Question: What process releases nitrogen gas into the atmosphere?

context: The nitrogen cycle is the biogeochemical cycle by which nitrogen is converted into multiple chemical forms as it circulates among atmosphere, terrestrial, and marine ecosystems. The conversion of nitrogen can be carried out through both biological and physical processes. Important processes in the nitrogen cycle include fixation, ammonification, nitrification, and denitrification. The majority of Earth's atmosphere (78%) is atmosphere nitrogen, making it the largest source of nitrogen. However, atmospheric nitrogen has limited availability for biological use, leading to a scarcity of usable nitrogen in many types of ecosystems.
question: What is the main process releases nitrogen gas into the atmosphere?
short_answers: Nitrogen cycle
context: Denitrification is the reduction of nitrates back into nitrogen gas (N), completing the nitrogen cycle. This process is performed by bacterial species such as "Pseudomonas" and "Paracoccus", under anaerobic conditions. They use the nitrate as an electron acceptor in the place of oxygen during respiration. These facultatively (meaning optionally) anaerobic bacteria can also live in aerobic conditions. Denitrification happens in anaerobic conditions e.g. waterlogged soils. The denitrifying bacteria use nitrates in the soil to carry out respiration and consequently produce nitrogen gas, which is inert and unavailable to plants.
question: What process releases nitrogen gas back into the atmosphere?
short_answers: Denitrification

Answer: The nitrogen cycle is the biogeochemical cycle by which nitrogen is converted into multiple chemical forms as it circulates among atmosphere, terrestrial, and marine ecosystems. Important processes in the nitrogen cycle include fixation, ammonification, nitrification, and denitrification. The majority of Earth's atmosphere (78%) is atmosphere nitrogen, making it the largest source of nitrogen. Denitrification is the reduction of nitrates back into nitrogen gas (N), and back into the atmosphere, completing the nitrogen cycle.