Bk. Mandal et al., RELATIVE EFFICIENCY OF AZOLLA AND OTHER ORGANIC MANURES IN WINTER RICE (ORYZA-SATIVA), Indian Journal of Agricultural Sciences, 63(6), 1993, pp. 340-344
An experiment was carried out during July-November 1985 and 1986 at Ka
lyani, to study the effect of Azolla, blue-green algae and other organ
ic manures on 'Jaya' rice (Oryza sativa L.). Grain and straw yields of
rice increased significantly due to incorporation of Azolla, Ipomoea
carnea Jacq., farmyard manure, water lettuce (Pistia stratiotes L.) an
d water hyacinth [Eichhornia crassipes (C. Martius) Solms-Laub.] compa
red with the control. Inoculation with blue-green algae was not benefi
cial, but the effect of dual cropping with Azolla was pronounced with
30% more yield than the control. Basal dressing of Azolla was also sup
erior to top-dressing and dual cropping. The highest grain yield (6.5
tonnes/ha) was recorded with the application of 15 tonnes/ha Azolla 15 kg N/ha at panicle-initiation stage. The extent of yield increase,
compared with the control, due to different treatments, varied from 5
to 107.5%. The treatment with Ipomoea sp proved equal or more efficien
t than Azolla. The N status of soil after harvest of crop depended on
the uptake of N by the plants as well as contribution of Azolla and ot
her manures.