Projects Available Now!
The following Honours projects are available now. If you are interested, or have questions regarding the projects, please contact Associate Professor Terry Rose (Phone: 0457 249 302)
Title: Predicting phosphorus bioavailability in biochars
Biochars are becoming an increasingly popular soil amendment, but at present there is no chemical test that can reliably predict the bioavailability of phosphorus in the char. Such a test would be beneficial because it would enable farmers to tailor the rates of biochar applied, or reduce rates of other phosphate amendments accordingly. The project will assess a range of extractants typically used to estimate bioavailability of phosphorus in fertilisers (citric acid, formic acid) or in soils (Colwell or Bray tests), and will relate these results to plant growth and phosphorus uptake when biochars are applied to soil as an ameliorant. The project thus has a combination of laboratory work and glasshouse work and suits students interested in agronomy, soils or plant nutrition.
Title: Why don’t nitrification inhibitors on nitrogen fertilisers perform in some soils?
Because nitrate leaches rapidly in many soils under persistent rainfall, many urea-based fertilisers now come with a nitrification inhibitor embedded in the fertiliser product. The inhibitor slows the conversion of ammonium to nitrate in soils, and because ammonium is a cation, it tends to remain in the topsoil where plants can access it (soils have a cation exchange capacity) as opposed to the nitrate anion which leaches. However, field trials suggest that in these products are relatively ineffective on our local soils and in our warm climate. We suspect that our soils are highly microbially active and we hypothesise that in the warm wet condition of the subtropics, soil microbes degrade the nitrification inhibitor rapidly – hence it doesn’t get the chane to inhibit nitrification. This project will use a series of laboratory incubation studies to test the hypothesis that soil microbial activity in our soils is limiting the effectiveness of nitrification inhibitors on fertilisers.
Title: Can the use of wastewater precipitation products solve the phosphorous deficit in Australian organic farming systems? (Honours/Masters)
Low availability of soil phosphorus is limiting organic grain production in Australia. Consequently, development of the organic food sector is being held back by a shortage of organic grain that is needed in almost every corner of the sector. Organic growers cannot use superphosphate to supply phosphorous for their crops, but they may use rock or soft phosphate, or compost with elevated phosphorus levels. A possible alternative for organic farmers might be the use of wastewater precipitation products such as struvite or calcium phosphate. Struvite is a slow release phosphorus and magnesium fertiliser that is produced from the decant water of anaerobic digestion facilities processing wastewater from municipal, food processing or intensive animal industry sources.
The project will seek to clarify whether and under which conditions particular sources of phosphorus derived from wastewater, such as struvite or calcium phosphate, can be allowed as inputs in certified organic farming systems in Australia. Results of the study, which will include a cost benefit assessment of using wastewater precipitation products and rock phosphate, will be presented in a discussion paper. The paper will be published on the Organic Trust Australia website and be also sent to Australian organic farming organisations.
Title: Determining the status of on-farm composting in New South Wales (Honours/Masters)
A considerable number of farmers in New South Wales compost organic residues from on- and off-farm sources, with some farmers possibly breaching current regulations. However, the extent of on-farm composting is unknown, as is the extent to which farmers might breach current regulatory requirements. Consequently, this project seeks to (i) establish the extent of on-farm composting in New South Wales, (ii) gauge knowledge among farmers that compost about regulatory requirements and their contravention and (iii) examine possibilities of improving New South Wales regulatory guidelines that govern this activity.
The status of on-farm composting in New South Wales and regulatory knowledge among farmers will be determined by means of electronic surveys and telephone interviews. The assessment of regulatory regimes governing on-farm composting activities in other Australian States and overseas (US, UK, Austria, Switzerland) will be used to identify options for improving current regulations in New South Wales.
This project will be carried out in collaboration with the NSW Farmers Federation and the Department of Primary Industries (both to be confirmed).