|By goGreen | October 30, 2011|
Azospirilla are a genus of bacteria which live and can colonize the roots of forage and grain grasses and exert beneficial effects on their growth. This grass-bacteria symbiosis differs from the legume-rhizobium symbiosis in that the former does not have root nodulation as a manifestation of the association. These organisms reside mainly at the zone of root elongation, bases of root hairs and root interior.
Some work has been done in rice particularly in India and now in the Philippines. One recent test in India yielded 6.5 T/ha with Azospirilla vs. 4.4 T/ha without it. In experiments in Cavite and Negros provinces, the use of Azospirilla in combination with 40 kg N increased rice yields by 24% and 55%, respectively, while Cavite experiments using only Azospirilla increased rice yields by 18%.
The exact cause for the yield increases is not yet clear. However, it is known that a higher percentage increase in yield occurs under conditions where lower amounts of fertilizer N is used.
Aside from the nitrogen fixation, several benefits can be derived from azospirillum inoculation: it promotes root hair development and branching — increasing the uptake of NPK and microelements; improves water status of plants; and increases dry matter accumulation and grain yield. Inoculating plants with azospirillum can reduce the required nitrogen fertilizer from 1/3 up to 213.
HOW TO INOCULATE RICE SEEDLINGS:
1. Mix the inoculant with water. About 750-1000 9 inoculant is required to treat seedlings needed to plant 1 hectare.
2. Put the mixed inoculant in a container for dipping the seedlings. If a big container is not available, prepare a bunded piece of land and line this with plastic
3. Soak the seedlings into the mixture for at least 3 hours. If possible, inoculate/soak the seedlings overnight before transplanting.
Mix the inoculant with water
Put the mixed inoculant in a container
SOURCE: Low-external Input Rice Production (IIRR, 292 p.)