Agricultural engineering is the application of engineering principles to any process
associated with producing agriculturally based goods and management of our natural
resources.  

The discipline concerns itself with development of labour-saving, farm machines, farm buildings, irrigation and drainage systems, and processes for preserving and converting agricultural products to useful feed, and fibre products. Thus we can see that contrary to the erroneous understanding of many people, agricultural engineering is not synonymous to tractorization.

Why people have thought that agricultural engineering is synonymous to tractorization is because the earliest engineering intervention had much to do with the reduction of drudgery with the use of tractor, for a very long time.