Answer:
Nitrogen from the air can enter soil through a process called nitrogen fixation, which is the conversion of atmospheric nitrogen into a form that can be taken up by plants. This process can occur through several ways, including:
Biological nitrogen fixation: Certain bacteria and other microorganisms can convert atmospheric nitrogen into ammonia through a process called nitrogen fixation. This ammonia can then be converted into other forms of nitrogen that plants can use, such as nitrate or ammonium.
Lightning: During thunderstorms, lightning can convert atmospheric nitrogen into nitrogen oxides, which can then be dissolved in rainwater and enter the soil.
Industrial nitrogen fixation: Human activities such as the production of fertilizer and the combustion of fossil fuels can also lead to the release of nitrogen compounds into the atmosphere, which can eventually be deposited onto soil.