Poplar trees for bio-drainage [Kyrgyzstan]

bio-drainage, reduce salinity, favourable microclimate for for plant growth

technologies_1098 - Kyrgyzstan

Completeness: 67%

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:
SLM specialist:
Name of project which facilitated the documentation/ evaluation of the Technology (if relevant)
Book project: where the land is greener - Case Studies and Analysis of Soil and Water Conservation Initiatives Worldwide (where the land is greener)
Name of the institution(s) which facilitated the documentation/ evaluation of the Technology (if relevant)
Kyrgyz Agrarian University (Kyrgyz Agrarian University) - Kyrgyzstan

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:

Poplars planted to lower the ground water table and reduce salinity where irrigation drainage systems have broken down; lucerne cultivated between the tree lines.

2.2 Detailed description of the Technology


In irrigated areas of Central Asia, the drainage system introduced during soviet times has broken down due to lack of maintenance. As a result, water tables have been rising and soil salinity increasing. In the Chui Valley, which is the main crop production area in Kyrgyzstan, approximately 90% of the cultivated land is irrigated for wheat, maize, sugar beet, lucerne and vegetables. Of this, approximately one third (ca. 320,000 ha) is degraded due to loss of fertility, salinisation and waterlogging.
The individual initiative described here - poplar planting - has been applied on a degraded plain (about 400 m a.s.l.), under semi-arid conditions on a plot of 5 hectares. Though initially planted for timber, an important side effect was noted by the farmer in question. Poplar trees, well known for their tolerance to waterlogging and salinity, provide ‘bio-drainage’. Excess water is rapidly taken up by the root system and transpired through the dense foliage. Within the plantation the humidity level of the lower layers of air is increased, thus reducing the influence of the dry, hot winds. A more favourable microclimate for plant growth is thus created. Simultaneously the original purpose of planting - to obtain cheap timber and firewood - is achieved through the rapid growth of the trees: there is a severe shortage of wood locally.
The varieties used include the local Populus alba and Populus nigra as well as a hybrid from Kazakhstan, P. pyramidalis. The trees are planted in rows about 5 metres wide, separated by 10-15 metre strips planted with Medicago sativa (lucerne) and Bromus inermis (a grass), both of which are grown for hay (see technical drawing). Around 3,000 saplings are needed per hectare. The young poplars require irrigating during the first year before their roots can reach the water table. The trees are weeded and their lower branches pruned to encourage straight and fast growth. They are thinned twice before they are 14 years old: these thinnings can be sold. The poplars then remain until they are 20-25 years old and suitable for felling. The output of commercial timber of a poplar plantation is 3,000 m2 per hectare (1 m2 per mature tree). Slow-growing/sick trees, as well as pruned branches, are used as firewood - which can amount to 20-30 m3 per hectare. The cycle begins again after approximately 10 years, when new saplings are planted between the existing, thinned, lines of poplars. Desalinisation of the soil takes 10 years or a little longer, when it again becomes suitable for irrigated cereal cropping.

2.3 Photos of the Technology

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



Region/ State/ Province:

Besh-Terek, Chui valley,

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):



Total area covered by the SLM Technology is 0.05 km2.

2.7 Introduction of the Technology

Specify how the Technology was introduced:
  • during experiments/ research

3. Classification of the SLM Technology

3.1 Main purpose(s) of the Technology

  • reduce, prevent, restore land degradation

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
Annual cropping - Specify crops:
  • fodder crops - alfalfa
Number of growing seasons per year:
  • 1

Longest growing period in days: 180; Longest growing period from month to month: Mar - Sep

Forest/ woodlands

Forest/ woodlands

Type of tree:
  • Populus species

Major food crop: Poplar, lucerne (alfalfa), wheat

Major land use problems (compiler’s opinion): Irrigation drainage systems have deteriorated (silted up, choked with weeds and reeds) due to lack of maintenance. This has led to a raised water table, waterlogging and increased salinity, thus seriously affecting productivity and making cultivation of some crops impossible. Farmers’ incomes have significantly reduced as a result.

Constraints of wastelands / deserts / glaciers / swamps

3.5 SLM group to which the Technology belongs

  • forest plantation management
  • improved ground/ vegetation cover

3.6 SLM measures comprising the Technology

agronomic measures

agronomic measures

  • A1: Vegetation/ soil cover
vegetative measures

vegetative measures

  • V1: Tree and shrub cover

Type of agronomic measures: legume inter-planting

Type of vegetative measures: aligned: -against wind

3.7 Main types of land degradation addressed by the Technology

chemical soil deterioration

chemical soil deterioration

  • Cn: fertility decline and reduced organic matter content (not caused by erosion)
  • Cs: salinization/ alkalinization
physical soil deterioration

physical soil deterioration

  • Pw: waterlogging

Secondary types of degradation addressed: 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:
  • restore/ rehabilitate severely degraded land

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

4.1 Technical drawing of the Technology

Technical specifications (related to technical drawing):

Alternating strips of poplar trees for bio-drainage, and lucerne for fodder. Drainage channels (left) are spaced at 50 metres apart.

Technical knowledge required for field staff / advisors: moderate

Technical knowledge required for land users: moderate

Main technical functions: lower ground water level, decrease waterlogging & improve soil fertility, reduce risk of salinisation

Secondary technical functions: reduction in wind speed, increased air humidity & cooling effect

Aligned: -against wind
Vegetative material: T : trees / shrubs

Trees/ shrubs species: Poplars (Populus alba, Populus nigra, P.pyramidalis)


Mats Gurtner

4.2 General information regarding the calculation of inputs and costs

Specify currency used for cost calculations:
  • USD

4.3 Establishment activities

Activity Timing (season)
1. Set up tree nursery one year before planting: take cuttings about
2. Demarcate lines in field.
3. Dig drainage trenches in the marshy area (50 cm deep, 50 cm wide, (end of summer, early autumn)
4. Plough where seedlings of the poplars are to be planted.
5. Transplant tree seedlings from the nursery to the field . in spring
6. Irrigate the seedlings by furrow for one year.
7. Protect the area from animals.
8. Plant lucerne . in first year after planting of poplars

4.4 Costs and inputs needed for establishment

Specify input Unit Quantity Costs per Unit Total costs per input % of costs borne by land users
Labour All the Labour ha 1.0 350.0 350.0 100.0
Labour Machine use ha 1.0 100.0 100.0 100.0
Labour Animal traction ha 1.0 5.0 5.0 100.0
Equipment Tools ha 1.0 15.0 15.0
Plant material Seeds ha 1.0 20.0 20.0 1.0
Plant material Seedlings ha 1.0 350.0 350.0 1.0
Plant material Nursery ha 1.0 80.0 80.0 1.0
Total costs for establishment of the Technology 920.0
Total costs for establishment of the Technology in USD 920.0

Duration of establishment phase: 24 month(s)

4.5 Maintenance/ recurrent activities

Activity Timing/ frequency
1. Prune lower branches of the trees to encourage tall and straight
2. Continue protection of the plot (because of lucerne).
3. Cut lucerne for hay . /4 times per year
4. Weed control (main weeds are Chenopodium album,

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 All the labour ha 1.0 25.0 25.0 100.0
Equipment Machine use ha 1.0 5.0 5.0 100.0
Total costs for maintenance of the Technology 30.0
Total costs for maintenance of the Technology in USD 30.0

Machinery/ tools: shovel, axe, saw

Labour for establishment and maintenance are provided by the farmer and his family. After 10–15 years trees are
thinned for timber and the cycle begins again – with reduced establishment costs: new saplings are planted between the
existing, thinned, lines of poplars. On two sides the plot is protected by a drainage ditch and a concrete canal protect the plot respectively. Furthermore, there is an agreement with the neighbours not to let the animals graze the lucerne. However after the last cut of lucerne animals are allowed to graze the plot.

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
Agro-climatic zone
  • semi-arid

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.

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)
Soil texture (topsoil):
  • medium (loamy, silty)
Topsoil organic matter:
  • medium (1-3%)
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 very low - low

Soil drainage / infiltration is poor

5.6 Characteristics of land users applying the Technology

Market orientation of production system:
  • subsistence (self-supply)
  • commercial/ market
Off-farm income:
  • 10-50% of all income
Indicate other relevant characteristics of the land users:

Off-farm income specification: this individual is an employee of the regional agricultural department and has a small business

Market orientation of production system: Thinned poplar saplings, timber and firewood from prunings for market

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

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

Land ownership:
  • individual, titled
Land use rights:
  • individual

6. Impacts and concluding statements

6.1 On-site impacts the Technology has shown

Socio-economic impacts


fodder production

Comments/ specify:

Lucerne between tree lines

fodder quality

Comments/ specify:

Lucerne between tree lines

wood production

Income and costs

farm income



Other socio-economic impacts

input contstraints

Comments/ specify:

Not all the farmers have enough resources for introduction of this technology (equipment,

main benefit

Comments/ specify:

However, short-term benefit from lucerne as fodder and from firewood through pruning

Socio-cultural impacts

SLM/ land degradation knowledge


Ecological impacts

Water cycle/ runoff

excess water drainage


soil moisture

Climate and disaster risk reduction

fire risk


wind velocity

Other ecological impacts

soil fertility

Comments/ specify:

Due to lucerne: 100–130 kg of N



6.2 Off-site impacts the Technology has shown

wind transported sediments


General drop of water table


6.4 Cost-benefit analysis

How do the benefits compare with the establishment costs (from land users’ perspective)?
Short-term returns:


Long-term returns:

very positive

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

  • single cases/ experimental
If available, quantify (no. of households and/ or area covered):

1 household

Of all those who have adopted the Technology, how many did so spontaneously, i.e. without receiving any material incentives/ payments?
  • 0-10%

There is a little trend towards spontaneous adoption of the Technology

Comments on adoption trend: A single farmer has developed this technology. It should be possible to spread the technology among other farmers but financial support (eg interest-free credit) will need to be provided. A recent assessment has showed that there is growing interest in the system by farmers in the region. Additionally, in the lower Yanvan Valley of Tajikistan, a similar bio-drainage system has been described - using poplars and mulberry trees. In that situation wheat is planted in association with the trees.

6.7 Strengths/ advantages/ opportunities of the Technology

Strengths/ advantages/ opportunities in the compiler’s or other key resource person’s view
Positive ecological effect: salinity and area of marshy land can be reduced and waterlogged soils reclaimed

How can they be sustained / enhanced? Awareness raising and training of
farmers to show the effect of poplar trees on reduction of waterlogging
and salinisation.
Rapid benefit through the production of lucerne and grass. Long-term production of valuable firewood and timber (both are in short supply)

How can they be sustained / enhanced? Show the economic benefits of additional lucerne production and timber and firewood; demonstrate marketing opportunities.

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

Weaknesses/ disadvantages/ risks in the compiler’s or other key resource person’s view How can they be overcome?
The implementation of the technology is not possible for all land users due to input and labour constraints Financial support, better organisation/
share of equipment.
Major benefit from timber production comes only after 25 years Create awareness about additional short-term benefits, especially firewood
and fodder, as well as the long-term effects and the sustainability of the system.
Cannot be replicated by all farmers in the valley at the same density as the market for trees (timber, firewood) will be saturated, and trees can never completely take the place of irrigated food crops: nevertheless
the benefits will extend to those growers through the drainage function of the poplars
A new overall production system will have to be worked out for the region.
The case reported here works in its current design because of its isolated ‘island effect’: if more farmer grew poplar, the same bio-drainage effect could be achieved over the whole valley at a lower density of trees per
unit area, implying a larger proportion of cultivable land.

7. References and links

7.1 Methods/ sources of information

7.2 References to available publications

Title, author, year, ISBN:

Budaychiev D (2002) The prospects for hybrid poplar forest plantations. Resolving problems and the strategy of reformingagrarian science. News of Kyrgyz Agrarian Academy Vol. 2, Issue 3, 4.1 Bishkek

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