Water regime-nitrogen fertilizer incorporation interaction: Field study on methane and nitrous oxide emissions from a rice agroecosystem in Harbin, China
Wenjun Dong , Jia Guo , Lijun Xu , Zhifeng Song , Jun Zhang , Ao Tang , Xijuan Zhang , Chunxu Leng , Youhong Liu , Lianmin Wang , Lizhi Wang , Yang Yu , Zhongliang Yang , Yilei Yu , Ying Meng , Yongcai Lai
DOI:10.1016/j.jes.2017.06.007
Received November 23, 2016,Revised April 16, 2017, Accepted June 09, 2017, Available online June 23, 2017
Volume 30,2018,Pages 289-297
Water regime and nitrogen (N) fertilizer are two important factors impacting greenhouse gases (GHG) emission from paddy field, whereas their effects have not been well studied in cold region. In this study, we conducted a two-year field experiment to study the impacts of water regime and N fertilizer on rice yields and GHG emissions in Harbin, China, a cold region located in high latitudes. Our results showed that intermittent irrigation significantly decreased methane (CH4) emission compared with continuous flooding, however, the decrement was far lower than the global average level. The N2O emissions were very small when flooded but peaked at the beginning of the disappearance of floodwater. The N fertilizer treatments increased CH4 emissions at low level (75kgN/ha). But both CH4 and N2O emissions were uninfluenced at the levels of 150kgN/ha and 225kgN/ha. Rice yields increased under intermittent irrigation and were highest at the level of 150kgN/ha. From our results, we recommended that the intermittent irrigation and 150kgN/ha as the ideal water regime-nitrogen fertilizer incorporation for this area to achieve low GHG emissions without impacting rice yields.
