Question
i have an established lawn that is pitiful. I am contimplating tilling it under and amending the soil (mostly clay and rock), and either reseeding or sodding. I am fortunate that there are a multitude of family owned sod farms very near by, and the local utility has a yard waste recycling facility where one can purchase compost for about $11/cube yrd. I also have a large trailer in which to hall it. Do you think tilling under and resodding is the best answer?  What time of year? how do i find out how exactly to ammend the soil? I live in southwest missouri. I am also wondering how much of my 4 acres i should do at a time or just do it all? Help, please.

Answer
Hi Tom;
I think you are on the right track.
Trying to deal with that clay is jueat years and years of frustration, hard work, and not very good results.
Till it up, till in bark mulch, hunmus and peat moss.
How much you do depends on how energetic you are and how much work you can do at once ( I am old (71) and tilling up a 10X10 ft plot is too much for me.
I am in north Texas and I have hard pan clay, so this is what i did to amend it.
I put 1 part humun, 1 part peat moss and 3 parts cedar bark mulch.
The peat leeches down through the soil over years, and helps to break up that clay down below.
I wanted 8 inches of top soil, so I put those amendments on the ground, 4 incjes deep, and tilled it all up to a depth of 10 inches.
That made almost 1 part mix and 1 part existing soil.
Made loos enough soil to let water drain through, the roots to have room to srow, and got my lawn off to a good start.
Thinking more on it, My hubby may have only itlled 8 inches deep.
I know I still had a hard clay down under that, so for a couple of years,I put down about 1 or 2 inches of granulated gypsum, and let the watering wash it down through the soil.
Granulated gypsum really helps break up that clay.
2 inches down in the fall, watered in well, and disolving and going through the soil through the winter loosens up about 1 inch of clay by spring. Of course, over the years it loosen further down.
My friend lives in rolla, and I went up there a few years ago, and I was going to help her with her clay yard.
We went to a nursery to get cedar bark mulch.
The reason I like cedar is for the insect repelling properties and it takes 2 years for it to compost, where it takes 1 year for hardwood mulch to compost.The lady at the nursery was the rudest indivudual You can imagine and wouldn't answer a question for me at all.
She didn't have cedar bark mulch. She had I think it was cyprus.
Anyway, She said it was just like cedar.
I asked if it repelled insects, she said she wansn't an insect, but she didn't mind it. I asked how long it too to compost.
She said "I don't have time to stand here answering questions all day, there it is if you want it buy it."
that was the only nursery in town then.
She had some pelleted gypsum. I bought that, and bought some to take back home, because my nursery here had stopped carrying it, and I still had some area of back yard to loosen up.
The pelleted gypsum was little gray worm looking spirels and I used it. It didn't do ANYTHING!!!
The gypsum I have always used was granulated, and wah snow white.
You can just go to US Gypsum and get powdeed, but the powdered blows around so bad.
I have since read that cyprus bark is like cedar in the insect repellant property and it takes longer than hardwood bark to compost.
I would use cedar bark mulch if you can get it.
I put cedar bark mulch all over my yard and a trail of it right up at the foundation of the house, to keep termites away from my house and property.
I never get termites.
You would need at least 3 to 4 inches of amendments to till in with existing soil.
Sand would help a lot too, in place of some of the bark.
I don't know what you have to pay per yard for sand there, but here, when i did my lawn, playground sand was all you could get in 2 or 3 yard lots, and that was way more expensive then bark mulch.
You could buy a lot of earthworms, and they will work on loosening the soil.
I guess a big load of fishing worms would do well. I am not very knowledgable of worms, can't abind to look at the critters!
but earthworms will  tunnel through, and that aerates, and their droppings (castings) enriches to soil, so it loosen it up and amends it nicely, of course they take time to work., but getting 6 inches of top soil, which is what you will have after you till in the bark mulch and sand( if you use some of that) humus and peat moss, and then letting the worms work for 2 or 3 years, and you should start to have better and better drainage, and your top soil depth will increase through the years.
6 inches would tide your grass and plants over for a couple of years.
So,,,, it depends on how much work you want to do as to how much of it you do at once, and how much you want to spend on amendments for quicker results.
But Bark mulch keeps it looser while it is composting, and then adds nutrients when it does compost.Humus and peat moss add nutrients.
You could probably put 2 parts humus and 2 parts peat moss, but be careful, especially with the peat moss. You could make your soil too acid, then you would have a whole new set of problems.
Good luck.
Charlotte