[N2O emission from rice-rapeseed rotation system in Chengdu Plain of Sichun Basin].
By using static chamber/gas chromatograph techniques, the N2O emission from rice-rapeseed rotation system in Chengdu Plain of Sichuan Basin was measured from June 2005 to June 2006, with its characteristics and affecting factors investigated. The results showed that the total emission of N2O in a rotation cycle was (8.3 +/- 2.8) kg x hm(-2) x a(-1), and the emission in rice season, rapeseed season and fallow season accounted for 30%, 65%, and 5% of the total, respectively. In rice season, the mean N2O flux was higher during alternative drainage and irrigation than during continuous flooding and drainage, and was roughly the same during continuous flooding and drainage. N application was the main driving factor for the appearance of N2O emission peak, and the lower moisture content in surface soil layer in rapeseed season and fallow season was the main cause inducing soil N2O absorption. Soil moisture, soil temperature, N application, and crop involvement affected the N2O emission to various extents, and soil moisture was the key factor affecting the N2O emission. To avoid the high frequency of dry and wet alternation in rice season or to regulate soil moisture content to a level of 50%-70% WFPS (percentage of water-filled pore space) in rapeseed season and fallow season could effectively decrease the N2O emission from the rice-rapeseed rotation system.
Yu
Ya-Jun
YJ
Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, Chengdu 610041, China. yuyajun0211@126.com
Zhu
Bo
B
Wang
Xiao-Guo
XG
Xiang
Hong-Yan
HY
Zheng
Xun-Hua
XH
D000383:Agriculture / Q000379:methods; D000393:Air Pollutants / Q000032:analysis*; D029741:Brassica rapa / Q000254:growth & development*; D002681:China; D017753:Ecosystem; D004784:Environmental Monitoring; D009609:Nitrous Oxide / Q000032:analysis*; D012275:Oryza / Q000254:growth & development*; D012621:Seasons; D012987:Soil / Q000032:analysis
D000393:Air Pollutants; D012987:Soil; D009609:Nitrous Oxide