Methane Emission Dynamics in Organic and Conventional Rice Cultivation Systems under Field Condition

Abstract

Methane (CH 4 ) emissions from irrigated rice fields are a major source of agricultural greenhouse gas emissions due to anaerobic conditions that stimulate methanogenesis. Organic rice cultivation combined with appropriate water management has been considered a more sustainable cultivation approach, although differences in nutrient and water management may affect methane dynamics. This study aimed to evaluate differences in CH 4 emissions between two field-relevant rice cultivation systems and examine their associated environmental and soil conditions. Field observations were conducted from August to December 2025 in Pagerageung, Tasikmalaya, comparing organic rice managed with Alternate Wetting and Drying (OR-AWD) and conventional rice under continuous flooding (CO). Methane emissions were measured alongside soil electrical conductivity (EC), pH, temperature, moisture, and water level throughout the growing season. Seasonal CH 4 emissions were 171.93 kg ha −1 season −1 in OR-AWD and 394.12 kg ha −1 season −1 in CO, representing 56.4% lower emissions in the OR-AWD system. The lower emissions were associated with differences in water-level dynamics and soil environmental conditions under the two cultivation systems. These findings highlight the potential of integrated water and nutrient management in improving the methaneemission performance of rice cultivation systems under field conditions.