Addressing the nitrogen problem in sugarcane production to reduce pollution of the Great Barrier Reef

N Robinson 1, R Brackin1, C Paungfoo-Lonhienne1, T Lonhienne2, M Westermann1, M Salazar1, YK Yeoh3, P Hugenholtz3, MA Ragan4, M Redding5, C Pratt5, WJ Wang6, A Royle7, L DiBella7, P Lakshmanan8, S Schmidt1

1 School of Agriculture and Food Science, The University of Queensland, Brisbane QLD 4072, Australia

2 School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane QLD 4072, Australia

3Australian Centre for Ecogenomics, School of Chemistry and Molecular Biosciences, The University of Queensland

4 Institute for Molecular Bioscience, The University of Queensland, Australia

5 Department of Agriculture and Fisheries, 203 Tor Street, Toowoomba, Qld 4350, Australia.

6 Department of Science, Information Technology and Innovation, 41 Boggo Road, Dutton Park QLD 4102, Australia

7 Herbert Cane Productivity Services Limited, Ingham QLD 4850, Australia

8 Sugar Research Australia, Indooroopilly, QLD 4068, Australia


The N pollution footprint of sugarcane cropping is large due to inefficiencies caused by mismatched N supply and crop N demand over sugarcane’s long N accumulation phase. The Great Barrier Reef lagoon receives excessive N loads that contribute to the rapidly declining reef health. Exceeding international average nitrous oxide emission rates several fold, sugarcane soils contribute significantly to Australia’s agricultural emissions. Nitrogen pollution reduction schemes over recent decades have mostly targeted reducing N fertiliser rates in line with expected yields and improving soil quality. Overall, these measures have not resulted in the desired N pollution reduction and further innovation is needed to address this problem. We present research that aims to aid agronomic innovation with (i) next-generation fertilisers that are based on repurposed nutrient-rich wastes and sorbent materials to better match N supply and crop demand and to improve soil function and carbon levels, (ii) understanding of soil N cycling and microbial processes, (iii) legume companion cropping as a source of biologically fixed N, and (iv) genetic improvement of sugarcane that more effectively captures and uses N. We conclude that evidence-based innovation has to support crop growers across climate and soil gradients in the 400,000 hectares of catchments of the Great Barrier Reef. This should include investment into new technologies to support ecologically-sound agriculture and a circular economy without waste and pollution.