Please provide evidence to support your assertion. I believe you have reversed the situation. The government pays subsidies to producers so that the price does not fall below an artificial threshold. The subsidies keep the prices high, not low.
Ignorance must be bliss. A few years ago when prices were lower, the usda paid farmers the difference between a target price and the actual price. It had nothing to do with the price that cargill, your local wheat grinder, etc. paid for raw crops mush less the consumer.