Methane emissions from rice fields: Effect of plant height among several rice cultivars

Abstract

The effect of rice cultivar and plant height on methane (CH4) emission from rice fields was studied from data of 8‐year field experiments. Field experiments were conducted from 1989 to 1996 at the Texas A & M University Agricultural Research and Extension Center near Beaumont, Texas. Eleven rice cultivars and three soil types were involved. The results of this study showed the following: 1) Rice cultivar choice slightly influenced the day‐to‐day seasonal pattern of methane emission, but it had a significant effect on the seasonal total methane emission. The average seasonal methane emission is 22.8 g CH4 m−2 for high‐emitting cultivars (Mars and Della), ranging from 8.0 to 41.0 g CH4 m−2 and 17.7 g CH4 m−2 for low‐emitting cultivars (Lemont, Labelle, Lebonnet, Dawn, Katy, IR 36, Cypress, and Jasmine), ranging from 1.7 to 28.4 g CH4 m−2.) Seasonal methane emission has a positive linear correlation with postheading rice plant height. The correlation coefficient r2 is 0.736 (n = 24, and p < 0.05). In this paper we suggest that plant height may be a good criteria in choosing cultivars for mitigation of methane emission. More importantly, it provides a potential method for estimating methane emission from regional or global rice paddies as plant height can be evaluated by remotely sensed imagery.