Question

Defend the argument that consumers directly impact farm practices

Answer 1

Are we talking about agriculture and livestock farms?
If so, you could say that the consumer (in any case really) controls all aspects of every industry. Without demand there would be no reason for supply. So for example, if a farmer is growing a lot of onions but not a lot of anything else, he most like won't sell a lot of onions. So if the consumers are buying more corn and wheat rather than onions and radishes, then farmers will grow more of those items. This is how consumers directly impact the farming industry