monitoring & data collection protocols · purpose 4 2. scope 4 3. background 5 4. general...

Technical Protocols AotGR1-167 of 30

Sequestering Soil Carbon in an Irrigated Landscape turned Dry Ecological Grazing

Monitoring & Data Collection Protocols

Project AoTGR1-167 Technical Report No. 1

May 2013


Version 1.2

Document Outline ACCEPTANCE AND RELEASE NOTICE

Role Name and Position title Signature Date

Project Director Shawn Butters, Director Kilter

Project Manager David Heislers, Sustainability & Natural Resources Analyst Kilter

Project Outline VERSION CONTROL REVISION HISTORY

Version Date revised Main Revisions

v1.0 Feb 2013

v1.1 Apr 2013 General grammatical and technical (Kym Luitjes)

V1.2 May 2013 Technical edit (Tom Baker)

This document is a managed document and the Project Manager is responsible for its development and maintenance. For identification of substantive amendments each page contains a version number and a page number. Please refer to the Version Control Identification Table for sequence of version numbers.

This project is supported by the Action on the Ground Program funded by the Australian Government


Contents

1. Purpose 4

2. Scope 4

3. Background 5

4. General Project Context 7

5. Specific Contextual Studies 8

6. Field Monitoring and Data Collection Activities 10

7. Trial Site Selection 12

8. Soil Survey Schedule 17

9. Soil Sampling Protocols 18

10. Soil Analysis Protocols 23

Appendix 1: Adapted SCaRP Protocols 26

Appendix 2: Responsibilities 28

Appendix 3: APAL Analysis Statement 29


1. Purpose This document presents the monitoring and data collection protocols for the AotG project Sequestering Soil Carbon in an Irrigated Landscape turned Dry Ecological Grazing (Pj. no. AotGR1-167).

2. Scope The primary focus of the document is to set out the protocols for the sampling, collection and analysis of soil carbon. Discussion of these processes is augmented here by the rationale and methods behind the contextual information that is important for the interpretation of the soil carbon data. Not all methods behind this contextual data have been resolved at the time writing, these will be developed during the course of the project.


3. Background Action on the Ground

The project is funded through round one (2011-12) of the Carbon Farming Futures - Action on the Ground program, administered by the Australian Government Department of Agriculture, Fisheries and Forestry.

The Australian Government’s Securing a Clean Energy Future plan, released in July 2011, contains four basic elements: introducing a carbon price; promoting innovation and investment in renewable energy; encouraging energy efficiency; and creating opportunities in the land sector to cut carbon pollution.

The land sector elements are about creating opportunities on the land whilst addressing carbon pollution. Significant opportunities exist within Australia’s agriculture sector to reduce carbon pollution and increase the amount of carbon stored on the land. Those who pursue these opportunities and develop methodologies will be rewarded through the Carbon Farming Initiative (CFI), which allows farmers and land managers to create credits for carbon bio-sequestration and pollution reduction activities associated with agricultural production.

The Carbon Land Sector package will assist farmers and land managers make the most of carbon farming opportunities. The package provides substantial funding through the Carbon Farming Futures (CFF) program for the Action on the Ground program to help land managers trial farming practices and technologies to reduce agricultural greenhouse gas emissions and sequester carbon in soil in order to be able to participate in the CFI.

Project Background

The project will trial and demonstrate regionally innovative on-farm practices aimed at increasing the sequestration of carbon in soil through a range of land management practices centred on the conversion from flood irrigated cropping to dryland grazing and protected biodiversity.

This project is to be managed from Kilter headquarters located in Bendigo in north-central Victoria. The project is about 150km to the NNW of Bendigo, on the Lower Loddon and Avoca floodplains between Kerang and Lake Boga, where Kilter Pty Ltd manages 9000 ha of semi-contiguous rural property – equivalent to around 40 individual farming properties.

The key premise of this project is that the return of permanent groundcover to the landscape - in this case to be managed as a controlled grazing and protected biodiversity operation - will see increased biomass and therefore enhanced opportunity for decomposing plant matter and therefore the sequestration of carbon in the soil. Formerly, the land of this project, was used for flood irrigated annual pasture and cropping. Through this use the land has become denuded (through landforming and traditional irrigated annual cropping/pasture management) relative to its natural state.

Ecological cell grazing is being introduced to this landscape and will be managed to maintain and encourage groundcover biomass and diversity – stock will be strategically removed during times of natural seed set. Regenerated native groundcover is the predominant forage type that, over time, will be assisted by purpose replanting and seeding. Management of protected biodiversity corridors to enhance native groundcover will be by both passive (fencing and pest plant & animal (PPA) control ) and more active (planting/seeding) means.


On the basis of existing scattered measurement, soil organic carbon across the general project landscape is typically less than 15 g/kg (or 1.5% by mass) However the cracking floodplain clays (vertosols) of the region are believed to offer good potential for soil carbon storage. This is in part because of slower rates of carbon depletion generally through clays, as well as enhanced opportunity for vertical downwards migration of carbon to more protected, deeper parts of the soil profile (by virtue of shrink-swell behaviour of surface clays).

The return of carbon to soil is typically a slow process and requires particular management intervention for it to be accrued and then retained - carbon restoration rates of 0.02 to 0.2%/yr (equivalent to 0.2 to 2 g/kg) have been typically observed in Victorian soils (ENRIC, 2010. Inquiry into Soil Carbon Sequestration in Victoria). Over the 3 year life of the proposed project it is hoped that a soil carbon increase of upwards of 1 g/kg (0.1%) can be measured.

With the last 2 years experiencing rainfall of Decile 9 or greater across northern Victoria the boost to vegetation growth, biomass and therefore soil carbon input increases the possibility that a statistically measureable soil carbon accrual will be able to be realised. In the longer term (20+ years) it is hoped than the grazing operation can return at least a 10 g/kg (1.0%) increase in the levels of soil carbon, translating to an average increase of 50 tCO2-e/ha in the top 10 cm alone (assuming a soil bulk density of 1400 kg/m3).


4. General Project Context The field monitoring, sampling and analysis framework of the project occurs within the following project context:

• The core of this trial area is the Future Farming Landscapes (FFL) 1250ha ‘Five-On-Seven’ grazing block west of Lake Tutchewop. Additional FFL paddocks to build grazing cell replicates and satisfy some of the landuse change (to biodiversity) scenarios are located on the east of the Murray Valley highway. Trial paddocks typically vary between 30 and 60ha in size.

• Paddock carbon calculation is being examined for four landuse change scenarios, these being former flood irrigation to (i) cell grazing, (ii) improved cell grazing, (iii) stock protected biodiversity and (iv) stock protected improved biodiversity. ‘Improved’ means that those areas have been subject to active restoration through direct seeding of grasses and chenopods (e.g. saltbush), undertaken 2 or more years prior to the first sampling and that the restoration process has measurably succeeded.

• Within the possibilities offered in the above, trial paddocks have been selected according to identification of visual spatial consistency of irrigation history; their location in the landscape; and intended future landuse. It is assumed that such candidate paddocks each approximate a single stratum to satisfy the statistical requirement of soil sampling and analysis. The assumptions around the selected strata will be tested by (i) soil-landform analysis; (ii) baseline soil carbon analysis and (iii) paddock landuse history that will be undertaken in the first year of the project.

• The preference was to have three trial paddock replicates for each of the four landuse change scenarios. In practice this was limited by availability of candidates, and is only achieved for the two grazing scenarios. However, given that the greatest spatial landuse change in FFL (and potentially beyond the borders of this project) is likely toward a dryland grazing regime, this limitation does not diminish the value of this project.

• There will be two spring sampling events in the project spaced two years apart, the first in October 2012 and then subsequently in 2014. There is provision for a smaller scale mid-project sampling event to further assess seasonality in soil carbon levels, though the timing and form of this will be driven by analysis of the baseline sampling event.

• Sampling and analysis protocols for this trial are to be consistent with the SCaRP carbon protocols as adapted to paddock scale soil carbon calculation (refer Attachment 1)

• Some additional sampling and analysis occurred in the first sampling event to understand soil carbon stocks in key reference areas, including (i) a recently active flood irrigation block and (ii) a long-protected biodiverse reserve. These are aimed to give a sense of the scope of soil carbon capability for the project area.

• At each sample site two depth intervals will be collected for Organic Carbon analysis, (i) 0-10 cm and (ii) 10-30 cm. In the first sampling event bulk density will be measured over the same intervals. The primary analysis will be for Organic Carbon (OC). This will be undertaken by Dumas combustion (the LECO method). Pre-treatment with acid will firstly remove the inorganic carbonate from the samples.

• In the first sampling event other basic analytes (pH, EC, nitrate, avail. P, metals) will be collected from all sites for general soil characterisation. These analytes will offer context around baseline soil carbon levels.

• The dates and the numbers of sheep grazed on trial paddocks will be recorded by the project to develop a measure of grazing pressure as well as to estimate offsetting carbon emissions associated with this landuse change.

• Other measures associated with biomass production and vegetation health will be developed and implemented during the project to understand the ecological thresholds of sustainable native dryland grazing - this has implication for the quantum of the carbon opportunity associated with this land use change.


5. Specific Contextual Studies A number of contextual studies are to be undertaken in 2013 that will provide important information into the interpretation of soil carbon measurement through the life of the project.

Soil-landform analysis

A desktop analysis of soil and landform will provide general physical context of the trial paddocks as well as contribute to the testing of these paddocks as explicit survey strata. This work is being undertaken by Sunraysia Environmental and is due to be completed in the 1st Qtr of 2013.

Land-use history

For each trial paddock landuse history will be documented. This will be especially focussed on the last 20-30 years of activity because this period is expected to be a key determinant on soil carbon levels. This information will assist in the understanding of the baseline soil carbon base levels undertaken in October 2012. This task is being undertaken by Kilter Rural with an initial version to be released in the 2nd Qtr of 2013. It is anticipated that this document will be refined over time as more knowledge incidentally comes to light.

Biomass production and vegetation health

Accrual of soil carbon is influenced by biomass production in the landscape. There is the opportunity in this project as part of its sustainable cell grazing operation to understand biomass production through a knowledge of stocking patterns and carrying capacity. The project will track stocking patterns (numbers of sheep over numbers of days in paddock), that while not necessarily highly correlated with biomass and groundcover, does nevertheless provide an indicator of production in a well managed grazing operation. This information will be augmented by the anecdotal observations of the project grazier on trial paddock performance.

During the project more sophisticated measures of groundcover and vegetation health will be established. For instance the project will have access to existing work being undertaken by Kilter Rural including a series of periodically monitored 30m vegetation health transects across the FFL landscape. Several of these are located on or nearby trial paddocks.

In addition Kilter Rural will work on implementing a rapid reconnaissance method of vegetation health that is applied to each trial paddock on a periodical (nominally annual) basis from Year 2. The design of such will consider elements of the Landscape Functional Analysis (LFA) approach of CSIRO (http://www.csiro.au/Organisation-Structure/Divisions/Ecosystem-Sciences/EcosystemFunctionAnalysis.aspx#a1)

Kilter Rural will produce a methods report on the above to be finalised in the 3rd Qtr of 2013, with initial actions to be implemented not later than the 4th Qtr 2013.


Grazing emissions

An important element of the project is to understand grazing traffic across the trial paddocks. This is not just to develop an understanding of sustainable grazing thresholds, but also to assess the carbon impacts of restocking (ie. methane emissions from ruminants) on net carbon sequestration. This information is important in the case that CFI carbon credits are to be generated from the type of land use change being examined by this project. The project grazier will provide trial paddock stocking records that will underpin this analysis through the life of the project.


6. Monitoring and Data Collection Activities

Table 6.1: Summary of project monitoring and data collection activities

Practice to be trialled The are four key landuse change scenarios that are the basis of this project, including: • Flood irrigation to ‘passively restored’ cell grazing (paddock recovered through rest, PPA control) • Flood irrigation to ‘actively restored’ grazing (ie. direct seeding activity took place 2+ yrs ago) • Flood irrigation to ‘passively restored’ protected biodiversity (has recovered through rest, stock

exclusion) • Flood irrigation to ‘actively restored’ protected biodiversity (ie. direct seeding activity took place 2+ yrs

ago)

Data to be collected For replicates in each landuse change scenario (up to 3 replicates depending upon the scenario) the following data is collected:

• Soil cores, analysed for Organic Soil Carbon in at least two full sampling events (in 1st and 3rd year of project)

• Additional Cores for Bulk Density determination collected during initial (baseline) sampling event.

• Bulked soil cores for basic soil analytes including: texture, pH, EC, nitrate, avail.P, std. metals in the baseline sampling event. These samples bulked to each replicate.

• Twice-annual photopoints to capture visual vegetation change in each trial paddock

• Periodical (nominally annual) rapid reconnaissance vegetation health assessment (informed by LFA) for all trial paddocks from Yr2

• Detailed vegetation health assessment along select 30m monitoring transects for species diversity and plant density (annual monitoring already undertaken by Kilter)

• Local climate data (monthly rainfall)

For grazing treatments only the additional data is collected:

• Log of stocking patterns (when and where of stock movement) and observation of stock/vegetation response in each trial paddock. Information collected by grazier


Sample collection technique (Soil) The most significant data collected by this project is organic soil carbon and associated physical and basic chemical analytes. Cores for analysis are extracted in the following manner:

Soil cores will be collected using a corer unit trailer mounted and towed by a 4WD. An on-board motor drives a hydraulic pump that pushes or gently vibrates the corer into the soil profile. For sample collection a plastic tube is placed inside a barrel, upon extraction the plastic tube is removed; the core is logged and divided into depth intervals (0-10 and 10-30cm).Samples are secured and temporarily stored in an insulated esky before being transported to APAL laboratories in Adelaide for analysis.

Sampling timing (Soil) • Spring 2012 (Baseline) – full survey of 9 trial paddocks. With additional chemical analytes and Bulk

Density. Also one-off sampling of 2 reference sites.

• Mid-project (Spring 2013 or Autumn 2014) partial resurvey. Potentially a resurvey of 1 replicate per treatment to test seasonal variation in soil carbon stocks. Design to be informed by Baseline survey.

• Spring 2014 – full repeat survey of soil organic carbon (no additional analytes or Bulk Density)

Analysis undertaken (Soil) Soil Analysis undertaken is consistent with the Adapted SCaRP protocols for AotG projects (Refer Appendix 1)

• Total Organic Carbon - LECO method with pre-treatment with acid to remove carbonates

• Bulk Density – heat and dry; sieve to <2mm; measure mass of known volume

• Basic soil analytes including texture, pH, EC, nitrate, avail.P, std. metals


7. Trial Site Selection Paddock carbon calculation is being examined across four landuse change scenarios, these being based around the conversion of former flood irrigation lands to dryland cell grazing and corridors of protected biodiversity. The treatments represent an example of a plausible farming future in northern Victoria in an era of increased water scarcity and the rationalisation of irrigation lands.

The treatments being tested in this project are described in the table:

Table 7.1: Trial paddock treatments

Paddock Treatment Types No. Replicates

1 Flood irrigation to ‘passively restored’ cell grazing

• Paddock recovered through rest and pest, plant and animal control

3

2 Flood irrigation to ‘actively restored’ grazing

• Paddock recovery assisted by direct seeding activity of native grasses, chenopods or native pasture

• This activity undertaken in 2010 or prior (2 yrs before initial soil survey) with significant visual and/or measurable success

3

3 Flood irrigation to ‘passively restored’ biodiversity

• Biodiversity value has recovered through stock exclusion and pest, plant and animal control

2

4 Flood irrigation to ‘actively restored’ biodiversity

• Paddock recovery assisted by direct seeding activity of native grasses or chenopods

• This activity undertaken in 2010 or prior (2 yrs before initial soil survey) with significant visual and/or measurable success

1

The core of this trial area is FFL’s 1250ha ‘Five-On-Seven’ grazing block west of Lake Tutchewop. However additional paddocks to make up the treatments are sourced from other FFL properties located on the eastern side of the Murray Valley Highway.

In addition to adopting the SCaRP related protocols of Jeff Baldock (see Appendix 1) agreed for AotG projects, the Project Reviewer Dr Tom Baker advocated the selection of three replicates for each treatment. This was readily achieved for the two grazing scenarios, but potential replicates for the biodiversity treatments were physically limited (1 active, 2 passive treatments).

Trial paddocks typically vary between 30 and 60ha, and given the relatively homogeneity of a floodplain landscape (in landform and soil distribution), are assumed to reasonably represent a single survey stratum. Paddocks within a given treatment were selected on the basis that, at least in a visual sense, each has a uniform and relatively straight forward physical imprint of past irrigation. In reality there will be physical and historical differences between replicates within a treatment that will need to be considered when comparing results. However the use replicates (chiefly in the grazing treatments) does offer some ability to test the effect of spatial variation in soil and landform characteristics.

In addition to the trial paddocks two references areas have been selected. These are designed to provide an idea of what soil carbon levels might be in (i) a more natural undisturbed area (Mystic Park Forest, bordering the Five-on-Seven block to the south) and (ii) where flood irrigation has continued to occur until very recently (paddock RFBJ2, a recently purchased FFL block that was earlier acquired by the state government as part of flood-affected land buyback scheme following the Jan 2011 floods).


Refer to the following table and map for identification and description of the selected trial paddocks in the project. The history of the trial paddocks will be more fully explored in a landuse history investigation to be undertaken in the first half of 2013.


Table 7.2: Key characteristics of project trial paddocks

Paddock ID Address Area (ha)

Landuse Treatment Characteristics of Treatment/Comment

FOSC2.1

Murray Valley Hwy, Tresco

38 Grazing with passive restoration

First sheep expected to enter paddock Spring 2012. Rotational sheep grazing through year. Date, duration and no. stock in paddock to be determined by grazier under sustainable management principles.

FOSC3.2 Cook Rd, Tresco 47 Grazing with passive restoration

First sheep entered paddock Winter 2012. Rotational sheep grazing through year. Date, duration and no. stock in paddock to be determined by grazier under sustainable management principles

FOSC4.2 Murray Valley Hwy, Tresco

33 Grazing with passive restoration

As above

GMGP2.1 Winlaton Rd, Fish Point 15 Grazing with active restoration

Hand broadcast direct seeding Apr 2010. First sheep entered paddock Winter 2012. Rotational sheep grazing through year. Date, duration and no. stock in paddock to be determined by grazier under sustainable management principles

GMCO7 Rob Roy Rd, Fish Point 60 Grazing with active restoration

Hand broadcast direct seeding Apr-Jun 2010. First sheep expected to enter paddock Spring 2012. Rotational sheep grazing through year. Date, duration and no. stock in paddock to be determined by grazier under sustainable management principles.

JCRO2 Three Chain Rd, Tutchewop

40 Grazing with active restoration

Air broadcast direct seeding Apr 2010. First sheep expected to enter paddock Spring 2012. Rotational sheep grazing through year. Date, duration and no. stock in paddock to be determined by grazier under sustainable management principles.

FOSC7 Benjeroop – Tresco Rd, Tresco

34 Protected biodiversity with passive restoration

Area fenced from stock. Passive Restoration. Area to be surveyed is outside registered BushTender zone.


KCLO3 Flood Lane, Lake Charm 28 Protected biodiversity with passive restoration

Area fenced from stock. Passive Restoration.

FPAG10 Vains Rd, Fish Point 2.3 Protected biodiversity with active restoration

Area fenced from stock. Active Restoration with air broadcast direct seeding Apr 2010.

RFBJ2

Lake Charm – Benjeroop Rd, Benjeroop

54 Reference area – recent flood irrigation

Irrigated dairy pasture up until early-2011 Lower Loddon flood (plain?)

Mystic Park State Forest

Baileys Rd, Mystic Park 200 Reference area – native vegetation

Long protected woodland reserve, though with some leased grazing history.


8. Soil Survey Schedule The soil survey schedule is designed to determine the change in soil carbon content across the landuse treatments over the life of the project. In practice this will be achieved by ‘bookend’ sampling events, scheduled for Spring (October) 2012 and again in Spring 2014. Timing of these events within a 2 yr window is constrained by the necessity for a detailed planning period in the beginning of the project as well as a documentation phase in the final project months.

Further, these events need to be undertaken at the same time of year to limit the influence of climate seasonality on organic soil carbon levels. This is further reason that the effective survey window is two years. An aspect of mid to late spring surveys are that they are reflective of a period of peak biomass growth and therefore near an assumed peak in the flux of carbon into the soil.

A further less intensive survey is planned for mid-project, either spring 2013 or autumn 2014. This is designed to assess the impact of intra-year seasonality of paddock soil carbon stocks. The final decision (i) on the efficacy of this and (ii) its design features will be informed by results of the baseline survey.

Table 8.1:

Survey Event Rationale General Survey Attributes

Spring (Oct) 2012

Baseline survey at beginning of project

• All replicates for all treatments (x9)

• Reference sites (x2)

• General soil analytes as well as organic soil carbon (& bulk density)

Spring (Oct) 2013 or Autumn (May) 2014

Survey to assess intra-year variability in soil carbon levels

• One replicate for each treatment

• Organic soil carbon

• Design to be informed by unitial survey

Spring (Oct) 2014

Final survey towards end of project to ascertain change from baseline

• All replicates for all treatments (x9)

• Organic soil carbon


9. Soil Sampling Protocols The minimum protocol for soil sampling in this project is that described by the Soil Carbon Research Programme (SCaRP). This associated soil sampling and analysis protocol - at the request of DAFF - was adapted to suit AotG projects. This adapted SCaRP protocol is detailed in Appendix 1).

The standards of SCaRP are embedded in a broader and more detailed set of protocols in this project that cover the following activities associated with sampling:

1. In-paddock Sampling Site Selection 2. In-paddock Navigation 3. Soil Coring Method 4. Sample Extraction and Bagging 5. Sample Storage and Transport

This set of protocols recognises the balance in efficiency and cost economy in soil sampling and the need for sufficient technical rigour required to calculate soil carbon within a paddock.

In-paddock Sampling Site Selection

The adapted SCaRP protocol indicates that a minimum of 10 soil samples should be collected across a stratum - nominally a paddock in the farming context - using random sampling or stratified random sampling within the boundary of the area of interest. Carbon stocks are then calculated for the specified area from the sampling data. Consistent with this, Project AotGR1-167 adopts a constrained randomised process to generate locations (co-ordinates) for soil sampling. Eighteen (18) sampling sites are to be derived for each trial paddock for each survey event. This occurs firstly by gridding each paddock into 18 cells of equal area (using Google Earth Pro), exporting this and then applying a location randomiser in ArcView 10. The randomiser is reapplied to generate new co-ordinates within the same grid for each sampling event. This approach enforces an even spread of sampling points across the trial paddock (via the gridding) with site coordinates then randomised within this constraint.


For the reference locations - that are only sampled in the baseline event – coordinates for 15 sampling sites are derived. The sampling is able to be relaxed in this instance because these are less about explicitly calculating paddock carbon and more about understanding soil carbon quanta within a landscape context.

A limitation applied to the outer grid boundary on a trial paddock is that it excludes un-irrigated sections of the paddock - such as service areas or paddock corners. Sampling would then explicitly focus on the former irrigated area, maximising the value of the sampling on the key area of the paddock. By definition calculated carbon stocks will apply to the area of the grid domain rather than strictly the area within the paddock fence lines. Given that trial paddocks are selected partly on the apparent homogeneity of their irrigation history, such un-irrigated sections are minor in area. Any adjustment applied to translate from ‘grid-area’ to ‘paddock-area’ carbon is therefore expected to be minor.

In-paddock Navigation

Navigating to sample site coordinates derived by the method described above is to be undertaken using a Differential GPS with sub-meter accuracy. The DGPS is mounted in the sample coring vehicle.

In practice there will be a number of potential factors that ultimately influence where the soil corer is set-down. These vary from in-paddock logistical issues to atypical paddock conditions (constraining the survey grid to the actual ex-irrigated zone deals with the latter point at the planning level).

Atypical physical features to be avoided when sampling would include (but not be limited to):

• Worn vehicular tracks • Fence lines (and associated tracks or firebreaks or other) • Irrigation infrastructure eg. channels and banks • Stock camps • Stock excretions

Other features will need to be avoided out of physical necessity (eg. a tree or large bush) or for reasons of environmental sensitivity. Biodiversity blocks being surveyed in the project are subject to BushTender or BushBroker management agreements with DSE, in which case disturbance needs to be kept to an absolute minimum.

Minimising trafficking across lands under protective covenant is planned to be achieved by:

• Minimising the distance travelled across the area • Designing and following a pre-survey route plan • Where appropriate accessing survey points from the paddock boundary (In BushBroker a

4m buffer inward from boundary fences is excluded) • Accessing these paddocks only under dry ground conditions • Backfilling of any excavations and removal of all foreign materials when complete

Accepting the above, the following rules provide a systematic process for navigating to and locating a theoretical sampling point on the ground:

1. The sampling point will be a minimum 5 m from a fence. If there is disturbed ground associated with the fence this 5 m is to be taken from the edge of the disturbed area.

2. The sampling point will remain 5 m from the edge of any un-natural or disturbed ground associated with irrigation channels, earthen banks or worn vehicular tracks


3. The sampling point will be at least 2 m from any particular aggregation of stock excretion (eg. a cow pat)

4. Any relocated sampling point should be placed inwards towards the centre of the grid cell the required offset distance from the edge of the disturbed ground (2 or 5 m). If the centre of the grid cell is not discernible then the relocation should occur in a northwards direction.

5. The sampling vehicle to be parked without bias to the distribution of vegetation or individual plants. The obvious exception being to avoid a tree, trampling a significant woody plant or damaging a purpose planted seedling, in which case a 2 m offset should apply.

6. Where a sampling point is relocated on the ground then the reason for this should be documented and actual sampling points will be located and recorded by DGPS (accurate to 50mm).

It is assumed that any soil carbon differences in soil beneath vegetation patches and interpatches (i.e. bare or mulched areas between living vegetation) will be averaged-out by the sampling program. While important for research, active discrimination between patches and interpatches infers a bias that can potentially impact on paddock carbon calculations. Previous sampling in the landscape by Kilter is inconclusive, though does not preclude a spatial relationship between patches/interpatches and local soil carbon content.

Soil Coring Method

The soil corer unit used in this project is trailer mounted with a tilting mast towed by a 4WD. An on-board motor drives a hydraulic pump to push or - if difficult ground - gently vibrates the corer (with 50 mm internal diameter) into the soil profile to the sampling depth of 30 cm.

For sample collection a plastic tube liner is to be placed inside the barrel – together with a sand core catcher. Upon extraction the plastic tube is removed, capped at the base and opened. The core then undergoes preliminary assessment, is split then bagged.

A cleaned or new liner is then inserted into the core barrel in readiness for the next site.

For bulk density calculation the internal dimensions of the core barrel are measured with callipers and supplied to the analysis lab.


Figure 1: The soil corer in action.

Sample Extraction and Bagging

At each sample site two depth intervals are to be collected for organic carbon analysis, (i) 0-10cm and (ii) 10-30 cm. In the 1st sampling event bulk density is to be measured over the same intervals. Each sample is separately bagged and clearly labelled in a zip-lock plastic bag.

In the first sampling event other basic analytes such as pH, EC, nitrate, available P and key metals are to be collected for soil characterisation. These are to be tested on a single composite or ‘bulked’ sample for each trial paddock or reference area.


Figure 2: Sample taken from corer barrel and bagged..

Sample Storage and Transport

The bagged samples and to be placed in an insulated esky to keep cool and for easy transport, before being delivered to the lab within 5 days of sampling under chain of custody documentation.


10. Soil Analysis Protocols Soil sample analysis in this project will be undertaken by APAL Laboratory Pty Ltd in South Australia.

APAL Laboratory Pty Ltd 489 The Parade, Magill, South Australia 5072 PO Box 327, Magill, South Australia 5072 Phone: 08 83320199 Fax: 08 83612715 Email: [email protected] http://www.apal.com.au/

APAL maintains a number of accreditations and quality control programs:

• APAL is a member of ASPAC (Australian Soil and Plant Analysis Council).which conducts annual laboratory proficiency programs.

• APAL is accredited for organic carbon and bulk density analysis.

Sample Preparation for Organic Carbon Determination

Consistent with the CFI adapted SCaRP protocol (Appendix 1), upon receipt by the laboratory the soil samples for organic carbon determination are to be air dried, ground (gravel removed) and passed through a 2 mm sieve. The <2 mm material is weighed and retained. The gravimetric water content is also determined. The dry weight of gravel material >2 mm is similarly recorded so a correction can be applied when calculating the soil carbon stock.

Bulk Density Determination

Separate cores are to be collected for Bulk Density determination. Where core samples are intact they are dried to a constant mass at 105°C. With the known dimensions of the core barrel the dry weight of the samples is divided by this volume to determine the bulk density.

Where core samples are not intact or look anomalous the samples upon drying to constant mass at 105°C, will be broken-up (using jaw crushers or the like) ensuring the sample is not ground finely. The soil mass is then measured in a container of known volume and bulk density determined from there.

Total Organic Carbon (TOC) Determination

Samples will firstly be tested for their inorganic carbon content using a ‘fizz test’ on a small portion. If there is any evidence of carbonate then the full sub-sample is subject to inorganic carbon removal (refer to Appendix 3 for detail).

Measurement of TOC is undertaken directly using the LECO method. This utilises high temperature combustion in the presence of oxygen. As it also combusts the inorganic fraction (lime) it is critical that this is removed first.

Quality Control

APAL uses in-house and purchased Certified Reference Material (CRM) to validate their analysis protocols and results. In-house CRMs are certified after analysing them a total of 30 times over 3 different days. Purchased CRMs are run every 5 samples during the certification process. APAL has a total of four purchased CRMs and 8 in-house CRMs for total soil carbon and soil nitrogen testing.


Statistical analysis is performed on the sample analysis and CRM results to determine the limits of error.


Abbreviations

AotG Action on the Ground (Program)

FFL Future Farming Landscapes

LFA Landscape Functional Analysis

PPA Pest Plants and Animals

SCaRP (National) Soil Carbon Research Programme

SOC Soil Organic Carbon

TIC Total Inorganic Carbon

TOC Total Organic Carbon


Appendix 1: Adapted ScaRP Protocols The attached protocol was supplied by Dr Jeff Baldock (CSIRO) in February 2012, providing input into the original project proposal. It recognises that sampling to calculate paddock carbon stocks is inherently different to the actual SCaRP.(http://www.csiro.au/science/Soil-Carbon-Research-Program) objectives and therefore survey design. The description below is adapted to the requirements of the CFF AotG program of which this project is a part.

To be consistent with data requirements of the Carbon Farming Futures research program, the following is considered to be the minimum sampling and analysis requirement for Action on the Ground projects:

1) Multiple (10 or more) soil samples should be collected using random sampling or stratified random sampling across the entirety of the area of interest (e.g. a paddock) on which comments pertaining to the measured carbon stocks are to be made. Special consideration of sample locations may be needed in row-based systems (e.g. orchards and permanent beds) where additional samples may be required to account for spatial differences between row and inter-row soil. Each sample should be kept separate and analysed separately to allow calculation of average soil carbon stocks and a standard deviation. This will allow comparisons between paddocks and comparisons over time to be made.

2) Replicated field experiments need to collect one composite sample per replicate treatment and then use the appropriate ANOVA to quantify treatment differences on soil carbon stocks.

3) A measurement of the dry soil bulk density is required at each sample location to allow carbon concentration data (%C) provided by an analytical laboratory to be converted into carbon stocks (Mg C/ha) (see Equation 1).

4) Sampling must occur to a minimum depth of 30 cm. It is suggested, but not essential, that the soil be sampled in 10 cm increments over the 0-30 cm soil layer. If a project wants to sample soil deeper than 30 cm that is acceptable; however, a measured carbon stock for the 0-30 cm layer separate from deeper soil carbon stocks will be required. Therefore any deeper sampling will have to be completed in at least two stages so that a 0-30 cm carbon stock and a >30 cm carbon stock can be derived.

5) The collected soil samples are to be air dried and sieved to <2 mm with all material passing through the 2 mm sieve being weighed and retained for subsequent carbon analysis. Note that the dry weight of any material >2 mm (gravel content) needs to be recorded and applied as a correction factor in calculating the soil carbon stock (see Equation 1).

6) The gravimetric water content of the air dried <2 mm material must be determined and used to correct any carbon content data if this was not done by the analytical laboratory. Whether an individual laboratory performs this correction or not needs to be confirmed with the laboratory used.

7) The gravimetric concentration of organic carbon (typically provided as %C) in the samples should be determined by sending the samples to an analytical laboratory accredited to perform this analysis. Ensure that samples containing carbonates are treated appropriately to provide a measurement of only organic carbon. A variety of accredited laboratories around Australia offer organic carbon analyses for soils. The gravimetric concentration of organic carbon is required for calculating the soil carbon stock using Equation 1.


8) To quantify soil carbon stock changes the sampling program has to be implemented at least twice (baseline assessment plus a measurement in the future). When considering temporal changes, the time of year and stage of crop/pasture development should be as constant as possible. The average and standard deviations obtained from the two or more samplings will be required to define the size of the soil carbon stock change associated with a defined level of confidence.

Equation 1 is used to calculate carbon stocks:

Soil carbon stock (Mg C/ha) = Soil carbon concentration (mg C/g soil) x soil layer depth (cm) x bulk density (Mg soil/m3 soil) x (1 – gravel content) x correction for units (108 cm2/ha x Mg/109 mg)

where the soil carbon concentration is reported as mgC/g soil (equal to 10 x %C), the soil layer depth is entered in cm, the bulk density is the value measured for the sample of soil analysed and the gravel content is the proportional mass of the soil material >2 mm (g >2mm soil/g soil).

Note 1: It is not a requirement to use MIR (mid-infrared spectroscopy) to derive estimates of carbon concentration or carbon fractions to define baseline carbon values for carbon accounting purposes.

Note 2: In the SCaRP program, samples were collected from a 25 m by 25 m area because the work being completed was not designed to quantify the stocks of carbon present across entire paddocks, but rather to define the potential impact of management practices across multiple paddocks. Under this scenario, the 25 m by 25 m area is one example of a soil by defined management combination and the mean and standard deviation across the aggregate of the areas sampled was available to quantify the influence of management practice. For carbon accounting across an area of interest (e.g. a paddock), the 25 m by 25 m area is not representative of the entire area and cannot be used to provide carbon account over the paddock.


Appendix 2: Responsibilities

Service Provider (Business)

Contact Telephone Responsibilities—i.e. sample collection, sample / data analysis

Sunraysia Environmental Pty Ltd

Kym Luitjes 03 5023 3643

0428 233 502

Soil survey logistics planning

Sample collection, storage and transport.

Oversight of soil analysis at APAL.

Data interpretation

APAL Pty Ltd Phil Barnett 08 8332 0199 Laboratory analysis and reporting of soil data

Kilter Rural David Heislers 03 5444 0112

0439 654 066

Soil survey specification

Vegetation health data collection

Formal reporting of analysis and interpretation


Appendix 3: APAL Analysis Statement

monitoring & data collection protocols · purpose 4 2. scope 4 3. background 5 4. general...

Documents