This is pretty good. I just have to add and mess with getRenderType and it should be working fine. Also, I'm not sure why you felt the need to register the block within the custom crop class. Don't people usually do that in the main? Anyway, a bit unconventional, but it works.
So how do I add the texture?
EDIT: Oh, never mind. I saw "MODID:" in registerBlockIcons and didn't notice the quotes, so I assumed that was a variable. So I just replaced that part with my mod id and it works fine. Thanks!