Muthoni Mary Njagy
有助于对技术进行记录/评估的机构名称（如相关）CDE Centre for Development and Environment (CDE Centre for Development and Environment) - Switzerland
Tree line with adjacent grass strips as example of a productive and protective riparian area at Kapingazi River
On the south-eastern slopes of Mt. Kenya, the conditions are ideal for agricultural activities. There is plenty of rainfall (2100 mm/year) which is usually reliable. However in the year 2000, the river Kapingazi dried up for the first time since many decades during a dry spell. This led to community activities that finally came up with a system of vegetative interventions to strengthen the riparian zones. The intervention consists of tree planting and establishment of grass strips along the river. Napier grass is planted to stabilize steep slopes and to supply material for the construction of tea baskets.
Purpose of the Technology: The goals of this technology are manifold. Firstly, the vegetation prevents surface water and eroded soil flowing from the agricultural fields directly into the river. Therefore, sediments and chemicals used on the field are retained in the riparian soils and do not pollute the river. Surface water flow from runoff during heavy storms is slowed down and infiltration on soils covered by grass and trees is increased. As a result more groundwater is recharged during the wet seasons, which can be released during the dry season. Thus peak or flood flows are reduced and low flows are improved. Damage during flood flows on the riverbank (through erosion and destabilizing the riparian vegetation) as well as damages of floods downstream can be reduced or avoided.
Establishment / maintenance activities and inputs: Before planting the indigenous trees, water guzzlers like eucalyptus trees were cut down. Indigenous seedlings were planted right along the river at a distance of 2m. Between the trees and the tea plantation a grass strip of up to 10m is established. Some trees were planted scattered on the grass strip. The young trees are surrounded by grasses which are cut regularly every 2 weeks. This reduces competition and enhances growth of the trees. As soon as the trees are big enough, they function as a source of firewood, they can be pruned every 5 months.
Natural / human environment: The studied plot is situated right below the natural mountain forest of Mt. Kenya at the south-eastern slope. The source of Kapingazi River can be found at 1.5 km of walking distance upslope of the plot. Agricultural circumstances are good because of the fertile, volcanic plots and the abundant precipitations. However, the terrain is quite steep.
The zone which is used for tea production reaches from an elevation of 1700 m.a.s.l to 2000 m.a.s.l. Most tea farmers own between 4 and 20 acres. The area of the riparian zone covers 6 m from the river edge and belongs to the government. Since the harvest of the tea leaves requires a high labour input, local workers are hired. Most of the harvest is done during the rainy season because the tea plants are growing fast in this period. For the tea production only the youngest leaves are used, transported in a basket on the worker’s back to the tea factory in the evening.
- < 0.1 平方千米（10 公顷）
Since the technology is only used by one farmer at a single spot, it does not make sense to indicate the area. Furthermore, the length along the river is more important than the area.
In the year 2002 the new constitution obliged the government to take care of the water resources. The instrument for this were the WRUA (Water Resource Users Associations), local initiatives of land users that promote protective measures along the rivers.
年作 - 具体指明作物:
- 饲料作物 - 草
乔木和灌木种植 - 指定作物:
Longest growing period in days: 60 Longest growing period from month to month: april to may Second longest growing period in days: 60 Second longest growing period from month to month: november to december
Major crop: Tea and Napier grass
Major land use problems (compiler’s opinion): The main land use problems are pollution of the riverwater, low rainwater storage that provokes floods, too few water during the dry season and riverbank erosion.
Major land use problems (land users’ perception): The main problem is the few water in the dry season that prevents irrigation.
Type of cropping system and major crops comments: Additionally, few food crops are planted in a relatively small homegarden.
Main measures: vegetative measures
Type of vegetative measures: aligned: -along boundary, scattered / dispersed
Main type of degradation addressed: Hp: decline of surface water quality, Hw: reduction of the buffering capacity of wetland areas
Secondary types of degradation addressed: Bs: quality and species composition /diversity decline, Hs: change in quantity of surface water
Main causes of degradation: deforestation / removal of natural vegetation (incl. forest fires) (Riparian trees were chopped down.), education, access to knowledge and support services (People didn't know about the consequences of the deforestation.), planting directly next to river
The area between the river and the tea plantation is used to establish a riparian habitat. Trees are planted along the river and also on the adjacent grazing land. The grass is cut regularly and used as fodder. A bee hive was installed to generate additional income.
Location: Manyatta. Embu / Eastern Province
Technical knowledge required for field staff / advisors: low
Technical knowledge required for land users: low
Main technical functions: improvement of ground cover, increase of infiltration, sediment retention / trapping, sediment harvesting
Secondary technical functions: promotion of vegetation species and varieties (quality, eg palatable fodder)
Aligned: -along boundary
Vegetative material: T : trees / shrubs
Number of plants per (ha): 30
Vertical interval within rows / strips / blocks (m): 3
Scattered / dispersed
Vegetative material: G : grass
Trees/ shrubs species: indigenous trees, Napier grass
Grass species: normal grass
|1.||Tree planting||During rainy season|
|2.||Replanting of seedlings which dried up|
|3.||Planting trees||At the beginning of the rainy season|
|劳动力||Tree planting during rain season||Persons/day||6.0||3.3333333||20.0||100.0|
|劳动力||Replanting of seedlings||Persons/day||2.0||3.333333||6.67||100.0|
|劳动力||Planting trees before rain season||Persons/day||8.0||3.333333||26.67||100.0|
|植物材料||Seedlings for replanting||pieces||20.0||0.111||2.22||100.0|
Duration of establishment phase: 1 month(s)
|1.||Weeding the area around the trees to get fodder and boost the tree growth||every 2 weeks for 4 years|
|2.||Weeding the lawns for better growth of the trees and for fodder||every 2 weeks during raining season|
|劳动力||Weeding the area around the trees||Persons/day||16.0||3.33333||53.33||100.0|
|劳动力||Weeding the lawns||Persons/day||64.0||3.33333||213.33||100.0|
Machinery/ tools: Jembe (Machete)
The costs were calculated for a riparian area with a length of 100m and a width of 10m, since hectares are difficult to apply on a riparian context. The determinant factor for the costs is labour. In this case, the costs are very low because the trees were only planted every 10 metres along the riparian. The seedlings have to be bought in a nursery. Most of the bushes regrow naturally and do not need any management.
Some of the seedlings had to be replanted, because they dried up. The required equipment like a spade is available on nearly every farm or can be borrowed from neighbours and is thus not added to the costs.
- < 250毫米
- > 4,000毫米
Most of the rain falls during the rainy seasons from April-May and Oct-Nov.
Thermal climate class: subtropics. http://www.mappedplanet.com/klima/klimadiagramm-39729-Nanyuki,Kenia
- 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.
- 非常深（> 120厘米）
Soil fertility is medium
Soil drainage / infiltration is good
Soil water storage capacity is very high
Availability of surface water: Also excess and poor/none
- > 收入的50%
Land users applying the Technology are mainly Leaders / privileged
Population density: > 500 persons/km2
Off-farm income specification: Owner is a member of the parliament.
- < 0.5 公顷
- 0.5-1 公顷
- 1-2 公顷
- > 10,000公顷
Land user was a former member of parliament
Pruning of trees
Grass for basket production.
Pruning the trees
Livelihood and human well-being
Through the increase of the water quality, the technology improves the access to clean water.
10% of all the riparian land users have adopted the technology
70% of land user families have adopted the Technology with external material support
Comments on acceptance with external material support: 10% of all the riparian land users have adopted the technology. The external support was the provision of seedlings.
30% of land user families have adopted the Technology without any external material support
There is a moderate trend towards spontaneous adoption of the Technology
Comments on adoption trend: Through the action of several organisations, the attention of the land users is drawn to a proper riparian management.
The river does not dry up easily during dry seasons. The grass yield can be used for fodder purposes.
How can they be sustained / enhanced? disseminating the knowledge among the farmers.
A vivid and stable riparian ecosystem is the key to ensure biodiversity and stability of the riverbanks. This leads to a smaller vulnerability to floods or droughts and combats degradation.
How can they be sustained / enhanced? continuous awareness raising among the land users.
|Labour input for weeding is high||cutting grass at a bigger height|