Halacha 1
When is it good to plough, and when is it bad to plough?
How are beit Hillel the more strict opinion? See tosafot moed katan (bavli) 3b s.v. "ad atzeret"
Rav Bar Hayim mentions a comment of haGaon Levi Ginzburg.
Halacha 2
What is s'de hailan?
When can you plough a field with trees?