Monday, March 8, 2010

Biological nitrogen fixation in corn

Corn (Zea mays L.) can establish rhizospheric or endophytic associations with various nitrogen-fixing bacteria (diazotrophs) such as Azospirillum, Klebsiella, Pantoea, Herbaspirillum, Bacillus, Rhizobium etli and Burkholderia. Most of these diazotrophs can grow in the intercellular tissue of plants without causing any disease.

Biological nitrogen fixation (BNF) is the biological process by which nitrogen (N2) in the atmosphere is converted to ammonia by an enzyme called nitrogenase. The screening of plant genotypes for their enhanced ability to acquire nitrogen by BNF can reduce the use of expensive nitrogen fertilizers in several important crops like sugarcane, rice, wheat and corn. It can greatly benefit particularly the poor farmers of developing countries.

In a recent study aimed to quantify the symbiotic biological nitrogen fixing activity of a range of commercial corn cultivars, Montanez et al. (2009) demonstrated that corn cultivars obtain significant nitrogen from BNF, the level of which varied with corn cultivar and nitrogen fertilization level. The study showed that some cultivars were more sensitive than others to nitrogen application and that 15N isotope dilution method is a useful tool to screen and select corn cultivars with any potential BNF.


Montanez A, Abreu C, Gill PR, Hardarson G, and Sicardi M. 2009. Biological nitrogen fixation in maize (Zea mays L.) by 15N isotope dilution and identification of associated culturable diazotrophs. Biology and Fertility of Soils 45: 253-263


Anonymous said...

This is interesting blog. Keep it up!

Anonymous said...

Dr. Asio, I am interested in organic corn production in the Philippines. Do you have information on it? Thank you-J. Cabantog

Victor B. Asio said...

Thanks. I know of a few persons who are doing organic crop production in the country.Please send me your email address so that I can send you more information on the subject.