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Model Bankable Projects



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 Penaeusmonodon,Penaeusindicus,Metapenaeusdobsonii and Metapenaeusmonoceros.

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.


The paddy field is made ready for stocking and Penaeus monodon or Penaeus indicus are stocked @ 3 nos/sq.m


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


Complete harvesting can be carried out 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 (depending on the species). Harvested shrimps can be kept between layers of crushed ice before transporting the consignment to market.

Production & Income

The expected production for an area of 0.5 ha. is around 350 kg. The income from 0.5 ha. has been assessed to be Rs.87500/-.


Frozen shrimp contributes 70% by value and 30% by volume of our marine products exports. Japan, USA, European Union, South East Asia, China and the Middle East are the major markets for our shrimp. The shrimp catches from the wild are fast dwindling due to over exploitation and culture of shrimp is an alternative to increase shrimp production for export and also for local consumption.

Financial outlay

Details of the financial requirement for paddy cum shrimp culture in 0.5 ha. area have been indicated in Annexure I. The items and cost indicated under the model are indicative and not exhaustive. While preparing projects for financial assistance the costs have to be assessed taking into account actual field conditions. The projected capital cost for 0.5 ha. unit has been estimated to be Rs.67500 and operational cost for one crop to be Rs.51000.

Financial viability

The following assumptions have been made for working out the financial viability of the activity taking only aquaculture into account assuming that paddy cultivation was being done prior to taking up aquaculture and will also be continued after taking up aquaculture. The economics would remain unchanged for paddy, hence not taken into account for calculating economics and repayment.

1 Pond Size 0.5 ha
2 Culture Period 100 to 120 days
3 Stocking density 3 nos/sq.m
4 Survival


5 Size at harvest 35 gm.
6 Expected production 350 kg /0.5 ha
7 Crops per year One alternating with one paddy crop
8 Farm gate price Rs. 250 / kg

The financial analysis has been shown in Annexure III. The results of the analysis are


(i) NPW at 15% DF : Rs. 105092
(ii) BCR at 15% DF : 1.37:1

IRR is more than 50%

Margin money and bank loan

The farmer is expected to bring margin money out of his own resources. The rates of margin money stipulated are 5% for small farmers, 10% for medium farmers and 15% for other farmers.

Rate of Refinance

NABARD provides refinance assistance for paddy cum shrimp culture to commercial banks, cooperative banks and Regional Rural Banks. The rate of refinance is charged as fixed by NABARD from time to time. The long term investments under the above scheme can be disbursed only under schematic lending and cannot be booked under ARF.

Interest rate for ultimate borrowers

Banks are free to decide the rate of interest within the overall RBI guidelines. However, for working out the financial viability and bankability of the model project we have assumed the rate of interest as 12% per annum.

Interest rate for refinance from NABARD

As per the policycirculars of NABARD issued from time to time.

Repayment Period

Repayment of bank loan is possible in 8 years with no moratorium


Banks may take a decision as per RBI guidelines.

Special Conditions

1. Clearance from National Aquaculture Authority for undertaking the activity.
2. Water level to be maintained at 1.5 m, with a minimum of 1.2 m water column.
3. Stocking should not exceed 10 nos/sq.m
4. Seed should be PCR tested.
5. Site feasibility and intake water quality to be ascertained from competent agency like MPEDA / BFDA.
6. Effluent treatment units for WSA of 5 ha. and above.

Annexure - I

Estimated financial outlay for paddy cum shrimp culture in 0.5 ha water area

Capital Cost

Items of Investment Units Quantum Rate (Rs.) Total
1 Modification of the paddy field by digging perimeter canal, trenches, bund construction and compacting & consolidation Cum 1,200 25 30000
2 Inlet / outlet sluices (lump sum) Nos 2 6250 12500
3 Cost of 3 HP Diesel pump set with accessories and pump shed     LS 20000
4 Nets and other items     LS 2000
5 Miscellaneous     LS 3000
  Total       67500

Operational Cost for one crop

  Units Quantum Rate (Rs.) Total
1 Seed Nos 15000 0.50 7500
2 Removal of predator     LS 500
3 Fertilizers and liming     LS 1000
4 Diesel cost (for pump)     LS 2500
5 Feed Kg 700 Rs 45/kg 31500
6 Pump set maintenance     LS 3000
7 Harvesting and marketing charges     LS 2500
8 Miscellaneous       2500
  Total       51000

Annexure II

Production & Income

1 Survival


2 Average weight at harvest (gms) 35
3 Total production (kg) 350
4 Farm gate price (Rs) 250
5 Number of crops per annum 1
6 Income per crop (Rs.) 87500

Annexure III

Financial Analysis

(Amt. in Rs.)

Items Years
  1 2 3 4 5 6 7 8
Capital cost 67500              
Recurring cost 51000 51000 51000 51000 51000 51000 51000 51000
Total cost 118500 51000 51000 51000 51000 51000 51000 51000
Income 87500 87500 87500 87500 87500 87500 87500 87500
Net Benefits -31000 36500 36500 36500 36500 36500 36500 36500
PW of costs @ 15% DF 103043 38563 33533 29159 25356 22049 19173 16672
PW of benefits @ 15% DF 76087 66163 57533 50028 43503 37829 32894 28604
NPW 105092              
BCR 1.37:1              
IRR >50%              

Annexure IV

Repayment Schedule

Capital cost :Rs. 67500
Operational cost :Rs. 51000
Total financial outlay :Rs. 118500
Margin money @ 5% of TFO :Rs. 5925
Total loan amount :Rs. 112575
Say :Rs. 112600

(Amt. in Rs.)

Year Principal Gross surplus Interest

@ 12%

Repayment Net Surplus
Principal Interest Total
1 112600 36500 13512 14000 13512 27512 8988
2 98600 36500 11832 14000 11832 25832 10668
3 84600 36500 10152 14000 10152 24152 12348
4 70600 36500 8472 14000 8472 22472 14028
5 56600 36500 6792 14000 6792 20792 15708
6 42600 36500 5112 14000 5112 19112 17388
7 28600 36500 3432 14000 3432 17432 19068
8 14600 36500 1752 14600 1752 16352 20148

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