Effect of Different Plant Spacing Pattern on the Growth of Azolla and Rice

Azolla- Anabaena consortium grew well in the rice field ecosystem and fixed significantly more nitrogen in double-narrow-row spacing (15 x 7cm, 15 x 40 cm) than in normal spacing (15 x20 cm) in the late inoculation treatments (30 DAP). But no significant difference in the growth and nitrogen fixation of Azolla could be marked between the said spacing patterns, when the fern was inoculated early (5 DAP). However, early inoculation controlled the weed growth in the rice field more efficiently than the late ones. It recorded significantly higher grain and straw yield in rice than its inoculation in later stage irrespective of spacing pattern. Increase in organic carbon and total N of the soil was also recorded due to Azolla inoculation.