How would you characterize your soil? Would you call it clay, loamy, or sandy? Is it hard to dig in? Does it seem to hold water?

Where do you live?

I would say my soil is somewhat sandy but also hard to dig. Once you get it chopped up it crumbles into very fine particles.

I am in zone 6/7 in NJ.

What amendments should I make from my test results?

Ah, New Jersey soils. Gotta love them. Or not...

Exchange Capacity 5-ish: Sandy, which is pretty typical for NJ. Raise your organic matter levels if you can to slowly and slightly lift this, and increase water retention in your soil.

pH 5.0: Very low, borderline what I just call "awful." We'll fix this under calcium, magnesium, and (a little) potassium below.

Organic Matter 3.1%: In the Fair range, and not a problem, but given your low EC I'd raise this. Always mulch mow, mow all your fall leaves, steal neighbors' leaves, and so on. Toss your morning coffee grounds on the lawn. Whatever source you can find that's very cheap or free is great.

Sulfur 14: Normal.

Phosphorus 536 (354 adjusted for sample depth): High, but not at all extreme--the target would be 200 for the adjusted. This won't be a problem, but don't use starter fertilizer or other high phosphorus fertilizers. You don't have to avoid all P sources, though, and minor ones are certainly not a problem.

Calcium 33%: Very low, which is setting off your low pH of 5.0. My target here, for a low EC soil, would be around 70%. We use Encap, Mag-I-Cal, or Pennington Fast Lime to adjust this as other limes contain elements I don't want to add (at least not in this way), or work too slowly. Recommendations below.

Magnesium 9.9%: Normally, I'd call this close enough and move on, but with your lower pH I wouldn't mind boosting it a little bit (your very low EC also influences this decision and moves the optimal band closer to 12-13%). I am not at all concerned that this will tighten your soil, it's sand already. We use Epsom salt from your grocery or local drug store to fix this, and the store brand is fine. Scented or unscented, it doesn't matter. Recommendations below.

Potassium 2.8%: On paper, it looks OK because there's no calcium in the soil to kick the potassium. This will drop--fast--when you lime, and the soil shows a significant shortage. We use potassium sulfate to fix this, which you can get from landscape or garden stores, or they'll order it for you. It's also available online.

Minor Elements:

Boron 0.26: While not the most important element, I'll always work to move your lawn into the most optimal range on everything. Me? I'd fix this. We use Milorganite as a carrier and 20 Mule Team Borax as the boron source. You can purchase 20 Mules at the grocery store in the laundry section. In a wheelbarrow or the like, dump the Milo. Spraying very, very lightly with water (I use a spray bottle like the kind people use to damp their clothes when they iron) will help the boron stick. Add the recommended amount of 20 Mule Team Borax and stir, spraying occasionally to get the stuff to stick to the Milo. Then apply over the recommended area. So if going for bag rate Milorganite (1 bag per 2,500 square feet), you'd add 10 tablespoons of 20 Mule Team Borax.

Recommendations:

October 1: Feed the lawn normally with a high nitrogen fertilizer.

October 15: Apply 9 pounds per thousand square feet of Encap, Mag-I-Cal, or Pennington Fast Lime.

November 1: Apply 2 pounds per thousand square feet of Epsom salt.

Recommendations, 2017:

April 1: Apply 3 pounds per thousand square feet of potassium sulfate.

April 15: Apply 9 pounds per thousand square feet of Encap, Mag-I-Cal, or Pennington Fast Lime.

May 1: Apply 4 tablespoons of 20 Mule Team Borax in Milorganite carrier.

September 1: Apply 3 pounds per thousand square feet of potassium sulfate.

Thank you, Morph!

Our Jersey soils aren't too far from yours in PA.

Since I am overseeding this week, should I make any of these amendments now or right after seeding?

I'm also seeding in a little white "microclover" , if that makes a difference.

morph is there anything he can use besides potassium sulfate? I'm thinking the sulfate would further unbalance the pH.

Potassium sulfate, a one molar solution, has a pH of 6 (actually higher than his current pH). He won't be using it anywhere near 1 molar, so the pH will be in the 6.8 range if mixed with pH 7.0 water. Which won't happen, our rainfall is in the 5 range. Regardless, no worries there.

Over the medium term, the sulfates wash out, the potassium binds, and the pH result is a slight rise.

jb989: With seeding, let's put off the calcium until November first, and the Epsom salt until November 15th. I have zero concern that we're going to get an early ground freeze this year...I'll be happy if we get frost by Christmas. :-)

I'm thinking the sulfate would further unbalance the pH.

The effect of sulfate is nil. Sulfur acidifies, yes, sulfate, not.

>H = acidity/lower pH.

Acidifying amendments like aluminum sulfate and iron sulfate lower pH not because of the sulfate, but because of the chemical reaction of the aluminum or the iron with water to free up hydrogen.

With sulfur (elemental sulfur or the sulfur coating on fertilizers) it takes microbiological activity to use the sulfur to create sulfuric acid and acidify the soil by the eventual freeing up of hydrogen. It takes about 2lbs of sulfur to lower the pH of 1000sq ft of soil to a depth of 6" by 0.1 pH.

N fertilizers have an acidifying affect due to nitrification (biological again) which releases hydrogen.

In the case of ammonium sulfate, although sulfuric acid is created because of the presence of sulfate, the hydrogen release (lowering of soil pH) is due to nitrification of the ammonium. The sulfuric acid is just a bi-product wash in regards to acidifying the soil and does not create any additional acidity that was not already created through nitrification.

Thank you, but this discussion is way over my head. :)

I am seeding this week. Do I need to put anything down before seeding?

Sorry about the cross talk. It was to clarify the issue regarding sulfate with dchall.

Bottom line: potassium sulfate will not affect your pH. Amend away.

You don't need to apply anything before seeding, but a half rate of NK fertilizer with no P wouldn't hurt. One with slow release N (poly coated, not sulfur coated) would be ideal.

You're fine. Although it has a low pH, the dry mass is also very low, so it dilutes in the soil and has very little effect. Effectively, you won't notice it at all.

I also used peat moss and I'm a huge fan of it for germination top dressing--it's light, pretty close to sterile, very fibrous, and cheap.