The only real way to find out is to establish an apiary and increase the numbers every year until you notice a decrease in production. And then you won't really know, because it could have been due to the weather.
Originally Posted by Docking
I have apiaries of differing sizes, depending on whether the hives are on warehouse pallets or 4-way pallets and thenaccording to what number of colonies I wish to have to work before moving on to the next yard. That's when I take my breaks.
I know other beekeepers, in this area, who have 60 or 80 colonies in each yard. I also know beekeepers who complain about other beekeepers dropping those big yards right down on top of them. They think that that is the cause of their poor production and then later in the year they brag about how much honey they got off of that same yard. I theorize that if the nectar is there we'll all get it and if it isn't we wont.
As far as closeness of yards is concerned, I'd be more concerned about disease transfer. But that's just me.
In some states, the Dakotas I believe, apiary distances are regulated.
Squeak Creek Apiaries