ISSN:
1573-5036
Keywords:
Cyanobacteria
;
`in situ' N2 fixation
;
N fertilizer
;
15N balance
;
rice
Source:
Springer Online Journal Archives 1860-2000
Topics:
Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
Notes:
Abstract This study investigate the potential contribution of nitrogen fixation by indigenous cyanobacteria to rice production in the rice fields of Valencia (Spain). N2-fixing cyanobacteria abundance and N2 fixation decreased with increasing amounts of fertilizers. Grain yield increased with increasing amounts of fertilizers up to 70 kg N ha-1. No further increase was observed with 140 kg N ha-1. Soil N was the main source of N for rice, only 8–14% of the total N incorporated by plants derived from 15N fertilizer. Recovery of applied 15N-ammonium sulphate by the soil–plant system was lower than 50%. Losses were attributed to ammonia volatilization, since only 0.3–1% of applied N was lost by denitrification. Recovery of 15N from labeled cyanobacteria by the soil–plant system was higher than that from chemical fertilizers. Cyanobacterial N was available to rice plant even at the tillering stage, 20 days after N application.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1023/A:1004737422842
