Study on CH(4) and N(2)O emissions from water-saving irrigation in Phaeozem paddy fields in cold areas

Increasing greenhouse gas emissions and water shortage are two main problems associated with cultivation of rice. Soil moisture control is not only a core technology in water-saving irrigation, but also a decisive factor of greenhouse gas emissions. The CH(4) and N(2)0 emission fluxes from intermittent irrigation and flooding irrigation in Phaeozem paddy fields in cold area were measured in-situ to provide a theoretical basis for studying the regulation of CH(4) and N(2)O emissions and comprehensive assessing the effect of intermittent irrigation on the environment and control of greenhouse gas emissions. During the rice growing period, CH(4) emissions peaked at the tillering stage, whilst N(2)0 emissions peaked twice at the tillering and milky ripening stages. The accumulated emission of N(2)O from the implementation of flooding irrigation in paddy fields was 6.46 gm(-2), whilst that from intermittent irrigation was 5.47 gm(-2). The accumulated emission of N(2)0 from the implementation of flooding irrigation in paddy fields was 36.88 mgm(-2), whilst that from intermittent irrigation was 68.47 mgm(-2). The global warming potential of CH(4) and N(2)0 was 1362.7lkgCO(2)ha(-1) from intermittent irrigation in paddy fields, a value 108.12 kgCO(2)ha(-1) lower than that from flooding irrigation. Intermittent irrigation can thus be used to effectively decrease and control the combined greenhouse effect of CH4 and N20 emissions from rice paddy fields.