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

Name of project which facilitated the documentation/ evaluation of the Technology (if relevant)

OPtimal strategies to retAIN and re-use water and nutrients in small agricultural catchments across different soil-climatic regions in Europe (OPTAIN)

Name of the institution(s) which facilitated the documentation/ evaluation of the Technology (if relevant)

Helmholtz Centre for Environmental Research (UFZ) - Germany

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

2.1 Short description of the Technology

Definition of the Technology:

Riparian buffer strips refer to the permanent greening of arable land alongside streams and other water bodies. By slowing down runoff water from the land, they help to protect water bodies from diffuse pollution. Riparian buffer strips have multiple other environmental benefits, but disadvantages also.

2.2 Detailed description of the Technology

Description:

Riparian buffer strips comprise permanent, protective vegetation alongside streams and other water bodies. Our example represents a riparian buffer that evolved from set-aside land with naturally recovered vegetation. For the farmer, this has several advantages in terms of implementation, maintenance and seed costs. The farmer was able to simply leave the buffer strip open after ploughing without seeding or rolling, and maintenance requires only one mowing operation per year.
Riparian buffer strips are established at the edge of cultivated areas adjacent to water bodies. The width of the strip should be 5-15 m. In our example, the width of the buffer strip was 6 m, which was defined by working width of the mower. Depending on the type and width of the buffer, the rainfall intensity, the slope and the management, different filtering capacities can be attained by a buffer. An effective strip can retain 70% of the sediment and reduce nutrients in the surface runoff by 50%. However efficient retention of nutrients requires a buffer width of at least 15 m, while efficient retention of fine sediments requires a width of 15-20 m. The slope of the watercourse bank is also important: the optimum slope is 9-10%, and retention performance worsens with increasing slope (Kail et al. 2022).
Grass cover roughens the soil surface, slowing down the flow of water after heavy rainfall events and improving infiltration rates. Additionally, the roots of grasses increase infiltration, the plants absorb nitrate and prevent it from running off into the water bodies. Deeper roots, such as those from trees stabilize river banks, preventing bank erosion during heavy rainfall, as well as increasing shading of the stream. This improves the microclimate and creates better habitats for species native to the watercourse. Moreover, the buffer reduces the siltation of water bodies, preserves gravel bars, and thus preserves habitats. The buffer strip itself provides habitats for flora and fauna. The area adjacent to the buffer strip may experience increased dew formation and soil moisture, reduced evaporation, and wind protection.
The surface roughness of the grassed buffer strip depends on the type of vegetation. Cold-tolerant grasses such as perennial ryegrass (Lolium perenne) are commonly used, but a mix of grasses and trees is even better. Grassland provides an evenly distributed surface cover and the trees, with their deeper roots, provider higher infiltration capacity. Fast growing, low maintenance and regional species are optimal.
Proper maintenance is important for permanent erosion control. In case of nutrient-rich runoff from adjacent fields, the buffer strip may become saturated after a while and nitrification increases. Nitrous oxide is then produced which is a powerful greenhouse gases. In addition, the soil/vegetation is no longer able to absorb new nutrients, and they are washed into the water body. Mowing once per year removes biomass and can prevent nutrient saturation (Cole et al. 2020).
However, while promoting biodiversity and reducing soil erosion, buffer strips have a major downside for land-users and land-owners. They consume cropland, which leads to a decrease in production. The grass mixture can be used as fodder, but usually this does not compensate for the loss of production, which is why farmers often call for appropriate subsidies.

2.3 Photos of the Technology

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

2.6 Date of implementation

Indicate year of implementation:

2013

2.7 Introduction of the Technology

Specify how the Technology was introduced:

• through projects/ external interventions

Comments (type of project, etc.):

In order to meet the greening requirements of the CAP, 4% of the total agricultural area of a farm must be used, for example, for crop diversification, maintenance of permanent grassland or creation of ecological priority areas in order to receive direct payments from the state. In this case, a self-vegetated fallow was established as an ecological priority area to fulfill the greening requirements.

3.1 Main purpose(s) of the Technology

• reduce, prevent, restore land degradation
• conserve ecosystem
• protect a watershed/ downstream areas – in combination with other Technologies
• preserve/ improve biodiversity

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

Land use mixed within the same land unit:

No

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

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

• area closure (stop use, support restoration)
• improved ground/ vegetation cover
• cross-slope measure

3.6 SLM measures comprising the Technology

3.7 Main types of land degradation addressed by the Technology

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

4.1 Technical drawing of the Technology

4.2 General information regarding the calculation of inputs and costs

Specify how costs and inputs were calculated:

• per Technology area

other/ national currency (specify):

€

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

0.91

4.3 Establishment activities

Comments:

There are no establishment activities needed.

4.5 Maintenance/ recurrent activities

	Activity	Timing/ frequency
1.	Mowing	annually at the end of July

Comments:

The farmer in this case study mowed the grass and removed the biomass to prevent nutrient saturation in the riparian buffer. However, the amount of hay yield is small and not relevant according to the farmer.

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	mowing	ha	1.0	25.0	25.0
Total costs for maintenance of the Technology					25.0
Total costs for maintenance of the Technology in USD					27.47

If land user bore less than 100% of costs, indicate who covered the remaining costs:

121€/ha were covered by the state of Saxony as a subsidy (AL 5b- self-vegetated perennial needs on arable land; SMUL Sachsen, 2015).

4.7 Most important factors affecting the costs

Describe the most determinate factors affecting the costs:

A riparian buffer that developed from set-aside land with naturally recovered vegetation is not costly, as it requires only one mowing operation per year and nothing else. However, the buffer consumes agricultural land, leading to a reduction in agricultural production.

5.1 Climate

5.2 Topography

Indicate if the Technology is specifically applied in:

• not relevant

5.3 Soils

If available, attach full soil description or specify the available information, e.g. soil type, soil PH/ acidity, Cation Exchange Capacity, nitrogen, salinity etc.

Gleysol

5.4 Water availability and quality

Is water salinity a problem?

No

Is flooding of the area occurring?

No

5.5 Biodiversity

Comments and further specifications on biodiversity:

Normally, a self-vegetated fallow has a high species diversity (depending on the seeds present in the soil) and a medium habitat diversity. Unfortunately, the documented self-vegetated fallow is not properly maintained and the beneficial effects, e.g. species and habitat diversity, are correspondingly low.

5.6 Characteristics of land users applying the Technology

5.7 Average area of land used by land users applying the Technology

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

Land ownership:

• individual, not titled

Land use rights:

• leased
• individual

Water use rights:

• communal (organized)

Are land use rights based on a traditional legal system?

No

5.9 Access to services and infrastructure

6.1 On-site impacts the Technology has shown

Socio-economic impacts

Production

Income and costs

Ecological impacts

Water cycle/ runoff

Soil

Biodiversity: vegetation, animals

Climate and disaster risk reduction

Specify assessment of on-site impacts (measurements):

The assessment is based on the response of the interviewed farmer and not based on on-site measurements.

6.2 Off-site impacts the Technology has shown

Specify assessment of off-site impacts (measurements):

The assessment is based on the expertise of the compilers and not based on measurements in the case study.

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?
other gradual climate change	changing weather conditions	increase	well

6.4 Cost-benefit analysis

How do the benefits compare with the maintenance/ recurrent costs (from land users' perspective)?

Comments:

No establishment costs. Comment by the farmer: "There is no benefit at all".

6.5 Adoption of the Technology

• 1-10%

Of all those who have adopted the Technology, how many did so spontaneously, i.e. without receiving any material incentives/ payments?

• 0-10%

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 compiler’s or other key resource person’s view
Increased infiltration rates
Reduced erosion and nutrient runoff into watercourse
Deeper roots, such as those of trees, stabilize river banks against break-off during heavy rainfall.
Trees increase shading and microclimate for stream species.

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 in yield due to loss of arable land.	Accordingly, the yield loss should be offset by subsidies. Use grass mixture as fodder.

7.1 Methods/ sources of information

7.2 References to available publications

Title, author, year, ISBN:

Kail et al. (2022): Ökologische Funktionen von Gewässerrandstreifen. LfULG Broschüre

Available from where? Costs?

https://publikationen.sachsen.de/bdb/artikel/40152

7.3 Links to relevant online information

Title/ description:

Cole et al. (2020): Managing riparian buffer strips to optimise ecosystem services: A review. Agriculture, Ecosystems & Environment 296

URL:

https://doi.org/10.1016/j.agee.2020.106891

Title/ description:

SMUL Sachsen (2015): Förderperiode 2014-2020 - Art. 28 der Verordnung (EU) Nr. 1305/2013 - Richtlinie Agrarumwelt- und Klimamaßnahmen (RL AUK/2015) - Sächsisches Agrarumwelt- und Naturschutzprogramm (AUNaP)

URL:

https://www.smul.sachsen.de/lfulg/download/AUK-Massnahmen-Ueberblick.pdf

Title/ description:

Hebblethwaite & Somody (2008): Progress in Best Management Practices. In: The Triazine Herbicides. 50 years Revolutionizing Agriculture

URL:

https://doi.org/10.1016/B978-044451167-6.50035-0