Influence of Wheat Straw Buried in Ditches on CH₄ and N₂O Emissions From Rice Fields

To study the effect of wheat straw buried in ditches on CH₄ and N₂O emissions from rice fields,a field experiment was conducted in 2006.CH₄ and N₂O fluxes were measured using closed-chamber technique in three treatments（no wheat straw applied,wheat straw evenly incorporated into the topsoil and wheat straw buried in ditches）.Results show that in the ditch area with wheat straw buried,the mean CH₄ flux was significantly higher than that from the area with wheat straw evenly incorporated into the topsoil,while the mean N₂O flux from the ditch area was significantly lower than that from the area with wheat straw evenly incorporated into the topsoil.The total seasonal CH₄ emission from the area with wheat straw buried in ditches was 4.07 times as that from the area with no wheat straw applied,but there was no significant difference in total seasonal CH₄ emission between the area with wheat straw buried in ditches and the area with wheat straw evenly incorporated into the topsoil.The total seasonal N₂O emission from the area with wheat straw buried in ditches was 70% as that from the area with no wheat straw applied,and 3.14 times as that from the area with wheat straw evenly incorporated into the topsoil.