土壤质地、温度和Eh对稻田甲烷排放的影响

EFFECTS OF SOIL TEXTURE, SOIL TEMPERATURE AND Eh ON METHANE EMISSIONS FROM RICE PADDY FIELDS

本文报道在田间条件下，土壤质地、温度和Eh影响稻田CH4排放通量的研究结果。中国科学院封丘生态试验站的小区试验表明，在当地常规水分管理即间歇灌溉条件下，供试小区稻田的CH4平均排放通量仅为0.16-1.86mgCH4/m2h。通过成对数据t检验及用二项分布统计方法分析表明，供试条件下，土壤温度和Eh（5cm）对稻田CH4排放通量日变化有极显著影响，但它们不是决定稻田CH4排放通量季节变化的主要因素。土壤质地对稻田平均CH4排放通量具有显著的影响作用，1993年和1994年二年的结果表明，粘质土壤排放的CH4显著或极显著低于壤质和砂质土壤。但砂质和壤质土壤CH4平均排放通量的比较结果在年际之间不一致。

Effects of soil texture, soil temperature and soil Eh at 5 cm on CH4emissionsfrom rice paddy fields were invetigated in the Fengqiu Ecological Experimental Station,Chinese Academy of Sciences, under field conditions in 1993 and 1994. The resultSshowed that CH4 emissions from the studied fields were low, ranging from 0.16-1.86mg CH4 / m2 h in the mean fluxes throughout the Period of rice growth underintermittent irrigation. Soil temperature and soil Eh might not be dominant factorsinfluencing the patterns of seasonal variation of CH4 flux from the rice paddy fields,but they affected the diurnal variations significantly. The CH4 emissions from clayeyrice paddy fields were significantly lower than those from the sandy and loamy paddyfields in 1993 and 1994. The highest CH4 emission was observed in the loamy fieldin 1993 but in the sandy field in 1994.