No reason why farmers can not grow food all year long. There's people all over the world in need of food. The children can not eat money, but they can eat fresh produce, and their Country pay's Our Farmers to grow it!

First of all, there is this thing called winter, farmers can't grow year long and as far as I know almost always have a single crop a year. Throwing money at farmers does give incentive for increased production, however that is not necessarily a good thing. Competitive markets, such as farming, will produce the most beneficial output without government intervention, assuming farmers are taxed based on their contribution to pollution and deforestation.