The gas used in the production of fertilizers is ammonia. Ammonia is a critical component in synthetic fertilizers, which are essential for modern agriculture. The Haber-Bosch process, developed in the early 20th century, allows for the industrial synthesis of ammonia from nitrogen and hydrogen. This process has revolutionized farming by providing a reliable source of nitrogen, which is vital for plant growth. Besides ammonia, other compounds such as urea and ammonium nitrate also contribute to nitrogen-based fertilizers, enhancing crop yields and food production globally.