Normally, I would agree this term means "rotating head" or "rotary head", but it doesn't make sense to me in this paragraph. I think it is discussing traditional methods of cultivation along with crop rotation of the potato. However, I'm not too sure about this particular term since I am having trouble finding it in documents that I am sure were written by native speakers of English. See below:

"Crop-livestock systems are looking for new head of rotation since the traditional one has been limited due to quota limitation (sugar beet) or to their negative environmental impact (maize). Therefore, this study aims to illustrate the interest of legumes rich meadows as rotation head in
comparison to a classical head of rotation (maize) and to maize mono-cropping. Indeed such meadows would help to control weeds, to maintain a good soil structure, to support pollinator activity and to supply nitrogen to the rotation. Furthermore, they also improve mixed farm fodder
nitrogen autonomy in comparison to sugar beet crop, an issue of which farmers are more and more aware."

"....junto al girasol y como una opción complementaria se
sitúa el cultivo de colza, la cual se establece como cabeza de rotación, tanto en secano como en regadío"
(source document- www.apea.com.es/pdf/info/publicaciones/memoria-instituciona... translation I found online for this is below)

"Apart from sunflower and as a complementary option, the growing
of rape can be established as rotation head, both in dry and irrigated land."

(from English target document I found online pertaining to sentence listed above www.apea.com.es/pdf/info/publicaciones/institutional-memory...