Soil erosion risk in Europe (European Commission 2008)
Frans J.P.M. Kwaad
Keywords: soil conservation, soil erosion, erosion control, conservation tillage, erosiebestrijding, niet-kerende grondbewerking, Europe, Nederland, België, Zuid-Limburg
Soil erosion is as old as agriculture. Stated in simplest terms, conservation of the soil is a matter of using land as it should be used. Proper use of the land is governed by certain physical factors. When it is used without regard for these factors, the processes of waste begin. Certain factors of an economic and social character also influence the use of land. Men who farm the land must make a living. That is their most realistic and immediate concern. Economic need is a powerful factor in determining how they use the land, a factor that usually outweighs less urgent considerations of conservation. Social patterns likewise are a landuse factor. As they affect the interests of the individual operator, economic and social influences are as much a part of the problem of soil conservation as the purely physical processes through which soil is washed or blown away. These words, written by Bennett in 1939, are as valid today as they were seventy years ago.
Bennett, H.H., 1939. Soil Conservation.
McGraw-Hill Book Company, New York, 993 pp.
Soil erosion risk in Europe (European
Commission 2008)
PESERA: Pan European Soil Erosion Risk Assessment Map (Sources: Kirkby
and PESERA
)
Introduction
The state of the art of soil erosion research
in Europe has recently been described in great detail in the book Soil
Erosion in Europe . The present website is meant as an inventory and
overview of the current state of soil conservátion in Europe. The
intention is also to make existing information on soil erosion control
practices readily available to farmers, farmer's organisations, policy
makers and other interested parties in Europe. The site is a collection
of links to erosion control efforts in individual European countries that
can be found on the Internet. The site is far from complete. Many countries
are still lacking. Additions to the links below are therefore very welcome.
So, if you know of any initiatives or regulations to combat soil erosion
in Europe, please let me know. The site only deals with soil erosion by
rain, not by wind. It does not deal with other forms of soil degradation
than erosion.
Soil conservation in Europe has not generally received sufficient attention, until recently. In most European countries, scientific interest in soil erosion arose in the 1970's. This was due to: (a) changes in agriculture (larger fields, more row crops, heavier machines), leading to an aggravation of erosion, and (b) a growing interest among earth scientists in the rate of operation, controlling factors and mechanisms of the so-called landscape forming processes, such as slope wash or hill wash. In some countries, concern for soil erosion is (much) older, like in Iceland, Poland, Bulgaria, Moldavia and Portugal. Today, there is sufficient knowledge in Europe to apply erosion control techniques and to experiment with the efficacy of those available. Not enough is done, however. Much of the failure to address the on- and off-farm impacts of soil erosion is a result nót of technical inadequacy, but of a failure to recognise the importance of socio-economic factors in influencing erosion (Soil Erosion in Europe, p. 485).
Erosion (by rain) is a natural process on sloping land. It is the detachment and downslope displacement of soil particles by raindrop impact (splash) and running water (overland flow). Under natural vegetation (e.g.forest) the rate of erosion is very low. The vegetation protects the soil. This is called 'normal erosion' or the 'geologic norm of erosion'. When the natural vegetation is removed, as in arable farming, the soil is exposed to rainfall and the rate of erosion may increase 100-1000 fold, compared to forest. This is called 'accelerated erosion' or 'soil erosion'. Thus, soil erosion is an (unintended and unwanted) consequence or side effect of agriculture. Most farmers nowadays are aware of this and are willing to take measures to counteract erosion, in their own interest and that of others. There are costs involved, however, and it may be necessary to induce farmers to take action. Incentives may be in the form of regulations or legislation, together with financial compensation (subsidies, tax reduction). The most recent study (on a European level), how to encourage farmers to adopt soil conservation practices is the SoCo-project. It was launched by the European Commission for the period 2007-2009.
Legislation is not primarily enforced upon farmers because of the irreversible loss of fertile topsoil and damage to the land, but because of the so-called off-site effects that accompany the loss of soil from cultivated land. The soil that is washed away, is deposited as mud on roads, in roadside ditches, in culverts and sewers, in the gardens, basements and cellars of houses, in the streets of built-up and residential areas and in rivers, dams and reservoirs. So, there may be serious damage to public and private property outside agriculture. Soil erosion is often also accompanied by flooding, and water quality may be impaired by erosion-derived agrochemicals. Legislation only exists in a few European countries today.
Many measures to prevent or reduce soil erosion
are known since the 1930's, mostly developed in the USA. These measures
need to be adapted to local conditions of climate, soil, slope and field
length and the type of crop that is grown on the eroded fields. In general,
we have a fair understanding of the mechanisms and controlling factors
of soil erosion and of the basic principles of soil conservation. However,
applying this knowledge to a given local context seems to be difficult.
Empirical tests (on plot and field scale) with local crops and local farming
systems are necessary to establish conservation techniques that are effective
and feasible. It is here, that farmers and scientists must work together
and bring in their skill and expertise. Farmers can contribute their practical
experience in land management, and scientists their fundamental knowledge
of erosion processes and soil properties. This co-operation is best achieved
on experimental farms, where the different interests of farmers and scientists
may fruitfully come together. Ingram discusses in detail the different
outlooks of farmers and scientists in England, Switzerland and France on
soil erosion and conservation. This is a very important issue that may
complicate the application and implementation of erosion control measures
considerably. Click here
to read the paper. Most promising for the future seems to be so-called
conservation tillage, in its various forms (minimum tillage, zero tillage,
no till, direct drill, reduced tillage, strip till, mulch till, non-inverting
tillage).
Ephemeral gully crossing a number of
arable fields in the hilly loess district of Dutch South Limbourg after
55 mm of rain in 2 hours incl. 30 mm in 30 minutes (Photo D. Koeman).
Ground view of same ephemeral gully as above. The plough layer was washed
away on recently drilled fields (Photo F. Kwaad).
Gully erosion in loess soil in Dutch South Limbourg (Photo F. Kwaad).
Deposition of eroded soil in the corner of a sloping field in Dutch South
Limbourg (Photo F. Kwaad).
Mud on the street and pumping of cellar in Valkenburg, Dutch South Limbourg,
after an erosion event (Photo F. Kwaad).
Links to websites on
practical aspects of soil conservation in Europe
Keep in mind, that more may be going on
to combat erosion in Europe than is reflected on the Internet. Please,
report
any broken links. The site is regularly searched for broken links with
W3C
Link Checker.
Europe - General
National
Soil Degradation Maps (GLASOD)
Land
Use Policy, Volume 27, Issue 1, Pages 1-94 (January 2010) "Soil and Water
Conservation Measures in Europe"
European
Society for Soil Conservation (ESSC)
European
Conservation Agriculture Federation (ECAF)
International
Erosion Control Association (IECA)
European
Soil Portal
European
Soil Portal, updates
Soil
erosion risk in Europe
SCAPE
- Soil Conservation and Protection for Europe
SCAPE
- Proceedings of Iceland meeting, 2005
Pan-European
Soil Erosion Risk Assessment - PESERA Data
Pan-European
Soil Erosion Risk Assessment - PESERA Map
Nature
and extent of soil erosion in Europe
Soil
erosion in Europe (European Commission)
Soil
and water protection using conservation tillage in northern en central
Europe
Conservation
tillage in Europe - ISTRO
Policy
implementation for agricultural soil protection in the EU: an overview
of 24 member states
Historical
overview on soil protection policies in the European Union 1952-2006
Environmental
performance of agriculture in OECD countries since 1990
Down
to earth: Soil degradation and sustainable development in Europe (UNEP-EEA,
2000)
SoCo
- Sustainable agriculture and soil conservation (European Commission)
SoCo
- Welcome to the project and all project information (2007-2009)
SoCo
- project, kick-off meeting Brussels, October 2007
SoCo
- EU-wide stock-taking, current status, May 2008
SoCo
- Texts of workshop papers across Europe, 2008
SoCo
- Position of farmers on soil conservation practices in Europe
SoCo
- Final Report 2009 (report 172 pp.)
SoCo
- Addressing soil degradation in EU agriculture 2009 (report 332 pp.)
Different
outlooks of farmers and scientists on soil erosion and conservation (from
COST 634)
Incentives
in soil conservation
Situation
of conservation agriculture in Europe
Conservation
tillage and environment in Europe: reviewing the evidence
SOWAP
Impact of conservation tillage on soil erosion and runoff
Sustainability
and soil conservation
Impact
of soil legislation on farming in England and Spain
KASSA
project on conservation agriculture
History
of soil conservation USA
AMEWAM
project - Agricultural measures for water management and their integration
into spatial planning (Germany - Great Britain - The Netherlands)
Book
'Soil Erosion in Europe'
Soil conservation research using a rainfall
simulator on experimental plots in Wijnandsrade, South Limbourg, The Netherlands
(Photo F. Kwaad).
Multislot divisor for sampling runoff from an
experimental plot (Photo F. Kwaad).
Belgium
Bodemerosie
in België
Interreg-project
erosiebestrijding
Publicaties
Interreg-project erosiebestrijding (Eindrapport, Handboek, Acceptatie)
Interreg
bedrijfserosieplan
Wegwijzer
doorheen het erosiebesluit
Erosiebestrijding
MESAM
project
SOWAP
Images
of conservation work
Publicaties
erosiebestrijding
Voorbeelden
projecten erosiebestrijding
Infokrant
"Werk maken van erosiebestrijding"
Brochures
"Werk maken van erosiebestrijding"
Werk
maken van erosiebestrijding
Erosiebeperking
Oost-Vlaanderen
Folder
erosiebestrijding Oost-Vlaanderen
Erosiebestrijding
door niet-kerende grondbewerking
Bulgaria
Soil
erosion control in Bulgaria
Croatia
Soil
erosion under different tillage methods
Denmark
Tillage
systems
Deutschland - Germany
Bodenerosion
durch Wasser
Bodenerosion
Mecklenburg-Vorpommern
Bodenerosion
Baden-Württemberg
Bodenerosion
Bayern
Bodenerosion
Referate
Gesellschaft
für konservierende Bodenbearbeitung
Kassa
- Conservation agriculture in Germany
Profitability
of tillage methods - a field trial
Workshop
Direktsaat Leipzig
Direktsaat
Programm Niedersachsen
Eastern Europe
Additions are welcome.
England - UK
Soil
erosion in the UK
Soil
erosion in England and Wales
Soil
action plan for England
DEFRA
- Soil strategy for England
DEFRA
- Soil protection
DEFRA
- A code of good agricultural practice
DEFRA
- Controlling soil erosion in lowland England
DEFRA
- Preventing soil erosion in the uplands
Sustainable
practices to limit soil erosion
Direct
drilling (discussion on British Farming Forum)
No-till
wheat not for Western Europe (discussion among British farmers)
France
IFEN
- L'érosion des sols en France
INRA
- L'érosion des sols
Maitrise
du ruisellement agricole
Picardie
- lutte contre l'érosion
Haute
Normandie - protection des versants
Rhone-Alpes
- lutte contre l'érosion
Practical
soil protection in vineyards
Hungary
Direktsaat
Körnermais - Direct drilling of maize
Iceland
Soil
erosion
Soil
conservation
Soil
erosion in Iceland
Rofabards
in Iceland
Restoration
of degraded and desertified lands
Soil
conservation service Iceland
Soil
conservation in Iceland
Desertification
Desertification
2
RENO
- Restoration of damaged Ecosystems in the Nordic countries
Agricultural
Research Institute (RALA)
Italy
Soil
erosion risk in Italy, 2003
SoCo:
Agricoltura Sostenibile e Conservazione del Suolo, 2007
SoCo:
case study Marche region, 2007
Mediterranean region
Recondes
- Mitigation of desertification processes in Mediterranean Europe
Recondes
- Practical guidelines for minimal intervention
Conservation
scenarios for olive farming on sloping land in the Mediterranean
Additions for Spain, Portugal,
Italy and Greece are welcome. See below for Spain.
Moldova
Moldova
soil conservation project
Netherlands, The
Voorschriften
erosiebestrijding Zuid-Limburg vanaf 1 januari 2009
Subsidieregeling
niet-kerende grondbewerking Zuid-Limburg, ingaand 3 april 2008
Handboek
voor erosiebestrijding - Manual guidelines for erosion control (104 pp)
Niet-kerende
grondbewerking tegen erosie
Ploegloze
grondbewerking
Erosie
Zuid-Limburg (Productschap Akkerbouw)
LLTB
dossier erosiebestrijding
LNV
bodemerosie
Verordening
erosiebestrijding landbouwgronden
Verordening
erosiebestrijding tuinbouwgronden
Erosieverordening
met LISEM
Anti-erosieploeg
Roer
en Overmaas niet-kerende grondbewerking
Interreg-project
erosiebestrijding
Publicaties
Interreg-project erosiebestrijding (Eindrapport, Handboek, Acceptatie)
Oesterreich - Austria
Effectiveness
of soil erosion protection measures in Austrian agriculture
Scandinavian countries
Additions are welcome.
Schweiz - Switzerland
Swiss
no-till (Direktsaat)
Humusgehalte
nach 11 Jahren Direktsaat und Pflug
Direktsaat
und ihr Beitrag zum Bodenschutz
Bodenschutz
Nordwestschweiz
Forschungsprojekte
Erosion Agroscope ART
Bodenerosion
Solothurn
Bodenschutz
Kanton Basel
Bodenschutz
Kanton Bern
Southeastern Europe
Additions are welcome.
Spain - Espagne
Erosion:
la importancia de la conservacion del suelo
AEAC.SV
- Asociación Española Agricultura de Conservación
/ Suelos Vivos
Ministerio
- Medidas para la conservacion y proteccion del suelo
Buenas
condiciones agrarias
Conservación
y protección del suelo
Sustainable
olive growth in Andalucia (Olivar sostenible)
Furrows following the contours (From: Wat
een Wereld )
In recent years, conservation tillage, in
its various forms, has become increasingly popular as a means to combat
soil erosion. In 2005, 40.7% of all cropland in the USA was under some
form of conservation tillage (US
Tillage Trends). A global overview is given by Derpsch.
According to ECAF
agricultural conservation in Europe was very little developed in 1998 (estimated
at <1%-2% of its agricultural land). France and Spain are the
two countries in Europe where these techniques are practised the most,
with about 1 and 0.6 million hectares of annual crops under conservation
techniques in 1998. This is increasing. The following data for 2003 is
given by ECAF for the percentage of the agrarian surface under conservation
agriculture:
Belgium
10%
Ireland
4
Slovaqia
10
Switzerland
40
France
17
Germany
20
Portugal
1.3
Denmark
8
United Kingdom 30
Spain
14
Hungary
10
Italy
6
A special form of conservation tillage is subsurface tillage, i.e. non-inverting tillage with a type of plough that cuts a slice of soil loose from the subsoil without inverting it. As of 3 April 2008, farmers in Dutch South Limbourg can apply for a subsidy of 50 Euro per ha per year for adopting non-inverting soil tillage. Starting 2013, conventional ploughing will no longer be allowed in the region south of Sittard. Click hereto see the regulation.
Non inverting plough (From: Geelen
)
See also: Conservation tillage video
The effectiveness of conservation tillage
for erosion control is due to:
(a) Providing the soil surface with a protective
cover of growing crop and/or crop remains at all times; this prevents crust
formation by raindrop impact (so called surface sealing) taking place that
would lower the rate of infiltration of rain water below the rate at which
the rain falls.
(b) Conservation tillage helps forming and
maintaining a water stable soil structure. By conventional tillage a mechanical,
so called fragmentation structure is formed, the elements of which (clods)
are not stable in water. Under permanent vegetation a surface horizon is
formed with biogenic aggregates (peds) that are stable in water. A stable
soil structure is an important defence line against soil crusting.
Crust formation on bare soil. Aggregate
breakdown hinders infiltration of rainwater and causes surface runoff (overland
flow) on sloping fields (From: Chapter 6 in Sare
).
Infiltration excess overland flow occurs
when high intensity rain falls on a crusted or sealed soil. It can begin
immediately at the onset of rainfall, even on a dry soil. This form of
overland flow is called Horton or Hortonian overland flow. Controlling
variables are rainfall intensity and infiltration capacity of the soil,
both expressed in mm/h.
Another possible cause of overland flow
is the presence of an impeding layer at shallow depth in the soil. During
prolonged rainfall a perched groundwater table can form above the impeding
layer that may reach the soil surface. Lateral subsurface flow over the
impeding layer (throughflow, interflow) is involved in this, resurfacing
at some point downslope (return flow).
When and where the groundwater table is
already at the soil surface at the start of rainfall (such as can occur
along rivers and in lower parts of the landscape), overland flow can begin
immediately, irrespective of rainfall intensity.
The latter two forms of overland flow are
called saturated or saturation overland flow. Controlling variables are
rainfall amount and available storage capacity of the soil for water, both
expressed in mm.
A model of hydrologic processes on a hillslope (Source: University
of Colorado, Boulder )
Direct drilling in no-tilled soil (From: John
Dale Drills )
Direct drilling of maize in winterrye
as winter cover crop, Experimental Farm Wijnandsrade, The Netherlands (see
detail
of sowing machine) (Photos F. Kwaad).
No till corn after corn (From: Wendy
Kindig ). Click here for detail.
Strip tilled corn (From: Mitchell et al. )
