This research was to investigate the amount of methane emission in the organic paddy field (wet-season rice), direct-seeding method around Tung Kula Rong Hai, the Northeast of Thailand during planting and harvest season and to examine the influential variables such as the growth, types of soil, temperature, height of rice plant, density of rice plant and the water level in the paddy field. The study was conducted in the paddy field of Khao Dawk Mali 105 in 4 stations. The results of the study revealed that; in period 1, from the period of seeding to tillering, CH₄ Flux is in the range of 0.193–1.383 mg CH₄ m⁻² hr⁻¹ or 0.728 ± 0.429 mg CH₄ m⁻² hr⁻¹ in average; in period 2, from tillering to ripening, CH₄ Flux is 1.311–2.446 mg CH₄ m⁻² hr⁻¹ with the average of 1.938 ± 0.359 mg CH₄ m⁻² hr⁻¹; In period 3, from ripening to harvesting, CH₄ Flux of 0.873–2.235 mg CH₄ m⁻² hr⁻¹ with the average of 1.575 ± 0.351 mg CH₄ m⁻² hr⁻¹

Regarding the result, the amount of methane flux has increased according to the age span and the growth of the rice. Besides, there were factors affecting the escalation of the gas release: the water level in the paddy field which means the emission will be decreased when the water is managed to drain prior to harvest stage, considering the factors of the height of rice plant in the paddy field, the smaller number and lower rice plant height is, the lesser methane is emitted. However, in term of the temperature, the higher temperature is, the more methane increases.

Consequently, the study of methane flux from rice paddy as well as its factors contributes to the farmers' ability to manage their paddy fields effectively. This will lead to low organic carbon farming and reducing greenhouse gas (GHG) emissions in agricultural sectors.