It's the same root as in
*kWe-kWl-o- 'wheel', but *kWel- meant 'go
round in circles', not 'turn' in the sense you suggest. With so many languages
at your fingertips you should know that Latin colare means
'cultivate, tend, attend to'. It may also mean 'till', but the original sense
was 'go about/around sth'. Piotr
Piotr, it's not colare AFAIK,
but colere (cultura etc.).