ISSN:
1573-0867
Keywords:
ammonium sulphate
;
fertilizer-N recovery
;
NH3 volatilization
;
rice
;
urea
Source:
Springer Online Journal Archives 1860-2000
Topics:
Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
Notes:
Abstract In a pot experiment it was established that NH4 volatilization losses were larger with urea than with ammonium sulphate used as a basal fertilizer for lowland rice. The difference arose from the pH-increasing effect of urea in the floodwater. This rise in pH promoted the growth of algae which in turn were responsible for large diurnal fluctuations in the pH of the floodwater thus enhancing the loss of NH3 during daytime. Ammonium sulphate lowered the pH of the water which suppressed the growth of algae. Once the rice canopy had closed, the algal population declined and the diurnal pH fluctuations largely disappeared. Urea as a topdressing was found to be less liable to give rise to NH3 volatilization than when added as basal dressing. The highest N recovery was obtained with ammonium sulphate used as basal dressing and urea as topdressing. Working a basal dressing into the soil improves the fertilizer-N recovery of urea-N, but not of ammonium sulphate-N, the latter being already high without soil incorporation.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01074367
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