ISSN:
1573-5036
Keywords:
Azolla pinnata
;
Nitrogen fixation
;
N yield
;
Oryza sativa
;
Urea-N
Source:
Springer Online Journal Archives 1860-2000
Topics:
Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
Notes:
Abstract Application of 0, 30, 60, 90 and 120 kg N ha−1 of urea (U) in split doses with (and without)Azolla pinnata, R. Brown was studied for three consecutive seasons under planted field condition. Fresh weight (FW), acetylene reduction activity (ARA) and N yield of Azolla were found to be maximum 14 days after inoculation (DAI). Among the different treatments, maximum Azolla growth was recorded in no N control. The FW, ARA and N yield of Azolla were inhibited increasingly with the increase in N levels. Irrespective of season, FW and N yield of Azolla were inhibited only a small extent with 90 kg N ha−1 U, beyond which the inhibition was pronounced. ARA was inhibited only slightly up to 60 kg N ha−1 of U. Grain yield and crop N uptake of rice increased significantly up to 90 kg N ha−1 of U (alone or in combination with Azolla) in the dry seasons (variety IR 36) and up to 60 kg N ha−1 U in the wet season (variety CR 1018).
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF02203082
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