The First Agriculture occurred between 10000 BC and 2000 BC. During the First Agriculture people were hunting and gathering to agriculture and domesticating animals. Humans were changed when they went from uncivilized to civilized. The first crop humans made was a cereal crop.
The second agriculture occurred 1700 to 1900. During the second agriculture changes were made to make farming easier and it took less labor and people & also started using fertilizer. Farming was changed from switching to human labor to machines.
The third agriculture occurred during the late 1900. During the third agriculture many things changed since the first such as everything is evolving machines.Technological advances of agriculture advancement in chemical fertilizer. Farming is now done with mainly machines.
A GMO is an organism whose genome has been altered by the techniques of genetic engineering so that its DNA contains one or more genes not normally found there. GMO gave new crop varites & many other things!