I love the idea of writing about backpacking - especially if you can weave in meaningful comments about BYU's educational aims. I've heard that last bit's really, really important.
Why backpacking? It's interesting! How many other people are going to write about backpacking? Readers will notice. Might get him a second look. Also, I once heard an admissions guy at some "elite" school advise students not to repeat themselves in their applications/essays. Could he write about different aspects of farm life? Sure! But it might be a good idea to shake things up a little.
Again - this time with emphasis - I KNOW NOTHING about the admissions process. I'm just shootin' the breeze here. (Okay, my daughter did just complete her own application. So I'm interested. But I still don't really "know" anything.)