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

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

2.1 Short description of the Technology

Definition of the Technology:

Trashlines are lines of crop residuals that remain after harvesting, they are formed along the contours.

2.2 Detailed description of the Technology

Description:

Trash lines are crop residues laid in bands across the slope of annual crop fields to conserve soil and water, and to incorporate organic matter into the soil after decomposition. They are formed into ridges across the slope to form semi permeable barriers that decrease the runoff velocity and increase the infiltration duration, but allow passage of excess runoff. They impede runoff and enhance infiltration. They also prevent evaporation of water from the soil thus conserving soil moisture. Different dimensions and spacing as practiced by farmers have given rise to different structures depending on availability of materials and tools. Thus there are large and small, fixed and mobile trash lines, spaced about 15 m apart. The position of most trash lines is not fixed but instead new trash is placed 3 to 5m up slope each season.

Purpose of the Technology: Trash lines allow water to infiltrate into the soil in the area directly beneath them, and require little labour to construct but frequent maintenance. Trash lines form semi-permeable barriers across the slope that decrease the surface runoff velocity and increase the infiltration duration of impounded water, but allow passage of excess runoff. As a result, the amount of infiltrated water increases and the runoff volume and its erosive power decrease. Additionally, retention of sediment in the trash results in reduced soil and nutrient losses. Trash lines require low labor.

Establishment / maintenance activities and inputs: Farmers in Embu utilizes the crop residuals after harvesting. The most common used type of crop residual used in Embu district is maize stovers that are left behind after harvesting. They are laid down in a row along the contour and left to decompose after sometime leaving a line of rich organic matter. They do very well when practiced with conservation agriculture. This is very common in the lower Mbeere District.

Natural / human environment: In other areas, cereal stover (straw) and weeds that are collected during primary cultivation (hand hoeing), and heaped in strips along the approximate contour are used as trash lines. Creeping grasses should not be used in trash lines, they can alternatively be decomposed in bundles, and then used as mulch in nearby banana plantations. Trash lines can also be constructed on hillside fields where annual crops, including sorghum, finger millet, beans and peas, are grown.The recommended spacing between the improved trash lines is 5–10 m, depending on the slope: the steeper the closer. The amount of material available determines the cross section of each trash line (typically ±0.5 m wide and ±0.3 m high).

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:

Eastern Province

Further specification of location:

Embu North District

Specify the spread of the Technology:

• evenly spread over an area

If precise area is not known, indicate approximate area covered:

• 1-10 km2

Map

×

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:

• through land users' innovation

3.1 Main purpose(s) of the Technology

• improve production
• reduce, prevent, restore land degradation
• adapt to climate change/ extremes and its impacts
• create beneficial economic impact

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

Cropland

• Annual cropping
• Tree and shrub cropping

Annual cropping - Specify crops:

• cereals - maize

• coffee

Specify:

Longest growing period in days: 180, Longest growing period from month to month: January to June

Comments:

Major land use problems (compiler’s opinion): Reduction of soil erosion and excessive evaporation
Major land use problems (land users’ perception): Increase of organic matter to increase nutrients

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

• improved ground/ vegetation cover
• water harvesting
• irrigation management (incl. water supply, drainage)

3.6 SLM measures comprising the Technology

structural measures

• S6: Walls, barriers, palisades, fences

3.7 Main types of land degradation addressed by the Technology

soil erosion by water

• Wt: loss of topsoil/ surface erosion

Comments:

Main causes of degradation: soil management

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

Technical specifications (related to technical drawing):

The technical drawing on the left side shows rows of maize stovers that are laid down along a contour line after harvesting.

Location: Embu North District. Eastern province
Date: 02/09/2011

Technical knowledge required for field staff / advisors: moderate
Technical knowledge required for land users: high

Main technical functions: control of dispersed runoff: retain / trap

Structural measure: Trashline
Vertical interval between structures (m): 5
Spacing between structures (m): 15
Height of bunds/banks/others (m): 0.5
Width of bunds/banks/others (m): 1
Length of bunds/banks/others (m): 30

Construction material (other): maize stovers
Slope (which determines the spacing indicated above): 8%

Author:

Paul Kahiga, 62000-00200 Nairobi

4.2 General information regarding the calculation of inputs and costs

other/ national currency (specify):

Kshs

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

100.0

4.3 Establishment activities

4.4 Costs and inputs needed for establishment

4.5 Maintenance/ recurrent activities

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

Comments:

Machinery/ tools: Pangas
Labour

4.7 Most important factors affecting the costs

Describe the most determinate factors affecting the costs:

Availability of crop residuals and labour are the most determinate factors affecting the costs.

5.1 Climate

5.2 Topography

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.

Soil fertility: High
Soil drainage/infiltration: Good
Soil water storage capacity: Medium

5.4 Water availability and quality

5.5 Biodiversity

5.6 Characteristics of land users applying the Technology

Indicate other relevant characteristics of the land users:

Land users applying the Technology are mainly common / average land users
Population density: 10-50 persons/km2
Annual population growth: 0.5% - 1%
70% of the land users are average wealthy.

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, titled

Land use rights:

• individual

Water use rights:

• open access (unorganized)

5.9 Access to services and infrastructure

6.1 On-site impacts the Technology has shown

Socio-economic impacts

Production

Socio-cultural impacts

Ecological impacts

Water cycle/ runoff

Soil

Biodiversity: vegetation, animals

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

Comments:

Farmers in the lower Mbeere District have been uprooting maize stovers to increase weight so as to prevent the trash being carried away by strong wind

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

Comments:

There is a moderate trend towards spontaneous adoption of the Technology

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