Wow, thank you to everybody for the thoughtful replies, there's nothing like having advice from direct experience! Its been extremely helpful to read these replies.
To answer some questions, first off to Dr. Redhawk:
- Yes, I definitely want to start with 50 and 100' beds this season. I should've been more clear in my original post. My thoughts were to plant locust on the edge of plot, to help with Ni affixation and also possible living/extra fence to go alongside electric deer fence on the perimeter. The suckering would perhaps be a benefit; we are off-grid and use wood stove heat so good firewood is always appreciated. Just behind this edge is 40 yo white spruce (can be seen in 2nd photo) on one side, and 60-70 yo white pine on the other. These trees wont be coming down for a few years, so I was thinking the BL could be started to help in the interim. I factored in the edge shade as it grows, but perhaps I was being too conservative as to what BL will put out. The intention for this particular plot is high density market garden beds, so every inch will count.
Another key point is that BL is nowhere to be found on my 200 acre plot, nor is it prevalent in my area. It does grow in certain places in my province, but not in abundance around here. However, red alder does. Great points, Daron. I do have various alders throughout the property, and it's evident what a terrific benefit they are to the soil and surrounding trees.
I think after reading these replies that I will stick to cover crops for the plot (which I was planning on doing this spring) alongside continued comfrey planting. The nice thing about this land is I have a few spots to experiment, so I would still like to see what a section of BL can do in regards to fencepost and firewood production. Of course any Ni spinoff is always great. This area will be offsite, approx 750m down the road where I think it will be suitable and relatively manageable.
Thanks again folks!!!