Journal of Food, Agriculture and Environment

Diurnal patterns of methane and nitrous oxide emissions form rice paddy under different soil moisture conditions

Author(s):

Junzeng Xu ^{1, 2}, Shizhang Peng ^1*, Huijing Hou ², Shihong Yang ², Yupu He ²

Recieved Date: 2012-07-12, Accepted Date: 2012-10-06

Abstract:

Paddy fields are one of the major anthropogenic sources of methane (CH₄) and nitrous oxide (N₂O) emissions. Soil moisture condition has been recognized as one of the most important factors that affect CH₄ and N₂O emission from paddy fields. Water-saving irrigation techniques for rice cultivation which have been widely used in China, lead to huge change in soil moisture conditions and soil biochemical processes, and that is expected to strongly alter trace gases emissions. Field experiments were carried out at Kunshan Experiment Station (31°15´15´´N, 120°57´43´´E) in East China, to investigate the effect of varied soil moisture conditions on diurnal variations of CH₄ and N₂O emissions from non-flooding controlled irrigation (CI) rice paddy. In traditional flooding irrigation (TI) paddy, CH₄ emissions are likely got peaks in noon, and N₂O emissions likely followed a similar diurnal pattern. With decrease of soil moisture in CI paddy, CH₄ fluxes reduced and N₂O fluxes increased. Optimal soil moisture condition for high nitrous oxide emission from CI paddy is about of 73.1% water filled pore space (WFPS). In TI paddy, the first drainage followed long-term flooding leads to even greater N₂O emissions than those from CI paddy, although soil moisture in TI paddy are much higher than optimal soil moisture. Fluxes on 10:00 are always near daily average fluxes for CH₄ and less than daily average fluxes for N₂O emissions from TI paddy, but when it comes to CI paddy, fluxes on 10:00 h are always larger than daily average fluxes for both CH₄ and N₂O emissions. We concluded that non-flooding conditions in rice paddy result in both great change in emission fluxes of CH₄ and N₂O, and change in their diurnal patterns. Fluxes measured around 10:00 in CI paddy likely overestimate daily average emission fluxes of both CH₄ and N₂O.

Keywords:

Methane, nitrous oxide, rice paddy, soil moisture, diurnal variation, soil redox potential, non-flooding controlled irrigation, flooding irrigation

---

Journal: Journal of Food, Agriculture and Environment
Year: 2012
Volume: 10
Issue: 3&4
Category: Environment
Pages: 1265-1270

---

Full text for Subscribers

---

Information:

Note to users

The requested document is freely available only to subscribers/registered users with an online subscription to the Journal of Food, Agriculture & Environment. If you have set up a personal subscription to this title please enter your user name and password. All abstracts are available for free.

Article purchasing

If you like to purchase this specific document such as article, review or this journal issue, contact us. Specify the title of the article or review, issue, number, volume and date of the publication. Software and compilation, Science & Technology, all rights reserved. Your use of this website details or service is governed by terms of use. Authors are invited to check from time to time news or information.

---

Purchase this Article:   20 Purchase PDF Order Reprints for 15

---

Share this article :