EFFECTS OF IRRIGATION PATTERNS AND STRAW RETURNING ON CH4 EMISSIONS IN COLD PADDY FIELDS

Aiming at the increasing problem of CI, emissions in China's farmland, this paper takes black soil rice in the northeast cold region as the object to study the optimal amount of straw returning to the field and irrigation mode by reducing CH, emissions. The static box-gas chromatography field observation method was used. Three irrigation methods including the controlled irrigation, intermittent irrigation and flooding irrigation were set up, as well as three straw returning manage- ment methods of straw-free return (S0: 0 t hm(-2)), low-amount straw returning (S1: 3 t hm(-2)) and high-amount straw returning (S2: 6 t hm(-2)) were analysed on CH, emissions during the growing season of rice in cold land. The results showed that there were large differences in the trends of CH4 emission fluxes treated under the three irrigation modes with rice growth, and this difference mostly occurred in the tillering stage and milk maturity stage of rice growth. Compared with traditional continuous flooding irrigation, controlled irrigation and intermittent irrigation can effectively reduce CH4 cumulative emissions. Straw returning to the field has increased the cumulative emission of CH4 to varying levels. The research results can provide theoretical basis and technical support for alleviating carbon emissions in the cold black soil area of Northeast China.