I agree with the part about using something different for a top dress if thats what you need... probably better to grow a companion crop instead ... pretty sure that's what the farmers are doing these days instead of tilling the soil. New plants grow, shade the companion crops, the companion crops die back and fertilize the soil and help retain moisture.
I'm not aware of any "professionals" or horticulturalists that advocate wood chips as a top dress in a container much less say an outdoor garden. Straw.... yes, wood chips not so much. I've seen this work at N sequestration first hand... (not in my gardens) but neighbors that maybe listened to someone advocating some sort of wood chip silliness. I've also seen how long a pile of wood chips (not mixed into soil) takes to break down and compost. It's takes 5-7 YEARS.
Lets think about that and a container.... those 2 don't go together. What are we going to do when we need to amend the soil in the container? What are we going to do when we need new soil? Both of those scenarios are bound to be needed before the wood chips are composted. Now dump the container with the wood chips out now we have an issue with the leftover soil with wood chips... I can't compost it because the wood chips take several years to break down. I could compost it then screen all the wood chips out...meh.
whats up man, I've been gone for a bit, don't remember you from before...
you seem to be a good addition to the organic area my man, your advice is well thought out, and well written, It's always a welcome sight to see advice that's accurate on this forum.
Oh, and not that it matters much, but I can get wood chips to melt in about 6 months or so, if you layer them right and turn the pile right, they disappear pretty quick, but on their own and not being turned or layered with high nitrogen inputs? yea that will def take forever to break down.
heres a lil link on some more info for anyone interested.
http://extension.oregonstate.edu/question-of-the-week/wood-chips-mulch
as to the nitrogen being sequestered...
with a carbon to nitrogen ratio of nearly 400 to one, i can see your concern, and if it was sawdust or finer particulates I would be worried too, but on top of the soil it simply doesn't have enough contact with the soil to sequester enough nitrogen to make much of a difference, not to mention that even if it did, the fact that adding nitrogen to plants is the easiest of any nutrients wouldn't really make me concerned.
rice hulls and biochar do the same things too, only not as bad.
I do use tiny chunks of cardboard in my summer soils (to keep the redworms from dying off in the 110 deg weather) and those have a ratio of like 325 to 350 to one, but I don't use a lot of that in the soil, maybe 5% at most.
That all being said I don't really use wood chips for much in my plants, if I need anything like that I just use rotted tree log chunks that are well beyond composting, and also act like lil water sponges to keep the soil moist.
also they add BIMs, and are nice little condominiums for the microbes as well.