Field measurement and modelling of nitrous oxide and dinitrogen emission from paddy soil | |
| Author | Kharbuja, Ram Gopal |
| Call Number | AIT Thesis no.WM-01-08 |
| Subject(s) | Nitrous oxide--Thailand--Measurement Nitrogen--Thailand--Measurement Soils--Nitrogen content--Thailand--Measurement |
| Note | A thesis report submitted in Partial fulfillment of the requirements for the degree of Master of Engineering |
| Publisher | Asian Institute of Technology |
| Abstract | A study for assessment of N20+N2 emission from paddy soil was carried out by the acetylene inhibition technique in acidic-sulphate clayey soil of Bangkok, Thailand. The objective was to assess potential denitrification loss of nitrogen fertilizer in N20 and N2 form under conventional rice cultivation practice. Field measurements of nitrous oxide emissions from both acetylene treated and controlled sites were carried out for one cropping season, October to January, by close chamber technique with 0.3 x 0.3 m2 base area enclosing three plants with eleven stems. Nitrous oxide flux from acetylene treated and controlled sites were found dependent on soil temperature and nitrate concentration in plow layer, where highly reductive state was prominent during the ponded period. DNDC model satisfactorily reproduced N20+N2 and N20 flux rate close to the observed flux from paddy soil with small relative errors. The total potential loss in N20+N2 form was estimated to be 3.938 kg-N/ha/season at N.T.P. equivalent to 4.5% of total applied fertilizer in the field. About 95.4% of the total loss were found in N20 form, which is the second highest potential green house gas after the chloflorocarbon. Thin layer of ponding water in the surface was found sufficient to suppress extremely high flux ofN20 due to dissolution in water. Simulation for alternate wet and dry condition in paddy field showed high loss of nitrogen in N20. Further experimental studies including microbial observations with different water and fertilizer applications at different locations in different cropping seasons and soils were recommended to evaluate the model performance in a wide range. |
| Year | 2002 |
| Type | Thesis |
| School | School of Engineering and Technology (SET) |
| Department | Department of Civil and Infrastucture Engineering (DCIE) |
| Academic Program/FoS | Water Engineering and Management (WM) |
| Chairperson(s) | Iida, Toshiaki ; |
| Examination Committee(s) | Tawatchai Tingsanchali ;Clemente, Roberto S. ;Babel, Mukand S. ; |
| Scholarship Donor(s) | Danish International Development Agency (DANIDA-AIT Co-operation); |
| Degree | Thesis (M.Eng.) - Asian Institute of Technology, 2002 |