Links between carbon and nitrogen cycling processes in forest soils: An innovative approach with both NMR and stable isotope techniques. Understanding the critical links between soil carbon and nitrogen cycling processes in forest ecosystems is necessary for developing effective site management to enhance forest productivity and environmental benefits. In the first application of 14N-nuclear magnetic resonance (NMR) to soil humic acid (HA), we have discovered that surprisingly nitrate-N is prese ....Links between carbon and nitrogen cycling processes in forest soils: An innovative approach with both NMR and stable isotope techniques. Understanding the critical links between soil carbon and nitrogen cycling processes in forest ecosystems is necessary for developing effective site management to enhance forest productivity and environmental benefits. In the first application of 14N-nuclear magnetic resonance (NMR) to soil humic acid (HA), we have discovered that surprisingly nitrate-N is present in soil HAs, with the HA-nitrate N extremely sensitive to forest management practices. This project represents the first attempt to integrate the use of advanced NMR and stable isotope techniques to examine both chemical and biological linkages between carbon and nitrogen cycling processes in Australian and US forest ecosystems.Read moreRead less
Role of stubble management in improving soil fertility. In highly-weathered nutrient-poor soils of the south-western Australia, the amount of nutrients in stubble is critical in nutrient cycling as well as in determining optimal amounts of fertilisers to be applied. Stubble management is therefore an integral part of crop fertilisation and nutrient management. We will characterise nutrient cycling in the stubble-soil-crop continuum in a range of cropping situations. Computer modelling will be us ....Role of stubble management in improving soil fertility. In highly-weathered nutrient-poor soils of the south-western Australia, the amount of nutrients in stubble is critical in nutrient cycling as well as in determining optimal amounts of fertilisers to be applied. Stubble management is therefore an integral part of crop fertilisation and nutrient management. We will characterise nutrient cycling in the stubble-soil-crop continuum in a range of cropping situations. Computer modelling will be used to extend applicability of results over space and time. This project will provide the knowledge required for improving fertiliser recommendations to take into account changes in the cropping systems that have occurred in the last 10-20 years.Read moreRead less
How does warming prevent soil nitrogen availability from declining in response to elevated CO2? The sustainable use of the terrestrial environment depends upon maintaining ecosystem productivity which in turn depends upon nutrient availability within the soil. Increasing levels of CO2 in the atmosphere are known to decrease nutrient availability while warming prevents this from happening. The aims of this project are to determine how warming is able to prevent elevated CO2 concentrations from re ....How does warming prevent soil nitrogen availability from declining in response to elevated CO2? The sustainable use of the terrestrial environment depends upon maintaining ecosystem productivity which in turn depends upon nutrient availability within the soil. Increasing levels of CO2 in the atmosphere are known to decrease nutrient availability while warming prevents this from happening. The aims of this project are to determine how warming is able to prevent elevated CO2 concentrations from reducing soil N availability and hence productivity in a native grassland ecosystems. This is important, as it will allow likely problems caused by global climate change to be predicted by increasing the understanding of the underlying mechanisms as well as improving the management of grasslands in an environmentally sustainable way. Read moreRead less
The role of biological and chemical interactions in the rhizosphere in sustainable intercropping systems. Intercropping can result in large yield increases compared to mono-cropped systems. It is used extensively in China and could be an option for sustainable land-use in Australia. Belowground interactions between intercropped crop species may be important for the yield increase, but they are poorly understood, especially with regard to nutrient availability and soil biology. We will combine th ....The role of biological and chemical interactions in the rhizosphere in sustainable intercropping systems. Intercropping can result in large yield increases compared to mono-cropped systems. It is used extensively in China and could be an option for sustainable land-use in Australia. Belowground interactions between intercropped crop species may be important for the yield increase, but they are poorly understood, especially with regard to nutrient availability and soil biology. We will combine the field experience in intercropping systems of the Chinese scientists with the expertise of the Australian scientists in plant nutrition and rhizosphere ecology to characterise chemical and biological interactions in the rhizosphere governing nutrient availability and the competitive ability of intercropped species.Read moreRead less
The biogeochemical cycles of Ni and Co, a functional approach to ecological restoration of lateritic soils. Nickel is an essential metal for many technologies, and a key component of Australia's resource industry. Nickel exports contribute in excess of Aus$2 billion per annum to the economy. To date, most of Australia's Ni production has come from sulphide ores but the current development of large lateritic Ni operations in Western Australia will result in most production coming from lateritic N ....The biogeochemical cycles of Ni and Co, a functional approach to ecological restoration of lateritic soils. Nickel is an essential metal for many technologies, and a key component of Australia's resource industry. Nickel exports contribute in excess of Aus$2 billion per annum to the economy. To date, most of Australia's Ni production has come from sulphide ores but the current development of large lateritic Ni operations in Western Australia will result in most production coming from lateritic Ni ore. Hence increasing the research effort on ecological restoration of these large opencast mines is essential to ensure an environmentally sustainable Australia. This project will set up strategies to maintain biodiversity using geochemical and biological technologies to minimise environmental risk.Read moreRead less
Ecosystem restoration of bauxite-processing residue sand disposal areas in Western Australia: Important biogeochemical processes and effective fertilisation strategies. Alumina production is one of Australia's most important mining activities. Residue from bauxite-processing must be managed appropriately to minimise detrimental impacts on the surrounding environment. The location of Alcoa's WA Refineries in environmentally- and community- sensitive areas necessitates a detailed understanding of ....Ecosystem restoration of bauxite-processing residue sand disposal areas in Western Australia: Important biogeochemical processes and effective fertilisation strategies. Alumina production is one of Australia's most important mining activities. Residue from bauxite-processing must be managed appropriately to minimise detrimental impacts on the surrounding environment. The location of Alcoa's WA Refineries in environmentally- and community- sensitive areas necessitates a detailed understanding of residue disposal area (RDA) management. Currently little is known about the biogeochemical cycling of nitrogen, phosphorus and carbon in the residue sand despite its importance for sustainable rehabilitation practice. Findings from this project are critical for developing improved fertilisation strategies and protocols for ecosystem restoration of RDAs, which will be applicable both in Australia and overseas. Read moreRead less
Enhanced efficiency fertilisers for agricultural sustainability and environmental quality. Expected benefits will come from reduced environmental impact and improved profitability of farming. These include: demonstrably reduced emissions of nitrogen gases (nitrous oxide (a greenhouse gas), nitric oxide (ozone active), and ammonia (a pollutant and secondary greenhouse gas); less nitrate leaching, soil acidification and nitrogen contamination of water resources; increased flexibility in timing and ....Enhanced efficiency fertilisers for agricultural sustainability and environmental quality. Expected benefits will come from reduced environmental impact and improved profitability of farming. These include: demonstrably reduced emissions of nitrogen gases (nitrous oxide (a greenhouse gas), nitric oxide (ozone active), and ammonia (a pollutant and secondary greenhouse gas); less nitrate leaching, soil acidification and nitrogen contamination of water resources; increased flexibility in timing and method of fertiliser application; reduced requirement for nitrogen fertiliser, and; helping farmers adapt to future climatic and elevated CO2 conditions. These outcomes will significantly improve and help protect the future financial and environmental conditions of rural Australia, and improve our national greenhouse account. Read moreRead less
Understanding plant residue decomposition by linking organic matter chemistry and soil microbiology. Soils are an important source or sink for CO2. Currently we lack a fundamental understanding of plant residue decomposition and their transformation into various soil organic carbon (SOC) pools. Since these different pools of soil C are recycled back to atmosphere at different rates, a better understanding of the process is crucial for our ability to manage soil C and to predict the impact of man ....Understanding plant residue decomposition by linking organic matter chemistry and soil microbiology. Soils are an important source or sink for CO2. Currently we lack a fundamental understanding of plant residue decomposition and their transformation into various soil organic carbon (SOC) pools. Since these different pools of soil C are recycled back to atmosphere at different rates, a better understanding of the process is crucial for our ability to manage soil C and to predict the impact of management on SOC. For the first time we will combine detailed chemical analyses of soil organic matter fractions with determination of decomposition rates and microbial community structure; thereby also increasing the knowledge of how Australia's biodiversity is modulated. Read moreRead less
Role of organic matter in soil pH change in agro-ecosystems. Over 50 million hectares of arable lands in Australia are affected by soil acidity. Acidity-affected lands continue to expand due to the ongoing process of acidification under current farming practices. The project will provide new knowledge essential for the improved use and management of organic matter to minimize or reverse soil acidification and increase carbon sequestration in farming systems. The associated reduction of soil aci ....Role of organic matter in soil pH change in agro-ecosystems. Over 50 million hectares of arable lands in Australia are affected by soil acidity. Acidity-affected lands continue to expand due to the ongoing process of acidification under current farming practices. The project will provide new knowledge essential for the improved use and management of organic matter to minimize or reverse soil acidification and increase carbon sequestration in farming systems. The associated reduction of soil acidification will also minimise the negative impact of nutrient and water losses on the environment. Growers will benefit from the project through improved soil fertility and crop production, and sustainable land use. Read moreRead less
The nature and ecological functions of soil soluble organic nitrogen in contrasting forest ecosystems. This project employs a series of innovative techniques to investigate the dynamic nature and ecological significance of soil soluble organic nitrogen - one of the important nutrient pools, in contrasting tropical, subtropical and temperate forest ecosystems. The successful conduct of this project will lead to: a) better fertilization recommendation schemes, reduced ecosystem N losses, improved ....The nature and ecological functions of soil soluble organic nitrogen in contrasting forest ecosystems. This project employs a series of innovative techniques to investigate the dynamic nature and ecological significance of soil soluble organic nitrogen - one of the important nutrient pools, in contrasting tropical, subtropical and temperate forest ecosystems. The successful conduct of this project will lead to: a) better fertilization recommendation schemes, reduced ecosystem N losses, improved forest productivity and sustainability, minimised environmental pollution and improved water quality in forested watersheds; b) effective conservation of biodiversity in both managed and natural forests; and c) enhanced international cooperation and reputation of the Australian scientists in the relevant research fields.Read moreRead less