First Agricultural revolution (between 10,000 - 2000 b.c)- this is when people started to plant crops and domesticate animals instead of gathering crops and hunting animals for food. It's also known as the "Neolithic Revolution". People started to plant crops such as wheat. People used the method slash and burn so the soil could have a lot of nutrients to plant crops the next time.
Second Agricultural revolution (1700s)- it happened in Western Europe in about the 1700s. It introduced horse collars, seed drills and tractors. It changed farming by producing and planting crops faster and more efficient. It also introduced a system called the crop rotation, it's when farmers choose one crop to grow one year and a different crop another year choose a different crop to grow the whole year. New crops were grown such as corn and potatoes for mostly livestock. Von Thunen makes a model about spatial character of economic activity.
Third agricultural revolution- before people used pesticides to kill weeds and insects, now people started creating GMOs, biotechnology and more intense mechanization and is also known as the "Green Revolution". This was the start an increase in grain production. This happened throughout the 1970's and 1980's. Farming changed by putting gmo on crops and 1 farmer could feed around 126 people but before 1 farmer could only feed about 6 people. But it also caused pollution from the diesel tractors.
Genetically modified organisms are organisms that have different genes from a different organism. The changes to farming are that farmers won't use as much pesticides but will use GMOs so they won't die as easily. The pros were that it's more efficient and crops can be resistant to weeds, insects and pesticides, also more resistant from heat or cold (mostly used on corn, soybeans and cotton).
Summary: Humans have changed the ways how we obtain food and methods for farming crops. Before the First Agricultural Evolution, humans were hunting food and gathered plants. Around 11,000 b.c the First Agricultural Evolution was happening, humans were beginning to domesticate animals and plant their own crops. Humans were planting wheat and domesticated oxen, cattle for milk and sheep for cotton. Around in the 1700s, the second agricultural evolution was starting. People invented the seed drill, horse collar and the plow so farming could be more faster and more efficient. Before these things were invented, people tilled the land themselves and planted the seeds by hand. This changed farming because farmers could expand their land, they started the mono culture which was planting the same crop the whole year and they changed the methods for fertilization and harvesting. During the 1970s, the Third Agricultural revolution was beginning, people were making more intense mechanization, people invented GMOs and diesel engine tractors. During this period, farmers expanded more land and could harvest crops way faster. Before farmers had to use the plow to till land. GMOs helped crops be more resistant to weeds, insects and the harsh weather which allowed farmers to harvest more food than ever. Before one farmer could only feed about 6 people, now one farmer can feed around 126 people. But GMOs had a negative side too, people that ate foods with GMOs in it had a higher risk of getting cancer, allergies and could get them obese after consuming a lot of it.