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.