Question
I live in Dutchess County NY and I'am having sod installed. My soil is clay, I would like to know: 1}The proper way to amend and prepare the soil before the sod is installed. 2}Should topsoil be added after the soil is amended,if so how many inches, screened for $18 or screened with compost for $25 is available in our area, will it make a difference to spend the extra money. 3}I have 15,000 square feet of yard, on the bags of peat moss it does not state how many square feet a bag will cover, would you know how many bags of 3.8 peat moss I will need for this area. 4}Please help me with the proper preparation for my sod installation to be successful.  

Answer
Oh how landscapers love to sell that topsoil.  I can't see the ground around your house in Dutchess County, but my guess is that your money will be much better spent on amendments than on trucking in less than perfect soil..  Since you have splurged on sod, you owe it to yourself to find out the good, the bad and the ugly things about the soil that sod is going to grow on.  Cornell Cooperative Extension (http://www.css.cornell.edu/soiltest/newindex.asp) will do a first rate analysis for you.  If ever there was a good reason to test, this is it.  Trucking in someone else's dirt won't get you any closer to the answer -- and it's probably not necessary.  Just because you have clay soil does not mean you can't grow the best looking grass in Dutchess County on it.  Just add a few things.  

What exactly -- well, we don't know what it needs, and that's what the test is for.  Once you find out, rototill them in, wait a few days for the lime to settle in, and plant the sod.  This work is critical whether you are planting grass or sod.  

You're right if you expect that peat moss is going to be needed.  It's a  perfect solution to high clay composition.  You will also want lime, and I would say a modest amount of organic matter.  The reason being, your sod is probably grown on non-organic soil, under non-organic conditions; residual toxins will inhibit the biological activity at the roots of the sod, and anything you can do to promote recovery of the soil is going to shorten the time that the grass will be stressed and vulnerable to things like fungus and insect damage.  

Since Math is not my cup of tea, I have looked to the Iowa State Extension Service (www.extension.iastate.edu -- see their release, "Sphagnum Peat Moss Improves Poor Soils") for their sage advice on quantities of peatmoss.   For general plantings, they recommend a 1-inch layer tilled into your top four inches of soil.  Iowa State calculates a 3.8-cubic foot bag of sphagnum peat -- which you understand doubles in volume once the bag is opened -- covers an estimated 90 square feet of  ground.   Depending on your clay content, you can add more or less.  Remember though that the pH for sphagnum peat is about 3.5-4.0; you will have to add extra lime to keep the final product as close to 6.5-7.0 as possible -- the ideal pH for the most commonly used turfgrasses and most certainly if your sod is Kentucky bluegrass.

Optimal results would be achieved with 175-200 3.8 cu ft bales of grower peat moss, to which you would add as much as 100-150 lbs. of pulverized or finely sieved limestone to offset the low pH of the amended soil.  Do a quick soil test to make sure you are getting a good reading on the soil pH before you sign off on the sod delivery.

The biggest mistake with sod is that people think once it's down it 's care-free and they don't pay attention until it's too late.  

Make sure the sod is cut the day it is going to be delivered and layed.  Sod can't handle a day out of the ground without suffering major damage.  It may even look fine when it's put down, but for every hour it has spent out of the ground, root fibers are drying and dieing.  The basic ground should be watered befor ethe sod is layedd, and after it is down, the sod should be watered again, thoroughly, right through, especially toward the far edges of your property, where roots are exposed.  Water your sod every single day after planting until the roots are firmly established.  Kentucky Bluegrass especially is going to need a good High Nitrogen feeding a week or so after the first mowing.  After the sod goes down, go out and buy yourself a few bags of white clover, which will help fix the Nitrogen in the soil and is a good step toward lawn health.  And remember to have them put down a balanced fertilizer to keep the lawn from turning yellow.

I take it you are probably looking at a landscaping service to take care of your beautiful new lawn.  Most professional landscapers are small businessmen who work hard on back breaking projects, but are not familiar with organic techniques.  Let's face it, do you see some sunburned guy with a truck and lawnmower loading up boxes of praying mantids and ladybugs for an IPM program for his customers, or spraying nematodes and milky spore disease to control wiggly little grubs under the soil that will emerge as Japanese Beetles later?  No way, Jose.   

But some of the most well known crabgrass killers and bug sprays are incredibly toxic.  Why do you suppose little signs have to be put up to alert neighbors to the recent use of several of these products.    On Long Island, where I live, the "breast cancer epidemic" that has gotten so much publicity in the past 10 years is actually concentrated in small toward the East End, where potato farms were developed  -- and decades later, residents are suffering from long term exposure to all the chemicals the farmers once used.  

Across the country, children who live in homes that use pesticides on the lawn have almost a 7 times greater rate of leukemia.  People who live near golf courses, groundskeepers at golf clubs, and golfers themselves suffer from a long list of health problems related to landscapers' toxic chemicals, the most common being non-Hodgkin's lymphoma.  Tell your landscaper you absolutely forbid him to use any of those WMDs around YOUR house.  Instead, insist he put down a product like GardensAlive's "WithOut Weeds" (www.gardensalive.com). to weed and feed that gorgeous swathe of green around your house.  It's so nice to walk barefoot in the grass.  

Keep me posted if you can on how things are going with your sod project.