[1] The carruca was able to turn over a furrow and it gave an opportunity to utilize the heavier soils of Northern Europe, as well as providing greater drainage; overall an important technological advancement for the medieval agricultural economy.
The scratch plow which preceded the wheeled plough had been ideal for the light sandy soils of Southern Europe, and continued in use in various places, in England, on the continent and also in the Byzantine Empire.
In the section "The cultivated land", subsection "Agricultural systems" (German: Der bewirtschaftete Boden, Anbausysteme) Hoff draw up lines of agricultural development stemming a period of circa 1000 years (2nd - 12th century)—regions mentioned include Denmark, the Netherlands, North-West Germany and England.
[2] The earliest reliable date for the wheeled plough in the Danish region is from the 11th century, at the location Sønder Vium.
[3] In the same section ("Agricultural systems") Hoff gathers textual evidence from the Danish landscape laws indicate usage of the wheeled plough, but also a terminological uncertainty that is later resolved - i.e. reflecting a time of transition.