State and trends of soil carbon

Component
Summary
Grade
Very poor Poor Good Very good
Confidence
In Grade In Trend
Comparability
To previous years

Rangelands with extensive grazing and wind-borne soil erosion, particularly on sandplains. In western New South Wales, 74% of soil monitoring units report SOC reduction as an issue

Year(s): 
2016
3
Deteriorating
Confidence (in grade): 
Somewhat adequate
Confidence (in trend): 
Somewhat adequate
Comparability (to previous reports): 
Somewhat comparable

Rangelands with extensive grazing and soil erosion caused by wind particularly on sandplains

Year(s): 
2011
3
Deteriorating
Confidence (in grade): 
Limited
Confidence (in trend): 
Limited
Comparability (to previous reports): 
Not assessed

Rangelands with minor opportunity cropping. In western NSW, 74% of soil monitoring units report SOC reduction as an issue

Year(s): 
2016
2
Unclear
Confidence (in grade): 
Somewhat adequate
Confidence (in trend): 
Somewhat adequate
Comparability (to previous reports): 
Somewhat comparable

Rangelands with minor opportunity cropping

Year(s): 
2011
2
Deteriorating
Confidence (in grade): 
Limited
Confidence (in trend): 
Limited
Comparability (to previous reports): 
Not assessed

Grazing of modified and natural pastures, and nature conservation are major land uses. In the Central Plateau of NSW, 33% of soil monitoring units report SOC reduction as an issue

Year(s): 
2016
2
Deteriorating
Confidence (in grade): 
Somewhat adequate
Confidence (in trend): 
Somewhat adequate
Comparability (to previous reports): 
Somewhat comparable

Land used for grazing of modified and natural pastures and nature conservation. Significant losses of soil carbon, particularly in the east

Year(s): 
2011
3
Deteriorating
Confidence (in grade): 
Limited
Confidence (in trend): 
Limited
Comparability (to previous reports): 
Not assessed

Infertile coastal lowlands used for forestry, grazing, cropping and some nature conservation. In the North Coast region of New South Wales, 56% of soil monitoring units report SOC reduction as an issue

Year(s): 
2016
2
Deteriorating
Confidence (in grade): 
Somewhat adequate
Confidence (in trend): 
Somewhat adequate
Comparability (to previous reports): 
Somewhat comparable

Infertile coastal lowlands used for forestry, grazing, cropping and some nature conservation

Year(s): 
2011
2
Deteriorating
Confidence (in grade): 
Adequate
Confidence (in trend): 
Limited
Comparability (to previous reports): 
Not assessed

Historically poor management has depleted SOC. Overgrazing by feral goats is causing further decline, despite improving land management. In western New South Wales, 74% of soil monitoring units report SOC reduction as an issue

Year(s): 
2016
2
Deteriorating
Confidence (in grade): 
Somewhat adequate
Confidence (in trend): 
Somewhat adequate
Comparability (to previous reports): 
Somewhat comparable

Significant declines in soil carbon, mostly associated with historically poor management. Overgrazing by feral goats is causing further decline, despite improving land management

Year(s): 
2011
3
Deteriorating
Confidence (in grade): 
Limited
Confidence (in trend): 
Limited
Comparability (to previous reports): 
Not assessed

Surface SOC is low as a result of grazing and prior clearing. In the Central Tablelands region of New South Wales, 40% of soil monitoring units report SOC reduction as an issue

Year(s): 
2016
2
Deteriorating
Confidence (in grade): 
Somewhat adequate
Confidence (in trend): 
Somewhat adequate
Comparability (to previous reports): 
Somewhat comparable

Surface content of carbon declining due to grazing and prior clearing

Year(s): 
2011
2
Deteriorating
Confidence (in grade): 
Limited
Confidence (in trend): 
Limited
Comparability (to previous reports): 
Not assessed

Declining trend due to intensification of cropping. In the north-west region of New South Wales, 18% of soil monitoring units report SOC reduction as an issue

Year(s): 
2016
2
Unclear
Confidence (in grade): 
Somewhat adequate
Confidence (in trend): 
Somewhat adequate
Comparability (to previous reports): 
Somewhat comparable

Declining trend due to intensification of cropping

Year(s): 
2011
2
Deteriorating
Confidence (in grade): 
Limited
Confidence (in trend): 
Limited
Comparability (to previous reports): 
Not assessed

Area used for nature conservation and production forestry, with some grazing. Possible decline in SOC due to logging. In the Hunter region of New South Wales, 50% of soil monitoring units report SOC reduction as an issue

Year(s): 
2016
3
Unclear
Confidence (in grade): 
Somewhat adequate
Confidence (in trend): 
Somewhat adequate
Comparability (to previous reports): 
Somewhat comparable

Area used for nature conservation and production forestry, with some grazing. Possible decline due to logging

Year(s): 
2011
3
Deteriorating
Confidence (in grade): 
Limited
Confidence (in trend): 
Limited
Comparability (to previous reports): 
Not assessed

Mixed farming on naturally fertile Ferrosols and Vertosols. In the Hunter region of New South Wales, 50% of soil monitoring units report SOC reduction as an issue

Year(s): 
2016
4
Unclear
Confidence (in grade): 
Somewhat adequate
Confidence (in trend): 
Somewhat adequate
Comparability (to previous reports): 
Somewhat comparable

Mixed farming on fertile Ferrosols and Vertosols

Year(s): 
2011
4
Improving
Confidence (in grade): 
Adequate
Confidence (in trend): 
Limited
Comparability (to previous reports): 
Not assessed

Soils are Sodosols and Vertosols, used for cropping and grazing. in the Central West region of New South Wales, 19% of soil monitoring units report SOC reduction as an issue

Year(s): 
2016
2
Unclear
Confidence (in grade): 
Somewhat adequate
Confidence (in trend): 
Somewhat adequate
Comparability (to previous reports): 
Somewhat comparable

Sodosols and Vertosols used for cropping and grazing

Year(s): 
2011
2
Deteriorating
Confidence (in grade): 
Limited
Confidence (in trend): 
Limited
Comparability (to previous reports): 
Not assessed

Grazing of modified and natural pastures dominates. In the Central Tablelands region of New South Wales, 40% of soil monitoring units report SOC reduction as an issue

Year(s): 
2016
2
Unclear
Confidence (in grade): 
Somewhat adequate
Confidence (in trend): 
Somewhat adequate
Comparability (to previous reports): 
Somewhat comparable

Grazing of modified and natural pastures dominates. General improvement in land management practices

Year(s): 
2011
2
Improving
Confidence (in grade): 
Limited
Confidence (in trend): 
Limited
Comparability (to previous reports): 
Not assessed

Diverse landscape with natural conservation, forestry, grazing, horticulture and urban land uses. Fire regime and land management practices are most likely causing a decline in SOC. In the Greater Sydney region of New South Wales, 57% of soil monitoring units report SOC reduction as an issue

Year(s): 
2016
3
Deteriorating
Confidence (in grade): 
Somewhat adequate
Confidence (in trend): 
Somewhat adequate
Comparability (to previous reports): 
Somewhat comparable

Diverse landscape with natural conservation, forestry, grazing, horticulture and urban land uses. Fire regime and land management practices are most likely causing a decline

Year(s): 
2011
3
Deteriorating
Confidence (in grade): 
Limited
Confidence (in trend): 
Limited
Comparability (to previous reports): 
Not assessed

Mostly urban and industrial land use. In the Greater Sydney region of New South Wales, 57% of soil monitoring units report SOC reduction as an issue

Year(s): 
2016
2
Unclear
Confidence (in grade): 
Somewhat adequate
Confidence (in trend): 
Somewhat adequate
Comparability (to previous reports): 
Somewhat comparable

Mostly urban and industrial land use

Year(s): 
2011
2
Deteriorating
Confidence (in grade): 
Limited
Confidence (in trend): 
Limited
Comparability (to previous reports): 
Not assessed

In the South East region of New South Wales, 59% of soil monitoring units report SOC reduction as an issue. No data from the Australian Capital Territory

Year(s): 
2016
3
Deteriorating
Confidence (in grade): 
Somewhat adequate
Confidence (in trend): 
Somewhat adequate
Comparability (to previous reports): 
Somewhat comparable

Relatively infertile lands used for grazing. Suspected slight decline

Year(s): 
2011
4
Deteriorating
Confidence (in grade): 
Limited
Confidence (in trend): 
Limited
Comparability (to previous reports): 
Not assessed

Good levels of SOC under nature conservation, forestry, and grazing. Land management is improving

Year(s): 
2016
3
Unclear
Confidence (in grade): 
Somewhat adequate
Confidence (in trend): 
Somewhat adequate
Comparability (to previous reports): 
Somewhat comparable

Forestry, nature conservation and grazing. Land management is improving

Year(s): 
2011
3
Improving
Confidence (in grade): 
Limited
Confidence (in trend): 
Limited
Comparability (to previous reports): 
Not assessed

Mostly used for nature conservation. Controls on grazing and reduced erosion stabilised early losses, but the increased intensity and extent of fires are likely to be causing a decrease, particularly in Organosols

Year(s): 
2016
4
Unclear
Confidence (in grade): 
Somewhat adequate
Confidence (in trend): 
Somewhat adequate
Comparability (to previous reports): 
Somewhat comparable

Mostly used for nature conservation. Controls on grazing and reduced erosion stabilised early losses, but the increased intensity and extent of fires are likely to be causing a slight decrease, particularly in Organosols

Year(s): 
2011
4
Deteriorating
Confidence (in grade): 
Limited
Confidence (in trend): 
Limited
Comparability (to previous reports): 
Not assessed

Cropping, grazing and nature conservation with irrigated agriculture along the Murray River. Improved farming practices have improved soil condition in some areas

Year(s): 
2016
2
Unclear
Confidence (in grade): 
Somewhat adequate
Confidence (in trend): 
Somewhat adequate
Comparability (to previous reports): 
Somewhat comparable

Cropping, grazing and nature conservation with irrigated agriculture along the Murray River. Improved farming practices have improved soil condition in some areas, but soil carbon levels are probably still declining

Year(s): 
2011
2
Deteriorating
Confidence (in grade): 
Limited
Confidence (in trend): 
Limited
Comparability (to previous reports): 
Not assessed

Mainly cropping and grazing. Former grazing lands now used for nature conservation may still be experiencing declining carbon content. Changing farming practices to no-till may be increasing SOC content in some areas, especially on heavier soils

Year(s): 
2016
2
Unclear
Confidence (in grade): 
Somewhat adequate
Confidence (in trend): 
Somewhat adequate
Comparability (to previous reports): 
Somewhat comparable

Mainly cropping and grazing. Former grazing lands now used for nature conservation may still be experiencing declining carbon content. Changing farming practices to no-till may reduce soil carbon loss in some areas, especially on heavier soils. Soil carbon is still likely to be declining in this region

Year(s): 
2011
2
Deteriorating
Confidence (in grade): 
Limited
Confidence (in trend): 
Limited
Comparability (to previous reports): 
Not assessed

Dryland cropping and irrigated agriculture, with grazing in the west. None of the soil monitoring units in the Riverina region of New South Wales reported SOC as an issue

Year(s): 
2016
2
Unclear
Confidence (in grade): 
Somewhat adequate
Confidence (in trend): 
Somewhat adequate
Comparability (to previous reports): 
Somewhat comparable

Dryland cropping, irrigated agriculture and grazing, with the latter dominant in the west. Slight declines under dryland cropping systems, although farming practices may halt this

Year(s): 
2011
2
Deteriorating
Confidence (in grade): 
Limited
Confidence (in trend): 
Limited
Comparability (to previous reports): 
Not assessed

Grazing, cropping and expanding plantation forestry. Areas converted from pasture to cropland are probably declining, as are soils used for continuous cropping

Year(s): 
2016
3
Unclear
Confidence (in grade): 
Very limited
Confidence (in trend): 
Low
Comparability (to previous reports): 
Somewhat comparable

Grazing, cropping and expanding plantation forestry. Areas converted from pasture to cropland are probably declining, as are soils used for continuous cropping

Year(s): 
2011
3
Deteriorating
Confidence (in grade): 
Limited
Confidence (in trend): 
Limited
Comparability (to previous reports): 
Not assessed

Dryland cropping, grazing and increasing irrigated cropping. Intensification of cropping is probably causing a decline in SOC

Year(s): 
2016
3
Unclear
Confidence (in grade): 
Very limited
Confidence (in trend): 
Low
Comparability (to previous reports): 
Somewhat comparable

Dryland cropping, grazing and increasing irrigated cropping. Intensification of cropping is causing the decline

Year(s): 
2011
3
Deteriorating
Confidence (in grade): 
Limited
Confidence (in trend): 
Limited
Comparability (to previous reports): 
Not assessed

Nature conservation reserves. Where wildfire and grazing have resulted in sheet erosion over large areas, SOC has been lost, with limited potential for recovery

Year(s): 
2016
3
Unclear
Confidence (in grade): 
Very limited
Confidence (in trend): 
Low
Comparability (to previous reports): 
Somewhat comparable

Nature conservation reserves where wildfire and grazing have initiated sheet erosion over large areas, with very limited potential for recovery

Year(s): 
2011
3
Deteriorating
Confidence (in grade): 
Limited
Confidence (in trend): 
Limited
Comparability (to previous reports): 
Not assessed

More frequent and/or hotter fires in conservation reserves are causing losses, especially in Organosols. Production forestry in the north suggests little potential for increase in SOC sequestration

Year(s): 
2016
3
Unclear
Confidence (in grade): 
Very limited
Confidence (in trend): 
Low
Comparability (to previous reports): 
Somewhat comparable

More frequent and/or hotter fires in conservation reserves are causing losses, especially in Organosols. Northern areas dominated by production forestry, with no potential for soil carbon sequestration

Year(s): 
2011
3
Deteriorating
Confidence (in grade): 
Limited
Confidence (in trend): 
Limited
Comparability (to previous reports): 
Not assessed

Production and plantation forestry, with minor decline due to erosion. Irrigated cropping in the south-east and north-east is causing a decline in SOC

Year(s): 
2016
3
Unclear
Confidence (in grade): 
Very limited
Confidence (in trend): 
Low
Comparability (to previous reports): 
Somewhat comparable

Production and plantation forestry, with minor declines due to erosion. Irrigated cropping in the south-east and north-east is causing declines

Year(s): 
2011
3
Unclear
Confidence (in grade): 
Limited
Confidence (in trend): 
Limited
Comparability (to previous reports): 
Not assessed

Decline in SOC is associated with irrigated cropping

Year(s): 
2016
3
Unclear
Confidence (in grade): 
Very limited
Confidence (in trend): 
Low
Comparability (to previous reports): 
Somewhat comparable

Decline is associated with irrigated cropping

Year(s): 
2011
3
Deteriorating
Confidence (in grade): 
Adequate
Confidence (in trend): 
Adequate
Comparability (to previous reports): 
Not assessed

Mainly grazing of native vegetation. Shift from perennials to annuals and possible increase in fire frequency may lead to decline in SOC

Year(s): 
2016
3
Unclear
Confidence (in grade): 
Limited
Confidence (in trend): 
Low
Comparability (to previous reports): 
Somewhat comparable

Mainly grazing of native vegetation. Shift from perennials to annuals and possible increase in fire frequency may lead to nominal decline

Year(s): 
2011
3
Deteriorating
Confidence (in grade): 
Limited
Confidence (in trend): 
Limited
Comparability (to previous reports): 
Not assessed

SOC decline is restricted to pastoral areas

Year(s): 
2016
3
Unclear
Confidence (in grade): 
Limited
Confidence (in trend): 
Low
Comparability (to previous reports): 
Somewhat comparable

Soil carbon decline restricted to pastoral areas

Year(s): 
2011
3
Deteriorating
Confidence (in grade): 
Limited
Confidence (in trend): 
Limited
Comparability (to previous reports): 
Not assessed

Urban areas and intensive agriculture. High levels of SOC are often associated with irrigated pasture. Decline in SOC is likely under intensive horticultural systems

Year(s): 
2016
3
Unclear
Confidence (in grade): 
Limited
Confidence (in trend): 
Low
Comparability (to previous reports): 
Somewhat comparable

Urban areas and intensive agriculture. Declines due to tillage. Irrigated pasture systems for dairy may be stable or increasing

Year(s): 
2011
3
Deteriorating
Confidence (in grade): 
Limited
Confidence (in trend): 
Limited
Comparability (to previous reports): 
Not assessed

Low input cropping and grazing. Drying trends have compounded effects of clearing and cropping on SOC loss

Year(s): 
2016
3
Unclear
Confidence (in grade): 
Limited
Confidence (in trend): 
Low
Comparability (to previous reports): 
Somewhat comparable

Low input cropping and grazing. Drying trends have compounded effects of clearing and cropping on soil carbon

Year(s): 
2011
3
Deteriorating
Confidence (in grade): 
Limited
Confidence (in trend): 
Limited
Comparability (to previous reports): 
Not assessed

Areas with extensive grazing of native vegetation, with declines in SOC in more heavily grazed areas. Few data in driest areas

Year(s): 
2016
2
Unclear
Confidence (in grade): 
Very limited
Confidence (in trend): 
Low
Comparability (to previous reports): 
Somewhat comparable

Areas with extensive grazing of native vegetation, with declines in more heavily grazed areas. Drying trends are an additional factor

Year(s): 
2011
2
Deteriorating
Confidence (in grade): 
Limited
Confidence (in trend): 
Limited
Comparability (to previous reports): 
Not assessed

Nature conservation, extensive grazing; small areas of intensive irrigated horticulture likely to have a decline in SOC

Year(s): 
2016
3
Unclear
Confidence (in grade): 
Very limited
Confidence (in trend): 
Low
Comparability (to previous reports): 
Somewhat comparable

Nature conservation, extensive grazing and small areas of intensive irrigated horticulture. Episodic removal of surface soil carbon in horticultural areas

Year(s): 
2011
3
Deteriorating
Confidence (in grade): 
Limited
Confidence (in trend): 
Limited
Comparability (to previous reports): 
Not assessed

Extensive grazing of native vegetation

Year(s): 
2016
3
Unclear
Confidence (in grade): 
Very limited
Confidence (in trend): 
Low
Comparability (to previous reports): 
Somewhat comparable

Extensive grazing of native vegetation

Year(s): 
2011
3
Deteriorating
Confidence (in grade): 
Limited
Confidence (in trend): 
Limited
Comparability (to previous reports): 
Not assessed

Small areas of intensive agriculture are likely to have declining SOC. Remainder is used for extensive grazing

Year(s): 
2016
4
Unclear
Confidence (in grade): 
Very limited
Confidence (in trend): 
Low
Comparability (to previous reports): 
Somewhat comparable

Small areas of intensive agriculture likely to have declining carbon. Remainder is used for extensive grazing

Year(s): 
2011
4
Deteriorating
Confidence (in grade): 
Limited
Confidence (in trend): 
Limited
Comparability (to previous reports): 
Not assessed

Extensive grazing, with small areas of more intensive development on better soils. Possible minor decreases in SOC due to high seasonal stocking rates

Year(s): 
2016
4
Unclear
Confidence (in grade): 
Very limited
Confidence (in trend): 
Low
Comparability (to previous reports): 
Somewhat comparable

Extensive grazing with small areas of more intensive development on better soils. Possible minor decreases in soil carbon due to high seasonal stocking rates

Year(s): 
2011
4
Deteriorating
Confidence (in grade): 
Limited
Confidence (in trend): 
Limited
Comparability (to previous reports): 
Not assessed

Extensive grazing on clay plains, with decline in SOC likely

Year(s): 
2016
4
Unclear
Confidence (in grade): 
Very limited
Confidence (in trend): 
Low
Comparability (to previous reports): 
Somewhat comparable

Extensive grazing on clay plains. Some impacts on soil carbon due to grazing

Year(s): 
2011
4
Deteriorating
Confidence (in grade): 
Limited
Confidence (in trend): 
Limited
Comparability (to previous reports): 
Not assessed

Ferrosols used for cropping and pasture, with increasing agroforestry. Slow recovery after large historical loss of SOC

Year(s): 
2016
1
Unclear
Confidence (in grade): 
Very limited
Confidence (in trend): 
Low
Comparability (to previous reports): 
Somewhat comparable

Ferrosols used for cropping and pasture, with increasing agroforestry. Slow increases occurring under pasture and agroforestry

Year(s): 
2011
1
Improving
Confidence (in grade): 
Adequate
Confidence (in trend): 
Adequate
Comparability (to previous reports): 
Not assessed

Partially cleared grazing country. SOC is likely to be declining in recently cleared areas; otherwise stable

Year(s): 
2016
3
Unclear
Confidence (in grade): 
Very limited
Confidence (in trend): 
Low
Comparability (to previous reports): 
Somewhat comparable

Partially cleared grazing country. Soil carbon is likely to be declining where cleared recently, otherwise stable

Year(s): 
2011
3
Deteriorating
Confidence (in grade): 
Limited
Confidence (in trend): 
Limited
Comparability (to previous reports): 
Not assessed

Fertile land with high rainfall. Diverse land uses, with SOC now recovering under pastures and tree crops; it is likely still decreasing under small-grain and horticultural crops

Year(s): 
2016
2
Unclear
Confidence (in grade): 
Very limited
Confidence (in trend): 
Low
Comparability (to previous reports): 
Somewhat comparable

Fertile land with high rainfall. Diverse land uses, with soil carbon now increasing under pastures and tree crops. Stable under rainfed crops but still decreasing under small crops

Year(s): 
2011
2
Improving
Confidence (in grade): 
Adequate
Confidence (in trend): 
Limited
Comparability (to previous reports): 
Not assessed

Recently intensified land use after clearing; therefore, SOC is likely declining

Year(s): 
2016
2
Unclear
Confidence (in grade): 
Very limited
Confidence (in trend): 
Low
Comparability (to previous reports): 
Somewhat comparable

Recently intensified land use after clearing. Soil carbon likely to be declining

Year(s): 
2011
2
Deteriorating
Confidence (in grade): 
Limited
Confidence (in trend): 
Limited
Comparability (to previous reports): 
Not assessed
Metcalfe D, Bui E (2016). Land: State and trends of soil carbon. In: Australia state of the environment 2016, Australian Government Department of the Environment and Energy, Canberra, https://soe.environment.gov.au/assessment-summary-51-state-and-trends-soil-carbon-0, DOI 10.4226/94/58b6585f94911