Graeme Schwenke
Soil Scientist at DPI’s Tamworth Agricultural Institute, Dr Graeme Schwenke (above) will lead a research project to investigate options for mitigating nitrous oxide emissions from cropping soils in North-West NSW. The project will receive $400,000 in funding from GRDC. Use of fertiliser N in the agricultural sector accounts for 32% of N2O emissions or 5.2 Mt CO2-e per year. Of the 1 million tonnes of fertiliser N used annually in this sector, approximately 70% is applied to cereals. Graeme’s project proposes to mitigate emissions in cereal production systems of the North-West slopes and plains, through (i) partial substitution of fertiliser N inputs with biologically-fixed legume N, (ii) increasing nitrogen use efficiency (NUE) through strategic location of crop rows in relation to N fertiliser and prior crop residues using precision guidance technology, and (iii) modelling and development of effective extension packages for farmers. We also aim to develop real-world multiplier factors to replace IPCC default values used in calculating GHG emissions from fertiliser and legume use.
The experimental strategies will result in reduced inputs of fertiliser N, with direct consequences for both on-farm and off-farm emissions, as well as economic benefits for farmers through reduced input costs and more efficient production systems. The cost of fertiliser N to farmers more than doubled in 2008. Graeme aims to model project outcomes and develop effective management tools that farmers can use at the paddock level to mitigate their emissions whilst maintaining farm productivity.