Due to recent drought, a farmer has lost quite a bit of soil on his fields because?

Well ... i think that when drying up, the soil breaks down into a powder, but i think you know that already. but maybe when the water all evaporates, you know it doesn't leave all of the dirt behind. like when saltwater is evaporated it doesn't leave behind the salt. so my best guess is that bits of soil was brought up wit the water