East Gippsland Soil Carbon Project

Lead organisation & Collaborators:

Agribusiness Gippsland Inc., and the Department of Primary Industries.

Contact:

Heather Adams

Department of Primary Industries

E: heather.adams@dpi.vic.gov.au

Year of study:

2008 to 2009

Location:

Bairnsdale, Swifts Creek and Orbost.

Soil type:

12 soils pits- different soil types (not specified), landscape and slopes at the different locations varied.

Average annual rainfall: 

Bairnsdale 710.2mm/a (BoM)
Swifts Creek 623.4mm/a (BoM)
Orbost 845.1mm/a (BoM)

 

Project details

Objectives:

The East Gippsland Soil Carbon Project provides baseline information on carbon levels under different land management types across East Gippsland. Trial sites will be identified using LUIM (land use impact model). Up to 15 trial pits have been established and 1000 soil samples tested.

Baseline soil carbon data will be used to investigate the effects of soil carbon on sustainable farming.

 

Hypotheses:

There are a series of benefits from increased soil carbon. This project intends to use this sampling to benchmark future sustainable farming practices. Specifically, soil carbon:

  • Improves soil structure
  • Improves nutrient status
  • Provides resilience against pH change
  • Improves water holding capacity of soil
  • Moderates changes in soil temperature

 

Basis of trial:

This project will gather baseline soil carbon information that may then be used to support investigation of the effects of soil carbon on sustainable farming.

How have results been reported?

Technical report.

How can a copy of any relevant reports be obtained?

Heather Adams

Department of Primary Industries.

Level of review of results:

Internal technical review.

Scientific Quality Assessment:

Objectives Conceptual model Study design Soil analysis Production & financial Method reporting Data analysis Results reporting Publication
4 1 1 3 1 4 2 3 3

Methods and Measures

[Picture accompanying results if supplied]

Screen Shot 2015-04-02 at 12.13.49 AM

Land managers were also surveyed for information about past management.

Treatment results:

Variation in soil C with time and management influence

  • Generally Total Soil Carbon levels decrease the deeper you go down into the profile.
  • The land use with the highest Total Soil Carbon from 0-10cm was Grazing Cattle High Production at 5.9g/100g.
  • The land use with the lowest Total Soil Carbon from 0-10cm was Mixed grazing 50% sheep and 50% cattle at 2.7g/100g.

Management History:

Pre-trial management: 187 sites in total– various grazing and cropping.

Trial management:  Not specified

Experimental Design:

Treatments: 15/12/2008-31/08/2009

Trial design/layout: Collect soil samples down to 40cm in 10cm sections under different land uses.
Dig soil pits (12) to provide more detailed information about soil types and characteristics in the region.

Methodology:

Production Measures:

    • Plant and/or animal production measurements: N/A
    • Cost and value of production: N/A

Soil Sampling Method:

10m diameter site selected and the top 10 cm of the centre of the circle was then augered out and discarded. The remaining three 10 cm intervals were then sampled using a 3-4 inch soil auger and the samples collected in separate buckets. This was repeated till each bucket had four samples. The collected top 10cm sample was placed in a labeled paper bag.

The remaining three samples were tipped individually onto plastic tarp. The pile of soil was spread and divided into quarters. Quarters were numbered from 12 o’clock from 1 to 4 in clockwise direction. 1 and 3 were discarded, 2 and 4 were retained and smoothed and the process repeated till the retained sample weighed approximately 1 kg. (This was usually done twice.) Samples were placed in paper bags labeled with site number, farmers name, and sample depth and sent to Werribee. At Werribee total carbon was measured, then ground samples to go to CSIRO and prepared a number to go to Adelaide to analyse fractions.

Samples tested for:

      • Total Carbon (Leico method)
      • Bulk density (FFSR biometrician)
      • Chemical analysis (not specified)
      • CSIRO Adelaide, Australasian Soil and Plant Analysis Council (ASPAC) accreditation

Next steps

Building soil carbon in pasture

      • Increase the proportion of perennial vegetation
      • Maintain ground cover through managing stocking rates
      • Minimise erosion

In cropping minimise carbon losses by:

      • retaining stubble
      • minimum cultivation
      • NO FALLOW

Incorporate a pasture phase.

This project could be applied to other sites.

      • Carbon fraction results will be available next year
      • Further examination of the data with respect to soil type and the paddock history forms