Science - November 6, 2013

Growing rice with less water

Albert Sikkema

Looking for varieties that give high yields on ‘dry’ fields.

You can grow rice with less water. It requires less energy but has a few disadvantages: lower yields per hectare and greater loss of nitro­gen. These findings emerged from field trials in Pakistan conducted by PhD student Masood Awan.

Rice is grown in paddies – inundated fields where you plant the rice out. That is the image of rice farming we tend to have. It is less widely known that there is also aerobic rice, which you can sow on a patch of land and irrigate it afterwards. Growing water shortages are putting conventional rice farming under pressure in many regions and aerobic rice cultivation is on the increase. One problem with it, though, is that aerobic rice is less productive. Water shortages are making Pakistani farmers eager to try out the water-saving varieties but they do not include varieties of  their favourite basmati rice. And the aerobic varieties they can get hold of are far less lucrative for them.

nitrogen disappears

PhD student Masood Awan tested the potential of aerobic rice in the hot Punjab region of Pakistan. He tested three local and two exotic varieties, varying the amounts of irrigation water and nitrogen applied. He found that the exotic varieties delivered particularly good harvests while cutting water consumption by 20 percent. He did discover, however, that extra fertilizer hardly increases the yield, as it does in a paddy. So what happens to all the nitrogen not absorbed by the rice plants? ‘It probably doesn’t stay in the soil,’ says supervisor Pepijn van Oort. ‘I think the nitrogen disappears into the air through a process of nitrification and denitrification.’ The ball is now in the court of the plant breeders. Wanted: a rice variety as tasty as basmati that thrives on a short growing season under dry conditions.

Re:actions 2

  • Cristian valdivieso

    Great research.
    Ive been doing sometido research about a technique of rice producción.
    SRI system of rice intensificación.
    it looks forward the distance between plants, the age you trasplant them (in case of indirect planting). And algo about the usage of water. Some studies talk about that rice plants need a aerobic environment to develop instead of the common anaerobic environment that requieres hundreds of m3

  • Marcia Carvalho

    The same yield gap occurs in Brazilian fields, where aerobic rice is grown on weathered and acid soils of the savannas. Nowadays changes in rainfall pattern and temperature rise has made the production of this staple food challenging, especially among smallholder farmers. Massod has proved that producing rice with less water is possible and this is very promising. More important than increasing yields would be stability of production under aerobic conditions.