A comparative study of urea hydrolysis rate and ammonia volatilization from urea and urea calcium nitrate

1987 ◽  
Vol 11 (1) ◽  
pp. 9-24 ◽  
Author(s):  
AB Eriksen ◽  
M Kjeldby
Keyword(s):  
Comparative Study ◽  
Ammonia Volatilization ◽  
Calcium Nitrate ◽  
Urea Hydrolysis ◽  
Hydrolysis Rate

scholarly journals Using Soil Water to Control Ammonia Emission from Acid Soils with and Without Chicken Litter Biochar

2019 ◽  
Vol 8 (3) ◽  
pp. 23
Author(s):  
Maru Ali ◽  
Ahmed Osumanu Haruna ◽  
Nik Muhamad Abd Majid ◽  
Walter Charles Primus ◽  
Nathaniel Maikol ◽  
...  
Keyword(s):  
Soil Water ◽  
Ammonia Volatilization ◽  
Chemical Properties ◽  
Field Capacity ◽  
Urea Hydrolysis ◽  
Water Levels ◽  
Soil Chemical Properties ◽  
Ammonia Emission ◽  
Ammonia Loss ◽  
Chicken Litter

Although urea use in agriculture is on the increase, increase in pH at soil microsite due to urea hydrolysis which causes ammonia emission can reduce N use efficiency. Among the interventions used to mitigate ammonia loss include urease inhibitors, clinoptilolite zeolite, coated urea, and biochar but with little attention to the use of soil water levels to control ammonia volatilization. The objective of this study was to determine the effects of soil water levels on ammonia volatilization from soils with and without chicken litter biochar. Dry soils with and without chicken litter biochar were subjected to 0%, 25% 50%, 75%, 100%, and 125% soil water. There was no urea hydrolysis in the soil without water. Chicken litter biochar as soil amendment effectively mitigated ammonia loss at 1% to 32% and 80% to 115% field capacity. However, urea used on soil only showed lower ammonia loss at 33% to 79% and 116% to 125% field capacity compared with the soils with chicken litter biochar. At 50% field capacity ammonia loss was high in soils with and without chicken litter biochar. Although chicken litter biochar is reputed for improving soil chemical properties, water levels in this present study affected soil chemical properties differently. Fifty percent field capacity, significantly reduced soil chemical properties. These findings suggest that timely application of urea at the right field capacity can mitigate ammonia emission. Therefore, whether soils are amended with or without chicken litter biochar, urea application should be avoided at 50% field capacity especially in irrigated crops.

Pertes d'azote par volatilisation ammoniacale après fertilisation en forêt de pin gris

1971 ◽  
Vol 1 (2) ◽  
pp. 69-79 ◽  
Author(s):  
D. Carrier ◽  
B. Bernier
Keyword(s):  
Ammonium Nitrate ◽  
Ammonia Volatilization ◽  
Urea Hydrolysis ◽  
Soil Horizons ◽  
The Third ◽  
Joint Application ◽  
Humus Layer ◽  
Coated Urea ◽  
Increasing Precipitation ◽  
Underlying Soil

In a field study, percentage of nitrogen lost as ammonia from a jack pine (Pinusbanksiana Lamb.) soil increased with increasing rates of urea application between 112 and 448 kg N/ha. After 7 days, losses amounted to 18–28% of a 224 kg urea-N/ha application, representing 60–87% of the total losses measured over a 6-week period. Maximum volatilization rates occurred between the third and the fifth day after fertilization, at which time urea hydrolysis was virtually complete. Negligible ammonia losses were measured in plots treated with ammonium sulfate, ammonium nitrate, and sulfur-coated urea. Applying superphosphate with urea markedly depressed ammonia volatilization, an effect which was enhanced by a joint application of K2SO4•MgSO4. Reduction of volatilization by artificial precipitation was significant and increased with increasing precipitation when the latter was applied soon after fertilization; decreases in volatilization were then related to the amount of residual urea subject to diffusion into the humus layer or to leaching towards the underlying soil horizons.

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.

Effects of urea rates, farmyard manure, CaCO3, salinity and alkalinity levels on urea hydrolysis and nitrification in soils

Soil Research ◽  
1988 ◽  
Vol 26 (2) ◽  
pp. 367 ◽  
Author(s):  
V Kumar ◽  
DS Yadav ◽  
M Singh
Keyword(s):  
Constant Temperature ◽  
Farmyard Manure ◽  
Urea Hydrolysis ◽  
Urea Concentration ◽  
Hydrolysis Rate ◽  
Nitrification Rate ◽  
Indian Soils

The effects of urea concentration, farmyard manure, CaCo3, pH and EC levels on urea and nitrification rates in different Indian soils at constant temperature (25 � 1�C) and moisture (50% WHC) were studied. The hydrolysis rate of urea was not proportional to the amount of urea added. In all cases, hydrolysis was completed within 6 days, except with 16.64 dS m-1 EC and 4% and 8% CaCO3 treatments. An increase in CaCO3, pH and EC levels inhibited urea hydrolysis. The NH4+ concentration increased up to 6 days and then decreased up to 24 days, with a corresponding increase in the NO3- concentration. The maximum NO2- concentration was observed at 12 and 18 days and decreased at 24 days. However, accumulation of NO2- continued up to 24 days at higher CaCO3, EC and pH levels. An increase in urea levels decreased the rate of nitrification. The nitrification rate was fast in the presence of farmyard manure and slow at the higher CaCO3, pH and EC levels.

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.

Effect of N‐(n‐butyl)thiophosphoric triamide added to peat and leather in urea‐based fertilizers on urea hydrolysis and ammonia volatilization

2000 ◽  
Vol 31 (19-20) ◽  
pp. 3177-3191 ◽  
Author(s):  
Paola Gioacchini ◽  
Camilla Giovannini ◽  
Claudio Marzadori ◽  
Livia Vittori Antisari ◽  
Andrea Simoni ◽  
...  
Keyword(s):  
Ammonia Volatilization ◽  
Urea Hydrolysis
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