The nitrogen cycle is a vital ecological process through which nitrogen is converted into various chemical forms. It involves processes such as nitrogen fixation, where atmospheric nitrogen is converted to ammonia; nitrification, which converts ammonia to nitrites and nitrates; denitrification, the conversion of nitrates back to nitrogen gas; and ammonification, the breakdown of organic matter into ammonia. This cycle is fundamental for maintaining fertility in ecosystems, supporting plant growth, and ensuring the overall health of the environment.