The fundamental economic problem is that demand is very inelastic. When you draw a supply-demand curve for food it looks very close to a vertical line, people do not buy significantly more food when you make it cheaper, people do not buy significantly less food until they run out of money.
The implication is that even slight excesses result in rock bottom prices, and even slight shortages result in very high prices. This volatility is bad for everyone. Therefore the government steps in with subsidies to even out how much farmers get, and to guarantee a surplus to avoid ruinous food prices for consumers.
But there is simply no good way to do this without perverse consequences somewhere...
The implication is that even slight excesses result in rock bottom prices, and even slight shortages result in very high prices. This volatility is bad for everyone. Therefore the government steps in with subsidies to even out how much farmers get, and to guarantee a surplus to avoid ruinous food prices for consumers.
But there is simply no good way to do this without perverse consequences somewhere...