Fish based integrated farming system for higher income
- Part 1 -

Ch Basudha Devi *

Asia has been the cradle of integrated crop-livestock-fish farming systems, which have evolved since the inception of human civilization particularly when human settlements started moving inland leaving the river banks. Though there are several successful practices of integrated fish farming in Asian countries, including Indian, the system of farming using synergizing scientific integration of agriculture, aquaculture and livestock farming are not yet widespread in the region.

Further, large-scale integration of carp culture with irrigation and sewage utilization are to be viewed-seriously, both for economic and ecological reasons (Sinha, 1979). Integrated fish fanning is a system of producing fish in combination with other agricultural/livestock farming fish pond.

The farming subcomponents e. g. fish, crop and livestock are linked to each other in such a way that the by-products/wastes from one sub component become the valuable inputs to another sub-component and thus ensuring total utilization of land and water resources of the farm resulting in maximum and diversified farm output with minimum financial and labour costs.

In a proper fish, crop and livestock integrated farming system, the possible inter sub-system interactions are - excreta and waste feed from livestock sub-system acting as manure and feed for fish as well as for crop land. Byproduct/wastes of crop can be used as feed and manure for the fish pond and as feed for livestock.

Nutrient rich bottom silt and water of of fertilizers for the crop land. It thus appears that the different sub-systems in an integrated system are beneficially inter-linked to each other in a limited area, minimizing the production costs but resulting in a diversified output viz. fish, meat, eggs, vegetables, fruits, fuel wood and fodder which are the basic need of a farm family Most integrated fish based inteerated farming systems use low levels of inputs and fall within the type of aquaculture called semi-intensive.

This means less reliance on heavy feed and fertilized inputs, lower densities of farmed organisms and. therefore, less chances of causing serious pollution and disease risks than more intensive, feedlot-type systems. This is important as i is the high output of the foodstuffs nec-systems that create environmental pollution. Semi-intensive systems in synergy with agriculture (crop-livestock-fish integrated farming) capitalize on in situ, vitamin and protein natural aquatic feeds, which obviate the need for expensive feed components.

Semi-intensive freshwater ponds usually have few environmental effects other than their occupation of former natural habitats. In the tropics, where there is fast turnover of organic waste loading, their effluents and excavated soils usually enhance the productivity of adjacent waters and lands and avoid over enrichment.

Most of the farmers in India have limited spaces for taking up additional and diversified farming activities. Integrated fish farming on the other hand offers opportunity for taking ties with optimum utilization of available land space for food production, thus increasing household income of small farmers.

Fish-livestock production in combination with planted crops on pond dykes could be a workable pattern of an integrated system. The inter-linkmg is easy: the farm animal produces organic manure for fertilization of agricultural land and fish pond - the crops and plants provide food for animals, fish and man - the nutrient rich pond humus can provide fertilizer to the crop land.

Integrated fish farming can be broadly classified into two:

1. Agriculture-fish and
2. Livestock-fish systems.

Agriculture-fish integration systems include rice-fish integration, horticulture-fish Livestock-fish system includes cattle-fish system, pig-fish system, poultry-fish system, duck-fish system, goat-fish system, rabbit-fish system. In the present effort enhancing fish production under various fish based integrated farming models for higher income generation is being discussed.

FISH-CUM-RICE FARMING

Rice and fish culture has been a tradition in southeast Asia including Manipur for over 2000 years. Rice is presently grown in 113 countries. Rice farming also offers a suitable environment for the culture of fish and other aquatic organisms. This rice-based farming system contributes towards food security and poverty alleviation of the country

Notable changes have taken place in pest management in rice fanning, and in fish seed production and availability, making this a particularly relevant moment for emphasizing the importance of rice-fish farming. 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 rice 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 @ 5,000 -10,000 fingerling ha-1.

FISH-CUM-TERRESTRIAL CROP FARMING

All or most parts of the crops planted in the fodder crop field and comer plots on the pond dykes and slopes are used as green fodder for the fish and as fertilizers for the ponds. This is the most popular pattern in fish cum crop integration.

Crop variety: Crop that are palatable to the fish, rich in nutrition, resistant to disease, easy to manage and have well-developed roots to protect the slope should be used. If the crop serves as manure, it should decompose easily. High value crops like chillies, carrot, broccoli, onion, garlic brinjal, beans etc, can be grown in the pond dykes.

In upland an colder area, fruits like kiwi, passion fruit etc can be grown. Banana, papaya, cassava plants, leguminous plants like parkia etc are suitable to be planted at the outermost dyke of fish farm.

Aquaculture can provide large amounts of silt and fertile water for agriculture and land on fish farms have much agricultural potential. The average pond dyke is 3 m wide with a slope gradient of 1:1.5 to 1:3. The mean area of a fish pond is 0.25-0.5 ha. The average ratio of arable land area (pond dyke and slope) to water surface area is 1:5.

There is more arable land before May, when the water level in the pond is low. With an extra forage field attacked to fish pond in addition, all the areas already available, the ratio of arable land area to water surface area could reach 1:2 or even higher Aquatic plants can also be planted on scattered, unused surface.

It is necessary and feasible to integrate fish farming with crop production to fully utilize pond silt, arable land, and water surface. As a result, the demand for fish feeds can be wholly or partially satisfied.

FISH-CUM-LIVESTOCK FARMING

The only objective of integrated livestock fish farming is to produce an optimum level of phytoplankton, zooplankton and bacteria, which are pro-tein-rich natural feed for fish from livestock excreta. The suitable fish species for integrated fish farming system are those that able to filter feed plankton and bacteria from water.

The common filter feeders are carps and mixed feeders on algae-detritus are some species of tilapia. Tilapia can survive on low levels of dissolved oxygen than the carps.

Indigenous species like catla (Catlacatla), rohu (Labeorohita), mrigal (Cirrhinusmrigala) and kalbasu (Labeocalbasu) and the exotic varieties like grass carp (Ctenopharyngodon Idella), silver carp (Hypophthalmichthys molitrix) and common carp (Cyprinus carpio) are commonly used for composite fish culture.

ANIMAL WASTES IN INTEGRATED FISH FARMING

Animal wastes and waste feed particles which enter the food web of a pond ecosystem are utilized in several ways: [As a source of nutrients required for primary production;
[As nutrients and organic substrates for heterotrophic micro-organisms which in turn may be consumed directly by fish or by invertebrate fish food organisms;

Directly consumed by the fish.

A large number of farmers in rural areas are reluctant to handle and apply animal excreta in fish ponds. Some of them also hesitate to eat fished produced in integrated fish farms where fish consume fresh poultry manure directly. Generally, most of the ponds are built for serving various social functions such as raising foundations for houses, bathing, washing, cooking and even for drinking.

Adoption of integrated fish-livestock farming is not possible in many ponds, particularly in homestead ponds, because of the use of water for domestic purposes.

To be continued...