was simulated, Vasse, the difference between the 25th and 75th percentile years was 20 kg DM/ha.day or less in all months when pasture growth occurred. Irrigation at Kyabram and Winchmore also resulted in a narrow range of growth rates in most months. For non-irrigated sites, the 25th–75th percentile range was narrow (10–15 kg DM/ha.day) from May or June through to September or October, because plant available soil water was adequate to support perennial ryegrass growth, and the main source of interannual variability was variation in temperature. Outside of these months, however, variability in growth was large. There was a positive relationship between total annual herbage accumulation rate and mean stocking for four southern Australian regions (northern Victoria, south-west Victoria, Gippsland and Tasmania), but there was evidence of a negative relationship between the co-efficient of variation in pasture growth and stocking rate. The latter suggests that farmers do account for risk in pasture supply in their stocking rate decisions. However, for the one New Zealand region included in this analysis, Waikato, stocking rate was much higher than would be expected based on the variability in pasture growth, indicating that farmers in this region have well defined decision rules for coping with feed deficits or surpluses. Model predictions such as those presented here are one source of information that can support farm management decision making, but should always be coupled with published data, direct experience, and other relevant information to analyse risk for individual farm businesses.
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Young, J. M., A. N. Thompson, and A. J. Kennedy. "Bioeconomic modelling to identify the relative importance of a range of critical control points for prime lamb production systems in south-west Victoria." Animal Production Science 50, no. 8 (2010): 748. http://dx.doi.org/10.1071/an09103.
Повний текст джерелаАнотація:
Whole-farm decision making is complex as many factors influence the profitability of pasture-based lamb production systems and other influences such as skills and attitudes also affect the behaviours of individual farmers. In this paper we used bioeconomic modelling to identify the relative importance of manipulating components of lamb production systems in south-west Victoria and quantified their likely impacts on whole-farm profitability. Four lamb production systems that varied in relation to the genotype of the ewes and the time of sale of the lambs were examined in the analysis. Two ‘systems’ were based on first-cross Border Leicester × Merino ewes that were mated to a terminal sire and the lambs were either sold as finished slaughter lambs at 45 kg liveweight or as stores at weaning at 30 kg liveweight. The other two ‘systems’ were based on a self-replacing composite breed (Romney × Coopworth base) and the lambs were sold as finished slaughter lambs or stores. Based on the assumptions used the analysis highlighted that the potential economic gain per unit change was high for several factors examined and the relative importance of these critical control points differed between production systems. Matching lamb turn-off (finished or store) to existing ewe genotype improved profitability by more than $100/ha or 50% and optimising pasture utilisation was also important regardless of production system. A 20% increase in pasture utilisation up to the optimum increased whole-farm profit by more than $100/ha. The impacts of improving pasture growth just after the break of season and through early winter on whole-farm profit were even greater. An extra 20 kg of pasture growth per day at this time of the year is potentially worth about $200/ha due to increases in whole-farm stocking rate. Extra pasture growth in early summer also has significant value for later lambing flocks. When farmers have optimised these factors the second-order control points were cost of replacement ewes for the first-cross system, age at first mating and reproduction efficiency in adult ewes. The management and production factors that will provide the greatest return on effort for individual farmers will depend on the potential economic gain per unit change in the target factor, their current management and production levels and the ease with which the management change or increase in production potential can be achieved in the farming system.
15
Norman, CP. "Effect of groundwater pump management on reclaiming salinised land in the Goulburn Valley, Victoria." Australian Journal of Experimental Agriculture 35, no. 2 (1995): 215. http://dx.doi.org/10.1071/ea9950215.
Повний текст джерелаАнотація:
In 1985, groundwater pumping from shallow aquifers, with off-farm disposal, began near Girgarre in the Goulburn Valley, Victoria, to provide salinity control to about 1000 ha of farming land. Two groundwater pumps (TI02 and T103) ran continuously for the first 5 years of the project before reverting to intermittent pumping. The operation of a third pump (T103) was based on the capacity for disposal into an evaporation basin. Following 3 years of groundwater pumping, significant reductions in root-zone (0-0.6 m) soil salinity levels were recorded in both annual and perennial pasture paddocks within 350 m of a pump. Yields of perennial pasture on all monitored paddocks showed a significant increase after commencement of the project. In a paddock 300 m from a groundwater pump, average dry matter production increased from 6.3 to 17.2 t/ha. year within 4 years of pumping. Reclamation was reduced by more than a year on paddocks not subjected to irrigation, or those located >800 m from a groundwater pump. Once reclamation was achieved from continuous pumping, the introduction of intermittent pumping continued to maintain optimum soil salinity and pasture production levels on the irrigated paddocks. However, on a dryland paddock and those located >800 m from a pump, increasing fluctuations in soil salinity and soil sodicity levels were measured under this management regime.
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Heard, J. W., K. R. Lawrence, C. K. M. Ho, and B. Malcolm. "Comparing the profitability of a dairy business with alternative investments." Animal Production Science 57, no. 7 (2017): 1330. http://dx.doi.org/10.1071/an16478.
Повний текст джерелаАнотація:
In the present study, the profitability of a dairy-farm case study evaluated over the period 2003–2004 to 2014–2015 was compared with the performance of other dairy farms and other non-agricultural investments over the same time. Investments are generally made on the expectation that a net return will be earned that justifies using capital in one particular way rather than an alternative way. The expected, and actual, returns from capital invested in different assets will differ according to the risks involved. Investors choose an investment, and mixes of investments, that align with their goals, preferences for risk and anticipated returns over time. Dairy farming involves investing in assets, such as land and improvements, water, livestock, plant and equipment, and people, which are managed to produce milk and ultimately to earn a competitive return on capital. With uncertain seasonal conditions, fluctuating costs and prices, declining terms of trade, wide ranges of equity and management abilities, and a steady decline in the number of commercial farm businesses, it may be tempting to presume that investing in farming, and dairy farming in particular, is a hard road, leading to lower and more variable returns than investing in non-agricultural investment opportunities in the economy. This need not be the case. Analysis of how a dairy business in northern Victoria performed from 2003–2004 to 2014–2015 showed that this farm did well compared with (i) other dairy businesses in Victoria and (ii) alternative investments, such as shares, bonds and property, over the same time. Compound annual return to capital for the dairy farm over the 12 years studied was 12.4% (real, before tax). Over half the return came from the farming operations and the remainder came from owning assets that appreciated in value, particularly in this case, water. The dairy business that was studied was well managed and earned higher annual average returns than the average returns of investments with similar risk elsewhere in the economy, such as shares, and matched it with the best performing of these alternative investments.
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Reid, C. L., and A. M. Ridley. "Environmental motivation and monitoring by landholders in north-east Victoria: fact, fantasy and future implications for catchment management." Australian Journal of Experimental Agriculture 47, no. 3 (2007): 346. http://dx.doi.org/10.1071/ea06021.
Повний текст джерелаАнотація:
This paper reports on the social and business profiles of 39 landholders (in three groups) in north-east Victoria, participating in an Environmental Management Systems (EMS) project, and their motivations for participating in EMS. The level and type of record keeping, formal monitoring, use of electronic technology, and interest or capacity to monitor their environmental performance were also assessed because this is a crucial part of the EMS process and one that research has not reported on to date. Landholder participation in EMS was mostly for reasons of wanting to better account for sustainability issues in farm management. Most participants recorded rainfall, soil test results, production measures and chemical use (in total 69–97%); however, 31% kept no chemical records. Few kept records of remnant native vegetation, pasture management, weeds, pest animals or native fauna. Electronic record keeping systems were used by 26% of participants. Almost all owned a computer and over 70% used the internet and email. To assess interest and capacity to monitor environmental performance, participants were introduced to a water balance calculation tool (this being a locally relevant issue) and asked to calculate their own values. Most participants needed two to three visits to gain confidence to perform the calculations and most did not view the tools as being of much relevance. This was in strong contrast to previous work carried out in the southern Riverina of New South Wales. We conclude that environmental monitoring is more important for catchment management authorities (CMAs) and state agencies than for landholders. If CMAs are to assess how on-farm actions lead to improved environmental performance, there is a need to collect information remotely, invest in monitoring or provide incentives for farmers. There appears to be insufficient record keeping and monitoring by landholders to trace chemical residue problems. This, in addition to a lack of environmental monitoring, means that farmers in north-east Victoria cannot substantiate either ‘clean’ or ‘green’ claims. Future work should focus on awareness and education in natural resource management, as well as improved record keeping and monitoring. Some form of recognition will be needed if the majority of farmers are to participate in environmental programs. Introductory EMS training provides a means of improving business outcomes, documentation and improving environmental management.
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Malerba, Martino E., Nicholas Wright, and Peter I. Macreadie. "A Continental-Scale Assessment of Density, Size, Distribution and Historical Trends of Farm Dams Using Deep Learning Convolutional Neural Networks." Remote Sensing 13, no. 2 (January 18, 2021): 319. http://dx.doi.org/10.3390/rs13020319.
Повний текст джерелаАнотація:
Farm dams are a ubiquitous limnological feature of agricultural landscapes worldwide. While their primary function is to capture and store water, they also have disproportionally large effects on biodiversity and biogeochemical cycling, with important relevance to several Sustainable Development Goals (SDGs). However, the abundance and distribution of farm dams is unknown in most parts of the world. Therefore, we used artificial intelligence and remote sensing data to address this critical global information gap. Specifically, we trained a deep learning convolutional neural network (CNN) on high-definition satellite images to detect farm dams and carry out the first continental-scale assessment on density, distribution and historical trends. We found that in Australia there are 1.765 million farm dams that occupy an area larger than Rhode Island (4678 km2) and store over 20 times more water than Sydney Harbour (10,990 GL). The State of New South Wales recorded the highest number of farm dams (654,983; 37% of the total) and Victoria the highest overall density (1.73 dams km−2). We also estimated that 202,119 farm dams (11.5%) remain omitted from any maps, especially in South Australia, Western Australia and the Northern Territory. Three decades of historical records revealed an ongoing decrease in the construction rate of farm dams, from >3% per annum before 2000, to ~1% after 2000, to <0.05% after 2010—except in the Australian Capital Territory where rates have remained relatively high. We also found systematic trends in construction design: farm dams built in 2015 are on average 50% larger in surface area and contain 66% more water than those built in 1989. To facilitate sharing information on sustainable farm dam management with authorities, scientists, managers and local communities, we developed AusDams.org—a free interactive portal to visualise and generate statistics on the physical, environmental and ecological impacts of farm dams.
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Burkitt, L. L., W. J. Wales, J. W. McDonald, D. R. Small, and M. L. Jenkin. "Comparing irrigated biodynamic and conventionally managed dairy farms. 2. Milk production and composition and animal health." Australian Journal of Experimental Agriculture 47, no. 5 (2007): 489. http://dx.doi.org/10.1071/ea06085.
Повний текст джерелаАнотація:
Ten paired irrigated dairy farms under biodynamic (BD) and conventional (CV) management were compared over a 3-year period (1991–93). The paired farms were located in the irrigation districts of northern Victoria and southern New South Wales and were matched for soil type, cattle breed and farm area. The BD farms practised BD principles for an average of 16 years before the study. The effects of farm management on milk yields and composition and animal health were examined by annually surveying farm managers regarding disease incidence and chemical treatment of animals, and by measuring milk yield and composition and faecal egg counts over the experimental period. The two hypotheses tested were that (1) milk volume and milk solids per cow would be lower under BD management, and (2) the incidence of internal parasitic infection and disease would be lower under CV management. Milk production and milk components produced, both on a per hectare and per cow basis, were 24–36% higher (P < 0.01) under CV management, due to significantly higher pasture intakes (P < 0.001). Although the incidence of parasitic infection was similar for mature cows, CV farms consistently used a greater number of chemical treatments (P < 0.05). Although BD heifer calves <8 months in age had significantly (P < 0.05) higher faecal egg counts, the results highlight the risk of reduced growth rates in calves due to high rates of parasite infection, under both management systems. Somatic cell counts were higher (P < 0.05) under BD management, with this being consistent with the use of significantly less chemical treatments under this management system. The implications of these findings for both CV and BD management for milk production and animal health are discussed.
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Riffkin, Penny A., Paul E. Quigley, Fiona J. Cameron, Mark B. Peoples, and Janice E. Thies. "Annual nitrogen fixation in grazed dairy pastures in south-western Victoria." Australian Journal of Agricultural Research 50, no. 2 (1999): 273. http://dx.doi.org/10.1071/a98034.
Повний текст джерелаАнотація:
Amounts of biologically fixed nitrogen (kg N/ha) were determined in grazed dairy pastures in 3 different areas of south-western Victoria over 12 months between October 1995 and 1996 using measurements of pasture growth, botanical composition, and the 15N natural abundance of white clover (Trifolium repens) and non-legume components. Estimates of the amounts of N fixed, based on N in clover shoots, were similar in each pasture (11, 16, and 18 kg N/ha.year), despite different environmental and management conditions. These on-farm determinations were low compared with experimental studies on N fixation by white clover undertaken in New Zealand (224–291 kg N/ha.year) and elsewhere in Australia (44–135 kg N/ha). Low fixation levels were attributed to low pasture yields (average 8.2 t dry matter (DM)/ha.year) and poor legume content in the swards (average 8%). Despite this, most of the white clover N was derived from atmospheric N2 (65%), and therefore, N fixation could potentially be playing an important role in the N economy of milk production on these farms.
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van der Meulen, A. W., I. J. Reeve, and B. M. Sindel. "Weed management on grazing properties: a survey of livestock producers in New South Wales and Victoria." Australian Journal of Experimental Agriculture 47, no. 12 (2007): 1415. http://dx.doi.org/10.1071/ea06179.
Повний текст джерелаАнотація:
Social research was conducted to explore factors influencing weed management on grazing properties in southern Australia. Face-to-face interviews were held with 122 livestock producers, 94 written questionnaires were returned and 90 grazing properties were visited and rated for weed incidence and management effort. Segmentation techniques revealed three groups, on the basis of farmer demographics and farm characteristics. These groups varied significantly in the range of control methods used, weed management effort, difficulties encountered with weed control and attitudes towards weed control. Respondents were also grouped into four categories with respect to weed control methods: minimal control, mechanical control, grazing control and maximal control. Control groups differed significantly in terms of the number and complexity of methods used, difficulties encountered with weed control, levels of weed awareness and the value placed on various sources of information about weed control. Characteristics of effective weed managers were considered and three factors were identified as underpinning success with weed control. These are referred to as the three ‘Ds’: diligence, diversity and deliberation. These factors have been used to define a three dimensional framework, within which the diversity of approaches towards weed control can be understood.
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McDonald, G. K., E. Tavakkoli, D. Cozzolino, K. Banas, M. Derrien, and P. Rengasamy. "A survey of total and dissolved organic carbon in alkaline soils of southern Australia." Soil Research 55, no. 7 (2017): 617. http://dx.doi.org/10.1071/sr16237.
Повний текст джерелаАнотація:
Dissolved organic carbon (DOC) is important to microbial activity and nutrient cycling, and its concentration is sensitive to pH. Despite the importance of alkaline soils to agricultural production in southern Australia, few studies have documented the concentrations of soil organic carbon (C) and DOC or described the effects of soil properties and management practices on DOC in these soils. A survey of 33 paddocks from the Eyre Peninsula and mid-North regions of South Australia and north-western Victoria demonstrated significant variation in pH, soil organic C and DOC. Carbon stocks in the surface 30cm were 40–55tC/ha and were lowest in paddocks from Victoria. Soils from South Australia had higher DOC concentrations in the top 20cm than soils from Victoria. Principal component analysis suggested variation in DOC was increased by high pH, electric conductivity and the concentration of exchangeable Na, and was reduced by the concentration of exchangeable Ca and clay content. Mid-infrared Fourier transform infrared spectroscopy identified regional differences in the composition of soil organic C, with high amounts of charcoal in Eyre Peninsula soils. Farm management practices had little effect on soil organic C but influenced DOC. Grain yield and DOC concentration were inversely related across and within regions which appeared to be related to the intensity of cropping having opposite influences on yield and DOC. Compared with international data, DOC concentrations were high relative to the amount of soil organic C and, in contrast to many previous studies, DOC in all regions increased with depth.
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Linehan, C. J., D. P. Armstrong, P. T. Doyle, and F. Johnson. "A survey of water use efficiency on irrigated dairy farms in northern Victoria." Australian Journal of Experimental Agriculture 44, no. 2 (2004): 131. http://dx.doi.org/10.1071/ea02234.
Повний текст джерелаАнотація:
Water use efficiency (WUE) in irrigated dairy systems has been defined, in this paper, as the amount of milk (kg milk fat plus protein) produced from pasture per megalitre of water (irrigation plus effective rainfall). A�farm survey was conducted for the 1997–98 and 1998–99 seasons in the Goulburn Irrigation System (GIS) and Murray Irrigation System (MIS) when the irrigation water allocated to irrigators in the GIS was low (100–120% of water right compared with the MIS which was 130 and 200% of water right). These data were analysed in conjunction with information collected on the same farms in the 1994–95 and 1995–96 seasons when the irrigation water allocated to irrigators in both systems was above 150% of water right (Armstrong et al. 1998, 2000). The aim of the survey was to determine if the management decisions made by dairy farmers in seasons of low irrigation water allocations had an impact on WUE.Milk production averaged across the 2 irrigation systems increased significantly over the 5-year period (57 540–75 040 kg milk fat + protein per farm). Over the same period the amount of irrigation water applied (GIS�7.6 ML/ha, MIS 9.2 ML/ha) and the milking area (GIS 72 ha, MIS 73 ha) remained constant. The amount of concentrates fed per cow (GIS 650–1100 kg DM, MIS 480–860 kg DM) and per farm (GIS 119–228 t DM, MIS�72–157 t DM) increased, but pasture consumption (GIS 8.9–9.5 t DM/ha, MIS 9.1–9.7 t DM/ha) did not increase significantly over the survey period. Therefore, the increase in milk production appeared to come primarily from an increase in supplementary feeding rather than an increase in pasture consumption, resulting in no significant change in WUE in either system (GIS 66 kg milk fat + protein/ML, MIS 61 kg milk fat + protein/ML).The survey results indicate that despite varying water allocations in the 2 major irrigation systems in northern Victoria, milk production on farms in both systems increased while changes in WUE could not be detected by the methods used. This suggests tactical options to increase WUE in response to short-term changes in water allocation were either difficult to implement or not a priority in a business sense.
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Hessami, Mir-Akbar, and David R. Bowly. "Economic feasibility and optimisation of an energy storage system for Portland Wind Farm (Victoria, Australia)." Applied Energy 88, no. 8 (August 2011): 2755–63. http://dx.doi.org/10.1016/j.apenergy.2010.12.013.
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Whyte, Merryl, and Suzanne Zyngier. "Applied Intellectual Capital Management." Journal of Intellectual Capital 15, no. 2 (April 8, 2014): 227–48. http://dx.doi.org/10.1108/jic-08-2013-0090.
Повний текст джерелаАнотація:
Purpose – The purpose of this paper is to describe outcomes from a trial of the Danish Intellectual Capital Statement (ICS) within the Australian public sector. Design/methodology/approach – Two work teams within the Department of Primary Industries, Farm Services Victoria (FSV) participated in the trial over a six-month period. Data were collected and triangulated from structured focus groups, researcher guided workshops and individual project record journals kept by participants and observers. Findings – This trial has tested and confirmed existing European Intellectual Capital Management (ICM) theory in a new context, confirmed the strategic management and communication utility of the Danish ICS. It also revealed the utility of this method: to assist the organisation articulate its knowledge-related needs; in developing knowledge management (KM) strategy, in planning and reviewing KM initiatives, in developing clarity and shared context and in navigating change. Research limitations/implications – This research focuses on a single in-depth case study and concurrent organisational restructuring impacted on team focus. Practical implications – The strategic management and communication utility of the Danish ICS was confirmed. The paper demonstrates new insights for practitioners using this ICM method as a useful tool to assist an organisation to articulate KM needs. Originality/value – The primary research gap in the ICM field is examination of the practical application of methods in a real-life context (particularly outside Europe). This work has tested and confirmed existing theory in a new and different context – the Australian public sector.
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Williams, B., J. Walker, and J. Anderson. "Spatial variability of regolith leaching and salinity in relation to Whole Farm Planning." Australian Journal of Experimental Agriculture 46, no. 10 (2006): 1271. http://dx.doi.org/10.1071/ea04110.
Повний текст джерелаАнотація:
An electromagnetic induction (EM31) survey was carried out on a 700-ha property in the western basalt plains of Victoria. The apparent electrical conductivity (ECa) was interpreted in terms of the inferred salt content and, hence, the degree of leaching or recharge through the upper 5 m of the regolith. The focus of the survey was to determine the spatial variability of ECa across a landscape of low relief which included salt lakes. The area mapped is subject to regional groundwater discharge. All parts of the property exhibited hydrological ‘sinks’ and ‘trenches’ of relatively low ECa values, interpreted as areas of preferential recharge or leaching through the regolith. They ranged in size from 200 to 500 m in diameter and/or length and were not related to relief. This apparent hydrological ‘holeyness’ of the upper regolith suggests local recharge into the regional groundwater system. This finding has important implications for Whole Farm Planning and Environmental Management Strategies as local recharge can be reduced by manipulating ground cover and land-use practices. Both the mean and standard deviation of ECa values across the property provide a rational basis for planning land management practices. The location of hydrological ‘holes’ can be built in as significant layers in Whole Farm Plans to minimise water entering the water table and/or salt lakes.
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Burkitt, L. L., D. R. Small, J. W. McDonald, W. J. Wales, and M. L. Jenkin. "Comparing irrigated biodynamic and conventionally managed dairy farms. 1. Soil and pasture properties." Australian Journal of Experimental Agriculture 47, no. 5 (2007): 479. http://dx.doi.org/10.1071/ea05196.
Повний текст джерелаАнотація:
Ten paired irrigated dairy farms under biodynamic (BD) and conventional (CV) management were compared over a 4-year period (1991–94). The paired farms were located in the irrigation districts of northern Victoria and southern New South Wales and were matched for soil type, climate, cattle breed and farm area. Farms had been practising BD principles for an average of 16 years before the commencement of the study and had not received phosphorus (P) fertiliser for an average of 17 years. The effects of farm management on soil chemical and biological properties and the nutritive properties and botanical composition of pasture were examined at varying sampling times during the study. Soil Olsen extractable P concentrations were consistently 2–3 times higher under CV management at various sampling depths (mean = 22 mg/kg, 0–10 cm), and were generally marginal under BD management in the surface 10 cm (mean = 8.5 mg/kg). Low soil extractable P concentrations were also reflected in consistently lower mean pasture P concentrations under BD management (0.25 compared with 0.35% on CV farms). Lower soil and pasture P concentrations under BD management were the result of a large negative P balance across BD farms (–17 kg P/ha.year). A mean negative P balance under BD management was a result of low P imports (2 kg P/ha.year) in comparison with large quantities of P (19 kg P/ha.year) effectively lost from the farming system through animal products, estimated losses in water runoff and slowly reversible soil P reactions. These results suggest that greater P imports are required to ensure the future sustainability of BD dairy pasture farming systems. There were few differences in soil biological properties, with earthworm weights significantly higher under CV management, but no difference in soil organic carbon, humus concentration, the weight of the organic mat or microbial biomass, between the two management systems.
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Campbell, Angus J. D., Annefleur Broekhuizen, Kimbal Curtis, Keith P. Croker, Ralph Behrendt, and Andrew N. Thompson. "A survey of post-weaning mortality of sheep in Australia and its association with farm and management factors." Animal Production Science 54, no. 6 (2014): 783. http://dx.doi.org/10.1071/an13149.
Повний текст джерелаАнотація:
A cross-sectional telephone survey of post-weaning sheep management and mortality was conducted involving 1410 farmers from across Australia. The average reported post-weaning mortality was 4.6%. Mortality was greatest in Queensland and Western Australia, and least in New South Wales, Victoria, and South Australia. Weaner mortality was also greater in the pastoral zone than in the sheep–cereals or high-rainfall zones. Overall, 44% of farms had mortality identified as ‘high’, exceeding the suggested benchmark of ≤4% per annum. High mortality was reported on 50% and 32% of farms with predominantly Merino and crossbred weaners, respectively. There was no statistically significant association between high mortality and the main month of lambing for a flock. Larger sheep flocks, flocks with a smaller proportion of weaners, and farms of smaller area were associated with a greater likelihood of high weaner mortality. The odds of high mortality in weaner flocks that were routinely separated according to bodyweight or condition score was half that of flocks that were managed as one group. Overall, 84% of farmers regularly provided supplementary feed to weaner sheep, but the kind of supplement offered and the proportions of farms routinely supplementing differed between states and sheep production zones. Only high-protein supplementary feeding was associated with lower odds of high mortality. This survey confirms that poor post-weaning survival remains a widespread issue for the Australian sheep industry but identifies farm and management factors associated with reduced weaner mortality.
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Masters, D., N. Edwards, M. Sillence, A. Avery, D. Revell, M. Friend, P. Sanford, G. Saul, C. Beverly, and J. Young. "The role of livestock in the management of dryland salinity." Australian Journal of Experimental Agriculture 46, no. 7 (2006): 733. http://dx.doi.org/10.1071/ea06017.
Повний текст джерелаАнотація:
Management of dryland salinity in Australia will require changes in the design and utilisation of plant systems in agriculture. These changes will provide new opportunities for livestock agriculture. In areas already affected by salt, a range of plants can be grown from high feeding value legumes with moderate salt tolerance through to highly salt tolerant shrubs. A hectare of these plants may support between 500 and 2000 sheep grazing days per year. The type of plants that can be grown and the subsequent animal production potential depend on a range of factors that contribute to the ‘salinity stress index’ of a site, including soil and groundwater salinity, the extent and duration of waterlogging and inundation, the pattern and quantity of annual rainfall, soil texture and chemistry, site topography and other site parameters. Where the salinity stress index is high, plant options will usually include a halophytic shrub that accumulates salt. High salt intakes by grazing ruminants depress feed intake and production. Where high and low salt feeds are available together, ruminants will endeavour to select a diet that optimises the overall feeding value of the ingested diet. In areas that are not yet salt affected but contribute to groundwater recharge, perennial pasture species offer an opportunity for improved water and salt management both on-farm and at the catchments. If perennial pasture systems are to be adopted on a broad scale, they will need to be more profitable than current annual systems. In the high rainfall zones in Victoria and Western Australia, integrated bioeconomic and hydrological modelling indicates that selection of perennial pasture plants to match requirements of a highly productive livestock system significantly improves farm profit and reduces groundwater recharge. In the low to medium rainfall zones, fewer perennial plant options are available. However, studies aiming to use a palette of plant species that collectively provide resilience to the environment while maintaining profitable livestock production may also lead to new options for livestock in the traditional cropping zone.
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Trompf, J. P., D. J. Gordon, R. Behrendt, M. Curnow, L. C. Kildey, and A. N. Thompson. "Participation in Lifetime Ewe Management results in changes in stocking rate, ewe management and reproductive performance on commercial farms." Animal Production Science 51, no. 9 (2011): 866. http://dx.doi.org/10.1071/an10164.
Повний текст джерелаАнотація:
Lifetime Ewe Management is an extension program designed to assist sheep producers to improve their understanding of ewe nutrition and to develop the skills and confidence to improve their management. The course is based on a small-group extension model and was developed by the Lifetimewool project as a way to incorporate the research findings, economic modelling and producer guidelines developed by the project. Lifetime Ewe Management commenced in Victoria in the spring of 2006 and by the end of 2010, 221 producers had completed the 2-year program. The changes in knowledge, attitudes, skills, aspirations and management practices of 182 of these participants were examined. Participants of the Lifetime Ewe Management program increased their whole-farm stocking rates by 14%, increased lamb marking percentages by 11–13% depending on enterprise type, and decreased ewe mortality rates by 43%. These improvements resulted from a significant change in the perceived importance of managing ewes to condition-score targets to improve profitability and increases in the ability of participants to condition score ewes, assess pasture quantity and quality and feed budget. These changes were consistent regardless of how innovative the participants were at the beginning of the program. The appeal and success of the program was attributed largely to the small-group model where producers worked with their own flock under the guidance of a skilled facilitator and with access to effective decision-making tools. The Lifetime Ewe Management program design provides a blueprint for future extension programs striving to achieve widespread practice change.
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Surapaneni, A., and K. A. Olsson. "Sodification under conjunctive water use in the Shepparton Irrigation Region of northern Victoria: a review." Australian Journal of Experimental Agriculture 42, no. 3 (2002): 249. http://dx.doi.org/10.1071/ea00179.
Повний текст джерелаАнотація:
The Shepparton Irrigation Region Land and Water Salinity Management Plan promotes groundwater pumping and re-use for irrigation where groundwater quality and availability allow dilution with channel water (‘conjunctive water use’) to levels that produce minimal production losses from annual and perennial pastures used widely for dairying. In addition, municipal and industrial waste waters are used on a smaller scale for irrigating pastures (and crops). An upper level of irrigation water salinity (expressed as an electrical conductivity of 0.8 dS/m) is currently recommended in the plan. This recommendation is based on empirical data from experiments on unstocked, perennial pasture collected over 2 decades on red-brown earths in the region. While the strategy has, so far, achieved acceptable control of soil salinity levels, while generally maintaining pasture yields, a concern that ‘conjunctive water use’ may not be sustainable in the long term arises from the sodicity of the groundwater and waste waters. The continual addition of sodium to clay soils, initially low in both sodium and electrolytes (upper 0.5 m depth), risks the soils becoming sodified, with attendant soil physical problems should salts be leached to below threshold electrolyte concentrations, as in winter for example. We show that clay soils supporting pastures in the Shepparton Irrigation Region sodify with time under ‘conjunctive water use’. We review evidence for adverse effects of such sodification on soil physical properties affecting plant productivity and hydrologic processes important in the long-term sustainability of the strategy. On-farm management implications of the strategy are discussed and important issues for research are identified.
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Singleton, GR. "Population Dynamics of Mus Musculus and Its Parasites in Mallee Wheatlands in Victoria During and After a Drought." Wildlife Research 12, no. 3 (1985): 437. http://dx.doi.org/10.1071/wr9850437.
Повний текст джерелаАнотація:
The population dynamics and cestodes, nematodes, ticks and fleas of wild mice in mallee wheatlands in Victoria, Australia, were monitored every 6th week from November 1982 to November 1983. Presence of Acarina and Nosopsyllus spp. in a total of 355 mice from farm buildings, crops and near permanent water was independent of that of Hymenolepis fraterna, Taenia taeniaeformis, Aspiculuris tetraptera, Syphacia obvelata and Muspicea borreli. S. obvelata was recorded in every habitat throughout all seasons (although its prevalence was significantly higher in winter near permanent water) and was the most prevalent helminth (67.0%). Overall prevalences of H. fraterna, T. taeniaeformis, A. tetraptera and M. borreli were 7.0, 5.3, 6.2 and 1.7% resp. The overall prevalence of the ticks Radfordia affinis and Myobia murismusculi was 93.9% and that of Nosopsyllus spp. was 36.7%. Other ticks were found on 39.8% of mice. The number of parasite species and prevalence of infection were lowest during severe drought in summer. After the drought parasite prevalence increased significantly . Prevalence of some species differed with habitat, both within and between seasons, but the reasons for the differences were unclear. Prevalence and intensity of parasitism was independent of mouse population density. Muspicea borreli is recorded from Australia for the first time. ADDITIONAL ABSTRACT: The population dynamics and parasite fauna of wild Mus musculus were monitored every 6th week from November 1982 to November 1983 in the mallee wheatlands of northwest Victoria. Endo- and ectoparasites were examined in 355 mice sampled from farm buildings, crops and around permanent water. The presence of ectoparasites (myobiid mites and fleas of the genus Nosopsyllus) was independent of that of endoparasites (nasal mites, cestodes and nematodes). The number of parasite species and prevalence of infection were lowest in summer, a period of severe drought. After the drought, seasonal differences in the number of parasite species were not significant but the prevalence of parasite infection increased significantly. The prevalence and mean intensity of infection varied for each parasite species. The prevalence of many species differed with habitat, both within and between seasons. Generally, reasons for these differences were not clear. The prevalence and intensity of parasitism was independent of mouse population density.
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BOND, K. A., G. VINCENT, C. R. WILKS, L. FRANKLIN, B. SUTTON, J. STENOS, R. COWAN, et al. "One Health approach to controlling a Q fever outbreak on an Australian goat farm." Epidemiology and Infection 144, no. 6 (October 23, 2015): 1129–41. http://dx.doi.org/10.1017/s0950268815002368.
Повний текст джерелаАнотація:
SUMMARYA recent outbreak of Q fever was linked to an intensive goat and sheep dairy farm in Victoria, Australia, 2012-2014. Seventeen employees and one family member were confirmed with Q fever over a 28-month period, including two culture-positive cases. The outbreak investigation and management involved a One Health approach with representation from human, animal, environmental and public health. Seroprevalence in non-pregnant milking goats was 15% [95% confidence interval (CI) 7–27]; active infection was confirmed by positive quantitative PCR on several animal specimens. Genotyping ofCoxiella burnetiiDNA obtained from goat and human specimens was identical by two typing methods. A number of farming practices probably contributed to the outbreak, with similar precipitating factors to the Netherlands outbreak, 2007-2012. Compared to workers in a high-efficiency particulate arrestance (HEPA) filtered factory, administrative staff in an unfiltered adjoining office and those regularly handling goats and kids had 5·49 (95% CI 1·29–23·4) and 5·65 (95% CI 1·09–29·3) times the risk of infection, respectively; suggesting factory workers were protected from windborne spread of organisms. Reduction in the incidence of human cases was achieved through an intensive human vaccination programme plus environmental and biosecurity interventions. Subsequent non-occupational acquisition of Q fever in the spouse of an employee, indicates that infection remains endemic in the goat herd, and remains a challenge to manage without source control.
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Walker, G. P., C. Wijesundera, F. R. Dunshea, and P. T. Doyle. "Seasonal and stage of lactation effects on milk fat composition in northern Victoria." Animal Production Science 53, no. 6 (2013): 560. http://dx.doi.org/10.1071/an11363.
Повний текст джерелаАнотація:
Effect of herd nutrition, time of year and season of calving on milk fat composition and physical properties were examined on irrigated commercial dairy farms in northern Victoria that made use of split-calving and a diverse range of feeding systems. Twenty-four farms were included in the study, and from each farm, morning and evening milk samples were collected from 16 cows that calved in autumn and 16 cows that calved in spring. There were no significant effects of season of calving on the concentration of fatty acids or phospholipids in milk fat, but there were interactions between season of calving and time of year (P < 0.001). These differences could be attributed to changes in energy balance and body condition with stage of lactation. The phospholipids comprising mainly phosphotidylcholine (PC), phosphtidylethanolamine (PE) and sphingomyelin (SP) also varied, with PC and PE being highest in late lactation and SP lowest during peak and mid lactation for both calving groups. Milk fat colour and the concentrations of free fatty acids were more influenced by factors associated with time of year rather than stage of lactation. Milk fat colour in particular showed strong seasonal variation being distinctly lighter in summer–early autumn when compared with rest of the year. Increasing the amount of concentrates fed was associated with decreases in short-chain fatty acid concentration and increases in the solid fat content of milk fat. Variations in nutritional management practices had only small (non-significant) effects on fat composition.
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Wood, M. L., and L. Finger. "Influence of irrigation method on water use and production of perennial pastures in northern Victoria." Australian Journal of Experimental Agriculture 46, no. 12 (2006): 1605. http://dx.doi.org/10.1071/ea05197.
Повний текст джерелаАнотація:
The irrigation of pasture for the dairy industry accounts for a large proportion of Australia’s total irrigation water use, particularly in the Murray–Darling Basin. Most pasture is irrigated using the border-check method. The dairy industry is under increasing pressure to use water more efficiently in response to water market reforms and restrictions on future irrigation water availability, creating interest in the potential of alternative irrigation methods. A field experiment was conducted at Tatura, Victoria, Australia between July 2000 and July 2002 to quantify the differences in water use, perennial pasture production and pasture composition under border-check, surge, sprinkler and subsurface drip irrigation. The experiment aimed to assess each irrigation method as it would perform under farm best management practices. Measurements included applied water, tailwater runoff, soil water status, dry matter production and botanical composition. This experiment found that sprinkler and subsurface drip irrigation used on average 2 ML/ha.year (17–23%) less water than border-check irrigation while maintaining or increasing pasture production, consequently having a significantly higher water use efficiency. Surface runoff was significantly reduced under sprinkler and subsurface drip irrigation. Surge irrigation had no advantages over border-check. Although some differences in pasture composition were observed between irrigation treatments, the trends were inconsistent from one season to the next. The high water use by gravity fed irrigation methods is attributed to a combination of higher evaporation and groundwater accessions.
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Shi, Boyang, Olusegun O. Osunkoya, Aakansha Chadha, Singarayer K. Florentine, and Kunjithapatham Dhileepan. "Biology, Ecology and Management of the Invasive Navua Sedge (Cyperus aromaticus)—A Global Review." Plants 10, no. 9 (September 7, 2021): 1851. http://dx.doi.org/10.3390/plants10091851.
Повний текст джерелаАнотація:
Navua sedge (Cyperus aromaticus (Ridley) Mattf. & Kukenth) is an invasive perennial sedge, native to tropical Africa, which is threatening many natural ecosystems and agroecosystems, especially in northern Queensland, Australia. Crop and pasture production have been impacted by Navua sedge and it is also directly causing reductions in dairy and beef production in affected regions. This review documents the biology, ecology and potential management options to minimise the spread and impact of Navua sedge. The weed reproduces both sexually (seeds) and vegetatively (via underground rhizomes). Its tiny seeds can be spread easily via wind, water, vehicles, farm machinery and animals, whilst the rhizomes assist with establishment of dense stands. The CLIMEX model (which uses distribution and climate data in native and novel ranges) indicates that in Australia, Navua sedge has the potential to spread further within Queensland and into the Northern Territory, New South Wales and Victoria. Several management strategies, including mechanical, chemical and agronomic methods, and their integration will have to be used to minimise agricultural production losses caused by Navua sedge, but most of these methods are currently either ineffective or uneconomical when used alone. Other management approaches, including biological control and mycoherbicides, are currently being explored. We conclude that a better understanding of the interaction of its physiological processes, ecological patterns and genetic diversity across a range of conditions found in the invaded and native habitats will help to contribute to and provide more effective integrated management approaches for Navua sedge.
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Sadras, Víctor, David Roget, and Garry O'Leary. "On-farm assessment of environmental and management constraints to wheat yield and efficiency in the use of rainfall in the Mallee." Australian Journal of Agricultural Research 53, no. 5 (2002): 587. http://dx.doi.org/10.1071/ar01150.
Повний текст джерелаАнотація:
The responses of wheat grain yield to soil properties, weather, root diseases, and management practices were investigated in 75 grower-managed crops in the Mallee region of South Australia, Victoria, and New South Wales during 3 growing seasons. Fourteen cultivars were represented in the sampled crops, with Frame being the most common (56%). The most widespread crop sequence was wheat after pasture (43% of wheat crops), followed by wheat after fallow or cereal (both about 20%); 12% of the wheat was sown after legumes. Wheat after cereal was more common in drier sites, and wheat after fallow in wetter sites. Wheat yield was proportional to Fischer’s photothermal coefficient around flowering, and ranged from nil to 4.7 t/ha. On average, wheat crops sown after cereals yielded 0.4 t/ha less than their counterparts sown after fallow, and 0.7 t/ha less than those after legumes. Sowing date ranged from 24 April to 21 July; yield declined with delayed sowing at an average rate of 17 kg/ha.day. Growing season rainfall (April–October) ranged from 111 to 266 mm, and accounted for 27% of the variation in grain yield. Soil water content at sowing (0–1 m) ranged from 32 to 330 mm; yield increased with initial soil water at an average rate of 6 kg/ha.mm. Grain yield per unit growing season rainfall was generally low, with 75% of crops producing <12 kg grain/ha.mm; the maximum ratio was 21 kg/ha.mm. Soil constraints, including sodicity, alkalinity, salinity, and boron toxicity, reduced yield in part by reducing availability of stored soil water. Owing to severity of chemical constraints increasing with soil depth, grain yield and yield per unit growing season rainfall were both inversely related to the proportion of water stored deeper in the soil (0.5–1 m). Yield was unrelated to nitrogen, both initial and applied. Larger amounts of nitrogen accumulated in soils with more severe constraints partially accounted for the lack of association between yield and nitrogen.
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Young, J. M., R. Behrendt, M. Curnow, C. M. Oldham, and A. N. Thompson. "Economic value of pregnancy scanning and optimum nutritional management of dry, single- and twin-bearing Merino ewes." Animal Production Science 56, no. 4 (2016): 669. http://dx.doi.org/10.1071/an15202.
Повний текст джерелаАнотація:
The nutritional requirements of twin-bearing ewes are ~25% greater than those of ewes with single fetuses during late pregnancy and nearly twice those of non-pregnant ewes. Underfeeding ewes, resulting in liveweight loss during late pregnancy, can have adverse effects on the production and survival of both the lamb and the ewe, and improving twin-lamb survival is critical to improving the overall reproductive performance of the National Merino flock. Scanning for pregnancy status and litter size allows for more precise management of the nutrition of the ewe flock according to the different nutritional needs of dry, single- and twin-bearing ewes. In the present paper, we tested the hypothesis that it is profitable to identify pregnancy status and litter size, and the optimum nutrition profiles are different for dry, single- and twin-bearing ewes. We tested this by examining a range of nutrition strategies for flocks where only the dry ewes were identified, or for flocks where the single- and twin-bearing ewes were identified. A MIDAS model set up for the Hamilton region in south-western Victoria was used for this analysis as it represents the whole flock and it includes a powerful feed-budgeting module that optimises animal and pasture management across the whole farm. The survival and production of the single- and twin-born progeny was adjusted on the basis of the liveweight profile of the single- and twin-bearing ewes. Our hypothesis was supported and profitability was increased by approximately AU$4630/farm or AU$0.80/ewe, by scanning ewes for pregnancy status and litter size, and the optimum liveweight profiles were different for dry, single- and twin-bearing ewes. The majority of the increase in profit was due to identifying litter size and being able to differentially manage the single- and twin-bearing ewes. When ewes are scanned for pregnancy status and litter size, the most profitable combination of profiles involves all ewes losing 4 kg in early pregnancy and single-bearing ewes regaining the 4 kg to lamb at their standard reference weight, twin-bearing ewes gaining 8 kg to lamb above their standard reference weight and dry ewes losing a further 4 kg to be 8 kg lighter than their standard reference weight at lambing time.
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Chapman, D. F., J. Hill, J. Tharmaraj, D. Beca, S. N. Kenny, and J. L. Jacobs. "Increasing home-grown forage consumption and profit in non-irrigated dairy systems. 1. Rationale, systems design and management." Animal Production Science 54, no. 3 (2014): 221. http://dx.doi.org/10.1071/an12295.
Повний текст джерелаАнотація:
The profitability of dairy businesses in southern Australia is closely related to the amount of feed consumed from perennial ryegrass-dominant pasture. Historically, the dairy industry has relied on improvements in pasture productivity and utilisation to support profitable increases in stocking rate and milk production per hectare. However, doubts surround the extent to which the industry can continue to rely on perennial ryegrass technology to provide the necessary productivity improvements required into the future. This paper describes the design and management of a dairy systems experiment at Terang in south-west Victoria (780-mm average annual rainfall) conducted over four lactations (June 2005–March 2009) to compare the production and profitability of two forage base options for non-irrigated dairy farms. These options were represented by two self-contained farmlets each milking 36 mixed-age, autumn-calving Holstein-Friesian cows at peak: (1) well managed perennial ryegrass pasture (‘Ryegrass Max’, or ‘RM’); and (2) perennial ryegrass plus complementary forages (‘CF’) including 15% of farmlet area under double cropping with annual species (winter cereal grown for silage followed by summer brassica for grazing on the same land) and an average of 25% of farmlet area in perennial pasture based on tall fescue for improved late spring–early summer feed supply. The design of these systems was informed by farming systems models (DairyMod, UDDER and Redsky), which were used to estimate the effects of introducing different forage options on farm profitability. The design of the CF system was selected based on modelled profitability increases assuming that all forage components could be managed to optimise forage production and be effectively integrated to optimise milk production per cow. Using the historical ‘average’ pasture growth curve for the Terang district and a mean milk price of $3.71 per kg milk solids, the models estimated that the return on assets of the RM and CF systems would be 9.4 and 15.0%, respectively. The objectives of the experiment described here were to test whether or not such differences in profitability could be achieved in practice, and to determine the risks associated with including complementary forages on a substantial proportion of the effective farm area. Key results of the experiment are presented in subsequent papers.
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Clark, S. G., J. Li, A. M. Johnson, G. N. Ward, and J. F. Chin. "Long-term persistence of subterranean clover Trifolium subterraneum L.) cultivars at three sites in south-western Victoria." Australian Journal of Experimental Agriculture 37, no. 5 (1997): 531. http://dx.doi.org/10.1071/ea97012.
Повний текст джерелаАнотація:
Summary. The seed banks of 6 subterranean clover (Trifolium subterraneum L.) cultivars were sampled at 3 abandoned cultivar evaluation experiments in south-western Victoria (Hamilton, Macarthur and Timboon). Two were var. yanninicum (Trikkala and Larisa) and 4 were var. subterraneum (Denmark, Goulburn, Karridale and Leura). Seed was sampled in late summer–early autumn 1993, between 6 and 10 years after the sites were established and between 3 and 7 years after the sites were abandoned. The collected seed was separated into black and white seed, and a sample of the black seed was grown in a glasshouse and identified as either belonging to the sown cultivar or belonging to another cultivar/genotype. All white seed was assumed to belong to the sown cultivar. The aim was to determine if these widely used cultivars were persisting under farm management conditions and competition from perennial grass, other subterranean clover and annual weeds. With some variation between sites all cultivars were found to be persisting satisfactorily. Over the 3 sites, white-seeded cultivars averaged 460 kg/ha and 6640 seeds/m2; black-seeded cultivars averaged 260 kg/ha and 5590 seeds/m2. Contamination with other subterranean clover cultivars/ecotypes was generally low, except at Macarthur where the white-seeded cultivars were heavily contaminated (Trikkala 39% pure; Larisa 57% pure) with black seeds highlighting the poor adaptation of var. yanninicum to light soil types. Of the black seeds, over the 3 sites, average contamination level was 13% and ranged from 41% (Goulburn at Macarthur) to 1% (Leura at Timboon). The study indicates that in south-western Victoria, all the recently released cultivars are likely to persist and be productive, and that the small-plot evaluation techniques used to identify potential new cultivars are likely to be adequate if replicated in space and if the clovers are sown in mixed swards with perennial grass.
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Zhang, Yuxi, Jeffrey P. Walker, Valentijn R. N. Pauwels, and Yuval Sadeh. "Assimilation of Wheat and Soil States into the APSIM-Wheat Crop Model: A Case Study." Remote Sensing 14, no. 1 (December 24, 2021): 65. http://dx.doi.org/10.3390/rs14010065.
Повний текст джерелаАнотація:
Optimised farm crop productivity requires careful management in response to the spatial and temporal variability of yield. Accordingly, combination of crop simulation models and remote sensing data provides a pathway for providing the spatially variable information needed on current crop status and the expected yield. An ensemble Kalman filter (EnKF) data assimilation framework was developed to assimilate plant and soil observations into a prediction model to improve crop development and yield forecasting. Specifically, this study explored the performance of assimilating state observations into the APSIM-Wheat model using a dataset collected during the 2018/19 wheat season at a farm near Cora Lynn in Victoria, Australia. The assimilated state variables include (1) ground-based measurements of Leaf Area Index (LAI), soil moisture throughout the profile, biomass, and soil nitrate-nitrogen; and (2) remotely sensed observations of LAI and surface soil moisture. In a baseline scenario, an unconstrained (open-loop) simulation greatly underestimated the wheat grain with a relative difference (RD) of −38.3%, while the assimilation constrained simulations using ground-based LAI, ground-based biomass, and remotely sensed LAI were all found to improve the RD, reducing it to −32.7%, −9.4%, and −7.6%, respectively. Further improvements in yield estimation were found when: (1) wheat states were assimilated in phenological stages 4 and 5 (end of juvenile to flowering), (2) plot-specific remotely sensed LAI was used instead of the field average, and (3) wheat phenology was constrained by ground observations. Even when using parameters that were not accurately calibrated or measured, the assimilation of LAI and biomass still provided improved yield estimation over that from an open-loop simulation.
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Bowman, PJ, GM McKeon, and DH White. "An evaluation of the impact of long-range climate forecasting on the physical and financial performance of wool-producing enterprises in Victoria." Australian Journal of Agricultural Research 46, no. 4 (1995): 687. http://dx.doi.org/10.1071/ar9950687.
Повний текст джерелаАнотація:
Improved climate forecasting has the potential to increase the ability of farm managers to cope with a variable climate. In this study a simulation model of a breeding ewe flock was used to make a preliminary assessment of the value of climate forecasting for wool-producing enterprises in Victoria. Stocking and selling policies were modified in response to long-range forecasts of weather conditions. The effects on pasture cover, sheep welfare and financial returns were compared with those of a traditional management policy for a period of 25 years. These comparisons were made at two locations, Hamilton and Rutherglen, and at two stocking rates. The effects of different levels of accuracy of the weather forecast on the value of the changes in stocking and selling policies were also evaluated. Altering the stocking and selling policies using an accurate forecast of seasonal conditions resulted in a reduction in the death rate of adult ewes and their progeny. Timely action when adverse conditions were imminent resulted in an increase in both pasture cover during autumn and winter and minimum liveweight of the sheep. Gross returns were increased on average by more than 5%. Much of this increase was contributed by higher wool returns associated with the increase in size of the flock during favourable conditions. Expenditure on sheep purchases was lower for the traditionally managed farms; however, knowledge of forthcoming conditions did allow stock numbers to be reduced before pasture reserves were depleted in poor seasons which in turn reduced the requirement for supplementary feed. The total cash costs tended to be lower on the traditionally managed farm, but this difference was not significant. Both the cash operating surplus and net cash income were significantly increased by altering stocking and selling policies using an accurate forecast of seasonal conditions at Hamilton, but, although the same trends were evident, the effect of using the forecast at Rutherglen was not significant. Where the forecast was accurate in only 8 years in 10 or 6 years in 10, the benefits of altering the stocking and selling policies were reduced, but even at the lower level of accuracy the average cash operating surplus for the 25 years of the analysis was higher than that achieved using the traditional management regime. However, in individual years, inappropriate policies adopted due to an incorrect forecast resulted in reductions in financial returns of up to 64%. Accurate forecasts can improve land care and animal welfare by changing pasture and animal management, particularly by reducing stock numbers. However, since the profitability of sheep enterprises in Victoria is highly dependent on the choice of stocking rate, recommendations to reduce stock numbers without considering the financial viability of sheep enterprises may go unheeded. Hence, in the short-term at least, it can be difficult to achieve improvements in land care and animal welfare while at the same time maintaining profitability. This study indicated that the financial benefits for wool producers of reliable seasonal outlooks in southern Australia are probably substantially less than generally anticipated, at least for the strategies investigated. Furthermore, the accuracy of seasonal forecasting in southern Australia is such that the benefits from correct forecasts can be partly offset in other years from decisions which have been made on the basis of incorrect forecasts. The study also highlighted a number of important issues that need to be considered in evaluating climate forecasts.
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Biala, J., N. Lovrick, D. Rowlings, and P. Grace. "Greenhouse-gas emissions from stockpiled and composted dairy-manure residues and consideration of associated emission factors." Animal Production Science 56, no. 9 (2016): 1432. http://dx.doi.org/10.1071/an16009.
Повний текст джерелаАнотація:
Emissions from stockpiled pond sludge and yard scrapings were compared with composted dairy-manure residues blended with shredded vegetation residues and chicken litter over a 5-month period at a farm in Victoria (Australia). Results showed that methane emissions occurred primarily during the first 30–60 days of stockpiling and composting, with daily emission rates being highest for stockpiled pond sludge. Cumulated methane (CH4) emissions per tonne wet feedstock were highest for stockpiling of pond sludge (969 g CH4/t), followed by composting (682 g CH4/t) and stockpiling of yard scrapings (120 g CH4/t). Sizeable nitrous oxide (N2O) fluxes were observed only when temperatures inside the compost windrow fell below ~45−50°C. Cumulated N2O emissions were highest for composting (159 g N2O/t), followed by stockpiling of pond sludge (103 g N2O/t) and yard scrapings (45 g N2O/t). Adding chicken litter and lime to dairy-manure residues resulted in a very low carbon-to-nitrogen ratio (13 : 1) of the composting mix, and would have brought about significant N2O losses during composting. These field observations suggested that decisions at composting operations, as in many other businesses, are driven more by practical and economic considerations rather than efforts to minimise greenhouse-gas emissions. Total greenhouse-gas emissions (CH4 + N2O), expressed as CO2-e per tonne wet feedstock, were highest for composting (64.4 kg), followed by those for stockpiling of pond sludge (54.5 kg) and yard scraping (16.3 kg). This meant that emissions for composting and stockpiling of pond sludge exceeded the new Australian default emission factors for ‘waste composting’ (49 kg). This paper proposes to express greenhouse-gas emissions from secondary manure-management systems (e.g. composting) also as emissions per tonne wet feedstock, so as to align them with the approach taken for ‘waste composting’ and to facilitate the development of emission-reduction methodologies for improved manure management at the farm level.
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Saul, Geoffrey, Gavin Kearney, and Dion Borg. "Pasture systems to improve productivity of sheep in south-western Victoria. 1. Growth, composition, nutritive value and persistence of resown pastures." Animal Production Science 49, no. 8 (2009): 654. http://dx.doi.org/10.1071/ea06142.
Повний текст джерелаАнотація:
Two pasture systems were compared at five on-farm sites across south-western Victoria between 1990 and 1996. The ‘typical’ pasture treatment mimicked the pasture and grazing management common in the region, with volunteer annual-based pastures fertilised with around 5 kg/ha phosphorus (P) each year. The ‘upgraded’ pasture treatments were resown to phalaris, perennial ryegrass and subterranean clover, and higher rates of fertiliser (13–25 kg P/ha.year) plus other nutrients were applied. Both pastures were set stocked with the participating farmers breeding ewes. Stocking rate was an emergent variable on each plot. The stocking rate on the typical treatments was based on normal farm practise. Initially, the stocking rate of the upgraded pastures was 15% higher than for the typical pastures and increased over time depending if the ewes in the upgraded pastures were heavier than those in the typical pastures. Measurements included soil fertility, pasture production, nutritive value and composition, and animal production. Net annual pasture production of the upgraded pastures was 10 500 kg/ha compared with 8700 kg/ha for the typical pastures. This average difference (18%) between the treatments was greatly influenced by the large advantage (40%) of the upgraded pasture in the wet year of 1992. Upgraded pastures had higher pasture production than typical pastures in spring but the reverse occurred in autumn. In a separate small plot experiment, the response of each pasture to higher P fertiliser applications was tested. In autumn and winter, there was a significant interaction between pasture type and P rate, with higher responses on the upgraded pastures. In spring, both pastures responded to increased P applications but the upgraded pastures were more responsive at all P rates. The upgraded pastures contained significantly higher legume content (30–50%) than the typical pastures (10–20%). The proportion of sown perennial grasses in the upgraded pasture declined from around 30 to 10% after 6 years displaced by annual grasses and broad-leaf weeds. Herbage from upgraded pastures had significantly higher crude protein content (2–7 units) and digestibility (1–10 units) than the typical pastures with the difference between the treatments increasing over time. The set stocking policy used in this experiment is likely to have exacerbated the decline in sown perennial grasses and implementation of some form of strategic or rotational grazing may have improved persistence. The experiment also highlights the importance of selecting perennial grasses able to cope with the local environment and grazing conditions. Despite the decline in perennials, these results show significant potential to improve pasture productivity and quality in south-western Victoria.
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Ryan, M. H., D. R. Small, and J. E. Ash. "Phosphorus controls the level of colonisation by arbuscular mycorrhizal fungi in conventional and biodynamic irrigated dairy pastures." Australian Journal of Experimental Agriculture 40, no. 5 (2000): 663. http://dx.doi.org/10.1071/ea99005.
Повний текст джерелаАнотація:
The broad-scale factors determining the level of colonisation by arbuscular mycorrhizal fungi in irrigated permanent pasture were investigated using 10 pairs of dairy farms located in northern Victoria, Australia. Each pair consisted of adjacent farms, one under conventional management and the other under biodynamic management. Significant quantities of fertilisers were applied only to the conventional pastures and this was the major difference in inputs between the 2 management systems. Colonisation by arbuscular mycorrhizal fungi of white clover (Trifolium repens L.), perennial ryegrass (Lolium perenne L.) and paspalum (Paspalum dilatatum Poir.) was lower in the conventionally managed pastures than in the biodynamic pastures. On all farms, clover was more highly colonised than the grasses. The level of colonisation in clover exhibited a strong negative relationship with the concentration of phosphorus in the pasture shoots and a weak negative correlation with soil-extractable phosphorus. Similar relationships were evident for the grasses, but these were not as strong. Soil pH, soil organic carbon and the concentration of other soil nutrients (Kjeldahl nitrogen, sulfate, EDTA copper, EDTA zinc, chlorine, and exchangeable potassium, sodium, calcium and magnesium) and pasture shoot nutrients (chlorine, sodium, potassium, calcium, magnesium, manganese, copper, zinc, iron, nitrogen, sulfur and boron) could not account for differences in colonisation levels. On 3 farm pairs, colonisation levels by arbuscular mycorrhizal fungi were monitored over 3.5 years. Colonisation did not vary seasonally. It is concluded that phosphorus levels and host plant will be the major determinants of colonisation levels by arbuscular mycorrhizal fungi in perennial irrigated pasture-based agricultural systems.
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Lawson, A. R., K. B. Kelly, and M. E. Rogers. "Grazing management of dairy pastures based on tall fescue in southern Australia." Crop and Pasture Science 68, no. 12 (2017): 1081. http://dx.doi.org/10.1071/cp16375.
Повний текст джерелаАнотація:
Tall fescue (Festuca arundinacea (Schreb) Darbysh.) has the potential to become a useful component of irrigated dairy pastures in northern Victoria owing to its high dry matter (DM) production compared with perennial ryegrass. However, tall fescue is not widely grown because its grazing management is perceived as difficult. In October 2010, a tall fescue–white clover pasture was established and irrigated. In September 2011, six grazing-management treatments were imposed over 3 years, involving grazing: at 1-leaf stage; at 2-leaf stage (1.5-leaf stage during spring); at 3-leaf stage (2.5-leaf stage during spring); at intervals based upon days between grazings ranging from 15 days in October–December to 60 days in winter; at intervals as above except for 21 days in October–December; and at intervals approximating that of a well-managed perennial-ryegrass-based pasture . Measurements included pre- and post-grazing pasture mass, nutritive characteristics, botanical composition and plant frequency. Pasture consumption from the treatment grazed at the 3-leaf stage was >3.5 t DM ha–1 year–1 (30%) greater than from the three most frequently grazed treatments. However, crude protein content was 1–3% DM units lower when grazed at the 3-leaf stage compared with the two most frequently grazed treatments. There was no effect on estimated metabolisable energy or neutral detergent fibre contents of the pasture on offer. Differences in pasture composition between the pastures grazed at the 3-leaf stage and those most frequently grazed emerged over time and were most conspicuous in the third year, with a greater plant frequency (79% v. 66%) and tall fescue content (61% v. 40% DM) and lower weed content (14% v. 28% DM). From the study, a grazing regime for tall fescue based on the 3-leaf stage appears promising because it produced the most DM over the experiment. A disadvantage of this regime was the need for an extra mowing each year. The practicality of this approach to grazing tall fescue needs to be tested at the whole-farm level.
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Robertson, D., and Q. J. Wang. "Bayesian networks for decision analyses — an application to irrigation system selection." Australian Journal of Experimental Agriculture 44, no. 2 (2004): 145. http://dx.doi.org/10.1071/ea02178.
Повний текст джерелаАнотація:
Farmers are under continual pressure from Government and industry to change farm practices to meet productivity and environmental targets. In response to these pressures, farmers will make decisions to adopt practices that reflect their motivations and priorities. However, where the changes of practice are major, there may be considerable uncertainty associated with the decision-making process. Decision support tools are one method that may assist in reducing the uncertainty associated with decisions about changes in farm practices.Bayesian networks provide a useful tool to assist in the structuring and analysis of decision problems. A Bayesian network is a decision analysis framework, based on Bayesian probability theory, which allows the integration of scientific and experiential knowledge, and the uncertainty associated with this knowledge. The approach involves describing a system in terms of variables and linkages, or relationships between variables, at a level appropriate to the decision making. This is achieved through representing linkages as conditional probability tables and propagating probabilities through the network to give the likelihood of variable outcomes. Therefore, the approach ensures that treatment of risks and uncertainties is an intrinsic part of the decision-making processes. The Bayesian network is dynamic and interactive, and hence if a network previously developed does not fit a user's conceptual understanding of the system, it can be adapted quickly and simply to the cognitive understanding of the user.A case study Bayesian network has been developed for decisions associated with the selection of irrigation systems for irrigated dairy farms in Northern Victoria. This case study demonstrates that the most appropriate irrigation system for a dairy farm is dependent on factors including the amount of irrigation water available and soil types. Analysis of the Bayesian network indicates that the appropriate irrigation system is more sensitive to the income generated from pasture than to the price of water. The Bayesian network can demonstrate the impacts of decisions on the farmer's system and can allow the farmer to evaluate these impacts according to their own priorities and criteria. This information can then be used by the natural resource manager to assess the appropriate level of incentive or penalty required if the farmer is to adopt the preferred option that will also achieve preferable outcomes from a natural resource management perspective.
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Virgona, J. M., A. L. Avery, J. F. Graham, and B. A. Orchard. "Effects of grazing management on phalaris herbage mass and persistence in summer-dry environments." Australian Journal of Experimental Agriculture 40, no. 2 (2000): 171. http://dx.doi.org/10.1071/ea98007.
Повний текст джерелаАнотація:
Grazing management strategies that included resting or intensely utilising pasture on a seasonal basis were compared for their effects on phalaris production and plant frequency (persistence). Experiments were established at 4 on-farm sites (Cootamundra ‘old’, Cootamundra ‘new’, Springhurst and Cavendish) in southern New South Wales and Victoria that had previously been sown to phalaris and were grazed by sheep. At each site, 8 core treatments and extra locally determined treatments were initially imposed in 1993–94 on 2 spatial replicates. In order to determine and describe any year of start effects, treatments were applied again in 1994–95 to plots that had been maintained as controls. The phalaris component of the pastures varied from a minor component to the dominant component depending on site (11–54%). Measurements of botanical composition, available herbage and plant frequency were made between September 1993 and September 1996. Of the core treatments, autumn closure (Cootamundra old and new), winter closure and grazing between defined levels of available herbage (mob stocking) during autumn–winter (Cootamundra old and new, Springhurst), were the most effective in either maintaining or increasing phalaris herbage mass compared to the continually grazed control treatment. In addition, the frequency of phalaris was higher than the control at each of these sites for the autumn–winter mob stocking treatment. These treatments had no effect at the Cavendish site where phalaris was a minor component of the pasture. Rotational grazing, imposed at 2 of the sites (Cavendish and Cootamundra new), led to an increase in phalaris herbage mass compared to continual grazing. A further treatment aimed at encouraging phalaris seedling recruitment by using an extended spring rest until seed fall in summer followed by a rest after the autumn break was imposed at the Cootamundra old site. This treatment increased phalaris herbage mass but did not result in seedling recruitment. The results emphasise the need for periods of rest when buds are regenerating and tillers developing over the autumn–winter period for phalaris pastures in summer-dry environments.
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Trompf, J. P., and P. W. G. Sale. "Differences in management practices and attitudes between the Triple P Program entrants and other pastoral producers in the region." Australian Journal of Experimental Agriculture 41, no. 6 (2001): 773. http://dx.doi.org/10.1071/ea00193.
Повний текст джерелаАнотація:
A survey of the pasture productivity settings, practices and attitudes was undertaken for 229 pastoral producers who volunteered to enter the Triple P Program in 1997, and for 89 pastoral producers from 2 representative districts of Victoria. The latter group of producers was considered to be representative of the general population of pastoral producers in the regions where the Triple P Program was undertaken. Comparison of the survey results reveals that the volunteer participants entering the paired-paddock extension program employed different management practices and had different attitudes to productivity issues compared with the general pastoral producers. Before entering the program the Triple P volunteers were already employing more productive practices such as soil testing, measuring pasture availability and spring lambing. In addition the volunteers had higher whole-farm stocking rates and fertiliser use than the general pastoral producers. The different management practices employed by the 2 groups were consistent with their contrasting attitudes towards managing their farms. The Triple P volunteers were focussed on improving production per hectare through increased stocking rates, which could be achieved by additional expenditure on fertiliser and pasture renovation. The general pastoral producers were more focussed on improving production per head which was achieved by gauging animal performance, maintaining stock in good condition and maintaining expenditure on animal health. We contend that the differences identified between the producers volunteering to participate in the Triple P Program and the general pastoral producers are a direct consequence of the voluntary approach used to recruit Triple P participants. This approach attracts a select group of farmers who are inclined to engage in extension and training activities and tend to have different attitudes and practices to the general pastoral producer. A more proactive approach to recruitment will be required if a larger proportion of the general producer population is to engage in the paired-paddock extension program.
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Celestina, C., P. W. G. Sale, J. R. Hunt, C. Tang, and A. E. Franks. "A single application of fertiliser or manure to a cropping field has limited long-term effects on soil microbial communities." Soil Research 57, no. 3 (2019): 228. http://dx.doi.org/10.1071/sr18215.
Повний текст джерелаАнотація:
A large-scale field experiment was used to investigate the long-term effects of a single application of manure or inorganic fertiliser on microbial communities in the topsoil and subsoil of a cropping field in south-west Victoria. Poultry litter (20 t ha–1) and fertiliser (with equivalent total nutrients to the manure) was either surface broadcast or deep ripped into the subsoil before sowing in 2014. Soil samples were collected from the 0–10 and 25–40cm horizons in each treatment immediately after harvest of the third successive crop in January 2017. Next-generation sequencing of the 16S and ITS rRNA genes was used to characterise the bacterial and fungal communities in the soil. Amendment type and method of placement had a limited effect on soil microbial community structure and diversity, three years after treatments were applied. Fungal communities exhibited weak responses to the poultry litter and fertiliser in comparison to a nil control, but none of the treatments had any detectable effect on bacterial communities. Differences in structure and diversity of microbial communities were overwhelmingly due to their vertical distribution in the soil profile, and not the application of different amendments to the soil by deep ripping or surface broadcasting. The strength and timing of the soil disturbance, plant selection effects and farm management history likely contributed to the lack of measurable response in the soil microbial community.