Surely if you can consider the second order effects of giving away these extra potatoes for free, then you can also consider the second order effects of not giving them away? And maybe even thinking more about it, consider that they may be going to different markets/people/causes?

Given this example is about 1T batches of potatoes, it could be used by a business that depends on cheap potatoes like a food kitchen, or a business that can absorb the input surge and convert it into a product that can be stored longer term like frozen foods.