Farming can negatively impact the lives of everyday people for numerous reasons. Overcultivation is not good for the land, the people, or the crops and can be dangerous in the long run.
Using chemicals like pesticides can not only be harmful to unwanted bugs, but to people as well. Using too many can easily taint certain crops and make them not fit for eating. Pesticides can also get in the water, like wells or streams, and make people and other wildlife sick.
Overcultivation is not good for the soil and used to be a huge problem back in the day, which is now more regulated today. This was where people would essentially use the same soil so much that it would no longer be able to harbor crops. In the long run, this can even cause dust bowls.
The fluctuating economy also really hurt farmers back in the day. During some periods, it was becoming increasingly hard for farmers to earn money for their crops, as so many people were practicing agriculture during this time, some crops paid little to no money.