I will be able to answer some of your questions in 3 weeks time! I have late March drilled propino with a robust bg pre-em and late April drilled propino with no pre-em all on bg land.Well its just that over in the land of "we can't grow spring crops" its always been the argument that you need to get crops in early on heavy land because of a potential dry summer, that is admittedly in a tillage situation. But what i'm wondering is how far down the calendar year you think you can push it on heavy land for spring cereals. In the west you can still plant decent crops in May but there seems little appetite to do that over your way - I also wonder how that would help against blackgrass and against the cover crops spoiling the establishment, and the negative roundup allelopathy.
I normally drill late March, whilst a local friend is normally late April. The extra yield I get more than covers the extra herbicide spend I have to apply. I don't think that will be the case this year.
We get 600mm/yr and we are finding the spring/early summer is either a drought or a wash out with not much between.
All my covers are killed pre xmas as the idea of covers drying the soil in time for Spring drilling is a seed salesman wet dream, but unfortunately not reality.