Intercropping of vegetables to control pests along the Mekong river bank [Cambodia]

Natural Vegetable

technologies_2098 - Cambodia

Completeness: 90%

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)

Acting Chief of District Office of Agriculture, Forestry and Fisheries, Preaek Prasab:
land user:

Y Soklang



Chief of District Office of Agricultue, Forestry and Fisheries, Sambo:
Official at District Office of Agriculture, Forestry and Fisheries, Chetr Borie:

Ly Saravuth

Chetr Borie district office Agriculture, Forestry and Fisheries


Name of project which facilitated the documentation/ evaluation of the Technology (if relevant)
Scaling-up SLM practices by smallholder farmers (IFAD)
Name of the institution(s) which facilitated the documentation/ evaluation of the Technology (if relevant)
Royal University of Agriculture (RUA) - Cambodia

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?


2. Description of the SLM Technology

2.1 Short description of the Technology

Definition of the Technology:

Cropping by setting up alternative rows of different crops: lettuce, pak choi, escarole, choy sum and morning glory for a reduction in damage from insects. This technique incorporates the spreading of lime in advance for control of soil pests, and plant derived pesticide is applied during the cultivation period. This technique is applied on the Mekong river bank in Kratie province.

2.2 Detailed description of the Technology


Intercropping is a technique of cropping in which two or more crops are grown in different alternate rows at the same time (Pawan et al., 2012). The crops grown by the farmers are lettuce, pak choi, choy sum, escarole and morning glory. This technique was applied using 1080 square meters of land along the Mekong's river bank in Kratie province. In applying this technique, the farmer prepared the land, after which he prepared the rows across the slope of the river bank. Lettuce was planted in the first row, then pak choi, choy sum, escarole, and then morning glory, with the crop sequence being repeated in the following rows. Intercropping helps to reduce the damage from insects. Lettuce is a crop that insects dislike because of its bitter taste. Under the intercropping practice with the vegetables that insects dislike, the level of insect damage is reduced because, when facing such repellent crops, the insects normally disappear rather than go to the next row, even though it might be a crop they like.

Crops are easily damaged by insects when grown as a single species that insects like. In intercropping, even if the insects damage one crop, the other crops often survive without insect damage. To apply this technology more effectively, farmer used botanical pesticide that was produced by the farmer himself based on plant ingredients such as neem bark, boraphed, strychnine plant, derris, etc. Such natural pesticide ingredients are crushed and soaked in water for 15 days, after which l liter is mixed with 15 liters of water(Yang et al., 2006). The solution is sprayed on the crops on a daily basis when insects are present.

Soil preparation: The soil is ploughed and dried for 7 to 8 days, then aligned into rows with lime being applied for a period of 6 days to disperse the bad bacteria in the soil. Nursery preparation of escarole, pak choi and choy sum takes about 20 days before transplanting (morning glory was planted by direct seeding). Lettuce is only 10 days old when it is transplanted. Lettuce can be harvested within 30 days after transplanting, while morning glory is grown for about 38 days before being harvested. The farmer used organic fertilizer and cow manure to improve the soil fertility. The farmer makes the rows across the slope of the river to prevent soil erosion during heavy rainfall. To provide protection from the potential adverse effects of direct sunlight and rain, the farmer used a temporary 2 meters high net roof supported by bamboo poles, to provide cover. A net fence was also constructed around the crop area to provide protection from animals such as dogs and chickens. In relation to produce price, pak choi returned 3.500 to 4.000 riel per kilogram, morning glory 2.000 riels per kilogram, choy sum 2.000 to 3.000 riel per kilogram, escarole 3.000 to 3.500 riel per kilogram and lettuce 4.000 riel per kilogram.

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:

Ta Mau Leu village, Kampong Kor Commune, Preaek Prasab District, Kratie Province

Further specification of location:

Land is along Mekong River

Specify the spread of the Technology:
  • applied at specific points/ concentrated on a small area

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 land users' innovation

3. Classification of the SLM Technology

3.1 Main purpose(s) of the Technology

  • reduce, prevent, restore land degradation
  • create beneficial economic impact
  • Reduce soil erosion by making rows across the slope, prevent crops’ exposure to sunlight and rain, reduce insects

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



  • Annual cropping
  • Lettuce, pok choi, choy sum, escarole and morning glory
Annual cropping system:

Vegetables - wheat/barley/oat/upland rice

Number of growing seasons per year:
  • 3

The farmer cultivates vegetables from November to July. In average the crops grow for 45 days.

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:




  • Annual cropping
Annual cropping system:

Vegetables - wheat/barley/oat/upland rice

Is intercropping practiced?


Is crop rotation practiced?



Before the farmer did intercropping and crop rotation he only grew onion.

3.4 Water supply

Water supply for the land on which the Technology is applied:
  • mixed rainfed-irrigated

Using water from Mekong River.

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

  • A2: Organic matter/ soil fertility
structural measures

structural measures

  • S4: Level ditches, pits
  • S9: Shelters for plants and animals
management measures

management measures

  • M5: Control/ change of species composition

3.7 Main types of land degradation addressed by the Technology

soil erosion by water

soil erosion by water

  • Wr: riverbank erosion
physical soil deterioration

physical soil deterioration

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

biological degradation

  • 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

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

4.1 Technical drawing of the Technology


Mr. Khoun Sophal and Ms. Lay Nary



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:

1080 square meters

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:


4.3 Establishment activities

Activity Timing (season)
1. Rent soil for cultivating vegetables November
2. Prepare soil (plow and dry soil, make row and spread the lime) December
3. Material for building (net, pole of bamboo, tank and plastict bowl) when cultivation
4. Seeds when cultivation
5. Organic and manure fertilizer when cultivation and maintenance

Organic fertilizer the farmer bought from Vann Long company

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 Prepare soil person-day 3.0 17000.0 51000.0 100.0
Equipment Pumping machine set 1.0 1000000.0 1000000.0 100.0
Equipment Hoe piece 1.0 13000.0 13000.0 100.0
Equipment Rake piece 1.0 15000.0 15000.0 100.0
Equipment Hose piece 14.0 16000.0 224000.0 100.0
Equipment Big basket pair 1.0 50000.0 50000.0 100.0
Plant material Seed of lettuce package 15.0 10000.0 150000.0 100.0
Plant material Choy sum package 15.0 6000.0 90000.0 100.0
Plant material Escarole package 6.0 6000.0 36000.0 100.0
Plant material Morning glory kilogram 14.0 10000.0 140000.0 100.0
Plant material Pok Choi Can 2.0 7000.0 14000.0 100.0
Fertilizers and biocides Lime kilogram 2.0 2500.0 5000.0 100.0
Fertilizers and biocides Organic fertilizer sack 1.0 130000.0 130000.0 100.0
Construction material Net piece 3.0 260000.0 780000.0 100.0
Construction material water tank pair 1.0 50000.0 50000.0 100.0
Construction material Big plastic bowl piece 3.0 10000.0 30000.0 100.0
Construction material storage tank piece 1.0 80000.0 80000.0 100.0
Construction material Nylon net for the construction for a protective border fence. piece 3.0 58000.0 174000.0 100.0
Other Rent land year 1.0 300000.0 300000.0 100.0
Other Bamboo pole 20.0 4000.0 80000.0 100.0
Total costs for establishment of the Technology 3412000.0
If land user bore less than 100% of costs, indicate who covered the remaining costs:

He spend all on this establishment and ows some payment to the seller of the equipment.

4.5 Maintenance/ recurrent activities

Activity Timing/ frequency
1. Weeding, prepare soil and put fertilizer When the crop is at 7 days.
2. Irrigation (morning and evening) every day
3. Spray botanical pesticide spread pesticide when there are insect on crop
4. Diesel (one month 30 liters) Two times per day (morning and afternoon.

He sprays pesticide when he has insects and uses gasoline to pump water (30 liters of gasoline per month).

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 weeding (by farmer) person-day 4.0 17000.0 68000.0 100.0
Labour prepare soil and put fertilizer ( by farmer) person-day 4.0 17000.0 68000.0 100.0
Labour Spray pesticide person-day 12.0 17000.0 204000.0 100.0
Equipment Pesticide sprayer equipment use by hand set 1.0 80000.0 80000.0 100.0
Equipment Diesel liter 90.0 2350.0 211500.0 100.0
Total costs for maintenance of the Technology 631500.0

When buying material, some owe seller and some give money to seller

4.7 Most important factors affecting the costs

Describe the most determinate factors affecting the costs:

The price of fertilizer and seeds depends on type of seed and market price.

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 average annual rainfall in 2015 was 1138.2 mm, in 2014 1696.5 mm, in 2013 1661.8 mm.

Indicate the name of the reference meteorological station considered:

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
Comments and further specifications on topography:

soil is a slope on Mekong River Bank.

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:
  • high (>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 pH = 5

5.4 Water availability and quality

Ground water table:

5-50 m

Availability of surface water:


Water quality (untreated):

good drinking water

Is water salinity a problem?


Is flooding of the area occurring?




Comments and further specifications on water quality and quantity:

It is flooded all year because it's close to the river.

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:
  • less than 10% of all income
Relative level of wealth:
  • average
Individuals or groups:
  • individual/ household
Level of mechanization:
  • manual work
  • mechanized/ motorized
  • men
Age of land users:
  • middle-aged
Indicate other relevant characteristics of the land users:

He is 37 years old.

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

He owns land of 1 hectare, rents land in raining season 1000 square meter, cost 200000 riels/year, and rents the other land 1080 square meter, cost 300000 riels/year.

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

Land ownership:
  • individual, titled
  • rent
Land use rights:
  • leased
  • individual
Water use rights:
  • open access (unorganized)

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:

Before farmer grew only onion but now grows several crops.

crop quality

Comments/ specify:

Before farmer used chemical pesticide and chemical fertilizer but now farmer uses botanical pesticide and natural fertilizer.

risk of production failure

Comments/ specify:

The farmer does the intercropping that helps to reduce damage from insects and he also uses only botanical pesticide.

product diversity

Comments/ specify:

Before farmer grew only onion but now farmer grows multiple crops such as Escarole, Choy sum, Pok choi, Lettuce and Morning glory.

land management

Comments/ specify:

Because of the intercropping and crop rotation the crops absorb different nutrients from soil. Natural fertilizer makes soil rich in nutrition.

Water availability and quality

irrigation water quality

Comments/ specify:

There is no water pollution because no more chemical pesticide is used, he uses only botanical pesticide.

Income and costs

expenses on agricultural inputs

Comments/ specify:

Before he bought chemical pesticides against insects, now he uses botanical pesticide because he can do it by himself.

farm income

Comments/ specify:

Reducing chemical fertilizer and pesticide use and instead using natural fertilizer and botanical pesticide.

economic disparities

Comments/ specify:

The farmer livelihood is better after practicing this technology because farmer gets more money by having more crops, there is no need to buy chemical pesticides and he has a healthy life.


Comments/ specify:

Workload is a bit increased because of different crops.

Socio-cultural impacts

food security/ self-sufficiency

Comments/ specify:

For food security is better than before because farmer can get better income, before grew only one crop but now he changed to grow multiple crops.

health situation

Comments/ specify:

No use of chemical pesticide which harms the health.

SLM/ land degradation knowledge

Comments/ specify:

Farmer can made botanical pesticide by himself and uses natural fertilizer.

Ecological impacts

Water cycle/ runoff

surface runoff

Comments/ specify:

Flooding make loss loamy soil and increase level sedimentation at down stream by plough or ridge soil at river bank

excess water drainage

Comments/ specify:

Use net roof and create ridge of the row across the slope of the river bank to reduce water flow.


Comments/ specify:

Cover crops can protect soil moisture and net roof is reducing 60% of evaporation.


soil moisture

Comments/ specify:

The cover crops can keep good soil moisture.

soil compaction

Comments/ specify:

Farmer uses cow manure bough from other farmers or collect at the rice field and organic fertilizer bought from the fertilizer company.

nutrient cycling/ recharge

Comments/ specify:

In intercropping each crop and rotation techniques absorbs different nutrients and this creates a balance.

Biodiversity: vegetation, animals

pest/ disease control

Comments/ specify:

Reduce diamond-back moth, striped flea beetle and black cutworm.

6.2 Off-site impacts the Technology has shown

downstream siltation

Comments/ specify:

When the land user ploughs the soil and rakes it, some topsoil will be removed when there is rainfall. To minimize the soil surface runoff, farmer constructed the bamboo pole with the net roof and created a ridge of the row across the slope of the river bank, so the soil sediment flow is increased only very little.

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
seasonal temperature wet/ rainy season increase well
annual rainfall decrease well
seasonal rainfall wet/ rainy season decrease well
other gradual climate change this year frequently raining, last year rarely raining moderately

Climate-related extremes (disasters)

Meteorological disasters
How does the Technology cope with it?
tropical storm not well
Climatological disasters
How does the Technology cope with it?
heatwave moderately
extreme winter conditions not well
drought well
Hydrological disasters
How does the Technology cope with it?
general (river) flood moderately
flash flood moderately
Biological disasters
How does the Technology cope with it?
epidemic diseases not well
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:


Long-term returns:


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

slightly positive

Long-term returns:



Regarding the short-term returns, the farmer spent a lot of money to buy natural or organic fertilizer because at the beginning there is the infertile soil. However, after long-term practice there is no need of much natural or organic fertilizer.

6.5 Adoption of the Technology

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

In this village it is only one farmer who is implementing this technology.

6.6 Adaptation

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


If yes, indicate to which changing conditions it was adapted:
  • changing markets
Specify adaptation of the Technology (design, material/ species, etc.):

Farmer grows crops according to the market demand, for example: The market needs lettuce in the dry season, especially in March and April, lettuce have a high price: one kilogram is 4000 to 5000 riels.

6.7 Strengths/ advantages/ opportunities of the Technology

Strengths/ advantages/ opportunities in the land user’s view
High income
Preventing soil from compaction by using cow manure and organic fertilizer and reduce heat by using temporary net roof.
Reduce the insects by diversification of crops.
Strengths/ advantages/ opportunities in the compiler’s or other key resource person’s view
Improves daily income.
Reduced the use of chemical fertilizers and pesticides.
Helps to improve soil condition.

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?
Still have some problems with diamond back moth and striped flea beetle. When the spraying of the chemical pesticide brings no result, they change the type of crops and use botanical pesticide which helps to get rid of the black moth and flea beetle.
Weaknesses/ disadvantages/ risks in the compiler’s or other key resource person’s view How can they be overcome?
Plough the land by the river side causes the loss of loamy soil and increases the level of sediment downstream during flood events. Reduce plowing the soil or ridging of soil before flooding.
Have problems with insect (diamond back moth and striped flea beetle). Use botanical pesticide made by farmer and change cropping system.

7. References and links

7.1 Methods/ sources of information

  • field visits, field surveys

1 place

  • interviews with land users

1 person

  • interviews with SLM specialists/ experts

3 persons

When were the data compiled (in the field)?


7.2 References to available publications

Title, author, year, ISBN:

DanChurchAid/Christian Aid. (2015). Farmer book: Kit of best Agriculture Technologies to Adapt with climate change. Phnom Penh: Ministry of Agriculture, Forestry and Finsheries. (in Khmer)

Available from where? Costs?

Ministry of Agriculture, Forestry and Finsheries

Title, author, year, ISBN:

Pawan K. et al., (2012).Manual on cropping system and sustainable agriculture:Department of Agronomy CCS Haryana Agricultural University Hisar-125004

Available from where? Costs?

Department of Agronomy CCS Haryana Agricultural University Hisar-125004

Title, author, year, ISBN:

Yang S. et al.,(2008). Kit of botanical pesticide.CEDAC. (in Khmer)

Available from where? Costs?

The Cambodian Center for Study and Development in Agriculture

7.3 Links to relevant online information

Title/ description:

Chan M. (2015). VOA program: Cambodian Farmers Prosper by Going Organic. Retrieved on 15/01/2018 from


Title/ description:

AGRISUD CAMBODGE (2017). Crop production. Retrieve on 20/12/2017 from


Title/ description:

Deen B. (2016). Intercropping: Principle and Types. Retrieve on 20/12/2017 from


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