PICCC Honorary Research Fellow: Karina Marsden

Dr Karina MarsdenIn collaboration with Bangor University, UK, the University of Melbourne’s Primary Industries Climate Challenges Centre successfully secured a prestigious Marie Sklodowska Curie Global Fellowship under the EU’s Horizon 2020 Programme.

The joint two year appointment brings post-doctoral researcher Dr Karina Marsden to the University’s More Profit from Nitrogen (MFfN) dairy team. She will apply her strengths in molecular ecology, stable isotope methods and whole-farm system analyses to the team’s current research capacity across the various MPfN dairy sites supervised by Prof Richard Eckard and Dr Helen Suter.

Karina completed her PhD thesis “Sheep urine patch nitrous oxide emissions: Measurement and mitigation.” at Bangor University under the supervision of Professor Dave Chadwick (co- collaborator on this fellowship). Her post-doctoral research on the Uplands-N2O project at Bangor, investigating nitrous oxide emissions from extensively grazed systems is a robust segue to this post-doctoral Fellowship work.

MPfN is a four-year research partnership between Australia’s four major intensive users of nitrogenous fertilisers (cotton, dairy, sugar and horticulture) which aims to increase nitrogen use efficiency of intensive cropping and pasture systems.

Nitrogen fertilisers are a significant input cost to farmers in each of these industries and a substantial contributor to agriculture’s environmental footprint, particularly the highly damaging greenhouse gas nitrous oxide (N2O).

Collectively, MPfN aims to increase farm profitability while reducing environmental impact by helping farmers to reduce of the amount of nitrogen required to produce each unit of produce.

During her Fellowship, Karina will contribute to Target-N2O: a project coordinated by Bangor University which aims to establish the potential use of the nitrification inhibitor, dimethylpyrazole phosphate (DMPP), in nitrous oxide mitigation strategies in intensive dairy farming to improve the efficiency. It has been established that concentrated areas of nitrous oxide emissions on farm (‘hot-spots’) emit large proportions of the total farm nitrous oxide emissions. For example, a recent study in New Zealand found that gateways contributed 9.4 per cent of total farm nitrous oxide emissions despite occupying only 3.2 per cent of the farm area.

Targeting these hotspots for nitrification inhibitor application over a relatively small area has economic significance as this may minimise product and labour costs, but factors controlling the effectiveness of DMPP to reduce nitrogen loss to the environment, and the relative agronomic efficacy of its use in such areas, remains unestablished.

Karina’s research will include microbiological techniques in soil nitrogen cycling, stable isotope methods to quantify nitrogen losses and farm system and nitrogen cycle modelling to determine cost-benefit analysis of targeted DMPP applications to case-study intensive dairy farms in both southern and northern hemispheres.