水稻根际特性与甲烷排放相关性研究

Study on the Correlation Between Rhizosphere Characteristics and Methane Emission in Rice

探讨不同水稻品种的根际特性差异,为水稻品种筛选和稻田甲烷减排提供基础依据。以不同甲烷排放量的早晚稻品种为供试材料,采用大田小区试验,观测水稻根冠比、根体积、根孔隙度、根系活力以及根际土壤中蔗糖酶活性、脲酶活性指标,与甲烷排放通量做相关性分析。结果表明:早稻和晚稻的甲烷排放通量在季节变化上较一致,分蘖期最高,随着水稻的生长逐渐降低,至生长后期(乳熟期)几乎没有甲烷的排放。早晚稻根系及根际土壤特性在不同生育时期均表现出不同差异性。早稻的甲烷排放通量与根冠比有极显著正相关关系(P<0.01),与根际土壤蔗糖酶活性有极显著负相关关系(P<0.01);晚稻甲烷排放通量与根冠比、根孔隙度有极显著正相关关系(P<0.01),与根体积有极显著负相关关系(P<0.01),与根系伤流量有显著的正相关关系(P<0.05)。可知,根冠比是影响早晚稻品种甲烷排放的关键根际特性。

To explore the differences in rhizosphere characteristics of different rice varieties,which provided a basis for rice variety screening and rice field methane emission reduction.Early and late rice varieties with different methane emissions were used as test materials.Through the field experiment,the root-shoot ratio,root volume,root porosity,root activity and the activities of invertase and urease in rhizosphere soil were observed,and correlation analysis with methane emission flux.The results showed that the methane emission fluxes of early rice and late rice were consistent in seasonal changes,the highest in the tillering stage,and gradually decreased with the growth of rice,and there was almost no methane emission in the late growth period(milk maturity).The root system and rhizosphere soil characteristics of early rice and late rice showed different differences at different growth stages.There was a significant positive correlation between methane emission flux and root-shoot ratio in early rice(P<0.01),and a significant negative correlation with selenase activity in rhizosphere soil(P<0.01).There was a significant positive correlation between methane emission flux and root-shoot ratio and root porosity in late rice(P<0.01),and a significant negative correlation with root volume(P<0.01).Late rice methane emission flux had a significant positive correlation with root injury flow(P<0.05).It can be seen that the root-to-root ratio is a key rhizosphere characteristic that affects methane emissions from early and late rice varieties.