French to English Other Agriculture Sheep farming

I’m not quite sure how best to translate “assiette” in the following context - I got “basis for calculation” from IATE… It also gave "base", but that seems to be specifically used for tax. The text is talking about premiums for sheep farmers. I’m not very familiar with the subject, so I’m not sure whether it sounds right or not! Can anyone help?


Un Article 69 modifié, qui permette un prélèvement de 15 ou 20% sur une assiette élargie à l’ensemble des secteurs, et dont l’implémentation serait sinon une obligation, du moins une forte incitation européenne, nous semble une voie intéressante.

A revised Article 69, which would allow a levy of 15 or 20% whose basis for calculation would be extended to all sectors and whose implementation would be, if not compulsory, at least a powerful European incentive, seems to us to be an interesting prospect.


The same term is used again later in the text:


L’assiette de ce soutien serait donc la totalité des surfaces de prairies, permanentes et temporaires, avec un paiement à l’hectare à plusieurs niveaux, afin de ne pas survaloriser les systèmes extensifs.

The basis for calculation of this support would therefore be all grassland surfaces, both permanent and temporary, with an amount paid per hectare at several levels in order not to overrate extensive systems.


Thanks for your help!