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The new technology incorporated introduction of a new high-value specie and establishment of a new water recirculating culture system which is expected to have no discharge into the exis

Ministry of Agriculture & Rural Development

Collaboration for Agriculture & Rural Development

Milestone Appraisal Report

027/07VIE

Improving traditional integrated farming systems (VAC) – a new livelihood option for poor farmers in

the coastal communities

Milestone 5: Status report on the establishment of three improved VAC

systems

September 2009

1 System design

In the first year of the project, three (3) households were chosen for demonstration purposes These three households were chosen based on various selection criteria which were unique and representative of the local area The main features of these three demonstration households were limited land, high nutrients discharged from animal production system (pigs mainly) into the existing water bodies, and willingness of the households to adapt new technologies and extend them to other households One demonstration household was located in Nghe An (Quynh Luu) and other two in Quang Tri (Trieu Hoa and Trieu Lang) The new technology incorporated introduction of a new high-value specie and establishment of a new water recirculating culture system which is expected to have no discharge into the existing water body (pond) The discharge (waste) from the new recirculating system is planned to be used in the production of earth worms, which in turn can be fed to fish and used for horticulture purposes The water recirculating VAC fish production system at each household consisted of one culture tank with biofiltration and waste collection tanks and an associated earth worm house The proposed design for each component of the system is shown in Figures 1 - 4

Figure 1: Proposed design for aquaculture system and system housing

Figure 2: Proposed design of earth worm culture system and housing

Figure 3: Proposed design of sediment tank for aquaculture system

Figure 4: Proposed design of biofilter for aquaculture system

2 Establishment and operating costs and aquaculture production status

2.1 Establishment costs (investment)

Initial establishment for the system including tanks for fish, water storage and filtration, is

presented in Table 1

Table 1: Establishment costs of demonstration system at each household (I - III)

3 12/10/2008 Brick, stones, concrete columns 8,940,000

4 12/10/2008 Labor and electricity 10,200,000

5 26/08/08 Well and install device for pump 3,100,000

1 28/8/08 Brick, sand, stone, wood and bamboo 9,158,000

3 14/10/08 Labor and electricity 9,850,000

4 14/10/08 Cement Piro, nail, top brick 5,433,500

2 29/8/08 Cements and steel lines 5,350,000

4 14/10/08 Cement pipro cement nail, top brick 5,433,500

2.2 Operational cost

Operational costs for the systems include; the electricity required for pumping water, fingerlings,

feed, probiotics and labor The largest proportion of the cost is feed (trash fish or earth worms)

Trash fish is relatively expensive and is an unreliable source of food The operational costs of the

system established at each demonstration household are outlined in Table 2

Table 2: Operation cost of the three demonstration systems

Cost (VND)

Nghe an

Trieu Hoa – Quang tri

Trieu Lang-Quang tri

Fingerling 13.140.000

Feed

Probiotics

Total

2.3 Production status

Initially two systems (Trieu Long and Trieu Hoa) were stocked with eels (Anguilla mamorata) and one (Quynh Luu) with snake head (Channa channa) However, as a result of poor fingerling

quality, all eels in the Trieu Hoa system died one month after stocking the tank The system was subsequently restocked with snake head

The production status of the Quynh Luu and Trieu Hoa systems in 2008 is outlined in Tables 3 and 4

Table 3: Production status of the Quynh Luu (Mr Tung) system

Total feed used (kg) 200

Amount for feed (VND) 800000

Pumping time/day (hr) 1

Electricity cost /unit (VND) 700

Table 4: Production status of the Trieu Hoa (Mr Thieu) system

Total feed used (kg) 286

Amount for feed (VND) 1430000

3 Assessment of recirculating (closed) production system and levels of

nitrogenous waste

The water quality parameters of the Trieu Hoa and Quynh Luu systems are shown in Tables 5

and 6 Tank system included a biofilter and therefore, a lower level of nitrogenous waste was

expected in these systems when compared to the ponds which did not include any filtration

systems

Table 5: Water quality parameters for the system in Trieu Hoa (tank water is treated

(biofilter); pond water is untreated)

Water temp (oC) 24.4 23.6 24.2 23.4 23.2 22.1 23 20.1

Table 6: Water quality of tank in Quynh Luu system

Water parameters were within acceptable ranges for fish health and growth Examination of dead fish suggested that the mass mortality of eels one week after stocking was a result of transportation and poor fingerling quality

4 Lessons learned for adjustment in design and operation of VAC models in Year 2

• If farmers are not financially supported by the project, it is unlikely that they will be convinced to invest

• It must be demonstrated to the farmers that although initial investment is high, proper

design and installation of the system will ensure future profits with minimal maintenance

• A simple system design is recommended

• Water supply for the system is generally not an issue

• Intermittent electricity supply must be taken into consideration for system design and operation Alternatively, a generator could be included in the system design however, this would increase the initial investment and running costs

• Biofiltration is only required at critical times or when water supply is limited The supply water for the system established in Trieu Lang-Quang Tri (Mr Sinh) is of relatively poor quality and provides a good example of a situation where biofiltration should be used

• With the increase of cost for inclusion of biofiltration to the system stocking of a high valued fish species is recommended

• Inclusion of a biofilter is most suitable for systems nursing fry and fingerlings A biofilter improves water quality and therefore reduces the risk of pollution and disease outbreaks which, at present is the bottle neck for the aquaculture nursery industry

• For some species, such as snake head, a filtration is enough to maintain high growth rate

of the fish (Binh, is this supposed to say ‘no’ filtration…?)

• Eels may not a suitable species as;

i fingerlings are collected from the wild which is no longer sustainable, and

5 New VAC Guidelines Manual

Conditions applicable to the improved VAC system;

• Suitable for farms where ponds are non-existent or, exist but are of an area less than

200m2 particularly in areas of limited access to water,

• Availability of raw materials (eg manures from cattle and/or poultry in the area),

• Suitable for culture of fresh and brackish water species

• Recommended for high value species

Table 7 outlines the system requirements for each species

Table 7: Species and culture conditions

Snake head • Cement tank (area = 5 – 40 m²; height = 60 – 70 cm,

surrounded with net)

• Suitable for farms without ponds and unskilled farmers

• Feed with earth worms or trash fish

Goby fish • Cement tank/ponds (area= 5 – 40 m²; height = 60 – 70 cm)

• Salinity 0 – 12%0

• Feed with earth worms or trash fish

Grouper • Cement tank/ponds (area= 5 – 40 m²; height = 1.2 – 1.6 m)

• High quality of water (especially DO and BOD)

• Bio-filter

• Feed earth worms or trash fish

Fry/Fingerling nursing • Cement tank/ponds

• Bio-filter is recommended as the production cycle is short (ie 2 – 8 weeks depending on species)

• Feeding with earth worms is recommended

6 Design and operation

The actual design and operation of the three improved VAC systems installed at each of the three

locations are outlined below Technical notes for the successful culture of earthworms are also

included

6.1 Aquaculture system

13

6.2 Earth worm culture

The initial step to establish an earthworm culture is to add a few egg-capsules or worm “seeds”

to a culture medium of earthworm food in some kind of container or bed (eg a tin can, a small

wooden box, a compost heap, or a specially designed culture bed) The culture must be kept

moist and shaded

6.2.1 House

• Rearing container area should be 20 – 30 m², depending upon the local situation

• The rearing container should be located at a distance of 50cm from the house wall

• House wall should be made of bamboo, or jute materials

• The vertical frame of the house should consist of concrete columns while the horizontal

frame should be made of bamboo

• The suggested material for the roof of the house is palm leaves Piro or plastic are other

ƒ Containers should be in a suitable and convenient location that is, close to manure, away

from strong and direct sunlight and in an area not prone to flooding

ƒ The container floor plays an important role in maintaining the quality of the culture medium It is suggested that the floor should be made of cement-sand or plastic to maintain moisture, protect from ants and protect from external water sources that may

lead to water logging

• Temperature

ƒ The range of temperature should be between 20oC - 30oC When temperature decreases in winter, grass or banana leaves can be applied to cover the surface to maintain temperature

and prevent mass mortality Light can be applied to increase temperature

• Moisture

ƒ High moisture content of the culture medium is required for optimum growth so regular spraying of containers with water is recommended When ambient temperature is high,

spraying of the culture medium should occur at least two times per day

• Light

ƒ Cultures should be protected from sun light In areas where total avoidance of sunlight is unfeasible sedge mat, straw, or leaves can be used to cover the container surface

However, well ventilated conditions surrounding the culture should be maintained

• Gas

ƒ CO2, H2S, SO3, NH3 are particularly toxic Earthworms are highly sensitive to NH3 from

urea waste and thus manures should be treated before use

• Food

ƒ 2 kg of worms requires 1 – 2 kg manure (wet weight) daily Manure can be sourced from cow, buffalo, goat, pig, duck, chicken, straw or other organic materials Fresh manure from cow or/and buffalo is highly recommended Before using any type of manure as a

food source, ammonia should be at least partly removed

ƒ A recommended diet/culture medium for earthworms includes 50% straw, sugar waste,

sawdust; 20% plant by-product; 30% manure from either cow or pig