1. About
Integrated Fish Farming
The principle of integrated fish farming involves
farming of fish along with livestock or/and agricultural crops. This type of
farming offers great efficiency in resource utilization, as waste or byproduct
from one system is effectively recycled. It also enables effective utilization
of available farming space for maximizing production. The rising cost of
protein-rich fish food and chemical fertilizers as well as the general concern
for energy conservation have created awareness in the utilization of rice and
other crop fields and livestock wastes for fish culture. Fish culture in
combination with agriculture or livestock is a unique and lucrative venture and
provides a higher farm income, makes available a cheap source of protein for
the rural population, increases productivity on small land-holdings and
increases the supply of feeds for the farm livestock. The scope of integrated
farming is considerably wide. Ducks and geese are raised in pond, and
pond-dykes are used for horticultural and agricultural crop products and animal
rearing. The system provides meat, milk, eggs, fruits, vegetables, mushroom,
fodder and grains, in addition to fish. Hence this system provides better
production, provides more employment, and improves socio-economic status of
farmers and betterment of rural economy.
Integrated fish farming can be broadly classified into
two, namely: Agriculture-fish and Livestock-fish systems. Agri-based systems
include rice-fish integration, horticulture-fish system, mushroom-fish system,
seri-fish system. Livestock-fish system includes cattle-fish system, pig-fish
system, poultry-fish system, duck-fish system, goat-fish system, rabbit-fish
system.
2. Fish
farming with agriculture
Agri-based systems include rice-fish integration,
horticulture-fish system, mushroom-fish system, seri-fish system. In this
system, fish culture is integrated with agricultural crops such as rice, banana
and coconut, thereby producing fish and agricultural crops under one
interlinked system.
Rice-fish culture
In India, though six million hectares are under rice
cultivation, only 0.03 per cent of this is now used for rice-fish culture. This
type of fish culture has several advantages such as (a) economical utilisation
of land, (b) little extra labour, (c) savings on labour cost towards weeding
and supplemental feeding, (d) enhanced rice yield, and (e) additional income
and diversified harvest such as fish and rice from water, and onion, bean, and
sweet potato through cultivation on bunds. Considering these, it is imperative
to expand fish culture in the rice fields of our country. The paddy fields
retain water for 3-8 months in a year. The culture of fish in paddy fields,
which remain flooded even after paddy harvest, serves an off-season occupation
and additional income to the farmer. This system needs modification of rice
fields, digging peripheral trenches, construction of dykes, pond refuge, sowing
improved varieties of rice, manuring, stocking of fish at 10,000/ha and finally
feeding of stocked fish with rice-bran and oilcakes at 2-3% of body weight.
Paddy-Poultry-Fish Integrated Farming
For the culture of fish in combination with rice,
varieties such as Panidhan, Tulsi, CR260 77, ADT 6, ADT 7, Rajarajan and
Pattambi 15 and 16 are suitable. These varieties not only possess strong root
systems but also are also capable of withstanding flooded conditions. Further,
they have a life span of 180 days and fish culture is possible for about four
to five months after their transplantation. Harvesting is done when fish attain
marketable size.
Fish culture in rice fields may be attempted in two
ways, viz. simultaneous culture and rotation culture. In the former, rice and
fish are cultivated together and in the latter; fish and rice are cultivated
alternately.
Simultaneous Culture
For simultaneous culture, rice fields of 0.1 ha area may
be economical. Normally four rice plots of 250 m2 (25 x 10 m) each may be
formed in such an area. In each plot, a ditch of 0.75 m width and 0.5 m depth
is dug. The dikes enclosing the rice plots may be 0.3 m high and 0.3 m wide and
are strengthened by embedding straw. The ditches have connections with the main
supply or drain canal, on either side of which, the rice plots are located,
through inlet-outlet structures of the dikes. The depth and width of the supply
or drain canal may be slightly smaller than that of the ditches. Suitable
bamboo pipes and screens are placed in the inlet and outlet structures to avoid
the entry of predatory fish and the escape of fish under culture. The ditches
serve not only as a refuge when the fish are not foraging among rice plants,
but also serve as capture channels in which the fish collect when water level
goes down. The water depth of the rice plot may vary from 5 to 25 cm depending
on the type of rice and size and species of fish to be cultured.
The fish species which could be cultured in rice fields
must be capable of tolerating shallow water (15 cm), high temperatures (up to
35ºC), low dissolved oxygen and high turbidity. Species such as Catla catla,
Labeo rohita, Cirrhina mrigala, Cyprinus carpio, Chanos chanos, Oreochromis
mossambicus, Anabas testudineus, Mugil spp., Clarias batrachus, C.
macrocephalus, Lates calcarifer, Channa striatus and C. marulius have
been widely cultured in rice fields.
Simultaneous Culture Of Fresh-Water
Prawn And Rice
Semi-intensive culture of Macrobrachium rosenbergii
could be undertaken in rice fields. Unlike for fish-rice culture, bunds for
fish-prawn culture are raised so as to enclose 12 cm of water for four months,
the period of rice culture. Further, inlets and outlets should be provided with
extended screen, say, 0.3 m above water surface to prevent climbing and escape
of prawns. One or two small sump pits (1 x 2 x 0.5 m) should also be
constructed near the outlet for trapping prawns when water is drained at the
time of harvesting. The stocking of juvenile prawns (2-3 cm size) at the rate
of 1,000/ha may be done after the rice seedlings are well rooted. No
supplementary feeding of prawns is required in this system.
The simultaneous culture has the
following advantages:
• Fish increases rice yield by 5 to 15 per cent, which is chiefly
due to the indirect organic fertilisation through the fish excrement and also
the control of unwanted filamentous algae which may otherwise compete for the
nutrients.
• Tilapia and common carp control the unwanted aquatic weeds which
may otherwise reduce the rice yield up to 50 per cent.
• Insect pests of rice like stem borers are controlled by fish
feeding on them like murrels and catfish.
• Fish feed on the aquatic intermediate hosts such as malaria
causing mosquito larvae, thereby controlling water-borne diseases of human
beings.
• Rice fields may also serve as fish nurseries to grow fry into
fingerlings. The fingerlings, if and when produced in large quantities may
either be sold or stocked in production ponds for obtaining better fish yield
under composite fish culture.
Limitations in simultaneous culture: The simultaneous
fish-rice culture may have some limitations, like (a) use of agrochemicals is
often not feasible, (b) maintaining high water level may not be always
possible, considering the size and growth of fish, (c) fish like grass carp may
feed on rice seedlings, and (d) fish like common carp and tilapia may uproot
the rice seedlings. However, these constraints may be overcome through judicious
management.
Culture procedure
Five days after transplanatation of rice, fish fry (1
cm) are stocked at the rate of 5,000/ha or fingerlings (8-10 cm) at the rate of
2,000/ha. The stocking density can, however, be doubled if supplemental feed is
given daily, particularly if plankton is found depleted after 10 days of
stocking fish. The plankton production in rice fields could, however, be
increased if some amount of fertiliser more than what is required for rice
fields is added. To control the menace of insects, the insecticide Furadon
(Carbofuran) may be used at the rate of 1 kg/ha. The insecticide is mixed with
basal fertilisers and applied once during the final harrowing. It may be stated
that fish grown in insecticide-applied rice fields are safe for human
consumption.
After a period of 10 weeks (if stocked with fry) or six
weeks (if stocked with fingerlings), the rice fields are slowly drained off and
the fish are harvested. The harvesting of fish may be done about a week before
the harvest of rice. The growth rate of fish is also moderate in rice fields as
the production of plankton, the fish food organisms, is rich. Individual growth
of 60 g and a per hectare yield of 500 kg have been reported under the
simultaneous culture practice.
Rotational culture of rice and fish
Through this practice, fish and rice are cultivated
alternately. The rice field is converted into a temporary fishpond after the
harvest. This practice is favoured over the simultaneous culture practice as it
permits the use of insecticides and herbicides for rice production. Further, a
greater water depth (up to 60 cm) could be maintained throughout the fish
culture period.
One or two weeks after rice harvest, the field is
prepared for fish culture. C. carpio is found suitable for this
practice. The stocking densities of fry (2-3 cm) or fingerlings (5-8 cm) for
this pracitce could be 20,000/ha and 6,000/ha, respectively. The fry are
harvested after 10 weeks, while the fingerlings after six weeks. The average
growth of the individual fish under this system has been reported to be about
100 g and a fish yield of about 2,000 kg/ha is possible. Further, it has also
been reported that fish yield could exceed the income from rice in the
rotational culture.
Paddy Cum Fish Culture
Coastal saline soil extends from the main sea coast to a
few or even 50 km at places interior to the main land. The ground water table
under these soils is generally present at a shallow depth and contains high
amount of soluble salts. These salts accumulate on the surface of the soil due
to capillary rise of saline groundwater during dry periods of the year
rendering the soil highly saline. Almost the entire area of the rain fed
coastal saline soil is mono cropped in nature. The major agricultural crop of
kharif is rice, grown during monsoon period when soil salinity is low. During
the rest of the year, the land usually remains fallow due to high salt content
of the soil.
The kharif paddy varieties widely used in such areas are
Mahsuri, Sadamota, Kalomota, Talmugur, Damodar, Dasal, Getu, Nona-patnai, Jaya,
Ratna, Pankaj, Patnai-23, Luni, Cuttackdhandi, Pokkali, Vytilla, Bilikagga,
CSR-4, CSR-6, Matla, Hamilton, Palman 579, BKN, RP-6, FR-46B, Arya, etc. Paddy
cum brackish water fish/ shrimp culture aims at utilizing the summer fallow
period of the coastal saline soil through a short-term brackish water
aquaculture without affecting the subsequent kharif paddy crop. This type of
activity provides the farmers with a substantial subsidiary income during the
fallow season.
In West Bengal, where the salinity is either low or
lowered by fresh water discharge diluting the tidal water, the cultivation of
fish is undertaken in paddy fields. In pokkali fields of Kerala, summer fallow
months are utilized for brackish water aquaculture. The production of fish in
such culture varies from 300 to 1000 kg/ha. The brackish water shrimp culture
is introduced in a big way in such areas as the remuneration is very high. The
species commonly cultured are Penaeus monodon, Penaeus indicus, Metapenaeus
dobsonii and Metapenaeus monoceros.
Technical Parameters
The coastal area is mostly low lying, the elevation
varying usually between sea level and 8 m above the MSL. Fields having
elevation between low and high tide levels are desirable for water exchange
during brackish water aquaculture and also for frequent draining of monsoon
water during desalination process. The sluice in the embankment is essential
for regulating the flow of tidal and drainage waters. The area having more than
1 m tidal amplitude is considered suitable for paddy cum shrimp culture.
Soil quality
Medium textured soils like silty
clay or silty clay loam are most suitable for paddy cum fish/ shrimp culture.
Water quality
Heavy monsoon precipitation for the site is essential
for desalination of the soil after brackish water aquaculture. Intake of
brackish water must be suspended before the onset of monsoon. The cultured
species is harvested and then the land is exposed to monsoon precipitation for
the purpose of desalination.
Pond construction
The paddy plots should be renovated suitably for the
purpose of paddy cum brackish water aquaculture. Construction of an earthen
dyke surrounding the paddy plot is essential for retaining water and also for
holding the fish and shrimp during aquaculture. The height of the dyke is
required to be maintained between 50 and 100 cm depending upon the topography
of the plot and tidal amplitude at the site. A perimeter canal is necessary on
the inner periphery of the plot. For a one ha paddy plot, the width and depth
of the canal may be about 2 m and 1 m respectively. The earth removed from
excavating the canal may be utilized for constructing or strengthening the
dyke. In addition to the perimeter canal, two cross trenches of about 1 m width
should also be constructed at both the directions. The bottom of the trenches
should be above the perimeter canal so that during the course of desalination,
entire water can be easily removed to the canal. The area covered by the
perimeter canal and the trenches will be about 12% of the total land area.
Water supply and drainage
The entry of tidal water during the culture is made
through feeder canal and the flow of water into the field is regulated by a
sluice gate fitted with wooden shutters and placed at about 30 cm height from
the main plot. During high tide, water is taken into the plot after sieving
through velon nets and split bamboo mats to prevent entry of any kind of fish/
shrimp and other undesirable species, especially carnivores. Another sluice is
used for draining out water from the culture plot to the feeder canal at low
tide periods for water exchange, desalination and drainage of excess water. On
the entry and exit mouths of the slice gate, wooden shutters are provided to
regulate the movement of water.
Pond management
The plots are prepared in two phases, once for brackish
water aquaculture and again for paddy cultivation. For aquaculture crop, the
plot is sun dried after the kharif harvest. If necessary, to rectify acidic
soils, lime is applied depending on requirement of the soil. Usually no
inorganic fertilization is done. However, urea may be used in extreme cases of
nitrogen deficiency of soils @ 60 kg N/ha. Some shade zones are provided over
the perimeter canal with twigs, hay, palm leaves etc., so that during summer
the shrimp can take shelter and also hide themselves from predation.
Stocking
The paddy field is made ready for stocking and Penaeus
monodon or Penaeus indicus are stocked @ 3 nos/sq.m.
Feeding
Although natural food items have good conversion values
but they are difficult to procure in large quantities and maintain a continuous
supply. Hence only supplementary feed is given
Harvesting
Complete harvesting is done by draining the pond water
through a bag net and hand picking. The average culture period in paddy fields
is around 100-120 days during which time the shrimps will grow to 35 gm size.
Harvested shrimps can be kept between layers of crushed ice before transporting
the consignment to market.
Fish Culture In 'Pokkali' Fields
In Kerala, fish and prawn are cultured on rotational
basis in Pokkali rice fields. These fields under the influence of Vembanad
backwaters, which are in, turn controlled by tides. As these fields are flooded
during southwest monsoon (June-Septemeber) rice is cultivated. Fish and prawns
are cultured during other periods. Immediately after the harvest of rice, the
fields are leased out for the culture of fish and prawns. The young of fish and
prawns enter the fields from nearshore waters along with high tides. Suitable
management cultures these young until harvest in May. These fields are rich in
plankton owing to the decaying of paddy stumps. A prawn yield of 500-1,200
kg/ha has been obtained from Pokkali fields. After the prawn harvest, the water
is drained off. Subsequently, the saline nature of rice fields is nullified
because of the monsoon rains and the fields are again made fit for rice
culture.
3.
Horticulture-fish system
The top, inner and outer dykes of ponds as well as
adjoining areas can be best utilized for horticulture crops. Pond water is used
for irrigation and silt, which is a high-quality manure is used for crops,
vegetables and fruit bearing plants. The success of the system depends on the
selection of plants. They should be of dwarf type, less shady, evergreen,
seasonal and highly remunerative. Dwarf variety fruit bearing plants like
mango, banana, papaya, coconut and lime are suitable, while pineapple, ginger,
turmeric, chilli are grown as intercrops. Plantation of flower bearing plants
like tuberose, rose, jasmine, gladiolus, marigold and chrysanthemum provide
additional income to farmers.
Ideal management involves utilization of middle portion
of the dyke. Residues of vegetables cultivated could be recycled into
fishponds, particularly when stocked with fishes like grass carp. Grass carps
can be stocked @ 1000/ha and addition of common carps are beneficial for
utilizing feacal debris. In mixed culture of grass carps along with rohu, catla
and mrigal, in 50: 15: 20: 15 ratio at a density of 5000 fish/ha. Similarly
when banana or coconut is cultivated in rows in wetlands, the ditches made
between such rows act as supply or drainage canals. These canals serve as fish
culture systems owing to their round-the-clock supply of water and rich insect
populations. Larvivorous air-breathing fish species such as snakeheads C.
marulius and C. striatus and tilapia, O. mossambicus are
ideal species for culturing in this system. This integrated system fetched
20-25% higher return compared to aquaculture alone.
4. Mushroom-Fish System
Cultivation of edible mushroom in India is quite recent.
Three types of mushrooms being commercially cultivated in India are Agaricus
bisporus, Voloriella spp. and Pleurotus spp., commonly known
as European button, paddy straw and oyster mushroom. Mushroom cultivation
requires high degree of humidity and therefore its cultivation along with
aquaculture tremendous scope. Method of cultivation involves use of dried
paddy-straw chopped into 1.2 cm bits, soaked in water overnight. Excess water
is drained off. Horsegram powder (8 g/kg straw) and spawn (30 g/kg straw) is
added and mixed with wet straw in alternating layers. Perforated polythene bags
are filled with substrate and kept in room at 21o-35oC with required light and
ventilation. The mycelial growth occurs within 11-14 days. Polythene bags are
cut open at this stage, water is sprayed twice a day and in a few days mushroom
crop becomes ready for harvest. The paddy-straw after mushroom cultivation is
utilized for cattle feeding.
5. Seri-Fish System
In this integration, mulberry is the producer; silkworm
is the first consumer while fish is the secondary consumer, ingesting silkworm
faeces directly. Inorganic nutrient in the silkworm faeces are utilized by
phytoplankton, and filter-feeding fish in turn consumes heterotrophic bacteria.
The optimum range of temperature and humidity is 15-32oC and 50-90%
respectively. The seri-fish system provides linkages between mulberry and pond
sub-system. Harvested mulberry leaves are fed to silkworm and the waste
material obtained from silkworm rearing enters fish-pond as a mixture of
mulberry leaves and silkworm excrement. Mulberry dykes yield leaves at 30
tonnes/ha/year, when fed to silkworm 16-20 tonnes of waste is produced. In 1 ha
mulberry-pond system, 50% of area is kept for dyke and remaining is kept as
water area. During winter, vegetables are inter-planted with mulberry. A
production of 30 tonnes of mulberry-leaves/ha, 3.75 tonnes of vegetables/ha can
be attained.
6.
Livestock-fish system
Livestock-fish system includes cattle-fish system,
pig-fish system, poultry-fish system, duck-fish system, goat-fish system,
rabbit-fish system. In this practice, excreta of ducks, chicks, pigs and cattle
are either recycled for use by fish or serve as direct food for fish. Hence,
the expenditure towards chemical fertilisers and supplementary feeds for fish
culture is not only curtailed to the barest minimum but also there is economy
of space. Integration of fish culture and livestock farming is in vogue in many
countries and the income realised has been found to be more than that of
exclusive fish farming in ponds.
The main potential linkages between livestock and fish
production concern use of nutrients, particularly reuse of livestock manures
for fish production. The term nutrients mainly refers to elements such as
nitrogen (N) and phosphorous (P) which function as fertilizers to stimulate
natural food webs rather than conventional livestock nutrition usage such as
feed ingredients, although solid slaughterhouse wastes fed to carnivorous fish
fall into the latter category.Both production and processing of livestock
generate by-products that can be used for aquaculture. Direct use of livestock
production wastes is the most widespread and conventionally recognized type of
integrated farming. Production wastes include manure, urine and spilled feed;
and they may be used as fresh inputs or be processed in some way before use.
Use of wastes in static water fishponds imposes
limitations in terms of both species and intensity of culture. Stimulation of
natural food webs in the pond by organic wastes can support relatively low
densities of herbivorous and omnivorous fish but not a large biomass of
carnivorous fish. These biological processes are also temperature dependent.
The optimal temperature range is between 25-32°C although waste-fed aquaculture
in sub-tropical and temperate zones where temperatures rise seasonally has also
been successful. Processing wastes through organisms such as earthworms and
insect larvae that feed on them and concentrate nutrients to produce ‘live
feeds’ is an alternative approach to raising fish needing high levels of
dietary animal protein. Livestock processing can also provide a wide variety of
wastes that vary from dilute washing water to high value meat and bloodmeal
that can be used as high value fish feeds or feed ingredients. If enough of
these types of feeds are available, high density and intensive production of
carnivorous fish species can be supported. Aquaculture may also provide inputs
and other benefits to livestock production. A variety of aquatic plants e.g.
duckweeds and the aquatic fern Azolla have proven potential as livestock
feeds; and invertebrates such as snails and crustaceans can be used for poultry
feeds.
Based on the type of livestock used for integration
there are many combinations in livestock-fish systems. The important ones are
discussed below.
Cattle-Fish Culture
Fish farming using cow manure is one of the common
practice all-over the world. Countries like Hong Kong, Taiwan and Philippines
have undertaken the integrated fish farming on a commercial scale and obtained
considerable fish yields. Cowsheds are constructed in the vicinity of fishponds
and the slurry from the biogas plants may be discharged into fishponds. A
healthy cow excretes over 4,000-5,000 kg dung, 3,500-4,000 litre urine on an
annual basis. Cow manure particles sink slower (6 cm/min) than any other
livestock. This provides sufficient time for fish to consume edible portions
available in dung. Manuring with cowdung, which is rich in nutrients result in
increase of natural food organism-detritus and bacteria in fishpond. A unit of
5-6 cows can provide adequate manure for 1 ha of pond. In addition to 9,000 kg
of milk, about 3,000-4,000 kg fish/ha/year can also be harvested with such
integration.
Cowshed should be built close to fishpond to simplify
handling of cow manure. Cow requires about 7,000-8,000 kg of green grass
annually. Grass carp utilizes the leftover grasses, which are about 2,500 kg.
Fish also utilizes the fine feed wasted by cows, which consist of grains. In
place of raw cowdung, biogas slurry could be used with equally good production.
20,000-30,000 kg of biogas slurry is recycled in 1 ha water area to get over
4000 kg of fish without feed or any fertilizer application.
7.
Pig-Fish system
This system of integration is very common in China,
Taiwan, Vietnam, Thailand, Malaysia and Hungary. Pigs are fed largely on
kitchen waste, aquatic plants and crop wastes. The waste produced by 30-35 pigs
is equivalent to 1 tonne of ammonium sulphate. Exotic breeds such have White
Yorkshire, Landrace and Hampshire are reared in pig-sty near the fish pond. A
floor space of 3-4 m2 is provided and boars, sows and finish stocks are housed
separately. Maize, groundnut, wheat-bran, fishmeal, mineral mixes are provided
as concentrate feed-mixture.
Depending on the size of the fishponds and their manure
requirements, such a system can either be built on the bund dividing two
fishponds or on the dry-side of the bund. Pigsties, however, may also be
constructed in a nearby place where the urine and dung of pigs are first
allowed to the oxidation tanks (digestion chambers) of biogas plants for the
production of methane for household use. The liquid manure (slurry) is then
discharged into the fishponds through small ditches running through pond bunds.
Alternately, the pig manure may be heaped in localised places of fishponds or
may be applied in fishponds by dissolving in water.
Pigdung contains more than 70 per cent digestible feed
for fish. The undigested solids present in the pigdung also serve as direct
food source to tilapia and common carp. A density of 60-100 pigs has been found
to be enough to fertilise a fish pond of one hectare area. The optimum dose of
pig manure per hectare has been estimated as five tonnes for a culture period
of one year. Such a quantity may be obtained from 50 well-fed pigs. If the
manure is to be applied in a dry form, a dosage of 400 kg/ha/day for 12 times
in a year will be required. Fish like grass carp, silver carp and common carp
(1:2:1) are suitable for integration with pigs.
Pigs attain slaughter maturity size (60-70 kg) within 6
months and give 6-12 piglets in every litter. Their age at first maturity
ranges from 6-8 months. Fish attains marketable size in a year. Keeping in view
the size attained, prevailing market rate, demand of fish, partial harvesting
of table-sized fish is done. Final harvesting is done after 12 months of
rearing. It is seen that a fish production of 3,000 kg/ha could be achieved
under a stocking density of 5,000 fish fingerlings/ha in a culture period of
six months. In India, through pigfish culture, the fish yield was doubled
compared to that of polyculture with intensive feeding.
8.
Poultry-Fish Culture
The droppings of chicks rich in nitrogen and phosphorus
would fertilise fishponds. Poultry housing, when constructed above the water
level using bamboo poles would fertilise fishponds directly. This system
utilizes poultry droppings for fish culture. Production levels of 4500-5000
kg/fish/ha could be obtained by recycling pond manure into fishponds. Broiler
production provides good and immediate returns to farmers. Procurement of
quality chicks, housing, brooding, feeding and disease management are important
for this type of system. In fish poultry integration, birds housed under
intensive system are considered best. Birds are kept in confinement with no
access to outside. Deep litter is well suited for this type of farming. About
6-8 cm thick layer prepared from chopped straw, dry leaves, saw dust or
groundnut shell is sufficient.
Rhode island or Leghorn birds are preferred in
poultry-fish system for their better growth and egg laying capacity. The number
of chicks used for this system is about 2500/ha however; the stocking density
of chicks may be increased in the event of increase in the stocking density of
fish fingerlings. Egg-type birds are fed with starter 0-8 weeks, grower 8-20
weeks and brooder feed 20 weeks onwards, while broilers are fed 0-4 weeks with
starter and 4-6 weeks with finisher feed. The deep poultry litter is applied to
pond in daily doses at 30-35 kg/ha. One adult chicken produces about 25 kg of
compost poultry-manure in a year; 1000 birds can provide sufficient manure for
1 ha water body.
Fertilization with poultry manure results in a
production of 3000-4000 kg fish, 90,000-100,000 eggs and over 2,500 kg meat/
year. A fish production of 10 tonne/ha could be obtained by culturing tilapia,
common carp and murrels with a stocking density of 20,000 fingerlings/ha and
chick density of 4,000/ha. No chemical fertilisers or supplemental feeds have
to be given at any stage. By stocking 5,000 giant fresh-water prawn,
Macrobrachium rosenbergii and 1,500 silver carp in one-hectare area, one can
harvest 600 kg of prawns and an equal amount of fish in a four-month culture
period.
9.
Duck-Fish Culture
Duck-fish integration is the most common integration in
China, Hungary, Germany, Poland, Russia and some parts of India. A fish-pond
being a semi-closed biological system with several aquatic animals and plants,
provide excellent disease-free environment for ducks. In return ducks consume
juvenile frogs, tadpoles and dragonfly, thus making a safe environment for
fish. Duck dropping goes directly in pond, which in turn provide essential
nutrients to stimulate growth of natural food. This has two advantages, there
is no loss of energy and fertilization is homogeneous. This integrated farming
has been followed in West Bengal, Assam, Kerala, Tamil Nadu, Andhra Pradesh,
Bihar, Orissa, Tripura and Karnataka. Most commonly used breed for this system
in India is the ‘Indian runners’.
It is highly profitable as it greatly enhances the
animal protein production in terms of fish and duck per unit area. Ducks are
known as living manuring machines. The duck dropping contain 25 per cent
organic and 20 per cent inorganic substances with a number of elements such as
carbon, phosphorus, potassium, nitrogen, calcium, etc. Hence, it forms a very
good source of fertiliser in fish ponds for the production of fish food
organisms. Besides manuring, ducks eradicate the unwanted insects, snails and
their larvae which may be the vectors of fish pathogenic organisms and water-borne
disease-causing organisms infecting human beings. Further, ducks also help in
releasing nutrients from the soil of ponds, particularly when they agitate the
shore areas of the pond.
For duck-fish culture, ducks may be periodically allowed
to range freely, or may be put in screened resting places above the water.
Floating pens or sheds made of bamboo splits may also be suspended in the pond
to allow uniform manuring. The ducks may be stocked in these sheds at the rate
of 15 to 20/m2. It is better if the ducks are left in ponds only until they
reach marketable size. Depending on the growth rate of ducks, they may be
replaced once in two to three months. About 15-20 days old ducklings are
generally selected. The number of ducks may be between 100 and 3,000/ha
depending on the duration of fish culture and the manure requirements.
For culturing fish with ducks, it is advisable to
release fish fingerlings of more than 10 cm size, otherwise the ducks may feed
on the fingerlings. The stocking density of fingerlings also depends on the
size of pond and number of ducks released in it. As the nitrogen-rich duck
manure enhances both phyto- and zooplankton production, phytoplankton-feeding
silver carp and zooplankton-feeding catla and common carp are ideal for duck-fish
culture. The fish rearing period is generally kept as one year and under a
stocking density of 20,000/ha, a fish production of 3,000-4,000 kg/ha/year has
been obtained in duck-fish culture. In addition to this, eggs and duck-meat are
also obtained in good quantity on an annual basis.
http://www.vuatkerala.ofile:///E:/Animal%20Husbandry/TNAU-Agri%20Tech%20Portal/ani_chik_grower&layer%20mgt.html
http://www.vuatkerala.org/static/eng/advisory/fisheries/culture_fisheries/integrated_farming/introduction.htm
