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Wet bed nursery

Wet Nursery

This is widely used in areas where water is abundant. The seed bed is usually prepared 25 to 35 days before trans­planting. Steps involved in raising wet bed seedlings are as follows

• Land where both irrigation and drainage can be controlled should be selected for seed bed. The land should be fertile and free of excess salts or other soil problems.
• The seed bed area is ploughed twice either in dry or wet conditions and then puddle by giving two or three more ploughings. After 10 days, the field is again ploughed twice and leveled.
•  When the field is brought to fine soft puddle condition, raised beds (4 - 5 cm high) of 1.2 m wide and of convenient length with 45 cm channel all around are constructed. Raised beds are not necessary in areas where water­ logging is not a problem. Excess water is drained off to maintain a water level just sufficient to cover the soil. The surface of the seed bed is so levelled that there is gradual inclination toward both sides to facilitate drainage of water during the first few days.
• For each 100 m² area of nursery bed, provide 1 kg N, 0.4 kg P₂O₅ and 0.5 kg K₂O. Double the P₂O₅ application in locations where cool temperatures retard the growth of seedlings. The fertilizers are mixed with soil before sowing.
• Sow (broadcast) pre-germinated seeds (soak the seeds for 24 hours, incubate in warm moist conditions for 36-48 hours until germination) on a drained bed at the rate of 50 - 70 g (unsoaked weight basis) per square meter depending upon the size of the seed. If seeds are sown too closely seedlings will be weak. It will be also more difficult to pull seedlings and there will be more chances of injury to the long roots of adjacent seedlings.
• Keep the beds moist for the first few days. Do not flood the beds. When the seedlings are about 2 cm high, keep the beds submerged in a shallow layer of water.
• Top dress the seed beds with 0.3 kg to 0.6 kg N per 100 square meter area, 6 days before transplanting.
• Appropriate control measures should be taken for pests and diseases in the nursery if they occur.

Puddling in Paddy nursery

Procedure for pulling the seedlings out of seed bed:

Seedlings are ready for transplanting from 20 to 25 days after sowing. Seedlings more than 30 days old when transplant­ed recover more slowly than younger seedlings, especially if they suffer stem and root injury. Seedlings less than 20 days old are too short to be pulled from the soil. The procedure is as follows:

• Two to three seedlings are grasped at a time.
• The seedlings are held between the thumb and forefingers, and as close to the base as possible.
• They are pulled gently and easily at an angle of about 30° on the horizon.
• If too much mud sticks to roots, it is washed by shaking the roots in water. The plant roots should not be thrashed against feet or any object to remove mud as this will injure the plants.
• Convenient size of seedling bundle (5 - 8 cm in diameter) is made by tying with any soft material may and the seedling should be protected from drying.

Raised seedbed preparation	Pre-germinated paddy seeds	Sowing of seeds

Advantages of Wet Bed Nursery:

• Less seed is required per unit area.
• It may be grown in any type of soil but the suita­bility will vary.
• Growth is quick with strong and sturdy seedlings. Number of seedlings per hill
• can be specified; there­fore seedlings are not wasted.
• It can withstand slight salinity.

Disadvantages of Wet Bed Nursery:

• Copious water supply is essential. This causes delay in transplanting.
• Seeds are easily carried away by rainwater if a heavy rain occurs shortly after sowing.
• Prepara­tion and care of seed bed and pulling of seedlings are laborious.
• It is difficult to arrest seedling growth.

• Seedlings cannot be kept longer in the nursery as they tend to tiller and produce nodes under the favorable conditions.
• It requires more space and this entails in loss of space where crops are standing.
• Seedlings cannot withstand drought.