Weed grass on my hugel

I built a hugel last summer and have been having a hard time with it because the chickens think it is great fun to kick the soil off until they come to the wood layer.  For some reason they have been staying in the coop, so I thought I would put the soil back on again, and put something on it to deter the chickens.  The problem is all over the hugel is a grass like weed.  Probably Johnson grass.  It is way too much to pull by hand.  Do I use a hoe to try to remove it, or spray it with vinegar and kill it first, or should I put the soil on it with a thick layer of wood chips on it to try to smother it?   I guess I'm asking because I don't  think any of these solutions will work, and I dread having my hugel covered with weeds.  Any ideas?

I don't know that I would do the wood chips. You already have a lot of wood in there. Try hay.

I'm really lazy so I won't hoe or pull by hand. I'd just put hay on it and pray.

In my area johnson grass invades when the surface is disturbed (like when a hugel is built). It seems to go away when things return to normal. It is slowing erosion as well as chickens, plus the size of johnson grass is a huge amount of mulch as a chop and drop. I may consider it a good thing.

My area is rural and my hugel is huge, so i can be patient and let things go thru their cycles. In my head i also realize that productivity will take a couple of years, so i am not concerned with the now of it.

Someone in an urban setting who has limited growing area may have different views. Especially if this is their main planting area or aesthetics is a factor.