This is an outdated, inactive version of this case. Go to the current version.

Grass Covered Riparian Buffer Strips [Norway]

Grasdekt buffersone

technologies_1656 - Norway

Completeness: 76%

1. General information

1.2 Contact details of resource persons and institutions involved in the assessment and documentation of the Technology

Key resource person(s)

SLM specialist:
Name of the institution(s) which facilitated the documentation/ evaluation of the Technology (if relevant)
Norwegian Institute for Agricultural and Environme (Norwegian Institute for Agricultural and Environme) - Norway

1.3 Conditions regarding the use of data documented through WOCAT

When were the data compiled (in the field)?


The compiler and key resource person(s) accept the conditions regarding the use of data documented through WOCAT:


2. Description of the SLM Technology

2.1 Short description of the Technology

Definition of the Technology:

Establishment of grass covered vegetation strips along cropland waterways for reduced erosion and infiltration of surface runoff.

2.2 Detailed description of the Technology


The farmers leave a strip of cropland for grass and herbs to grow along rivers, streams and lakes that intersect their cropland areas. Regulations that origins from the Morsa project ( require vegetation zones with a width of approximately eight meters. The establishment of these buffer zones is of high importance in areas regularly exposed to flooding.

Purpose of the Technology: The buffer strips are a measure to slow down surface runoff for more water to infiltrate and for particles carried by the water to settle in the vegetation. It is also meant to contribute to reduce erosion and increase the binding of phosphorous to soil particles, as well as the uptake by the vegetation. A decreased input of particles and nutrients to the cropland waterways is desirable both in order to limit soil loss and to prevent eutrophication of downstream waterbodies.

Establishment / maintenance activities and inputs: To sow grass is recommended when establishing grass covered riparian buffer strips. Robust and dense grass types with a high demand of nutrients are often the most suited for the purpose. The grass strips should generally not be plowed, fertilized or treated by herbicides, but some exceptions may be made. The degree of which it is harvested varies with the grass type and if it is used for animal fodder.

Natural / human environment: The Kråkstad River is mainly situated in Ski commune in Akershus County in South-Eastern parts of Norway. The river catchment is a western tributary of the Vannsjø-Hobøl watercourse, also known as the Morsa watercourse. The Kråkstad River catchment constitutes of a total area of about 22 km², consisting mainly of cropland and forest/woodland. The recipient Vannsjø is a eutrophic lake with a history of algal blooms of e.g. toxic cyanobacterias. The lake is both used as a drinking water source and for recreational purposes, and the Morsa project was established in order to find measures to improve the water quality of Vannsjø.

2.3 Photos of the Technology

2.5 Country/ region/ locations where the Technology has been applied and which are covered by this assessment



Region/ State/ Province:


Further specification of location:



Boundary points of the Technology area: (59.595, 10.896), (59.611, 10.866), (59.670, 10.869), (59.676, 10.849), (59.717, 10.844), (59.723, 10.893), (59.694, 10.969), (59.655, 10.952), (59.668, 10.904), (59.629, 10.915)

2.6 Date of implementation

If precise year is not known, indicate approximate date:
  • 10-50 years ago

2.7 Introduction of the Technology

Specify how the Technology was introduced:
  • during experiments/ research
Comments (type of project, etc.):

The Morsa Project (

3. Classification of the SLM Technology

3.2 Current land use type(s) where the Technology is applied



  • Annual cropping
Main crops (cash and food crops):

Major cash crop annual cropping: Small grain
Major cash crop tree/shrub cropping: Fire wood

Forest/ woodlands

Forest/ woodlands

Products and services:
  • Fuelwood

Major land use problems (compiler’s opinion): Erosion, flooding and landslides, eutrophication of rivers and lakes.

Major land use problems (land users’ perception): Cropland is occupied by the buffer strips, which may lead to decreased production and loss of income.

3.3 Further information about land use

Water supply for the land on which the Technology is applied:
  • rainfed
Number of growing seasons per year:
  • 1

Longest growing period in days: 135Longest growing period from month to month: May to mid September

3.4 SLM group to which the Technology belongs

  • cross-slope measure
  • surface water management (spring, river, lakes, sea)

3.5 Spread of the Technology


Total area covered by the SLM Technology is 4.3 m2.

3.6 SLM measures comprising the Technology

vegetative measures

vegetative measures

  • V2: Grasses and perennial herbaceous plants

Main measures: vegetative measures

3.7 Main types of land degradation addressed by the Technology

soil erosion by water

soil erosion by water

  • Wt: loss of topsoil/ surface erosion
  • Wg: gully erosion/ gullying
  • Wm: mass movements/ landslides
  • Wr: riverbank erosion
water degradation

water degradation

  • Hp: decline of surface water quality

Main type of degradation addressed: Wt: loss of topsoil / surface erosion, Hp: decline of surface water quality

Secondary types of degradation addressed: Wg: gully erosion / gullying, Wm: mass movements / landslides, Wr: riverbank erosion

Main causes of degradation: soil management (Use of fertilizer and heavy machinery (compression of the soil and low infiltration rate)), crop management (annual, perennial, tree/shrub), Heavy / extreme rainfall (intensity/amounts) (More flooding and erosion), floods

Secondary causes of degradation: deforestation / removal of natural vegetation (incl. forest fires) (The runoff has a lower retention time in the forest. Leads to higher velocity and more flooding of downstream cropland areas), change of seasonal rainfall (Heavier rainfall events due to climate change), land tenure, governance / institutional

3.8 Prevention, reduction, or restoration of land degradation

Specify the goal of the Technology with regard to land degradation:
  • prevent land degradation
  • reduce land degradation

Main goals: mitigation / reduction of land degradation

Secondary goals: prevention of land degradation

4. Technical specifications, implementation activities, inputs, and costs

4.1 Technical drawing of the Technology


Kamilla Skaalsveen

4.2 Technical specifications/ explanations of technical drawing

A technical drawing of a grass covered riperian buffer strip with grass cover and riperian vegetation

Technical knowledge required for field staff / advisors: low

Technical knowledge required for land users: low

Main technical functions: control of concentrated runoff: impede / retard

Secondary technical functions: control of raindrop splash, control of dispersed runoff: retain / trap, control of dispersed runoff: impede / retard, control of concentrated runoff: retain / trap, improvement of ground cover, increase of surface roughness, increase of infiltration, increase / maintain water stored in soil, improvement of water quality, buffering / filtering water, sediment retention / trapping, sediment harvesting

Aligned: -along boundary
Vegetative material: T : trees / shrubs

Vegetative measure: Along waterways
Vegetative material: G : grass

Vegetative measure: Vegetative material: G : grass

Vegetative measure: Vegetative material: G : grass

Vegetative measure: Vegetative material: G : grass

Trees/ shrubs species: Naturally

Grass species: Seeded

4.3 General information regarding the calculation of inputs and costs

other/ national currency (specify):

Kroner (NOK)

Indicate exchange rate from USD to local currency (if relevant): 1 USD =:


Indicate average wage cost of hired labour per day:


4.4 Establishment activities

Activity Type of measure Timing
1. Plowing Vegetative 1 time/yr
2. Harrowing Vegetative 2-3 times/yr
3. Sawing grass Vegetative 2-3 times/yr
4. Harvesting grass Vegetative 2-3 times/yr

4.5 Costs and inputs needed for establishment

Specify input Unit Quantity Costs per Unit Total costs per input % of costs borne by land users
Labour Plowing zone/farmer/day 1.0 321.0 321.0 7.0
Labour Harrowing zone/farmer/day 1.0 321.0 321.0 7.0
Labour Sawing grass zone/farmer/day 1.0 321.0 321.0 7.0
Labour Harvesting grass zone/farmer/day 1.0 321.0 321.0 7.0
Total costs for establishment of the Technology 1284.0

4.6 Maintenance/ recurrent activities

Activity Type of measure Timing/ frequency
1. Plowing Vegetative Once every 6th year
2. Harrowing Vegetative 2-3 times/yr
3. Sawing grass Vegetative 2-3 times/yr
4. Harvesting grass Vegetative 2-3 times/yr

4.7 Costs and inputs needed for maintenance/ recurrent activities (per year)

Specify input Unit Quantity Costs per Unit Total costs per input % of costs borne by land users
Labour Plowing zone/farmer/day 1.0 53.0 53.0 100.0
Labour Harrowing zone/farmer/day 1.0 321.0 321.0
Labour Sawing grass Day 1.0 321.0 321.0
Labour Harvesting grass Day 1.0 321.0 321.0
Total costs for maintenance of the Technology 1016.0

5. Natural and human environment

5.1 Climate

Annual rainfall
  • < 250 mm
  • 251-500 mm
  • 501-750 mm
  • 751-1,000 mm
  • 1,001-1,500 mm
  • 1,501-2,000 mm
  • 2,001-3,000 mm
  • 3,001-4,000 mm
  • > 4,000 mm
Agro-climatic zone
  • sub-humid
  • semi-arid

Thermal climate class: temperate

Thermal climate class: boreal

5.2 Topography

Slopes on average:
  • flat (0-2%)
  • gentle (3-5%)
  • moderate (6-10%)
  • rolling (11-15%)
  • hilly (16-30%)
  • steep (31-60%)
  • very steep (>60%)
  • plateau/plains
  • ridges
  • mountain slopes
  • hill slopes
  • footslopes
  • valley floors
Altitudinal zone:
  • 0-100 m a.s.l.
  • 101-500 m a.s.l.
  • 501-1,000 m a.s.l.
  • 1,001-1,500 m a.s.l.
  • 1,501-2,000 m a.s.l.
  • 2,001-2,500 m a.s.l.
  • 2,501-3,000 m a.s.l.
  • 3,001-4,000 m a.s.l.
  • > 4,000 m a.s.l.

5.3 Soils

Soil depth on average:
  • very shallow (0-20 cm)
  • shallow (21-50 cm)
  • moderately deep (51-80 cm)
  • deep (81-120 cm)
  • very deep (> 120 cm)
Soil texture (topsoil):
  • fine/ heavy (clay)
Topsoil organic matter:
  • medium (1-3%)
If available, attach full soil description or specify the available information, e.g. soil type, soil PH/ acidity, Cation Exchange Capacity, nitrogen, salinity etc.

Soil fertility is medium-high
Soil drainage/infiltration is poor
Soil water storage capacity is very low-low

5.4 Water availability and quality

Ground water table:

< 5 m

Availability of surface water:


Water quality (untreated):

for agricultural use only (irrigation)

5.5 Biodiversity

Species diversity:
  • low

5.6 Characteristics of land users applying the Technology

Market orientation of production system:
  • mixed (subsistence/ commercial
  • commercial/ market
Off-farm income:
  • > 50% of all income
Relative level of wealth:
  • average
  • rich
Individuals or groups:
  • individual/ household
Level of mechanization:
  • mechanized/ motorized
  • women
  • men
Indicate other relevant characteristics of the land users:

Land users applying the Technology are mainly common / average land users
Population density: < 10 persons/km2
Annual population growth: < 0.5%
10% of the land users are rich and own 10% of the land.
90% of the land users are average wealthy and own 90% of the land.

5.7 Average area of land owned or leased by land users applying the Technology

  • < 0.5 ha
  • 0.5-1 ha
  • 1-2 ha
  • 2-5 ha
  • 5-15 ha
  • 15-50 ha
  • 50-100 ha
  • 100-500 ha
  • 500-1,000 ha
  • 1,000-10,000 ha
  • > 10,000 ha
Is this considered small-, medium- or large-scale (referring to local context)?
  • medium-scale

5.8 Land ownership, land use rights, and water use rights

Land ownership:
  • individual, titled
Land use rights:
  • communal (organized)
  • individual
Water use rights:
  • open access (unorganized)

5.9 Access to services and infrastructure

  • poor
  • moderate
  • good
  • poor
  • moderate
  • good
technical assistance:
  • poor
  • moderate
  • good
employment (e.g. off-farm):
  • poor
  • moderate
  • good
  • poor
  • moderate
  • good
  • poor
  • moderate
  • good
roads and transport:
  • poor
  • moderate
  • good
drinking water and sanitation:
  • poor
  • moderate
  • good
financial services:
  • poor
  • moderate
  • good

6. Impacts and concluding statements

6.1 On-site impacts the Technology has shown

Socio-economic impacts


crop production


risk of production failure


production area

Income and costs

expenses on agricultural inputs


farm income


diversity of income sources




Socio-cultural impacts

Improved livelihoods and human well-being

Comments/ specify:

Because of the drinking water quality

Ecological impacts

Water cycle/ runoff

water quality


soil cover


soil loss


soil crusting/ sealing


soil compaction


nutrient cycling/ recharge

Biodiversity: vegetation, animals

biomass/ above ground C


plant diversity


beneficial species


habitat diversity


6.2 Off-site impacts the Technology has shown

groundwater/ river pollution


buffering/ filtering capacity


6.3 Exposure and sensitivity of the Technology to gradual climate change and climate-related extremes/ disasters (as perceived by land users)

Gradual climate change

Gradual climate change
Season Type of climatic change/ extreme How does the Technology cope with it?
annual temperature increase well

Climate-related extremes (disasters)

Meteorological disasters
How does the Technology cope with it?
local rainstorm not well
local windstorm well
Climatological disasters
How does the Technology cope with it?
drought well
Hydrological disasters
How does the Technology cope with it?
general (river) flood not well

Other climate-related consequences

Other climate-related consequences
How does the Technology cope with it?
reduced growing period well

6.4 Cost-benefit analysis

How do the benefits compare with the establishment costs (from land users’ perspective)?
Short-term returns:

slightly negative

Long-term returns:

neutral/ balanced

How do the benefits compare with the maintenance/ recurrent costs (from land users' perspective)?
Short-term returns:

slightly negative

Long-term returns:

slightly negative

6.5 Adoption of the Technology


Comments on acceptance with external material support: Local regulations determine that farmers only receive subsidies per production area along with financial grants if they implement the technology.

There is no trend towards spontaneous adoption of the Technology

6.7 Strengths/ advantages/ opportunities of the Technology

Strengths/ advantages/ opportunities in the compiler’s or other key resource person’s view
The grass catches sediments from the cropland

How can they be sustained / enhanced? May be more efficient with a change in grass type (but this is not tested)
Reduced fertilizer usage

How can they be sustained / enhanced? Continue in the same way
Corporation between farmers

How can they be sustained / enhanced? Joint company for utilizing the buffer strips for grass production

6.8 Weaknesses/ disadvantages/ risks of the Technology and ways of overcoming them

Weaknesses/ disadvantages/ risks in the land user’s view How can they be overcome?
Loss of productive cropland Narrower buffer strips
Weaknesses/ disadvantages/ risks in the compiler’s or other key resource person’s view How can they be overcome?
Low infiltration rates Less heavy machinery on the buffer strips and a wider zone of natural vegetation along the banks

Links and modules

Expand all Collapse all