Strategies to reduce nitrous oxide emissions from nitrogen fertiliser applied to dryland sorghum. Part 2. Nitrous oxide emissions - Tamworth
2014 - 2015
Important note
The information contained in this publication is based on knowledge and understanding at the time of writing (July 2016). However, because of advances in knowledge, users are reminded of the need to ensure that the information upon which they rely is up to date and to check the currency of the information with the appropriate officer of NSW Department of Industry, Skills and Regional Development or the user’s independent adviser. The product trade names in this publication are supplied on the understanding that no preference between equivalent products is intended and that the inclusion of a product name does not imply endorsement by the department over any equivalent product from another manufacturer. Recognising that some of the information in this document is provided by third parties, the State of New South Wales, the author and the publisher take no responsibility for the accuracy, currency, reliability and correctness of any information included in the document provided by third parties.
To report on the nitrous oxide (N2O) emission results from the 2014–15 grain sorghum trials, which aimed to optimise both nitrogen (N) rate and fertiliser N release to benefit crop production and reduce N2O emissions.
Key messages
Fertiliser nitrogen (N) rates tailored to suit paddock history/ soil mineral N levels optimised N2O emissions.
At Tamworth, withholding N fertiliser on a high mineral N soil reduced N2O emissions, but did not optimise grain yield.
At Breeza, most strategies of urea + nitrification inhibitor, polymer-coated urea and split N application substantially reduced N2O emissions. Most alternatives produced similar grain yields to the current practice of urea all applied at sowing, so the N2O emissions intensity per tonne of grain produced was also reduced.
A 1:3 blend of urea + polymer-coated urea all applied at sowing, increased N2O emissions compared with the urea all at sowing treatment. The treatment also reduced grain yield, so potential slow-release treatments need to be carefully evaluated from both an N2O emissions and grain production point of view.
Lead research organisation
Department of Primary Industries NSW
Host research organisation
N/A
Trial funding source
GRDC DAN00129
Related program
NANORP Filling the Research Gap
Acknowledgments
This research was funded by NSW DPI and the Australian Government Department of Agriculture as part of the project DAN00129: NANORP Filling the Research Gap. Many thanks to Helen Squires, Mandy Holland, and Peter Sanson for assistance with field sampling and measurements, and the Tamworth cereal agronomy team for assistance with crop agronomy. Thanks also to Incitec Pivot Fertilisers Ltd for supplying Entec®, NV®, and the polymer-coated urea (not currently a commercial product).
Trial results Grain yield and cumulative N2O emissions summary at Tamworth
#
Treatment 1
Grain yield (t/ha)
Nitrous oxide emissions (g N2O/ha)
Nitrous oxide emission factor (%)
Emissions intensity (g N2O/t grain)
Emissions reduction (%)
1
█
sorg_0_N
7
87
-
13
72
2
█
sorg_+N
10.3
309
0.19
30
-
3
█
soy_0_n
8.3
208
-
25
33
4
█
soy_+N
10.2
215
0.02
21
30
5
█
sorg_split
11.6
-
-
-
-
Grain yield t/ha
Emissions intensity g N2O/t grain
Emissions reduction %
Nitrous oxide emission factor %
Nitrous oxide emissions g N2O/ha
Trial results Grain yield and cumulative N2O emissions summary at Breeza
#
Treatment 1
Grain yield (t/ha)
Nitrous oxide emissions (g N2O/ha)
Nitrous oxide emission factor (%)
Emissions intensity (g N2O/t grain)
Emissions reduction (%)
1
█
Treatment no. 1
5.2
133
-
24
79
2
█
Treatment no. 2
7.1
637
0.56
90
-
3
█
Treatment no. 3
6.6
228
0.11
35
64
4
█
Treatment no. 4
7.1
465
0.37
67
27
5
█
Treatment no. 5
6.6
220
0.1
32
66
6
█
Treatment no. 6
6.1
915
0.87
163
-44
7
█
Treatment no. 7
6.9
278
0.16
40
56
8
█
Treatment no. 8
6.7
344
0.23
52
46
9
█
Treatment no. 9
5.8
207
0.08
38
68
10
█
Treatment no. 10
6.8
214
0.09
31
67
11
█
Treatment no. 11
6.8
311
0.2
46
51
12
█
Treatment no. 11
6.7
208
0.08
31
67
13
█
Treatment no. 13
6.9
230
0.11
33
64
Grain yield t/ha
Emissions intensity g N2O/t grain
Emissions reduction %
Nitrous oxide emission factor %
Nitrous oxide emissions g N2O/ha
Climate
Derived climate information
No observed climate data available for this trial. Derived climate data is
determined from trial site location and national weather sources.
Breeza NSW
Tamworth Agricultural Institute NSW
Breeza NSW
NOTE: Exact trial site locality unknown - Climate data may not be accurate
Tamworth Agricultural Institute NSW
SILO weather estimates sourced from https://www.longpaddock.qld.gov.au/silo/
Jeffrey, S.J., Carter, J.O., Moodie, K.B. and Beswick, A.R. (2001). Using spatial interpolation to
construct a comprehensive archive of Australian climate data , Environmental Modelling and Software, Vol
16/4, pp 309-330. DOI: 10.1016/S1364-8152(01)00008-1.
