Nitrous Oxide Emissions from Vegetable Cropping Systems
Author(s)
Primary Supervisor
Ghadiri, Hossein
Chen, Chengrong
Other Supervisors
Wang, Weijin
Moody, Philip
Year published
2015
Metadata
Show full item recordAbstract
Agricultural manipulation of the soil nitrogen (N) cycle has caused a significant increase in nitrous oxide (N2O) emissions during the past five decades. Nitrous oxide is one of the major greenhouse gases with potent and long-lasting global warming effects [298 times higher than carbon dioxide (CO2) over a time period of 100 years]. The major biogenic processes responsible for N2O production in agricultural soils are identified as nitrification which is the oxidation of ammonium (NH4+) to nitrite (NO2-) and nitrate (NO3-) and denitrification that is the anaerobic reduction of NO2- and NO3- to gaseous nitric oxide (NO), N2O ...
View more >Agricultural manipulation of the soil nitrogen (N) cycle has caused a significant increase in nitrous oxide (N2O) emissions during the past five decades. Nitrous oxide is one of the major greenhouse gases with potent and long-lasting global warming effects [298 times higher than carbon dioxide (CO2) over a time period of 100 years]. The major biogenic processes responsible for N2O production in agricultural soils are identified as nitrification which is the oxidation of ammonium (NH4+) to nitrite (NO2-) and nitrate (NO3-) and denitrification that is the anaerobic reduction of NO2- and NO3- to gaseous nitric oxide (NO), N2O or N2. Although the current concentration of N2O in the atmosphere is relatively lower than other greenhouse gases, it is annually increasing at a rate of 0.25%. Vegetable cropping systems, a major agricultural activity worldwide, generally comprise intensive cultivation and high rates of N application. However, the N recovery from intensively cultivated vegetable fields is reported to be only 20 - 50% of the applied N fertiliser, suggesting large amounts of N loss from these fields. In Australia, horticulture represents less than 1% of land used for agriculture, but accounts for 6-12% of N fertiliser use in agriculture and its contribution to national N2O emissions is significant.
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View more >Agricultural manipulation of the soil nitrogen (N) cycle has caused a significant increase in nitrous oxide (N2O) emissions during the past five decades. Nitrous oxide is one of the major greenhouse gases with potent and long-lasting global warming effects [298 times higher than carbon dioxide (CO2) over a time period of 100 years]. The major biogenic processes responsible for N2O production in agricultural soils are identified as nitrification which is the oxidation of ammonium (NH4+) to nitrite (NO2-) and nitrate (NO3-) and denitrification that is the anaerobic reduction of NO2- and NO3- to gaseous nitric oxide (NO), N2O or N2. Although the current concentration of N2O in the atmosphere is relatively lower than other greenhouse gases, it is annually increasing at a rate of 0.25%. Vegetable cropping systems, a major agricultural activity worldwide, generally comprise intensive cultivation and high rates of N application. However, the N recovery from intensively cultivated vegetable fields is reported to be only 20 - 50% of the applied N fertiliser, suggesting large amounts of N loss from these fields. In Australia, horticulture represents less than 1% of land used for agriculture, but accounts for 6-12% of N fertiliser use in agriculture and its contribution to national N2O emissions is significant.
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Thesis Type
Thesis (PhD Doctorate)
Degree Program
Doctor of Philosophy (PhD)
School
Griffith School of Environment
Copyright Statement
The author owns the copyright in this thesis, unless stated otherwise.
Item Access Status
Public
Subject
N2O emissions
Nitrous oxide
Agricultural soils
Vegetable cropping systems