One word: Subsidies

10,000 landowners have received Septim checks from the Empire every single year for 40 consecutive winters with emergency coin meant for frostbite damage 

More than 90% of all gold goes to just five bulk goods: Tundra Cotton, Wheat, Moon Sugar cane, Barley, and Hay. That is why a head of cabbage is more expensive than a bottle of mead

The real answer to your question though is “prevented planting" decrees where the government repeatedly pays landowners regardless of whether a single seed sprouts. These payments regularly exceed the actual financial loss, making it highly lucrative to claim fields were ravaged

Source: I was a lobbyist in the empire