Chagga Homegardens [Tanzania, United Republic of]

technologies_1337 - Tanzania, United Republic of

Completeness: 69%

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:

Hemp Andreas

University of Bayreuth


SLM specialist:

Hemp Claudia

University of Würzburg


Name of project which facilitated the documentation/ evaluation of the Technology (if relevant)
Book project: SLM in Practice - Guidelines and Best Practices for Sub-Saharan Africa (SLM in Practice)
Name of the institution(s) which facilitated the documentation/ evaluation of the Technology (if relevant)
Universität Bayreuth (UBT) - Germany
Name of the institution(s) which facilitated the documentation/ evaluation of the Technology (if relevant)
Julius-Maximilians-Universität Würzburg (JMU) - 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:


2. Description of the SLM Technology

2.1 Short description of the Technology

Definition of the Technology:

The Chagga homegardens are traditional, densely planted ‘banana forests’ with a scattered upper tree layer.

2.2 Detailed description of the Technology


The complex multicropping system evolved over several centuries through a gradual transformation of the natural forest on the footslopes of Kilimanjaro. A Chagga homegarden has an average size of 0.68 ha and integrates numerous multipurpose trees and shrubs with food crops, and stall-fed animals, without a specific spatial arrangement. However, vertically, the following 4 stories/canopies can be distinguished: (1) food crops: taro, beans, vegetables and fodder herbs / grasses; (2) coffee: 500-1,400 plants/ha; (3) banana: primary crop; 50% cover; 330-1,200 clumps/ha; and (4) Trees, such as Cordia abyssinica, Albizia schimperiana and Grevillea robusta. The trees provide shade for coffee, act as live fences, provide medicines, firewood, fodder, mulching material, bee forage; and some have pesticidal properties (e.g. Rauwolfia caffra). This multilayer system maximizes the use of limited land in a highly populated area, making sustained production possible with a minimum of external inputs, minimizes risk (less production failure, increased resistance against droughts and pests) and ensures at the same time environmental protection. The large species diversity provides both subsistence and cash crops. Parts of the homegarden area are irrigated and drained by a network of over 1000 canals and furrows tapping runoff from the montane forest. However, many systems are now in disrepair.

Natural / human environment: Starting in the 1930s when coffee took more space from the food production, it became necessary to expand food production to the lowlands. Today, the Chagga highland homegarden works only in combination with a lowland field where maize, millet, beans, sunflower and groundnuts are grown to ensure food security.

2.3 Photos of the Technology

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


Tanzania, United Republic of

Further specification of location:

Mt. Kilimanjaro Region


Total area covered by the SLM Technology is 1200 km2.

individual homegardens are 0.68 ha on average

2.6 Date of implementation

If precise year is not known, indicate approximate date:
  • more than 50 years ago (traditional)

2.7 Introduction of the Technology

Specify how the Technology was introduced:
  • as part of a traditional system (> 50 years)

3. Classification of the SLM Technology

3.1 Main purpose(s) of the Technology

  • improve production

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

Land use mixed within the same land unit:


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



  • Annual cropping
  • Perennial (non-woody) cropping
  • Tree and shrub cropping
Annual cropping - Specify crops:
  • fodder crops - grasses
  • fodder crops - other
  • vegetables - other
  • Taro
Perennial (non-woody) cropping - Specify crops:
  • banana/plantain/abaca
Tree and shrub cropping - Specify crops:
  • avocado
  • coffee, open grown
Number of growing seasons per year:
  • 2
Forest/ woodlands

Forest/ woodlands

  • Cordia abyssinica, Albizia schimperiana and Grevillea robusta
Products and services:
  • Fuelwood
  • Other forest products
  • Grazing/ browsing

Type of cropping system and major crops comments: Chagga homegardens are traditional, densely planted ‘banana forests’ with a scattered upper tree layer

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:


Specify mixed land use (crops/ grazing/ trees):
  • Agroforestry
Forest/ woodlands

Forest/ woodlands

3.4 Water supply

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

3.5 SLM group to which the Technology belongs

  • agroforestry
  • home gardens

3.6 SLM measures comprising the Technology

vegetative measures

vegetative measures

  • V1: Tree and shrub cover
management measures

management measures

  • M5: Control/ change of species composition

Type of vegetative measures: scattered / dispersed

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
chemical soil deterioration

chemical soil deterioration

  • Cn: fertility decline and reduced organic matter content (not caused by erosion)

Main type of degradation addressed: Wt: loss of topsoil / surface erosion, Cn: fertility decline and reduced organic matter content

3.8 Prevention, reduction, or restoration of land degradation

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

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

4.1 Technical drawing of the Technology

Technical specifications (related to technical drawing):

Typical chagga homegarden on a 45% slope at 1400 m a.s.l. with 4 vegetation layers: open light upper canopy with Albizia schimperiana (up to 20 m high); upper shrub layer with banana (4-6 m); a lower shrub layer with coffee (1.5-2 m) and food crops such as taro (< 1.5 m) -2.5 m; 3-6 m; 5-30 m

Mt. Kilimanjaro Region

Date: 2009

Technical knowledge required for field staff / advisors: moderate

Technical knowledge required for land users: moderate

Main technical functions: control of raindrop splash, stabilisation of soil (eg by tree roots against land slides), increase in organic matter, increase in nutrient availability (supply, recycling,…), increase of infiltration, increase of biomass (quantity), promotion of vegetation species and varieties (quality, eg palatable fodder)

Scattered / dispersed
Vegetative material: T : trees / shrubs

Trees/ shrubs species: Cordia abyssinica, Albizia schimperiana, Grevillea robusta, Rauwolfia caffra, Persea americana

Fruit trees / shrubs species: banana, avocado, mango

Perennial crops species: taro, coffee

Grass species: fodder herbs / grasses

Change of land use type: from natural forests to agroforest


Hemp, A. / Hemp, C.

4.2 General information regarding the calculation of inputs and costs

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


Specify currency used for cost calculations:
  • USD

4.3 Establishment activities

Activity Timing (season)
1. Transforming the native forest: trees that provided fodder, fuel, fruits, medicines, shade, timber, bee forage, anti-pest properties are retained while the less useful species are eliminated
2. Introduction of new fruit and timber tree species, such as avocado, mango, Grevillea robusta, Persea americana
3. Planting crops species (banana, coffee, taro, beans, vegetables)
4. Establishment of irrigation/drainage channels
5. Terracing or building of bunds in steep places

4.5 Maintenance/ recurrent activities

Activity Timing/ frequency
1. Planting, tending and harvesting of bananas, taro, yams / Opening up the canopy to ensure better fruiting of the coffee all year round
2. Spacing out the banana stools; Manuring crops (using dung from the stall-fed livestock and compost)
3. Lopping fodder trees/shrubs; Pruning and spraying against coffee berry disease and leaf rust
4. Maintaining irrigation furrows; Coffee harvest August to January
5. Tending and milking the stall-fed cows (typically only one cow) / Mulching, terrace maintenance (soil erosion prevention in general)

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 Planting, tending and harvesting unit 1.0 300.0 300.0 100.0
Equipment Tools unit 1.0 45.0 45.0 100.0
Fertilizers and biocides Compost / manure unit 1.0 100.0 100.0 100.0
Total costs for maintenance of the Technology 445.0
Total costs for maintenance of the Technology in USD 445.0

Machinery/ tools: axes, hoes, pangas (machetes)

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
Specifications/ comments on rainfall:

depending on slope orientation and altitude

Agro-climatic zone
  • sub-humid

Thermal climate class: tropics

Tropical montane; bimodal: long rains in March-May, short rains in Nov-Dec

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.
Comments and further specifications on topography:

Slopes on average: Also steep (31-60%)

Altitudinal zone: 1000-1800 m.a.s.l.

Landforms: Orientation south / south-east

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)
Topsoil organic matter:
  • high (>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 high

5.5 Biodiversity

Species diversity:
  • high

5.6 Characteristics of land users applying the Technology

Market orientation of production system:
  • mixed (subsistence/ commercial)
Relative level of wealth:
  • poor
Individuals or groups:
  • individual/ household
Level of mechanization:
  • manual work
Indicate other relevant characteristics of the land users:

Land users applying the Technology are mainly disadvantaged land users

Population density: > 500 persons/km2

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)?
  • small-scale

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

Land ownership:
  • individual, not titled
  • individual, titled
Land use rights:
  • individual

traditional clan regulations (land cannot be sold to outsiders)

6. Impacts and concluding statements

6.1 On-site impacts the Technology has shown

Socio-economic impacts


wood production

Comments/ specify:

Fuelwood production 1.5-3 m3/ha/year

risk of production failure


product diversity

Comments/ specify:

185 kg beans/ha; 410 kg coffee/ha; 400 bunches of banana /ha; ca. 30 kg honey/ha

Income and costs


Comments/ specify:

increased labour efficiency

Other socio-economic impacts

value of gene pool

Comments/ specify:

for breeding programmes to improve crop varieties for multistorey cropping systems

Socio-cultural impacts

food security/ self-sufficiency


health situation


preservation of traditional knowledge


Ecological impacts


soil cover


soil loss

Biodiversity: vegetation, animals

plant diversity

Comments/ specify:

over 500 plant species including 400 non-cultivated plants

animal diversity


pest/ disease control

Other ecological impacts



biodiversity / crop diversity

Comments/ specify:

? land use change from natural forest to agroforest

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

Climate-related extremes (disasters)

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

Other climate-related consequences

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

the system has a high buffer capacity (micro-climate, biodiversity, irrigation)

6.4 Cost-benefit analysis

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


Long-term returns:

very positive

6.5 Adoption of the Technology

  • > 50%
Of all those who have adopted the Technology, how many did so spontaneously, i.e. without receiving any material incentives/ payments?
  • 91-100%

100% of land user families have adopted the Technology without any external material support

Comments on adoption trend: Locally well adopted traditional land use system, covering an area of approximately 1200 km2; further spread at local level is not possible due to land shortage.

6.7 Strengths/ advantages/ opportunities of the Technology

Strengths/ advantages/ opportunities in the compiler’s or other key resource person’s view
this system allows for maintaining high biodiversity at the same time with diversified production of fruits, vegetables, timber, medicinal products etc.

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?
High demand of wood, low coffee prices and the introduction of sun-tolerant coffee varieties endanger the homegardens incentive-based tree planting in the gardens to reduce the pressure on the forest
Weaknesses/ disadvantages/ risks in the compiler’s or other key resource person’s view How can they be overcome?
Productivity of Chagga homegardens is not optimal (1) Replace the less productive trees / shrubs with fast growing nitrogen fixing species; (2) improve animal husbandry (e.g. to increase lactation period), (3) improve apiculture,
Productivity of Chagga homegardens is not optimal (4) introduce new crop varieties using the gene pool developed by natural and farmer selection, (5) use fertilizers,
Productivity of Chagga homegardens is not optimal (6) improve coffee production: certified production (organic, fair trade) to fetch higher prices, (7) replace old coffee plants with new ones, (8) integrated pest management, (9) facilitate access to capital for farm investments
Productivity of Chagga homegardens is not optimal (10) improve erosion control (terraces and bunds), (11) include productive fruit trees, (12) improve advisory services
Water management causes nutrient loss in the gardens and water shortages on the lower slopes improve efficiency of furrows: Install pipes and surfacing by cement, protect river banks from cultivation

7. References and links

7.2 References to available publications

Title, author, year, ISBN:

Hemp, A. (1999): An ethnobotanical study on Mt. Kilimanjaro. Ecotropica 5: 147-165

Title, author, year, ISBN:

Hemp, A. (2006): The banana forests of Kilimanjaro. Biodiversity and conservation of the agroforestry system of the Chagga Homegardens. Biodiversity and Conservation 15(4): 1193-1217.

Title, author, year, ISBN:

Hemp, C. (2005): The Chagga Home Gardens – relict areas for endemic Saltatoria Species (Insecta: Orthoptera) on Mt. Kilimanjaro. Biological Conservatrion 125: 203-210.

Title, author, year, ISBN:

Hemp, A., C. Lambrechts, and C. Hemp. (in press). Global trends and Africa. The case of Mt. Kilimanjaro. (UNEP, Nairobi)

Title, author, year, ISBN:

Hemp, A., Hemp, C., Winter, C. (2009) Environment and worldview: The Chagga homegardens. In: Clack, T.A.R. (ed.) Culture, history and identity: Landscapes of inhabitation in the Mount Kilimanjar area, Tanzania. BAR International Series 1966, Archaeopress Oxford, pp. 235-303

Title, author, year, ISBN:

Fernandes E.C.M., Oktingati A., Maghembe J. 1985. The Chagga homegardens: a multistoried agroforestry cropping system on Mt. Kilimanjaro (Northern Tanzania) in Agroforestry Systems 2: 73-86

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