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Soil Constraints – West: a GRDC initiative to
develop soil management systems for the
future
Bob Belford, John Even, Tony White
February 2015
Aims:
• To develop an ‘Initiative’ between four GRDC Western Region soil constraints
projects
- Non wetting soils ($7.5M over five years; Steve Davies)
- Soil compaction ($1.4M; Paul Blackwell)
- Sub-soil constraints ($4.4M; David Hall)
- Soil acidity ($1.6M; Chris Gazey)
• Develop links to, and awareness of other soils projects (e.g. MCPN, nutrition,
biology, carbon) in WA and nationally which also contribute to sustainable soil
management systems
• Form a Steering committee of RCSN representatives, project leaders, GRDC
(Western Panel and Canberra) to provide guidance and feedback to projects and
GRDC
Background:
• Rising yield potential and understanding of WUE focuses on soil constraints
as limiting factors to crop production
• Constraints cost WA growers money in lost production; 2009 estimates are
$250M (non-wetting); $498M (acidity); $600M subsoil constraints; and
$333M (compaction) per year
• Substantial investments in soils by GRDC over many years, but often as single
issue, short term projects looking at individual problems
• Many problems don’t exist in isolation, and a ‘holistic’ approach is needed to
tackle soil constraints at farm and paddock scale
• Consistent with GRDC’s aim to link projects to create ‘Initiatives’ and add
value to the investments: e.g. Precision Agriculture, Sub-soil constraints, Soil
Biology, Grain and Graze, MPCN, Crown Rot, and the National Frost
Initiative
Why have an initiative?
a) Will allow interactions between individual constraints to be
identified and quantified, and management systems defined.
Non-wettingsoils
AciditySubsoilconstraints
Managingcompaction
b) ‘Soil constraints’ highly ranked within GRDC themes and
across RCSN regions:
Alb Esp Ger Kw West Kw East
Non -wetting Yes Yes Yes - Yes
pH Yes (Yes) Yes Yes -
Compaction Yes Yes Yes - Yes
Sub-soil
constraints*
(Yes) (Yes) - Yes Yes
* Identified as limitations to water supply
Why have an initiative?
Source: RCSN annual report 2012/3
Report card on sustainable natural resource use in agriculture
https://www.agric.wa.gov.au/climate-land-water/resource-assessment/report-card-conditions-and-trends
Why have an initiative?
c) A partner in GRDC’s National Soil Constraints initiative
“Growers are increasingly aware of the impacts of soil constraints from comparison of
actual yield with water-limited potential yield (or target yield). Identifying the most
effective way to manage these constraints is a high priority topic for many grain-
growing regions.
The cost-price squeeze faced by growers and the need to match expensive inputs to
potential yield, as well as increasing variability and risk due to climate, emphasises the
importance of this issue”.
Source: GRDC Investment Plan 2015-6
* Linked to projects/staff in
Soil Constraints - West
*
* * *
GRDC’s National
Soil Constraints
Initiative
*
Why have an initiative?
d) 2015 is the FAO International Year of Soils
(IYS) – “Healthy soils for a healthy life”
• to create awareness about the fundamental roles of soils for human life;
• to recognise the contributions of soils to food security and nutrition, climate
change adaptation and mitigation, essential ecosystem services, poverty
alleviation and sustainable development;
• to promote policies and actions for the sustainable management and protection
of soil resources;
• to sensitize decision-makers about the need for investment in sustainable soil
management activities, to ensure healthy soils for different land users and
population groups;
• to enhance capacities and systems for soil information collection and
monitoring at all levels (global, regional and national).
http://www.fao.org/soils-portal/en/
https://www.agric.wa.gov.au/mysoil
Non-cracking clays
Deep sands
Gravels Sandy duplex
Alkaline shallow
duplex
Clays and shallow
loamy duplex
Soils in WA
Project 1. Delivering enhanced agronomic strategies for
improved crop performance on water repellent soils (Steve
Davies, DAFWA, with CSIRO and UM)
Nearly 3.3M hectares of Western Australia's agricultural soils are at high risk of soil
water repellence with a further 6.9M hectares at moderate risk. Soil water repellence
results in poor, patchy and delayed crop and pasture emergence.
The key aims are:
• To increase knowledge of soil water repellence in WA cropping systems and
develop strategies to manage soil water repellence.
• An extension strategy for growers, consultants and agronomists to select the best
management options for water repellent soils on WA farms.
• Build and retain soils research capacity in the West through appointment and
training of PhD students, a post-doctoral fellow and regionally based graduates.
Project 2. Soil Acidity is limiting grain yield - coordinating the
improved management of soil acidity in Western Australia and
the Southern Region (Chris Gazey and Liam Ryan, DAFWA)
• Acidity is severe and widespread, and a major risk to production; it is estimated that soil
acidity costs WA growers $498 million per year in lost productivity.
• Factors contributing to soil acidification are understood, as are the best practice management
systems. The disconnect is limited adoption of soil testing to depth to determine pH and
develop appropriate management plans, which must include application of lime where pH is
less than the recommended targets.
• This project aims to double agricultural lime use in WA from the 2010 base. A whole of
industry approach is required through an industry wide working group, with on-going
education, extension and training of key advisors/consultants to support growers into the
future.
Project 3. Subsoil constraints – understanding and management
(David Hall, DAFWA, with Yvette Oliver, CSIRO)
• Subsoil constraints (SSC) cost WA growers more than $600 M pa in lost production. Constraints include
subsoil acidity, nutrient deficiencies/toxicities, compaction, sodicity/waterlogging and
alkalinity/boron/transient salinity. These constraints reduce root depth and function; water and nutrient
levels are insufficient to sustain production near the rainfall limited yield potential.
• Diagnostics are often insufficient for growers to identify and manage constraints. This is important as
many farmers are experiencing reduced margins due to drying climates and increasing costs relative to
returns.
• This project will increase profitability through improved subsoil management. This may be through
amelioration but may also be mitigation where the constraints cannot be profitably rectified. Outputs will
result in improved yields, reduced costs and enhanced confidence by growers and their advisors in
managing SSC.
• This work builds on other GRDC projects including those in the Soil Constraints – West Initiative, plus
Focus paddocks (DAW00213), the Water-use Efficiency initiative (DAW00193), and Measuring and
managing soil water (CSP00170).
Project 4. Minimising the impact of soil compaction on crop
yield (Paul Blackwell and Doug Abrecht, DAFWA)
• Soil compaction is widespread, with the annual cost of compaction estimated as $333M. The project will
improve knowledge of profitable options to better manage subsoil compaction in WA.
• Subsoil compaction holds back crop growth by restricting root growth and increasing the risk of
waterlogging in the soil profile. This can reduce grain yield and increase costs.
• Previous R&D has provided management options for better control of compaction. These include deep
cultivation (20 – 30% grain yield increase), and controlled traffic systems (10% more grain yield).
• Declining terms of trade and poor seasons have led to an increase in size, capacity and loaded weight of
machinery. This increases the depth and severity of subsoil compaction, e.g. to 500mm rather than
300mm depth. Optimum management strategies now involve both traffic control and removal of deep
subsoil compaction.
• CTF may double farm profit, but many growers have found difficulty matching machinery and are reluctant
to compromise efficiencies. This project will evaluate the financial and environmental benefits of CTF, and
the transitions growers can adopt to capture the benefits.
Steering committee and management of the initiative:
• RCSN members – Craig Topham (Ger), Quentin Knight (Esp), Mark Pearce
(Alb), Bob Nixon (Kw East), Tony White (Kw West)
• Project leaders – Steve Davies, David Hall, Paul Blackwell, Chris Gazey
(DAFWA)
• GRDC – John Even (Western Panel), Martin Blumenthal (Canberra)
• Chair – Bob Belford
AND
• Collaborating project staff, other soils experts, GRDC representatives,
industry specialists (will vary with nature and location of meeting)
• Minimum of two formal meetings per year, with at least one to include a
field visit
Challenges facing the Steering committee……• ‘Integration’ and ‘value adding’ – often mentioned, but how?
Shared field sites, field days, presentations, outputs, planning activities and investment
strategy – and an independent Steering Committee
• Extension strategies:
- grower groups/learning groups and modules
- consultants and advisors
- approaches (GRDC’s ‘bakers dozen’)
- extension expertise within and outside projects
- case studies
- benchmarking
• Decision support tools – value to, and demand from industry?
• Economics – not usually the main focus of research projects; however, an essential component of projects
for end-users, and analysis at farm scale rather than gross margin analysis in a paddock
• Complexity – many interactions within and between projects in Soil Constraints – West, and with other
soils projects (WA and National)
In summary:
• A five year commitment by GRDC, $6.5M p.a.
• An evolving part of GRDC’s National approach to soil management, recognising
regional differences
• ‘Value adding’ by sharing sites, activities and information and actively planning
future investments
• Strong links to industry, including a Steering Committee to assess progress and
provide feedback
• Active participation of grower and industry groups to help set direction participate
in trials and research, and deliver outcomes
• Focussed, consistent and timely communication to all communicators, media and
stakeholders
A word from our sponsors………..
Three key messages:
• A $33M Western region investment over five years into major soil
constraints and their interactions – soil acidity, compaction, non-wetting
soils and subsoil constraints – to develop sustainable soil management
systems for the future.
• Input from GRDC and research agencies in WA (DAFWA, Murdoch Uni,
CSIRO), grower and industry groups, and linked to other soil investments
in WA, under the guidance of a Steering Committee.
• A component of a new GRDC National Soil Constraints Initiative starting
in 2015, to maximise returns to industry from research $$ invested.
