What caused farm prices to drop steadily over time after WWI?

After world war ll, there was a great depression as you should know. caused by a dust bowl which caused crops to be effected into bad ways so farming became hard during this time period. Also they were going through alot of unemployment at the time so yea, it would be farmers facing a rough time or something about how there was unemployment going on and food prices was becoming outragous for people to pay for, so they lowered prices!