from my experience, broadcasting over unprepared soil you would want around 200 lbs per acre of oat or wheat when spread alone, with your mix I would look at at least 100lbs of each wheat and oats, and 3-5 lbs of clover and around 2-3 lbs of turnip per acre. plan on adding another 50 lbs of wheat and or oats each 3-4 weeks after germination top sown into what sprouts the first time around along with 200lbs of triple 13 or 15 at this time to. its best to do this over seeding the day of or the day before a good rain.
These are very generic rates for no till, you want to seed heavy as your germination/loss to birds will be high also. If you have a way to run a roller or drag over the seed once applied it will help with the seed to soil contact.
