A building block of life and prosperity
Healthy soils are central to human health and wellbeing. They support the production of food and fibre we need to survive and support the ecosystems which enable clean water, pure air, biodiversity and environmental quality.
A teaspoon of soil is estimated to contain several thousand species of micro-organisms, and other invertebrates such as nematodes (round worms), annelids (earth worms), and microarthropods (springtails and mites). These soil organisms play very important roles such as breaking down organic matter and providing nutrients to plants.
Healthy soils are also vital to our region’s economic prosperity, helping to generate more than $1.66 billion worth of agricultural production to the region’s economy each year.
Our region’s soils are ancient and fragile. The plants, animals and microorganisms that have maintained them for millennia are stressed mainly through the introduction of European plants, animals and farming techniques. Today, there are many issues that affect our soils and landscapes including climate change, acidification, compaction, salinity, erosion, dumping of clean or contaminated soil, fertility decline, and decline of biodiversity.
Safeguarding the health of our soils is vital to our region’s future. The costs from degraded soils and their management can be very high and impact agricultural producers, commerce, industry and urban users, and the natural ecosystem.
Policy and planning
At the national level, the Australian Government has released a National Soil Strategy with goals to:
- Prioritise soil health
- Empower soil innovation and stewards
- Strengthen soil knowledge and capability.
At the state level, the Victorian Department of Environment, Land, Water and Planning has a key role in developing and implementing soil health policy. The Environment Protection Authority plays an important role in the protection of human health and the environment, including soils, from pollution and waste.
The Victorian Government has legislative requirements for reporting on change in soil condition under the Catchment and Land Protection Act (1994) by the Victorian Catchment Management Council and the Commissioner for Environmental Sustainability Act (2003) by the Commissioner for Environmental Sustainability. Both report every five years. This reporting is important to identify any important change in soil condition that might trigger government intervention.
The region’s soils now
The Port Phillip and Western Port region has a variety of surface-level soil types that reflect differences in parent material, topography, climate, organic activity and age, as indicated in the map below.
The health of soils
Factors that should be considered in assessing soil health include soil acidity (pH), phosphorous and nitrogen levels, soil salinity, soil compaction and microbial health. Soil carbon is also important, and becoming increasingly so due to the importance of sequestering and retaining carbon to help address climate change.
The health of soil, as measured by these parameters, is highly variable at local level due to the particular local conditions and the management history of the site.
The condition and trends of soil health using these parameters have not been systematically recorded and mapped at landscape level. Instead, a proxy for broad soil health and vulnerability assessment, for which data has been collected and mapped for some decades nationally through the Australian National University, is the percentage of exposed soil.
The graph below shows that, across the region over the past 20 years, the proportion of exposed soil has been steady at between 10% to 15%. This is a relatively low level and indicates that, in general, little of the soil across the region is at high risk of wind erosion.
Proportion of exposed soils for the region from 2000 to 2020 (with data from Australian National University)
Climate change has the potential to have a severe, but variable, impact on soils, depending on the climatic zone and the existing vulnerability of the soil. Droughts will require agricultural land to be irrigated and fertilized more to maintain productivity, while erosion caused through flash flooding can have significant implications for natural assets, agricultural lands and water quality. Sea level rise will increase salinity in coastal areas.
Soil acidification restricts options for land management because it limits the choice of crops and vegetation to acid-tolerant species and varieties. It is relatively straightforward to reverse short-term surface soil acidification through the application of lime. However, it is much harder to reverse the problem if the acidification has advanced deeper into the soil profile, because incorporating lime at depth is more expensive.
Soil structure decline: compaction and sodicity
Structure is an essential part of soil health and its ability to support plants and soil organisms. Air spaces between soil particles are essential to the movement and exchange of water, gases and plant roots.
Compaction occurs when the air spaces between soil particles are lost due to vehicle traffic, animal hoof impact and cultivation. Compaction restricts root penetration and micro-organism activity. Compaction is often made worse in wet soils. Surface compaction from animal hooves is relatively easy to remediate but the deeper impact of vehicle traffic is difficult to remediate. It leads to or exacerbates water logging and anaerobic soil conditions. Soils in many parts of the Port Phillip & Western Port region have now been damaged by compaction by vehicles, stock and cultivation for up to 150 years.
Sodicity damages soil structure and fertility. Sodicity degrades soil when sodium salts weaken the bond between soil particles. Sodic soils disperse in water and become vulnerable to erosion. Gully and tunnel erosion are common signs of sodic subsoils while crusting and sealing that impedes water infiltration is a feature of sodic surface-soils. Soil sodicity is considered a major problem in Alkaline Sodic Soils on agricultural land west of Melbourne. The Parwan Creek valley contains some examples.
Soil salinity occurs when salts accumulate in the soil profile to such an extent that plant growth is adversely affected.
The physical environment changes both in the immediate area (with degradation of wildlife habitat and the environment) and down-stream from the affected areas. Rivers and streams receive salt laden run-off and sediment as soil structure degrades and erosion occurs. The quality of water supplies for urban, livestock and domestic purposes deteriorates.
Rarely can one land manager solve a salinity problem. While sometimes causes and effects can be seen within a single property; mostly the cause and effects cross property boundaries. Everyone in a catchment is affected by the agricultural activities of others in it. Therefore effective salinity management requires a total catchment approach.
Dumping of clean or contaminated soil
Disposing of unwanted clean fill or contaminated soil is a challenge across all of Victoria, however this issue is compounded in the green wedges and peri-urban areas due to their proximity to metropolitan Melbourne. Unregulated soil and earth storage can negatively impact waterways, ecosystems, landscapes, habitat, and agricultural land.
Moving towards sustainable agriculture techniques
There have been many changes in agricultural management in recent decades, and while these have often resulted in positive soil health outcomes there is still a need to broaden the adoption of practices that protect and improve soil. In particular, reduction in tillage, retention of organic residues and control of stock traffic play key roles in improving soil structure and hydrological properties as well as maintaining or increasing yields. These “regenerative agriculture” practices also improve the ability of soils to capture atmospheric carbon. They hold significant potential for farming to participate in carbon trading markets. Adoption of these practices more widely will be supported by better information but there are areas where long–established practices work against these principles.
Vision and targets for the future
The National Soil Strategy includes the following vision:
Australia’s soil is recognised and valued as a key national asset by all stakeholders. It is better understood and sustainably managed, to benefit and secure our environment, economy, food, infrastructure, health, biodiversity, and communities – now and in the future.
Regional Catchment Strategy target
Contributing to the long term achievement of this vision, our broad regional target for soil health is outlined below.
Progress towards this target will be monitored by accessing the assessments undertaken each year through the Australian National University.
Target 8.1 – Exposed soil
The following organisations formally support the pursuit of the visions and targets for soil health. They have agreed to provide leadership and support to help achieve optimum results with their available resources, in ways such as:
- Fostering partnerships and sharing knowledge, experiences and information with other organisations and the community
- Seeking and securing resources for the area and undertaking work that will contribute to achieving the visions and targets
- Assisting with monitoring and reporting on the condition of the area.
- Port Phillip & Westernport Catchment Management Authority
- Agriculture Victoria – Department of Jobs, Precincts and Regions
- Trust for Nature
- Melbourne Water
- Environment Protection Authority Victoria (EPA)
- Sustainability Victoria
- Hume City Council
- Macedon Ranges Shire Council
- Wyndham City
- Western Alliance for Greenhouse Action
- City of Greater Dandenong
- City of Casey
- South Gippsland Shire Council
- Wadawurrung Traditional Owners Aboriginal Corporation
- The Nature Conservancy
- OzFish Unlimited
- The People and Parks Foundation
- Friends of Lower Kororoit Creek Inc
- Werribee River Association
- Federation for Environment and Horticulture in the Macedon Ranges
- Nillumbik Landcare Network
- Yarra Ranges Landcare Network
- Northern Yarra Landcare Network
- Nangana Landcare Network
- Johns Hill Landcare Group
- Kooyongkoot Alliance
- Friends of Olinda Creek
- Abbotsford Riverbankers Inc
- Mornington Peninsula Landcare Network
- Main Creek Catchment Landcare Group
- Westernport Swamp Landcare Group
- Bass Coast Landcare Network
- South Gippsland Landcare Network
- Loch-Nyora Landcare Group
- Mt. Lyall Landcare Group
- Poowong & District Landcare Group
- Triholm Landcare Group
Add your organisation as a supporter and partner
If your organisation supports these directions and targets for soil health and wishes to be listed as a partner organisation, you can request to be listed as a partner organisation. Adding your organisation to this list will:
- Enable your organisation to list one or more priority projects in the Prospectus which will describe how your priority project will pursue the targets of this Regional Catchment Strategy and potentially make your organisation’s project more attractive to investors by using the strategy to highlight its relevance and value
- Demonstrate your commitment to a healthy and sustainable environment
- Demonstrate the level of community engagement and support for this work.
Priority projects to move forward
There are significant ongoing programs and initiatives undertaken by many organisations in this region that are vital for protecting and enhancing soil health and are priorities to continue. In addition, there are numerous project proposals that, if funded and implemented, can contribute to achieving the Regional Catchment Strategy’s visions and targets. Project proposals include:
- Fert$mart led by GippsDairy
- Soil, Water and Biodiversity Stewardship on Farms proposed by the Port Phillip & Westernport Catchment Management Authority
- Regenerative agriculture skills and capacity development proposed by the Mornington Peninsula Shire Council.
A full list of project proposals across the region and their key details can be viewed on the Prospectus section of this website.
Propose a new priority project
As part of the ongoing development and refinement of this Regional Catchment Strategy, additional priority projects may be considered for inclusion in the Prospectus.
If your organisation supports the directions and targets for soil health, and has a project it would like highlighted and supported in this Regional Catchment Strategy, please submit a Prospectus Project Proposal.