The carrying capacity of a location has so many variables as to make a prediction of dependable yield per colony almost impossible. About the best one can do is cruise the area for a couple of miles radius taking careful note of established forage and water availability. This will include known nectar sources for the area and their seasonal abundance. Where I am (rural eastern WA) spring starts in late April with several highly productive tree blooms, Vine Maple, Black Hawthorne, Black Locust, in that order. Next is early summer Purple Vetch, Blackberry, Canada Thistle and the agricultural crop Canola. Late summer is dominated by Yellow Starthistle which is usually 1/2 to 2/3 of my total crop. 

Back to the variables. Once a promising location is established that gives the bees access to all the above the beekeeper is at the mercy of seasonal variation of  precipitation and temperature. Also many tree species have a habit of prolific bloom one year fallowed by a light bloom the next independent of the above conditions. I have locations that I have used for decades and can give a pretty good estimate of a 24 colony yield on a 5 year average. Within that the variation can be huge. The last two years are a perfect example. This past summer was a dream come true. Far above average spring moisture and everything else in good co-ordination for a 225# average. The yards could well have carried twice the colony count. The previous year was a disaster. A prevailing severe drought, the infamous northwest heat dome, 117 F at its worst, for a yield of 30# and it would not have made much difference if there were only one colony per yard. Same location different year.  

So finding the carrying capacity of any location can only be established by trial and error and seeing how many colonys it will support before the per colony average starts to fall over a number of years. 

Then of course the competition. I am talking a 2 mile radius without other managed yards. I have lost a good number of what for me were great locations only to find a new yard of 200 show up with the only goal to reduce feeding cost for pollination outfits. Kind of lets the sand out of a guy. 

Paul 

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