"Can someone explain what happens to the buried "green" materials?"

Yes. Here's what happens:
During the night, a critter digs them up and in the morning you find them partially eaten and scattered around the yard.

Just kidding. That doesn't necessarily need to happen to you (I live in the country, so that's what happened to my first attempt at "sheet composting," as it were.)

I'm sure someone with more knowledge will log on here and give you a real answer. :)

I've done this for over 30 years and call it 'feeding the worms' as once the decomposition process starts the worms are all over it. I've found there is nothing discernable left after a few weeks except for the slower decomposing stuff such as onion skins, broccoli ends, peach and avocado pits.

I've only ever had one 'critter' dig up one of the sites and that was an old bear who was looking for the worms. Even tho I live on a large acreage in a rural area I don't have the same critters as some other places do. No skunks or raccoons here. I dig the hole a shovel depth, cover well, and tamp down so there may not be much odor.

My perennials have grown so big there are no spaces between them anymore so I'm again doing a pile until I thin out the perennials. Worm castings are the best fertilizer.

Dig a trench behind or between your perennials, or in a vegetable garden ... as each day's kitchen scraps are dumped, cover that part of the trench. A layer of scraps 6 or so inches deep, covered with dirt, will be gone by next spring.

It doesn't really turn to "compost" ... it just vanishes, decomposed by the soil microorganisms and insects.

My childhood neighbor regularly did trench composting between the rows of her vegetables ... the next year she shifted the rows to be on top of the trench and the new trench was in the old row space.

The material you bury in soil is digested by bacteria and fungi that live in the soil, the Soil Food Web. Soil does have air in it. or at least soil that is not compacted. A good soil will consist of about 45 percent mineral (the stuff that makes a soil sand, silt, or clay), about 5 percent organic matter, about 25 percent moisture, and about 25 percent air.

Thanks to all for your suggestions and explanations. Sounds as if those kitchen scraps attract the worms who, in turn, benefit the soil. From your comments, I can use 'burying the scraps' to prepare future perennial beds. The perennials in my current beds are mostly planted 3 or so feet apart and, when mature, the blooms and leaves will come close to bridging the gap and nearly touch each other. If I'm understanding you correctly, burying the scraps between the plants will "feed the worms", whose presence benefit the nearby soil (and the plants' roots). Right? Wrong?
Knock on wood, I've rarely had critter problems. Dreamed once that I had signed a peace treaty with them ... but I've been known to dream a lot of crazy things.
Best to everyone!

In heavy clay or dirt it is the fastest and best way to amend soil. Microbes and also bugs come in and process it very quickly if the ground is ketp moist. I dig in a spot and continue to dig in around it widening the area where I want the new bed.

That area is now my best soil in the entire garden. The sun tears up organic matter extremely quickly. Burying it in ground protects it in Oklahoma sun.

I use this method as well as regular composting. Dug in soil in my yard creates a silt. Compost material helps lighten the soil for plants that don't like heavy soil. I plant heavy feeders in the dug-in compost areas.

This post was edited by ChickenCoupe on Thu, Jun 26, 14 at 13:34

concur with lucky gal. You have to pay your worms if you want to get work done, and kitchen scraps are best. of note, all nitrogen is re-used in well buried kitchen scraps, unlike composting that wastes half of it.

By putting organic matter in the soil you feed not just the earthworms but the other members of the Soil Food Web. Some people may think that earthworms are the only inhabitants of soil because that is what they can see and many of the others are too small for the human eye to see. However, there are millions of wee critters in soil digesting the organic matter and helping feed any plants growing in that soil.

Again, thanks to all who responded.
While reading your posts, I began thinking about the term "kitchen scraps" and that it may mean different things to different people. I've been told that, with respect to a compost pile, meat and oils should be avoided So I am assuming they should not be dug into the soil, even if you don't have a critter problem. True?
And what about vegetables that have been cooked? Sometimes you just can't get the family to finish off those leftover green beans, mashed potatoes, spaghetti, tuna salad, etc.
Would you include cooked foods in your "kitchen scraps"? Or do you restrict it to uncooked foods?

Terratoma

Absolutely. Anything. But I cannot verify regarding meat items. My dog gets them in home cooked meals. I do put raw and cooked eggs and egg shells in ground as well as old tuna or tuna salad scraps. Fish is most excellent for soils.

The worms and microbes love it all. Just dig, dump and bury.

I've been told that, with respect to a compost pile, meat and oils should be avoided So I am assuming they should not be dug into the soil, even if you don't have a critter problem.

Not true ... think of the tale of Squanto and the corn and the fish. I have composted bunnies, pigeons and various meat with no problems. The State of Montana composts roadkilled elk

Large quantities (more than a couple of pounds of meat or a cup or two of oil) have to be mixed well into a layer, because the meat will stink and the oil go rancid, but by the time the bin gets broken down there is no trace of the oil or meat ... or tree rat.

Would you include cooked foods in your "kitchen scraps"? Or do you restrict it to uncooked foods? All leftovers, fuzzy things from the frig, etc go into the compost.