Effect of environmental conditions on methane production and emission from paddy soil

Methane production and emission from paddy soil in laboratory experiments were affected by sterilization, temperature, organic matter supplementation, urea application, oxygen concentration, water content, soil pH and light intensity. Methane production was negligible in sterilized soil, whereas each gram of natural soil produced a daily maximum of 344 μg methane. There were two methane production peaks, one at 37°C, the other at 60°C. There was a positive linear correlation between methane production and incubation temperature from 15 to 37°C, and a negative linear correlation between 37 and 50°C. Methane production increased with the amount of rice straw supplementation. Green manure, corncob, xylan, avicel and compost application had a stimulating effect on methane production, whereas glucose, sucrose and urea supplements were inhibitory. Anaerobic conditions and water flooding on the surface of soil favoured methane emission.