[Osier Farm]

I posted a related question in the disease section but I think this fits generally in orchard cleanup. Since a lot of diseases can overwinter in the orchard, what can we do to help get rid of the debris that contains it? I know this may be specific to each problem, but are there some basic rules to follow?

[Osier Farm]

I read that using urea on apple leaves (at the end of the season) can help break them down and prevent apple scab for the next spring. Can urine be used instead, and if so what kind of concentration should I use?