Rape and barley are much higher priority and higher quantity than wheat or oats. And all crops need sulphur except where there has been a lot of organic manure applied over the years.
Rape – rate is driven by GAI and how much canopy growth you need to drive. Get advice on this.
Winter barley – apply between 50kg and 70kg N/ha depending on rotation and crop. Apply more where the crop is very yellow.
Winter wheat and oats – apply 30kg to 50kg N/ha to keep crops ticking over.
Try and balance N and P&K requirements. You can apply too much N at this time– so be careful.