ORIGINAL PAPER Fluxes of methane and nitrous oxide in water-saving rice production in north China Christine Kreye Æ Klaus Dittert Æ Xunhua Zheng Æ Xu Zhang Æ Shan Lin Æ Hongbin Tao Æ Burkhard Sattelmacher Received: 10 May 2006 / Accepted: 12 November 2006 / Published online: 13 January 2007 Ó Springer Science+Business Media B.V. 2006 Abstract Lowland rice production is currently facing serious water shortages in numerous Asian countries. In the North China Plain water limitations are severe. Water-saving rice produc- tion techniques are therefore increasingly searched for. Here we present the first study of trace gas emissions from a water-saving rice production system where soils are mulched and are kept close to field capacity in order to compare their contribution to global warming with traditional paddy rice. In a two-year field experiment close to Beijing, CH 4 and N 2 O fluxes were monitored in two forms of the Ground Cover Rice Production System (GCRPS) and in traditional paddy fields using closed chambers. With paddy rice the observed CH 4 emissions were very low, about 0.3 g CH 4 m –2 a –1 in 2001 and about 1 g CH 4 m –2 a –1 in 2002. In GCRPS, the CH 4 emissions were negligible. N 2 O fluxes in GCRPS were similar, 0.5 to 0.6 g N 2 Om –2 a –1 in 2001 and 2002, and emission peaks mainly followed fertilizer applications. In paddy rice, N 2 O fluxes were unexpectedly low throughout the year 2001 (0.03 g N 2 Om –2 a –1 ), and in 2002 larger emissions occurred during the drainage period. So with 0.4 g N 2 Om –2 a –1 the cumulative flux was similar to emissions in GCRPS. Total CO 2 equivalent fluxes calculated according to IPCC methodology were tenfold higher in GCRPS compared to paddy in 2001. In 2002, fluxes from both systems were similar with 175 and 141 g CO 2 equivalents m –2 a –1 from GCRPS and paddy. Keywords CH 4 Á Greenhouse gas emissions Á N 2 O Á Plastic film mulching Á Water-saving rice Introduction In China, rice accounts for 44% of total grain production (Li 2001) and in 2001, 93% of the 28.6 million ha of rice production area in China was cultivated under irrigated lowland conditions (IRRI 2003). Partly due to intensified competition between agricultural and industrial water needs and also because of rapid urbanization, irrigation water is becoming increasingly scarce (Li 2001; Burkhard Sattelmacher deceased. C. Kreye Á K. Dittert (&) Á H. Tao Á B. Sattelmacher Institute of Plant Nutrition and Soil Science, Kiel University, Kiel, Germany e-mail: kdittert@plantnutrition.uni-kiel.de C. Kreye Á X. Zhang Á S. Lin Á H. Tao Department of Plant Nutrition, China Agricultural University, Beijing, China X. Zheng State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry, Institute of Atmospheric Physics, Chinese Academy of Science, Beijing, China 123 Nutr Cycl Agroecosyst (2007) 77:293–304 DOI 10.1007/s10705-006-9068-0