CAJ | 학술논문

采用静态箱法和田间小区试验,研究了常规稻田和覆膜旱种稻田水稻全生育期 CH4的排放规律,探讨了温度和水分与稻田 CH4排放的关系.结果表明:覆膜旱种稻田的甲烷排放量明显低于常规水田的排放量,常规水田的甲烷累计排放通量为20.38 g/m2,覆膜旱种稻田为2.46 g/m2,水稻覆膜旱种后甲烷排放量降低了88%.常规水田 CH4排放峰期持续了35 d,覆膜旱种稻田 CH4排放峰期为25 d,两者在 CH4排放高峰期的排放量分别占整个生育期累计排放量的72%和97%.覆膜旱作稻田 CH4排放量降低,主要表现在最大排放峰值降低和排放峰持续时间缩短.土壤温度(5 cm 处)和水分与水稻生育期稻田甲烷的排放有显著正相关.CH4排放通量大于1.0 mg·m-2·h-1主要集中在土壤质量含水率高于36.25%的区域,在土壤质量含水率小于36.25%时,常规稻田和覆膜旱种稻田都只有少量 CH4排放.
채용정태상법화전간소구시험,연구료상규도전화복막한충도전수도전생육기 CH4적배방규률,탐토료온도화수분여도전 CH4배방적관계.결과표명:복막한충도전적갑완배방량명현저우상규수전적배방량,상규수전적갑완루계배방통량위20.38 g/m2,복막한충도전위2.46 g/m2,수도복막한충후갑완배방량강저료88%.상규수전 CH4배방봉기지속료35 d,복막한충도전 CH4배방봉기위25 d,량자재 CH4배방고봉기적배방량분별점정개생육기루계배방량적72%화97%.복막한작도전 CH4배방량강저,주요표현재최대배방봉치강저화배방봉지속시간축단.토양온도(5 cm 처)화수분여수도생육기도전갑완적배방유현저정상관.CH4배방통량대우1.0 mg·m-2·h-1주요집중재토양질량함수솔고우36.25%적구역,재토양질량함수솔소우36.25%시,상규도전화복막한충도전도지유소량 CH4배방.
To investigate methane fluxes in traditional paddy field and film mulching upland for late rice growth in South China, field experiment were conducted and gas sampling the closed-chamber technique were applied. The methane cumulative fluxes and global warming potential (GWP) from film mulching upland and traditional paddy field during rice growth were compared to estimate the contribution of methane fluxes from film mulching upland to greenhouse effect. Soil samples in 0-20 cm layer were collected to measure the soil water content (w/w). The thermometer was buried at 5cm soil depth in closed-chamber for gas sampling after rice transplanting. Soil temperature was obtained by the thermometer when methane was sampled. The relationships of soil moisture and soil temperature with methane fluxes were studied. Results showed that methane emitted were concentrated during the vegetative growth stage of rice both paddy field and film mulching upland. However methane emission in paddy field concentrated in former 35 days after rice transplanting with methane cumulative flux of 14 779.97 mg/m2. Methane emission in film mulching upland concentrated in former 25 days after rice transplanting with methane cumulative flux of 2 372.27 mg/m2. The percentage of CH4 cumulative flux in emission peak period and total cumulative flux in the paddy field and film mulching upland were 72% and 97%, respectively. Methane fluxes in film mulching upland were significantly lower than that in traditional paddy fields. Methane cumulative flux in film mulching upland declined by 88% compared to paddy field due to the fact maximum emission peak reduced and the emission peak period shortened. The GWP (CO2 equivalent fluxes) of methane was 468.72 g/m2 in paddy field, but 56.48 g/m2 in film mulching upland. Thus the contribution of methane fluxes to greenhouse effect in film mulching upland was lower than that in paddy field. Soil temperature and soil moisture at 5 cm soil depth had significant positive correlation with methane fluxes during the rice growth stage, respectively. The area of methane flux more than 1.0 mg·m-2·h-1 existed in the area of the soil water content (w/w) higher than 36.25%, and few methane in both paddy field and film mulching upland was emitted when soil water content was less than 36.25%.