不同水稻品种甲烷排放与土壤酶的关系

Relationship between methane emissions and soil enzymes of different rice varieties

为明确不同水稻品种甲烷(CH4)排放差异形成与根际土壤过氧化氢酶、脲酶活性的关系,选取早稻晚稻各3个品种为大田供试材料,采用密闭静态暗箱法收集CH4气体,监测早稻晚稻不同品种CH4排放动态,以及不同品种在主要生育时期根际土壤的过氧化氢酶、脲酶活性,并对不同水稻品种CH4排放与两种酶活性进行了线性回归分析。结果表明:双季稻品种CH4排放差异显著,晚稻CH4累积排放量明显高于早稻,早稻品种中CH4累积排放量以湘早籼24号最高,株两优819最低,相差31.78%;晚稻以湘晚籼17号最高,Y两优1号最低,相差17.31%。双季稻品种在不同生育期根际土壤的过氧化氢酶、脲酶活性存在差异,早稻过氧化氢酶活性在孕穗期最高,晚稻过氧化氢酶、双季稻脲酶活性均在分蘖期最高;双季稻田CH4排放与脲酶正相关,达到极显著水平(P<0.01),与过氧化氢酶正相关,达到显著水平(P<0.05)。综上,双季稻品种甲烷排放与水稻根际土壤过氧化氢酶、脲酶关系密切,降低水稻品种根际土壤的过氧化氢酶、脲酶活性有利于稻田CH4减排。

To clarify the relationship between methane emissions and soil enzymes on different rice varieties, we used three field varieties of early rice and late rice as test materials to collect methane by closed and obscure static box method for field experiment,monitored the dynamics of methane emissions from different varieties of early rice and late rice, determinated the catalase activity and urease activity of different methane emission rhizosphere soil. The relationship between methane emission and enzyme activities was analyzed by linear regression analysis. The results showed that:there was a significant difference between early rice and late rice varieties in methane emission. The cumulative methane emission of early rice varieties was the highest in Xiangzaoxian 24 and the lowest in Zhuliangyou 819, with a difference of 31.78%. The late rice Xiangwanxian17 was the highest, and the Y liangyou1 was the lowest, with a difference of 17.31%. The cumulative methane emissions of late rice varieties were significantly higher than that of early rice. Catalase activities of early rice were highest at booting stage, catalase activities of late rice and urease activities of early rice and late rice were highest at tillering stage. The activity of catalase and urease in rhizosphere soil of different early rice and late rice varieties were different at different growth stages. The positive correlation between methane emission and urease in double-cropping rice field reached an extremely significant level(P<0.01), and the positive correlation with catalase reached a significant level(P<0.05). In conclusion, methane emission of rice varieties is closely related to catalase and urease in rhizosphere soil of rice, reducing the activity of catalase and urease in soil is beneficial to reducing methane emission in rice field.