The effect of rate and time of application of Azolla on rice(Oryza Sativa L.)Grain yield

This study was designed to determine the effectiveness of using
azolla in rice fields and to investigate the appropiate time and
quantities of azolla to be incorporated. The trial was conducted
at the University of Zambia Field Station as a pot experiment.
Three different quantities of azolla pinnata at 4, 8 and 12 t/ha
were used to check yield performance compared to urea at 60
kgN/ha and a control (no azolla, no urea). Four times of
application i.e during transplanting (DT), DT and 42 days after
transplanting (DAT); DT and 56 DAT; DT and 70 DAT were studied.
The experiment was arranged as a randomized complete block design
with three replications. There was a slight increase in rice
yield with increasing quantities of azolla. The highest rice
yield with azolla was obtained when azolla was applied at the
rate of 12 t/ha (209 gm/pot), but this did not differ
significantly from that obtained with azolla applied at the rate
of 8 t/ha (203.52 gm/pot). Yield obtained with urea (60 kgN/ha)
(217.11 gm/pot) was the highest. The lowest yield was from the
control plants (130.44 gm/pot). The best treatment combination
was when azolla at a rate of 12 t/ha was applied at the time of
transplanting and 56 days after transplanting. This gave a yield
of 261.27 gm/pot,as compared to a yield of 128.4 gm/pot under the
control treatment. Other parameter studied were plant
height,paicle length,tiller per plant,1000 grain weight,days to
50% flowering,days to maturity and harvest index. From the study
it shows that the use of azolla increases rice yield but not
beyond that obtained with inorganic fertilizers also azolla can
substitute inorganic fertilizer in rice cultivation