Quit harrowing after combine when traded up to STS. 
Nothing but dust from 60 bu wheat.
Fall apply fertilizers with air seeder, then cultivate or harrow even twice in spring to get all straw/loose stubble as even as possible for air drill.
However me worst experience was heavy rain on spring harrowed stubble, way more run off. Remember heavy harrows PACK the soil.
Best emergence of canola is on twice cultivated last fall!
This is on WET black cold soil. We need it blacker.
Nothing but dust from 60 bu wheat.
Fall apply fertilizers with air seeder, then cultivate or harrow even twice in spring to get all straw/loose stubble as even as possible for air drill.
However me worst experience was heavy rain on spring harrowed stubble, way more run off. Remember heavy harrows PACK the soil.
Best emergence of canola is on twice cultivated last fall!
This is on WET black cold soil. We need it blacker.
