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close this bookWorkshop to Produce an Information Kit on Farmer-proven. Integrated Agriculture-aquaculture Technologies (IIRR, 1992, 119 p.)
close this folderFish management and feeding
View the documentUsing animal wastes in fish ponds
View the documentSewage-fed fish
View the documentBiogas slurry in fish culture
View the documentPlant sources of feed for fish

Using animal wastes in fish ponds

HOW ANIMAL WASTES WORK IN A POIND


How animal wastes work in a poind

· Direct feeding value of pure wastes is known to be poor.
· Wastes act by:

- stimulating phytoplankton production; and,
- acting as substrate for bacterial production (detritus).

These two processes are strongly interlinked, since phytoplanktons are a major source of detritus for bacterial production. Also, phytoplanktons, through photosynthesis, are the chief producers of dissolved oxygen in the pond used by all organisms including fish.

CHECKLIST FACTORS TO CONSIDER BEFORE USING ANIMAL WASTES

· Are wastes available already on-farm? If so, are the wastes already used? Should they be divided for use in fish culture?

Livestock wastes are often important as crop fertilizers and fuel. Consider the opportunity costs.

· Is it worth raising livestock, especially to generate wastes for aquaculture?

Consider:

· costs/difficulties of doing so (e.g., feed availability and cost; marketing difficulties; technical abilities and interest of farmers)

· inorganics are now much cheaper to use than livestock manure in many places.

MANAGEMENT FACTORS TO CONSIDER

1. Are all wastes to be used in fish culture?

It some wastes are to be used elsewhere, the wastes should be collectible prior to entering the pond (e.g., use a sump). Also, wastes should be available in larger quantities at certain periods when their use should be reduced for fish culture (e.g., during cool season).

LAYOUT/DESIGN OPTIONS


On the Pond Dike

Pens should be close to the pond to reduce labor cost of loading waste.


Over the Pond

Over the pond is usually cooler, more humid.

In the layout/design aspect, consider:

· size and number of livestock space availability/land cost; and,
· relative cost of materials.

2. Can all the wastes be collected?

Feedlot livestock are kept confined at all times so all the wastes can be collected and used.

Small-scale farmers often allow livestock to graze or scavenge during daylight hours and only confined at night. This reduces feed costs considerably, often allowing only on-farm or low-cost supplementary feeds to be given. But collectible wastes will be less.

3. Livestock may be penned at the farmer's house for security or traditional reasons; this may limit potential advantages of integration.

4. Ponds may be multifunctional:

Large animals are usually denied access to the pond because entry to and wallowing in can destroy the dikes and cause turbidity which reduces natural food production.

Maybe design the pond to allow limited access.


Fence around pond keeps Buffalo out.


Fence across pond lets Buffalo in water.

Livestock wastes vary in terms of both quantity and quality which are affected by the following factors:

· Food quality of livestock
· Species and size
· Stage in life cycle (breeder, grower, etc.)
· Solids alone or mixed with urine
· Amount of waste feed
· Contamination with bedding materials, rainwater, soil, etc.
· Method and period of storage

We are monograstrics. We are fed a high quality diet and my waste is high in nutrients.


Monograstrics


I am a ruminant. I am given a diet low in nutrients and my waste is low in nutrients. But I am cheap to feed.

MISCELLANEOUS FACTS

· Young livestock tend to feed on diets higher in protein so their wastes has more nitrogen and is better as a pond input.

· Ruminant feces contain high levels of carbon relative to nitrogen and discolor the water. Generally used alone, they give low-fish yields. Consider use of urine as it contains a better balance of nutrients.

· Laying hens are fed different diets than broiler chickens and their waste is particularly high in phosphorus

TIPS FOR PROPER WASTE APPLICATION

· First application can be done about 1-2 weeks before fish stocking to produce natural food FOR immediate fish consumption.

· Apply or load manure after sunrise (about mid-morning).

· Maintain a regular schedule or routine of application.

· Make sure that fresh water is available for flushing in case of DO depletion.

· During pond preparation, scrape off 1-2 inches of the pond bottom soil. This can SEVE as an excellent fertilizer for vegetables.

WATER QUALITY MANAGEMENT

Too much manure when loaded in fish ponds can cause dissolved oxygen (DO) depletion resulting to fish moralities. When manure loading is excessively high, too much decomposition occurs; thus, the biological oxygen demand (BOD) is high, using up the available DO.

Causes of and possible remedies for different water quality problems.

DISSOLVED OXYGEN INTO THE WATER

DISSOLVED OXYGEN USED UP IN WATER

OBSERVATIONS

CAUSES

POSSIBLE REMEDIES

Phytoplankton

Other

Phytoplankton

Other




0000
0000
0000

+ 0000 >

0000

+ 0000

green water; little surface scum; active fish behavior.

no problem.


0000
0000

+ 0000 <

0000
0

+ 0000
000

cloudy water; fish appear hungry

stocking density of fish to high

harvest some fish; add more fertilizer

0000
0000
00

+ 0 >

0000
0000

+ 0000

deep ponds; high dikes surrounded by trees

no wind-caused turbulence poor water circulation

agitation during critical periods remove wind breakers; keep water level high

0000
0000
0000
000

+ 0000

0000
0000
0000
0000
00

+0000

very green; surface scum gas bubbles

overabundance of stocking density

agitate during critical periods; add quik limite to precipitate scum; add fertilizer to stimulate growth of new plankton but afterwards ,reduce overall nutrients inputs; maintain fish at higher stocking density and/or release plankton eating fish

0000
000

+ 00

0000
0000
0

+ 0000

cloudy, still weather.

low light intensity; no natural agitation of water surface

agitation add fresh water;harvest some of the fish

0000
00

+ 0000 <

0000
0000
0

+ 0000

brown, discolored water; gas bubbles; pungent odor

overuse of poor quality manure.

use less manure and more inorganic

1 Phytoplanktons (produce dissolved oxygen during daytime but consume it at night.
2 Another source of dissolved oxygen in a static water is diffusion of atmospheric oxygen.

INDICATORS OF LOW DO

1. When plenty of fish are on the water surface gasping for air.


ater surface gasping for air

2. When air or gas bubles are observed in the water.


Gas bubles are observed in the water

3. The pond water is brownish or grayish.
4. The pond water swells pungent.

WHAT TO DO WHEN DO IS LOW

1. Stop manure bading.

2. Add fresh water into the pond. While doing so, drain water off the pond bottom.

3. Stir the pond water by striking the water surface with tree branches or other appropriate materials; row repeatedly across the pond.

4. Make provisions for flow-through system (if water is readily available).

5. Use mechanical aerators (l available).

WAYS TO MEASURE WATER TRANSPARENCY (OR TURBIDITY)


Use of a Secchie disc:

The disc is lowered into the water from a calibrated rope. If it disappears within a depth < 30 cm, the water is turbid.


Using one's hand:

With the hand strecthed forward, cup the palm and bend K towards you. in this position, slowly dip the hand into the water until the palm becomes invisible Transparency is expressed, the distance siltfrom the wrist to the end of the water mark on the arm.

if the water is turbid because of suspended sedimentary particles, spread over the pond surface chopped rice straw or hay, allowing them to settle at the pond bottom together with the silt practices.

CAUTION: Too much decomposing hay can also deplete dissolved oxygen.

pH or hydrogen ion concentration determines whether the water is acidic or alkaline. Highly acidic water (4 or balow) can result to fish kills.

METHODS TO MEASURE pH

Use of equipament as: litmus paper; pH meter; Hack kit

Practical method:

Testing the water: if water tastes sour, K is acidic. Knowing the water source: acidic water comes from swamps, bogs or water from stagnant areas.

WHAT TO DO

· Stop manure loading.
· Apply lime.

Hydrogen sulfide is a poisonous gas emitted from the pond bottom as a result of decaying and decomposing organic matter:

WAYS OF KNOWING THE PRESENCE OF HYDROGEN SULFIDE

· Emission of unpleasant odor resembling that of a rotten hard-boiled egg.
· Presence of dead fish like gobies

WHAT TO DO

Drain pond and dry pond bottom for 1 -2 weeks.

· Agitate the pond water.
· Add fresh water.
· Regulate or stop manure loading.

FISH HARVESTING METHODS TO REMOVE OFF FLAVOR

Off-flavor or muddy taste of fish harvested in manure-loaded ponds can be a serious problem if fish farmers do not follow the proper harvesting procedures. People will not buy nor eat the fish with off-flavor or muddy taste.


Fish harvesting

SUGGESTED PROCEDURES

1. Stop manure loading or delivery to the fish pond at least two days before harvesting.

2. Partialiy drain the Pond leaving about 40-50 cm water depth.

3. Harvest fish by seining before draining the pond totally. This will minimize fish mortality and the murky odor of fish associated with muddied water.

4. Transfer fish to a net enclosure installed In a pond with clean water or in holding tanks with running water and hold the fish for at least 4-6 hour..

5. Sell fish live or fresh.


Fish harvesting fish harvesting A


Fish harvesting fish harvesting B

Prepared by: RUBEN SEVILLEJA,JOSETORRES,JOHN SOLLOWS &DAVID LITTLE

FARMER-PROVENINTEGRATED AGRICULTURE-AQUACULTURE:
A TECHNOLOGY INFORMATION KIT(II RR -ICLARM)

Sewage-fed fish

Sewage is a rich nutrient resource, cheaply available around big towns and cities. It can be well-utilized for fertilizing paddies, fish ponds and horticultural crops. Waste utilization through recycling also helps in maintaining a clean environment. This paper is based on existent practices in Eastern India.


Rice-fish/prawns

In areas where irrigation facilities are not available, a second crop of rice is possible by construction water storage structures within the field. These could be in the form of lateral, central or marginal trenches or unilateral/bilateral ponds which are also utilized for aquaculture. Based on the input requirements for a 0.4 ha field, the following methods are adopted:


Raise the peripheral dikes by digging a perimeter trench (3 m wide x 1.5 m deep) or a lateral pond. If necessary, inlets and outlets are provided and guarded with meshed screens.


Fill the trench with sewage water to a level of 1 5-20 cm

Deep water paddy (CN 570, 652; NC 487 or 492) is sown directly after the first monsoon shower.


When water level in the trench is- about 60-70 cm, stock about 400 mature (1.5-2 g) mole (Amblypharyngodon mole) together with 8,000 bata (Labeo bata) having an average weight of 2g. As soon as 3-4 g prawn (Macrobrachium rosenbergil) are available, 2000 juveniles are also stocked.

The fish and prawn move about the field when the water level in the trench rises and covers the paddy.


The water level in the field and the trench falls with the end of monsoon. The paddy ripens by November/December and about 560 kg are harvested from the field in 150 days. The fish and prawn continue to grow in the trench.

Utilize the water in the trench for raising a second crop of rice. Fertilize it by taking in sewage to a level of about 10 cm each month from December to February. A low-level dike Is constructed all around to maintain a 10-15 cm water level in the paddy field.


The field is fertilized with sewage and seedlings of high-yielding varieties (Ratna or IET 4094) are transplanted in January.

Sewage fertilization is repeated when the seedlings have taken roots and again during the flowering stage. The fields are irrigated regularly and the water level maintained until the rice is mature. Pesticides are used only when necessary.

A partial harvest of the prawns (50 g), bata (20 g), mole (20 9) is made.

The paddy is harvested by April with a yield of about 2.0- 2.4 t.

The fishes are finally harvested by the end of April or early May. The total fish harvest is about 112 kg bata, 50 kg prawns and 45-50 mole.

ADVANTAGES

1. The second rice crop contributes to additional food production,-- employment and income generation.
2. Fish crop provides a rich protein food of high market value and adds considerably to the farmer' income.

LIMITATIONS

1. Trench/pond construction is useful only in water-retentive soils.
2. Difficulties in fish seed transport, if away from the main road.

Rupee budget for rice-fish-prawn culture in a 0.4-ha unit.

COSTS

Rs

For first (Kharif) crop


Rice seed (44 kg at Rs 3.50/kg)

154

Labor (20 man-days for ploughing, sowing, harvesting and thrashing at Rs 18/day)

360

For second (boro) crop


Rice seed (32 kg at Rs 3.50/kg.)

112

Labor (44 man-days for cleaning, transplantation,harvesting, etc.)

792

Pesticides

80

Fish Seed and Transport

2,500

Total Costs

3,998

INCOME


Sale of first paddy crop (560 kg at Rs 2.50/kg)

1,440

Sale of second paddy crop (2240 kg at Rs 2.50/kg)

5,600

Sale of 210 kg fish/prawn

6,240

Total Income

13,284

Balance

9,280

1 US$ = 25.50 Rs


Horticulture-fish

The utilization of sewage for aquaculture and horticulture results in high yields and economizes on fertilizer and feed costs, resulting in higher profits. Based on the input requirements for a 0.4 ha pond, the following procedure is recommended:


Broadcast about 200 kg of quicklime over the entire pond surface after it Is drained and dried for about 10-15 days.


Load the pond with 30 cm of sewage in early June which gets diluted with rain water and filled up to a level of 1.2-1.3 m by early July.

Stock with 3000 fingerlings of six species (catla 15, silver carp 25, rohu 25, grass carp 5, mrigal 20 and common carp 10) or 2000 fingerlings of three species (catla 40, rohu 30, mrigal 30).


Use the dikes (500-1000 sq m of land around the pond bank) for growing vegetables, beginning with monsoon crops, followed by winter and then summer crops. Each crop is harvested as soon as it is ready. About 1500 kg of vegetables are harvested from 500 sq m of dikes.

A wide range of vegetables can be planted: okra, eggplant, cucurbit gourds, cabbage, cauliflowers, potato, radish, tomato, onion and leafy vegetables like Amaranthus, Ipomoea, fenugreek, spinach, etc., are raised in simple mixed or multiple cropping.


Load the pond with sewage effluence once a month to the extent of one-fourth or one-fifth of the water level.

Feed all waste leaves to the grass carp in the pond; 80 kg of leaves give about 1 kg of fish.

The pond is netted every 15 days and marketable fish is harvested. A total of 2400 kg of fish can be harvested from the pond.

ADVANTAGES

1. Waste utilization/recycling of domestic sewage brings about a reduction in biochemical oxygen demand/bacterial load before releasing in streams.

2. High-stocking densities and high-yield rates, especially of plankton feeders as well as detritus feeders, are possible.

3. Low-cost fish/vegetable production.

DISADVANTAGES

1. Cope pod parasites due to high organic load cause moralities
2. Sudden fall in oxygen level owing to cloudy weather or heavy intake also results in moralities.

Rupee budget for vegetable production on a 1000 sq m plot on the pond banks.

Vegetable

Yield (kg)

Production Cost

Sale

Net income

Potato

2,000

1,200

2,500

1,300

Tomato

2,000

1,000

3,000

2,000

Brinjal

2,500

1,000

3,000

2,000

Chili

200 (dry)

1,200

2,800

1,600

Note: About 25 different kinds of vegetables are grown in single/mixed or multiple cropping and an average production of 3,000 kg valued and Rs 7,260 obtained. The cost of production being Rs 5,400 a net profit of Rs 1,860 is taken by farmers. In small farms, the farmer himself works as labor which accounts for 60% of the total production costs; hence, he nets out an income of Rs 1,860 + Rs 3,240 = Rs 5,100 or US $ 204.00.

Prepared by: S.D. TRIPATHI & B.K. SHARMA

FARMER-PROVEN INTEGRATED AGRICULTURE-AQUACULTURE
A TECHNOLOGY INFORMATION KIT (IIRR-ICLARM)

Biogas slurry in fish culture

Cowdung is commonly used as a fertilizer for fish ponds in India but fish production is limited to 15002000 kg/ha. These yields can, however, be more than doubled if the dung is first fed to a biogas plant and the digested slurry then used instead of the raw dung. The following methodology for a 0.4 ha pond exemplifies the technology.


Figure

1. Prepare the pond using the urea-bleaching powder

· method or by draining-drying in June.

2. Stock the pond with 2000 (5-8 9) fingerlings of six Asiatic carps: catla 20, rohu 25, mrigal 20, silver carp 20, grass carp 5 and common carp 10.

3. Fertilize the pond daily with 30 litres of biogas slurry. The slurry is rich in nitrogen and phosphorus, and is free from toxic gases which are produced when cowdung decomposes in ponds.

Excess slurry is used for the field while the gas is used both in the kitchen and for lighting the house.

The slurry is not applied on a cloudy day or when the fish come to the surface gulping air.

4. Surface feeders will be about 1 kg in six months. All marketable fish are then harvested every two months and replenished with an equal number of fingerlings. A total of 2000 kg of fish is obtained using biogas slurry as against 800 kg if raw cowdung were used.

ADVANTAGES

· Saving on inorganic fertilizers and feed (60% of operation costs).

· Environment-friendly—no oxygen demand.

· Saving on fuel and electricity.

· Cooking with biogas removes drudgery of womenfolk and helps in keeping the kitchen and environment clean.

LIMITATION

· Slurry/gas production is poor during cloudy days or when temperatures are low.

Biogas slurry.babed fish culture on a 0.4 ha pond.

Operational Expenses:

Rs

Cost of pond preparation

800

Cost of seed

400

Transport

1 00

Imputed cost of biogas plant (2 units, ddpreciation vain. On5-year life span)

2000

Lime (80 kg)

400

Netting charges

500

Total

4,200

Receipts:


Sale of 2000 kg fish at Rs 15/kg

30,000

Net income

25,800

Note: 1 U$ = 25.50 Rs

Plant sources of feed for fish

AQUATIC PLANTS

In India, TRAPA (Trapa bispinossa) and makhana (Euryale ferox) are two seasonal, aquatic cash crops which are grown extsosively In Madhya Pradesh and Bihar, respectively. While the environment is not congenial tar Indian carps, common carp goes well with trapa and airbreathing fishes with makhana tagged en the Input requirements for a 0.4 ha pond, the procedures to be adapted en given below:


Trapa bispinosa

1. Transplant trapa seedlings In May/June in a perennial pond. These plants make use of the

- available organic matter for their growth.

2. Stock 800 (50 g) common carp fingerings In September- October.

3. Trapa l fruits ripen in winter and are harvested from November to January. Aproduction of 3 4 tons of fruits is obtained.

4. Fish are harvests in April/May when 750-1000 g tish are available. A total of 400-500 kg fish are harvested


Euryale Ferox

1. The seeds sprout in February and the leaves cover the pond fully by May/June.

2. The plants start fruiting by August and burst in October, scattering the seeds at the pond bottom which are collected by scanning the bottom mud.

3. Stock 1,200 (8-10 g) air-breathing fishes (Clarlas batrachus) in November and harvest by April, when about 500 kg of fish can be obtained.


Napier grass.

Besides aquatic vegetation' such ' as Hydrilla, Ottella, Potamogeton, etc., green grass has a great role in feeding grass carp. Hybrid rapier, once sown on pond bank, can be cropped continuously for five years, needing little irrigation during summer. A new system utilizing aquatic vegetation/green grass alone for fish production gives high yields at very low costs. It is labor-intensive and highly suitable for small, shallow ponds (0.06 - 0.15 ha). Based on input requirements for a 0.1 ha pond, the methods to be followed'are given below:

1. Prepare the pond in May/June using urea-bleaching powder method or by draining, It a source of water for filling the pond is available.


Prepare the pond in May/June

2. Seven to ten days later, stock the pond with 200 (5060 9) grass carp. Feed them to satiation (system of feeding ad libitum: fish 'are satiated when they have stopped feeding and there are still some feed material' left lying about) with Hydrilla.- Within about a week, the pond is also stocked with 40 each of catla, rohu, mrigal, silver carp and common carp (5-8 g). Grass carp is gradually - weaned from Hydrilla to napier grass.

3. Feeding is done regularly to satiation.


Feeding is done regularly

4. Silver carp, catla and common carp will be the first to attain a weight of 1 kg each. From the fifth or sixth month onward, these are harvested one after another. Replenish the harvested fish with an equal number of fingerlings.

5.Hybrid napier is planted at 1 root slip/sq m and manured with 2.5 t farmyard manure/1000 sq m.

Irrigation is done at 10-15 day intervals. The grass is cut after 75 days, followed by 45-day intervals. About 10 cuts can be taken from each plant. A production of 12-15 t napier from 1000 sq m is taken. About 2000 sq m land area will produce enough napier to feed the fish in a 0.1 ha pond. This means that to provide sufficient grass to feed the fish, twice the pond area is needed for growing rapier.

6. About 400 kg of fish can be harvested from the pond in the course of one full year.

ADVANTAGES

· Utilization of rapier/weeds for fish production at no cost.
· Utilization of pond resource for fish production in trapa/makhana ponds.
· Additional income and employment generation.

LlMITATIONS

· Non-availability of large-eked grass carp and their transport
· As large quantities of grass Is required, napier/weed integration is possible in small ponds only.

Prepared by: S.D. TRIPATHI & B.K. SHARMA

FARMER-PROVEN INTEGRATED AGRICULTURE-AQUACULTURE
A TECHNOLOGY INFORMATION KIT (IIRR-ICLARM)