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)

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

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

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

Comments:

The technology has shown positive result (increased production) where it has been implemented. No adverse impacts have been reported.

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

Promotion of different trees for agroforestry [Kenya]

Promoting the values of different trees and their benefits in agroforestry contributes to increased adoption by farmers.

• Compiler: William Akwanyi
• 03/20/2023 10:04 a.m.

2.1 Short description of the Technology

Definition of the Technology:

Cross-slope barriers in the form of vegetative strips are established on sloping lands to reduce runoff velocity and prevent soil loss, thereby contributing to the conservation of soil, water, and plant nutrients.

2.2 Detailed description of the Technology

Description:

Vegetative cross-slope barriers are strips of perennial plants that are established along the contours of sloping lands. They act as soil and water conservation measures to reduce runoff velocity and consequently prevent soil loss. The strips are mostly between 0.3 m and 1.5 m wide and consist initially of one or two rows of plants. They slow down the speed of runoff during heavy rainfall. This facilitates infiltration, and eroded sediment in the runoff is trapped on the upslope side of the barriers. Hence, they contribute to the conservation of soil, water, and plant nutrients. The most used plants/ crops used in establishing vegetative cross-slope barriers are perennial erect grasses, including Brachiaria sp., napier grass (Pennisetum purpureum), and vetiver grass (Vetiver zizanioides). Depending on species (vetiver being an exception), vegetative cross-slope barriers can serve as important sources of fodder for livestock. Some farmers prefer to establish crops (e.g., bananas and pineapples) or trees and shrubs (e.g., (e.g., Calliandra calothyrus, Grevillea robusta or Sesbania sesban) as cross-slope barriers at appropriate spacing (depending on the tree/ shrub) to serve as windbreakers as well as providing additional measures to control soil erosion. Alternatively, these may be combined with grasses. These can also serve as important sources of food, fodder, fuel, and timber.

In establishing vegetative cross-slope barriers, the distance between the barriers is dictated by the slope of the land. The ProSoil project through Welthungerhilfe trained Community Resource Persons (CRPs) on how to survey contours using a line level. The CRPs by extension train farmers on how to measure slope for their fields and how to determine the distance between the barriers using a predetermined scale. Once established, minimal labour is required for maintenance. The main vegetation (grasses) must be harvested or cut back to a height of less than 0.5 m before planting a crop in the main field to prevent them from suppressing the crops through shading. The trees, and shrubs may need to be trimmed (coppiced) during the cropping period to allow adequate sunlight to reach the crops. The cut material can be collected and used as fodder or firewood as appropriate or be incorporated during land preparation, or during weeding as mulch.

Farmers like the technology because it contributes to soil, water, and nutrient conservation and it reduces the steepness of the slope as soil eroded from the upper part of the slope accumulates on the upslope side of the barrier resulting, eventually, in distinct terrace-like benches. As a result, farmers find it easier to cultivate on these terraces. Vegetative cross-slope barriers can be associated with retention ditches, especially where farmers find it important to harvest the water. They can also provide firewood and fodder, especially where palatable cut and carry varieties of grass are used.

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:

Kenya

Region/ State/ Province:

Kakamega County in western Kenya

Further specification of location:

Khalaba Ward, Matungu Sub-county in Kakamega County

Specify the spread of the Technology:

• evenly spread over an area

If the Technology is evenly spread over an area, specify area covered (in km2):

0.003804

Is/are the technology site(s) located in a permanently protected area?

No

Map

×

2.6 Date of implementation

Indicate year of implementation:

2019

2.7 Introduction of the Technology

Specify how the Technology was introduced:

• as part of a traditional system (> 50 years)
• through projects/ external interventions

Comments (type of project, etc.):

The technology has been practiced by some farmers in the past. The ProSoil project came in to improve on the farmers' knowledge about the technology and incorporated improvements in terms of slope measurements to determine where to locate the barriers on the farm.

3.1 Main purpose(s) of the Technology

• improve production
• reduce, prevent, restore land degradation
• protect a watershed/ downstream areas – in combination with other Technologies
• preserve/ improve biodiversity
• adapt to climate change/ extremes and its impacts

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

Land use mixed within the same land unit:

Yes

Specify mixed land use (crops/ grazing/ trees):

• Agroforestry

Cropland

• Annual cropping
• Perennial (non-woody) cropping
• Tree and shrub cropping

Annual cropping - Specify crops:

• fodder crops - other
• fodder crops - grasses
• fodder crops - clover
• oilseed crops - groundnuts
• cereals - maize
• legumes and pulses - beans
• legumes and pulses - soya
• root/tuber crops - cassava

Annual cropping system:

Maize/sorghum/millet intercropped with legume

Tree and shrub cropping - Specify crops:

• fodder trees (Calliandra, Leucaena leucocephala, Prosopis, etc.)
• avocado
• fruits, other
• mango, mangosteen, guava

Number of growing seasons per year:

• 2

Specify:

Crops are grown during the long and short rain seasons.

Is intercropping practiced?

Yes

If yes, specify which crops are intercropped:

Cereals intercropped with legumes.

Is crop rotation practiced?

Yes

If yes, specify:

Some of the plots are fallowed to allow soil regeneration.

Grazing land

Intensive grazing/ fodder production:

• Cut-and-carry/ zero grazing
• Improved pastures

Animal type:

• cattle - dairy and beef (e.g. zebu)
• poultry

Is integrated crop-livestock management practiced?

Yes

If yes, specify:

Manure from livestock is applied to the soil. Crops used on the slope barriers are fodder for livestock.

Products and services:

• economic security, investment prestige
• milk
• manure as fertilizer/ energy production
• eggs
• meat

Species:

cattle - dairy and beef (e.g. zebu)

Count:

3

Species:

poultry

Count:

10

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

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

• No (Continue with question 3.4)

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

• agroforestry
• integrated crop-livestock management
• cross-slope measure

3.6 SLM measures comprising the Technology

vegetative measures

• V1: Tree and shrub cover
• V2: Grasses and perennial herbaceous plants

3.7 Main types of land degradation addressed by the Technology

soil erosion by water

• Wt: loss of topsoil/ surface erosion
• Wg: gully erosion/ gullying

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:

Reducing land degradation (soil erosion) is a secondary objective of the technology.

4.1 Technical drawing of the Technology

Technical specifications (related to technical drawing):

Length of the farm (down the slope): 120 m
Width of the farm (along the contour): 31.7 m
Number of vegetative cross-slop barriers established: 6
Width of barriers: ranges between 0.3 m and 0.5 m
Slope: 4%
Width of the established terraces/ distance between any two barriers: 24 m
Plants used: brachiaria and napier grass (grasses), grevillea and calliandra (trees and shrub), bananas (crops)
1st barrier on the upper side (F) is on a retention ditch
Last barrier (A) is on the upper side of a channel that collects excess runoff and prevents damage to neighbours' farms on the lower side of the farm

Author:

William Akwanyi

Date:

17/02/2023

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):

KES

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

124.21352

4.3 Establishment activities

4.4 Costs and inputs needed for establishment

If you are unable to break down the costs in the table above, give an estimation of the total costs of establishing the Technology:

8000.0

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

The ProSoil project through Welthungerhilfe purchased grass splits and tree seedlings for the farmer(s) and covered the cost of contour surveying.

4.5 Maintenance/ recurrent activities

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

Comments:

Vegetative cross-slope barriers are productive; hence, the costs are balanced by very quick returns.

4.7 Most important factors affecting the costs

Describe the most determinate factors affecting the costs:

Rate of man-days vary from one place to another and also depend on the kind of work.

Exchange rate for January 2023, source: European Commission/ InfoEuro online at https://commission.europa.eu/funding-tenders/procedures-guidelines-tenders/information-contractors-and-beneficiaries/exchange-rate-inforeuro_en

The stated costs are estimates.

5.1 Climate

5.2 Topography

Indicate if the Technology is specifically applied in:

• not relevant

Comments and further specifications on topography:

Farmer's field slope is 4%. Hence, the barriers were spaced 24 m from each other.

5.3 Soils

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:

The area has high agrobiodiversity since most farms are under crops and trees.

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
• individual, titled

Land use rights:

• individual

Water use rights:

• open access (unorganized)
• individual

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

Socio-cultural impacts

Ecological impacts

Water cycle/ runoff

Soil

Specify assessment of on-site impacts (measurements):

No recorded data is available for reference. All are estimates based on the farmer's explanation or as given by her.

6.2 Off-site impacts the Technology has shown

Specify assessment of off-site impacts (measurements):

No recorded data is available for reference. All are estimates based on the farmer's explanation or as given by her.

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

Climate-related extremes (disasters)

Meteorological disasters

6.4 Cost-benefit analysis

How do the benefits compare with the establishment costs (from land users’ perspective)?

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

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?

• 11-50%

6.6 Adaptation

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

No

6.7 Strengths/ advantages/ opportunities of the Technology

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

7.1 Methods/ sources of information

7.3 Links to relevant online information

Title/ description:

Vegetative Barriers for Erosion Control

URL:

https://extension.missouri.edu/publications/g1653

7.4 General comments

1. Provide a function to be able to link the documented SLM to similar work that has been documented in other databases e.g., LandPortal, etc.
2. Some of the impacts (section 6) cannot be quantified.