In the 20th century, the work of humans and animals (like horses and oxes) was gradually fading in favor of farm machinery. Machines such like tractors, cultivators, transplanters or combine harvesters have greatly increased food output, which in turn allowed more people to be fed. Mechanized agriculture also included of more advanced technology, like aircraft or satellite navigation. Another important aspect of the 20th century agriculture was development of synthetic fertilizers, as well as pesticides originating from the military industry. Food yield skyrocketed worldwide, but wide-scale enviromental damage was inevitable.