Source of Technology
A modified technology of the Department of Agriculture, Rice + Fish Farming System was launched in 1979. In the year 2001, an on-farm research on rice and prawn farming was initially introduced in the upland areas of two barangays Oples and Taytay, Nagcarlan, Laguna.
Rice-prawn culture is considered to be an ideal method in maximizing land use through rice and prawn production. It requires farmers to devote 10% of the total area for pond refuge for prawn and the remaining 90% for rice.
The technology offers an improved alternative livelihood for the farmers since prawn has a high market value commodity (P300-500/ kg).
Source of Post Larvae (PL)
Post larvae prawn comes from BFAR National Centers particularly the BFAR-Technology Center, Binloc Fishery Station, Bonuan,
Pangasinan and the BFAR-National Freshwater Fisheries Technology Center, Muñoz, Nueva Ecija and from the private sectors. Recently, BFAR IV-A established a prawn hatchery in Tagkawayan, Quezon for commercialization to cater to the post larvae needs of the prawn operators.
A. Pond Preparation
- Clear the area intended for prawn.
- Excavate the pond to the desired size.
- Dry the pond bottom for a week in order to eliminate predators.
- Place fine mesh nets (screen) in every opening (inlet and outlet) of the pond. This will prevent the entrance of predators and will facilitate proper and easy water management.
- Maintain good water quality and depth of one meter. Source of water includes natural spring, pump and irrigation.
- Fertilize pond using chicken manure at 150g/ m2.
B. Artificial Shelter
An improvised shelter to serve as hiding place for the newly molted prawn should be provided. The following different materials can be used as shelter:
- Cut old nets into square shape (10cm x 10cm): Add weights (small stone) at the center and tie with rubber band. The old nets can be washed to remove dirt and algae.
- Arrange pipes of 10 cm long into pyramid shape. Tie with wire or any water resistant material. Sealant can also be used.
- Dried twigs made of bamboo and camatsile are considered as one of the best shelters for prawns. Aside from being a refuge, it makes sampling activity easy and manageable by just lifting the twigs and scooping the prawns attached to the shelters. This method will lessen stress and mortality to the prawns.
- Coconut leaves are one of the readily available shelters for prawn. After cutting, it can be placed directly into the pond. Coconut leaves should be changed weekly to maintain the good water quality of the pond.
C. Feeds and Feeding (Size – % Body Wt – Frequency)
- Post larvae – 5 – 2x daily
- Juvenile – 3 – 2x daily
- Adult – 2 – 2x daily
Commercial feeds in form of sinker pellet can be given to prawn based on their body weight requirement. For the first two months, feeding can be done by the use of a feeding tray while for the succeeding months, by broadcast method.
D. Stocking of Prawn
- Prawns are stocked intensively at 10 pieces per square meter. It is done early in the morning or late in the afternoon to avoid stress and mortality.
- Plastic bags with prawns are kept floating in the water from 15-30 minutes to acclimatize them to the condition of the water in the pond. After acclimatization, prawns are released slowly in the pond.
E. Monthly Sampling of Prawn
Random sampling is conducted monthly to determine the growth and to adjust the feeding ration. During sampling, prawns are caught and collected by scooping at the edges and under the shelters. After sampling, prawns are returned to the pond.
Prawns are ready for harvest after six months of culture. For a small pond area, complete pond draining is done and prawns are
hand-picked individually. However, for large ponds, casting of prawns for several times is done followed by complete draining. This will ensure that more live prawns are harvested and recovered in large quantity. Total harvest are weighed and recorded.
Prospectus of 1,000 sq.m. Rice-Prawn Farming System
100 sq.m. Prawn Pond
- 1,000 pcs prawn post larva @P2.50/pc = P2,500.00
- Feeds = 2,308.00
- Caretaker’s fee = 2,500.00
- Gasoline = 500.00
- Total P7,808.00
Gross Income: 40 kgs of marketable prawn sold at P350/kg = P14,000.00
Net Income: P6,192.00
900 sq.m. Rice Area
- Furrowing = P920.00
- Seeding = 190.00
- Transplanting = 390.00
- Fertilizer = 480.00
- Total P1,980.00
Gross Income: 8.25 sacks of palay @50kg/sack sold at P7.50/kg = P3,093.75
Net Income: P1,113.75
Total Income for Rice-Prawn Farming System (1,000 sq.m.)
- Prawn = P14,000.00
- Rice = 3,093.75
- Total P17,093.75
- Prawn = P7,808.00
- Rice = 3,980.00
- Total P9,788.00
Net Income: P7,305.75
For more information, please contact:
BFAR Region 4A RFRDC Freshwater Fisheries Research Station
Bambang, Los Baños, Laguna