Water-saving practices for rice production has become one of the major agricultural policies in China due
to the severe water scarcity. However, greenhouse gases emissions from paddy field may be changed
with water-saving practices. In the two-year field experiment at Thaihu Lake Basin of China, CH4 and
N2O fluxes from paddy field under controlled irrigation and continuous flooding irrigation were monitored
using closed chambers. Total CH4 emission from paddy field under controlled irrigation during
the rice-growing period were 2.47 and 1.88 g m2 in 2006 and 2007, respectively, reduced by 79.1% on
average compared with continuous flooding irrigation. The CH4 emission from paddy field was further
concentrated in the initial and middle tillering stages of rice growth under controlled irrigation for
2 years. The N2O emission from paddy field under controlled irrigation was mostly larger than those from
flooding irrigation during the rice-growing period. Total N2O emission from paddy field under controlled
irrigation during the rice-growing period was 106 mg m2, increased by 10.6% compared with those from
flooding irrigation. Carbon dioxide equivalents of CH4 and N2O emissions from paddy field during the
rice-growing period under controlled irrigation were 788 kg CO2 ha1, reduced by 61.4% compared with
those from flooding irrigation. It can be concluded that controlled irrigation is an effective technique for
mitigating the carbon dioxide equivalents of CH4 and N2O emissions from paddy field.
Water-saving practices for rice production has become one of the major agricultural policies in China dueto the severe water scarcity. However, greenhouse gases emissions from paddy field may be changedwith water-saving practices. In the two-year field experiment at Thaihu Lake Basin of China, CH4 andN2O fluxes from paddy field under controlled irrigation and continuous flooding irrigation were monitoredusing closed chambers. Total CH4 emission from paddy field under controlled irrigation duringthe rice-growing period were 2.47 and 1.88 g m2 in 2006 and 2007, respectively, reduced by 79.1% onaverage compared with continuous flooding irrigation. The CH4 emission from paddy field was furtherconcentrated in the initial and middle tillering stages of rice growth under controlled irrigation for2 years. The N2O emission from paddy field under controlled irrigation was mostly larger than those fromflooding irrigation during the rice-growing period. Total N2O emission from paddy field under controlledirrigation during the rice-growing period was 106 mg m2, increased by 10.6% compared with those fromflooding irrigation. Carbon dioxide equivalents of CH4 and N2O emissions from paddy field during therice-growing period under controlled irrigation were 788 kg CO2 ha1, reduced by 61.4% compared withthose from flooding irrigation. It can be concluded that controlled irrigation is an effective technique formitigating the carbon dioxide equivalents of CH4 and N2O emissions from paddy field.
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