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

2014

Research organisatons
Funding source

Trial details

Aims

The majority of farms in low rainfall areas use sheep to provide enterprise diversity, however grazing also offers a range of other system benefits that are generally not accounted for in mixed farming enterprises. Studies have shown that grazing offers a useful tool for managing weeds and pests, improving crop nutrition and yields and providing an option to mitigate risk in pasture crop rotations. In these systems there is a perception of declining performance of the pasture ley, as a result of increasing cropping intensity. As a result, there has been work to show the benefits of increasing crop and pasture inputs, as opposed to district practice crop seeding and fertiliser rates and pasture regeneration from residual seed banks.

A long-term study was established at the Minnipa Agricultural Centre from 2008 to 2014 (EPFS Summaries 2008 to 2013) to assess the impact of grazing on crop and pasture production and soil health and also to evaluate this from a systems perspective.

The seven year demonstration with a wheat, wheat, pasture (volunteer and sown annual medic), wheat, pasture (self-regenerating annual medic), wheat and wheat rotation was also established to determine whether productivity could be improved under a higher input system compared to a lower input and more traditional system and what affect this had on soil fertility.

Key messages
  • There has been no evidence of any soil health or production losses with grazing after seven years, irrespective of whether crop or pasture inputs were increased or kept at district practice levels.
  • In 2014 higher input systems showed how increased inputs and costs throughout the season can result in increased productivity and subsequent profitability.
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 Cereal: Wheat
Treatment type(s)
  • Fertiliser: Rate
  • Grazing: Regime
  • Sowing: Rate
Trial type Demonstration
Trial design Unknown
Sow rate or Target density 50kg/ha
Sowing machinery Not specified
Sow date 10 May 2014
Harvest date 31 October 2014
Plot size 350m x 100m
Plot replication 1
Plot blocking Not specified
Plot randomisation Not specified
Paddock history 2013: Wheat2012: Medic pasture2011: Wheat2010: Medic pasture2009: Wheat2008: Wheat
Fertiliser

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 low and high input treatments respectively.

Herbicide

Weed control was imposed on all treatments as required in both summer and during the growing season.

Insecticide Not specified
Fungicide Not specified
Pesticide Not specified
Soil amelioration Not specified
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

# Variety
Treatment 1
Organic carbon (%) Grain yield (t/ha) Soil N (mg/kg) Emergence plants (plants/m2) Establishment plants (plants/m2) pH (value) Retention (%)
1 Wheat:Mace Low input - grazed 1 2.8 78 1.72 (P=0.05) 15.7 8 15.7
2 Wheat:Mace Low input - un-grazed 0.9 2.7 39 1.72 (P=0.05) 14.8 8 14.8
3 Wheat:Mace High input - grazed 1.1 3.5 85 1.72 (P=0.05) 19.4 8 19.4
4 Wheat:Mace High input - un-grazed 1.1 3.4 54 1.72 (P=0.05) 18.7 8 18.7
LSD 0.26 (P=0.05) 1.72 (P=0.05)

Grain yield t/ha


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Emergence plants plants/m2


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Establishment plants plants/m2


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Organic carbon %


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pH value


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Retention %


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Soil N mg/kg


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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 2014


Observed climate information
Rainfall trial gsr (mm) 290mm
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.