The effect of phenyl phosphorodiamidate on urease activity and ammonia volatilization in flooded rice

1987 ◽  
Vol 3 (3) ◽  
pp. 183-188 ◽  
Author(s):  
F. Pedrazzini ◽  
R. Tarsitano ◽  
P. Nannipieri
Keyword(s):  
Urease Activity ◽  
Ammonia Volatilization ◽  
Flooded Rice ◽  
Phenyl Phosphorodiamidate

Ammonia volatilization from flooded rice soil using CAS and OSC methods

2021 ◽  
Vol 20 (2) ◽  
pp. 202-207
Author(s):  
S. Vanitha ◽  
V. Ravikumar ◽  
T. Sherene Jenita Rajammal
Keyword(s):  
Ammonia Volatilization ◽  
Rice Soil ◽  
Flooded Rice ◽  
Flooded Rice Soil

Problems in the use of microplots for assessing the fate of urea applied to flooded rice

1988 ◽  
Vol 39 (3) ◽  
pp. 351 ◽  
Author(s):  
ACF Trevitt ◽  
JR Freney ◽  
JR Simpson ◽  
WA Muirhead
Keyword(s):  
Solar Radiation ◽  
Preliminary Analysis ◽  
Ammonia Volatilization ◽  
Urea Hydrolysis ◽  
Incident Solar Radiation ◽  
Size And Shape ◽  
Flooded Rice ◽  
Ph Values ◽  
Plot Size ◽  
Heat Penetration

The effects of differences in size of microplot and type of enclosure on the floodwater parameters determining ammonia volatilization were studied. The results show that the use of enclosures can retard urea hydrolysis, suppress the maximum daytime pH values (an effect which is cumulative over a number of days), and significantly reduce the potential for ammonia volatilization. These effects are the consequence of lowered light (and heat) penetration in the enclosed area due to shading of the floodwater by the enclosure walls. The magnitude of these effects varies with plot size and shape, and the material used for construction of the plot wall. A preliminary analysis suggests that, if errors due to shading are acceptable when 90% or more of the incident solar radiation always penetrates to the enclosed floodwater, then square plots with opaque walls must be at least 1.2 m along a side and cylindrical plots must be at least 1.2 m in diameter when wall height is 0.1 m above the floodwater.

Use of surface films to reduce ammonia volatilization from flooded rice fields

1988 ◽  
Vol 39 (2) ◽  
pp. 177 ◽  
Author(s):  
GX Cai ◽  
JR Freney ◽  
E Humphreys ◽  
OT Denmead ◽  
M Samson ◽  
...  
Keyword(s):  
Ammonia Volatilization ◽  
Nitrogen Loss ◽  
Surface Film ◽  
Cetyl Alcohol ◽  
Ammonia Emission ◽  
Surface Films ◽  
Flooded Rice ◽  
Strong Winds ◽  
Long Chain Alcohol ◽  
Long Chain

This paper presents the results of experiments on the control of ammonia volatilization from flooded rice by the use of surface films of organic compounds.Preliminary experiments in evaporation pans, 1.2 m diameter, buried in an upland field of mown pasture, showed that ammonia volatilization from water could be reduced by applications of surface films of long chain alcohols; the effect increased with increasing length of carbon chain.The most effective way to add the film was to dissolve the long chain alcohol in ethanol, and to distribute the solution on the surface of the water.In an experiment in a flooded rice field, additions of cetyl alcohol dissolved in ethanol significantly reduced the rate of ammonia emission and total nitrogen loss. The effect was short-lived, probably due to microbiological decomposition of the cetyl alcohol and dispersion of the surface film by strong winds.

The role of Azolla in curbing ammonia volatilization from flooded rice systems

1995 ◽  
pp. 165-174
Author(s):  
Paul L. G. Vlek ◽  
Moussa Y. Diakite ◽  
Henning Mueller
Keyword(s):  
Ammonia Volatilization ◽  
Flooded Rice

Effect of source and rate of nitrogen on grain yield of rice and wheat

1984 ◽  
Vol 103 (3) ◽  
pp. 691-693
Author(s):  
H. S. Thind ◽  
Bhajan Singh ◽  
M. S. Gill
Keyword(s):  
Ammonium Nitrate ◽  
Ammonium Sulphate ◽  
Ammonia Volatilization ◽  
Calcium Nitrate ◽  
Calcareous Soils ◽  
Rice Grain ◽  
Flooded Rice ◽  
Nitrate N ◽  
Yield Responses ◽  
Different Sources

It is well known that the uptake of fertilizer-N by crops is relatively inefficient, often amounting to less than half the quantity applied. Some becomes unavailable by combining with soil organic matter and some is lost from the system by surface runoff, leaching, denitriiication or ammonia volatilization. Most research has shown urea to be less effective than other sources of N when applied under conditions where ammonia volatilization becomes significant, especially when broadcast on the surface of alkaline and calcareous soils. Devine & Holmes (1964) found that ammonium sulphate was less effective than ammonium nitrate for wheat on a calcareous soil. Nitrogen recovery by wheat and barley tended to be similar for various N-fertilizers but further recovery in the following year was highest from calcium nitrate followed by ammonium sulphate and ammonium nitrate (Alessi & Power, 1973). On the other hand the efficiency of nitrate-N for flooded rice is less than that of ammoniacal fertilizers, owing to denitrification and leaching. Sarkar et al. (1978) found that rice grain yields with ammonium sulphate were significantly higher than with urea whereas Narain & Datta (1974) reported that urea and ammonium sulphate were equivalent and gave significantly higher yields of rice than ammonium nitrate. Therefore, yield responses to different sources of N vary depending upon soil, crop, climate and management factors; the study reported here was initiated to provide information on the relative performance of various N carriers applied to wheat and rice in the Punjab.

Ammonia Volatilization Losses from Flooded Rice Soils

1978 ◽  
Vol 42 (5) ◽  
pp. NP-NP ◽  
Author(s):  
D. S. Mikkelsen ◽  
S. K. De Datta ◽  
W. N. Obcemea
Keyword(s):  
Ammonia Volatilization ◽  
Rice Soils ◽  
Flooded Rice
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