Mulch grass with grass cut by a scythe - How much cut grass is needed?

Hey all,

I have a bunch of old pasture that is covered with a mix of grasses that get chest high, 2 types of vetch, birds foot trefoil, and a mix of other non-woody plants. A lot of the grass grows in large bunches that are a pain to cut through. I want to convert this old pasture to hedgerows, food forests, gardens, etc. This will take a while but my first goal is to start on some hedgerows along one of the edges of my property and around my fenced backyard about 6 feet out from that fence. Right now all those areas are covered in the grasses with some blackberries in a few spots.

My question for you all is how much cut grass would it take to smother the existing pasture vegetation?

I'm planning on cutting sections of my old pasture with my scythe which means I will have a large amount of cut grass. I can fairly easily gather this cut material up and place it over the areas where I want to do my hedgerows. But I'm not sure how thick to initially add the cut grass.

Is a foot enough? Or should it be 2 feet thick? Or less?

For both those measurements I'm talking about freshly placed cut grass that is still green and hasn't dried up or compressed down.

The cut material will also be fairly long and thick since I'm cutting with a scythe.

Any thoughts / advice would be really helpful. The hedgerows will be between 6 and 10 feet wide and I'm looking at approximately 100 feet in length for one of the hedgerows, 90 feet for another, and 60 feet for another. But I don't need to prep all of these this year but these 3 hedgerows are the first I'm going to be focusing on.

I really like the idea of using the material I'm going to be cutting anyways since it would keep me from needing to bring in extra material. I've used fall leaves and wood chips in this way before but I've never tried to kill existing grass just by using cut grass. But it would make my life much easier if I can get this worked out--I just don't want to move a bunch of cut grass and then realize I didn't move enough to kill the existing grass.

Before I forget... one last question. Is it best to cut the existing grass before placing the cut grass on top of it or should I just flatten the existing grass first and call it good?

Thanks all!

Following.  My guess is 10 to one m2 ratio. I'd cut the grass first and use any spare carton.

All I can add is that long scythe cut grass won't smother grass as easily as mower mulched grass because it won't form that crusty mat that mower grass does. I think you will want to do a bit of compaction (even just stomping down the heaps) and try to get an 18-24" layer of manually compacted grass, sort of aiming to simulate baled straw?

Looking forward to your experiment though

https://www.youtube.com/watch?v=ziYl8e5K8o4
This guy uses hay to mulch and prepare a market garden in maine.
Edited for spelling.

Some people twist the cut hay into a "sausage" to lay it around hungry crops. This has the advantage that the ring can be lifted to check for slugs.