Shelterbelts for farmland in sandy areas [China]
- Creation:
- Update:
- Compiler: Meili WEN
- Editor: –
- Reviewer: David Streiff
Farmland shelter belt
technologies_1366 - China
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Expand all Collapse all1. General information
1.2 Contact details of resource persons and institutions involved in the assessment and documentation of the Technology
SLM specialist:
Wang Dogmei
China
Name of the institution(s) which facilitated the documentation/ evaluation of the Technology (if relevant)
GEF/OP12 Gansu Project (GEF/OP12 Gansu Project) - China1.3 Conditions regarding the use of data documented through WOCAT
When were the data compiled (in the field)?
20/05/2002
The compiler and key resource person(s) accept the conditions regarding the use of data documented through WOCAT:
Ja
1.5 Reference to Questionnaire(s) on SLM Approaches
Shelter Belt [China]
The shelter belt is a strip or a row of trees planted in a farmland as a wind barrier to protect crops and reduce wind erosion.
- Compiler: Meili WEN
2. Description of the SLM Technology
2.1 Short description of the Technology
Definition of the Technology:
Belts of trees, planted in a rectangular grid pattern or in strips within, and on the periphery of, farmland to act as windbreaks.
2.2 Detailed description of the Technology
Description:
Shelterbelts to protect cropland are a specific type of agroforestry system comprising certain tall growing tree species. Such shelterbelts around farmland help reduce natural hazards including sandstorms, wind erosion, shifting sand, droughts and frost. They also improve the microclimate (reduced temperature, wind speed, soil water loss and excessive wind-induced transpiration) and create more favourable conditions for crop production. Thus the establishment of shelterbelts plays a crucial role in the sandy drylands that are affected by wind and resultant desertification
especially during winter and spring. Where there is irrigation, the shelterbelts protect the infrastructure from silting-up with wind-borne sediment.
Strips of tall growing species (15-25 m) of poplar (Populus spp.) or willow (Salix spp.) were originally (from 1960s onwards) planted in a 400 by 600 m rectangular grid pattern within extensive areas of cropland, with an extra belt of windbreaks on the windward side (against the prevailing wind). Generally, the distance effectively protected is 15-25 times the tree height. Strips are of variable width, consisting of 2-5 tree lines (1-3 m apart) with trees planted every 1-2 m within the lines. Selective felling is used to maintain adequate growing space and the protective effect of the trees.
The impact of the shelterbelts depends on the planting pattern of the trees (the format of strips and grids), the orientation of the shelterbelts in relation to the wind, the spacing between, and the width of each strip and the type of trees planted. The specific design is primarily based on preventing the negative effects of wind, but depends also on local conditions such as the layout of the land, the location of the roads, farm boundaries and irrigation canals. Ideally the tree strips are perpendicular to the prevailing wind direction, and the angle between the strip and the prevailing wind is never less than 45 degrees. The structure of the strips determines the way the wind is controlled, ranging from blocking the wind
to letting it diffuse through semi-permeable shelterbelts. The best effect is achieved if the wind is not blocked entirely, as this can cause turbulence.
The ownership of the land and the shelterbelts still rests with the state, but management has been more and more transferred to individual households. On condition that the impact of the shelterbelt is not affected, the local forestry agencies now allow some felling of mature trees - on a rotational and selective basis, for timber and firewood. Pine trees (Pinus sylvestris var. mongolica and P. tabulaeformis), which command high value as timber for construction, and fruit (and cash) trees like the apricot tree (Prunus armeniace) are increasingly 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:
China
Region/ State/ Province:
Inner Mongolia Autonomous Region
Map
×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:
- through projects/ external interventions
Comments (type of project, etc.):
USA and domestic.
3. Classification of the SLM Technology
3.1 Main purpose(s) of the Technology
- reduce risk of disasters
3.2 Current land use type(s) where the Technology is applied
Mixed (crops/ grazing/ trees), incl. agroforestry
- Agroforestry
Main products/ services:
major cash crop: maize/wheat
Comments:
Major land use problems (compiler’s opinion): Strong winds in the winter and spring result in serious natural hazards including sand storms, sand encroachment and wind erosion, while dry and hot winds in the summer increase transpiration leading to plant stress and reduced crop yields.
Major land use problems (land users’ perception): Low yield and intensive wind blow in winter and spring.
If land use has changed due to the implementation of the Technology, indicate land use before implementation of the Technology:
Cropland: Ca: Annual cropping
3.3 Further information about land use
Water supply for the land on which the Technology is applied:
- mixed rainfed-irrigated
Number of growing seasons per year:
- 1
Specify:
Longest growing period in days: 150Longest growing period from month to month: May - Sep
3.4 SLM group to which the Technology belongs
- agroforestry
- windbreak/ shelterbelt
3.5 Spread of the Technology
Specify the spread of the Technology:
- evenly spread over an area
If the Technology is evenly spread over an area, indicate approximate area covered:
- 100-1,000 km2
Comments:
Total area covered by the SLM Technology is 500 m2.
Total SWC Technology area is not clear. This technology area data is from Inner Mongolia forest department. Inner Mongolia autonomy region forest statistic data, 1987, P75. Technology beginning year is from: Water and soil conservation bureau, Yellow River irrigation works committee of Department of water and electricity. Water and soil conservation economy benefit thesis collecting,1987, P45-47.
3.6 SLM measures comprising the Technology
vegetative measures
- V1: Tree and shrub cover
management measures
- M1: Change of land use type
Comments:
Main measures: vegetative measures
Type of vegetative measures: aligned: -against wind
3.7 Main types of land degradation addressed by the Technology
soil erosion by wind
- Et: loss of topsoil
- Eo: offsite degradation effects
water degradation
- Ha: aridification
Comments:
Main type of degradation addressed: Et: loss of topsoil, Eo: offsite degradation effects, Ha: aridification
Main causes of degradation: deforestation / removal of natural vegetation (incl. forest fires), poverty / wealth (Lack of captial)
Secondary causes of degradation: overgrazing, education, access to knowledge and support services (Lack of knowledge), Lack of enforcement of legislat./authority
3.8 Prevention, reduction, or restoration of land degradation
Specify the goal of the Technology with regard to land degradation:
- reduce land degradation
Comments:
Main goals: mitigation / reduction of land degradation
4. Technical specifications, implementation activities, inputs, and costs
4.1 Technical drawing of the Technology
4.2 Technical specifications/ explanations of technical drawing
Overview of the shelterbelt layout.
Insert 1: Planting scheme: shelterbelts compromise 2-5 tree lines forming the windbreak about 5-15 m wide and 15-25 m high.
Insert 2: Rectangle grid layout of shelterbelts. Spacing of the rows is denser against the prevailing wind.
Technical knowledge required for field staff / advisors: moderate
Technical knowledge required for land users: low
Main technical functions: increase / maintain water stored in soil, reduction in wind speed, protection from wind erosion, protection from sand encroachment, protection of crops from mechanical damage, reduction in evaporation loss
Secondary technical functions: increase in organic matter
Aligned: -against wind
Vegetative material: T : trees / shrubs
Trees/ shrubs species: Poplars (Populus spp.), willows (Salix spp.), increasingly also pine (Pinus sylvestris var. Mongolic
4.3 General information regarding the calculation of inputs and costs
Specify how costs and inputs were calculated:
- per Technology area
Indicate size and area unit:
ha
Specify currency used for cost calculations:
- US Dollars
Indicate average wage cost of hired labour per day:
1.20
4.4 Establishment activities
Activity | Type of measure | Timing | |
---|---|---|---|
1. | 1 Planning / designing of shelterbelt. | Vegetative | |
2. | 2 Selection and collection of trees seedlings. | Vegetative | |
3. | 3 Clearing and preparing land for planting of shelterbelt in | Vegetative | late autumn and spring |
4. | 3 Clearing and preparing land for planting of shelterbelt in | Vegetative | |
5. | 4 Pits for planting the seedlings are dug | Vegetative | 4 Pits for planting the seedlings are dug |
6. | 5 Tree seedlings are planted | Vegetative | late spring |
7. | 6 After planting each seedling is watered for up to two years. | Vegetative |
4.5 Costs and inputs needed for establishment
Specify input | Unit | Quantity | Costs per Unit | Total costs per input | % of costs borne by land users | |
---|---|---|---|---|---|---|
Labour | Mainly collection and planting | ha | 79.0 | 1.2 | 94.8 | |
Equipment | tools | ha | 1.0 | 5.0 | 5.0 | 100.0 |
Plant material | tree seedlings | ha | 1.0 | 25.0 | 25.0 | |
Total costs for establishment of the Technology | 124.8 |
If land user bore less than 100% of costs, indicate who covered the remaining costs:
USA and domestic projects
Comments:
Duration of establishment phase: 36 month(s)
4.6 Maintenance/ recurrent activities
Activity | Type of measure | Timing/ frequency | |
---|---|---|---|
1. | Watering | Vegetative | after planting /timely |
2. | Pruning of trees. | Vegetative | |
3. | Pest and disease control within shelterbelt. | Vegetative | |
4. | Intermediate/ selective tree felling. | Vegetative |
4.7 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 | Watering and Pruning | ha | 7.0 | 1.2 | 8.4 | 100.0 |
Plant material | tree seedling | ha | 1.0 | 3.0 | 3.0 | 100.0 |
Total costs for maintenance of the Technology | 11.4 |
Comments:
The costs are calculated according to current standards/costs. The original planting is paid for by the state: replanting
and maintenance are the responsibility of the land user. If pines are the species of choice for re-planting, the cost
is considerably more than that shown above (which relates to poplar and willow).
Assuming: shelterbelts of 600 m by 400 m; each strip has 5 lines of trees (3 m apart), 2 m between trees within lines: resulting in 104 trees/ha, including the cropland between the strips (density within strips is 1666 trees/ha). Labour for establishment (104 trees): Land preparation, planting 10 days and 15 days for watering, weeding, etc (for first 3 years).
4.8 Most important factors affecting the costs
Describe the most determinate factors affecting the costs:
The most important factors to affect the costs are seedlings (No.) and machine.
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
Specify average annual rainfall (if known), in mm:
430.00
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%)
Landforms:
- 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.
Indicate if the Technology is specifically applied in:
- not relevant
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):
- coarse/ light (sandy)
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: low -medium
Soil drainage / infiltration: good
Soil water storage capacity: medium
5.6 Characteristics of land users applying the Technology
Market orientation of production system:
- mixed (subsistence/ commercial
Off-farm income:
- 10-50% of all income
Relative level of wealth:
- average
Level of mechanization:
- mechanized/ motorized
Indicate other relevant characteristics of the land users:
Population density: 10-50 persons/km2
Annual population growth: 1% - 2%
80% of the land users are average wealthy and own 35% of the land.
Off-farm income specification: farmers benefit from the shelterbelts as a source of off-farm income, through fodder, timber and firewood
5.7 Average area of land owned or leased 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
- communal/state
- individual (see Annex T3 for remark)
- individual (see Annex T3 for remark)
6. Impacts and concluding statements
6.1 On-site impacts the Technology has shown
Socio-economic impacts
Production
crop production
wood production
production area
Comments/ specify:
width of the shelterbelt
Income and costs
farm income
Other socio-economic impacts
off-farm income
Comments/ specify:
extra timber and firewood
Crop production
Comments/ specify:
Trees in competition with crops for solar radiation, fertilizer, and water
Socio-cultural impacts
conflict mitigation
Loss of Food per agricultural land
Comments/ specify:
shelterbelts of trees are not a direct source of food
Ecological impacts
Water cycle/ runoff
surface runoff
Quantity before SLM:
8
Quantity after SLM:
0
Soil
soil moisture
soil cover
soil loss
Quantity before SLM:
4
Quantity after SLM:
2
Climate and disaster risk reduction
wind velocity
Other ecological impacts
sand encroachment
microclimate for crops
Comments/ specify:
regulating temperature, increasing humidity
conservation/maintenance of soil fertility
6.4 Cost-benefit analysis
How do the benefits compare with the maintenance/ recurrent costs (from land users' perspective)?
Short-term returns:
slightly positive
Long-term returns:
very positive
6.5 Adoption of the Technology
- single cases/ experimental
If available, quantify (no. of households and/ or area covered):
40 households in an area of 100-1000km^2 (10-50 persons/km^2)
Of all those who have adopted the Technology, how many have did so spontaneously, i.e. without receiving any material incentives/ payments?
- 0-10%
Comments:
100% of land user families have adopted the Technology with external material support
40 land user families have adopted the Technology with external material support
Comments on acceptance with external material support: estimates
Comments on spontaneous adoption: estimates
There is no trend towards spontaneous adoption of the Technology
Comments on adoption trend: The technology has not spontaneously spread beyond the areas developed through government intervention.
6.7 Strengths/ advantages/ opportunities of the Technology
Strengths/ advantages/ opportunities in the compiler’s or other key resource person’s view |
---|
Reduced wind speed and trapped wind-blown sand particle How can they be sustained / enhanced? Combine deciduous and evergreen trees to maintain shelterbelt’s protective function throughtout the year. |
Increased crop yield How can they be sustained / enhanced? Extend shelterbelt technology to unprotected croplands. |
Increased cash income How can they be sustained / enhanced? Improve rotational felling regimes that maximise quantity and quality of tree products (timber; fruit etc) without reducing the shelterbelt’s protective function. In Inner Mongolia apricot (Prunus armeniaca) and sea buckthorn (Hippophae rhamnoides) and in Gansu Province the Chinese dates (Ziziphus jujuba) are increasingly used. |
Apart from their effect on the wind, the overall benefits of the shelterbelts - for timber, firewood, fruits and fodder for animals - outweigh the loss of cropland occupied by trees How can they be sustained / enhanced? Experience over 40 years has demonstrated that narrower trees strips and smaller grid size (100 by 200 m) would increase ecological efficiency, but due to higher costs and potential competition with crops, the spacing of the shelterbelts has mostly remained as it was originally. |
From 1960 onwards, approximately 22 million hectares – of vulnerable cropland have been protected in eastern Inner Mongolia Editors’ comments: In China, a total of 1.84 million km2 suffer from desertification related to sand storms, shifting sands and wind erosion, making up 19% of the total land area. In those dry and desertified zones, farmland is barely productive, even with irrigation. The construction of shelterbelts in this northeastern part of China has had multiple benefits that outweigh the loss of cropland. However, maintenance has become an important issue with the changes in China’s land use laws. This is one of two examples of windbreaks amongst the case studies in this book. Remark: In the 1960s, all land ownership and land use rights in China were communal and cropland was farmed collectively by village communes. After reform and open policy was put into practice in 1978, land use rights were transferred to the villages, to groups and individuals. Land itself and the shelterbelts however still belonged to the state. Nowadays the rights to cultivate specific parcels of land, within protected blocks, are generally granted to individual farm households. In some cases, in recent years, the shelterbelts too have been redistributed to individuals to look after. Inevitably maintenance has become an issue. But most of the shelterbelts are managed well. 3.2.8: If farmer cuts mature timber (for example a 40 year-old poplar), he/she can sell it for US$ 20–25 per tree. With maturity of shelterbelts, the timber production increases, which brings increasing economic benefits; meanwhile, the effect of protection from wind erosion also improves. |
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? |
---|---|
Loss of land due to area used for the shelterbelts | In this wind-prone part of Inner Mongolia, overall gains from the protected zones compensate for the reduced area under crops, especially if economically valuable species are planted in the shelterbelt, such as Caragana korshinskii, which can be used as forage, for 'green fertilizer' through leaf mulch and for firewood. |
Competition for sunshine, fertilizer and water | Pruning of branches and digging of ditches to prevent roots penetrating the adjacent cropland |
Farmers lost the right to crop the tree-occupied land (since the shelterbelts belonged to the state). Originally, farmers were not allowed to fell trees | Nowadays the local forestry department permits farmers to occasionally cut trees, which is a source of income. If land users were allowed to cut trees on a more systematic basis, it would help them to better appreciate the benefits. |
High cost (labour and money) for establishment | Government support required. |
Shelterbelts comprised of single tree species are less resistant to pests and diseases Shelterbelts consume more water |
Combine trees and shrubs/ different species, which improves both resistance and also the protective effect. But they also help in drainage (where this is a problem) through lowering the ground water table and simultaneously reducing salinity. Appropriate tree species need to be selected and bred. |
7. References and links
7.2 References to available publications
Title, author, year, ISBN:
China atlas. China atlas publishing house, P 52.. 1999.
Available from where? Costs?
library of Department of Resource and Environmental Science, BNU.
Title, author, year, ISBN:
Zhao Yu, Jing Zhengping, Shi Peijun, Hao Yunchong et al. Inner Mongolia soil erosion research remote sensing was used in Inner Mongolia soil erosion research, Science publishing house, P25.. 1989.
Available from where? Costs?
library of Department of Resource and Environmental Science, BNU.
Title, author, year, ISBN:
Inner Mongolia forest department, Forest work manual,12, P33-34, P67.. 1998.
Available from where? Costs?
library of Department of Resource and Environmental Science, BNU.
Title, author, year, ISBN:
Synthesized investigate team in Inner Mongolia-Ningxia, CAS. West of northeast Forest in Inner Mongolia autonomy region, Science publishing house, P82-101.. 1981.
Available from where? Costs?
library of Department of Resource and Environmental Science, BNU.
Title, author, year, ISBN:
Sun Jinzhu. Natural condition and reconstruct in Hetao plain, Inner Mongolia people' s publishing house, P188-189.. 1976.
Available from where? Costs?
library of Department of Resource and Environmental Science, BNU.
Title, author, year, ISBN:
Inner Mongolia forest Department. Inner Mongolia autonomy region forest statistic data,P75.. 1987.
Available from where? Costs?
library of Department of Resource and Environmental Science, BNU.
Title, author, year, ISBN:
Hu Chun(chief editor). Inner Mongolia autonomy region climate resources about agriculture, forest and animal husbandry, Inner Mongolia people's publishing house, P45-47.. 1984.
Available from where? Costs?
library of Department of Resource and Environmental Science, BNU.
Title, author, year, ISBN:
Water and soil conservation bureau, Yellow River irrigation works committee of Department of water and electricity. Water and soil conservation economy benefit thesis collecting, P45-47.. 1987.
Available from where? Costs?
library of Department of Resource and Environmental Science, BNU.
Title, author, year, ISBN:
Zhang Pangchuen, A study on the benefit of shelter belt in the south part of Kerqin sand to agriculture increase in production. Journal of arid land resource and environment. Vol.4, no.1, P11-87.. 1990.
Available from where? Costs?
library of Department of Resource and Environmental Science, BNU.
Title, author, year, ISBN:
Sun Jinzhu,Chen Shan(chief editor). Inner Mongolia environment alarm beforehand and repair countermeasure. Inner Mongolia people's publishing house, P132.. 1994.
Available from where? Costs?
library of Department of Resource and Environmental Science, BNU.
Title, author, year, ISBN:
Compilation Committee of Inner Mongolia Forest Inner Mongolia Forest, Beijing: China Forestry Publishing House, 1989,299–319. 1989.
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Shelter Belt [China]
The shelter belt is a strip or a row of trees planted in a farmland as a wind barrier to protect crops and reduce wind erosion.
- Compiler: Meili WEN
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