Doing away fertilisers

researchers in Germany have discovered a group of hitherto unknown nitrogen-fixing bacteria deep inside the roots of Kallar grass, Leptochloa fusca in Pakistan. This grass grows wild in salty soil and can be grown without fertiliser. Thomas Hurek and Reinhard Hurek of the Max Planck Institute for Terrestrial Microbiology in Marburg, Germany, say that the microorganisms belong to a new genus, which they have named Azoarcus .

For twenty years, researchers have been struggling to find varieties of rice that can take nitrogen from the air and 'fix' it like legumes, reducing the need for fertilisers.
The researchers carried out laboratory experiments showing that Azoarcus can colonise rice plants and produce a nitrogen-fixing enzyme while it is outside the plants' roots. Rice plants inoculated with the bacteria in the lab appear to grow about 10 to 20 per cent better than plants without the bacteria, but the researchers point out that more tests will be needed to prove that this is a result of the nitrogen-fixing activity. They feel that these experiments offer the best hope for reducing the use of fertilisers