Nitrogen cycling in cereal stubble retained systems

2014 - 2015

Research organisatons
Funding sources

Trial details

Researcher(s) Claire Browne
Bill Davoren
Vadakattu Gupta
John Kirkegaard
Stasia Kroker
Rick Llewellyn
Therese McBeath
Alan Richardson
Jonathan Sanderman
Steve Szarvas
Year(s) 2014 - 2015
Contributor Mallee Sustainable Farming Inc.
Trial location(s) Temora, NSW
Karoonda, SA
Horsham, VIC
Nitrogen cycling in cereal stubble retained systems locations
Aims

To strengthen our knowledge on seasonal changes in the (1) biological value of stubble (2) mineralisation: immobilisation balance (ratio) and (3) the direct supply of N from stubble to crops as influenced by stubble management.

Key messages
  • The 2014 wheat crop at Karoonda had a harvest index of 0.4 and fertilizer N recovery was 35%.
  • Wheat stubble from the 2014 crop contained 16 kg N/ha and had a C:N ratio of 95 which is common for cereal crop residues in these environments .
  • Mineralization during summer resulted in the accumulation of 18-33 kg/ha of mineral N to 50cm depth across all the treatments at sowing in 2015.
  • Incorporation of 2014 cereal stubble increased microbial biomass and N supply potential at sowing in the surface soil when compared with standing stubble.
  • The management of cereal stubble affects the microbial activity that influences the cycling and supply of nutrients (nitrogen (N) and phosphorus) to growing crops.
  • There was no significant effect of management of 2014 stubble on subsequent wheat grain yield in 2015.
Lead research organisation Commonwealth Scientific and Industrial Research Organisation
Host research organisation N/A
Trial funding source GRDC MSF00003
Trial funding source CSIRO CSIRO Agriculture
Related program Maintaining profitable farming systems with retained stubble
Acknowledgments

Funding for this work was from the Stubble Retention initiative and GRDC projects CSP00186, MSF00003, CSP00138 and CSIRO Agriculture. Thanks to the Loller family (Karoonda) for their generous support in hosting the trials. The contributions from the extended research teams at CSIRO are also gratefully acknowledged.


Other trial partners Peer review by Margaret Roper (CSIRO)
Download the trial report to view additional trial information

Method

Crop type Cereal (Grain): Wheat
Treatment type(s)
  • Fertiliser: Timing
  • Fertiliser: Type
Trial type Experimental
Trial design Replicated

Temora 2014

Sow date Not specified
Harvest date Not specified
Plot size Not specified
Plot replication Not specified
Fertiliser Not specified
Other trial notes

During the 2014 crop season wheat was fertilized with 15N isotope labelled Urea applied in two doses (i.e. 2 weeks after sowing and at GS 32) @ 70 kg N/ha. Similar experiments were set up at Horsham, Vic and Temora, NSW (@ 100 kg N / ha). Labelling stubble with 15N helps directly trace the transfer of N from wheat stubble into soil organic matter and to the crop in 2015. Following the harvest of 2014 wheat crop, replicated stubble retention treatment plots representing nil (stubble cut low and removed), surface (stubble cut low and retained), standing (stubble cut at standard height and retained) and incorporated (cultivation to 10cm depth following harvest) stubble were established on 2014 wheat crop plots adjacent to the 15N labelled area. A uniform mixture of 15N labelled stubble and chaff samples was prepared using the 15N residue collected after the 2014 crop harvest, e.g. stubble cut to 5-10cm length pieces, and applied in microplots (~2 sq M plots) in the ‘Inc

Temora 2015

Sow date Not specified
Harvest date Not specified
Plot size Not specified
Plot replication Not specified
Fertiliser Not specified
Other trial notes

During the 2014 crop season wheat was fertilized with 15N isotope labelled Urea applied in two doses (i.e. 2 weeks after sowing and at GS 32) @ 70 kg N/ha. Similar experiments were set up at Horsham, Vic and Temora, NSW (@ 100 kg N / ha). Labelling stubble with 15N helps directly trace the transfer of N from wheat stubble into soil organic matter and to the crop in 2015. Following the harvest of 2014 wheat crop, replicated stubble retention treatment plots representing nil (stubble cut low and removed), surface (stubble cut low and retained), standing (stubble cut at standard height and retained) and incorporated (cultivation to 10cm depth following harvest) stubble were established on 2014 wheat crop plots adjacent to the 15N labelled area. A uniform mixture of 15N labelled stubble and chaff samples was prepared using the 15N residue collected after the 2014 crop harvest, e.g. stubble cut to 5-10cm length pieces, and applied in microplots (~2 sq M plots) in the ‘Inc

Karoonda 2014

Sow date Not specified
Harvest date Not specified
Plot size Not specified
Plot replication Not specified
Fertiliser Not specified
Other trial notes

During the 2014 crop season wheat was fertilized with 15N isotope labelled Urea applied in two doses (i.e. 2 weeks after sowing and at GS 32) @ 70 kg N/ha. Similar experiments were set up at Horsham, Vic and Temora, NSW (@ 100 kg N / ha). Labelling stubble with 15N helps directly trace the transfer of N from wheat stubble into soil organic matter and to the crop in 2015. Following the harvest of 2014 wheat crop, replicated stubble retention treatment plots representing nil (stubble cut low and removed), surface (stubble cut low and retained), standing (stubble cut at standard height and retained) and incorporated (cultivation to 10cm depth following harvest) stubble were established on 2014 wheat crop plots adjacent to the 15N labelled area. A uniform mixture of 15N labelled stubble and chaff samples was prepared using the 15N residue collected after the 2014 crop harvest, e.g. stubble cut to 5-10cm length pieces, and applied in microplots (~2 sq M plots) in the ‘Inc

Karoonda 2015

Sow date 21 May 2015
Harvest date Unknown
Plot size Not specified
Plot replication Not specified
Fertiliser

DAP @ 50 kg/ha and Urea @ 24kg/ha

Other trial notes

During the 2014 crop season wheat was fertilized with 15N isotope labelled Urea applied in two doses (i.e. 2 weeks after sowing and at GS 32) @ 70 kg N/ha. Similar experiments were set up at Horsham, Vic and Temora, NSW (@ 100 kg N / ha). Labelling stubble with 15N helps directly trace the transfer of N from wheat stubble into soil organic matter and to the crop in 2015. Following the harvest of 2014 wheat crop, replicated stubble retention treatment plots representing nil (stubble cut low and removed), surface (stubble cut low and retained), standing (stubble cut at standard height and retained) and incorporated (cultivation to 10cm depth following harvest) stubble were established on 2014 wheat crop plots adjacent to the 15N labelled area. A uniform mixture of 15N labelled stubble and chaff samples was prepared using the 15N residue collected after the 2014 crop harvest, e.g. stubble cut to 5-10cm length pieces, and applied in microplots (~2 sq M plots) in the ‘Inc

Horsham 2014

Sow date Not specified
Harvest date Not specified
Plot size Not specified
Plot replication Not specified
Fertiliser Not specified
Other trial notes

During the 2014 crop season wheat was fertilized with 15N isotope labelled Urea applied in two doses (i.e. 2 weeks after sowing and at GS 32) @ 70 kg N/ha. Similar experiments were set up at Horsham, Vic and Temora, NSW (@ 100 kg N / ha). Labelling stubble with 15N helps directly trace the transfer of N from wheat stubble into soil organic matter and to the crop in 2015. Following the harvest of 2014 wheat crop, replicated stubble retention treatment plots representing nil (stubble cut low and removed), surface (stubble cut low and retained), standing (stubble cut at standard height and retained) and incorporated (cultivation to 10cm depth following harvest) stubble were established on 2014 wheat crop plots adjacent to the 15N labelled area. A uniform mixture of 15N labelled stubble and chaff samples was prepared using the 15N residue collected after the 2014 crop harvest, e.g. stubble cut to 5-10cm length pieces, and applied in microplots (~2 sq M plots) in the ‘Inc

Horsham 2015

Sow date Not specified
Harvest date Not specified
Plot size Not specified
Plot replication Not specified
Fertiliser Not specified
Other trial notes

During the 2014 crop season wheat was fertilized with 15N isotope labelled Urea applied in two doses (i.e. 2 weeks after sowing and at GS 32) @ 70 kg N/ha. Similar experiments were set up at Horsham, Vic and Temora, NSW (@ 100 kg N / ha). Labelling stubble with 15N helps directly trace the transfer of N from wheat stubble into soil organic matter and to the crop in 2015. Following the harvest of 2014 wheat crop, replicated stubble retention treatment plots representing nil (stubble cut low and removed), surface (stubble cut low and retained), standing (stubble cut at standard height and retained) and incorporated (cultivation to 10cm depth following harvest) stubble were established on 2014 wheat crop plots adjacent to the 15N labelled area. A uniform mixture of 15N labelled stubble and chaff samples was prepared using the 15N residue collected after the 2014 crop harvest, e.g. stubble cut to 5-10cm length pieces, and applied in microplots (~2 sq M plots) in the ‘Inc

Download the trial report to view additional method/treatment information

Download results

Trial results Table 1

# Treatment 1
Grain yield (t/ha) Nitrogen uptake (kg N/ha) Harvest index (value) Stubble yield (t/ha)
1 Karoonda 2.51 66 0.41 3.31
2 Horsham 2.19 97 0.32 4.7
3 Temora 3.29 742 0.28 8.38

Grain yield t/ha


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Harvest index value


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Nitrogen uptake kg N/ha


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Stubble yield t/ha


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Observed trial site soil information
Trial site soil testing
Not specified
Soil conditions
Trial site Soil texture
Temora, NSW Not specified
Karoonda, SA Not specified
Horsham, VIC Not specified
Derived trial site soil information
Australian Soil Classification Source: ASRIS
Trial site Soil order
Temora, NSW Kandosol
Karoonda, SA Calcarosol
Horsham, VIC Vertosol
Soil Moisture Source: BOM/ANU
Average amount of water stored in the soil profile during the year, estimated by the OzWALD model-data fusion system.
Year Temora NSW Karoonda SA Horsham VIC
2015 580.1mm261.2mm844.6mm
2014 536.2mm252.1mm838.6mm
2013 552.2mm237.4mm843.8mm
2012 603.7mm295.6mm851.0mm
2011 615.3mm357.6mm856.7mm
2010 622.2mm309.7mm858.7mm
2009 570.3mm240.5mm850.1mm
2008 556.2mm226.5mm850.5mm
2007 475.6mm265.4mm851.7mm
2006 514.6mm275.1mm840.3mm
2005 516.7mm288.1mm852.1mm
2004 454.7mm252.3mm833.5mm
2003 422.3mm265.0mm795.2mm
2002 414.1mm222.9mm733.4mm
2001 454.0mm240.8mm712.5mm
2000 430.4mm304.2mm665.7mm
National soil grid Source: CSIRO/TERN
NOTE: National Soil Grid data is aggregated information for background information on the wider area
Actual soil values can vary significantly in a small area and the trial soil tests are the most relevant data where available

Soil properties

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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.

Temora VIC

Karoonda VIC

Horsham VIC

Temora VIC

NOTE: Exact trial site locality unknown - Climate data may not be accurate
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Karoonda VIC

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Horsham VIC

NOTE: Exact trial site locality unknown - Climate data may not be accurate
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Some data on this site is sourced from the Bureau of Meteorology

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.

Trial report and links

2015 trial report



Trial last modified: 14-01-2023 23:46pm AEST