Conserving soil moisture; does stubble or a fallow help on sandy soil?

2012
CC BY 4.0

Research organisaton
Funding source

Trial details

Researcher(s) Yvette Oliver (CSIRO) and Nadine Hollamby (Liebe Group)
Year(s) 2012
Contributor Liebe Group
Trial location(s) Site 4, East Wubin, WA
Conserving soil moisture; does stubble or a fallow help on sandy soil? locations
Aims

To determine if various farm management techniques improve the storage of out-of-season rainfall and whether this leads to improvements in yield.

Key messages
  • This is the second season in which this trial has been run and the fallow has yielded higher than continuous cropping in both 2011 (0.4 t/ha) and 2012 (0.2 t/ha). Other research indicates that fallows produce yield benefits in dry seasons which are not the case in the crop in 2011, which received 231mm for the growing season. The yield difference in 2011 was therefore more likely to have been the result of extra nitrogen in the soil, or weed or disease control rather than soil water benefits, however, these were not measured.
  • Farm economics need to be carefully considered before implementing a fallow, the opportunity cost of not producing a crop needs to be weighed up, and benefits of yield, extra N, weed control and disease breaks carefully factored into the decision. 
  • In 2012 the yield benefit from fallow was 0.2 t/ha and likely to be due to extra nitrogen and water being present in the soil. However, this is an unreplicated demonstration and thus it is hard to tell whether yield differences are the result of fallow or random variation in the paddock. 
Lead research organisation N/A
Host research organisation N/A
Trial funding source GRDC LIE00006
Related program N/A
Acknowledgments

GRDC for funding the trial and Keith Carter & Co for hosting the trial.


Other trial partners Not specified
Download the trial report to view additional trial information

Method

Crop type Wheat
Treatment type(s)
  • Stubble: Management
Trial type Demonstration
Trial design Unreplicated

East Wubin 2012

Sow rate or Target density 40
Sow date 10 May 2012
Harvest date Not specified
Plot size 300m x 15m
Plot replication 1
Paddock history 2009 pasture, 2010 wheat, 2011 wheat
Fertiliser

10/5/12: 70 kg/ha K-Till Extra, 50 L/ha Flexi-N banded,

23/7/12: 20 L/ha Flexi-N

Herbicide

3/2/12: 1.2 L/ha Glyphosate, 0.5 L/ha Ester 800, 0.15 L/ha Garlon,

4/5/12: 120 g/ha Sakura, 0.1 L/ha Ester 800, 1.5 L/ha Roundup,

13/8/12: 0.35 L/ha Paragon, 0.3 L/ha MCPA

Download the trial report to view additional method/treatment information

Download results

Trial results Table 1

# Treatment 1
Protein (%) Nearest neighbour control (%) Grain yield (t/ha) Hectolitre weight (kg/hL)
1 Continuous crop with standing stubble 12 100 1.1 79
2 Continuous crop with standing stubble 12 100 1.2 82
3 Fallow 12 116 1.4 80
4 Flattened stubble 13 92 1.1 79
5 Old fallow 13 100 1.1 82

Grain yield t/ha


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Hectolitre weight kg/hL


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Nearest neighbour control %


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Protein %


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Observed trial site soil information
Trial site soil testing
Site Depth Type pH EC P K N A OC CAT
Site 4, East Wubin, WA 0 - 10cm Sand over Gravel 5.20
Site 4, East Wubin, WA 10 - 30cm Sand over Gravel 4.80
Soil conditions
Trial site Soil texture
Site 4, East Wubin, WA Sand over gravel
Derived trial site soil information
Australian Soil Classification Source: ASRIS
Trial site Soil order
Site 4, East Wubin, WA Kandosol
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 Site 4, East Wubin WA
2012 278.4mm
2011 258.9mm
2010 223.5mm
2009 260.4mm
2008 309.1mm
2007 251.1mm
2006 278.5mm
2005 257.4mm
2004 240.0mm
2003 264.7mm
2002 202.2mm
2001 235.4mm
2000 328.2mm
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

Site 4, East Wubin WA 2012


Observed climate information

Rainfall trial gsr (mm) 145mm

Derived climate information

Site 4, East Wubin WA

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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.