Commercial/proprietary research projects
- Fertiliser formulation involving coating technology for better delivery of micronutrients
- Isotopic (radioactive and stable) and spectroscopic evaluations of macro- and micronutrient
- Phosphorus and sulfur nutrition
- Potash fertilisers
- Agronomy field trials
Fertiliser use efficiency in dryland cropping
A range of stable and radioisotopic methods are being used to investigate dissolution, diffusion, availability, and reaction products of phosphorus and micronutrient fertilisers in soils. These techniques are complementary and are being used to obtain a clear picture of how P and micronutrient fertilisers behave in different soils subjected to different soil water potentials and variations in potential (e.g. wetting and drying cycles), and their influence on plant nutrient uptake.
Developing chemical methods to mobilise fixed nutrients in cropping soils
This project aims to increase the efficiency of use of applied fertiliser P, through improving crop access to soil P reserves, or minimising the fixation of added fertiliser nutrients. Success in achieving this outcome will be measured by the ability of crops to access a larger amont of accumulated soil P reserves, thus reducing the need for fertiliser inputs,or improvements in crop acquisition of added fertiliser P.
Improving nitrogen and phosphorus management in south-east Australian cropping systems
This project aims to increase the economic effectiveness of nutrient inputs in cropping systems of south-eastern Australia by developing an improved understanding of key factors (abiotic and biotic) regulating the supply and utilisation of nitrogen and phosphorus by crops. This information will provide the foundation for better predictions of fertiliser requirements as well as contributing to the development of management strategies designed to increase the efficiency with which nutrients are used in cropping systems.
Phosphorus reactions and fluxes in pasture soils
The phosphorus fertiliser use efficiency of Australian pastures is unpredictable and invariably low. A large proportion of fertiliser phosphorus can be incorporated into the organic phosphorus pool, where it is transformed into more thermodynamically stable compounds i.e., less plant available. Surprisingly, there is little known on the mechanisms that govern organic phosphorus sequestration. This information will be used to manipulate the chemical reactions involved in organic phosphorus accumulation and release, and will lead to techniques that increase phosphorus fertiliser use efficiency in Australian pastures.
Development and validation of new soil testing methods
A more accurate measurement of soil plant available nutrients will facilitate better fertiliser decisions and nutrient management strategies. This project aims to assess the performance of established soil testing methods for potassium and sulphur together with emerging tests i.e., Diffusive gradient in thin films (DGT) to measure available potassium and sulphur. This works follows from the validation of DGT for phosphorus under field conditions. The DGT method for phosphorus is now commercially available in Australian soil testing laboratories.
To further validate the performance of DGT method for phosphorus and accurately predict fertiliser phosphorus requirements, ongoing research is investigating at the effect of phosphorus buffering index (PBI) on the increase in DGT values with P fertilisation under deficient scenarios. In this project, the ability of mid infrared spectroscopy (MIR) to predict the PBI of soils in the laboratory and the field is also being investigated. More targeted P fertiliser programs could occur with increased knowledge of paddock variability in terms of P sorption and fixation.
X-ray fluorescence (XRF) has shown promise as a cheap alternative tool to inductively coupled plasma emission spectroscopy (ICP) for measuring total nutrient contents in plant matter. This project aims to expand the calibration sets of XRF vs. ICP for different crop types. As XRF is now available as a hand held unit, the ability of XRF to measure plant nutrient concentrations insitu will also be assessed.
Tactical foliar phosphorus fertilisation
This project aims to investigate the potential benefits of foliar phosphorus fertiliser to increase grain yield and phosphorus use efficiency in wheat crops in the Southern Cropping Region. As the cost of phosphorus increases so does the economic risk of addition of starter phosphorus in regions with seasonally variable climate. Since the crop demand for phosphorus varies with in-season rainfall, we are investigating the potential benefits of "topping up" phosphorus nutrition using in-season applications of foliar applied phosphorus. Tactically applied foliar phosphorus would allow significant reductions in the amount of phosphorus added at sowing in areas where phosphorus is marginally limiting. Our approach includes laboratory, glasshouse and field based experiments including use of radiolabelled and non-radiolabelled foliar fertilisers to determine the potential and effectiveness of different formulations and investigate some of the factors that influence the effectiveness of foliar application.
Slow-release boron fertilisers
This project aims to investigate the synthesis and characterization of co-granulated boron fertiliser sources with macronutrients as a potential new slow-release boron fertiliser for high rainfall environments.
PhD and Honours students interested in any of the research projects described below can contact us directly.
Slow release sulfur fertilisers
Sulfate is plant available but can be readily leached in high rainfall environments. Elemental S is a slow release form of S but the extent and rate of release require further research. We are currently using stable and radioisotope labelling to trace S behaviour in soil-plant systems. Opportunities exist to look at interactions between S oxidation and microbial activities in Australian soils.
Phosphate efficiency is limited by sorption and fixation reactions in soils. A joint project between GRDC and The Mosaic Company is currently examining chemical methods to improve P efficiency in cropping systems. Opportunities exist for organic chemistry graduates to identify and/or synthesise candidate compounds which could improve the efficiency of fertiliser P use.
Previous research has shown huge benefits of fertilising infertile subsoils. The limitation has always been that there is no suitable method to apply fertiliser to subsoils. Opportunities exist to modify nutrient release and transport so that topsoil placement can also increase the fertility of subsoils in dryland agriculture.
Opportunities exist to apply new isotopic tracing techniques (e.g. natural abundance isotopic ratios) to trace fertiliser nutrient behaviour and crop uptake in agriculture systems. Advances in synchrotron-based techniques are also opening up new opportunities to study localisation and speciation of nutrients in fertilisers, plants and soils.
Slow release technologies are more effective formulations for crop growth and biofortification. Opportunities exist for projects examining the following elements; Zn, Mn, Cu, Fe, B, Mo, Se, etc.
Nanofertilisers and Biostimulant fertilisers
Opportunities exist for research to investigate the potential of nanofertilisers and biostimulant fertilisers to improve nutrient use efficiency.