Technologies

Soil Conservation Through Bench Terrace Technology in Highly Degradable Hilly Slopy Areas of Bangladesh [Bangladesh]

"Dhap Poddoti" for soil erosion control in the highly degradable Chattagram Hill tract area of Bangladesh

technologies_4284 - Bangladesh

Completeness: 92%

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)

Compiler:
SLM specialist:

Islam Mahabubul

Soil Resource Development Institute

Bangladesh

land user:

Chakma Ushalaya

Soil Resource Development Institute

Bangladesh

co-compiler:

Md Zahid Ameer

Soil Resource Development Institute

Bangladesh

Name of the institution(s) which facilitated the documentation/ evaluation of the Technology (if relevant)
Soil Resource Development Institute (SRDI) (Soil Resource Development Institute (SRDI)) - Bangladesh

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:

Ja

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?

Geen

Comments:

It is a very effective technology for soil conservation in hilly areas.

2. Description of the SLM Technology

2.1 Short description of the Technology

Definition of the Technology:

Bench terraces are a soil and water conservation measure used on sloping land with relatively deep soils to retain water and control erosion. They are normally constructed by cutting and filling to produce a series of level steps or benches. This allows water to infiltrate slowly into the soil. Bench terraces are reinforced by banks of soil or stone that block waterflow above the forward edges. This practice is typical for rice-based cropping systems.It is also helpful to increase the beauty of the land along with increasing the soil stability on these lands.

2.2 Detailed description of the Technology

Description:

The Chittagong Hill Tracts (CHT) are undergoing deforestation and land degradation arising from environmentally unsuitable activities such as tobacco cultivation in sloping land, shifting cultivation and logging. Shifting cultivation, also known as slash-and-burn agriculture. The present shifting cultivation system with short fallow in the Chittagong Hill Tracts has accelerated erosion, land degradation, deforestation, and impoverishment of tribal people in CHT. If the present state of degradation continues, most of the areas under shifting cultivation will be severely degraded and future generations will face more difficulties to eke out their livelihoods on further degraded land. That land shows massive erosion impact as influenced by shifting cultivation (Jhum) at steep and continuously sloping lands.

To address the aforesaid constraints in hilly areas of CHT, the Soil Conservation and Watershed Management Centre (SCWMC) of the Soil Resource Development Institute (SRDI) has developed the "Bench Terrace" technology. In this technology, some bench like terraces are made on the slopy land of hills where the slope angle is more than 30 degree. The width of the terraces ranges from 2.5 to 3.0 metre. The height of the terraces is 0.6 metre to 1 metre. An embankment constructed at the outer rim of the terraces prevents run off and soil loss over the outer edge of the terrace during heavy rain in the monsoon. The length of such terraces depends on the topographical contexts within which the terraces are constructed. The technology has various benefits:

- To reduce the quantum of overland flow/sheet flow or runoff, and their velocity.
- To minimize the soil erosion.
- To conserve soil moisture.
- To conserve soil fertility and to facilitate farming operations such as ploughing, irrigation etc. on sloping land.
- To promote intensive land use, permanent agriculture and checking shifting cultivation on steep lands.
- Bench terraces support proper water management and fertilizers/manure application. They will also help in increasing cropping intensity within a stable farming system.

The hill dwellers, who are the owners of the land, are practicing the technology because it has established a permanent solution for crop production instead shifting cultivation. The technology contributes to a reduction in land slides, soil erosion and to increased farm income. Bench Terraces are widely being used in the hilly areas of India, Nepal, Srilanka, Tamilnadu etc.


.

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:

Bangladesh

Region/ State/ Province:

Bandarban

Further specification of location:

Its a region

Specify the spread of the Technology:
  • evenly spread over an area
If precise area is not known, indicate approximate area covered:
  • 10-100 km2
Is/are the technology site(s) located in a permanently protected area?

Geen

Comments:

This area is not under reserve forest area of Bangladesh forest department, instead it includes shifting cultivation areas of hill dwellers.

2.6 Date of implementation

If precise year is not known, indicate approximate date:
  • less than 10 years ago (recently)

2.7 Introduction of the Technology

Specify how the Technology was introduced:
  • during experiments/ research
Comments (type of project, etc.):

Soil conservation and watershed management centre of soil resource development institute(SRDI) has developed the technology through long term research trial in farmers field as well as in research station.

3. Classification of the SLM Technology

3.1 Main purpose(s) of the Technology

  • improve production
  • reduce, prevent, restore land degradation
  • conserve ecosystem
  • protect a watershed/ downstream areas – in combination with other Technologies
  • reduce risk of disasters
  • create beneficial economic impact

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

Land use mixed within the same land unit:

Geen


Forest/ woodlands

Forest/ woodlands

  • (Semi-)natural forests/ woodlands
(Semi-)natural forests/ woodlands: Specify management type:
  • Shifting cultivation
  • Non-wood forest use
Are the trees specified above deciduous or evergreen?
  • mixed deciduous/ evergreen
Products and services:
  • Fuelwood

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:

Ja

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

Cropland

  • Annual cropping
  • Tree and shrub cropping
Annual cropping - Specify crops:
  • vegetables - leafy vegetables (salads, cabbage, spinach, other)
Annual cropping system:

Continuous vegetables

Tree and shrub cropping - Specify crops:
  • citrus
Is intercropping practiced?

Geen

Is crop rotation practiced?

Geen

Comments:

The land management and production system contains 3 cropping seasons per annum. The seasons are Rabi- Kharif1-Kharif-2.

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
  • minimal soil disturbance
  • cross-slope measure

3.6 SLM measures comprising the Technology

structural measures

structural measures

  • S1: Terraces

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
  • Wg: gully erosion/ gullying

3.8 Prevention, reduction, or restoration of land degradation

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

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

4.1 Technical drawing of the Technology

Technical specifications (related to technical drawing):

According to the hill slope, the height, width (depth) and length of terrace can vary. Generally the width (depth) of a terrace is 2.5- 3 metre, the height is 1 metre and slope angle 10 to 15 degree. The contour is established by uplifting soil in a straight line and the wall is constructed by mud. The floor area is leveled and cultivated with spade or plough. Generally the floor area of a bench terrace is 40 square metres. An access path is kept open from one corner of the terrace.
The horizontal orientation of the terraces follow the contour line of the slope. That contour line is an imaginary line perpendicular to the sloping direction (uphill to downhill) of an area. The contour line runs horizontally along the slope of a farm.

Viewed from an opposite the face of the slope, all contour lines will appear horizontally. However, viewed from uphill, the lines may either be straight, curved like the outside of a sphere, or curved irregularly downward or upward depending on the presence of low- and high-lying surfaces on the face of the slope.

4.2 General information regarding the calculation of inputs and costs

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

1 acre

other/ national currency (specify):

Taka( Bangladeshi currency)

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

80.0

Indicate average wage cost of hired labour per day:

500 taka

4.3 Establishment activities

Activity Timing (season)
1. Cleaning forest Before making the terraces
2. Earth cutting Before raining season
3. Making terraces
4. Land preparation every season
5. fertiliser application every season
6. seed sowing every season
7. Irrigation 5 times per cropping season
8. Intercultural operation occassionally
9. Reconstruction of terraces Before rainy season

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 Cleaning forest persons-per day 5.0 500.0 2500.0 100.0
Labour Earth cutting persons-per day 4.0 500.0 2000.0 100.0
Labour Making terraces persons-per day 5.0 500.0 2500.0 100.0
Labour Land preparation persons-per day 3.0 500.0 1500.0 100.0
Equipment fertiliser application persons-per day 1.0 500.0 500.0 50.0
Equipment seed sowing persons-per day 2.0 500.0 1000.0 30.0
Equipment Irrigation persons-per day 3.0 500.0 1500.0 70.0
Equipment Intercultural operation persons-per day 4.0 500.0 2000.0 100.0
Equipment Machine operated cleaning tools Number 1.0 4000.0 4000.0 50.0
Equipment spade Number 5.0 300.0 1500.0 100.0
Equipment mower Number 1.0 2000.0 2000.0 100.0
Equipment sickle Number 5.0 200.0 1000.0 100.0
Plant material Tape Piece 2.0 100.0 200.0 100.0
Plant material rope piece 2.0 50.0 100.0 100.0
Plant material seed Kg 0.5 300.0 150.0
Plant material seedlings Number 50.0 50.0 2500.0
Fertilizers and biocides Nitrogen Kg 20.0 16.0 320.0 70.0
Fertilizers and biocides Phosphorus Kg 10.0 22.0 220.0 70.0
Fertilizers and biocides potassium Kg 15.0 30.0 450.0 70.0
Fertilizers and biocides Compost Ton 1.0 1000.0 1000.0 100.0
Construction material pesticide Kg 0.5 200.0 100.0 50.0
Construction material pipes Number 5.0 400.0 2000.0 50.0
Total costs for establishment of the Technology 29040.0
Total costs for establishment of the Technology in USD 363.0
If land user bore less than 100% of costs, indicate who covered the remaining costs:

Department of Agriculture Extension and other Government and non Government organisation

Comments:

The Government organisations always encourage the land owners to practice the technology by giving a portion of inputs.

4.5 Maintenance/ recurrent activities

Activity Timing/ frequency
1. Reconstruction of terraces Before rainy season

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 Reconstruction of terraces Persons-per day 2.0 500.0 1000.0 80.0
Total costs for maintenance of the Technology 1000.0
Total costs for maintenance of the Technology in USD 12.5

4.7 Most important factors affecting the costs

Describe the most determinate factors affecting the costs:

Labour cost is the most important factor that affects the total cost.

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
  • sub-humid

Mean annual temperature 27 degree celcius

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):
  • medium (loamy, silty)
Soil texture (> 20 cm below surface):
  • medium (loamy, silty)
Topsoil organic matter:
  • low (<1%)
If available, attach full soil description or specify the available information, e.g. soil type, soil PH/ acidity, Cation Exchange Capacity, nitrogen, salinity etc.

soils are clay loam to clay, soils are acidic in nature, nitrogen content in most cases low and presence of no salinity. Land type -very high

5.4 Water availability and quality

Ground water table:

> 50 m

Availability of surface water:

poor/ none

Water quality (untreated):

poor drinking water (treatment required)

Water quality refers to:

ground water

Is water salinity a problem?

Geen

Is flooding of the area occurring?

Geen

5.5 Biodiversity

Species diversity:
  • medium
Habitat diversity:
  • medium

5.6 Characteristics of land users applying the Technology

Sedentary or nomadic:
  • Sedentary
Market orientation of production system:
  • subsistence (self-supply)
Off-farm income:
  • 10-50% of all income
Relative level of wealth:
  • average
Individuals or groups:
  • individual/ household
Level of mechanization:
  • manual work
Gender:
  • women
Age of land users:
  • middle-aged

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
Water use rights:
  • open access (unorganized)
Are land use rights based on a traditional legal system?

Ja

5.9 Access to services and infrastructure

health:
  • poor
  • moderate
  • good
education:
  • poor
  • moderate
  • good
technical assistance:
  • poor
  • moderate
  • good
employment (e.g. off-farm):
  • poor
  • moderate
  • good
markets:
  • poor
  • moderate
  • good
energy:
  • poor
  • moderate
  • good
roads and transport:
  • poor
  • moderate
  • good
drinking water and sanitation:
  • poor
  • moderate
  • good
financial services:
  • poor
  • moderate
  • good

6. Impacts and concluding statements

6.1 On-site impacts the Technology has shown

Socio-economic impacts

Production

crop production

decreased
increased

risk of production failure

increased
decreased

production area

decreased
increased

land management

hindered
simplified
Comments/ specify:

In hilly area , due to slopy land , it is difficult to manage because soil erosion is higher in rainy season, there are no structures to reduce soil erosion. But, due to the establishment of bench terraces, soil erosion in rainy season is significantly checked and long slopy stretches are interupted by a soil stabilising structure. In this way , land management is simplified.

Income and costs

expenses on agricultural inputs

increased
decreased

farm income

decreased
increased

diversity of income sources

decreased
increased

economic disparities

increased
decreased

workload

increased
decreased

Socio-cultural impacts

food security/ self-sufficiency

reduced
improved

health situation

worsened
improved

land use/ water rights

worsened
improved

cultural opportunities

reduced
improved

recreational opportunities

reduced
improved
Comments/ specify:

As the economic situation is improved through increased crop production due to this method, the land owners will beneift from new opportunities for recreational programmes.

community institutions

weakened
strengthened

national institutions

weakened
strengthened

SLM/ land degradation knowledge

reduced
improved

conflict mitigation

worsened
improved

situation of socially and economically disadvantaged groups

worsened
improved

Ecological impacts

Soil

soil moisture

decreased
increased

soil cover

reduced
improved

soil loss

increased
decreased

soil accumulation

decreased
increased

nutrient cycling/ recharge

decreased
increased

soil organic matter/ below ground C

decreased
increased

acidity

increased
reduced
Comments/ specify:

As the land owners use balanced fertiliser , with proper irrigation and other intercultural operations, so, soil acidity will reduce a little bit.

Biodiversity: vegetation, animals

Vegetation cover

decreased
increased

biomass/ above ground C

decreased
increased

plant diversity

decreased
increased

animal diversity

decreased
increased
Comments/ specify:

As planned cropping system is going to be established in bench terrace land management system, so soil flora and fauna will get a suitable environment to grow.

beneficial species

decreased
increased

habitat diversity

decreased
increased

pest/ disease control

decreased
increased
Climate and disaster risk reduction

landslides/ debris flows

increased
decreased

drought impacts

increased
decreased

emission of carbon and greenhouse gases

increased
decreased
Comments/ specify:

In this production system, cropping intensity is increased 2-3 times and the crops are absorbing more CO2 for photosynthesis. So, carbon emission will reduce.

fire risk

increased
decreased

micro-climate

worsened
improved

6.2 Off-site impacts the Technology has shown

downstream siltation

increased
decreased

damage on neighbours' fields

increased
reduced

damage on public/ private infrastructure

increased
reduced

impact of greenhouse gases

increased
reduced
Comments/ specify:

In this production system, cropping intensity is increased 2-3 times and the crops are absorbing more co2 for photosynthesis. So, carbon emission will reduce.

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 moderately
seasonal temperature summer increase well
annual rainfall increase moderately
seasonal rainfall wet/ rainy season decrease moderately

Climate-related extremes (disasters)

Meteorological disasters
How does the Technology cope with it?
tropical storm moderately
local rainstorm well
local thunderstorm moderately
local hailstorm very well
local windstorm moderately
Climatological disasters
How does the Technology cope with it?
drought moderately
forest fire moderately
land fire well
Hydrological disasters
How does the Technology cope with it?
landslide very well
Biological disasters
How does the Technology cope with it?
insect/ worm infestation well

6.4 Cost-benefit analysis

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

positive

Long-term returns:

very positive

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

very positive

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?
  • 11-50%

6.6 Adaptation

Has the Technology been modified recently to adapt to changing conditions?

Geen

6.7 Strengths/ advantages/ opportunities of the Technology

Strengths/ advantages/ opportunities in the land user’s view
Risk of land slide reduced
Farm income increased
Strengths/ advantages/ opportunities in the compiler’s or other key resource person’s view
Soil erosion decreased
Crop production increased
Soil nutrient mining reduced
Soil nutrient availability enhanced
Soil moisture increased
Irrigation water use efficiency increased

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?
Labour cost very high Borrow money from financial institution
Weaknesses/ disadvantages/ risks in the compiler’s or other key resource person’s view How can they be overcome?
Lack of knowledge regarding land management in slopy hilly areas Take part in related training
Labour unavailability and labour cost is higher Engaged family members

7. References and links

7.1 Methods/ sources of information

  • field visits, field surveys

10

  • interviews with SLM specialists/ experts

10

  • compilation from reports and other existing documentation

5

When were the data compiled (in the field)?

16/04/2018

7.2 References to available publications

Title, author, year, ISBN:

Soil erosion in hilly areas affecting biodiversity and climate change and its biological conservation strategy,Md. Mijanur Rahman Wildlife Conservation Officer Coastal & Wetland Biodiversity Management Project Department of Environment, Teknaf, Cox’s Bazar

Available from where? Costs?

FAO, 1978. Soil erosion by water. FAO, United Nations. PP. 63-111 Khan, L.R. Watershed management. Field document no.44. UNDP/FAO/BGD/85/011. PP.151-193 Negi, S.S. 1983. Soil conservation. Fundamental of forestry volume.3. Rahman, M.M. 1994. A review paper on erosion control measures in hilly areas. FWT discipline, Khulna University, Khulna, Bangladesh Young, Anthony. 1989. Agro forestry for soil conservation. ICRAF.

Title, author, year, ISBN:

Soil erosion in the Chittagong hill tract and its impact on nutrient status of soils [in Bangladesh] [1992],Farid, A.T.M. Iqbal, A. Karim, Z.

Available from where? Costs?

AGRIS, FAO

7.3 Links to relevant online information

Title/ description:

A review of the effect of terracing on erosion,

URL:

https://www.researchgate.net/profile/Luuk_Dorren

7.4 General comments

The questionnaire should be more generalised so that all the land degradation specialists can fill up the document smoothly.

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