Grain & Graze 3 - The impact of livestock on paddock health

2013

Research organisatons
Funding source

Trial details

Aims

To test whether soil fertility and health could be improved under a higher input system (e.g. higher fertiliser and seeding rates, establishment of improved pasture) compared to a lower input and more traditional system (district practice seed and fertiliser inputs, volunteer pasture).

The six year (2008-2013) rotation of: wheat, wheat, pasture (volunteer and sown annual medic), wheat, pasture (annual medic – self regenerating) and wheat, was also split into grazed and un-grazed treatments in both the high and low input systems to establish the relative impact of grazing.

Key messages
  • There has been no measured grain production or soil health decline associated with grazing sheep on pastures and crop stubbles over a 4 year pasture-wheat rotation. Grain yields were higher as a result of increased wheat seed and fertiliser rates in 2013.
  • Higher applied crop seed and fertiliser rates with an improved medic pasture increased estimated gross margins by $16/ha/annum over a 6 year wheat-wheat-pasture-wheat-pasture-wheat rotation
Lead research organisation Southern Farming Systems
Host research organisation SARDI Minnipa Agricultural Centre
Trial funding source GRDC SFS00028
Related program Grain & Graze 3
Acknowledgments

We gratefully acknowledge the help of Mark Klante and Brett McEvoy for site management and Ian Richter and Wade Shepperd for data collection.


Other trial partners EP, BCG, MSF, Ag Excellence Alliance
Download the trial report to view additional trial information

Method

Crop type
Treatment type(s)
  • Fertiliser: Rate
  • Grazing: Regime
  • Sowing: Rate
Trial type Experimental
Trial design Replicated

Minnipa Agricultural Centre 2013

Sow rate or Target density 50kg/ha
Sow date 5 May 2013
Harvest date 4 November 2013
Plot size 350m x 100m
Plot replication 1
Paddock history 2013: Wheat2012: Medic pasture2011: Wheat2010: Medic pasture2009: Wheat2008: Wheat
Fertiliser <p>7 kg N/ha and 8 kg P/ha (45 kg/ha DAP) and 70 kg/ha with 13 kg N/ha and 15 kg P/ha (75 kg/ha DAP) for the traditional (low) and high input treatments respectively.</p>
Herbicide <p>Weed control was imposed on all treatments as required in both summer and during the growing season.</p>
Download the trial report to view additional method/treatment information

Trial results Table 1

# Variety
Treatment 1
Screenings (%) Soil N (mg/kg) Dry matter (t/ha) Organic carbon (%) Protein (%) Grain yield (t/ha) Colwell phosphorus (mg/kg) Water use efficiency (kg/ha/mm) Establishment plants (plants/m2)
1 Wheat:Mace Low input - grazed 5.6 111 5.3 1.3 10.3 1.9 34 15 127
2 Wheat:Mace Low input - un-grazed 4.7 84 5.4 1.2 10.3 1.8 27 14 124
3 Wheat:Mace High input - grazed 6.3 118 6.3 1.2 11.2 2.1 18 16 175
4 Wheat:Mace High input - un-grazed 5.6 74 6.1 1.1 10.8 2.1 22 16 158

Grain yield t/ha


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Colwell phosphorus mg/kg


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Dry matter t/ha


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Establishment plants plants/m2


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Organic carbon %


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Protein %


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Screenings %


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Soil N mg/kg


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Water use efficiency kg/ha/mm


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Observed trial site soil information
Trial site soil testing
Not specified
Soil conditions
Trial site Soil texture
Site 17, Minnipa Agricultural Centre, SA Red sandy loam
Derived trial site soil information
Australian Soil Classification Source
Trial site Soil order
Site 17, 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 17, Minnipa Agricultural Centre SA 2013


Observed climate information

Rainfall trial gsr (mm) 237mm

Derived climate information

Site 17, Minnipa Agricultural Centre SA

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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.