Farms in our future

There is one thing I see when RVing the future. Shortages of food and fuel that cause our world to go into an emergency. For example, the future price eggs is far greater than now. People our current severe economic crisis, is just the beginning of woe.

What we see up ahead in the distance is people leaving cities due to lack of food. Sadly, on farms there is no food either, but many hope to find a new way to survive. Well, my question is why do farms stop producing food - so far no answer.