Skip to content | Last Update: Wednesday, 16 July 2008
Central West CMA House Banner
Contact Us | Search this Site
  1. Home
  2. Soil Management
Contact Print this page Reduce font size Increase font size

Central West CMA Logo Icon Soil

Australian soils are amongst the most ancient and fragile in the world, requiring knowledgeable, careful management. They often have naturally low fertility, with most of their nutrients for plant growth and biodiversity being close to the surface.

Stable, healthy and productive soil and landscapes are essential for producing much of our food and fibre, maintaining water quality, sustaining primary industries, and supporting rural and urban development. Over the first two centuries of European settlement in Australia, some common practices for land use proved to be inappropriate, significantly altering our land and leading to degradation through problems such as acidification, salinity and erosion.

Central West - Programs - Soil - Top Soil Loss due to Erosion

The tree root demonstrates topsoil loss due to wind and water erosion.

 

Our State's rural landscape is under continuing pressure. Acidification, salinity, erosion, invasive native scrub, and loss of native vegetation are together having a serious effect on the condition of our soil, and on the communities and industries that depend on it. Without action, the situation will continue to deteriorate.

In recent years, however, advances in science and farming techniques have given us a far better understanding of our land resources. Australians now acknowledge the need to change some of our past practices, to take account of our unique landscape, and to use and manage our natural resources in a sustainable way. Effective management of the land to prevent and remediate damage relies on access to up-to-date, comprehensive information on the state's soil and natural landscapes.

Over the next 10 years the Central West CMA has planned to make significant improvements to soil management within the catchment. Key management targets to achieve this include;

  • Widespread incorporation of perennial pastures into agricultural areas

  • Adoption of best management practices for soil

  • Management of Lands using Integrated Management Plans

  • Management of woody weed areas to increase biodiversity and improve landscape function and

  • Improvements to sodic soil structure and restoration of vegetation cover in saline areas.

The catchment and management targets to improve soil management and reduce further degradation and structural decline are listed below. The Catchment Action Plan and Summary documents provide more detailed explanations on the critical thresholds for soil health.

 

Central West - Programs - Soil Erosion of former Wheat Paddock

Soil Erosion site in the upper catchment. This site used to be a premier site for wheat yield.

 

 

Catchment and Management Target Overview till 2016:

Catchment Target (CTSS1):

  • By 2016, 1,600,000 ha (20%) of agricultural land in the catchment is managed to meet critical thresholds for a range of landscape specific criteria – refer to table in detail section.

Management Target (MTSS1):

  • By 2016, 50,000ha of the catchment will be managed to have a desirable perennial plant component for landscape protection.

Management Target (MTSS2):

  • By 2016, 690,000ha of cropping land is managed using Best Management Practice for soil health.

Management Target (MTSS3):

  • By 2016, 1,000,000ha of land is managed under integrated property management plans (PMP’s)

Management Target (MTSS4):

  • By 2016, 20,000ha of woody weed dominant areas are managed for increased biodiversity and improved landscape function.

Management Target (MTSS5):

  • By 2016, 12,000ha of sodic soils are managed to improve soil structure and to restore productive vegetation cover.

 

 

Targets in detail:

The soils targets meet the following Natural Resources Commission's Statewide Targets as referenced in the Catchment Action Plan:

  • Community Targets - 12, 13, 14;
  • Water Targets - 5; Land 10, 11.

 

Catchment Target (CTSS1):

  • The intent of this target is to improve soil health by adopting management practices, which will increase the efficiency and future sustainability of agricultural enterprises whilst reducing the extent of land degradation. There is an estimated 8,000,000ha of agricultural land in the Central West catchment. The measurement of soil health could not be based on a single parameter.
  • The catchment target focuses on four critical aspects of soil health that can be used as surrogates for a full soil health index. The target refers to land units and varies the target levels according to this. The land units reflect the amalgamation of soil groups and geology attributes.

 

Land Unit / Soil Type

Herbage Mass5, 6 (levels measured at April)

Soil Acidity (CaCl2)

Bare Land (cultivated, burnt or grazed at end of March)

Soil Organic

Perennial Pasture Component 6

TABLELANDS

 

 

 

 

 

Basalt/ Basic

A minimum of 1 tonne/ha dry matter

Prevent falling below pH 5.5 2

< 10%

25% improvement in organic carbon levels in top 5cm of soil

40%

Intermediate

 

Maintain at least 25% of area above pH 5.5

< 10%

 

 

Siliceous/ Sedimentary

 

Naturally acidic 1

0%

 

 

Shallow

 

Naturally acidic 1

0%

 

 

Alluvial

 

Little Hazard

N/A 3

 

 

SLOPES

 

 

 

 

 

Basalt/ Basic

A minimum of 1 tonne/ha dry matter

Prevent falling below pH 5.5 2

<20%

25% improvement in organic carbon levels in top 5cm of soil

40%

Intermediate

 

Maintain at least 40% of area above pH 5.5

 

Siliceous/ Sedimentary

 

Maintain at least 40% of area above pH 5.0

 

Shallow

 

Little Hazard

0%

 

 

Alluvial

 

Little Hazard

N/A 3

 

 

PLAINS

 

 

 

 

 

Shallow

A minimum of 0.5 tonne/ha dry matter

Little Hazard

0%

Maintain and improve current organic carbon levels

40%

Self-mulching

 

Little Hazard

Little Hazard

 

 

Sodic Clay

 

Maintain pH above 5.0 at least 50% of the time

< 30% cultivated4

 

 

Hard Red

 

Maintain pH above 5.0 at least 50% of the time

< 30% cultivated4

 

 

Soft Red

 

Little Hazard

 

 
  1. naturally acidic soils that require alternative techniques to manage soil acidity (acid tolerant species, increasing organic matter)
  2. Potential for induced acidity if not managed correctly
  3. Require specific techniques to manage soil structure ( controlled traffic, raised beds etc)
  4. Requires specific techniques, such as chisel ploughing (non-inversion), controlled traffic, raised beds etc to allow moisture infiltration on soils with structural decline
  5. Herbage mass can be increased through total grazing management and stubble management
  6. To meet critical thresholds 75% of the time

Table 1: Proposed landscape targets for critical thresholds for agricultural land.

 

Clarification of Terms:

CRITICAL THRESHOLDS:

  • the identified upper limits to pressure on the resource before a permanent detrimental effect results.

HERBAGE MASS:

  • The oven dried weight of vegetative ground cover above the soil surface measured in tonnes/hectare.

SOIL ACIDITY:

  • Soil with pH producing metal toxicity and/or nutrient deficiency that may result in plant cover decline and an increase in erosion hazard.

CULTIVATION/BARE SOIL:

  • Area of soil without vegetative cover measured in March each year – erosive risk. ORGANIC CARBON: A measure of the proportion of organic material in the soil profile.

 

 

Management Target (MTSS1):

  • By 2016, 50,000ha of the catchment will be managed to have a desirable perennial plant component for landscape protection. The intent of this target is to achieve a higher percentage of desirable perennial species in permanent pastures to achieve biomass targets and minimise water movement through the soil profile.
  • Minimising water movement will help prevent the leaching of salts (salinity) and nitrate (acidity) in or through the root zone. Desirable plants will differ across enterprises and the catchment, but does not include noxious weeds, environmental weeds or woody weeds.
  • In addition, increased perenniality will increase the level of vegetative cover which will also reduce soil erosion and improve soil health (soil structure, biological activity and nutrients). This target includes useful shrubs and forbs, such as native saltbush in the plain areas.

 

Clarification of Terms:

DESIRABLE PERENNIAL PLANT:

  • Perennial species that contributes to economic and environmental sustainability by improving soil health, increasing water use, maintaining ground cover and maintaining or improving animal health and productivity. It can be either a native or introduced species

 

 

Management Target (MTSS2):

  • By 2016, 690,000ha of cropping land is managed using Best Management Practice for soil health. The intent of the target is to improve the structure of soils through improved cropping practices. There are large areas of cultivated soils in the catchment and many of these areas have been degraded over time.
  • Changes in cropping systems can increase the level of herbage mass and organic material and improve the soil structure and soil biology and improve water quality by reducing soil loss in storm events. An advantage of this approach is that it can reduce costs of cropping, maintains productivity and ensures the long-term sustainability of cropping.

 

 

Management Target (MTSS3):

  • By 2016, 1,000,000ha of land is managed under integrated property management plans (PMP’s) The intent of the target is to encourage and support land managers to undertake planning activities to assist in the adoption of best management practices across all aspects of farm management, including environmental and economic.

 

Clarification of Terms:

INTEGRATED PMP:

  • A plan developed through an accredited process that identifies specific management practices suitable for production and conservation activities on a property to ensure sustainable productivity and enhance soil health. An integrated plan should also address vegetation, water and other natural resource management issues and aim to balance production and conservation outcomes to ensure sustainability.

 

 

Management Target (MTSS4):

  • By 2016, 20,000ha of woody weed dominant areas are managed for increased biodiversity and improved landscape function. The intent of the target is to reduce the erosion risk under woody weeds. Woody weed dominant areas often have little groundcover due to the high demand for moisture and available nutrient and the shading effect of the woody species.
  • The bare soil is at high risk of erosion from run-off events. This is a particular problem in low rainfall areas of the catchment where there is insufficient soil moisture to sustain groundcover. The implementation of this target will require compliance with the Invasive Native Species module of the Property Vegetation Plan (PVP) Developer.

 

Clarification of Terms:

WOODY WEED DOMINANT AREA:

  • Generally refers to areas of high-density native regrowth. Examples of such regrowth include eucalypt, acacia and pine communities.

 

 

Management Target (MTSS5):

  • By 2016, 12,000ha of sodic soils are managed to improve soil structure and to restore productive vegetation cover. The intent of the target is to improve the structure of sodic soils by improving grazing strategies, application of ameliorants and reduced tillage cropping systems.
  • There are large areas of sodic soils in the catchment and many of these areas have degraded over time. Changes in land management can increase the level of herbage mass and perennial plant cover, improve soil structure and soil biology and improve water quality.

 

Clarification of Terms:

SODIC SOIL:

  • A soil containing sufficient exchangeable sodium to adversely affect stability and result in soil becoming readily dispersible. Degraded sodic soils have very poor structure and are usually bare or only sustain sparse annual pastures.

 

Further Information:

If you would like more information from the Central West CMA please email: cw@cma.nsw.gov.au

Contact Print this page Reduce font size Increase font size