Baselining greenhouse gas emissions from Australian rice crops

Summary

It has been identified overseas that the adoption of potential water saving rice growing practices that reduce the period of crop inundation reduces greenhouse gas emissions and rice sourced global warming potential. However, there are no robust and accurate season long published baseline greenhouse gas datasets for Australian rice growing conditions for conventional, or newer drill sown growing practices that save water. Currently the rice industry is complying with national greenhouse gas accounting using emission factors that have been developed in south-east Asian countries which do not reflect the Australian temperate climate, water management or rice agronomy. The project will baseline methane and nitrous oxide emissions in commercial rice crops on-farm using established methods.

Ancillary data including meteorology, soil-plant-water, soil physical and chemical characteristics and plant development will also be collected. This proposal specifically requests funding for a capital item of an eddy co-variance tower equipped with methane sensor to collect long-term datasets of this potent greenhouse gas for new water saving rice growing practices that involve several wetting and drying events.

In combination with salary funding for a Deakin University post-doctoral early career researcher with expertise in rice agriculture and machine learning data informatics, this equipment will provide much needed locally based state of the art research capacity for the rice industry. Considering that maximum methane and nitrous oxide fluxes occur during event-related peaks, previous findings highlight the need to better characterize the short-term temporal variability of GHG emissions in rice systems, particularly during discrete field flushing and drainage events.

Capturing ongoing and event-related emissions will be undertaken during water transition periods and fertilizer application events using static chamber manual greenhouse gas measurement methods which will help ensure that accurate data are available to support scaling-up efforts and the development of regional and national GHG inventories.

Program

Rice

Research Organisation

Deakin University (a body politic and corporate established pursuant to the Deakin University Act 2009 (Vic))

Objective Summary

The objectives of the project are to baseline and determine the differences in methane, nitrous oxide and total global warming potential (CO2 equivalents) from rice crops grown in two different Riverina rice growing regions when different water management practices are used to grow high yielding commercial crops. The data will be communicated so that growers are informed about how their practices can mitigate greenhouse gases and understand the contribution this can make to maintaining the social license to grow rice in view of climate change. The data will also contribute to re-baselining country specific methane emission factors for rice for application to the national greenhouse gas inventory which may be important for international marketing of rice according to consumer sustainability preferences.