Which agricultural field produces maximum methane gas into atmosphere? 

Paddy field 

The correct answer is option 2. Paddy field.

In flooded areas, where there is less oxygen in the soil, rice is cultivated. The microorganisms that create methane from decaying organic waste flourish in anaerobic (lack of oxygen) soils. The majority of this methane diffuses back into the atmosphere through the rice plants, with some of it bubbling to the surface in the process. Consequently, the rice paddy land with the most methane gas emissions into the environment.