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Rice cultivation

  1. Aug 30, 2010 #1
    In many Asian countries, particularly India, rice is grown in a way where rice seeds are first sown in one field, and then the seedlings are taken out to be transformed to a water flooded field. I have not witnessed the plantation personally. Why don't they simply sow the seeds and get the full crop without any seedlings transfer?

    The following videos illustrate what I'm saying:
    http://www.youtube.com/watch?v=i8a0_yw-mg0&feature=related (watch between 1.07-2.10)

    http://www.youtube.com/watch?v=ElYKKO82fpo&feature=related

    In a Wikipedia article on rice I found this:

    Environmental impacts

    In many countries where rice is the main cereal crop, rice cultivation is responsible for most of the methane emissions. Rice requires slightly more water to produce than other grains.

    As sea levels rise, rice will become more inclined to remain flooded for longer periods of time. Longer stays in water cuts the soil off from atmospheric oxygen and causes fermentation of organic matter in the soil. During the wet season, rice cannot hold the carbon in anaerobic conditions. The microbes in the soil convert the carbon into methane which is then released through the respiration of the rice plant or through diffusion of water.

    The red part seems to suggest that whenever soil is covered with water, fermentation of organic matter starts taking place even when there is no crop, such as rice, involved. What do you say on this?

    I couldn't understand the blue part. Please help me with it.
     
  2. jcsd
  3. Aug 30, 2010 #2

    Astronuc

    User Avatar

    Staff: Mentor

    One has to look at the specific area (fields and precipitation, and perhaps availability of irrigation).

    http://www.plantcultures.org/plants/rice_production__trade_cultivation.html [Broken]

    In some cases, seeds are sown and the paddies flooded, though they may remain shallow.

    In other cases, where significant rise in water level occurs, rice may be grown in deeper water, up to 5 m! Most other grains, corn, wheat, rye, oats, millet, . . . would not grown in 5 m of water. Certain rices are uniquely suited for such conditions.

    http://www.rice-trade.com/semi-dry-upland-cultivation.html [Broken]
    http://www.rice-trade.com/wet-lowland-cultivation.html [Broken]

    I'm not sure what the concern is.

    Of course, there are varieties of rice that can be grown in drier conditions. The use of ammonium sulfate can reduce methane production. Perhaps the local farmers use methods most suited to the local conditions and economics.

    On the othe hand, The SYSTEM of RICE INTENSIFICATION may offer an improved system.
    http://ciifad.cornell.edu/sri/ [Broken]
     
    Last edited by a moderator: May 4, 2017
  4. Aug 31, 2010 #3
    Um... Algae, anyone?
     
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