Mega Redport Pty Ltd...Mega Redport Pty Ltd Lake Maitland Baseline Soil Survey September 2007 Outback Ecology Services 1/71 Troy Terrace Jolimont WA 6014 Ph: +61 (08) 9388 8799 Fax:

Mega Redport Pty Ltd

Lake Maitland Baseline Soil Survey

September 2007

Outback Ecology Services 1/71 Troy Terrace Jolimont WA 6014 Ph: +61 (08) 9388 8799 Fax: +61 (08) 9388 8633 [email protected]

mailto:[email protected]

Lake Maitland Baseline Soil Survey Distribution: Company Copies Contact NameMega Redport Pty Ltd 3 hard copies D. Button

1 electronic copy

Document Control for Job Number: Author Reviewer Signature Date of Issue C. Weston D. Jasper DJ September 2007 M. Braimbridge

DISCLAIMER, CONFIDENTIALITY AND COPYRIGHT STATEMENT © Outback Ecology. All rights reserved. No part of this work may be reproduced in any material form or communicated by any means without the permission of the copyright owner.

This document is confidential. Neither the whole nor any part of this document may be disclosed to any third party without the prior written approval of Outback Ecology and Mega Redport Pty Ltd.

Outback Ecology undertook the work, and prepared this document, in accordance with specific instructions from Mega Redport Pty Ltd to whom this document is addressed, within the time and budgetary requirements of Mega Redport Pty Ltd. The conclusions and recommendations stated in this document are based on those instructions and requirements, and they could change if such instructions and requirements change or are in fact inaccurate or incomplete.

Outback Ecology has prepared this document using data and information supplied to Outback Ecology by Mega Redport Pty Ltd and other individuals and organisations, most of whom are referred to in this document. Where possible, throughout the document the source of data used has been identified. Unless stated otherwise, Outback Ecology has not verified such data and information. Outback Ecology does not represent such data and information as true or accurate, and disclaims all liability with respect to the use of such data and information. All parties relying on this document, do so entirely at their own risk in the knowledge that the document was prepared using information that Outback Ecology has not verified.

This document is intended to be read in its entirety, and sections or parts of the document should therefore not be read and relied on out of context.

The conclusions and recommendations contained in this document reflect the professional opinion of Outback Ecology, using the data and information supplied. Outback Ecology has used reasonable care and professional judgment in its interpretation and analysis of the data. The conclusions and recommendations must be considered within the agreed scope of work, and the methodology used to carry out the work, both of which are stated in this document.

This document was intended for the sole use of Mega Redport Pty Ltd and only for the use for which it was prepared, which is stated in this document. Any representation in the document is made only to Mega Redport Pty Ltd. Outback Ecology disclaims all liability with respect to the use of this document by any third party, and with respect to the use of and reliance upon this document by any party, including Mega Redport Pty Ltd for a purpose other than the purpose for which it was prepared.

Outback Ecology has conducted environmental field monitoring and/or testing for the purposes of preparing this document. The type and extent of monitoring and/or testing is described in the document.

On all sites, there exists varying degrees of non-uniformity of the vertical and horizontal soil and water conditions. Because of this non-uniformity, no monitoring, testing or sampling technique can completely eliminate the possibility that the results/samples obtained through monitoring or testing are not entirely representative of the soil and/or groundwater conditions on the site. Any conclusions based on the monitoring and/or testing only serve as an indication of the environmental condition of the site (including the presence or otherwise of contaminants or emissions) at the time of preparing this document.

It should be noted that site conditions, including the exact location, extent and concentration of contaminants, can change with time.

Subject to the limitations imposed by the instructions and requirements of Mega Redport Pty Ltd, the monitoring and testing have been undertaken in a professional manner, according to generally-accepted practices and with a degree of skill and care which is ordinarily exercised by reputable environmental consultants in similar circumstances. Outback Ecology makes no other warranty, express or implied.

Executive Summary

Outback Ecology Services (OES) was commissioned by Mega Redport Pty Ltd to conduct a baseline

soil survey of the Lake Maitland Uranium Deposit, located in the vicinity of the northern portion of

Lake Maitland, approximately 95 km north-east of Leinster, and 105 km south-east of Wiluna, on the

Barwidgee Pastoral Lease, Western Australia. The survey was one component of a broader study

undertaken concurrently by Outback Ecology that also assessed vegetation and flora, fauna, aquatic

ecology and stygofauna of the Lake Maitland Uranium Deposit lease area.

The soil survey and laboratory analyses of ‘surface’ soils (to approximately 1m depth) indicated a

wide range of existing soil properties between, and in some instances within, the landform /

vegetation associations investigated, namely the spinifex / acacia, spinifex, calcrete and lake playa

associations.

Soil Chemical Characteristics

The soils sampled exhibited a wide range of pH values with some consistency between soil pH and

position within the landscape or vegetation community (Table A). The soils from within the lake playa

and calcrete areas were generally more alkaline than those from within the spinifex and spinifex /

acacia vegetation associations, with both the latter areas exhibiting a wide range of soil pH values.

There was also a wide range in salinity values across the study area. As expected the samples from

the lake playa recorded the highest salinity levels.

Soil nutrient analyses indicated generally low levels of available nutrients (available N, P, K and S)

that are typical for the region. Levels of most nutrients tested were marginally higher in the lake playa

soils compared to samples from the other areas.

Measurements of total metal concentration of the surface samples collected indicated that only very

low levels of As, Cd, Cr, Cu, Pb, Ni, Zn and Hg were present. Many materials sampled were below the

detectable limit for As, Cd, Pb, Zn and Hg, with only Cr, Cu and Ni regularly detected at a reportable

level. For the metals detected, there was no apparent correlation with landform / vegetation

association.

Soil Physical Characteristics

There was significant variation in most of the physical soil attributes measured (Table A). Soil textures

ranged from loamy sand to light medium clay. In general, finer textured soils were present within the

lake playa. Soil structure was also variable, with little trend attributable to position within the

landscape or vegetation association.

Many soils sampled exhibited dispersive properties, or the tendency to disperse following severe

disturbance. This indicates that these materials may be potentially problematic once disturbed and

re-deposited. Measurements of soil strength upon drying indicated that the majority of the soils

assessed did not hardset.

The water retention characteristics of the soils measured were variable, reflecting the variability in soil

texture and amount of coarse material (>2 mm) across the study area.

Table A: Summary of ranges in values of physical and chemical characteristics for soils,

grouped into landform / vegetation associations.

Soil / vegetation association

Spinifex / Acacia Spinifex Calcrete Lake playa

Soil texture Loamy sand to clay loam

Clayey sand to light medium clay

Sandy loam to clay loam

Clayey sand to light medium clay

Soil structure

Variable – single grained to weak /

moderate aggregates to

massive

Variable – single grained to weak /

moderate aggregates to

massive

Single grained to weak aggregates

Single grained to weak / moderate

aggregates

% Coarse material 2 to 67

(increasing with depth)

2 to 50 14 to 42 0 to 15

Soil pH (H2O) 4.9 to 9.3 5.3 to 7.8 8.1 to 9.2 8.1 to 8.8 Electrical conductivity (dS/m)

Non saline (0.02) to extremely saline

(3.8)

Non saline (0.01) to very saline (1.4)

Non saline (0.1) to extremely saline

(2.3)

Extremely saline (4.0 to 9.9)

Nutrient status Low Low Moderate Moderate

Organic carbon (%) Low, 0.19 to 0.64 Low, 0.17 to 0.33 Moderate, 0.64 to

0.71 Moderate, 0.28 to

0.75

Structural stability Variable, potentially dispersive soils at

some sites

Variable, potentially

dispersive soils at some sites

Variable, potentially dispersive soils at

some sites

Slaking, no dispersion1

Soil strength – penetration resistance (MPa)

Variable, 0.5 to 11.2

Variable, 0.8 to 14.3 Low, 0.5 to 2.5 Moderate, 0.2 to

3.4

Hardsetting (MOR kPa) Low, 0.6 to 36 Low, 2 to 31 Low, 14 to 41 Moderate, 5 to 106

Bulk density (g/cm3) 1.32 to 1.75 1.59 to 1.75 1.32 to 1.42 0.91 to 1.24

Water holding capacity2

Variable – low to moderate Moderate Moderate High

1. potentially dispersive properties may be masked by flocculating effects of high salinity

2. relative to study area, based on broad characterisation of water retention characteristics and particle size distributions

Conclusions and recommendations

Issues requiring consideration during project development include:

topsoil and subsoil / overburden management;

the poor structural stability (slaking and dispersion) of some ‘surface’ soils; and

the physical / chemical characteristics of deeper regolith materials.

Generally speaking, direct return of topsoils is preferred where possible, alternatively, ‘paddock-

dumped’ soil stockpiles are recommended. Stockpiles and waste landforms, if required, should be

designed and constructed to minimize the potential for erosion. Finally, further quantification of the

properties of deeper regolith materials is recommended as the project develops, to ensure

appropriate management of these materials.

Mega Redport Pty Ltd Lake Maitland – Baseline Soil Survey

TABLE OF CONTENTS

1.0 INTRODUCTION .......................................................................................................................... 5 1.1 LOCATION OF PROJECT AREA ....................................................................................................... 5 1.2 SOILS AND LAND SYSTEMS OF THE PROJECT AREA....................................................................... 6

2.0 MATERIALS AND METHODS..................................................................................................... 8 2.1 SAMPLING REGIME....................................................................................................................... 8 2.2 TEST WORK AND PROCEDURES .................................................................................................. 10

3.0 RESULTS AND DISCUSSION................................................................................................... 10 3.1 SOIL PROFILE DESCRIPTIONS .................................................................................................... 10

3.1.1 Site 1................................................................................................................................ 11 3.1.2 Site 2................................................................................................................................ 13 3.1.3 Site 3................................................................................................................................ 15 3.1.4 Site 4................................................................................................................................ 17 3.1.5 Site 5................................................................................................................................ 19 3.1.6 Site 6................................................................................................................................ 21 3.1.7 Site 7................................................................................................................................ 23 3.1.8 Site 8................................................................................................................................ 25 3.1.9 Site 9................................................................................................................................ 27 3.1.10 Site 10.............................................................................................................................. 29 3.1.11 Site 11.............................................................................................................................. 31 3.1.12 Site 12.............................................................................................................................. 33 3.1.13 Site 13.............................................................................................................................. 35 3.1.14 Site 14.............................................................................................................................. 37 3.1.15 Site 15.............................................................................................................................. 39

3.2 SOIL CHEMICAL PROPERTIES ..................................................................................................... 41 3.2.1 Soil pH ............................................................................................................................. 41 3.2.2 Electrical Conductivity...................................................................................................... 42 3.2.3 Soil Organic Matter .......................................................................................................... 42 3.2.4 Soil Nutrients.................................................................................................................... 43 3.2.5 Heavy Metals ................................................................................................................... 46

3.3 SOIL PHYSICAL PROPERTIES...................................................................................................... 48 3.3.1 Soil Profile Morphology.................................................................................................... 48 3.3.2 Soil Texture...................................................................................................................... 48 3.3.3 Soil Structure ................................................................................................................... 48 3.3.4 Structural Stability............................................................................................................ 49 3.3.5 Soil Strength .................................................................................................................... 51

3.3.5.1 Modulus of Rupture ....................................................................................................................51 3.3.5.2 Soil Penetration Resistance........................................................................................................52

3.3.6 Soil Water Retention........................................................................................................ 53 3.3.7 Root growth...................................................................................................................... 55

4.0 CONCLUSIONS AND RECOMMENDATIONS ......................................................................... 56 4.1 SOIL STRIPPING AND MANAGEMENT FOR REHABILITATION............................................................. 57 4.2 FURTHER WORK ........................................................................................................................ 57

5.0 REFERENCES ........................................................................................................................... 58

List of Figures Figure 1 Locality map of the Lake Maitland project area (Redport Limited, 2006)...............................6 Figure 2 Location of sampling sites at Lake Maitland...........................................................................9 Figure 3 Individual and average soil pH (H2O) values grouped into spinifex / acacia, spinifex,

lake playa and calcrete sites (Error bars represent standard error).....................................41


Figure 4 Individual and average electrical conductivity (EC 1:5 H2O) values grouped into spinifex

/ acacia, spinifex, lake playa and calcrete sites (Error bars represent standard error). .......42 Figure 5 Individual and average soil organic carbon (%) values grouped into spinifex / acacia,

spinifex, lake playa and calcrete sites (Error bars represent standard error). .....................43 Figure 6 Individual and average nitrate N (mg/kg) values grouped into spinifex / acacia, spinifex,

lake playa and calcrete sites (Error bars represent standard error).....................................44 Figure 7 Individual and average ammonium N (mg/kg) values grouped into spinifex / acacia,

spinifex, lake playa and calcrete sites (Error bars represent standard error). .....................44 Figure 8 Individual and average extractable phosphorus (P) (mg/kg) values grouped into spinifex

/ acacia, spinifex, lake playa and calcrete sites (Error bars represent standard error). .......45 Figure 9 Individual and average extractable potassium (K) (mg/kg) values grouped into spinifex /

acacia, spinifex, lake playa and calcrete sites (Error bars represent standard error). .........45 Figure 10 Individual and average extractable sulphur (S) (mg/kg) values grouped into

spinifex/acacia, spinifex, lake playa and calcrete sites (Error bars represent standard

error). ....................................................................................................................................46 Figure 11 Individual and average modulus of rupture (kPa) values grouped into spinifex/acacia,

spinifex, lake playa and calcrete sites (Error bars represent standard error). Red line

indicates potential restrictions to plant and root development (Cochrane and Aylmore

1997).....................................................................................................................................52 Figure 12: Individual and average penetration resistance (MPa) values grouped into

spinifex/acacia, spinifex, lake playa and calcrete sites (Error bars represent standard

error). ....................................................................................................................................53 Figure 13 Soil water retention curves for <2mm fraction of selected soil samples ..............................54

List of Tables Table 1 Summary of Land Systems over the project area (Pringle et al., 1994) ................................7 Table 2 Summary table of sampling site locations and soil / vegetation complexes. .........................8 Table 3 Soil physical characteristics for Site 1 ..................................................................................12 Table 4 Soil chemical characteristics for Site 1.................................................................................12 Table 5 Soil physical characteristics for Site 2 ..................................................................................14 Table 6 Soil chemical characteristics for Site 2.................................................................................14 Table 7 Soil physical characteristics for Site 3 ..................................................................................16 Table 8 Soil chemical characteristics for Site 3.................................................................................16 Table 9 Soil physical characteristics for Site 4 ..................................................................................18 Table 10 Soil chemical characteristics for Site 4.................................................................................18 Table 11 Soil physical characteristics for Site 5 ..................................................................................20 Table 12 Soil chemical characteristics for Site 5.................................................................................20 Table 13 Soil physical characteristics for Site 6 ..................................................................................22 Table 14 Soil chemical characteristics for Site 6.................................................................................22 Table 15 Soil physical characteristics for Site 7 ..................................................................................24


Table 16 Soil chemical characteristics for Site 7.................................................................................24 Table 17 Soil physical characteristics for Site 8 ..................................................................................26 Table 18 Soil chemical characteristics for Site 8.................................................................................26 Table 19 Soil physical characteristics for Site 9 ..................................................................................28 Table 20 Soil chemical characteristics for Site 9.................................................................................28 Table 21 Soil physical characteristics for Site 10 ................................................................................30 Table 22 Soil chemical characteristics for Site 10...............................................................................30 Table 23 Soil physical characteristics for Site 11 ................................................................................32 Table 24 Soil chemical characteristics for Site 11...............................................................................32 Table 25 Soil physical characteristics for Site 12 ................................................................................34 Table 26 Soil chemical characteristics for Site 12...............................................................................34 Table 27 Soil physical characteristics for Site 13 ................................................................................36 Table 28 Soil chemical characteristics for Site 13...............................................................................36 Table 29 Soil physical characteristics for Site 14 ................................................................................38 Table 30 Soil chemical characteristics for Site 14...............................................................................38 Table 31 Soil physical characteristics for Site 15 ................................................................................40 Table 32 Soil chemical characteristics for Site 15...............................................................................40 Table 33 Individual total metal values (mg/kg) for selected soil horizons at all sites. .........................47 Table 34 Summary of slaking/dispersion properties (Emerson Test) results, indicating structural

stability. Emerson Test classes are included in Appendix B ...............................................50 Table 35 Range of plant available water (PAW) (%) for selected samples, corrected for % coarse

material (>2mm) ...................................................................................................................54

List of Plates

Plate 1 Soil Profile at Site 1...................................................................................................................11 Plate 2 Vegetation at Site 1...................................................................................................................11 Plate 3 Soil Profile at Site 2...................................................................................................................13 Plate 4 Vegetation at Site 2...................................................................................................................13 Plate 5 Soil Profile at Site 3...................................................................................................................15 Plate 6 Vegetation at Site 3...................................................................................................................15 Plate 7 Soil Profile at Site 4...................................................................................................................17 Plate 8 Vegetation at Site 4...................................................................................................................17 Plate 9 Soil Profile at Site 5...................................................................................................................19 Plate 10 Vegetation at Site 5.................................................................................................................19 Plate 11 Soil Profile at Site 6.................................................................................................................21 Plate 12 Vegetation at Site 6.................................................................................................................21 Plate 13 Soil Profile at Site 7.................................................................................................................23 Plate 14 Vegetation at Site 7.................................................................................................................23 Plate 15 Soil Profile at Site 8.................................................................................................................25 Plate 16 Vegetation at Site 8.................................................................................................................25


Plate 17 Soil Profile at Site 9.................................................................................................................27 Plate 18 Vegetation at Site 9.................................................................................................................27 Plate 19 Soil Profile at Site 10...............................................................................................................29 Plate 20 Vegetation at Site 10...............................................................................................................29 Plate 21 Vegetation at Site 11...............................................................................................................31 Plate 22 Soil Profile at Site 12...............................................................................................................33 Plate 23 Vegetation at Site 12...............................................................................................................33 Plate 24 Soil Profile at Site 13...............................................................................................................35 Plate 25 Vegetation at Site 13...............................................................................................................35 Plate 26 Soil Profile at Site 14...............................................................................................................37 Plate 27 Vegetation at Site 14...............................................................................................................37 Plate 28 Soil Profile at Site 15...............................................................................................................39 Plate 29 Vegetation at Site 15...............................................................................................................39 Plate 30 Examples of dispersed (b and c (minor)) and flocculated (a,d,e,f) 1 : 5 soil : water

suspensions..........................................................................................................................51

Appendices Appendix A Glossary of Terms............................................................................................................60 Appendix B Summary of Outback Ecology Soil Analysis methods.....................................................63 Appendix C Summary of Outback Ecology Soil Analysis results ........................................................66 Appendix D Summary of CSBP Soil Analysis results .........................................................................68 Appendix E Soil Electrical Conductivity (EC) classes.........................................................................71 Appendix F Root Scoring categories...................................................................................................73 Appendix H Slaking / Dispersion examples.........................................................................................75


5

1.0 INTRODUCTION

Mega Redport Pty Ltd is currently undertaking a pre-feasibility study in respect to the development of

a series of prospective uranium exploration tenements (E53/1060, E53/1099 and E53/947) located on

Lake Maitland.

Outback Ecology Services (OES) was commissioned by Redport Limited to conduct a baseline soil

survey of the Lake Maitland Uranium Deposit project area during May 2007. This survey was one

component of a broader study undertaken concurrently by Outback Ecology that also assessed

vegetation and flora, fauna, aquatic ecology and stygofauna of the project area. The objectives of the

soil survey were:

• to develop a general understanding of soils and their properties in the project area, in relation

to vegetation and landform type;

• to provide baseline information identifying potentially problematic surface soil materials; and

• to provide information to assist with the development of recommendations for managing soils /

regolith materials for optimum rehabilitation outcomes.

The proposed mining operations are to include an open-cut mine and associated infrastructure. At the

time of survey, no exact locations for infrastructure had been identified, except for the mine camp.

Soil sample sites were chosen to encompass the range of landform and vegetation communities

present within the lease area. This report documents the results of this survey and includes:

• descriptions of soil profile morphology, to the maximum depth possible, based on Australian

Soil Classification Standards;

• evaluation of soil physical parameters (soil structure, soil texture, hardsetting, water retention

characteristics);

• measurement of soil chemical parameters (soil pH, electrical conductivity, ammonium and

nitrate N, extractable P, K and S, organic C and total metals); and

• examination of possible correlations between measured soil properties, landform and

vegetation communities.

1.1 Location of project area

The Lake Maitland Uranium Deposit is located in the the northern portion of Lake Maitland,

approximately 95 km northeast of Leinster and 105 km southeast of Wiluna, in the Murchison region of

Western Australia (Figure 1). The project area is located on Barwidgee Pastoral Lease and is

comprised of three Exploration Leases; E53/947, E53/1060 and E53/1099.


6

Figure 1 Locality map of the Lake Maitland project area (Redport Limited, 2006)

1.2 Soils and Land Systems of the Project Area

The project area lies within the Eastern Murchison. Previous investigations have characterised the

region by its internal drainage and salt lake systems associated with an occluded paleodrainage

system, areas of red sand plains, broad plains of red-brown soils, and breakaway complexes (Cowan,

2001).

A regional survey of land in the north-eastern Goldfields was undertaken between 1988 – 1990 by the

Department of Agriculture and the Department of Land Administration. The purpose of the survey was

to develop a comprehensive description of the biophysical resources and an assessment of the

condition of the soils and the vegetation (Pringle et al., 1994). A component of the survey was the

mapping of land types, land systems and land units.

The Lake Maitland project area is located over five land types and seven land systems (Table 1), with

the Darlot and Bullimore land systems dominating the project area. The Darlot Land System

represents the Lake Maitland salt lake and fringing saline alluvial plains, while the Bullimore Land

System represents extensive spinifex sandplains to the east of the lake. Calcrete platforms of the

Mileura Land System supporting mainly halophytic shrublands occur adjacent to Lake Maitland, and


7

Mulga shrublands on sandy-surfaced plains occur on the Melaleuca Land System further from the

lake’s edge.

Table 1 Summary of Land Systems over the project area (Pringle et al., 1994)

Land Type Land System Description

Total and % of north –eastern

Goldfields

Predominant location over project area

Land Type 13 Sandplains with spinifex hummock grasslands, Acacia shrublands, heath and eucalypts.

Bullimore (Blm)

Extensive sandplains supporting spinifex hummock grasslands.

24,013 km²

24 %

Extensive representation over the project area, particularly to the east.

Land Type 17 Salt lakes and fringing alluvial plains with saline soils and halophytic shrublands

Darlot (Dar)

Salt lakes and fringing saline alluvial plains, with extensive, regularly arranged, sandy banks and numerous claypans and swamps supporting halophytic shrublands and spinifex and wanderrie grasslands.

1,344 km²

1.3 %

Extensive representation across Lake Maitland, including the project area.

Mileura (Mle)

Calcrete platforms and saline alluvial plains, supporting halophytic shrublands.

550 km²

0.6 %

Northern section of Lake Maitland, intersecting or abutting Darlot Land System.

Land Type 15 Calcreted drainage plains with mixed halophytic and non-halophytic shrublands. Melaleuca

(Mel)

Sandy-surfaced plains and calcareous plains, supporting spinifex or mulga wanderrie shrublands.

267 km²

0.3 %

Scattered on edges of Lake Maitland, often intersecting or abutting Darlot Land System.

Desdemona (Des)

Extensive plains with deep sandy or loamy soils, supporting mulga and wanderrie grasses.

2,524 km²

2.5 %

Northwest corner of project area abutting Bullimore Land System

Land Type 12 Plains with deep sandy soils supporting Acacia shrublands (occasionally with mallees) and wanderrie grass Ararak

(Ara)

Broad plains with mantles of ironstone gravel supporting mulga shrublands with wanderrie grasses.

2,021 km²

2.0 %

Scattered, with a minor occurrence in the extreme north of the project area.

Land Type 9 Plains with gritty surfaces and low tors and domes on granite with Acacia shrublands

Challenge (Clg)

Gently undulating plains, occasional granite hills, tors, and low breakaways with Acacia shrubland

554km²

0.6 %

Isolated occurrence in the extreme east of the project area.


8

2.0 MATERIALS AND METHODS

2.1 Sampling regime

A total of 15 soil sites were investigated within the Lake Maitland lease area (Table 2, Figure 2). The

selected sites encompassed a range of landform and vegetation units within the survey area. For the

comparative purposes of this study, the sites were grouped according to either their position within the

landscape and / or their vegetation associations, namely as spinifex / acacia, spinifex, lake playa or

calcrete.

Soil pits were excavated by backhoe and by hand as deep as possible, to a maximum depth of 1.5m.

The soil profile was described (soil profile morphology, soil structure, root distribution) based on the

Australian Soil and Land Survey Handbook (McDonald et al. 1998). Soil samples were collected from

consistent depth intervals within each profile, for analyses of chemical and physical parameters.

Table 2 Summary table of sampling site locations and soil / vegetation complexes.

Coordinates (Projection: UTM Zone 51J,

Datum: GDA94) Site # Soil /

Vegetation complex

easting (mE) northing (mN)

Elevation (m)

1 spinifex / acacia 0311737 6997212 449

2 spinifex / acacia 0312327 6998430 487

3 spinifex / acacia 0312351 7000175 476

4 spinifex 0312353 7002099 478

5 spinifex 0314079 6997929 478

6 spinifex / acacia 0313581 6992499 479

7 spinifex 0314224 6990898 475

8 lake playa 0309991 6992458 471

9 lake playa 0310821 6991976 474

10 calcrete 0309766 6993338 473

11 calcrete 0308777 6995079 468

12 lake playa 0309591 6994978 514

13 calcrete 0307556 6994501 474

14 spinifex / acacia 0312339 6993177 480

15 lake playa 0310530 6996954 469

314000 mE310000 mE 312000 mE

6992

000

mN

6992000 mN

6994

000

mN

6994000 mN

6990000 mN

6990

000

mN

7000000 mN

6996

000

mN

6996000 mN

6998

000

mN

6998000 mN

316000 mE314000 mE308000 mE 310000 mE 312000 mE

316000 mE308000 mE

7000

000

mN

111111111

222222222

333333333

444444444

555555555

666666666

777777777

888888888999999999

101010101010101010

111111111111111111 121212121212121212131313131313131313

141414141414141414

151515151515151515

Lake Maitland ProjectOutback Ecology Consultants

Soil Sample Locations

Author: G. Donnes

Location : Wiluna WA

Date: 14th Aug 2007

Plan: LM_SS_Map2

0 1km

Scale 1:70,000Projection: GDA94 - MGA51

Perth-

-

Lake Maitland

WILUNA

SIR SAMUEL

Location 250K Map Sheet

Legend( Soil Sample Location

2km

kerry

Text Box

FIGURE 2


10

2.2 Test work and procedures

CSBP Soil and Plant Laboratory conducted analyses on the sampled soils from the 15 sites for

ammonium and nitrate (Scarle 1984), extractable phosphorus and potassium (Colwell 1965; Rayment

and Higginson 1992), extractable sulphur (Blair et al. 1991), and organic carbon (Walkley and Black

1934). Measurements of electrical conductivity (1:5 H2O), soil pH (1:5 H2O and 1:5 CaCl2), were

conducted using the methods described in Rayment and Higginson (1992). Particle size analysis of

the <2mm fraction of selected samples was conducted using the methods described in Rayment and

Higginson (1992). Analysis of the total metal concentrations of surface soils from each site was

conducted by ALS Environmental on an acid digest using ICP-AES.

Soil texture was assessed by OES staff using the procedure described in McDonald et al. (1998). A

measure of soil slaking and dispersive properties (Emerson Aggregate Test) was conducted as

described in McKenzie et al. (2002). Soil strength and the resulting tendency of each material to

hardset was assessed by OES staff using a modified Modulus of Rupture test (Aylmore and Sills

1982; Harper and Gilkes 1994). Measurements of water retention characteristics were conducted on

selected samples at the University of Western Australia using the methods described in McKenzie et

al. (2002).

3.0 RESULTS AND DISCUSSION

3.1 Soil Profile Descriptions

A description of the soil profile morphology at each site has been documented, with a summary of the

measured physical, chemical and morphological parameters tabulated for each site (Sections 3.1.1 –

3.1.15). Individual soil characteristics are then discussed in further detail (Sections 3.2 – 3.3). The

vegetation descriptions given for each site are based on those described in the concurrent Outback

Ecology Vegetation and Flora Baseline Report for the Project Area (OES 2007).


11

3.1.1 Site 1

Site Details: New camp site

Altitude: 449 m

Vegetation association: spinifex / acacia

Plate 1 Soil Profile at Site 1

Plate 2 Vegetation at Site 1

0 – 5 cm: Predominantly single grained,

with some weak polyhedral aggregates, 5 to 40

mm in size. Approximately 5 to 10% sub-angular

and angular coarse fragments, 2 to 5 mm in size.

Roots abundant.

10 – 20 cm: Weak to moderate strength

polyhedral aggregates, 10 to 60 mm in size.

Approximately 10 to 25% sub-angular and

angular coarse fragments, 2 to 20 mm in size,

increasing in abundance with depth. Many roots.



Approximately 25 to 40% sub-angular and

angular coarse fragments, 2 to 40 mm in size.

Roots common.

90 – 100 cm: Predominantly single grained

soil between sub-angular and angular coarse

fragments, 10 to 75 mm in size, increasing in

abundance with depth. Few roots.

Soil surface: Thin platy surface crust, with

approximately 10% cryptogam cover and 5%

litter cover on soil surface. Approximately

10% sub-angular coarse fragments.

Vegetation: Spinifex / acacia complex

(OES 2007), Casuarina sp., with some

Atriplex bunburyana shrubs and grasses.

100cm

0cm

50cm

12

Table 3 Soil physical characteristics for Site 1

Particle size distribution Sample

reference / depth (cm)

Soil Structure Soil Texture % Coarse (>2mm)

% Coarse Sand

% Fine Sand

% Silt % Clay

Penetration Resistance

(MPa)

Bulk Density (g/cm3)

Emerson Test

Class1. MOR (kPa)

Root Score2.

0 to 5 Single grained, some weak aggregates Sandy loam 6.4 50.4 35 4.9 9.7 0.5 1.57 - 9.2 4

10 to 20 Weak to moderate aggregates

Sandy clay loam 8.8 - - - - 1.2 1.52 5 or 6 11.5 3


Sandy clay loam 48.5 47.5 30.6 6.7 15.3 2.3 1.32 5 or 6 16.2 2-3

90 to 100 Single grained between coarse fragments Sandy loam 67.2 66.6 18.5 5 9.9 2.3 - - 4.9 1

1. See Appendix B for Emerson Test class categories. 2. See Appendix F for root growth scoring categories.

Table 4 Soil chemical characteristics for Site 1

Sample reference / depth (cm)

Soil pH

(H2O)

EC

(dS/m)

Org C

(%)

Nitrate

N

(mg/kg)

Amm.

N

(mg/kg)

Avail.

P

(mg/kg)

Avail.

K

(mg/kg)

Avail.

S

(mg/kg)

Fe

(mg/kg)

0 to 5 8.9 0.09 0.63 2 1 5 253 7.7 281

10 to 20 9.3 0.248 0.61 2 1 3 327 16 215

40 to 50 8.6 3.826 0.64 6 1 2 413 757 208

90 to 100 8.8 3.225 0.39 10 1 2 346 471 138


13

3.1.2 Site 2 Site Details: North of new camp site

Altitude: 487 m




0 – 5 cm: Moderate to strong platy

aggregates at surface, 10 to 100 mm in size, with

strong polyhedral aggregates below 3 cm.

Approximately 10% sub-angular coarse

fragments, 2 to 5 mm in size. Many roots.

10 – 20 cm: Moderate strength polyhedral

aggregates, 10 to 100 mm in size. Approximately

10 to 20% sub-angular and sub-rounded coarse

fragments, 2 to 10 mm in size. Roots common.

40 – 50 cm: Predominantly single grained soil

between approximately 60% sub-rounded and

rounded coarse fragments, 2 to 30 mm in size.

Roots common.


between approximately 75% sub-rounded, sub-

angular and angular coarse fragments, 2 to 75

mm in size. Quartz nodules increasing in

abundance from 70 cm depth. Few roots.

Soil surface: Loose sandy surface, with


litter cover on soil surface. Less than 5%

coarse fragments.


(OES 2007), Acacia sp. 2 - 5 m in height.

100cm

0cm

50cm

14





% Coarse Sand

% Fine Sand

% Silt % Clay


(MPa)


Emerson Test

Class1. MOR (kPa)

Root Score2.

0 to 5 Moderate aggregates Clay loam sandy 3.4 49.2 29.3 4.9 16.6 5.8 1.75 5 or 6 36.0 2-3

10 to 20 Moderate aggregates Clay loam sandy

22.8 - - - - 11.2 - 3a 14.3 2-3

40 to 50 Predominantly single grained, some weak

aggregates

Sandy clay loam

47.1 50.8 27.6 3.9 17.7 - - - 3.9 2

90 to 100 Single grained Loamy sand 60.4 - - - - - - - 0.6 1-2




Soil pH

(H2O)

EC

(dS/m)

Org C

(%)

Nitrate

N

(mg/kg)

Amm.

N

(mg/kg)

Avail.

P

(mg/kg)

Avail.

K

(mg/kg)

Avail.

S

(mg/kg)

Fe

(mg/kg)

0 to 5 8 1.363 0.53 17 4 7 181 16.1 574

10 to 20 8.2 0.762 0.26 3 1 2 499 208 500

40 to 50 7.8 2.291 0.22 3 1 2 779 1417 409

90 to 100 8.2 2.62 0.19 3 1 2 716 2442 347


15

3.1.3 Site 3

Site Details: North of new camp site, adjacent to Tony Well

Altitude: 476 m




0 – 5 cm: Moderate strength polyhedral

aggregates, 5 to 100 mm in size. Less than 5%

sub-rounded coarse fragments, 2 to 5 mm in

size. Roots abundant.


with some weak aggregates. Less than 5% sub-

rounded and rounded coarse fragments, 2 to 5

mm in size. Roots abundant.


with some weak aggregates. Approximately 5%

sub-rounded and rounded coarse fragments, 2 to

5 mm in size. Many roots.

90 – 100 cm: Predominantly massive structure

with firm consistence. Approximately 5% sub-

rounded and rounded coarse fragments, 2 to 5

mm in size. Roots common.

Soil surface: Loose sandy surface, with 5

to 10 % cryptogam cover and 10% litter cover

on soil surface. Less than 5% coarse

fragments.


(OES 2007), Acacia sp. to 5 m in height, and

spinifex grasses.

100cm

0cm

50cm

16





% Coarse Sand

% Fine Sand

% Silt % Clay


(MPa)


Emerson Test

Class1. MOR (kPa)

Root Score2.

0 to 5 Moderate aggregates Clay loam sandy 1.9 63.5 27.4 1 8.1 2.0 1.52 3b 8.5 4

10 to 20 Single grained, some weak aggregates

Clay loam sandy 22.8 - - - - 0.8 1.67 - 4.4 4


Sandy clay loam 47.1 59.4 27.2 4.8 8.6 2.2 1.72 - 3.4 3

90 to 100 Massive Loamy sand 60.4 - - - - 5.8 - - 6.5 2-3




Soil pH

(H2O)

EC

(dS/m)

Org C

(%)

Nitrate

N

(mg/kg)

Amm.

N

(mg/kg)

Avail.

P

(mg/kg)

Avail.

K

(mg/kg)

Avail.

S

(mg/kg)

Fe

(mg/kg)

0 to 5 5.5 0.02 0.54 2 2 2 93 8.4 593

10 to 20 5.4 0.03 0.25 3 1 2 113 24.4 680

40 to 50 5.7 0.023 0.23 3 1 2 87 13.9 629

90 to 100 5.9 0.127 0.21 3 1 2 129 10.1 671


17

3.1.4 Site 4

Site Details: Northeast of new camp site

Altitude: 478 m

Vegetation association: spinifex



0 – 5 cm: Moderate strength platy

aggregates at surface, 5 to 100 mm in size, with

polyhedral aggregates below 2 to 3 cm.

Approximately 5% sub-angular and sub-rounded

coarse fragments, 2 to 5 mm in size. Roots

abundant.

10 – 20 cm: Weak polyhedral aggregates, 10

to 50 mm in size. Approximately 5 to 10% sub-

angular and sub-rounded coarse fragments, 2 to

10 mm in size. Many roots.


with some weak aggregates. Approximately 10 to

20% sub-angular and sub-rounded calcareous

coarse fragments, 2 to 10 mm in size, increasing

in abundance with depth. Roots common.



angular and sub-rounded calcareous coarse

fragments, 2 to 100 mm in size. Few roots.

Soil surface: Loose sandy surface, aeolian

deposition over a platy crust, with less than

5% cryptogam cover and 2% litter cover on

soil surface. Less than 5% coarse fragments.

Vegetation: Spinifex complex (OES 2007).

The majority of vegetation has been burnt,

with some remnants of spinifex and tree

species, approx 3.5 m height.

100cm

0cm

50cm

18





% Coarse Sand

% Fine Sand

% Silt % Clay


(MPa)


Emerson Test

Class1. MOR (kPa)

Root Score2.

0 to 5 Moderate aggregates Clayey sand 3.3 65 22.2 2 10.9 1.8 1.62 5 or 6 7.8 3-4

10 to 20 Weak aggregates Sandy clay loam 6.2 - - - - 0.9 1.69 - 9.5 3


Clay loam sandy 10.1 47.1 26.4 1 25.5 1.1 1.75 - 8.9 2-3

90 to 100 Massive Light medium clay 6.4 - - - - 6.0 - - 31.5 1




Soil pH

(H2O)

EC

(dS/m)

Org C

(%)

Nitrate

N

(mg/kg)

Amm.

N

(mg/kg)

Avail.

P

(mg/kg)

Avail.

K

(mg/kg)

Avail.

S

(mg/kg)

Fe

(mg/kg)

0 to 5 6.1 0.019 0.33 3 1 2 68 3.7 534

10 to 20 6.2 0.021 0.32 3 1 2 98 8.1 576

40 to 50 6.5 0.012 0.26 3 1 2 104 3.8 566

90 to 100 7.2 0.032 0.24 3 1 2 164 9.9 620


19

3.1.5 Site 5

Site Details: Northeast of new camp site

Altitude: 478 m




0 – 5 cm: Weak platy polyhedral

aggregates, 10 to 50 mm in size. Approximately

5% sub-rounded coarse fragments, 2 to 5 mm in

size. Many roots.

10 – 20 cm: Weak polyhedral aggregates, 10

to 50mm in size. Approximately 10% sub-angular

and sub-rounded coarse fragments, 2 to 5 mm in

size. Many roots.


with some very weak aggregates. Approximately

25% sub-angular and sub-rounded calcareous

coarse fragments, 2 to 10 mm in size, increasing

in abundance with depth. Roots common.



angular and sub-rounded calcareous coarse

fragments, 2 to 40 mm in size, increasing in

abundance with depth. Few roots.

Soil surface: Loose sandy surface, aeolian

deposition over a platy crust, with less than 5%

cryptogam cover and 2% litter cover on soil

surface. Less than 2% coarse fragments.


The majority of vegetation has been burnt, with

some remnants of spinifex and Acacia.

100cm

0cm

50cm

20





% Coarse Sand

% Fine Sand

% Silt % Clay


(MPa)


Emerson Test

Class1. MOR (kPa)

Root Score2.

0 to 5 Weak aggregates Clayey sand 2.4 68.9 19.8 1 8.4 1.1 1.63 3b 7.2 3

10 to 20 Weak aggregates Sandy loam 2.9 - - - - 0.8 1.61 - 13.8 2-3

40 to 50 Single grained, some weak aggregates Sandy loam 7.3 48.8 32.1 1 17.2 1.0 1.72 - 6.7 2

90 to 100 Massive Sandy clay loam 50.7 - - - - 4.1 - - 16.3 1-2




Soil pH

(H2O)

EC

(dS/m)

Org C

(%)

Nitrate

N

(mg/kg)

Amm.

N

(mg/kg)

Avail.

P

(mg/kg)

Avail.

K

(mg/kg)

Avail.

S

(mg/kg)

Fe

(mg/kg)

0 to 5 6.7 0.063 0.28 3 1 2 104 55.3 543

10 to 20 6.7 0.03 0.27 3 1 2 116 15.8 554

40 to 50 6.4 0.011 0.22 2 1 2 114 8.4 528

90 to 100 6.4 0.024 0.22 3 1 2 118 14 589


21

3.1.6 Site 6

Site Details: South of new camp site

Altitude: 479 m




0 – 5 cm: Weak to moderate strength platy

polyhedral aggregates, 10 to 100 mm in size. Less

than 5% sub-rounded and rounded coarse

fragments, 2 to 5 mm in size. Roots abundant.

10 – 20 cm: Moderate polyhedral aggregates,

20 to 150 mm in size. Less than 5% sub-rounded

and rounded coarse fragments, 2 to 5 mm in size.

Many roots.


with some weak aggregates. Approximately 10%

sub-rounded and rounded coarse fragments, 2 to

10 mm in size. Roots common.



rounded and rounded coarse fragments,

increasing slightly with depth, 2 to 10 mm in size.

Platy calcrete layer at base. Few roots.

Soil surface: Platy surface crust with some

sandy patches, 40 % cryptogam cover and 10

% litter cover on soil surface. Less than 5 %

coarse fragments.


(OES 2007). Acacia sp. 2 - 5 m in height, with

spinifex and other grasses.

100cm

0cm

50cm

22





% Coarse Sand

% Fine Sand

% Silt % Clay


(MPa)


Emerson Test

Class1. MOR (kPa)

Root Score2.


Sandy clay loam 1.9 50.4 27.6 1 21 1.8 1.63 5 or 6 5.9 3-4

10 to 20 Moderate aggregates Sandy clay loam 2.7 - - - - 1.7 1.5 5 or 6 3.6 3

40 to 50 Single grained, some weak aggregates Sandy loam 3.1 53.6 24 1 21.4 3.8 1.65 - 6.0 2

90 to 100 Massive Clay loam sandy 7.3 - - - - 8.7 - - 11.1 1




Soil pH

(H2O)

EC

(dS/m)

Org C

(%)

Nitrate

N

(mg/kg)

Amm.

N

(mg/kg)

Avail.

P

(mg/kg)

Avail.

K

(mg/kg)

Avail.

S

(mg/kg)

Fe

(mg/kg)

0 to 5 5.3 0.026 0.43 3 3 6 151 5.9 507

10 to 20 4.9 0.042 0.31 3 1 2 124 19.9 549

40 to 50 5.7 0.017 0.22 3 1 2 159 9.5 529

90 to 100 6.1 0.125 0.24 3 1 2 159 55.2 448


23

3.1.7 Site 7

Site Details: South of new camp site, adjacent to Two Jacks well

Altitude: 475 m




0 – 5 cm: Weak to moderate strength platy

and polyhedral aggregates, 20 to 75 mm in size.

Less than 5% sub-rounded and rounded coarse

fragments, 2 to 5mm in size. Roots abundant.


with some moderate polyhedral aggregates, 20 to

50 mm in size. Less than 5% sub-rounded and


Many roots.


with firm consistence. Approximately 40 to 60%

sub-rounded and sub-angular coarse fragments,

2 to 30 mm in size. Roots common.

90 – 100 cm: Predominantly single grained.

Approximately 60% sub-rounded and sub-angular

coarse fragments, 2 to 30 mm in size. Few roots.

Soil surface: Predominantly sandy surface,

with 5 to 10% cryptogam cover and 5% litter

cover. Less than 5% coarse fragments.


Dominated by Eucalyptus. and spinifex

grasses, with some Acacia.

100cm

0cm

50cm

24





% Coarse Sand

% Fine Sand

% Silt % Clay


(MPa)


Emerson Test

Class1. MOR (kPa)

Root Score2.

0 to 5 Weak to moderate aggregates Clayey sand 4.6 67.4 19.7 2 10.9 1.5 1.73 3b 5.6 3-4

10 to 20 Massive, some moderate aggregates

Sandy clay loam 11.1 - - - - 14.3 1.59 - 4.6 3

40 to 50 Massive Clay loam sandy 11.2 54.2 24.3 3.9 17.6 13.3 - - 1.8 2

90 to 100 Single grained Clayey sand 41.4 - - - - 1.8 - - 1.9 1




Soil pH

(H2O)

EC

(dS/m)

Org C

(%)

Nitrate

N

(mg/kg)

Amm.

N

(mg/kg)

Avail.

P

(mg/kg)

Avail.

K

(mg/kg)

Avail.

S

(mg/kg)

Fe

(mg/kg)

0 to 5 5.3 0.076 0.25 3 1 2 73 34.1 521

10 to 20 6.1 0.346 0.27 3 1 2 96 210 512

40 to 50 6.3 0.192 0.24 3 1 2 128 50.5 472

90 to 100 7.8 1.42 0.17 15 1 2 179 1362 237


25

3.1.8 Site 8

Site Details: Lake playa

Altitude: 471 m

Vegetation association: lake playa



0 – 5 cm: Thin platy crust, with weak to

moderate strength polyhedral aggregates below,

10 to 50mm in size. Less than 5% sub-angular and

sub-rounded coarse fragments, 2 to 5 mm in size.

Many roots.





common.





common.

90 – 100 cm: Predominantly single grained, with

some weak aggregates. Approximately 5 to 10%

sub-rounded and rounded coarse fragments, 2 to 5

mm in size. Few roots, water table at 110 cm.

Soil surface: Thin platy clay surface crust,

with some “sandy” lenses. 40 to 50 %

cryptogam cover and 5 % litter cover. Less

than 2 % coarse fragments.

Vegetation: Lake playa complex (OES

2007). Dominated by Halosarcia.

100cm

0cm

50cm

26





% Coarse Sand

% Fine Sand

% Silt % Clay


(MPa)


Emerson Test

Class1. MOR (kPa)

Root Score2.

0 to 5 Weak to moderate aggregates Sandy loam 0.0 45.7 16.8 34.5 3.0 - 0.95 5 or 6 4.6 3-4


Sandy clay loam 0.0 - - - - - 1.07 5 or 6 16.2 2

40 to 50 Weak to moderate aggregates Light clay 1.8 31.7 27.0 34.5 6.8 - 0.91 - 71.4 1-2

90 to 100 Weak aggregates Clay loam sandy 15.0 32.0 20.3 37.3 10.5 - - - 60.0 1




Soil pH

(H2O)

EC

(dS/m)

Org C

(%)

Nitrate

N

(mg/kg)

Amm.

N

(mg/kg)

Avail.

P

(mg/kg)

Avail.

K

(mg/kg)

Avail.

S

(mg/kg)

Fe

(mg/kg)

0 to 5 8.2 4.088 0.53 9 1 36 243 4194 683

10 to 20 8.1 8.1 0.56 24 1 7 520 5950 418

40 to 50 8.2 9.999 0.55 30 1 3 930 7245 377

90 to 100 8.2 9.999 0.55 46 1 2 1169 7901 292


27

3.1.9 Site 9


Altitude: 471 m




0 – 5 cm: Thin platy crust, predominantly

single grained below, with coarse crystalline

material and clayey aggregates. Less than 5%

coarse fragments. Roots abundant.


with coarse crystalline material and clayey

aggregates. Less than 5% coarse fragments.

Roots common.

40 – 50 cm: Moderate clay aggregates, with

“sandy” crystalline lenses. Less than 5% coarse

fragments. Few roots.

90 – 100 cm: Moderate clay aggregates, with

“sandy” crystalline lenses. Less than 5% coarse

fragments. Few roots, water table at 110 cm.


with some “sandy” lenses. 75% cryptogam

cover and 5 % litter cover. Approximately 5 %

coarse fragments.


2007). Dominated by Halosarcia sp., with

some grass species.

100cm

0cm

50cm

28





% Coarse Sand

% Fine Sand

% Silt % Clay


(MPa)


Emerson Test

Class1. MOR (kPa)

Root Score2.

0 to 5 Platy surface crust / single grained Clayey sand 0.5 46.3 36.0 14.6 3.1 0.2 0.95 - 19.2 3-4

10 to 20 Single grained Loam 0.8 - - - - 0.3 1.24 5 or 6 59.0 2

40 to 50 Moderate clay aggregates Loam 0.0 23.0 58.4 12.5 6.2 1.5 - 5 or 6 64.7 1-2

90 to 100 Moderate clay aggregates

Light medium clay 0.0 16.2 32.5 44.8 6.5 0.9 - - 94.3 0-1




Soil pH

(H2O)

EC

(dS/m)

Org C

(%)

Nitrate

N

(mg/kg)

Amm.

N

(mg/kg)

Avail.

P

(mg/kg)

Avail.

K

(mg/kg)

Avail.

S

(mg/kg)

Fe

(mg/kg)

0 to 5 8.4 4.14 0.53 3 1 13 231 5224 381

10 to 20 8.2 4.04 0.28 6 1 9 206 5726 175

40 to 50 8.3 6.26 0.33 16 1 5 382 7360 192

90 to 100 8.2 9.99 0.44 38 1 3 966 7050 385


29

3.1.10 Site 10

Site Details: Adjacent to bag farm

Altitude: 473 m

Vegetation association: calcrete



0 – 5 cm: Weak polyhedral aggregates,

10 to 40mm in size. Approximately 10%

polyhedral coarse fragments, 2 to 40 mm in

size. Roots abundant.


with some weak aggregates. Approximately

10% polyhedral coarse fragments, 2 to 40 mm

in size, increasing with abundance at depth.

Calcareous nodules at 30 cm. Many roots.

Soil surface: Platy surface crust,


litter cover on soil surface. Approximately 30 %

coarse fragments.

Vegetation: Calcrete complex (OES 2007).

Dominated by shrubs and grasses, with some

Frankia sp.

0cm

10cm

30cm

20cm

30





% Coarse Sand

% Fine Sand

% Silt % Clay


(MPa)


Emerson Test

Class1. MOR (kPa)

Root Score2.

0 to 5 Weak aggregates Sandy loam 14.3 33.8 40.7 10.8 14.7 1.3 1.35 8 9.8 3-4

10 to 20 Single grained, some weak aggregates Light clay 17.9 - - - - 2.5 1.34 - 21.0 3




Soil pH

(H2O)

EC

(dS/m)

Org C

(%)

Nitrate

N

(mg/kg)

Amm.

N

(mg/kg)

Avail.

P

(mg/kg)

Avail.

K

(mg/kg)

Avail.

S

(mg/kg)

Fe

(mg/kg)

0 to 5 8.6 0.659 0.65 3 1 2 222 1158 266

10 to 20 8.4 0.762 0.64 2 1 3 373 286 224


31

3.1.11 Site 11

Site Details: North of bag farm

Altitude: 468 m




with some weak polyhedral aggregates, 10 to

40 mm in size. Approximately 5 to 10% sub-


Roots abundant.


material. Approximately 10% sub-rounded

coarse fragments, 2 to 40 mm in size. Many

roots.


material. Approximately 50% sub-rounded

coarse fragments, 2 to 50 mm in size,

increasing in abundance with depth from 40

cm. Roots common.



litter cover on soil surface. Approximately

30% coarse fragments.

Vegetation: Calcrete complex (OES

2007). Predominantly grasses, with some

Roly Poly (Salsola tragus), Mariana. and

Acacia.

No image available

32





% Coarse Sand

% Fine Sand

% Silt % Clay


(MPa)


Emerson Test

Class1. MOR (kPa)

Root Score2.

0 to 5 Single grained, some weak aggregates Sandy loam 14.3 34.3 43.4 8.8 13.6 0.8 1.42 - 15.8 4

10 to 20 Single grained Sandy loam 41.8 - - - - 1.4 - - 7.8 3-4

40 to 50 Single grained Sandy clay loam 36.2 27.6 31.4 16.2 24.8 0.5 - - 78.6 2




Soil pH

(H2O)

EC

(dS/m)

Org C

(%)

Nitrate

N

(mg/kg)

Amm.

N

(mg/kg)

Avail.

P

(mg/kg)

Avail.

K

(mg/kg)

Avail.

S

(mg/kg)

Fe

(mg/kg)

0 to 5 8.9 0.135 0.69 2 1 2 196 28.8 223

10 to 20 8.1 2.095 0.71 6 1 6 221 5629 182

40 to 50 8.6 2.325 0.61 10 1 2 342 143 124


33

3.1.12 Site 12


Altitude: 514 m





with coarse crystalline material. Less than 2%

coarse fragments, 2 to 5 mm. Roots common.


20 to 50 mm in size. Less than 2% coarse



20 to 50 mm in size. Les than 2% coarse



with some sandy lenses. Approximately 50%

cryptogam cover and 5% litter cover. Less

than 2% coarse fragments.


2007). Dominated by Halosarcia.

0cm

10cm

20cm

34





% Coarse Sand

% Fine Sand

% Silt % Clay


(MPa)


Emerson Test

Class1. MOR (kPa)

Root Score2.

0 to 5 Single grained Clayey sand 0.7 59.9 24.6 10.3 5.1 0.2 0.93 - 7.3 2

10 to 20 Moderate aggregates Clay loam 0.0 19.5 48.0 27.4 5.0 0.9 1.1 5 or 6 106.8 1

40 to 50 Moderate aggregates Light clay 0.0 20.3 45.9 28.8 4.9 - - - 28.8 1




Soil pH

(H2O)

EC

(dS/m)

Org C

(%)

Nitrate

N

(mg/kg)

Amm.

N

(mg/kg)

Avail.

P

(mg/kg)

Avail.

K

(mg/kg)

Avail.

S

(mg/kg)

Fe

(mg/kg)

0 to 5 8.4 2.608 0.41 2 1 9 108 6128 203

10 to 20 8.3 3.95 0.38 7 1 3 337 6599 377

40 to 50 8.2 6.596 0.38 12 1 2 562 6832 282


35

3.1.13 Site 13

Site Details: North of bag farm

Altitude: 474 m




0 – 5 cm: Polyhedral aggregates in the

top 5 cm, 10 to 40 mm in size, with

predominantly single grained material below.

Approximately 10% sub-angular and sub-


Roots abundant.


material. Approximately 60% sub-angular and

sub-rounded coarse fragments, 2 to 50 mm in

size, increasing in abundance with depth from

30 cm. Many roots.



litter cover on soil surface. Approximately 5%

coarse fragments.

Vegetation: Calcrete complex (OES 2007).

Dominated by Casuarina and grasses, with

some Mariana and Acacia.

0cm

10cm

20cm

36





% Coarse Sand

% Fine Sand

% Silt % Clay


(MPa)


Emerson Test

Class1. MOR (kPa)

Root Score2.

0 to 5 Weak aggregates to single grained below Clay loam 14.3 23.7 50.3 10.6 15.4 0.9 1.32 2 26.2 4

10 to 20 Single grained Clay loam sandy 24.6 - - - - 1.0 - - 10.9 3




Soil pH

(H2O)

EC

(dS/m)

Org C

(%)

Nitrate

N

(mg/kg)

Amm.

N

(mg/kg)

Avail.

P

(mg/kg)

Avail.

K

(mg/kg)

Avail.

S

(mg/kg)

Fe

(mg/kg)

0 to 5 8.9 0.485 0.65 3 1 6 400 773 279

10 to 20 9.2 0.344 0.68 3 1 2 590 321 231


37

3.1.14 Site 14

Site Details: South of new camp site, on dune, east of lake playa

Altitude: 480 m





material, with a thin layer (0 - 2 cm) of soil at

surface, gypsum below. Approximately 5%

sub-angular and sub-rounded coarse

fragments, 2 to 5 mm in size. Roots common.


material. Approximately 5% sub-angular and

sub-rounded coarse fragments, 2 to 5 mm.

Few roots.

Soil surface: Thin surface crust, with


litter cover on soil surface. Approximately 5%

coarse fragments.

Vegetation: Spinifex / acacia complex /

kopi (OES 2007). Dominated by Senna and

grasses, with some Frankenia.

0cm

10cm

30cm

20cm

38





% Coarse Sand

% Fine Sand

% Silt % Clay


(MPa)


Emerson Test

Class1. MOR (kPa)

Root Score2.

0 to 5 Single grained Sandy loam 7.7 34.8 37.8 18.6 8.8 0.5 0.98 - 18.6 2

10 to 20 Single grained, some weak aggregates Clay loam 6.7 - - - - 1.0 - 4 7.6 1




Soil pH

(H2O)

EC

(dS/m)

Org C

(%)

Nitrate

N

(mg/kg)

Amm.

N

(mg/kg)

Avail.

P

(mg/kg)

Avail.

K

(mg/kg)

Avail.

S

(mg/kg)

Fe

(mg/kg)

0 to 5 8.5 1.998 0.41 3 1 8 36 5787 24

10 to 20 8.3 2.315 0.41 3 1 4 72 6174 0


39

3.1.15 Site 15

Site Details: West of new camp site, edge of lake playa

Altitude: 469 m

Vegetation association: lake playa / calcrete



0 – 5 cm: Moderate to strong platy and


Approximately 20% sub-angular and sub-

rounded coarse fragments, 2 to 40 mm in

size. Many roots.


soil, approximately 50% sub-rounded and

sub-angular coarse fragments, 2 to 60 mm in

size. Coarse fragments increasing in

abundance from 15 cm depth. Roots common.

Soil surface: Thin surface crust, with 40%

cryptogam cover and 5 % litter cover on soil

surface. Approximately 10% coarse

fragments.

Vegetation: Edge of calcrete and lake

playa complex (OES 2007). Predominantly

Acacia and grasses.

0cm

10cm

20cm

40





% Coarse Sand

% Fine Sand

% Silt % Clay


(MPa)


Emerson Test

Class1. MOR (kPa)

Root Score2.

0 to 5 Moderate aggregates Sandy loam 13.6 49.1 34.1 4.9 11.8 3.4 1.62 3b 9.2 3

10 to 20 Single grained between coarse fragments

Sandy clay loam 56.0 - - - - 2.1 - - 18.6 2




Soil pH

(H2O)

EC

(dS/m)

Org C

(%)

Nitrate

N

(mg/kg)

Amm.

N

(mg/kg)

Avail.

P

(mg/kg)

Avail.

K

(mg/kg)

Avail.

S

(mg/kg)

Fe

(mg/kg)

0 to 5 8.7 0.975 0.56 3 1 4 111 912 171

10 to 20 8.8 0.159 0.75 3 1 4 148 128 213


41

3.2 Soil Chemical Properties

3.2.1 Soil pH

The soil pH gives a measure of the soil acidity or alkalinity. The ideal pH range for plant growth of

most agricultural species is considered to be between 5.0 and 7.5 (Moore, 1998). Outside of this

range, the plant-availability of some nutrients is affected, while various metal toxicities (e.g. Al and Mn)

can become limiting to plant growth at low pH. For native species, which are known to be tolerant of

wider ranges in soil pH, preferred pH ranges are best inferred from the soil in which they are observed

to occur.

There was a broad range of pH values measured within the soils of the study area, with values

reflecting the variation and complexity of the soils sampled. Values ranged between pH (H2O) 4.9 to

9.3 (Figure 3). The majority of soil materials sampled were classed from moderately acid to

moderately alkaline (Moore 1998). The most acidic pH levels were found at the spinifex and some

spinifex / acacia sites, notably Sites 3, 6 and 7. Alkaline pH levels were more common within the lake

playa and calcrete sites, notably sites 8 to 15. Sites 1 and 2, both spinifex / acacia complex, were

found to be neutral to moderately alkaline.

Soil pH in the spinifex / acacia and spinifex association sites increased slightly with depth. Conversely,

the calcrete and lake playa sites typically had little change in soil pH with depth.

Figure 3 Individual and average soil pH (H2O) values grouped into spinifex / acacia, spinifex, lake playa and calcrete sites (Error bars represent standard error).

0

20

40

60

80

100

4 6 8 10

pH (H2O)

Dep

th (c

m)

spinifex/acacia spinifex lake playa calcrete

0

20

40

60

80

100

4 6 8 10

Average pH (H2O)

spinifex/acacia spinifex

lake playa calcrete


42

3.2.2 Electrical Conductivity

Electrical conductivity is a measure of the soluble salts in soils or water. Soil salinity results from

natural processes of landscape evolution, hydrological processes and rainfall (Hunt and Gilkes, 1992).

The electrical conductivity (EC) of the soils within the study area varied greatly, ranging between

0.011 and 9.99 dS/m (Figure 4). Most sites fell into one of two categories, ‘non-saline’ or ‘extremely

saline’, based on the standard USDA and CSIRO categories (Appendix E). Sites that were

considered to be extremely saline were Sites 1 and 2 (spinifex / acacia), Sites 8, 9, 12 and 15 (lake

playa), plus Sites 10, 11 and 13 (calcrete). Sites 3 and 6 (spinifex / acacia), and Sites 4, 5 and 7

(spinifex) were considered to be non-saline. The salinity levels appear more dependent on the

proximity of the sample sites to the lake, rather than soil / vegetation associations.

As would be expected, the average electrical conductivity was greatest within the sites on the lake

playa.

Figure 4 Individual and average electrical conductivity (EC 1:5 H2O) values grouped into spinifex / acacia, spinifex, lake playa and calcrete sites (Error bars represent standard error).

3.2.3 Soil Organic Matter

The organic matter content of a soil is an important factor influencing many physical, chemical and

biological soil characteristics. It is directly derived from plants and animals and its functions in soil

0

20

40

60

80

100

0 2 4 6 8 10 12

Electrical Conductivity (dS/m)

Dep

th (c

m)


0

20

40

60

80

100

0 2 4 6 8 10 12

Average Electrical Conductivity (dS/m)


lake playa calcrete


43

include supporting the micro and macro-organisms in the soil, increasing the water retention capacity

of the soil, buffering pH and improving soil structure.

The amount of organic carbon within the majority of the soils sampled was low, as is the case in many

natural Western Australian soils (Figure 5). The highest average organic carbon contents were

measured in the surface soils of the calcrete and lake playa areas, with spinifex and spinifex / acacia

sites recording lower values. As would be expected the level of soil organic carbon typically

decreased with depth.

Figure 5 Individual and average soil organic carbon (%) values grouped into spinifex / acacia, spinifex, lake playa and calcrete sites (Error bars represent standard error).

3.2.4 Soil Nutrients

The most important macro-nutrients for plant growth are nitrogen (N), phosphorus (P), potassium (K),

and sulphur (S). These nutrients are largely derived from the soil and organic matter. While the

definition of adequate levels of these nutrients are well known for agricultural species, relatively little

information is available for the nutrient requirements of native species.

The amount of plant available nutrients held within the soils sampled was variable (Figures 6 to 10).

For nitrogen and phosphorus, concentrations for most sites were low (nitrogen < 8 mg/kg, phosphorus

< 10 mg/kg), which is a typical of native arid Australian soils (Figure 7, Figure 8). The exception was

0

20

40

60

80

100

0.0 0.2 0.4 0.6 0.8 1.0

Organic Carbon (%)

Dep

th (c

m)


0

20

40

60

80

100

0.0 0.2 0.4 0.6 0.8 1.0

Average organic carbon (%)


lake playa calcrete


44

the lake playa sites, which had relatively high concentrations of available nitrate, phosphorus,

potassium and sulphur in comparison to surrounding sites.

Figure 6 Individual and average nitrate N (mg/kg) values grouped into spinifex / acacia, spinifex, lake playa and calcrete sites (Error bars represent standard error).

Figure 7 Individual and average ammonium N (mg/kg) values grouped into spinifex / acacia, spinifex, lake playa and calcrete sites (Error bars represent standard error).

0

20

40

60

80

100

0 10 20 30 40 50

Nitrate (mg/kg)

Dep

th (c

m)

acacia/spinifex spinifex lake playa calcrete

0

20

40

60

80

100

0 10 20 30 40 50

Average nitrate (mg/kg)

acacia/spinifex spinifexlake playa calcrete

0

20

40

60

80

100

0.0 1.0 2.0 3.0 4.0 5.0

Ammonium (mg/kg)

Dep

th (c

m)


0

20

40

60

80

100

0.0 1.0 2.0 3.0 4.0 5.0

Average ammonium (mg/kg)


lake playa calcrete


45

Figure 8 Individual and average extractable phosphorus (P) (mg/kg) values grouped into spinifex / acacia, spinifex, lake playa and calcrete sites (Error bars represent standard error).

Figure 9 Individual and average extractable potassium (K) (mg/kg) values grouped into spinifex / acacia, spinifex, lake playa and calcrete sites (Error bars represent standard error).

0

20

40

60

80

100

0 5 10 15 20

Phosphorus (mg/kg)

Dep

th (c

m)


0

20

40

60

80

100

0 5 10 15 20

Average phosphorus (mg/kg)

acacia/spinifex spinifex

lake playa calcrete

0

20

40

60

80

100

0 200 400 600 800 1000 1200

Potassium (mg/kg)

Dep

th (c

m)


0

20

40

60

80

100

0 200 400 600 800 1000 1200

Average potassium (mg/kg)


lake playa calcrete


46

Figure 10 Individual and average extractable sulphur (S) (mg/kg) values grouped into spinifex/acacia, spinifex, lake playa and calcrete sites (Error bars represent standard error).

3.2.5 Heavy Metals Measurements of total metal concentrations of surface samples indicated that only very low levels of

As, Cd, Cr, Cu, Pb, Ni, Zn and Hg were present (Table 33). Many materials sampled were below the

detectable limit for As, Cd, Pb, Zn and Hg, with only Cr, Cu and Ni regularly detected at a reportable

level. Low levels of As were measured in some of the lake playa soils, however, for the remaining

metals detected, there was no apparent correlation with landform / vegetation association.

0

20

40

60

80

100

0 2000 4000 6000 8000

Sulphur (mg/kg)

Dep

th (c

m)


0

20

40

60

80

100

0 2000 4000 6000 8000

Average sulphur (mg/kg)


lake playa calcrete

47

Table 33 Individual total metal values (mg/kg) for selected soil horizons at all sites.

Analyte (mg/kg) Site Depth Soil / veg

complex Arsenic Cadmium Chromium Copper Lead Nickel Zinc Mercury S1 0-5 <5 <1 44 6 <5 8 10 <0.1 S1 40-50 <5 <1 12 9 <5 4 <5 <0.1 S1 90-100

spinifex acacia <5 <1 13 9 <5 3 <5 <0.1

S2 0-5 <5 <1 50 8 <5 4 7 <0.1 S2 40-50 spinifex acacia <5 <1 51 12 8 11 7 <0.1 S3 0-5 <5 <1 50 <5 <5 2 <5 <0.1 S3 40-50 <5 <1 55 <5 <5 3 <5 <0.1 S3 90-100

spinifex acacia <5 <1 62 <5 <5 5 <5 <0.1

S4 0-5 <5 <1 65 <5 <5 4 <5 <0.1 S4 40-50 spinifex <5 <1 66 6 <5 6 <5 <0.1 S5 0-5 <5 <1 52 <5 <5 2 <5 <0.1 S5 40-50 <5 <1 61 <5 <5 4 <5 <0.1 S5 90-100

spinifex <5 <1 77 8 8 7 <5 <0.1

S6 0-5 <5 <1 43 6 <5 3 6 <0.1 S6 40-50 spinifex acacia <5 <1 49 6 6 4 <5 <0.1 S7 0-5 <5 <1 48 <5 <5 2 <5 <0.1 S7 40-50 <5 <1 45 6 5 4 <5 <0.1 S7 90-100

spinifex <5 <1 36 6 9 4 <5 <0.1

S8 0-5 <5 <1 24 6 <5 5 10 <0.1 S8 40-50 6 <1 16 <5 <5 4 <5 <0.1 S8 90-100

lake playa <5 <1 13 <5 <5 2 <5 <0.1

S9 0-5 <5 <1 9 <5 <5 <2 <5 <0.1 S9 40-50 <5 <1 11 <5 <5 <2 <5 <0.1 S9 90-100

lake playa 7 <1 18 <5 <5 3 <5 <0.1

S10 0-5 calcrete <5 <1 37 9 <5 5 8 <0.1 S11 0-5 <5 <1 42 9 <5 5 10 <0.1 S11 40-50 calcrete 8 <1 20 6 <5 6 <5 <0.1 S12 0-5 <5 <1 6 <5 <5 <2 <5 <0.1 S12 10-20 6 <1 12 <5 <5 <2 <5 <0.1 S12 40-50

lake playa 14 <1 25 6 <5 4 5 <0.1

S13 0-5 calcrete <5 <1 47 10 5 7 16 <0.1 S14 0-5 spinifex acacia <5 <1 9 <5 <5 <2 <5 <0.1 S15 0-5 lake playa <5 <1 41 <5 <5 3 8 <0.1


48

3.3 Soil Physical Properties

3.3.1 Soil Profile Morphology The surface soil profiles within the study area exhibited a large degree of variation in terms of

morphological characteristics. Soil profiles grouped within the landform / vegetation associations were

generally consistent in depth and organisation of soil layers.

3.3.2 Soil Texture

Soil texture describes the proportions of sand, silt and clay (the particle size distribution), with the

resulting textural class being an important factor influencing most physical and many chemical and

biological properties in soils. Properties such as soil structure, water holding capacity, hydraulic

conductivity, soil strength, fertility, erodibility and susceptibility to compaction are some of the factors

closely linked to soil texture.

There was a broad range of soil textures exhibited at the Lake Maitland study area within the

individual soil profiles, and between sites, with soil textures ranging from loamy sand (approximately 5

% clay) to light medium clay (approximately 40 – 45 % clay). The majority of soil materials were

classed either as a clayey sand, sandy loam, sandy clay loam or clay loam sandy. In general, surface

materials for all sites were found to be coarse in texture, with most sites exhibiting an increase in clay

content with sample depth (Appendix C). The finer textured soils found on the lake playa exhibited

relatively high percentages of silt-sized soil particles. The percentage of coarse material (> 2 mm)

was variable and consistently increased with depth at most sites.

Characteristics of sandy soils include a poor water-holding capacity, but potentially-higher infiltration

and drainage. High infiltration capacity will enhance these soils’ resistance to erosion in high intensity

rainfall events. Loamy soils typically have a moderate water-holding capacity and greater capacity to

hold and supply nutrients, therefore providing greater potential for plant growth. Clay soils generally

have slow water penetration and drainage and can form a ‘crust’ on the surface, therefore preventing

seedlings from emerging and reducing water infiltration.

3.3.3 Soil Structure

Soil structure describes the arrangement of solid particles and void space in a soil. It is an important

factor influencing the ability of soil to support plant growth, store and transmit water and resist

erosional processes. A well-structured soil is one with a range of different sized aggregates, with

component particles bound together to give a range of pore sizes facilitating root growth and the

transfer of air and water.


49

Soil structure can be influenced by the particle size distribution, chemical composition and organic

matter content of a soil, and is often affected by root growth and vehicle compaction. In reconstructed

soil profiles, the methods of soil handling and deposition are important to the structure of

reconstructed soil profiles. When a soil material is disturbed, the breakdown of aggregates into

primary particles can lead to structural decline (Needham et al. 1998). This can result in hard-setting

and crusting at the soil surface and a ‘massive’ soil structure at depth, potentially reducing the ability

of seeds to germinate, roots to penetrate the soil matrix and water to infiltrate to the root zone.

There were a wide range of soil structures identified throughout the sample sites at Lake Maitland,

with soils ranging from coarse, single-grained materials with weak consistence, to well-structured soils

with moderate to strong aggregates, to massive soils with a firm to strong consistence.

3.3.4 Structural Stability

The structural stability of a soil and its susceptibility to structural decline is complex and depends on

the net effect of a number of properties, including the amount and type of clay present, organic matter

content, soil chemistry and the nature of disturbance. A well-structured soil has fractures and pores

which allow water, air and roots to enter the soil easily. Two soil properties which can lead to loss of

structure are slaking and dispersion. Slaking is a process by which aggregated particles in a

structured soil will collapse during wetting, breaking down to leave primary particles and micro-

aggregates, because they have insufficient strength to resist the stresses caused by rapid-water

intake (Needham et al., 1998).

In dispersive soils, clay particles swell in the presence of water, and individual clay layers disperse

into the soil solution. This reaction is principally due to a dominance of sodium ions adsorbed to the

clay surfaces. Soil aggregates that slake and disperse indicate an unstable soil structure, which is not

favourable for infiltration by water (leading to run-off and erosion), or for root exploration (Needham et

al., 1998), and can be easily degraded. These soils should be seen as potentially problematic when

used for the reconstruction of soil profiles for rehabilitation, particular if left exposed at the surface.

The Emerson Aggregate Test identifies the potential slaking and dispersive properties of soil

aggregates. The dispersion test identifies the properties of the soil materials under a worst case

scenario, where severe stress is applied to the soil material. Generally, samples allocated into

Emerson classes 1 and 2 are those most likely to exhibit dispersive properties and therefore be the

most problematic.

Many of the soils from the Lake Maitland study area were identified as slaking and non-dispersive

(Table 34). While slaking reduces the infiltration capacity of soil, the lack of dispersion indicates that

the soils are unlikely to be hard-setting. One sample did not slake at all (Site 10, 0 – 5 cm), indicating


50

that the soil had good structurally stability. The remainder demonstrated dispersive properties initially

(Site 13, 0 – 5 cm), and upon re-moulding (Site 2, 10 – 20 cm; Site 3 0 – 5 cm; Site 5 (0 – 5 cm); Site

7 (0 – 5 cm); and Site15 (0 – 5 cm). Several soils remained dispersed in a 1:5 soil:water suspension

(Plate 30). These soil materials have the potential to become dispersive and problematic (hardsetting

/ erodible), particularly following severe disturbance. Care should be taken to minimise the handling of

soil materials where possible, particularly when wet.

The high salinity of the lake playa soils may have a flocculating effect on potentially dispersive

behaviour. These soils may become dispersive if there was substantial leaching of salt from the soil

matrix.

Table 34 Summary of slaking/dispersion properties (Emerson Test) results, indicating structural stability. Emerson Test classes are included in Appendix B

Site Depth (cm) Emerson class

(24 hour) Description

10 - 20 6 Slaked, no dispersion 1

40 - 50 6 Slaked, no dispersion

0 - 5 5 Slaked, minor dispersion 2

10 - 20 3a Slaked, remoulded soil dispersed

3 0 - 5 3b Slaked, remoulded soil dispersed

4 0 - 5 5 Slaked, minor dispersion


0 - 5 5 Slaked, minor dispersion 6

10 - 20 5 Slaked, minor dispersion






10 0 - 5 8 No slaking or dispersion

12 10 - 20 6 Slaked, no dispersion

13 0 - 5 2 Slaked, partially dispersed

14 10 - 20 4 Slaked, no dispersion, gypsum present



51

Plate 30 Examples of dispersed (b and c (minor)) and flocculated (a,d,e,f) 1 : 5 soil : water suspensions.

3.3.5 Soil Strength

3.3.5.1 Modulus of Rupture

A modified Modulus of Rupture (MOR) test was conducted on all samples collected. This test is a

measure of soil strength and identifies the tendency of a soil to hard-set as a direct result of soil

slaking and dispersion. A modulus of rupture of over 60 kPa has been described as the critical value

for distinguishing potentially problematic soils in agricultural scenarios (Cochrane and Aylmore 1997).

Restricted root penetration into the soil matrix is a likely consequence of a high modulus of rupture. In

reconstructed soil profiles, materials normally deep within the profile that may have a high MOR can

often be re-deposited closer to the surface, leading to germination / emergence and root penetration

problems.

Several of the soil materials measured from the Lake Maitland study site exhibited a capacity for hard

setting (Figure 11). Of the calcrete soils that were sampled, only Site 11 (40 – 50 cm) had a MOR

value high enough to be considered potentially problematic in regards to hard-setting behaviour. For

the lake playa soils, approximately half of the soil materials sampled exhibited potentially problematic

hard-setting behaviour. The soils sampled from the spinifex / acacia and spinifex associations

generally recorded MOR values below the potentially problematic hard-setting value of 60 kPa. The

MOR values recorded generally increased with depth in most profiles.

(b) (c) (d) (f) (e) (a)


52

As this test is conducted on reconstructed soil blocks composed of the < 2 mm soil fraction, it does not

take into account the effect of gravel content or soil structure on soil strength, nor any degree of

compaction that may be present in the field. It does, however, provide insight into the relative

potential for layers to hard-set and compact with repeated wetting and drying cycles, and the ability of

roots to fracture the soil and penetrate crack faces.

Figure 11 Individual and average modulus of rupture (kPa) values grouped into spinifex/acacia, spinifex, lake playa and calcrete sites (Error bars represent standard error). Red line indicates potential restrictions to plant and root development (Cochrane and Aylmore 1997)

3.3.5.2 Soil Penetration Resistance

The penetration resistance of a soil is a measure of the force required to break the soil’s cohesive and

frictional forces. This can be related to the ability of plant roots to penetrate the soil matrix. A soil with

a penetrometer resistance of >2 MPa is considered to be potentially problematic for cereal crop

production (Hunt and Gilkes, 1992), however an equivalent value for the native plant species within

the study area is not known.

The surface soils at the majority of sites within the study exhibited relatively low penetration

resistance, with the highest values being recorded within the spinifex and spinifex / acacia complex

soils, most noticeably at Sites 2, 4 and 7.

0

20

40

60

80

100

0 20 40 60 80 100 120

MOR (kPa)

Dep

th (c

m)


0

20

40

60

80

100

0 20 40 60 80 100 120

Average MOR (kPa)


lake playa calcrete


53

Figure 12: Individual and average penetration resistance (MPa) values grouped into spinifex/acacia, spinifex, lake playa and calcrete sites (Error bars represent standard error).

3.3.6 Soil Water Retention

The water retention properties of the soils within the study area are an important factor in determining

the amount of water available for plant growth when soil materials are re-deposited and rehabilitated.

In low-nutrient environments, such as that of the study area, the amount of water available to plants is

often the most limiting factor to vegetation establishment and growth. The water retention or water

holding capacity of a soil is influenced by a number of factors, with the particle size (and pore space)

distribution, soil structure and organic matter content being the most influential.

The five soils chosen for water retention measurements were typical of the range in soil textures

identified across the study area. Accordingly, there was a wide range of water retention

characteristics measured (Figure 13), and, with the percentage of coarse material taken into account,

a wide range of plant available water (PAW) values (Table 35). The soils (including coarse fraction)

were measured to retain from 12.7 to 52% water content by volume at field capacity (upper storage

limit). The volumetric water content at the maximum dryness likely to be achieved by plants (lower

storage limit) ranged from 2 to 19.9%. The actual level of soil water extraction able to be achieved

differs between species, but an indicative level of pF 5.6 (39000 kPa) was used for these estimates.

By comparison, pF 4.18 (1500 kPa) is typically used for agricultural species. The difference between

the upper and lower storage limits is the amount of water likely to be available to plants, and it ranged

from 10.2 to 34.7%.

0

20

40

60

80

100

0 5 10 15

Penetration resistance (MPa)

Dep

th (c

m)


0

20

40

60

80

100

0 5 10 15

Average penetration resistance (MPa)


lake playa calcrete


54

The major factors influencing the wide range of water retention characteristics identified include the

high coarse fraction (>2mm) of the Site 1, 90-100cm soil, and the high silt-sized fraction of the soils

from Sites 8 and 9 (sample sites on the lake playa).

Figure 13 Soil water retention curves for <2mm fraction of selected soil samples

Table 35 Range of plant available water (PAW) (%) for selected samples, corrected for % coarse material (>2mm)

Volumetric Water Content (%) Soil sample Upper storage limit

(field capacity)1 Lower storage limit

(wilting point)2

Plant Available Water (PAW) (%)3

Site 1, 90-100cm 12.7 2.5 10.2

Site 3, 40-50cm 27.2 3.2 24.0

Site 5, 40-50cm 27.0 3.0 24.0

Site 8, 40-50cm 48.3 19.9 28.4

Site 9, 90-100cm 52.0 17.3 34.7 1. based on pF 2 extraction

2. based on pF 5.6 extraction (estimate of level of water extraction by native plants)

3.difference between upper and lower storage limits

0

10

20

30

40

50

60

70

0 1 2 3 4 5 6pF

Vol

umet

ric W

ater

Con

tent

(%)

Site 1, 90-100cm Site 3, 40-50cm Site 5, 40-50cmSite 8, 40-50cm Site 9, 90-100cm


55

3.3.7 Root growth Root abundance was generally sparse within the majority of surface soil profiles, and obviously

dependant on proximity to plants and the number of plants present. Where roots were observed, root

abundance generally decreased rapidly with depth. Physical restrictions, such as compacted or

massive soil structures, and high gravel / rock contents, were common in many of the soil profiles,

however roots penetrated below the depth of excavation in most cases. The full extent of root

penetration into the underlying soil / regolith profile, beyond the depth of the soil pits, is unknown.


56

4.0 CONCLUSIONS AND RECOMMENDATIONS

From the investigation into soil profile characteristics within the survey area, it is apparent that a

significant degree of variation in soil profile morphology exists, both within and between the areas

sampled. The greatest variations in surface soil profile morphology exist between soils from

contrasting positions within the landscape, namely the spinifex, spinifex / acacia, lake playa and

calcrete associations.

The soils sampled exhibited a wide range of pH values with some consistency between soil pH and

position within the landscape or vegetation community. The soils from within the lake playa and

calcrete areas were generally more alkaline than those from within the spinifex and spinifex / acacia

vegetation associations, with both areas exhibiting a wide range of soil pH values. There was also a

wide range in salinity values across the study area. As expected the samples from the lake playa

recorded the highest salinity levels.

Soil nutrient analyses indicated generally low levels of available nutrients (N, P, K and S) that are

typical for the region. Levels of most nutrients tested were marginally higher in the lake playa soils

compared to samples from the other areas.

Measurements of total metal concentration of surface samples indicated that only very low levels of

As, Cd, Cr, Cu, Pb, Ni, Zn and Hg were present. Many materials sampled were below the detectable

limit for As, Cd, Pb, Zn and Hg, with only Cr, Cu and Ni regularly detected at a reportable level. For

the metals detected, there was no apparent correlation with landform / vegetation association.

There was significant variation in most of the physical soil attributes measured. Soil textures ranged

from loamy sand to light medium clay, with, in general, finer-textured soils present within the lake

playa. Soil structure was also variable, with little trend attributable to position within the landscape or

vegetation association.

Many soils sampled exhibited dispersive properties, or the tendency to disperse following severe

disturbance. This indicates that these materials may be potentially problematic once disturbed and re-

deposited. Measurements of soil strength upon drying indicated that the majority of the soils assessed

did not hardset.

The water retention characteristics of the soils measured were variable, reflecting the variability in soil

texture and amount of coarse material (>2 mm) across the study area.


57

4.1 Soil stripping and management for rehabilitation

Rehabilitation of potential waste landforms and other areas of disturbance associated with the project

should be broadly based on the natural soil-landform-vegetation associations that exist within the

project area.

It is likely that the separate collection and stockpiling of topsoil and overburden materials from within

the identified areas would enhance the rehabilitation potential by preserving the seed store, and the

chemical, physical and biological attributes of the soils on which the individual vegetation communities

are located. While differences in soil properties and profile characteristics between areas complicate

the requirements for material handling, soil stripping and handling guidelines must be broad enough to

fit into logistical operations of earthworks and mining activities.

As a general guide it is recommended that the top 0.15 m of soil be stripped and stockpiled as topsoil.

Topsoil stockpiles should be kept as low as practicable (ideally < 2 m) through a ‘paddock dumping’

approach to encourage biological activity and plant establishment. Topsoil stockpiles should be re-

seeded as soon as possible.

Separate collection and stockpiling of the gypsiferous soils (Kopi area) on the eastern perimeter of the

lake playa may be pertinent for future use as an ameliorant for potentially dispersive soils during

rehabilitation operations.

4.2 Further work

Issues requiring consideration during project development include topsoil and subsoil / overburden

management, the poor structural stability (slaking and dispersion) of some ‘surface’ soils, and the

physical / chemical characteristics of deeper regolith materials expoased during mining activities.


58

5.0 REFERENCES Allen, D.G. and Jeffrey, R.C. (1990). Report of the Investigation No. 37 ‘Methods for Analysis of

Phosphorus in Western Australian Soils’.

Aylmore, L.A.G. and Sills, I.D. (1982). Characterisation of soil structure and stability using modulus of

rupture – ESP relationships. Australian Journal of Soil Research 62: 213-224.

Blair, G.J., Chinoim, N., Lefroy, R.D.B., Anderson, G.C. and Crocker, G.J. (1991). A soil sulphur test

for pastures and crops. Australian Journal of Soil Research 29: 619-626.

Cochrane, H.R. and Aylmore, L.A.G. (1997). Modulus of rupture. Section 9.2 In: Soil physical

measurement and interpretation for land evaluation. Australian Soil and Land Survey Handbook

Series, Vol. 5.

Colwell, J.D. (1965). An automated procedure for the determination of phosphorus in sodium

hydrogen carbonate extracts of soils. Chemistry and Industry, May, 893-895.

Cowan (2001). Murchison 1 (MUR1 – East Murchison subregion) In May, J. & McKenzie, N. (Eds) A

Biodiversity Audit of Western Australia’s 53 Biogeographical Subregions in 2002. Department of

CALM (CALM, now DEC) pp 466 – 479.

URL: www.naturbase.net/pdf/science/bio_audit/murchison01_p466-479.pdf

(Accessed: February 13th, 2007)

Harper, R.J., and Gilkes, R.J. (1994). Hardsetting in the surface horizons of sandy soils and its

implications for soil classification and management. Australian Journal of Soil Research 32: 603-619.

Hunt, N., and Gilkes, R. (1992). Farm monitoring handbook, a practical down-to-earth manual for

farmers and other land users. The University of Western Australia, Nedlands.

McDonald, R.C., Isbell, R.F., Speight, J.G., Walker, J. and Hopkins, M.S. (1998). Australian Soil and

Land Survey – Field Handbook. Australian Collaborative Land Evaluation Program, CSIRO Land and

Water, Canberra.

McKenzie, N., Coughlan, K., and Cresswell, H. (2002). Soil physical measurement and interpretation

for land evaluation. CSIRO Publishing.

Moore, G. (1998). Soilguide. A handbook for understanding and managing agricultural soils.

Agriculture Western Australia. Bulletin No. 4343.

http://www.naturbase.net/pdf/science/bio_audit/murchison01_p466-479.pdf


59

Needham, P., Moore, G., and Scholz, H. (1998). Soil Structure Decline. In: Soil Guide. A Handbook

for Understanding and Managing Agricultural Soils. (Ed. Moore, G). Agriculture Western Australia

Bulletin No. 4343, pp 64-79.

OES (2007). Vegetation and Flora Baseline Survey. Interim Report. Unpublished report prepared for

Mega Redport Pty Ltd. Outback Ecology Services

Pringle, H.J.R, Van Vreeswyk, A.M.E. and Gilligan, S.A. (1994). An inventory and condition survey of

the north-eastern Goldfields, Western Australia. Department of Agriculture Western Australia

Technical Bulletin 87

Rayment, G.E., and Higginson, F.R. (1992). Australian Laboratory Handbook of Soil and Chemical

Methods. Inkata Press, Melbourne. pp. 68.

Scarle, P.L. (1984). Analyst 109: 549-568.

Walkley, A. and Black, I.A. (1934). An examination of the Degtjareff method for determining soil

organic matter, and a proposed modification of the chromic and titration method. Soil Science 37: 29-

38.

60

Appendix A Glossary of terms

61

Glossary of terms Aggregate (or ped) A cluster of primary particles separated from adjoining peds by

natural planes of weakness, voids (cracks) or cutans.

Bulk density Mass per unit volume of undisturbed soil, dried to a constant

weight at 105°C.

Clay The fraction of mineral soil finer than 0.002mm (2µm).

Coarse fragments Particles greater than 2mm in size.

Consistence The strength of cohesion and adhesion in soil.

Dispersion The process whereby the structure or aggregation of the soil is

destroyed, breaking down into primary particles.

Electrical conductivity How well a soil conducts an electrical charge, related closely to

the salinity of a soil.

Massive soil structure Coherent soil, no soil structure, separates into fragments when

displaced. Large force often required to break soil matrix.

Modulus of Rupture (MOR) This test is a measure of soil strength and identifies the tendency

of a soil to hard-set as a direct result of soil slaking and

dispersion.

Organic Carbon Carbon residue retained by the soil in humus form. Can influence

many physical, chemical and biological soil properties.

Synonymous with organic matter (OM).

pF Measure of extraction level of the soil water characteristic.

pF = log10(-cm H2O at 20cm).

Plant available water The ability of a soil to hold that part of the water that can be

absorbed by plant roots. Available water is the difference between

field capacity and permanent wilting point.

Regolith The unconsolidated rock and weathered material above bedrock,

including weathered sediments, saprolites, organic accumulations,

soil, colluvium, alluvium and aeolian deposits.

62

Single grain structure Loose, incoherent mass of individual particles. Soil separates into

individual particles when displaced.

Slaking The partial breakdown of soil aggregates in water due to the

swelling of clay and the expulsion of air from pore spaces.

Soil horizon Relatively uniform materials that extend laterally, continuously or

discontinuously throughout the profile, running approximately

parallel to the surface of the ground and differs from the related

horizons in chemical, physical or biological properties.

Soil pH The negative logarithm of the hydrogen ion concentration of a soil

solution. The degree of acidity or alkalinity of a soil expressed in

terms of the pH scale, from 2 to 10.

Soil structure The distinctness, size, shape and arrangement of soil aggregates

(or peds) and voids within a soil profile. Can be classed as

‘apedal’, having no observable peds, or ‘pedal’, having observable

peds.

Soil strength The resistance of a soil to breaking or deformation. ‘Hardsetting’

refers to a high soil strength upon drying.

Soil texture The size distribution of individual particles of a soil.

Subsoil The layer of soil below the topsoil or A horizons, often of finer

texture (i.e. more clayey), denser and stronger in colour.

Generally considered to be the ‘B-horizon’ above partially

weathered or un-weathered material.

Topsoil Soil consisting of various mixtures of sand, silt, clay and organic

matter; considered to be the nutrient-rich top layer of soil – The ‘A-

horizon’.

63

Appendix B Summary of methods of soil analyses used by Outback Ecology

64

1. Soil texture

Soils were worked by hand, and the texture, shearing capacity, particle size and ribbon length were

observed according to methods described in McDonald et al. (1998) as follows.

Texture Grade Behaviour of Moist Bolus Approximate

clay content Code

Sand Nil to very slight coherence; cannot be moulded; single sand grains adhere to fingers <5% S

Loamy sand Slight coherence; can be sheared between thumb and forefinger to give minimal ribbon of about 5mm

5% LS

Clayey sand Slight coherence; sticky when wet; many sand grains stick to fingers; discolours fingers with stain; forms minimal ribbon of 5-15mm

5-10% CS

Sandy loam Bolus coherent but very sandy to touch; dominant sand grains of medium size and readily visible ; ribbon of 15-25mm

10-20% SL

Loam Bolus coherent and rather spongy; no obvious sandiness or silkiness; forms ribbon of about 25mm

25% L

Sandy clay loam

Strongly coherent bolus; sandy to touch; ribbon of 25-40mm 20-30% SCL

Clay loam Coherent plastic bolus, smooth to touch, ribbon of 25mm to 40mm 30-35% CL

Clay loam, sandy

Coherent plastic bolus, sand grains visible in finer matrix, ribbon of 40-50mm; sandy to touch 30-35% CLS

Light clay Plastic bolus, smooth to touch; slight resistance to shearing; ribbon of 50-75mm 35-40% LC

Light medium clay

Ribbon of about 75mm, slight to moderate resistance to ribboning shear 40-45% LMC

Medium clay

Smooth plastic bolus, handles like plasticine and can be moulded into rods without fracture; moderate resistance to ribboning shear, ribbon of 75mm or longer

45-55% MC

Medium heavy clay

Ribbon of 75mm or longer, handles like plasticine, moderate to firm resistance to ribboning shear

>50% MHC

Heavy Clay Handles like stiff plasticine; firm resistance to ribboning shear, ribbon of 75mm or longer >50% HC

65

2. Emerson Dispersion Test

Emerson dispersion tests were carried out on all samples according to the following procedure:

1. A petri dish was labelled 1 to 6. eg.

2. The petri dish was filled with DI water. 3. A 3-5mm soil aggregate is taken from each sample and gently placed into the labelled petri dish

(3 per dish).

4. Additional aggregates, remoulded by hand, are placed into the labelled petri dish (3 per dish).

5. Observations are made of the dispersivity or slaking nature of the sample according to the

following table:

Emerson Aggregate test classes (Moore 1998)

The samples were left in the dish for a 24 hour period, after which the samples were observed

again and rated according to the above Table.

Class Description

Class 1 Dry aggregate slakes and completely disperses

Class 2 Dry aggregate slakes and partly disperses

Class 3a Dry aggregate slakes but does not disperse; remoulded soil disperses completely

Class 3b Dry aggregate slakes but does not disperse; remoulded soil partly disperses

Class 4 Dry aggregate slakes but does not disperse; remoulded soil does not disperse;

carbonates and gypsum are present


carbonates and gypsum are absent; 1:5 suspension remains dispersed


carbonates and gypsum are absent; 1:5 suspension remains flocculated

Class 7 Dry aggregate does not slake; aggregate swells

Class 8 Dry aggregate does not slake; aggregate does not swell

1 2

3 4

5 6

66

Appendix C Summary of Outback Ecology soil analysis results

67

Summary of Outback Ecology results for field texture, gravel content, soil strength (modulus of rupture) and slaking/dispersion (Emerson Test).

Site Depth (cm) Complex Field Texture Gravel

Content (%) MOR (kPa) Emerson

0-5 Sandy loam 6.4 9.2 - 10-20 Sandy clay loam 8.8 11.5 6 40-50 Sandy clay loam 48.5 16.2 6

1

90-100

spinifex acacia

Sandy loam 67.2 4.9 - 0-5 Clay loam sandy 3.4 36.0 5

10-20 Clay loam sandy 22.8 14.3 3a 40-50 Sandy clay loam 47.1 3.9 -

2

90-100

spinifex acacia

Loamy sand 60.4 0.6 - 0-5 Sandy loam 1.9 8.5 3b

10-20 Clayey sand 2.2 4.4 - 40-50 Sandy loam 3.0 3.4 -

3

90-100

spinifex acacia

Sandy loam 6.3 6.5 - 0-5 Clayey sand 3.3 7.8 5

10-20 Sandy clay loam 6.2 9.5 - 40-50 Clay loam sandy 10.1 8.9 -

4

90-100

spinifex

Light medium clay 6.4 31.5 - 0-5 Clayey sand 2.4 7.2 3b

10-20 Sandy loam 2.9 13.8 - 40-50 Sandy loam 7.3 6.7 -

5

90-100

spinifex

Sandy clay loam 50.7 16.3 - 0-5 Sandy clay loam 1.9 5.9 5

10-20 Sandy clay loam 2.7 3.6 5 40-50 Sandy loam 3.1 6.0 -

6

90-100

spinifex acacia

Clay loam sandy 7.3 11.1 - 0-5 Clayey sand 4.6 5.6 3b

10-20 Sandy clay loam 11.1 4.6 - 40-50 Clay loam sandy 11.2 1.8 -

7

90-100

spinifex

Clayey sand 41.4 1.9 - 0-5 Sandy loam 0.0 4.6 6

10-20 Sandy clay loam 0.0 16.2 6 40-50 Light clay 1.8 71.4 -

8

90-100

lake playa

Clay loam sandy 15.0 60.0 - 0-5 Clayey sand 0.5 19.2 -

10-20 Loam 0.8 59.0 6 40-50 Loam 0.0 64.7 6

9

90-100

lake playa

Light medium clay 0.0 94.3 - 0-5 Sandy loam 14.3 9.8 8 10

10-20 calcrete

Light clay 17.9 21.0 - 0-5 Sandy loam 14.3 15.8 -

10-20 Sandy loam 41.8 7.8 - 11 40-50

calcrete Sandy clay loam 36.2 78.6 -

0-5 Clayey sand 0.7 7.3 - 10-20 Clay loam 0.0 106.8 6 12 40-50

lake playa Light clay 0.0 28.8 -

0-5 Clay loam 14.3 26.2 2 13

10-20 calcrete

Clay loam sandy 24.6 10.9 - 0-5 Sandy loam 7.7 18.6 -

14 10-20

spinifex acacia Clay loam 6.7 7.6 4

0-5 Sandy loam 13.6 9.2 3b 15

10-20 lake playa

Sandy clay loam 56.0 18.6 -

68

Appendix D Summary of CSBP analyses

69

Summary of CSBP analyses

ANALYSIS REPORT

CSBP LIMITED ABN: 81 008 668 371

mg/kg mg/kg mg/kg mg/kg mg/kg mg/kg dS/m % pH pH

Site

Dep

th (c

m)

TEXT

UR

E

GR

AVE

L

CO

LOU

R

NIT

RA

TE N

AM

MO

NIU

M

PHO

SPH

OR

US

POTA

SSIU

M

SULP

HU

R

IRO

N

CO

ND

UC

TIVI

TY

OR

G C

AR

BO

N

PH C

aCl2

PH H

2O

Site 1 0-5 3 5-10 BROR 2 1 5 253 7.7 281 0.09 0.63 7.9 8.9 Site 1 10-20 2.5 5-10 BROR 2 1 3 327 16 215 0.248 0.61 8.4 9.3 Site 1 40-50 3 LTBR 6 1 2 413 757 208 3.826 0.64 8.2 8.6 Site 1 90-100 2.5 LTBR 10 1 2 346 471 138 3.225 0.39 8.4 8.8 Site 2 0-5 3 BROR 17 4 7 181 16.1 574 1.363 0.53 7.6 8 Site 2 10-20 3 BROR 3 1 2 499 208 500 0.762 0.26 7.6 8.2 Site 2 40-50 3 15-20 BROR 3 1 2 779 1417 409 2.291 0.22 7.8 7.8 Site 2 90-100 3 25-30 BROR 3 1 2 716 2442 347 2.62 0.19 7.9 8.2 Site 3 0-5 1.5 BROR 2 2 2 93 8.4 593 0.02 0.54 4.5 5.5 Site 3 10-20 1.5 BROR 3 1 2 113 24.4 680 0.03 0.25 4.4 5.4 Site 3 40-50 1.5 BROR 3 1 2 87 13.9 629 0.023 0.23 4.6 5.7 Site 3 90-100 1.5 BROR 3 1 2 129 10.1 671 0.127 0.21 5.7 5.9 Site 4 0-5 1.5 BROR 3 1 2 68 3.7 534 0.019 0.33 5.1 6.1 Site 4 10-20 1.5 BRRD 3 1 2 98 8.1 576 0.021 0.32 5.3 6.2 Site 4 40-50 1.5 BRRD 3 1 2 104 3.8 566 0.012 0.26 5.6 6.5 Site 4 90-100 1.5 BRRD 3 1 2 164 9.9 620 0.032 0.24 6.4 7.2 Site 5 0-5 1.5 5-10 BRRD 3 1 2 104 55.3 543 0.063 0.28 6 6.7 Site 5 10-20 1.5 BRRD 3 1 2 116 15.8 554 0.03 0.27 5.8 6.7 Site 5 40-50 1.5 BRRD 2 1 2 114 8.4 528 0.011 0.22 5.3 6.4 Site 5 90-100 3 BROR 3 1 2 118 14 589 0.024 0.22 5.6 6.4 Site 6 0-5 3 BROR 3 3 6 151 5.9 507 0.026 0.43 4.3 5.3 Site 6 10-20 3 5-10 BROR 3 1 2 124 19.9 549 0.042 0.31 4.2 4.9 Site 6 40-50 2.5 5-10 BROR 3 1 2 159 9.5 529 0.017 0.22 4.7 5.7 Site 6 90-100 2.5 5-10 BROR 3 1 2 159 55.2 448 0.125 0.24 5.6 6.1

70

mg/kg mg/kg mg/kg mg/kg mg/kg mg/kg dS/m % pH pH

Site

Dep

th (c

m)

TEXT

UR

E

GR

AVE

L

CO

LOU

R

NIT

RA

TE N

AM

MO

NIU

M

PHO

SPH

OR

US

POTA

SSIU

M

SULP

HU

R

IRO

N

CO

ND

UC

TIVI

TY

OR

G C

AR

BO

N

PH C

aCl2

PH H

2O

Site 7 0-5 2.5 5-10 BROR 3 1 2 73 34.1 521 0.076 0.25 4.5 5.3 Site 7 10-20 2.5 5-10 BROR 3 1 2 96 210 512 0.346 0.27 5.8 6.1 Site 7 40-50 2.5 5-10 BROR 3 1 2 128 50.5 472 0.192 0.24 5.8 6.3 Site 7 90-100 2.5 5-10 BROR 15 1 2 179 1362 237 1.42 0.17 7 7.8 Site 8 0-5 1.5 15-20 LTBR 9 1 36 243 4194 683 4.088 0.53 8.1 8.2 Site 8 10-20 1.5 BROR 24 1 7 520 5950 418 8.1 0.56 8 8.1 Site 8 40-50 2.5 LTBR 30 1 3 930 7245 377 9.999 0.55 8.1 8.2 Site 8 90-100 2.5 BR 46 1 2 1169 7901 292 9.999 0.55 8.1 8.2 Site 9 0-5 2 LTBR 3 1 13 231 5224 381 4.14 0.53 8.3 8.4 Site 9 10-20 2 LTBR 6 1 9 206 5726 175 4.049 0.28 8 8.2 Site 9 40-50 1.5 LTBR 16 1 5 382 7360 192 6.263 0.33 8.1 8.3 Site 9 90-100 2.5 LTBR 38 1 3 966 7050 385 9.999 0.44 8.1 8.2 Site 10 0-5 2 LTBR 3 1 2 222 1158 266 0.659 0.65 8.3 8.6 Site 10 10-20 2 LTBR 2 1 3 373 286 224 0.762 0.64 8.1 8.4 Site 11 0-5 2 5-10 LTBR 2 1 2 196 28.8 223 0.135 0.69 8.1 8.9 Site 11 10-20 2 5-10 LTBR 6 1 6 221 5629 182 2.095 0.71 7.9 8.1 Site 11 40-50 2 5-10 LTBR 10 1 2 342 143 124 2.325 0.61 8.2 8.6 Site 12 0-5 1.5 LTBR 2 1 9 108 6128 203 2.608 0.41 8.2 8.4 Site 12 10-20 2.5 BR 7 1 3 337 6599 377 3.95 0.38 8.1 8.3 Site 12 40-50 2.5 BR 12 1 2 562 6832 282 6.596 0.38 8.1 8.2 Site 13 0-5 3 LTBR 3 1 6 400 773 279 0.485 0.65 8.2 8.9 Site 13 10-20 3 LTBR 3 1 2 590 321 231 0.344 0.68 8.4 9.2 Site 14 0-5 2 BRWH 3 1 8 36 5787 24 1.998 0.41 8 8.5 Site 14 10-20 2.5 BRWH 3 1 4 72 6174 0 2.315 0.41 8 8.3 Site 15 0-5 2 15-20 BR 3 1 4 111 912 171 0.975 0.56 8 8.7 Site 15 10-20 2 55-60 BR 3 1 4 148 128 213 0.159 0.75 8 8.8

71

Appendix E Soil Electrical Conductivity (EC) classes

72

Soil Electrical Conductivity classes (based on standard USDA and CSIRO categories)

EC (1:5) (dS/m)

Salinity Class Sand Sandy loam

Loam Clay loam

Light/Med Clay

Heavy Clay

Non-saline <0.13 <0.17 <0.20 <0.22 <0.25 <0.33

Slightly Saline 0.13-0.26 0.17-0.33 0.20-0.40 0.22-0.44 0.25-0.50 0.33-0.67

Moderately Saline 0.26-0.52 0.33-0.67 0.40-0.80 0.44-0.89 0.50-1.00 0.67-1.33

Very Saline 0.52-1.06 0.67-1.33 0.80-1.60 0.89-1.78 1.00-2.00 1.33-2.67

Extremely Saline >1.06 >1.33 >1.60 >1.78 >2.00 >2.67

73

Appendix F Root scoring categories

74

Scoring of root abundance

Root abundance is scored on a visual basis within the categories defined by McDonald et al.., 1998:

Roots per 10 cm2 Score

Very fine and fine roots Medium and coarse roots

0 – No roots 0 0

1 – Few 1 - 10 1 or 2

2 – Common 10 - 25 2 – 5

3 – Many 25 - 200 >5

4 - Abundant >200 >5

75

Appendix G

Slaking / dispersion examples

76

Outback Ecology laboratory results; dispersion / slaking photos

Plate AG1 Slaked soil prior to re-moulding (left), completely slaked and dispersed after re-moulding (right) (Site 2, 10-20)

Plate AG3 Slaked soil prior to re-moulding (left) fully slaked and partially dispersed after re-moulding (right) (Site 3, 0-5)

Plate AG2 Non-dispersive soil, completely slaked both prior and after re-moulding (Site 4, 0-5)

Plate AG4 Non- slaking or dispersive soil (left), slaked after re-moulding (Site 10, 0-5)

Documents

Mega Redport Pty Ltd...Mega Redport Pty Ltd Lake Maitland Baseline Soil Survey September 2007 Outback Ecology Services 1/71 Troy Terrace Jolimont WA 6014 Ph: +61 (08) 9388 8799 Fax: