The terms of use for the software define a farm as:
“A Farm Account represents a notional farming operation to be modelled in Overseer…
Each Farm Account must be used to model only a single farming operation. This may include the modelling of adjacent or additional land to the extent that it is relevant to nutrient and/or greenhouse gas modelling for that farming operation.”
In practise, this means that if multiple properties or dis-aggregated blocks are part of the same farm system, then they can be included in a single farm account.
Equally, if the seperate properties are run individually, with no (or little) crossover, then those properties should have a farm account each.
For example this means that if a farm business is made up of a breeding farm for sheep and beef in the hills, and then a finishing block, about 40km away, on the flats near the coast with stock moving between the two locations. That is one single operation, with stock moving between them and one Overseer account even though it is 2 farm properties.
In contrast, if a business has a dairy farm in one location and a Beef and outdoor pig farm in another; the two farms are entirely separate, so they should have an Overseer account each. (this would remain the case even if the beef farm was used for rearing young dairy stock or over-wintering dairy cattle).