Impact of retaining stubble in low rainfall farming systems

2015

Research organisatons
Funding source

Trial details

Researcher(s) Amanda Cook, Wade Shepperd and Ian Ricther (SARDI)
Year(s) 2015
Contributor Eyre Peninsula Agricultural Research Foundation
Trial location(s) Site 16, Minnipa Agricultural Centre, SA
Related trials
Impact of retaining stubble in low rainfall farming systems locations
Aims

The GRDC project ‘Maintaining profitable farming systems with retained stubble - upper Eyre Peninsula’ aims to produce sustainable management guidelines to control pests, weeds and diseases while retaining stubble to maintain or improve soil health, and reduce exposure to wind erosion. The major outcome to be achieved is increased knowledge and skills allowing farmers and advisers to improve farm profitability while retaining stubble in farming systems on upper Eyre Peninsula (EP).

The Minnipa Agricultural Centre (MAC) S7 stubble retention trial was established to maintain or improve crop production through applying alternative weed, disease and pest control options in pasture wheat rotations in the presence of crop residues. The trial was established in 2013 with wheat and different stubble treatments imposed at harvest annually. It was sown either inter row or on row with wheat in 2014 and 2015 to determine the impacts of stubble management on crop production, weeds, disease and pests in low rainfall farming systems.

Key messages
  • There were no differences in wheat yield at Minnipa in response to stubble architecture, seeding position and nitrogen treatments in 2015.
  • In 2015 plant establishment was reduced with cultivation and the addition of nitrogen at seeding compared to standing stubble cut low at harvest. The extra nitrogen applied at seeding also reduced the early dry matter.
  • Removing and cutting stubble low decreased the Yellow Leaf Spot disease incidence and snail numbers compared to high cut stubble.
  • Stubble management and seeding position had little effect on grass weed numbers.
  • Overall at Minnipa, stubble management and seeding position have not impacted highly on crop production, weeds, disease and pests over two years with relatively high stubble loads in low rainfall farming systems.
Lead research organisation Eyre Peninsula Agricultural Research Foundation
Host research organisation SARDI Minnipa Agricultural Centre
Trial funding source GRDC EPF00001
Related program Maintaining profitable farming systems with retained stubble
Acknowledgments

Thank you to Sue Budarick for processing samples. Trial funded by GRDC Maintaining profitable farming systems with retained stubble - upper Eyre Peninsula (EPF00001).


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

Method

Crop type Cereal: Wheat
Treatment type(s)
  • Sowing
  • Stubble: Management
  • Stubble: Height
Trial type Experimental
Trial design Replicated
Sow rate or Target density 60kg/ha
Sowing machinery

Plot seeder

Sow date 12 May 2015
Harvest date 11 November 2015
Plot size 18m x 2m
Plot replication 3
Plot blocking Not specified
Plot randomisation Not specified
Paddock history 2015: Grenade wheat 2014: Grenade wheat 2013: Mace wheat
Fertiliser

DAP @ 60 kg/ha

All plots were split with urea being added to one half at 40 kg/ha applied at seeding. This rate was estimated to match estimated annual nitrogen tie up with the retained stubble loads. Since 5.8 kg N is required per tonne of stubble to break it down (Kirby et al. 2004), for 3.5 t/ha of wheat stubble approximately 20 kg N is required, or may have been tied up due to the stubble being present in the retained stubble treatments. An extra 20 kg/ha of urea was spread on all plots on 9 June 2015. The decision to add extra nitrogen as a split treatment was made after reviewing the 2014 season results

Herbicide

1.2 L/ha Roundup Attack and 2.5 L/ha Boxer Gold on 12 May. 750 ml/ha Tigrex and 100 ml/ha Lontrel on 23 July

Insecticide

Nil

Fungicide

Nil

Pesticide Not specified
Soil amelioration

Nil

Seed treatment Not specified
Inoculant Not specified
Tillage Not specified
Other trial notes Not specified
Download the trial report to view additional method/treatment information

Trial results Table 1

# Treatment 1
Protein (%) Test weight (kg/hL) Plant Establishment (plants/m2) Yellow leaf spot ((0-10)) Screenings (%) Yield (t/ha) Early dry matter (kg/m2) Late dry matter (kg/m2)
1 Stubble standing high 11.1 79.6 65 6 5.7 1.19 0.01 0.43
2 Stubble standing low 11 79.8 71 5.4 4.3 1.28 0.01 0.41
3 Stubble cultivated 10.1 80.2 45 5.4 5.2 1.26 0.01 0.42
4 Stubble removed 11 80.5 73 4.3 5 1.2 0.01 0.43
5 Inter row 10.9 80.2 65 5.1 4.9 1.24 0.01 0.41
6 On row 11.1 79.9 62 5.4 5.3 1.22 0.01 0.43
7 No extra N 10.6 80.2 75 5.3 5.9 1.22 0.02 0.4
8 60 kg/ha N 11.4 80 52 5.3 4.3 1.25 0.01 0.44

Early dry matter kg/m2


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Late dry matter kg/m2


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Plant Establishment plants/m2


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Protein %


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Screenings %


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Test weight kg/hL


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Yellow leaf spot (0-10)


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Yield t/ha


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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 16, Minnipa Agricultural Centre, SA 0 - 20cm 7.90 1.76 28.00
Site 16, Minnipa Agricultural Centre, SA 0 - 60cm 105.00
Soil conditions
Trial site Soil texture
Site 16, Minnipa Agricultural Centre, SA Red sandy loam
Derived trial site soil information
Australian Soil Classification Source
Trial site Soil order
Site 16, Minnipa Agricultural Centre, SA Calcarosol
National soil grid Source
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 16, Minnipa Agricultural Centre SA 2015


Observed climate information
Rainfall avg ann (mm) 325mm
Rainfall avg gsr (mm) 242mm
Rainfall trial total (mm) 333mm
Rainfall trial gsr (mm) 258mm
Derived climate information
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BOM Data source MINNIPA PIRSA [4269] 0km proximity to trial site location


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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.