不同稻—麦栽培管理方式对稻季农田温室气体排放的影响

Effects of management approaches on greenhouse gas emissions in the rice-wheat field

通过研究水稻品种与种植方式对水稻生长阶段稻田CH4,N2O,CO2排放的影响,探讨适宜浙江的低碳环保型稻—麦栽培模式。结果表明,麦季和稻季栽培方式明显影响水稻生长阶段稻田温室气体排放通量,麦季和稻季均免耕的处理,3种温室气体排放量均最大,显著高于稻麦旋耕的处理。不同类型水稻品种温室气体排放量有差异,杂交品种在分蘖期、拔节孕穗期和灌浆期CH4,N2O,CO2的总排放量和单位籽粒产量的排放量低于常规水稻,差异达显著水平。土壤水势影响稻田温室气体的排放量,减少灌溉有利于稻田CH4,CO2排放量的降低,但过低的灌溉量会导致N2O排放通量的显著增加和籽粒产量的明显下降。因此,通过选用杂交水稻品种,采用旋耕栽培方式,并配合土壤水势为-20～-30 kPa(田面无水层,土壤湿润无裂痕)的灌溉量,可显著减少稻田温室气体的排放。

In order to explore the suitable management approaches for low-carbon agricultural production in Zhejiang Province, the effects of rice varieties and planting pattern on CH4, N2O and CO2 emission were investigated.It was shown that the cultivation method of wheat and rice significantly influenced greenhouse gas emission during the rice season.Under the management of no tillage , the greenhouse gas emission was the largest , and was significantly higher than the management of rotary tillage .Rice varieties also influenced greenhouse gas emission .The total emissions of CH4 , N2 O, CO2 and emissions per unit grain yield of hybrid rice varieties were significantly lower than the conventional rice varieties in the tilling stage , jointing-booting stage and filling stage .Besides, soil water potential could impact greenhouse gas emission .Reducing rice irrigation decreased CH 4 and CO2 emission in the rice field.But, the excessive lowered irrigation would significantly increase N 2 O emission yet decrease the grain yield .In conclusion , the greenhouse gas emission in rice field could be significantly reduced by the combined management＆amp;nbsp;approaches , including applying hybrid rice variety and rotary tillage , and keeping the soil water potential at -20--30 kPa.