Victorian Mallee Research Articles

Predation event and shelter site use by a threatened monitor lizard, Varanus rosenbergi, in the Little Desert, Victoria

AbstractHeath monitors (Varanus rosenbergi) are arguably the most thoroughly studied Australian varanid, largely stemming from long‐term research on Kangaroo Island, South Australia. However, research on other populations within this species' disjunct distribution is limited. We opportunistically tracked a heath monitor in the Little Desert National Park, Victoria, after it consumed a painted dragon (Ctenophorus pictus) which we were radiotracking for another study. We report the first record of a heath monitor depredating a painted dragon, as well as the first record of heath monitors repeatedly using a hollow log for shelter. The hollow log was occupied on 10 consecutive occasions over 18 days, and then again on five occasions 9–11 months later. Our observations identify hollow logs as a habitat resource which should be considered in conservation strategies for this threatened monitor lizard. Furthermore, we observed two individuals in close proximity, possibly a breeding pair, in January. This implies that breeding may occur in summer for the Victorian mallee population, as has been reported in other populations, rather than in spring as has been speculated. Research is sorely needed across this species' disjunct distribution across southern Australia. To date, populations of heath monitors in the Victorian mallee have garnered no scientific study, despite their listing as Critically Endangered.

Recognizing the Mallee

Drawing on fieldwork in the Victorian Mallee region of Australia, this article explores the ways in which reading groups can elicit rich information about the relationship between literature, reading, and place. The study found that book group participants “recognized” the Mallee in the texts under discussion and engaged in their own forms of place knowledge and “history‑telling” in response, making corrections to, and even rejecting, literary representations of their area. We argue that the resources for enhancing literary infrastructure exist, both in the broad history and diversity of Mallee writing, and in the social infrastructure of the Mallee. Readers’ knowledge, captured through book‑related discussion in community spaces, offers the potential for enhancing existing literary resources in rural and remote regions.

Non-destructive measurement of canopy cover is an alternative to biomass sampling at anthesis to predict yield of canola-quality Brassica juncea

Biomass at anthesis is an important trait in predicting yield of Brassica oilseeds in environments where seed filling occurs in dry and warm conditions. This study aimed to compare the ability of non-destructive canopy cover measurements (Sunfleck ceptometer and digital photography) with direct biomass sampling at anthesis to predict the yield of canola-quality B. juncea (juncea canola) hybrids. Field experiments were conducted in the Victorian Mallee (226-248 mm annual rainfall) and the Wimmera (266-407 mm annual rainfall) regions from 2012 to 2014. Nineteen juncea canola genotypes were sown in the first year and 10 to 11 genotypes in the subsequent two years of field experiments. The experimental plots were laid out in a randomized complete block design with three replications. Days to 50% flowering, canopy cover and biomass at 50% flowering and seed yield were recorded. The study concluded that at low rainfall sites (<250 mm annual rainfall), the canopy cover measurements had consistent and significant positive relationships with biomass at anthesis (r 2 =0.43-0.61 in 2012 and r 2 =0.72 in 2013) and seed yield (r 2 =0.25-0.41 in 2012 and r 2 =0.51 in 2013). Canopy cover also showed a positive and significant relationship with early flowering (r 2 =0.52 in 2012 and r 2 =0.60 in 2013) at the relatively low rainfall site. These results suggest that non-destructive canopy cover measurement could replace direct biomass sampling at anthesis in prediction of yield of juncea canola hybrids in low rainfall environments.

Howling Wilderness and Promised Land: Imagining the Victorian Mallee, 1840–1914

This article traces the changing understandings and representations of the Victorian Mallee region in the years 1840–1914. It tracks the multiple ways in which the region was imagined and discussed, paying close attention to how these imaginings were both shaped by and in turn themselves shaped the landscape. We argue that while the Mallee experience became emblematic of the broader Australian struggle with the land and thus the founding narrative of the pioneer legend, the Mallee as a distinct region retained local, specific meanings, including the idea of a preferred English settler. We identify the Federation Drought as a turning point in ecological, national and cultural understandings of the region.

Mass to height relationships in annual pastures and prediction of sheep growth rates

The relationship between pasture height and mass influences the availability of pasture for grazing, and is important for predicting intake of pasture and liveweight change by sheep. The relationship between pasture mass and structure and sheep production is poorly defined for low-mass, clumpy pastures in low-rainfall regions. Between 2001 and 2004, 480 quadrats of pastures were measured in 23 paddocks throughout the Victorian Mallee. Pasture height was related to live mass for medic (linear; r2 = 0.70; P &lt; 0.001) and grassy medic (asymptotic; r2 = 0.64; P &lt; 0.001) pastures, and prediction of grassy medic pasture height was improved by inclusion of proportion live groundcover. During 2004, pasture dry matter accumulation and liveweight changes in sheep grazing annual pastures were measured and compared with predicted outputs from GrazFeed, a software model used to estimate feed intake and liveweight change in sheep. Improved predictions of liveweight gain in grazing sheep were obtained using measured height rather than the GrazFeed default height. The results show that the height to mass relationship of annual pastures in the Victorian Mallee differs between pasture types, between years, and may differ from other published relationships. This study provides information that may assist in the development of models of grazing systems.

Minds in the Cave: Insects as Metaphors for Place and Loss

The practice-led PhD art research project 'Gathering Shadows' investigates the visual poetics of a speculative ‘ecological gaze’ at a time of ecological crisis. The project considers two environments but avers from the distancing objectification characteristic of lens-based capture and the tired genre of ‘landscape’. Instead, it proposes a symbolic order in which imagery of native invertebrates are presented as indices of the generic non-human 'Other'. This is conveyed with reflections on deep time, ecological sited-ness, ecological continuities and, most importantly, ecological disruption. Employing a unique analogic plein air technique for recording diminutive live subjects without a camera, the research pivots upon a trio of ecomimetic cues: first, its deeply indexical processes reveal an insect umwelten of uncanny intimacy and semiotic presence. Second, it is a process in which images tend to be facilitated not predetermined, where results are partially outcomes of chance-driven, counter-anthropocentric interactions between artist and environment. Third, rather than evoke traditional use of chiaroscuro the artworks present an inverted world of x-ray-like shadows—an oblique and somber metaphor appropriate to the 'dark' ecological conditions the project confronts. The project responds to two sites: semi-arid Lake Tyrrell in the Victorian Mallee, and the sub-alpine plateau of Mount Buffalo. Lake Tyrrell once informed a sacred reciprocity of sky with country in indigenous culture. The loss of this reciprocity is memorialised by using raw starlight falling on the lakebed to contact-print fresh photographic films with the imagery of relics of insect fauna gathered from the lakeshore. In the Australian Alps (the subject of this paper) the project focuses on the keystone species Bogong Moth Agrotis Infusa. These iconic invertebrates, and the imminent decline of their ecosystem due to climate change, inform the exquisitely detailed digital enlargements derived from cameraless images of swarming moths gathered from a summit cave.

Enduring Drought Then Coping With Climate Change: Lived Experience And Local Resolve In Rural Mental Health

Climate change awareness has taken a dramatic turn in Australia, intensifying debate over the meaning of prolonged drought for rural futures, with critical implications for rural mental health. This paper is drawn from research on perceptions of Australian climate during a period of marked shift in public awareness of climate change (2004–2007). It utilises oral histories gathered in dryland farm communities of the semiarid Victorian Mallee at the edge of the nation’s commercial cropping zone – in particular, the stories of women’s health workers – to highlight the interdependency of environmental, economic, political and mental health concerns in rural and remote communities. Focusing on lived experience, the paper explores the narratives through which people have apprehended drought and climate change – in discourse of endurance, uncertainty and putative adaptation – revealing advocacy and local resolve in the provision of rural mental health services, and, fundamentally, a paradigm of embodiment in rural social work.

Advances in precision agriculture in south-eastern Australia. III. Interactions between soil properties and water use help explain spatial variability of crop production in the Victorian Mallee

A major barrier to the adoption of precision agriculture in dryland cropping systems is our current inability to reliably predict spatial patterns of grain yield for future crops for a specific paddock. An experiment was undertaken to develop a better understanding of how edaphic and climatic factors interact to influence the spatial variation in the growth, water use, and grain yield of different crops in a single paddock so as to improve predictions of the likely spatial pattern of grain yields in future crops. Changes in a range of crop and soil properties were monitored over 3 consecutive seasons (barley in 2005 and 2007 and lentils in 2006) in the southern section of a 167-ha paddock in the Mallee region of Victoria, which had been classified into 3 different yield (low, moderate, and high) and seasonal variability (stable and variable) zones using normalised difference vegetation index (NDVI) and historic yield maps. The different management zones reflected marked differences in a range of soil properties including both texture in the topsoil and potential chemical-physical constraints in the subsoil (SSCs) to root growth and water use. Dry matter production, grain yield, and quality differed significantly between the yield zones but the relative difference between zones was reduced when supplementary irrigation was applied to barley in 2005, suggesting that some other factor, e.g. nitrogen (N), may have become limiting in that year. There was a strong relationship between crop growth and the use of soil water and nitrate across the management zones, with most water use by the crop occurring in the pre-anthesis/flowering period, but the nature of this relationship appeared to vary with year and/or crop type. In 2006, lentil yield was strongly related to crop establishment, which varied with soil texture and differences in plant-available water. In 2007 the presence of soil water following a good break to the season permitted root growth into the subsoil where there was evidence that SSCs may have adversely affected crop growth. Because of potential residual effects of one crop on another, e.g. through differential N supply and use, we conclude that the utility of the NDVI methodology for developing zone management maps could be improved by using historical records and data for a range of crop types rather than pooling data from a range of seasons.

Advances in precision agriculture in south-eastern Australia. V. Effect of seasonal conditions on wheat and barley yield response to applied nitrogen across management zones

Spatial variability in grain yield across a paddock often indicates spatial variation in soil properties, especially in regions like the Victorian Mallee. We combined 2 years of field data and 119 years of simulation experiments (APSIM-Wheat and APSIM-Barley crop models) to simulate crop yield at various levels of N application in 4 different management zones to explore the robustness of the zones previously determined for an experimental site at Birchip. The crop models explained 96% and 67% of the observed variability in wheat and barley grain yields, with a root mean square error (RMSE) of 310 kg/ha and 230 kg/ha, respectively. The model produced consistent responses to the observed data from the field experiment in 2004 and 2005 where a high and stable yielding zone produced the highest dry matter as well as grain yield, while a low and variable zone recorded the lowest grain yield. However, from the long-term (119 years) simulation, the highest median wheat yield value was obtained on the low variable zone (2911 kg/ha) with high N fertiliser application, while the lowest was obtained on the high variable zone (851 kg/ha). Similarly, the highest barley yields (1880–3350 kg/ha) occurred on the low variable zone using the long-term simulation. In 10–20% of years the highest yield occurred in the high-yielding zones, with the variable and stable zones changing rank with interactive behaviour only under early-sown conditions. Our analyses highlight the problem of using a limited range of seasons of different weather conditions in agronomy to make strategic conclusions as the long-term simulation did not confirm the original yield zone determination. The challenge ahead is to predict in advance the seasons where application of N fertiliser will be beneficial.

Utilizing airborne electromagnetic (EM) data, high resolution DEM and hydrogeological information to derive customised products for natural resource management along the River Murray corridor

To improve on earlier hydrogeological models and to better manage the River Murray floodplain environment and water resources from salinity and irrigation impacts, stakeholders in the New South Wales and Victorian Mallee worked with project scientists to identify hydrogeological parameters that might be collected from existing data sets to help resolve land and water management issues (Lawrie at al., 2008). Several areas where improved information were identified, including the extent and thickness of the river flush zone, salt stores in both the unsaturated and saturated zones, and the thickness, extent and depth to the top of the Blanchetown Clay and other clay units across the floodplain and its adjacent uplands. Previous AEM-based studies have demonstrated the potential for these data to provide high geospatial resolution of key elements of the hydrogeological system (Walker et al., 2004). An airborne electromagnetic (AEM) survey was flown in early 2007 along a 450 km stretch of the Murray River and its floodplains in Victoria from the South Australian-Victorian border to Gunbower. The data were acquired under the auspices of the Australian Government?s Community Stream Sampling and Salinity Mapping Project, and were managed by the Bureau of Rural Sciences. This survey utilised a Fugro RESOLVE frequency domain system, with flight lines at 200m line spacing, and oriented at a high angle to the river corridor. RESOLVE is a six frequency EM system mounted in a bird towed beneath a helicopter at a nominal altitude of 30 m. The bird contains horizontal coplanar coils and measure EM responses at 390 Hz, 1798 Hz, 8177 Hz, 39470 Hz and 132700 Hz. It also has one coaxial coil pair which measured a response at 3242 Hz. This paper presents methods for mapping the thickness of Blanchetown Clay in the highlands of the areas surveyed during the course of this work, and the distribution of near surface clay across the floodplains, specifically at Lindsay-Wallpolla, Lake Victoria, Darling River and its anabranch.

Predicting pasture and sheep production in the Victorian Mallee with the decision support tool, GrassGro

The GrassGro decision support tool was designed to quantify sheep and pasture production in response to management and climate variability in temperate Australia, and has been tested in temperate but not low-rainfall Australian conditions. Data from field experiments and from on-farm monitoring was used to test GrassGro predictions of annual and perennial pasture production, and sheep production at 4 locations throughout the Victorian Mallee, which is a low-rainfall area (275–375 mm annually). Predictions of long-term pasture production were then made. Predictions of the herbage biomass of annual pastures closely matched observed data for both a sandy loam (1991–2002 data) and a whole paddock (combining sandy loam and loam and sand) (2001–2002 data) soil type, at several locations across the Victorian Mallee. Linear regression between observed and simulated (April to September) data produced coefficients, significance and root mean square error of r2 = 0.81, P&lt;0.001, 217 kg DM/ha, respectively, for sandy loam soil types and r2 = 0.94, P&lt;0.001, 72 kg DM/ha, respectively, for whole paddock soil types. A series of simulations for individual years from 1970 to 2002 quantified the large impact of climate variability and demonstrated that seedbank and location, but not soil fertility, had a large influence on annual pasture production. However, GrassGro underestimated the production of the perennial pasture, lucerne (r2 = 0.2). GrassGro was also unable to adequately predict sheep production because it failed to take into account the sparse, clumpy structure of the low biomass pastures typical of this region. Methods to improve GrassGro were identified and included: (i) the need to adjust sheep intake from low biomass, sparse pastures, (ii) the ability to predict summer growing and autumn growing plant species, (iii) the ability to graze crop stubbles and (iv) refinements to the coefficients of equations used to model lucerne growth.

Impact of subsoil constraints on wheat yield and gross margin on fine-textured soils of the southern Victorian Mallee

The APSIM-Wheat module was used to investigate our present capacity to simulate wheat yields in a semi-arid region of eastern Australia (the Victorian Mallee), where hostile subsoils associated with salinity, sodicity, and boron toxicity are known to limit grain yield. In this study we tested whether the effects of subsoil constraints on wheat growth and production could be modelled with APSIM-Wheat by assuming that either: (a) root exploration within a particular soil layer was reduced by the presence of toxic concentrations of salts, or (b) soil water uptake from a particular soil layer was reduced by high concentration of salts through osmotic effects. After evaluating the improved predictive capacity of the model we applied it to study the interactions between subsoil constraints and seasonal conditions, and to estimate the economic effect that subsoil constraints have on wheat farming in the Victorian Mallee under different climatic scenarios. Although the soils had high levels of salinity, sodicity, and boron, the observed variability in root abundance at different soil layers was mainly related to soil salinity. We concluded that: (i) whether the effect of subsoil limitations on growth and yield of wheat in the Victorian Mallee is driven by toxic, osmotic, or both effects acting simultaneously still requires further research, (ii) at present, the performance of APSIM-Wheat in the region can be improved either by assuming increased values of lower limit for soil water extraction, or by modifying the pattern of root exploration in the soil profile, both as a function of soil salinity. The effect of subsoil constraints on wheat yield and gross margin can be expected to be higher during drier than wetter seasons. In this region the interaction between climate and soil properties makes rainfall information alone, of little use for risk management and farm planning when not integrated with cropping systems models.

Do some naturalised legumes have the potential to improve pasture production in the Victorian Mallee?

Some naturalised (not commercialised or deliberately sown) annual pasture legumes may be valuable pasture components, but their production relative to commercial species is poorly defined. This study aimed to determine the relative productivity, morphology, nutritive value, ecotype variation and sulfonylurea tolerance of some naturalised species in the Victorian Mallee. A series of 3 glasshouse and 2 ungrazed field experiments compared the production of haresfoot clover (Trifolium arvense L.), little woolly burr medic (Medicago minima L.), spineless M. minima, and M. monspeliaca (L.) Trautv. with the commercial species strand medic (M. littoralis Loisel cv. Herald) and barrel medic (M. truncatula Gaertn cv. Paraggio). The crude protein and in vitro digestibility of leaf and stem components were similar among species. The proportion of leaf was associated with species maturity, with later maturing species having a greater proportion of leaf at each harvest. There was a range of 52 days among species for date of first flowering. T. arvense produced similar or more biomass than the commercial species in spring, but had lower winter production. A 38-day range in days to first flower and a 2-fold range in winter biomass production among T. arvense ecotypes indicate potential for selection within this species. T. arvense also appears to have greater tolerance of triasulfuron residues than M. littoralis. Spineless M. minima requires further evaluation for persistence in this environment, but the low production of M. monspeliaca limits its value as a component of pastures. T. arvense, spineless and spiny M. minima all have some characteristics which could enhance pasture production in low-rainfall, low-input mixed farming systems.

Crop stubbles are as important for sheep production as annual pastures in the Victorian Mallee

The impact of different management strategies on production and profit can be evaluated with knowledge of how sheep production responds to changes in the available feed base and sheep or pasture management. This study aimed to quantify on-farm pasture and sheep production in mixed sheep and cropping systems in the Victorian Mallee of south-eastern Australia (325 ± 50 mm annual rainfall) as a prelude to computer simulation modelling. During 2001 (average rainfall) and 2002 (extreme drought) pasture production, the feed base and sheep production were monitored in 15 paddocks on 5 properties located across the region. Crop stubbles were the major source of feed for 6 months of the year, enabling ewes to maintain liveweight. There was more variation in pasture parameters between paddocks at the 1 location than between locations. The botanical composition, plant density, soil fertility and management were key variables associated with between-paddock variation in pasture production. Variation in pasture production between years was larger than within-year differences. In contrast, stocking rates were not much lower in the drought year of 2002 than in 2001. This study suggests there is potential for management to improve pasture production, and demonstrates the importance of feed sources other than annual pasture for sheep production in environments where the annual pasture growing season is short.

The impact of point of care testing on diabetes services along Victoria's Mallee Track: Results of a community-based diabetes risk assessment and management program

In the State of Victoria in Australia, diabetes is considered one of the top 10 health problems for people living in the rural Mallee Track region (which is centred on the town of Ouyen and extends west to the border with South Australia). A project entitled 'Diabetes Management Along the Mallee Track' was conducted through a Rural Chronic Disease Initiative (RCDI) program grant from the Australian Government's Department of Health and Ageing, Canberra, with the aim of improving the delivery of diabetes services in this region. The project's aims were achieved through the implementation of a community risk assessment program and the establishment of an integrated, multidisciplinary 'one-stop' service for the management of people with diabetes. The use of on-site point-of-care (POC) pathology testing equipment was the key component of both arms of the project. Community risk assessment sessions were held in seven towns across the Mallee Track region using a local settings approach. Risk assessment included POC pathology testing for glucose and lipids, as well as blood pressure, age, personal and family history of diabetes, smoking status, and self-assessed weight and level of exercise. The multidisciplinary 'one-stop' service for the management of people with diabetes involved having a single appointment with their local GP, during which time they met the local diabetes educator and podiatrist as well as the GP, and on-site POC testing (POCT) performed for haemoglobin A1c (HbA1c), urine albumin : creatinine ratio (ACR), lipids and glucose. A written survey was conducted among patients with diabetes, local GPs and local health professionals to assess the level of satisfaction with the project and the use of POCT, and to assist policy development for the future planning and development of diabetes services along the Mallee Track region. Risk assessment: 320 adults were assessed for their risk of diabetes during community sessions (representing approximately 20% of the adult population of the region). Two-thirds of people tested had equivocal random blood glucose levels (5.1-11.0 mmol/L), while hypertension and high cholesterol were found in more than one-third. Management of established diabetes: 49 people with known, established diabetes were initially entered into a Central Diabetes Register (with 5 more joining the register since). These diabetes patients (n = 54) have now been monitored by POCT for a mean of 10 months (range 3-18 months). Since the introduction of the 'one-stop shop', the percentage of persons achieving optimal glycaemic control (HbA1c <7%) has increased by 30% (from 33% to 63%), the percentage achieving controlled glycaemia (HbA1c < 8%) has increased by 32% (59% to 91%), while the number exhibiting poor control has reduced by 7% (13% to 6%). The mean HbA1c has fallen from 7.6% at the commencement of the program to 7.1% (p = 0.03, paired t-test). Falls in cholesterol and blood pressure were also observed. Satisfaction with new management services for diabetes: 36 patients with diabetes (73% of all known diabetes patients in the region at the time) completed satisfaction questionnaires. There was overwhelming support within this group for the use of POCT as part of their management, because it was convenient, encouraged self-management and enhanced doctor-patient relationships. The proportion of patients with diabetes who were satisfied/very satisfied with the available diabetes services was significantly greater following the introduction of the project (before: n = 18 (64%), after: n = 29 (91%), chi2 = 6.10, p = 0.01). Doctors agreed that the immediate availability of POCT results at the time of consultation was convenient for them, contributed positively to patient compliance and improved their relationship with the patient. Health professionals felt confident in using the POC analysers and believed the program had raised community awareness about diabetes and enhanced community ownership. Point-of-care pathology testing has enabled the introduction of a community-friendly risk assessment program for diabetes and provided a convenient and rapid service for monitoring the control of diabetes in people with established disease in the Victorian Mallee Track region. The number of diabetes patients accessing diabetes services has more than doubled since the introduction of the program. All community and health professional groups surveyed agreed that the POC model delivered as part of this project should be available to all people throughout the Mallee Track region. The model, although conducted in a small rural community, has the potential to form a suitable template for the broader introduction of POCT services for diabetes in rural and remote communities across Australia. As an independent measure of the success of the program, the Australian Government's Department of Health and Ageing selected the Diabetes Management Along the Mallee Track project as one of three demonstration projects from the RCDI grants for showcasing to all rural health services in Australia through the production of an education resource called 'Building Healthy Communities'.

Limitations to pasture and sheep enterprises and options for improvement in the Victorian Mallee

A survey of 29 sheep producers was conducted to benchmark current sheep production practices and producer attitudes to sheep and pasture management in the Victorian Mallee. This report describes the farming systems, defines current sheep management practices and identifies management issues that are limiting production. It also highlights limitations of adoption, suggests potential adoption rates of specific practices by producers, and estimates increases in productivity achievable. Sheep producers could achieve small gains in farm productivity (an estimated average 0.3% annually) by adopting sheep management practices including using superior genetics, reducing ram numbers and introducing supplementary feeding. Possible reasons why recommended practices have not been adopted are discussed. The difficulty of integrating sheep into current short cropping systems was considered to be a key limitation to the adoption of management that could substantially increase productivity, such as higher stocking rates and winter–spring lambing. Important benefits to both productivity and environmental sustainability may be achieved through the replacement of fallowed land with improved pastures. However, a lack of data on the feed base and sheep production in relation to a changing feed base made it impossible to estimate the size of these benefits. It was concluded that further research is needed to collect data and benchmark pasture and livestock enterprises to allow quantification of the potential impact on farm profit of changes to pasture and sheep management in this region.

Evaluating physicochemical constraints of Calcarosols on wheat yield in the Victorian southern Mallee

Soil salinity, sodicity, and high extractable boron (B) are thought to reduce wheat yields on alkaline soils of south-eastern Australia; however, little quantitative information on yield penalties to edaphic constraints is available. The relationships between wheat yield of a B-tolerant cultivar and soil physicochemical conditions in the Victorian Mallee were explored using ridge regression analysis, using natural variation in the field. Wheat yields in the survey ranged from 1.3 to 6.1 Mg/ha, with low yields attributed to inadequate soil water supply during pre-anthesis growth. Crop sequences, fallow–wheat, and pulse–wheat left greatest soil water prior to sowing of the wheat crop, and lucerne–wheat the least. A descriptive model explained 54% of variation in wheat yield, with rainfall around anthesis, available soil water in the 0.10–0.40 m layer, nitrate in the 0–0.10 m layer at sowing and salinity, and sodicity in the 0.60–1.00 m layers being important factors. Subsoil salinity (ECe) and sodicity (ESP) appear to be effective surrogates for estimating the likelihood of water extraction in the deep subsoil. The analyses suggest that subsoils need to have an ECe &lt;8 dS/m and ESP &lt; 19% for crops to make use of water deep in the profile. Although soluble B ranged from 2 to 52 mg/kg in the 0.60–1.00 m layer of the alkaline soils considered, B appeared to have little correlation with root growth, water extraction, or yield of wheat, which has been attributed to B-tolerance of the cultivar tested and/or the overbearing effect of high Na+ in these soils.

Drainage and change in soil water storage below the root-zone under long fallow and continuous cropping sequences in the Victorian Mallee

A field study investigated drainage and changes in soil water storage below the root-zone of annual crops on a sandy loam soil in the Victorian Mallee for 8 years. It was designed to compare the effects of the common long (18-month) fallow in a 3-year rotation (fallow–wheat–pea, FWP) with a rotation in which the fallow was replaced with mustard (Brassica juncea), viz. mustard–wheat–pea (MWP). Drainage was measured over 2 periods (1993–98 and 1998–2001) using 9 in situ drainage lysimeters in each rotation. The first period of ~5 years was drier than average (mean annual rainfall 298 cf. 339 mm) and drainage was low and variable. Drainage was greater under the fallow rotation (average 0.24 mm/year) than under the non-fallow rotation (average &lt;0.01 mm/year). The result for the fallow rotation did, however, include one lysimeter that recorded substantial drainage (10.6 mm over the 5 years). During the second period of measurement (~3 years), rainfall was above average (mean annual rainfall 356 cf. 339�mm) and drainage was greater. On average, drainage from the fallow rotation was 6.7 mm/year compared with the non-fallow rotation at 4.0 mm/year. There was again substantial variation between lysimeters. One lysimeter under MWP recorded 31.4 mm/year, and as in the earlier drier period, there were many lysimeters that recorded no drainage. During the drier first period (1993–98), changes in soil water storage between 1.5 and 5.5 m depth confirmed the tendency of the fallow rotation to increase deep drainage. Despite increases and decreases in subsoil water storage during the study, the cumulative change in water storage was positive and greatest under FWP (range: 2.8–14.8 mm/year, ave. 9.6 mm/year) compared with MWP (range: 5.3–9.8 mm/year, ave. 7.4 mm/year) cropping sequences. Overall, the long fallow system has the potential to increase deep drainage by approximately 2 mm/year compared with a fully cropped system, over a wide annual rainfall range (134–438 mm). Further, this experiment reinforces the focus for the reduction of fallow practices for dryland salinity control in the Mallee region.

Crop growth, yield and water use in long fallow and continuous cropping sequences in the Victorian mallee

The agronomic implications of substituting mustard (Brassica juncea) for long (winter) fallows were investigated in a 6-year field experiment by comparing 2 cropping sequences (fallow–wheat–pea v. mustard–wheat–pea) in the semi-arid Victorian mallee. Production and water use of wheat, pea and mustard were measured. Grain yields ranged from 0.1 to 2.4 t/ha for wheat (mean 1.72 t/ha after fallow and 1.22 t/ha after mustard); from 0 to 0.6 t/ha (mean 0.22 t/ha) for mustard and from 0 to 1.4 t/ha (mean 0.8 t/ha) for field pea, strongly reflecting variable seasonal conditions (in-crop rainfall range from 84 to 231 mm). Mustard was shown to be a potential replacement for long fallow producing additional yield benefit (mustard + wheat) in one year. However, under drought conditions it introduces severe penalties to wheat growth and yield compared with the traditional fallow cropping system. Further, mustard did not affect water use, growth, or yield of the second crop after wheat (in our case field pea). This study highlights a conflict between developing farming systems that are productive, environmentally and socially acceptable under variable weather conditions and yet uphold the regional need to reduce dependence on fallowing. Further analyses of weather patterns and other crop choice strategies are needed to help develop better management strategies for the mallee region of Australia.

Trapping efficiency of Ugglan traps and Longworth traps for house mice in south-eastern Australia

Small mammal studies require traps that efficiently capture the target species, are cheap, and preferably have no adverse effects on the animals. We compared the trapping efficiency of Ugglan multiple-capture live-traps with Longworth single-capture live-traps in field studies of house mice (Mus domesticus) in the Victorian Mallee of south-eastern Australia. More captures and recaptures were made with Longworth traps and fewer mice died while in these traps. There was no difference in mean body mass of captured mice between Ugglan and Longworth traps but relatively more males were trapped with Ugglan traps. The trapping mechanism that requires the mouse to activate a trap door, and open mesh wire along the sides of the Ugglan trap may be the main reasons for low trappability. In addition, the open sides could have contributed to the lower survival observed for mice in Ugglan traps. Although Ugglan traps have the potential for multiple captures, are cheaper, and their trapping mechanism is less prone to failure than Longworth traps, they were not as efficient in trapping house mice at low and medium densities.