Crop rotation to promote safe vegetables [Cambodia]

Safe Vegetable

technologies_3165 - Cambodia

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)

land user:

Chanthou Ek



Vice Chief of Agricultral Extension Office of Provincial Department of Agriculture, Forestry and Fisheries, Kampong Chhnang Province:
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Chief of Agricultural Office of Tuek Phos District:
{'additional_translations': {}, 'value': 'Se Keo', 'user_id': '3619', 'unknown_user': False, 'template': 'raw'}
Vice Chief of Agronomy Office of Rolea B'ier District:

Bunleang Chhim

Office of Agricultural of Rolea B'ier District


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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:


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?



Farmer cultivate a variety of crops and change row destination.

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

A Safe Vegetable Growers Group in the Svaymeanchey Satrey Samaki Agricultural Cooperative

A Safe Vegetable Growers Group in the Svaymeanchey … [Cambodia]

The safe vegetable growers group was formed by farmers on a voluntary basis and is part of an Agricultural Cooperative. It supports the selling of products through an organized group to buyers. The producers and the buyers have to sign a contract as the main agreement and with set principles. …

  • Compiler: Navin Chea

2. Description of the SLM Technology

2.1 Short description of the Technology

Definition of the Technology:

Crop rotation is a component of integrated pest management (IPM) which can contribute to an improvement in crop production with a standardized and reduced use of chemical fertilizers and pesticides.

2.2 Detailed description of the Technology


Crop rotation is the process of regularly alternating crops on a seasonal basis on the same plot of land. One of the benefits is that nutrients and nitrogen will be transferred to the soil through this practice as traditionally green manure is added when crops are alternated with cereals. The practice helps to reduce the manifestation of diseases and insects that often occur when crop cultivation is repeated over a prolonged period. Crop rotation can improve the soil’s structure and fertility as different nutrients are absorbed from the soil, and the plants’ root systems are able to penetrate the soil at different depths (Cotheren J., 2014). Even though Cambodia has laws regarding the application of agricultural pesticides and fertilizers there are some farmers who still use them incorrectly. As an alternative, the intercropping technology can assist farmers in increasing yields and reduce crop damage by insects, whilst maintaining and improving the soil’s fertility through agronomy as well as biological measures.

Mrs. Ek Chantho decided to practice crop rotation for a whole year whilst at the same time reducing the use of chemical fertilizers and pesticides because this can help her to reduce expenses. A further advantage for her is being a member of the safe vegetable growers group, as her contract with REMIC guarantees her sales of her vegetables to the company. Additionally she is able to sell any surplus safe vegetables to other traders once she has fulfilled her contractual obligations with REMIC. The decision to practice crop rotation also helped to maintain and increase soil fertility as a little organic and semi-organic fertilizer is added instead of chemical fertilizers. Furthermore the amount of chemical pesticides has been reduced due to the practice of crop rotation.

In this case, long beans, luffa, winter melons, pumpkins and cucumbers were rotated on the plot. This practice helps to keep the soil fertile and the nutrients balanced as land degradation can result from the cultivation of the same crop, as it will repeatedly absorb the same nutrients. Furthermore, crop rotation also contributes to a reduction in plant diseases and prevents an increase in damage from pests as it prevents a particular crop from building up pathogens in the soil. Each farmer will grow two or three different crops at the same time and then will chose to grow other crops in the following season. However, as the choice of a farmer’s particular crop is coordinated by REMIC it ensures that each farmer in turn will assist in providing diversified crops to fulfil market demand.

The farmer stated that before practicing crop rotation, she mostly grew one or two crops which could be sold at a high price throughout the year. Therefore, in order to maintain her yields and prevent the crops from being damaged by insects she had to use a lot of chemical fertilizers and pesticides. However these only remained effective for a relatively short period and also increased her overheads. After having attended a course organized by Educational Concerns for Haiti Organization (ECHO), Rural Entrepreneurship & Market Inclusion in Cambodia (REMIC), and the Provincial Department of Agriculture she switched to crop rotation instead of cultivating one crop and to the use of organic and semi-organic fertilizers instead of chemicals. Furthermore her use of chemical pesticides also decreased as she followed standardized practices. This practice improves the soil quality, mitigates pests and diseases, reduces costs, improves income and also protects the health of producers and users.

As the farmers become highly efficient and the practice of crop rotation becomes sustainable they are able to improve their supply for the market. In fact, this has been successfully coordinated through REMIC’s planning and contracting which ensures that there is always an adequate supply of diversified vegetables. Moreover, ECHO collaborated to check the use of chemical fertilizers and control pesticides which managed to raise consumer confidence by ensuring there are safe vegetables for the market, which in turn allowed farmers to set a high price for their produce.

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:

Kampong Chhnang province

Further specification of location:

Samekki Mean Chey district, Svay commune, Kyang Tboung village

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):


If precise area is not known, indicate approximate area covered:
  • < 0.1 km2 (10 ha)

This technique is applied on the land of 50 x 40 m = 2000 square meters.

2.6 Date of implementation

Indicate year of implementation:


2.7 Introduction of the Technology

Specify how the Technology was introduced:
  • through projects/ external interventions
Comments (type of project, etc.):

ECHO organization

3. Classification of the SLM Technology

3.1 Main purpose(s) of the Technology

  • reduce, prevent, restore land degradation
  • create beneficial economic impact

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



  • Annual cropping
Annual cropping - Specify crops:
  • vegetables - melon, pumpkin, squash or gourd
  • legumes and pulses - beans
  • cucumber, luffa
Annual cropping system:

Vegetables - wheat/barley/oat/upland rice

Number of growing seasons per year:
  • 2

In April or May (planting long bean, luffa, and winter melon) and November or December (planting cucumbers and winter melon, but long bean is not cultivated because it attracts worms)

Is crop rotation practiced?


If yes, specify:

In April or May (planting long bean, luffa, and winter melon) and November or December (planting cucumbers and winter melon, but long bean is not cultivated because it attracts worms)


long bean, luffa, cucumber, winter melon

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)



It is plantation land, but there was not much of crops and no rotation either.

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

  • rotational systems (crop rotation, fallows, shifting cultivation)
  • integrated soil fertility management
  • integrated pest and disease management (incl. organic agriculture)

3.6 SLM measures comprising the Technology

agronomic measures

agronomic measures

  • A1: Vegetation/ soil cover
  • A2: Organic matter/ soil fertility

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)
physical soil deterioration

physical soil deterioration

  • Pc: compaction
  • Pu: loss of bio-productive function due to other activities
biological degradation

biological degradation

  • Bq: quantity/ biomass decline
  • Bp: increase of pests/ diseases, loss of predators

3.8 Prevention, reduction, or restoration of land degradation

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

Maintenance of soil nutrients and reduce the disease of crops by doing crop rotation with organic fertilizer and semi-organic fertilizer.

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

4.1 Technical drawing of the Technology

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Technical specifications (related to technical drawing):

The total land area of the plot where the farmer practices this technique is 50 meters x 40 meters. This is divided into the section for long beans which measures 50 meters x 17 meters, and within this area the beans are planted in eight parallel rows with a distance of one meter between each of the rows. Each of these rows contains two lines that are a distance of 0.6 meters apart. In each of the lines the long beans have been planted with a one meter gap between each of the clumps. It is not necessary for the farmer to create a ridge in each of the rows and so in order plant the beans she just has to dig a hole measuring 15 cm x 15 cm with a depth of 15 cm and then ensure that the seedlings are planted at a depth of about 3 cm. The section of land for planting the luffa measures 50 meters x 23 meters and within this area is direct seedlings in 9 parallel rows with a gap of two meters between each of the rows. In each of the rows there is a distance of 1.2 meters between each of the clumps and these can be planted in holes with the same dimensions as the long beans.


Mr. Khuon Sophal



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:

40 m X 50 m = 200 m2

other/ national currency (specify):


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


Indicate average wage cost of hired labour per day:

20000 Riel

4.3 Establishment activities

Activity Timing (season)
1. Plow and dry April
2. Digging hole April
3. Apply organic fertilizer and cow manure April
4. Seed cultivation April
5. Buy pumping mechine April

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 Plow and dry person-day 1.0 20000.0 20000.0 100.0
Labour Apply organic fertilizer and cow manure person-day 1.0 20000.0 20000.0 100.0
Labour Digging and cultivation person-day 5.0 20000.0 100000.0 100.0
Equipment Pumping machine piece 1.0 1200000.0 1200000.0 100.0
Equipment Two-wheel tractor piece 1.0 6000000.0 6000000.0 100.0
Plant material Long bean seeds package 4.0 8000.0 32000.0 100.0
Plant material Luffa seeds package 5.0 7000.0 35000.0 100.0
Fertilizers and biocides Organic fertilizer sack 1.0 130000.0 130000.0 100.0
Fertilizers and biocides Semi-organic fertilizer sack 1.0 130000.0 130000.0 100.0
Construction material Hoe piece 2.0 9000.0 18000.0 100.0
Construction material Soil basket piece 2.0 6000.0 12000.0 100.0
Construction material Trellising (using wood stick) piece 1000.0 250.0 250000.0 100.0
Total costs for establishment of the Technology 7947000.0
Total costs for establishment of the Technology in USD 1986.75

4.5 Maintenance/ recurrent activities

Activity Timing/ frequency
1. Watering In dry season every day and every week in rainy season
2. Weeding Every week
3. Trellising for long bean when 14-15 days old
4. Applied pesticide Since 20 days on is applied every 7-10 days
5. Pruning When 20-25 days old

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 Watering and weeding person-day 14.0 20000.0 280000.0 100.0
Labour Trellising person-day 3.0 20000.0 60000.0 100.0
Labour Apply pesticide person-day 6.0 20000.0 120000.0 100.0
Labour Pruning person-day 1.5 20000.0 30000.0 100.0
Total costs for maintenance of the Technology 490000.0
Total costs for maintenance of the Technology in USD 122.5

4.7 Most important factors affecting the costs

Describe the most determinate factors affecting the costs:

The costs of the two-wheel tractor is high.

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:


Specifications/ comments on rainfall:

The annual rainfall in 2015 was 1209 mm. In 2014 it was 1420.74 mm and in 2013 is was 1367.5 mm.

Indicate the name of the reference meteorological station considered:

Department of Meteorology, Ministry of Water Resources and Meteorology (2015)

Agro-climatic zone
  • sub-humid

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.
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:
  • 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.

Sandy-loam with pH=6.5, but don't know the precise depth of soil.

5.4 Water availability and quality

Ground water table:

on surface

Availability of surface water:


Water quality (untreated):

for agricultural use only (irrigation)

Is water salinity a problem?


Is flooding of the area occurring?




Comments and further specifications on water quality and quantity:

Occasionally, flooded from 7-10 days.

5.5 Biodiversity

Species diversity:
  • low
Habitat diversity:
  • low

5.6 Characteristics of land users applying the Technology

Sedentary or nomadic:
  • Sedentary
Market orientation of production system:
  • commercial/ market
Off-farm income:
  • > 50% of all income
Relative level of wealth:
  • average
Individuals or groups:
  • individual/ household
Level of mechanization:
  • mechanized/ motorized
  • 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, titled
Land use rights:
  • individual
Water use rights:
  • open access (unorganized)

Using water from river and stream.

5.9 Access to services and infrastructure

  • poor
  • moderate
  • good
  • poor
  • moderate
  • good
technical assistance:
  • poor
  • moderate
  • good
employment (e.g. off-farm):
  • poor
  • moderate
  • good
  • poor
  • moderate
  • good
  • 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


crop production

Comments/ specify:

Crop production increased due to crop rotation with using organic fertilizer and semi-organic fertilizer.

crop quality

Comments/ specify:

Crop quality is better because of using organic fertilizer instead of chemical fertilizer.

risk of production failure

Comments/ specify:

To cultivate more than one crop helps to reduce risk of production failure.

land management

Comments/ specify:

Changing crop varieties and location.

Income and costs

expenses on agricultural inputs

Comments/ specify:

Using chemical fertilizer is more expensive than organic fertilizer.

farm income

Comments/ specify:

Farm income increased because of reduced use of chemical fertilizer and cultivation of more than one crop.

Socio-cultural impacts

food security/ self-sufficiency

Comments/ specify:

Getting high production and good market because she can become part of the safe vegetable growers group.

health situation

Comments/ specify:

Health situation is improved due to changing from chemical fertilizer to organic fertilizer and semi-organic fertilizer.

SLM/ land degradation knowledge

Comments/ specify:

They were trained by Rural Entrepreneurship & Market Inclusion in Cambodia (REMIC), Educational Concerns for Haiti Organization (ECHO) and Provincial Department of Agriculture.

Ecological impacts

Water cycle/ runoff

water quality

Comments/ specify:

Due to reduced chemical fertilizers and pesticide application.


soil cover

Comments/ specify:

Cultivation of crops all years round, which does not cause erosion as well as maintain soil moisture.

soil crusting/ sealing

Comments/ specify:

When cultivation is all year round it helps to reduce evaporation that helps to reduce soil crusting.

soil compaction

Comments/ specify:

Organic and semi-organic fertilizers using prevent soil from compaction which is good for the crops' root.

nutrient cycling/ recharge

Comments/ specify:

Nutrient cycling is improved due to changing the varieties of crops.

Biodiversity: vegetation, animals

invasive alien species

Comments/ specify:

Armyworm, mealybug, and lady bug is reduced by crop rotation practice.

beneficial species

Comments/ specify:

Beneficial species is increased after change from chemical fertilizer and pesticide to organic and semi-organic fertilizer.

pest/ disease control

Comments/ specify:

Pest or disease control is increased by reducing amount of mealybug and armyworm through changing crop varieties.

6.2 Off-site impacts the Technology has shown

Specify assessment of off-site impacts (measurements):

There is no noticable negative impacts.

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 rainfall increase not known

6.4 Cost-benefit analysis

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


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


Long-term returns:

slightly positive

6.5 Adoption of the Technology

  • 1-10%
If available, quantify (no. of households and/ or area covered):

19 households

Of all those who have adopted the Technology, how many did so spontaneously, i.e. without receiving any material incentives/ payments?
  • 91-100%

Many farmers want to apply this technology because of high benefits.

6.6 Adaptation

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


6.7 Strengths/ advantages/ opportunities of the Technology

Strengths/ advantages/ opportunities in the land user’s view
A good market has been created for the crops because by joining the Svaymeanchey Satrey Samaki Agricultural Cooperative with the practice of crop rotation throughout the whole year that the farmers are able to provide a regular supply.
The reduction in the use of chemical fertilizers through the use of organic fertilizers and semi-organic fertilizers as well as the standardized use of chemical pesticides curtails the extension of negative impacts.
The soil’s nutrient content is balanced by not repeatedly cultivating one single crop on the same plot of land.
Fertilizers and pesticides are purchased from an officially authorized company.
Strengths/ advantages/ opportunities in the compiler’s or other key resource person’s view
A stable market has been created due to the Rural Entrepreneurship & Market Inclusion in Cambodia’s (REMIC) involvement as the buyer.
The farmers used to use a lot of chemical fertilizers on the land but now have switched to using organic and semi-organic fertilizers which they obtain from a licensed company. Moreover, chemical pesticides are used at the recommended level so that adverse impacts are avoided.
The vegetables are safe as they are being monitored by ECHO.
Crop rotation has improved the farmers’ economic returns as it has enabled them to cultivate throughout the year-round and plant a crop based on market demand.
The farmer has a clear understanding of sustainable land management through the practice of crop rotation with the limited use of chemical fertilizers and don’t use chemical pesticides with high toxin that adversely affect the soil, the environment, humans and animals which the ministry of Agriculture Forestry and Fishery has banned.
Besides using organic fertilizers and chemicals which have been purchased from an authorized company, the farmers now also use cow manure for their crops.

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?
Not yet adapted to climate change such as an increase in temperatures. Unsure
Limited knowledge of preventing the spread of insects and the use of natural fertilizers and botanical pesticides. Can gain experience through more crop cultivation
Weaknesses/ disadvantages/ risks in the compiler’s or other key resource person’s view How can they be overcome?
Lack of effective technology to mitigate the effects of climate change such as floods, droughts or an increase in temperatures. Need to check with planting schedule for the best time and need additional guidelines from relevant organizations as ECHO organization, who are responsible for monitoring and quality control as well as REMIC who is the buyer.
Farmer still use chemical pesticides when insects damage their crops. Train farmers to practice multiple cropping like grow protective crops such as herbs and lemongrass. Additionally farmers should be encouraged and trained to use botanical pesticides instead or apply integrated pest management (IPM).
Farmers buy organic and semi-organic fertilizers from distributors which greatly adds to production costs. Encourage farmers to produce liquid compost or dry compost by themselves so as to reduce the amount of fertilizers that are bought from distributors.
The vegetables are safe but cannot be classed as organic. Encourage farmers to grow organic vegetables.
Farmers choose the type of vegetables for crop rotation based on market demands which are not suitable for this type of technology. For example the vegetables that are grown all belong to the same family (cucumber, wax melon, luffa and pumpkin). Encourage crop rotation with different families of vegetables, which will not lead to a reduction in soil fertility. It would be better to firstly have a good understanding of the biological characteristics of each plant species.

7. References and links

7.1 Methods/ sources of information

  • field visits, field surveys

A place

  • interviews with land users

A person

  • interviews with SLM specialists/ experts

3 people

When were the data compiled (in the field)?


7.2 References to available publications

Title, author, year, ISBN:

Navin C. (2018) A Safe Vegetable Growers Group in the Svaymeanchey Satrey Samaki Agricultural Cooperative.

Available from where? Costs?

7.3 Links to relevant online information

Title/ description:

Cothren J. (2014) Advantages of Crop Rotation. NC Cooperative Extension. Retrieved on Sep 5 2017 from


Title/ description:

Natural Systems Agriculture (2004) Agronomic Benefits of Intercropping Annual Crops in Manitoba. Retrieved on July 25 2017, from


Title/ description:

My Agriculture Information Bank (2015) Inter Cropping and Its Advantages. My Agriculture Information Bank. Retrieved on July 25 2017 from


Title/ description:

Ben G. (2016). What are the Different Types of Vegetables, Their Distinctions. Retrieved on Sep 17 2017 from


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