Assessment of Methane Emission and the Factors That Influence It, from Three Rice Varieties Commonly Cultivated in the State of Puducherry

Abstract

India being the world’s second largest cultivator of paddy, it is very important that the extent of the resulting methane emissions is estimated, and steps are taken to minimize these emissions. Peninsular India is a prime rice-producing region; however, no significant information is available on the contribution of this region to methane emissions, nor are there available studies that show the effect of cultivars, growth seasons, soil characteristics, etc., on methane emissions. As one of the attempts to cover this knowledge gap, emissions of methane from paddy fields, situated in four villages of Puducherry, India, involving three rice cultivars, three soil types and two growth seasons have been studied. All the fields had a continuously flooded pattern of irrigation with water supplied at a rate of 11,500–20,000 m3/ha. Whereas the cultivars ADT 39 and ADT 45 generated the highest methane flux during their reproductive phase, with lesser emission during the vegetative phase and much less during maturity, CO 45 exhibited copious methane emissions during the vegetative phase, with several orders of magnitude lesser emission during the reproductive and the maturity phases. These trends were independent of the location of the field and soil type, though the absolute and the relative values of the emissions varied from location to location. Irrespective of the cultivar, the quantities of methane emission increased linearly with soil temperature across the day but decreased exponentially as soil pH increased beyond 7.

Effect of fertilizer composition and different varieties on yield, methane and nitrous oxide emission from rice field in East Java Indonesia

“…Methane flux decreases after the flowering stage because the photosynthetic rate decreases after seed development, and the availability of assimilates for methane formation decreases (Wihardjaka and Sarwoto, 2015). Previous research has also shown similar results, with the highest methane fluxes observed during the vegetative and early reproductive phases (about 25 days after showing), followed by a decline during the flowering and maturity phases (Chandrasekaran et al, 2022).…”

“…Additionally, previous research has shown that rice variety differences significantly affect greenhouse gas emissions. Shortduration and water-efficient rice varieties can reduce CH 4 emission fluxes under low-water irrigation conditions (Chandrasekaran et al, 2022). In this study, the Way Apo rice variety produced lower CH 4 emissions compared to Inpari 32 under the P1, P3, and P4 fertilizer variations.…”

Mitigating atmospheric methane emissions from Asian rice fields: a review of potential and promising technical options

“…Seasonal temperature variation strongly affects methane flux during the plantation period in various rice field locations in Japan (Yagi & Minami, 1991). Similarly, Chandrasekaran et al (2022) reported that methane emissions increase linearly to the increase in soil temperature in India. Temperature affects methane emissions through anaerobic digestion reactors, which are done by mesophilic (20~42°C) or thermophilic (42~75°C) organisms such as methanogens (Parawira, 2004).…”

“…The next factor that influences methane production is temperature because temperature changes in the soil would affect the methanogens (Schulz et al, 1996;Chandrasekaran et al, 2022). Seasonal temperature variation strongly affects methane flux during the plantation period in various rice field locations in Japan (Yagi & Minami, 1991).…”

Spatiotemporal patterns and drivers of greenhouse gas fluxes in the sub-tropical wetland ecosystem of Indian Himalayan foothill

“…Studies have reported that CO 2 , CH 4 , and N 2 O are the topmost three natural greenhouse gases, responsible for 64%, 17%, and 6% of the total radiative forcing (Myhre et al 2013;Tran et al 2017). CO 2 is often given the most attention due to the contributions from human activity to its rising levels; however, CH 4 and N 2 O have about 34 and 300 times higher global warming potential, respectively, than CO 2 (Gri s et al 2017; Chandrasekaran et al 2022).…”