Effects of Soil Temperature, Flooding, and Organic Matter Addition on N(2)O Emissions from a Soil of Hongze Lake Wetland, China

The objectives of this study were to test the effects of soil temperature, flooding, and raw organic matter input on N(2)O emissions in a soil sampled at Hongze Lake wetland, Jiangsu Province, China. The treatments studied were—peat soil (I), peat soil under flooding (II), peat soil plus raw organic matter (III), and peat soil under flooding plus organic matter. These four treatments were incubated at 20°C and 35°C. The result showed that temperature increase could enhance N(2)O emissions rate and cumulative emissions significantly; moreover, the flooded soil with external organic matter inputs showed the lowest cumulative rise in N(2)O emissions due to temperature increment. Flooding might inhibit soil N(2)O emissions, and the inhibition was more pronounced after organic matter addition to the original soil. Conversely, organic matter input explained lower cumulative N(2)O emissions under flooding. Our results suggest that complex interactions between flooding and other environmental factors might appear in soil N(2)O emissions. Further studies are needed to understand potential synergies or antagonisms between environmental factors that control N(2)O emissions in wetland soils.