Determining nitrogen cycling dynamics in semi-arid soil


Research organisatons
Funding source

Trial details

Researcher(s) Louise Barton
Louise Fisk
Deirdre Gleeson
Linda Maccarone
Daniel Murphy
Yoshi Sawada
Year(s) 2012
Contributor SoilsWest
Trial location(s) Buntine, WA
Related trials
Determining nitrogen cycling dynamics in semi-arid soil locations

To determine the soil depth that microbes responsible for nitrification (conversion of ammonium to nitrate) are located. 

Key messages

Nitrifying archaea and bacteria live at different soil depths, with nitrifying bacteria inhabiting the surface soil and nitrifying archaeal populations inhabiting the sub-soil (10-90 cm). Nitrifying bacteria are the most numerous overall when compared to the nitrifying archaea, and their decline in abundance with soil depth matches the decline in soil nitrification rates. In these soils, nitrification rates are low, suggesting the amount of NH4+ is low, leaving little available for nitrification. Understanding the ecology of these microbes and their role in soil nitrification rates, may lead to improved management strategies to decrease N losses from the soil and improve N use efficiency. 

Lead research organisation University of Western Australia
Host research organisation Liebe Group
Trial funding source GRDC UWA00139
Related program Soil Biology Initiative

The authors would like to thank all members of the Soil Biology group who helped with sampling and soil analysis and would also like to thank the Liebe Group for allowing us to use their long term field site at Buntine. This research was funded by the GRDC as part of the Soil Biology Initiative II. 

Other trial partners DAFWA


Crop type None: No crop specified
Treatment type(s)
  • Soil Improvement: Application Method
  • Soil Improvement: Type
Trial type Experimental
Trial design Replicated,Blocked

Buntine 2012

Sow rate or Target density NA
Sowing machinery

Sampled out of season.

Sow date Not specified
Harvest date Not specified
Plot size 11m x 80m
Plot replication 3

Sampled out of season.

Soil amelioration

Field organic matter treatments: tilled soil, tilled soil loaded with organic! matter at 20 t/ha every  three years since 2003. 

Tillage Offset discs.
Trial source data and summary not available
Check the trial report PDF for trial results.
Observed trial site soil information
Trial site soil testing
Site Depth Type pH EC P K N A OC CAT
Buntine, WA 0 - 10cm Sand 6.60 29.00 98.00 18.00 0.81
Soil conditions
Trial site Soil texture
Buntine, WA Deep sand
Derived trial site soil information
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 Buntine WA
2012 114.9mm
2011 147.3mm
2010 115.2mm
2009 127.0mm
2008 144.9mm
2007 100.2mm
2006 104.1mm
2005 130.1mm
2004 125.2mm
2003 130.9mm
2002 87.6mm
2001 67.7mm
2000 105.5mm
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



Buntine WA 2012

Observed climate information

Rainfall trial gsr (mm) 162.5mm

Derived climate information

Buntine WA


Some data on this site is sourced from the Bureau of Meteorology

SILO weather estimates sourced from
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

No trial reports or attachments found

Trial last modified: 22-05-2019 11:11am AEST