冬季水分管理方式对稻田CH4排放量的影响

在西南农业大学和华南农业大学农场的田间试验表明,长期淹水是我国西南地区冬灌田水稻生长期CH₄排放通量高于一般水田的主要原因.土壤淹水前连续干燥的时间越长,水稻生长期CH₄排放通量越低,但这种作用仅能维持一季水稻生长期.冬灌田冬季排干,种植冬小麦,次年水稻生长期CH₄平均排放通量可减少63～72%.如果我国西南地区冬灌田的水利设施能够得到有效改善,改冬灌为冬排,一年一季水稻为一水一旱,将可提高该类土壤生产力和大大减少我国稻田CH₄排放总量.

Influence of water management in winter crop season on CH4 emission during rice growing season

Field measurements conducted in the farms of Southwest Agricultural University and South China Agricultural University showed that long term flooding was the main factor causing high CH₄ emission during the rice growing period in Southwest China. The longer the soil was dried before flooding, the less the CH₄ emission during the rice growing period. But the effect was available only for one rice crop season. The mean CH₄ emission over rice growing period was reduced by 63～72% by draining traditional winter-flooded rice fields and planting winter wheat. If the drainage and irrigation system could be improved significantly and the crop rotation of one flooded rice and one upland winter crop could be introduced instead of one rice crop in the area of the traditional winter-flooded soils, the soil production could be raised and total CH₄ emission from rice fields could be reduced significantly.