Seminar details are included in the expandable boxes below.
Friday 4th August 2017
In 1987, a group of entomologists from several institutions embarked on a long-term study of Helicoverpa ecology in non-cropping areas of inland Australia. This work has continued intermittently until this year, with funding from CRDC, GRDC, RIRDC, ARC and the Cotton CRC. We made a total of 79 field trips to the region, which encompassed inland areas of NSW, Qld, SA, WA and NT. Over 2000 sweep net samples for Helicoverpa spp. larvae have been made on over 230 different plant species, mostly natives. H. punctigera was by far the most common species, with 50.5% of samples yielding larvae. Only 4.2% of samples yielded H. armigera larvae, and these were mostly in the northeast of the study area. This is despite the fact that in the laboratory H. armigera larvae survive and grow well on some key inland hosts. H. punctigera larvae were found on 122 plant species from 18 families. Of these, 120 were new host records. Host suitability was assessed using the matrix of Zalucki et al. (1994; Aust. J. Zool. 42, 329), which plots relative incidence against relative abundance. The best hosts were annual daisies and legumes. Annuals from several other families were also commonly recorded as hosts. Perennial species were less suitable. Crops sampled around the margins of the study area supported fewer larvae than the native hosts, indicating the importance of native hosts in the continental population dynamics of H. punctigera.
This thirty year study has provided a comprehensive picture of short and long term changes in host plant abundance in different inland habitats (floodplains, grasslands, acacia shrublands, chenopod shrublands, sandy deserts and stony downs). The Millenium Drought in 2001-2009 which severely affected southeast Australia (Van Dijk et al. 2013, Water Resour. Res., 49, 1040-1057) significantly affected host plant abundance in the acacia shrublands and to a lesser extent in the grasslands. Floodplains, sandy deserts, stony downs and chenopod shrublands were not affected. Host plants were recorded in about 61% of the sites surveyed in the acacia shrublands before the drought, and only in about 28% after the drought (P<0.001)). In the grasslands, about 49% of these sites supported host plants compared with 35% after the drought (P=0.018). The abundance of host plants also declined in many sites, and good hosts (such as the daisy Rhodanthe floribunda) were replaced by plants which supported fewer larvae (such as the Malvaceous plant Sida platycalyx). The impact of medium-term changes in climate, represented by the Millenium Drought, on Helicoverpa ecology, and the implications for management of these pests will be discussed.
Wednesday 7th June 2017
Salt tolerant pasture species represent a valuable opportunity to intensify agricultural production in low-rainfall areas where saline land and or water (e.g. mine-site dewatering) are allocated to pastoral systems. Inherently variable in ionic composition and concentration, the response of plants to saline soils and groundwater are difficult to predict. Existing and novel approaches were applied to tropical and sub tropical pasture species to identify: mechanisms of tolerance to root-zone salinity; the individual effects of osmotic stress (OS) and osmotic stress and ion toxicity (OST) on plant growth and water use and; practical upper salinity limits for soil solution salinities. Generally, salt tolerant tropical and subtropical pasture species, including some glycophytes, should be considered for intensification of agricultural production in areas where root-zone salinity is an issue. The ability of glycophytic pasture species such as lucerne and leucaena to exclude Na+ at the root level, when root-zone Ca2+ was adequate, has potential value under root-zone salinity. However, if OST occurred, severe reductions in growth and plant water use were observed, potentially limiting glycophytes to situations where low soil solution salinities (2-5 dS/m) and adequate Ca2+ availability can be maintained. The capacity of halophytic Rhodes grass to safely accumulate ions to high concentrations in plant tissues at moderately high root-zone salinity (16 dS/m), whilst maintaining adequate plant growth and water use, meant it was the best option (of the species tested) for cultivation in tropical and subtropical areas affected by root-zone salinity.
Hayley is an agronomist and Lecturer in Tropical Agriculture at The University of Queensland. Her research interests range from the systems level of ruminant livestock production down to cellular processes, studying the physiological responses of pastures to abiotic stress.
Hayley completed her PhD at the University of Queensland, studying the effects of root-zone salinity on plant production and water use of tropical and subtropical pasture species adapted to southern Queensland. She has experience in the intensive and extensive grazing systems of northern Australia, and agricultural research in South East Asia. Hayley has worked on a variety of research and extension activities associated with feed base improvement, plant breeding and toxicology.
Monday 20th February, 2017.
Modern farming systems engage in less tillage and suffer from nutrient deserts in the subsoil. What root system characteristics should we aim for to move agriculture into the future and optimise nutrient recovery from increasingly ‘unnatural’ systems?
Monday 12th December 2016
Contamination of farm soils with toxic metals has become a serious problem across the world. Overuse of chemical fertilisers and other agrochemicals are to be blamed for Cd and As contamination in Sri Lanka, particularly in the farming areas. The soil contamination is the most probable cause of chronic kidney disease in rural areas. My PhD study will investigate the fate and behaviour of Cd and As in co-contaminated systems, aim to understand factors influencing mobility and bioavailability in the Dry Zone soils of Sri Lanka and assess options for effective treatment of the As and Cd co-contaminated soils. This presentation will give you a brief overview of my PhD study and how I will achieve the aims.
Monday 5th December 2016
Root carbon inputs into soil from a C4 root system
In the past decade there has been considerable research interest in soil carbon, particularly on the larger scale of soil types and land uses. Root and root exudates have received little attention in regards to their contribution to the soil organic carbon pool. This presentation will give a brief overview of the contribution of root derived carbon inputs into the soil organic carbon pool, as the root system grows across time.
δ13C Abundance and Distribution in Soil Fractions under Vetiver and Native Pastures
Soil carbon fractions indicate the resilience or otherwise of carbon stored in soils and its relative rate of decomposition and cycling. Where a change of vegetation cover from C3 to C4 species takes place, δ13C abundance in SOC fractions and their distribution in soil profiles can be used to determine the quantity, rate and distribution of “new” carbon added to the soil system. In this work, we examined the isotopic signature (δ13C) of two soil fractions, their quantity, vertical distribution and turnover rates under Vetiver (C4) compared with native (C3) grasses at a research site in Gunnedah Resource Center, NSW. Vetiver is a fast growing tropical grass used extensively in Africa and Asia for soil conservation works and it has been proposed that this grass has considerable potential for efficient storage of additional soil carbon. The δ13C distribution in the soil profile was used to explore the nature and proportion of soil carbon contributed by Vetiver.
Storage and depth distribution of dissolved organic carbon under different land-uses of NSW Australia
Carbon accumulation in surface soils is well documented but very little is known about the mechanisms and processes that result in carbon accumulation and long-term storage in the deeper soil profile. We investigated the quantity and distribution of DOC through the profile under three different land-uses (woodland, pasture and cropland) in northern NSW, Australia. This research provides new insights into the mechanisms and importance of DOC to the soil carbon cycle in Australian soils.
Monday 21st November 2016
Most of the world’s grain production is derived from crops that are either naturally self-pollinating (wheat, rice, barley, and most grain legumes), or are deliberately self-pollinated during the breeding process (F1 hybrid crops such as maize, canola, sorghum). In traditional breeding methods, selfing is exploited to accurately select superior inbred lines. Relatively few lines survive the selection process and effective population size tends to be lower than in animal breeding. Cycle time (the interval between crossing events) tends to be longer, and the rates of recombination are lower, than in animal breeding. We propose a unified method of plant and animal breeding where lines are selected in early generations of selfing, breeding value is based on all records in the pedigree, and optimal contribution selection is used to promote long-term genetic progress. Cycle time is reduced, and effective population size increases. Models of the method, developed with UNE colleagues, suggest that the average rate of increase in economic index, including yield, disease resistance and grain quality, is double that of traditional methods.
Monday 14th November 2016
Bronze Age smelting sites in central Thailand have been identified as playing a major role in regional cultural development. However, the extent of contamination with heavy metals such as copper at these sites, and any resultant risk to humans or the environment, is completely unknown. The potential for the use of portable x-ray fluorescence technology to identify these sites and contamination hotspots was assessed and found to be an accurate and efficient alternative to the traditional wet chemistry aqua regia technique for copper when appropriate analysis settings were used. Current mobility of soil copper was also assessed, and while this was found to be relatively immobile, values were still high in absolute terms. Preliminary sampling also indicated transfer into plant material.
Monday 10h October 2016
The economy of Bangladesh is mainly governed by agriculture. Organic Farming is gradually increasing in Bangladesh in particular through efforts of NGO’s and private entrepreneurs. This presentation will give a brief idea about the present status of organic farming in Bangladesh with respect to production, trade, research and development as well as governmental interruption to promote organic farming.
Monday 26th September 2016
The general perception of auxin is that it is a growth hormone primarily involved in vegetative development. However, the highest IAA levels are found in developing fruits/grains. I will present evidence for grain-specific IAA biosynthesis genes and transcriptional regulators that are exclusively expressed during endosperm cellularisation in developing cereal grains. In addition, genes for storage proteins, starch biosynthesis enzymes and a number of signalling proteins appear to be regulated by auxin in conjunction with another well-studied transcriptional regulator. I conclude that there is strong evidence for a role for auxin in the sink strength of developing grains and the initiation of endosperm starch production.
Monday 5th September 2016
Soil health is an essential requirement of a sustainable, functioning agroecosystem. Tracking soil health to determine sustainability at the local level largely falls to farmers, even though they often lack access to critical information. We examine farmers’ participation in gathering soil information at the farm and paddock scale over the last two decades in Australia and the United States, by reviewing national-level reporting of farmer use of soil testing. The level of participation in soil testing has remained stable in the last two decades, with only 25% and 30% of landholders, respectively, participating nationally, in either country. The review revealed national-level reporting has a number of limitations in understanding farmers’ use of soil information and, in particular, fails to indicate the frequency and intensity of soil testing as well as farmer motivation to test soil or what they did with the soil information. The main use of soil testing is often stated as “determining fertilizer requirements”, yet data show soil testing is used less commonly than is customary practice. The rhetoric is heavy on the use of soil testing as a decision tool, and that it guides best practices. However, given that only a quarter of farmers are soil testing, and doing so infrequently and in low densities, the level of information on soil health is poor.
Monday 29th August, 2016.
Monday 22nd August, 2016.
Sub-Antarctic Macquarie Island is one of Australia's World Heritage Areas. Like many other Southern Ocean islands, Macquarie Island has a history of exploitation, degradation, and introductions of exotic species. In 2014 Macquarie Island was declared free of rats, mice, and rabbits; the last of the remaining mammals introduced to the island. Since the removal of rabbits there has been rapid recovery in the native vegetation. However, some exotic species remain, including five plants. For the ongoing recovery and management of Macquarie Island it is important to understand the potential impacts of all exotic species still present. My PhD focuses on one of the exotic plants, Stellaria media (chickweed), in order to better understand the dynamics of invasive plant species on Macquarie Island following the removal of rabbits.
* Featuring photography of Macquarie Island landscapes and wildlife.
Supervisors: Professor Brian Sindel, Associate Professor Paul Kristiansen, Dr Sue Wilson (UNE); Dr Justine Shaw (Australian Antarctic Division).
Monday 15th August, 2016.
Forage legumes can contribute to intensifying crop and livestock production in smallholder farming systems. However, the impact of forage legumes varies with social, economic and agro-ecological factors. Conducted in West Timor, Indonesia, this research explored the trade-offs and impacts of forage legumes, identifying optimal management strategies and target farm typologies. We found that forage-livestock intensification mainly benefits food- secure households with high resource endowments, while the trade-offs for poorer food- insecure households are too large. Forage-livestock intensification that minimises trade- offs and labour inputs is more likely to achieve the potentially large economic benefits.
Monday 8th August, 2016.
Urban agriculture is estimated to make up nearly 6% of the world’s crop land and is practiced worldwide by as many as 800 million people. Yet the sector is mostly informal and has been the subject of very limited academic research, meaning that we know very little about it. Robert is investigating the economics and ecology of these systems, using market, private and community gardens in Sydney and the Illawarra as case studies. Preliminary results imply that, whilst most of the gardeners involved carry out the activity as a hobby, rather than professionally, and are far more interested in quality of produce over quantity some still produce yields of fruit and vegetables that, on a per hectare rate, exceed those of most commercial farms. However it appears that these gardens are labour intensive, with only the most efficient being economically viable and even then only marginally so.
Monday 25th July, 2016.
Soil biology and particularly microbiology has come a long way since Leonardo De Vinci said "we know more about the celestial bodies than we did the soil under our feet." The days of culturing a small proportion of the soil microbes have been superseded by DNA and high throughput techniques, but that should not mean that classical methods are forgotten. How else will we understand what the new organisms, whose DNA we find, do in our systems?
In this seminar I reviewed how things have changed over my 25 years as a researcher, how the Archaea have arisen, how pesticide legislation is altering nematode populations and how plant border cells are more akin to our own immune system than many would think. Samieh Eskandari and Katherine Polain joined me to inform the audience about the very latest research on mycorrhizal importance to cotton in sodic soils and how we can use 18O on phosphorus to determine microbial activity. I’m not sure what the future will look like, but large amounts of data will be involved and our power to interrogate it will also grow.
Monday 6th June 2016.
A/Prof Paul Kristiansen has been carrying out projects and working with Vietnamese colleagues since 2009. Having completed eight projects with five more in progress, he has wide experience in the land use systems and socio-economics of Vietnam. In this talk, Paul described the current situation facing agriculture in Vietnam, highlighting some of the key opportunities and challenges for various parts of the country. Current links between UNE and Vietnam are strong across several disciplines, especially in agriculture, environmental management and agribusiness.
Monday 23rd May 2016
Supervisor: Dr Sue Wilson.
Monday 11th April 2016
Internationally renowned for his work on signalling mechanisms of biotic and abiotic stresses in plants, Professor Hirt’s current research is focused on molecular mechanisms induced by microbial associations that enable plants to adapt to extreme environmental conditions, and to promote use of the appropriate rhizosphere partners for sustainable crop food production. His research has also demonstrated that Salmonella enterica, a major cause of food poisoning in humans, escapes the plant immune system and accomplishes colonization of plant tissues. Author of 165+ publications with 20,954 citations, and an h-index 68, Dr Hirt has also served in administration as the Head of the Department of Plant Molecular Biology, University of Vienna (2006-2007), Director of URGV Plant Genomics, Evry, France (2008-2013), Director of Center of Desert Agriculture, KAUST, Jeddah, KSA (2014- 2015) and is currently Head of Plant-Microbe Group at the Center of Desert Agriculture at KAUST. Additional information can be found online.
2014 and 2015 Seminars
Wednesday 14th October 2015
Human societies have always been highly dependent upon healthy soils. This is because the earth beneath our feet underpins the environment we live in at local, national and ultimately global scales. Soils provide a platform to live upon and are fundamental to the provision of the majority of our food. They support all terrestrial habitats, store and filter water, cycle carbon and nutrients, are intimately involved in climate regulation, and even tell us about our past via the archaeology they hold.
Soils are also remarkable systems. They are extremely complex both in terms of the variety of their constituents and the way these are arranged in space, from nanometres to kilometres. Soils are dynamic and reactive entities teeming with a huge variety of life, supporting levels of biodiversity that almost defy imagination. The amount of living material below ground always matches or exceeds that aboveground, and there are typically tens of thousands of microbial species and many hundreds of other tiny organisms in a handful of soil from almost anywhere. These communities can be thought of as the biological engine of the earth, working to drive and regulate the majority of the key processes and functions which soils deliver.
But there's more to work than life - soils function by virtue of the way they are put together and the interactions that occur between the myriad of physical, chemical and biological components within. These all occur in the massively complex labyrinths of pore networks present in most soils. Throughout my life I've been exploring this fascinating 'inner space', the nature of the organisms that live in there, and how they make soil systems operate.
Dr Karl Ritz graduated in Agricultural Botany from the University of Reading in 1981, and completed a PhD in grassland ecology at the University of Bristol in 1984. He then moved to Scotland to lead research programmes at the Macaulay Institute for Soil Research (1984-7) and the Scottish Crop Research Institute (1987-2002). From 2002-14, he held a Chair at Cranfield University in the National Soil Resources Institute, and is currently Professor of Soil Biology at the University of Nottingham.
He is a Chief Editor of the high-ranking journal, Soil Biology Biochemistry and has held long-standing editorial roles with FEMS Microbiology Ecology, Mycological Research and the Journal of Soil Science and Plant Nutrition, as well as editorial roles for several books.
Wednesday 9th September 2015
Supervisors: Dr David Backhouse, Dr Susan Wilson, Professor Annette Cowie.
Wednesday 22nd July 2015
We investigated the stability of whole profile soil organic carbon (SOC) based upon three mid-infrared predicted fractions – particulate organic carbon (POC), humus organic carbon (HOC) and resistant organic carbon (ROC) – at 100 sites across Eastern Australia. Our aim was to identify the controls on SOC stability down the whole soil profile, in particular relating to climate, site and human influences. To do this we used three data-mining algorithms (randomForests, gradient boosting machines and multiplicative adaptive regression splines) to identify and assess the controls on the relative proportions of the three fractions down the soil profile. Depth was the key control on all three fractions, with the proportion of POC decreasing, and the proportion of HOC carbon increasing with increasing depth. SOC was strongly linked with POC, suggesting that the soils in the region are input driven. HOC and ROC were controlled additionally by climate and soil physico-chemical properties, with SOC being less important to these fractions. Human influences (land-use and management) were not important to the fractions, implying that the controls humans can exert on SOC stability in these environments may be limited.
Wednesday 27th May 2015
Wednesday 20th May 2015
Supervisors: Dr Sue Wilson, Dr Matt Tighe, Associate Professor Lily Pereg
Wednesday 6th May 2015
Supervisors: Professor Brian Sindel, Dr Paul Kristiansen and Associate Professor Robin Jessop.
Wednesday 1st April 2015
Root system architecture is an important trait of cereals that influences nutrient acquisition from the soil. The ability of cereal species to recover nutrients from nutrient enriched patches at depth may vary genetically. Quantifying any existing variation may allow growers to select wheats lines better able to exploit the nutrient band at depth and may also help to decide fertiliser placement either near the surface or deeper in soil. Ten wheat and 5 barley varieties that are commonly grown in the northern grain region were selected and screened for both root proliferation response in a phosphorus band at depth and recovery of phosphorus from germination to maturity. Considerable variation exists in the capacity of the wheat and barley varieties from a nutrient enriched band.
Wednesday 25th March 2015
All complex, multicellular organisms face the challenge of developing and maintaining a safe and efficient system for long distance transport of materials. In vascular plants, water absorbed by roots is transported up the plant in the dead remains of xylem cells. Plants are capable of rapidly transporting water to heights in excess of 100 m, and can extract water from dry soils and saline substrates. To achieve this, plants have evolved a transport system that relies on water sustaining a tensile force, such that the xylem sap is at negative absolute pressures. This mechanism is made possible by the intricate plumbing system that constitutes the xylem tissue of plants. However, this transport mechanism comes with its own set of problems. Most notably, water under tension is prone to cavitation, which results in the formation of a gas bubble (embolism). Embolism reduces the capacity of the xylem tissue to deliver water to the canopy, eventually causing dieback and whole plant mortality. Xylem embolism is exacerbated by environmental stresses and is now considered one of the leading causes of plant mortality resulting from drought stress. Progress in our understanding of plant water transport has been hampered by the inherent difficulty in observing and experimentally manipulating a transport system containing a metastable liquid. Non-invasive imaging techniques such as micro computed tomography (microCT) offer the potential to make direct observations on intact plants at high resolution and in real time. We utilised synchrotron based x-ray microCT to examine xylem function during drought stress in a range of woody plant species. These observations provided unprecedented spatial and temporal resolution of (a) the patterns of embolism spread in the xylem network during dehydration, and (b) refilling of embolised xylem conduits during recovery from drought. These results were compared with widely used techniques that require destructive sampling.
Brendan Choat obtained his BSc (Hons) in 1997 (JCU) and his PhD in 2003 (JCU). From 2003-2005 he worked as a Post Doctoral Fellow at Harvard University in the Department of Organismic and Evolutionary Biology. He held a second Post Doctoral Fellowship in the Department of Viticulture and Enology at the University of California, Davis from 2005-2008. In 2008 he returned to Australia to take up a Research Fellowship at ANU before moving to a Senior Research Lectureship at the Hawkesbury Institute for the Environment (UWS). He is an editor for the PrometheusWiki Project and on the editorial review board of Tree Physiology. In 2010 he was awarded an Alexander von Humboldt Fellowship for Experienced Researchers. In 2013, Dr Choat was awarded an ARC Future Fellowship for his work in mapping drought responses in plants.
Part 1 - Wednesday 15 October 2014
Part 2 - Wednesday 22 October 2014
Professor Peter Gregg joined UNE as a lecturer in agricultural ecology and insect pest management in 1980. His research has focused on the ecology of insect pests of cotton, and the development of alternatives to insecticides for managing these pests. In 2005 he was seconded to the position of Chief Scientist of the Cotton Catchment Communities CRC, and following the winding up of the CRC, he has pursued an active research program as an Adjunct Professor at UNE. Dr. Alice Del Socorro joined UNE as a Research Fellow in 1995, and has worked on many research projects in collaboration with Peter and other colleagues. In 2009, the group led by Peter and Alice registered an attract-and-kill product, Magnet®, which is the first commercial product of this type based on plant volatiles in the world, and one of very few novel pest management products ever commercialised in Australia. This represented the culmination of 13 years of research through various Cotton CRCs, with the assistance of commercial partners AgBiTech Pty. Ltd. The seminar will be delivered in two parts, the first describing the science behind Magnet® and the second describing the processes of patent protection, registration, commercial development and the search for practical applications for the product.
Friday 11 April 2014
Following a successful academic career of 20 years at the Western University, London ON, Canada, Professor Priti Krishna recently joined ERS at UNE as Associate Professor of Plant Biology. With a Master's in Microbiology, PhD in Biochemistry, and postdoctoral training and independent research career in Plant Molecular Biology, Priti has applied her diverse research background to developing pioneering projects and implemented an integrative and collaborative approach to her research, together with rapid adoption of relevant new technologies and approaches as required. Her research is focused on brassinosteroid-mediated stress tolerance and the plant Hsp90 chaperone complex. Both topics are inherently linked with plant stress responses and also span molecular mechanisms underlying other desired traits such as plant architecture, yield, root development etc. Most importantly, brassinosteroids confer broad-spectrum stress tolerance in plants, which is crucial for maintaining crop productivity and quality in the face of global environmental challenges. Keeping in mind ERS's world-class research in the area of root, soil and environmental systems, she now envisions focusing on hormone controlled root traits, which will enhance soil exploration and water and nutrient acquisition.
Wednesday 2 April 2014
Isaac Macharia is a PhD candidate in Agronomy and Soil Science, School of Environmental and Rural Science.
Wednesday 12 March 2014
Graeme Blair is Adjunct Professor of Plant Nutrition at the School of Environmental and Rural Science, university of New England.
Wednesday 26 February 2014
The nature of alkaline, cracking clays and their importance in northern farming systems presents many interesting research questions regarding the sustainability of their long-term use for agriculture. This presentation will reflect on the soil fertility of Vertosols, the nature of their nutrient reserves and the ability of plants to access them and what that may mean for farming systems in the future. Topics addressed will range from P reserves and S dynamics, through K availability and interactions with sodicity and culminate with current research into the nature and plasticity of root responses to nutrient application strategies, in situ, in Vertosols by cereals using 3D tomography. Ultimately it will argue that far more research needs to be directed towards legumes if the constraints of fertility will result in prolonged fecundity in northern farming systems.