Which of the following gases is released from rice fields in the most prominent quantities ?

Methane (CH4) is the most prominent gas released from rice fields due to the anaerobic conditions created by flooded paddy cultivation. In these inundated environments, oxygen is prevented from penetrating the soil, which facilitates the growth of methanogenic bacteria that decompose organic matter and release methane [c1][t10]. Rice cultivation is a significant anthropogenic source, contributing approximately 10-12% of global methane emissions [t3][t4]. While other greenhouse gases like nitrous oxide and carbon dioxide are also associated with rice farming—often due to fertilizer use or residue burning—methane remains the primary emission directly linked to the flooded soil environment [t1][t7]. Studies indicate that paddy fields are considered one of the most important sources of atmospheric methane, with global emission rates estimated between 20 to 100 Tg/yr [t6]. Consequently, methane is the most characteristic and significant gas produced during the rice growing cycle.

Sources

1. [1] Environment and Ecology, Majid Hussain (Access publishing 3rd ed.) > Chapter 7: Climate Change > 2. greenhouse gases > p. 11
2. [2] https://www.unep.org/news-and-stories/story/methane-emissions-are-driving-climate-change-heres-how-reduce-them
3. [3] https://pmc.ncbi.nlm.nih.gov/articles/PMC12432061/
4. [4] https://www.osti.gov/servlets/purl/959124
5. [5] https://blogs.worldbank.org/en/eastasiapacific/greening-rice-we-eat