Water Seeded RiceThe practice of water seeding rice originated and is still followed, in parts of Asia, including India, Sri Lanka, Malaysia and Thailand. It is widely practiced in the United States, southern Europe, Russia and Australia.
For water seeding, precise water control is must, and more seeds are required than for the transplant method. Good seed viability is essential. Oxygen deficiency does not appear to be limiting factor in stand establishment of rice in water seeded rice.
Satisfactory drainage is necessary in areas subject to flooding. Proper land preparation and leveling ensure the uniform spread of water during irrigation and facilitate easy drainage when required during crop establishment.
With inadequate water control and poor drainage direct seeding may run risk of early stage submerge and crop failure.
There are three basic water seeding systems:
- Continuous flooding
- Pinpoint flooding
- Delayed flooding
Water seeding is preferred over dry seeding in certain rice producing regions, due to factors such as , red rice suppression, rapid stand establishment, and tradition.
In southwestern Louisiana, water seeding is the most extensive planting method used because significant rice hectarage is severely infected with red rice.
Control or suppression of red rice is highly dependent on the water seeding system used.
Water seeded rice is the major system of rice culture in California. It is intensively managed with varying external inputs of farm equipment, fertilizers and pesticides.
The usual practice in California is to soak the seed for 18-24 hours , drain for 24-48 hours and seed by airplane into field flooded to a depth of 7.5 – 15 cm.
Continuous flooding is the primary cultural system in California. The system provides excellent weed control, especially when coupled with herbicides. Design of most irrigation systems with continuous flooding in California includes floodwater recirculation to minimize pesticide movement to public waterways.
Pinpoint flooding is the most popular water seeding practice is Louisiana, especially in the southwestern area. In this system, fields are flooded, seeds are sown aerially and then fields are drained within 1 to 3 days. The floodwater is removed for a very brief period of time, generally 3 to 5 days and a shallow, permanent flood is then established.
The brief drainage period in this system encourages better seeding anchorage the typically occurs with continuous flooding. A disadvantage with continuous flooding can be poor root anchorage, which occurs with varieties that possess poor seedling vigor.
In water seeded delayed flooding system, the basic difference in water management form continuous and pinpoint is the extended drainage period after seeding. The permanent flood is not established until 15 to 20 days after emergence. Adequate moisture for seedling growth and establishment is maintained by rainfall or flush irrigation.
Water Seeded Rice
