双季稻品种根际特征与甲烷排放差异及其关系

为探讨不同水稻品种间甲烷排放差异形成的机制,选取早晚稻各6个品种为供试材料进行大田试验,采用静态暗箱-气相色谱法测定CH4气体.结果表明,早晚稻甲烷排放通量品种间差异显著,全生育甲烷排放通量均值湘早籼24号最高,株两优819最低,相差34. 6%;晚稻种,T优15最高,资优299最低,相差33. 9%.不同双季稻品种间甲烷排放量、单位产量温室效应差异显著.早稻品种的CH4累计排放量介于198. 3～303. 44 kg·hm-2之间,排放量最低是株两优819;单位产量温室效应介于0. 67～1. 40 kg·kg~(-1)之间,陆两优996最低.晚稻品种的CH4累计排放量明显高于早稻,介于291. 93～388. 28kg·hm-2之间,资优299最低;单位产量温室效应介于0. 94～1. 68 kg·kg~(-1)之间,Y两优1号最低.稻田甲烷排放与水稻产量、根冠比、根系孔隙度、土壤溶液Eh值、甲烷浓度、可溶性碳浓度及铵态氮浓度的相关性均达到显著或极显著水平.双季稻品种甲烷排放与水稻根冠比及根孔隙度关系密切,降低早稻品种根系孔隙度或者根冠比可减排甲烷,而晚稻品种则与早稻相反;根际土壤溶液碳氮浓度的降低和Eh值的提高也可减少甲烷的排放.

Differences and Relationship Between Rhizosphere Characteristics and Methane Emissions of Double-cropping Rice Variety

Six field varieties of early rice and late rice were selected as test materials for field experiments to explore the difference in CH₄ emissions among different rice varieties, and Static Obscura-Gas Chromatography was used to determine the CH₄ gas. The results demonstrated a significant difference in the CH₄ emissions flux between early and late rice varieties. The average yield of total fertility CH₄ emissions was highest in Xiangzaoxian 24 and lowest in Zhuliangyou 819, with a difference of 34.6%. Of the late rice varieties, Tyou 15 was the highest and the Ziyou 299 was the lowest, with a difference of 33.9%. Differences in CH₄ emissions and the greenhouse effect of unit yields between different double cropping rice varieties differed significantly. The cumulative CH₄ emissions from early rice varieties ranged from 198.3-303.44 kg·hm^-2, and the lowest emissions were from Zhuliangyou 819. The greenhouse effect per yield ranged from 0.67 to 1.40 kg·kg^-1, and Luliangyou 996 had the lowest emission value. The late-season rice varieties exhibited significantly higher cumulative CH₄ emissions compared to early rice, ranging from 291.93 to 388.28 kg·hm^-2, and Ziyou 299 had the lowest emission value. The greenhouse effect of per yields rice varieties, while the late rice varieties were contrary to early rice. Reducing carbon and nitrogen concentrations in the rhizosphere and increasing Eh values could reduce CH₄ emissions.