Technologies

Compost application on rice fields [Cambodia]

ការប្រើប្រាស់ជីកំប៉ុស្តិ៏នៅក្នុងស្រែ (Khmer)

technologies_1218 - Cambodia

Completeness: 82%

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:
SLM specialist:

Khonhel Pith

Local Agricultural Research and Extension Centre LAREC

Cambodia

SLM specialist:

Mesa Say

Society for Community Development in Cambodia SOFDEC

Cambodia

SLM specialist:

Sreytouch Bin

Society for Community Development in Cambodia SOFDEC

Cambodia

Name of the institution(s) which facilitated the documentation/ evaluation of the Technology (if relevant)
CDE Centre for Development and Environment (CDE Centre for Development and Environment) - Switzerland

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

1.5 Reference to Questionnaire(s) on SLM Approaches (documented using WOCAT)

Model farmer
approaches

Model farmer [Cambodia]

Model farms were introduced by a NGO in order to spread knowledge about SLM (compost, System of Rice Intensification SRI, and other technologies) in the project area.

  • Compiler: Christoph Kaufmann

2. Description of the SLM Technology

2.1 Short description of the Technology

Definition of the Technology:

Manure, leaves and rice straw are gathered in a compost house and the produced compost is applied twice a year to the rice field.

2.2 Detailed description of the Technology

Description:

Compost is produced in compost houses and is seen as a good and easy soil amendment. It is produced by mixing organic components (in this case study cow manure, rice straw, different leaves and ash) which are locally available. The ideal mix of ingredients shows an N-to-C ratio of approximately 1 to 25. By adding compost to the topsoil, its humus content is increased, and therefore the soil fertility and water holding capacity are enhanced. Although the technology can be applied with little technological knowledge, the land user’s workload is augmented. This can be detrimental in a human environment with constantly decreasing available labour force.

The purposes of compost production are multifaceted. From the land user’s point of view, the increased yields are certainly one of the most determining factors. This is due to the augmentation of organic matter and nutrients in the topsoil which results in a higher soil fertility. Therefore, the use of chemical fertilizer can be diminished while the yields stay the same. This results in the amelioration of the land user’s livelihood, since he needs to buy less fertilizer. Also, the improved soil structure (according to the land user, the soil is softer and easier to cultivate) and water retention capacity are of importance in this area, since the soils are sandy/loamy, and due to climate change the rainfall is more erratic and droughts more recurrent. Compost also buffers the soil’s pH and prevents acidification. As a consequence, the nutrient availability is increased. Finally, compost adds more biota to the soil.

First, the compost house is built. This can be done either with external inputs such as bricks, cement, and a tin roof (the initial investment is higher, but the recurrent maintenance activities lower), or with locally available, natural inputs such as rice straw and clay for the walls and dried sugar palm leaves for the roof (the initial investment is lower, however there are more recurrent maintenance activities which can be detrimental for the continuation of compost production).
Once the compost house is built, the organic matter (approximately 70 % cow manure, and 30 % rice straw and different leaves, with a small amount of ash) is collected in the surroundings and carried to the compost house. In this case study, compost is produced once during the dry season and once during the wet season. During the dry season, water is added to the organic matter in order to facilitate the composting process. Ideally, the organic matter should be turned in order to guarantee a complete composting process. However, this includes a rather big workload. As a result, turning is not always practiced in the area (high migration rates result in a decrease of available labour force).
When the composting process is completed, the compost is carried to the fields with the use of animal traction. This is done several times: once when the fields are plowed, once when the rice seedlings are transplanted and once while the rice is growing (“top dressing”).

The analyzed area is flat (slope < 2%), with a tropical climate with a (dry and a wet season), and the soils are mostly sandy or loamy. The soils have a low fertility, contain little organic matter, the pH is sinking, the area has been deforested a long time ago and the groundwater table is rather high (1-2 m during the dry season, on the surface during wet season).
Due to climate change, land users notice more erratic rainfalls, temperatures rise and more recurrent droughts. Rice is the predominant crop grown in the area, since it serves as staple food (mix subsistence and commercial activities). Rice is often grown in monocultures and harvested once a year. Once the rice is harvested (dry season), the cattle are released to the paddy fields.

As an addition to rice, most land users grow vegetable and fruits in small home gardens (subsistence) and complement their income by producing handicrafts or through off farm income / remittances from family members working in other places. The increasing migration rate (the young generation leaves the villages to work in the cities, garment industry or abroad) results in a decrease of available labour force in the area. This has detrimental effects on the agricultural activities. Furthermore, the civil war in the 1970s (Khmer Rouge) led to the loss of agricultural knowledge.

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:

Cambodia

Region/ State/ Province:

Kampong Chhnang

Further specification of location:

Rolear Pha-er

Specify the spread of the Technology:
  • evenly spread over an area
If precise area is not known, indicate approximate area covered:
  • 10-100 km2

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:
  • through projects/ external interventions
Comments (type of project, etc.):

A local NGO provided a training on compost making, about 5 years ago.

3. Classification of the SLM Technology

3.1 Main purpose(s) of the Technology

  • reduce, prevent, restore land degradation
  • reduce risk of disasters

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

Land use mixed within the same land unit:

Ja

Specify mixed land use (crops/ grazing/ trees):
  • Agro-pastoralism (incl. integrated crop-livestock)

Cropland

Cropland

  • Annual cropping
Annual cropping - Specify crops:
  • cereals - rice (wetland)
Number of growing seasons per year:
  • 1
Specify:

Longest growing period in days: 210, Longest growing period from month to month: June - December

Grazing land

Grazing land

Animal type:
  • cattle - non-dairy beef
  • cattle - non-dairy working
Comments:

Major land use problems (compiler’s opinion): Lack of organic matter, lack of water retention in soil, irregularity of rainfall, low soil fertility (sandy soil), monocultures, bare soil during dry season, ploughing.
Major land use problems (land users’ perception): Rice field: lack of nutrients, need fertilizer and compost otherwise no good yield. Not enough compost available, need to use also small amount of chemical fertilizer even though compost is applied. Lack of water. Soil erosion.

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

  • improved ground/ vegetation cover

3.6 SLM measures comprising the Technology

agronomic measures

agronomic measures

  • A2: Organic matter/ soil fertility
  • A3: Soil surface treatment

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)
  • Ca: acidification
biological degradation

biological degradation

  • Bl: loss of soil life
Comments:

Main causes of degradation: soil management (Ploughing, soil is left bare for several weeks), crop management (annual, perennial, tree/shrub) (Rice monoculture (rice serves as staple food)), change of seasonal rainfall (More erratic beginning of wet season), droughts (On dry soil, rice cannot be planted and if already planted, rice cannot grow), labour availability (High migration rates from the villages to garment industry, cities or abroad, influences agricultural activities (e.g. broadcasting instead of transplanting of rice seedlings)), education, access to knowledge and support services (Khmer Rouge regime in the 1970s, a lot of knowledge got lost.)
Secondary causes of degradation: over-exploitation of vegetation for domestic use (Rice straw is removed for different domestic uses (cattle, mushroom cultivation, etc.)), overgrazing (Cattle eats rice straw left after harvest, less organic matter on the field, grazing is not managed.), change in temperature, Heavy / extreme rainfall (intensity/amounts), land tenure (Some incidents of land grabbing, land use rights not clear), poverty / wealth

3.8 Prevention, reduction, or restoration of land degradation

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

Manure, straw, ash and leaves are gathered in a compost hut, and later on dispersed on the paddy fields.
Kampong Chhnang

Technical knowledge required for field staff / advisors: moderate
Technical knowledge required for land users: low (It is not difficult to make compost, however it increases the workload of the land user. This might lead to the adaptation of the Technologies in order to decrease the additional workload.)
Main technical functions: increase in organic matter, increase in nutrient availability (supply, recycling,…)
Secondary technical functions: increase / maintain water stored in soil

Manure / compost / residues
Material/ species: Cow manure, mango leaves, rice straw, wood ash, green plants.
Quantity/ density: 3.7 t/ha
Remarks: 1 part at the beginning of the rainy season (rice transplantation), 1 part during the growing period

Author:

Stefan Graf

4.2 General information regarding the calculation of inputs and costs

Specify currency used for cost calculations:
  • USD
Indicate average wage cost of hired labour per day:

5.00

4.3 Establishment activities

Activity Timing (season)
1. Construction of compost house
2. Clay: Dig pit (10 cm) and add clay from the rice field
3. Bricks and cement: make brick walls
4. iron roof
5. poles
6. nails
7. labour

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 labour 1.0 20.0 20.0 100.0
Construction material iron roof 1.0 15.0 15.0 100.0
Construction material bricks and cement 1.0 31.0 31.0 100.0
Construction material poles and nails 5.0 1.0 5.0 100.0
Total costs for establishment of the Technology 71.0
Total costs for establishment of the Technology in USD 71.0

4.5 Maintenance/ recurrent activities

Activity Timing/ frequency
1. Gather material for compost, prepares compost and adds water in dry season all year round
2. Bring compost to fields June - September

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 labour 1.0 140.0 140.0 100.0
Total costs for maintenance of the Technology 140.0
Total costs for maintenance of the Technology in USD 140.0
Comments:

Machinery/ tools: Please note that the interviewed land user owns cows that are used for bringing the compost to the field. Hence, the costs for animal traction in this case study are zero.
1 compost house, around 4m^3.

4.7 Most important factors affecting the costs

Describe the most determinate factors affecting the costs:

Cost are affected by the availability of material to build the compost house (bricks, roof, etc.), which can be used long term.
Locally available, free material (sugar palm leaves for the roof, straw and clay for the walls) can be used as well, but it decays more quickly than the material used in this case-study (more recurrent maintenance activities).
The transport of manure to the fields is also an important expense. It is often done with the ox carts. As nearly all families owning oxen have a cart for different uses (firewood and product transportation), it is difficult to calculate this 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

Thermal climate class: tropics. 27°C to 35°C

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.

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)
  • medium (loamy, silty)
Topsoil organic matter:
  • low (<1%)

5.4 Water availability and quality

Ground water table:

< 5 m

Availability of surface water:

medium

Water quality (untreated):

good drinking water

5.5 Biodiversity

Species diversity:
  • low

5.6 Characteristics of land users applying the Technology

Market orientation of production system:
  • subsistence (self-supply)
  • mixed (subsistence/ commercial)
Off-farm income:
  • 10-50% of all income
Relative level of wealth:
  • poor
  • average
Individuals or groups:
  • individual/ household
Gender:
  • women
  • men
Indicate other relevant characteristics of the land users:

Difference in the involvement of women and men: The application of compost depends mainly on the commitment of the land users – gender and level of wealth are not determinative. However, the work is divided between men and women (physical strength).
Population density: 10-50 persons/km2
Annual population growth: 0.5% - 1%
Off-farm income specification: The land user manufactures handicrafts that she sells. Also, one of her daughters works in the garment industry. In addition, she owns pigs and chicken she sells.

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:
  • state
  • individual, not titled
Land use rights:
  • individual
Water use rights:
  • open access (unorganized)

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
Comments/ specify:

The farmer uses less chemical fertilizer. The yields remain the same on the short term.

Income and costs

expenses on agricultural inputs

increased
decreased

workload

increased
decreased

Socio-cultural impacts

food security/ self-sufficiency

reduced
improved
Comments/ specify:

Less chemical fertilizer used

conflict mitigation

worsened
improved

contribution to human well-being

decreased
increased
Comments/ specify:

Due to the use of compost, land users are less dependent on chemical fertilizers. Therefore, the cost of production decreases while the income remains the same.

Ecological impacts

Soil

nutrient cycling/ recharge

decreased
increased

soil organic matter/ below ground C

decreased
increased

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

6.4 Cost-benefit analysis

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

neutral/ balanced

Long-term returns:

positive

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

neutral/ balanced

Long-term returns:

positive

6.5 Adoption of the Technology

  • 11-50%
If available, quantify (no. of households and/ or area covered):

15% of land user families have adopted the Technology with external material support 20 land user families have adopted the Technology with external material support

Of all those who have adopted the Technology, how many did so spontaneously, i.e. without receiving any material incentives/ payments?
  • 51-90%
Comments:

Comments on acceptance with external material support: The technology was first introduced by a training (20 people attended), and then the neighbors of these farmers copied it. For each farmer trained, approximately 5 neighbors copied the technology.
85% of land user families have adopted the Technology without any external material support
130 land user families have adopted the Technology without any external material support
There is no trend towards spontaneous adoption of the Technology. Compost making increases the workload of the land users an that impedes the spontaneous adoption of the Technology.

6.7 Strengths/ advantages/ opportunities of the Technology

Strengths/ advantages/ opportunities in the land user’s view
Less chemical fertilizer is used for the same yield, so the farmer can save money since she buys less chemical fertilizer.
Soil fertility is better. She sees more earthworms in the fields.
Ploughing became easier, because the soil is less hard after compost application.
Strengths/ advantages/ opportunities in the compiler’s or other key resource person’s view
Low cost, locally available and effective fertilizer/soil improving material.
Soil quality (organic matter, nutrient content, water retention, soil biota) is improved
The resilience is increased; farmers are less dependent on external inputs (fertilizer…)
Long term increased yields.

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?
The collection of the material and the preparation of the compost (turning) is time consuming. Monitoring the cost/benefit ratio to show the benefit to the farmer
It is difficult to transport the compost to the field. Collaboration between neighbors to lower costs of hiring someone or lending machines.
She cannot make enough compost for all the fields Work toward an integrated production.
Weaknesses/ disadvantages/ risks in the compiler’s or other key resource person’s view How can they be overcome?
Not enough organic matter to make enough compost (number of cattle is low, rice monoculture). Work toward an integrated production.
Increased workload while labour availability is decreasing due to migration. Increase the handicraft work on the farms. Diversification of the production with less labour intensive species.
Low motivation of the land user because the composting work has to be done each year again. Monitoring to show the long-term cost/benefit ratio.
The composting process is not completely understood; weed and rice seeds survive and are growing on the fields. Explanations about seed survival and dormancy to explain the purpose of composting.

7. References and links

7.1 Methods/ sources of information

  • field visits, field surveys
  • interviews with land users
When were the data compiled (in the field)?

23/06/2014

7.2 References to available publications

Title, author, year, ISBN:

Society for Community Development in Cambodia SOFDEC

Available from where? Costs?

www.sofdec.org

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