Technologies

Grass buffer zones alongside waterways in cropland [Norway]

Grasdekt buffersone

technologies_1656 - Norway

Completeness: 94%

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:
SLM specialist:
Name of project which facilitated the documentation/ evaluation of the Technology (if relevant)
Preventing and Remediating degradation of soils in Europe through Land Care (EU-RECARE )
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

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

Yes

1.4 Declaration on sustainability of the described Technology

Is the Technology described here problematic with regard to land degradation, so that it cannot be declared a sustainable land management technology?

No

1.5 Reference to Questionnaire(s) on SLM Approaches (documented using WOCAT)

2. Description of the SLM Technology

2.1 Short description of the Technology

Definition of the Technology:

Grass buffer zones are established along waterways in cropland to reduce the surface runoff rate, and the amounts of sediment, nutrients and pesticides in the runoff.

2.2 Detailed description of the Technology

Description:

Commonly used names: buffer zones, buffer strips, riparian buffers

Purpose/aim: Vegetative buffers are areas of permanent vegetation located within and between agricultural fields and the watercourses to which they drain. The purpose of the vegetative buffer is to intercept, and reduce the rates of surface runoff and to reduce loads of sediment, nutrients and pesticide delivered to waterways. The processes involved are filtration, sedimentation, infiltration and absorption. Reducing the input of particles and nutrients into surface waterways is desirable both to improve water quality and to prevent eutrophication of downstream water bodies. In Norway, buffer zones are primarily established to reduce surface runoff of particles and phosphorus. However, vegetation in these zones can also serve other useful functions, such as protection against bank erosion, production of biomass, and/or provision of habitats for wildlife.

Establishment/maintenance activities:
Buffer zones are most commonly designed to retain inputs of nutrients and particles from adjacent fields. Vegetative buffers may be constructed or naturally vegetated, within or alongside fields, or adjacent to drainage ditches, streams, lakes, ponds, and wetlands. The buffer zones may consist of grass for fodder production, or be natural vegetation composed of herbs, weeds, bushes and trees.

In Norway, farmers receive subsidies when the area is still used for production, e.g. grass production for fodder. Farmers leave a strip in cropland for grass and herbs to grow alongside rivers, streams and lakes that intersect their cropland areas. It is recommended to sow grass when establishing grass buffer zones. Robust and dense grass types with a high uptake of nutrients are often the best suited for the purpose. The grass strips should generally not be ploughed, fertilized or treated by herbicides, but some exceptions may be made. The degree to which the grass is harvested varies with the grass type and if it is valuable for livestock fodder.

Buffer zones are one of the most common measures in Norway, and the requirements for the dimension of buffer zones have changed with time - and depend on the region. According to current regulations, buffer zones between the field and the watercourse have to be a minimum of 2 meters in order to qualify for production subsidies (PT-forskriften, § 4). In addition, there is a national recommendation (RMP) to maintain a minimum 6-metre wide buffer zone along all watercourses. However, regional guidelines (RMP) can differ from national ones and the width recommendation differ from county to county.


Benefits/impact: The effectiveness of buffer zones in retaining nutrients and soil particles has been explored by many authors. Retention capacity for phosphorus in buffer zones depends on several factors including vegetation, soil type, slope, hydrological conditions, and the width of the zone. There are large variations in the effectiveness of buffer zones: 32-91% retention of sediment, 26-100% retention of phosphorus and 0-100% retention of nitrogen. The retention effect of grass buffer zones along the Hobøl River, measured with rainfall simulation experiments under the BUFFERKLIMA project (Krzeminska et al., 2020), was: 86-94% for sediment, 86-86% for phosphorus and 78-89% for nitrogen.

Natural / human environment: The information about this Technology is based on investigations and/or reports from different part of Norway. For the purpose of the OPTAIN project, the technology is further presented in the natural and human environment context of the Kråkstad River catchment - a Norwegian Case Study catchment within the project.

The Kråkstad River is mainly situated in the Ski municipality in the South-Eastern part of Norway. The river catchment is a western tributary of the Vansjø-Hobøl watercourse, also known as the Morsa watercourse. The Kråkstad River catchment area is c. 51 km², 43% of which is agricultural land. Cereals are the major crop, produced on the heavy clays soils. The main environmental challenge in the area is water quality (incl. high phosphorus pollution) and soil erosion (incl. riverbank erosion and quick-clay landslides).The Morsa watercourse is a drinking water resource and there are specific environmental regulations for land management supported by subsidies through the Regional Environmental Programme (RMP).

2.3 Photos of the Technology

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

Country:

Norway

Region/ State/ Province:

Viken county

Further specification of location:

The Vansjø - Hobøl catchment

Specify the spread of the Technology:
  • evenly spread over an area
If precise area is not known, indicate approximate area covered:
  • 1-10 km2
Is/are the technology site(s) located in a permanently protected area?

No

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
  • through projects/ external interventions
  • Regional Environmental Programme (RMP)
Comments (type of project, etc.):

The Morsa Project (morsa.org)

Buffer zones along streams and lakes are measures eligible for subsidies under the Regional Environmental Programme (RMP).

3. Classification of the SLM Technology

3.1 Main purpose(s) of the Technology

  • reduce, prevent, restore land degradation
  • protect a watershed/ downstream areas – in combination with other Technologies

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

Cropland

Cropland

  • Annual cropping
Annual cropping - Specify crops:
  • cereals - other
  • small grains
Number of growing seasons per year:
  • 1
Specify:

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

Forest/ woodlands

Forest/ woodlands

Products and services:
  • Fuelwood
Comments:

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 Has land use changed due to the implementation of the Technology?

Has land use changed due to the implementation of the Technology?
  • Yes (Please fill out the questions below with regard to the land use before implementation of the Technology)
Land use mixed within the same land unit:

No

Cropland

Cropland

  • Annual cropping
Annual cropping - Specify crops:
  • fodder crops - grasses
Comments:

When buffer zones are implemented, part of the cropland is occupied by the grass strips. The grass strips should generally not be ploughed, fertilized or treated by herbicides, but some exceptions may be made. The degree to which it is harvested varies with the grass type, and if it is used for animal fodder.

3.4 Water supply

Water supply for the land on which the Technology is applied:
  • rainfed

3.5 SLM group to which the Technology belongs

  • surface water management (spring, river, lakes, sea)

3.6 SLM measures comprising the Technology

vegetative measures

vegetative measures

  • V2: Grasses and perennial herbaceous plants

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
Comments:

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,
Wr: riverbank erosion
Wm: mass movements/landslides,


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
Comments:

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

Technical specifications (related to technical drawing):

A technical drawing of a grass buffer zone - example setup based on the Norwegian recomendation

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

Trees/ shrubs species: Naturally
Grass species: Seeded

Author:

Kamilla Skaalsveen

4.2 General information regarding the calculation of inputs and costs

Specify how costs and inputs were calculated:
  • per Technology unit
Specify unit:

a buffer zone strip along the stream or lake

Specify dimensions of unit (if relevant):

dimensions can vary greatly

other/ national currency (specify):

Kroner (NOK)

If relevant, indicate exchange rate from USD to local currency (e.g. 1 USD = 79.9 Brazilian Real): 1 USD =:

8.89

Indicate average wage cost of hired labour per day:

c.a. 3000 NOK (it is only the cost of the time assuming 8h work per day, 320-500 NOK/hour; person; machinery, equipment, materials not included)

4.3 Establishment activities

Activity Timing (season)
1. Plowing 1 time/yr
2. Harrowing 2-3 times/yr
3. Sowing grass 2-3 times/yr
4. Harvesting grass 2-3 times/yr

4.4 Costs and inputs needed for establishment

Specify input Unit Quantity Costs per Unit Total costs per input % of costs borne by land users
Labour Ploughing 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 Sowing 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
Total costs for establishment of the Technology in USD 144.43
If land user bore less than 100% of costs, indicate who covered the remaining costs:

Grass covered buffer zones are measures eligible for subsidies under the Regional Environmental Programme (RMP)

Comments:

The costs of establishment and management of grass covered buffer zone are the same as in the case of regular crop land management. The subsidy is compensation for land withdrawn from the main production (crop land).
Grass covered buffer zones are measures eligible for subsidies under Regional Environmental Programme (RMP) - between 2019 and 2022 the subsidy for grass covered buffer zones was 15 kr/m in Viken county.

4.5 Maintenance/ recurrent activities

Activity Timing/ frequency
1. Ploughing Every 5th year
2. Harrowing Every 5th year
3. Sowing grass Every 5th year
4. Harvesting grass 1-2 times/yr
Comments:

These areas are often used as grass production areas so some maintenance and harvesting of grass is needed.

4.6 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 Ploughing zone/farmer/day 1.0 53.0 53.0
Labour Harrowing zone/farmer/day 1.0 321.0 321.0
Labour Sowing 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
Total costs for maintenance of the Technology in USD 114.29
If land user bore less than 100% of costs, indicate who covered the remaining costs:

Grass covered buffer zones are eligible for subsidies under the Regional Environmental Programme (RMP)

Comments:

The costs of establishment and management of grass covered buffer zones are are the same as in case of regular crop land management.

Maintenance of grassed buffer zones is a part of the subsidy system:
-production subsidies - the regulations relating to production subsidies include a number of environmental standards that farmers must meet to receive production support, including two-metre buffer zones along water ways. A farmer who does not comply with the requirements may lose part of their production subsidies.
- RMP - Buffer zones may be eligible for subsidies under the Regional Environmental Programme (RMP) – for 2019-2022 the subsidy level for maintaining grass covered buffer zones was 15 kr/m in the Viken region. The subsidy is compensation for land withdrawn from the main production (crop land).

4.7 Most important factors affecting the costs

Describe the most determinate factors affecting the costs:

The costs of establishment and management of grass buffer zone are are the same as in case of regular crop land management. The subsidy is compensation for land withdrawn from the main production (crop land).

Establishment and maintenance costs of buffer strip depends mostly on:
- the area (width and continuity) of the buffer strip.
- type of vegetation
- possibility to use the grass as a fodder.

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%)
Landforms:
  • 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):
  • medium (loamy, silty)
  • fine/ heavy (clay)
Soil texture (> 20 cm below surface):
  • medium (loamy, silty)
  • 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:

good

Water quality (untreated):

for agricultural use only (irrigation)

Water quality refers to:

both ground and surface water

Is water salinity a problem?

No

Is flooding of the area occurring?

Yes

Regularity:

frequently

5.5 Biodiversity

Species diversity:
  • low
Habitat diversity:
  • low

5.6 Characteristics of land users applying the Technology

Sedentary or nomadic:
  • Sedentary
Market orientation of production system:
  • mixed (subsistence/ commercial)
  • commercial/ market
Off-farm income:
  • 10-50% of all income
  • > 50% of all income
Relative level of wealth:
  • average
  • rich
Individuals or groups:
  • individual/ household
Level of mechanization:
  • mechanized/ motorized
Gender:
  • women
  • men
Age of land users:
  • youth
  • middle-aged
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 used 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

health:
  • poor
  • moderate
  • good
education:
  • poor
  • moderate
  • good
technical assistance:
  • poor
  • moderate
  • good
employment (e.g. off-farm):
  • poor
  • moderate
  • good
markets:
  • poor
  • moderate
  • good
energy:
  • 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

Production

crop production

decreased
increased

production area

decreased
increased
Comments/ specify:

The grass (from buffer strips) is often unfit for fodder

Income and costs

farm income

decreased
increased
Comments/ specify:

Despite subsidies, many farmers view grass buffer zones as a financial loss since the grass is often unfit for fodder.

diversity of income sources

decreased
increased

workload

increased
decreased

Socio-cultural impacts

Improved livelihoods and human well-being

decreased
increased
Comments/ specify:

Because of the drinking water quality

Ecological impacts

Water cycle/ runoff

water quality

decreased
increased
Comments/ specify:

less sediment and nutrient input to surface water

Soil

soil cover

reduced
improved

soil loss

increased
decreased

soil compaction

increased
reduced

nutrient cycling/ recharge

decreased
increased
Biodiversity: vegetation, animals

plant diversity

decreased
increased

beneficial species

decreased
increased

habitat diversity

decreased
increased

6.2 Off-site impacts the Technology has shown

groundwater/ river pollution

increased
reduced

buffering/ filtering capacity

reduced
improved

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 increase or decrease How does the Technology cope with it?
annual temperature increase well
annual rainfall increase well

Climate-related extremes (disasters)

Meteorological disasters
How does the Technology cope with it?
local rainstorm moderately
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 moderately

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

  • 11-50%
Of all those who have adopted the Technology, how many did so spontaneously, i.e. without receiving any material incentives/ payments?
  • 0-10%
Comments:

There is no trend towards spontaneous adoption of the Technology. Doubts about the retention capacity of buffer zones reduce farmers’ motivation.
Local regulations determine that farmers only receive subsidies per production area along with financial grants if they implement the technology.

6.6 Adaptation

Has the Technology been modified recently to adapt to changing conditions?

No

6.7 Strengths/ advantages/ opportunities of the Technology

Strengths/ advantages/ opportunities in the land user’s view
Probably good for the environment
Strengths/ advantages/ opportunities in the compiler’s or other key resource person’s view
The grass captures sediments and nutrients from the cropland

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

How can they be sustained / enhanced? Continue in the same way
Co-operation between farmers

How can they be sustained / enhanced? Joint utilization of 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
Not always good for the farm economy Review the subsidies scheme
Doubts about the effectiveness of the technology (infiltration and stream bank erosion)
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

7. References and links

7.1 Methods/ sources of information

  • field visits, field surveys

BUFFERKLIMA project (Krzeminska et al 2020)
Projects within Halden, MORSA and PURA water region (Blankenberg and Skarbøvik, 2020)

  • compilation from reports and other existing documentation
When were the data compiled (in the field)?

10/02/2022

7.2 References to available publications

Title, author, year, ISBN:

Blankenberg, A-G.B., Skarbøvik E., 2020. Phosphorus retention, erosion protection and farmers’ perceptions of riparian buffer zones with grass and natural vegetation: Case studies from South-Eastern Norway.

Available from where? Costs?

Ambio

Title, author, year, ISBN:

Krzeminska D, Blankenberg A‐G, Bøe F, Nemes A, Skarbøvik E. 2020.Renseeffekt og kanterosjon i kantsoner med forskjellig vegetasjonstype.

Available from where? Costs?

NIBIO website

Title, author, year, ISBN:

Blankenberg, A-G.B., Skarbøvik E., Kværnø S. 2017. Effekt av buffersoner ‐ på vannmiljø og andre økosystemtjenester.

Available from where? Costs?

NIBIO website

7.3 Links to relevant online information

Title/ description:

Blankenberg and Skarbøvik, 2020. Phosphorus retention, erosion protection and farmers’ perceptions of riparian buffer zones with grass and natural vegetation: Case studies from South-Eastern Norway.

URL:

https://link.springer.com/content/pdf/10.1007/s13280-020-01361-5.pdf

Title/ description:

Krzeminska D, Blankenberg A‐G, Bøe F, Nemes A, Skarbøvik E. 2020.Renseeffekt og kanterosjon i kantsoner med forskjellig vegetasjonstype.

URL:

https://nibio.brage.unit.no/nibio-xmlui/bitstream/handle/11250/2645890/NIBIO_RAPPORT_2020_6_30.pdf?sequence=2&isAllowed=y

Title/ description:

Blankenberg, A-G.B., Skarbøvik E., Kværnø S. 2017. Effekt av buffersoner ‐ på vannmiljø og andre økosystemtjenester.

URL:

https://nibio.brage.unit.no/nibio-xmlui/bitstream/handle/11250/2448787/NIBIO_RAPPORT_2017_3_14.pdf?sequence=2&isAllowed=y

7.4 General comments

no remarks

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