Alternate wetting and drying (AWD)--using less water to grow rice

00:06:27
https://www.youtube.com/watch?v=tfKWKfagfFs

Summary

TLDRThe video highlights the increasing water scarcity affecting rice cultivation, which is vital for half of the global population. It presents the alternate wetting and drying (AWD) technique as a solution to conserve water in irrigated rice fields. AWD involves alternating between flooding and drying the fields, allowing farmers to save water without compromising yield. The video details how to implement AWD using a field water tube to monitor water levels and provides guidelines for irrigation timing and fertilizer application. It stresses the need for community-level adoption of AWD to fully realize its benefits.

Takeaways

  • 💧 Water scarcity is a growing global issue.
  • 🌾 Rice is a major water consumer in agriculture.
  • 🔄 AWD helps save water in rice farming.
  • 📏 Safe AWD involves monitoring water levels.
  • 🌱 AWD can be implemented after transplanting rice.
  • 🧪 Fertilizer application is crucial during AWD.
  • 📊 Water savings of 15-25% are possible with AWD.
  • 🌍 Community adoption enhances AWD benefits.
  • 🛠️ Field water tubes are simple tools for farmers.
  • 🌿 AWD does not compromise rice yield.

Timeline

  • 00:00:00 - 00:06:27

    Water scarcity is becoming a global issue, particularly affecting rice production, which is vital for nearly half the world's population. To combat this, scientists have introduced the alternate wetting and drying (AWD) technique, which conserves water in rice cultivation by allowing fields to dry before being reflooded. This method, known as safe AWD, involves monitoring water levels using a field water tube and ensures that the water level drops to 15 cm below the soil surface before irrigation, preventing yield loss. Farmers can also apply nitrogen fertilizer effectively during this process. Although water savings may be modest (15-25%), there is no negative impact on yield. Farmers can further optimize water use by experimenting with deeper thresholds for irrigation. The field water tube, a simple tool made from local materials, aids in monitoring water levels, making AWD a practical solution for sustainable rice farming. However, the full benefits of AWD are realized when adopted at a community level.

Mind Map

Video Q&A

  • What is AWD?

    AWD stands for alternate wetting and drying, a technique to save water in rice cultivation.

  • How does AWD work?

    AWD alternates between flooding and drying rice fields to reduce water usage.

  • What is the safe AWD threshold?

    The safe AWD threshold is when the water level drops to 15 cm below the soil surface before reflooding.

  • What are the benefits of using AWD?

    AWD can save 15-25% water without reducing rice yield.

  • How can farmers monitor water levels in AWD?

    Farmers can use a field water tube to observe water levels in the soil.

  • When should AWD be implemented?

    AWD can start a few days after transplanting or when the rice is 10 cm tall.

  • What materials can be used for the field water tube?

    The tube can be made from plastic, bamboo, or other indigenous materials.

  • What is the importance of community adoption of AWD?

    Community-level adoption maximizes the benefits and water savings from AWD.

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  • 00:00:09
    [Music]
  • 00:00:16
    [Applause]
  • 00:00:19
    Across the globe, water is fast becoming
  • 00:00:22
    a precious commodity as more and more
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    people use water for the household,
  • 00:00:27
    industry, and agriculture.
  • 00:00:30
    Rice uses up the most amount of water in
  • 00:00:33
    agriculture with almost half of the
  • 00:00:36
    world's population depending on rice as
  • 00:00:38
    their staple food. By
  • 00:00:41
    2025, 15 to 20 million hectares of
  • 00:00:45
    irrigated rice fields may suffer from
  • 00:00:48
    water scarcity.
  • 00:00:50
    To address this problem, scientists have
  • 00:00:53
    developed a technique called alternate
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    wetting and drying or AWD, which uses
  • 00:00:59
    less water to grow rice. AWD is a
  • 00:01:03
    water-saving technology that lowland
  • 00:01:06
    rice farmers can apply to reduce water
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    use in irrigated
  • 00:01:11
    fields. In AWD, the rice field is
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    allowed to dry for a number of days
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    before being flooded again. Hence, the
  • 00:01:20
    field is alternately flooded and left
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    dry. The number of days that the field
  • 00:01:26
    can be left dry depends on the soil type
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    and other field
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    conditions. A practical way of applying
  • 00:01:36
    AWD is by observing the depth of water
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    in the field using a field water
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    tube. After irrigation, water level will
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    gradually decrease.
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    When the water level has dropped to 15
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    cm below the soil surface, the field
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    should be reflooded to a depth of 5
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    cm. Allowing the water in the field to
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    drop to 15 cm below the soil surface
  • 00:02:04
    before irrigating again is called safe
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    AWD.
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    The 15 cm limit will not cause any yield
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    decline since the roots of the rice
  • 00:02:14
    plants will be able to take up water
  • 00:02:17
    from the saturated soil and the perched
  • 00:02:20
    water level in the surface. The field
  • 00:02:23
    water tube helps farmers see the hidden
  • 00:02:25
    source of water.
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    Safe AWD irrigation can be started a few
  • 00:02:31
    days after transplanting or when the
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    directseed rice crop is already 10 cm
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    tall until first heading. When many
  • 00:02:41
    weeds are present in the early stages of
  • 00:02:43
    crop growth, safe AWD can be postponed
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    for 2 to 3 weeks until the weeds have
  • 00:02:49
    been suppressed by the ponded water.
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    Local fertilizer recommendations for
  • 00:02:55
    flooded rice can be used. Apply nitrogen
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    fertilizer preferably on the dry soil
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    just before
  • 00:03:05
    irrigation. A week before to a week
  • 00:03:07
    after the peak of flowering. Water
  • 00:03:10
    should be kept at a 5 cm depth to avoid
  • 00:03:13
    water stress which could result in
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    potentially severe yield
  • 00:03:18
    loss. After flowering and during grain
  • 00:03:22
    filling, apply safe AWD
  • 00:03:26
    again. In safe AWD, water savings may be
  • 00:03:31
    relatively small about 15 to 25% but
  • 00:03:35
    there is no yield penalty.
  • 00:03:38
    Once farmers are confident that safe AWD
  • 00:03:41
    does not reduce yield, they can
  • 00:03:43
    experiment by lowering the threshold
  • 00:03:46
    level to 20, 25, 30 cm depth or even
  • 00:03:50
    deeper before
  • 00:03:52
    [Music]
  • 00:03:55
    irrigation. The field water tube can be
  • 00:03:58
    made of a plastic pipe or bamboo or
  • 00:04:01
    other indigenous materials that will
  • 00:04:03
    help farmers see water below the soil.
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    Cut these materials to a 40 cm length
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    with a diameter of 15 cm or more to
  • 00:04:14
    easily see the water level inside the
  • 00:04:16
    tube. The bottom 20 cm length of the
  • 00:04:20
    tube should be drilled with holes on all
  • 00:04:23
    sides. Holes should have a diameter of
  • 00:04:26
    about 0.5 cm each and spaced about 2 cm
  • 00:04:31
    away from one another.
  • 00:04:33
    [Music]
  • 00:04:39
    The tube can be placed on the side of
  • 00:04:41
    the field close to the bond, but not
  • 00:04:44
    less than a meter away for easier
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    monitoring. Bury the tube vertically
  • 00:04:50
    into the soil so that 20 cm or half of
  • 00:04:53
    its length protrudes above the soil
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    surface. Take care not to penetrate
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    through the bottom of the plow pan or
  • 00:05:00
    hard pan, which is a dense layer of soil
  • 00:05:03
    that is largely resistant to water.
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    Remove the soil inside the tube so that
  • 00:05:08
    the bottom of the tube is
  • 00:05:11
    visible. Check that the water level
  • 00:05:13
    inside the tube is the same as that
  • 00:05:15
    outside the tube.
  • 00:05:19
    Alternate wetting and drying or AWD is
  • 00:05:23
    already a mature technology that can be
  • 00:05:25
    readily used by farmers. The field water
  • 00:05:29
    tube is a very simple tool that guides
  • 00:05:32
    farmers to effectively and efficiently
  • 00:05:34
    manage their limited irrigation water
  • 00:05:36
    for their rice crop.
  • 00:05:39
    However, farmers can only truly
  • 00:05:41
    appreciate the benefits and water
  • 00:05:44
    savings from AWD if adoption of this
  • 00:05:47
    promising technology is done at the
  • 00:05:49
    community or system level.
  • 00:05:56
    [Music]
Tags
  • water scarcity
  • rice cultivation
  • alternate wetting and drying
  • AWD
  • irrigation
  • water-saving technology
  • field water tube
  • agriculture
  • sustainable farming
  • community adoption