Systematic refers to any type of agriculture that is done purposefully and orderly.
Systematic agriculture refers to any type of agriculture that is done purposefully and orderly. You could argue that agriculture is by its own definition systematic. Agriculture is the production of crops or livestock for food or other products such as eggs or wool.
Agriculture developed in several places across the world at slightly different times. It is generally agreed that it began during what is referred to as the Neolithic Revolution. This was a time when humans started settling down permanently.
Because they were no longer following herds of animals or moving with the changing of the seasons as certain species bloomed they needed to find other ways of obtaining their food. Agriculture was one solution. Humans started changing and controlling their own environment in order to produce needed goods and materials.
To read more about the history and development of agriculture check out this resource from National Geographic.