ISSN:
1432-0789
Keywords:
N2O release
;
Cropping systems
;
Waste water treatment
;
Activated sludge
;
Nitrification
;
Demitrification
;
Carbon availability
;
Available carbon-to-nitrate ratio
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Geosciences
,
Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
Notes:
Abstract Nitrous oxide emissions, nitrate, water-soluble carbon and biological O2 demand (BOD5) were quantified in different cropping systems fertilized with varying amounts of nitrogen (clayey loam, October 1991 to May 1992), in an aerated tank (March 1993 to March 1994), and in the nitrification-denitrification unit (March to July 1994) of a municipal waste water treatment plant. In addition, the N2O present in the soil body at different depths was determined (February to July 1994). N2O was emitted by all cropping systems (mean releases 0.13–0.35 mg N2O m-2 h-1), and all the units of the domestic waste water treatment plant (aerated tank 0–6.2 mg N2O m-2 h-1, nitrification tank 0–204,3 mg N2O m-2, h-1, denitrifying unit 0–2.2 mg N2O m-2 h-1). During the N2O-sampling periods estimated amounts of 0.9, 1.5, 2.4 and 1.4 kg N2O−N ha-1, respectively, were released by the cropping systems. The aerated, nitrifying and denitrifying tanks of the municipal waste water treatment plant released mean amounts of 9.1, 71.6 and 1.8 g N2O−N m-2, respectively, during the sampling periods. The N2O emission were significantly positively correlated with nitrate concentrations in the field plots which received no N fertilizer and with the nitrogen content of the aerated sludge tank that received almost exclusively N in the form of NH 4 + . Available carbon, in contrast, was significantly negatively correlated with the N2O emitted in the soil fertilized with 80 kg N ha-1 year. The significant negative correlation between the emitted N2O and the carbon to nitrate ratio indicates that the lower the carbon to nitrate ratio the higher the amount of N2O released. Increasing N2O emissions seem to occur at electron donorto-acceptor ratios (CH2O or BOD5-to-nitrate ratios) below 50 in the cropping systems and below 1200–1400 in the waste water treatment plant. The trapped N2O in the soil body down to a depth of 90 cm demonstrates that agricultural production systems seem to contain a considerable pool of N2O which may be reduced to N2 on its way to the atmosphere, which may be transported to other environments or which may be released at sometime in the future.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00335953
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