Plants need nitrogen to grow. The use of chemical fertilizers since the early 20th century (à Haber-Bosch process) has led to the agricultural revolution with increasing high-quality yields. Without nitrogen fertilizers crops reach less than half of their potential yield.
Even though plants have access to nitrogen from many naturally occurring sources like soil, high yields and high quality are not possible without the application of mineral and/or organic nitrogen-containing fertilizer. However, only about 50% of the applied nitrogen is absorbed by the plants, and the rest is bound to the soil or lost as ammonia, nitrous oxide and nitrogen gas to the air and/or nitrate to the water, with a negative effect on the environment.