Hybrid brown coal-urea fertiliser reduces nitrogen loss compared to urea alone

Biplob K Saha; Michael T Rose; Vanessa Wong; Timothy R Cavagnaro; Antonio F Patti

doi:10.1016/j.scitotenv.2017.05.270

Hybrid brown coal-urea fertiliser reduces nitrogen loss compared to urea alone

Sci Total Environ. 2017 Dec 1:601-602:1496-1504. doi: 10.1016/j.scitotenv.2017.05.270. Epub 2017 Jun 9.

Authors

Biplob K Saha¹, Michael T Rose², Vanessa Wong³, Timothy R Cavagnaro⁴, Antonio F Patti⁵

Affiliations

¹ School of Chemistry, Monash University, Clayton, Victoria 3800, Australia; Department of Agricultural Chemistry, Bangladesh Agricultural University, Mymensingh 2202, Bangladesh.
² NSW Department of Primary Industries, Wollongbar Primary Industries Institute, Wollongbar, NSW 2477, Australia.
³ School of Earth, Atmosphere & Environment, Monash University, Clayton, Victoria 3800, Australia.
⁴ The Waite Research Institute and The School of Agriculture, Food and Wine, The University of Adelaide, Waite Campus, PMBI, Glen Osmonds, South Australia 5064, Australia.
⁵ School of Chemistry, Monash University, Clayton, Victoria 3800, Australia. Electronic address: tony.patti@monash.edu.

PMID: 28605867
DOI: 10.1016/j.scitotenv.2017.05.270

Abstract

Synthetic nitrogen (N) fertilisers, such as urea, are susceptible to rapid dissipation from soil. More gradual release of mineral N from fertiliser may reduce the off-site movement of mineral N, thereby enhancing N supply to crops and minimising negative off-site impacts. We hypothesised that granulation of urea with humified brown coal (BC) delays mineral N release and maintains higher concentrations of N in soil than conventional urea granules. Four different brown coal-urea granules, with C:N ratios of 1-10, were prepared by pan granulation. Advanced spectroscopic and X-ray powder diffraction (XRD) techniques confirmed loading of urea-N into the BC structure. Nitrogen-release from BCU granules was slower than from urea, resulting in higher N retention over a longer period for increasing growth and N uptake by crop plants. This trend increased with higher loading of BC, emphasising the significant role of BC in N retention. These findings support the hypothesis that BC is suitable for developing slow release N fertilisers.

Keywords: Brown coal; Fertiliser N use efficiency; Pan granulation; Slow release fertiliser; Urea.