It's true but how fast and when is it time to plant?
Here is the soil temperature for central Ukraine; by taking a trend line it is possible to estimate the planting times for sunflower and maize.
Assuming a soil temperature requirement of 6 degrees for sunflower and 10 degrees for maize the current trend line indicates we will reach those temperatures on 27th March and 4th April.
But you need to apply some farmer wisdom to the data; from experience we are usually in to the second week in April before the soil has warmed up enough to give confidence at planting.
The temptation is always to go early in a bid to get started and when you have 10kha of planting ahead you can understand why.