Can you post the actual lab results? Morpheus will give you a detailed report on your results. Just do what he recommends and you'll have a great lawn!

Although I can tell you off the top of my head that you should NEVER apply 20 pounds of sulfur all at once. Or probably at all, surface applied sulfur isn't very effective. There may be other methods, but what I can advise will depend on the quality of the soil test.

Where do you live? I would guess somewhere in Texas, but you seem to be in zone 4?
What kind of grass are you growing? And I'm also guessing that the grass looks pretty good, but then you got the soil test for a good reason, I'm sure.

I'm no expert but with that much calcium, you can apply pure sulfuric acid from now on and never get your pH right. Do you have a limestone quarry nearby? I have one two blocks over and about a dozen in a 20 mile circle. My soil is all limestone rubble on a 900 foot base of solid limestone. Adding sulfur is futile.

I'm in Nebraska...as far as grass goes, I'm not even sure. I just overseeded with kentucky bluegrass and creeping red fescue. We had it aerated last week as well. We have several thin areas and some areas where grass is barely growing. We've lived in the house for 8 years and the lawn was in bad shape when we got there, but it slowly got better and then all of a sudden, the backyard isn't where I"d like it.

I know of no quarry's anywhere around me. The closest one I can think of is 25 miles away. I had a thread awhile ago asking for people's help with the backyard. People had opinions, but basically wanted soil test results. So, I went ahead with that, and just got them back yesterday.

Thanks morpheus...I greatly appreciate it. Would you recommend that I continue to core aerate in the spring/fall and overseed? I have started to mulch mow instead of bagging and have paid attention to watering pretty closely. What are your thoughts on the bumpiness of the lawn? It doesn't appear to be worm, mole, etc related...just bumpy. I've always wondered about rolling but that seems to have very mixed opinions on it. Also, what are your recommendations to feeding organically that you mentioned?

You can core aerate if you want to, or shift over to the shampoo method. The latter will last longer, go deeper, and does the entire lawn instead of a 1% core profile.

Overseeding is fine if you want to, although I think that balancing the phosphorus means you won't have to overseed quite so much.

Sometimes soils that weren't flattened with a box blade are bumpy, or spotty grass growth can generate a bumpy feel to an otherwise flat soil. For now, I'd say ride it and re-evaluate it in a year or so when the soil is a little more balanced.

Organic feeding this year is a nice thing, but I've got enough nitrogen flowing in from the starter that it's not absolutely required. Still, it IS a nice thing. :-) For you, cottonseed meal will be the best feed, although any inexpensive organic can be used if you can get your hands on it. Just keep in mind that most other things than cottonseed, soy, or Milorganite tend to be weaker feedings. All will help your soil out.

I'd need to know what you can get your hands on to make any recommendations here. If you have a local grain mill (don't laugh, I'm fortunate enough to have one!), farmer's co-op, Tractor Supply, or animal feed store, you have a good source of organics!

I can get to a tractor supply, co-op etc pretty easily. We have a bomgaars close as well. I know I've seen milorganite in the bomgaars but haven't really looked anywhere either. I'll have to look into the shampoo method rather than aerating.

Shampoo is a poor man's surfactant. If you were a professional sports team or a golf course you would use Cascade Plus, a commercial surfactant concentrated for very large acreage. Spray 3 ounces of any clear shampoo per 1,000 square feet and follow up with at least 1/2 inch of water. Repeat every 2-3 weeks as needed until you notice the soil getting very soft following a rain. You can test the soil 'hardness' by sticking a screwdriver into it. See how deep it goes before you start with the shampoo and then a week or 2 later. It should become very soft when moist and then get hard again when it dries out. I applied twice in 2011 and it's still soft when it rains. Core aeration never (ever) worked like the shampoo does.

http://www.amazon.com/Potassium-Sulfate-Potash-Organic-Pound/dp/B004JD6MGK

Would this work for potassium sulfate?

It would, but that price is absolutely hideous. Call a local garden shop or landscape place and see if they can order you a bag (or have it in stock).

Google 'Crop Production Services' and locate someone near by, they are for farmers and often supply smaller feed/seed places. In farmier areas they might ONLY work with farmers, but often times they will work with regular folk as well. 50lb bag normally runs around $35

Here ya go: http://www.cpsagu.com/map/Default.aspx