According to wiki diatomaceous earth is used as a insecticide. This is their description.
Pest control
Diatomite is used as an
insecticide, due to its abrasive and physico-
sorptive properties.
[8] The fine powder absorbs
lipids from the waxy outer layer of insects'
exoskeletons, causing them to dehydrate.
[9] Arthropods die as a result of the water pressure deficiency, based on
Fick's law of diffusion. This also works against
gastropods and is commonly employed in gardening to defeat
slugs. However, since slugs inhabit humid environments, efficacy is very low. It is sometimes mixed with an attractant or other additives to increase its effectiveness. Medical-grade diatomite is sometimes used to
de-worm both animals and humans, with questionable efficacy.
[10][11] It is commonly used in lieu of
boric acid, and can be used to help control and possibly eliminate
bed bug,
house dust mite,
cockroach,
ant and
flea infestations.
[12][13] This material has wide application for insect control in grain storage.
[14]
In order to be effective as an insecticide, diatomaceous earth must be
uncalcinated (i.e., it must not be heat-treated prior to application)
[15] and have a mean particle size below about 12 µm (i.e., food-grade— see below).
Although considered to be relatively low-risk, pesticides containing diatomaceous earth are not exempt from regulation in the United States under the
Federal Insecticide, Fungicide, and Rodenticide Act and must be registered with the
Environmental Protection Agency.
[16]
In order for any compost to work, you need browns, greens, air and water. Bugs are also a big part of this. If you are using DE, IMHO, you are killing off all the live bugs that are needed to make the deep liter method work, either in the coop or in the run.
I have a large side yard that my chickens are in. Its about 40x120. The chickens have the area around the coop down to bare hard ground, and have grass in the other areas. So in front of my coop, I placed several large bags of mulched grass and leaves. 5 large construction bags all in a pile. I threw some sunflower seeds down and the chickens went to town (this is the air and mixing of compost) . This area is where I feed them their greens, fruits and other veggies. What doesn't get eaten, will get scratched down and added to the heap. Composting also need moisture. So when I notice its all dry, I will water it slightly, put more seed down and let the chickens do their thing. When it rains a lot, I have noticed that the ground is actually absorbing the rain now instead of it running on top of the ground. I no longer have puddles. The ground below is starting to be broke up and is softer, yesterday I saw under the mulch/compost some green trying to grow again. Of course the chickens ate it up but quick. So I do know that my ground is becoming more fertile, softer so grass can grow again and with all that more bug activity. Which also is good for them. They have the mulch spread probably 15' all the way around the coop. They add nitrogen to it daily as well as turning it daily. I also am continuing to add brown to it as needed. As well as some green and watering it. And of course they add green to it daily.
At the far end of the yard I also have a 3 bin compost system. Made of wood, the chickens are forever playing around in it. One section is completely closed off to them, as that's where I put all my foods/plants I don't want them to get. The other two are piles that are further along in the composting and I have no problem with them getting in there. Once a week I go and rake it all back into the bin, water it, close it off for a day or two, cover it, then open it up and let the have at it. I do put a small amount of sunflower seed or scratch down to get them started. But once they start they can be out there all day long.
Do I have flies? Yes, any outdoor area with poop added daily is going to have flies imho. However, I don't have a ton of them. I also don't have the chicken poop smell in my yard. If you came to my house, other than seeing the chickens you would not know I had them, you can't smell them. I smell the cows across the road on occasion when the wind blows in the right direction. But I don't have an odor from the chicken yard or coop.
I also do dlm in the coop. I have it build up to about 7" atm. It should be about 9 come winter time. Once a week I take the pitch fork and give it a small turn about in the coop, I will also throw some seed or scratch down inside and the chickens will turn it for me. I have 2 fly strips in the coop, one has a lot of flies, the other has a few. I put them up when the coop was completed (we are new to chickens, and had to start from scratch) But I have not had to add anymore fly strips. I just don't get that many flies now that the dlm is set up in the coop and yard. I have 14 laying pullets and 2 turkeys. The turkeys roost outside at night and the chickens are in the coop. They keep it fairly clean. I also have recently added a poop tray. I give it a clean every two days and have not noticed an increase in the amount of flies. The poop then gets added to my compost.
As far and plants go, good luck! The chickens will destroy any new plants. I have a garden in the side yard as well. It is enclosed with chicken wire. Occasionally I will have a chicken fly into it or dig under it. They are decent for bug control as long as I'm out there with them. BUT when I'm not, I lose plants. They have made a mess of my potatoes which I have mulched with straw. They love the straw. They destroyed my onions and carrots. They walk through my watermelon like they own it. and they eat all the starts of my cucumbers and zucchinis. After my fall crops are done, I am planting a cover crop, which once about 6" tall I will open my garden up to them. They can eat and scratch all they want. I'm just hoping they don't ruin it all before it has a chance to do what it is supposed to do for the garden lol.
Deb