Type of indicator

Environment

Indicator C41

Soil organic carbon in arable land

Definition 

The indicator estimates the total organic carbon content in arable soils. 

It consists of 2 sub-indicators:

1 .the total estimate of organic carbon content in arable land

2. the mean organic carbon content

Soil organic carbon, the major component of soil organic matter, is extremely important in all soil processes. Organic matter in the soil is essentially derived from residual plant tissues, while microbial, fungal and animal contributions constitute a small part of its total amount. Microbes, fungi and animals decompose organic matter more or less efficiently depending on temperature, moisture and ambient soil conditions. The annual rate of loss of organic matter can vary greatly, depending on cultivation practices, the type of plant/crop cover, drainage status of the soil and weather conditions. There are two groups of factors that influence inherent organic matter content: natural factors (climate, soil parent material, land cover and/or vegetation and topography), and human-induced factors (land use, management and degradation) (de Brogniez, D., Ballabio, C., Stevens, A., Jones, R. J. A., Montanarella, L. and van Wesemael, B. (2014), A map of the topsoil organic carbon content of Europe generated by a generalized additive model. European Journal of Soil Science.)

The indicator is expressed as an estimate of the total Soil Organic Carbon stocks in topsoil (0-20) of EU Member States. 

The mean Soil Organic Carbon concentration per Member State is calculated, though solely for orientation purposes since it has very limited scientific meaning given the high variability of Soil Organic Carbon concentration in different areas. 

The following  indicators on soil quality also exist: 

- Agro-environmental indicator (AEI 26) Soil Quality: http://ec.europa.eu/eurostat/statistics-explained/index.php/Agri-environmental_indicator_-_soil_quality

Methodology:
 The indicator is based on the map of topsoil organic carbon content at the European scale elaborated by the Joint Research Centre of the European Commission. The map is based on estimates calculated by applying digital soil mapping techniques to the first European harmonized geo-references topsoil (0-20 cm) database, which arises from the Land Use/Cover Area frame statistical Survey(LUCAS), 2015.

LUCAS is a field survey programme to monitor changes in the management and nature of the land surface of the European Union. It is also used for the collection of soil samples and their subsequent analysis to produce updated and harmonised maps of relevant soil parameters, including topsoil organic carbon (0-20 cm). 

The map produced gives the most up-to-date general picture of topsoil organic carbon content at the European Union scale and is not intended to be a substitute for national scale or local maps that are based on more detailed spatial information. Moreover, it is important that the uncertainty associated with the predicted values is understood by the end-users and should encourage careful use and interpretation of the spatial values. The maps produced in this study will be freely available for download from the European Soil Data Centre website http://eusoils.jrc.ec.europa.eu/

Unit of measurement

1: megatonnes (Mt);

2: g/kg.

Data source

- Joint Research Centre (JRC Ispra) – Map of Topsoil Organic Carbon Content of Europe based on Land use/cover Area frame statistical Survey (LUCAS), (current version: 2015). The map is elaborated by the European Soil Database hosted by the Joint Research Centre;

- de Brogniez, D., Ballabio, C., Stevens, A., Jones, R. J. A., Montanarella, L. and van Wesemael, B. (2014), A map of the topsoil organic carbon content of Europe generated by a generalized additive model. European Journal of Soil Science. doi: 10.1111/ejss.12193;

Other sources: Potential sources available at national level (studies, surveys, reports), models and estimation (e.g. AEIs).

References/location of the data

The Map of Topsoil Organic Carbon Content is available on the European Soil Datacentre hosted by the Joint Research Centre http://eusoils.jrc.ec.europa.eu/

Other sources: National studies, surveys, reports

Data collection level

National (NUTS 0), regional (NUTS 2).

Frequency

The map is regularly updated depending on the availability of new data (the current version of the map is based on the 2015 LUCAS soil survey results.

LUCAS survey is in principle carried out every three years. If this frequency is maintained in future, it could be envisaged that every second or third LUCAS survey (i.e. every six to nine years) a soil module could be added to determine changes compared to the 2009-2012 baseline. 

Delay

The expected delay between soil sampling and the publication of the results is about 2-3 years.

Comments/caveats