Indianapolis, your soil is indeed very alkaline and I'm wondering what the average reading --pH wise, what it is on average across the State.
Some areas of the U.S. have distinctiveness about their soils due to natural occurrences that make up a large part of their soils.
For instance, Massachusetts is highly acidic...and they must use caution when applying so much nitrogenous fertilizer.

Perhaps Indiana has particular natural soil that leans to being alkaline and therefore, how much nitrogen fertilizer you give it may be underfeeding it. Your state extension service might provide you with such information.
I did a Google search asking the question but was unable to find definitive statements by any authorized agency.

Your pH is indeed way up there isn't it so you can safely use pretty well as much nitrogen based fertilizer as your ground can safely absorb.

As far as how much....that's easy. According to how the test station has advised you to use a certain ratio of nitrogen/phosphurus/potassium.....just divide the first number...the nitrogen...into 100.
Thus on your front lawn...20/10/10...100 divided by 20 =
5 lbs per 1000 square feet.
On the back lawn....12/12/12....would require 8 lbs per 1000 square feet.

Thus for the 3200 sqare feet of your front lawn....would require approximately 3.2 X 5 ....approximately 16 lbs over the area.
The backyard would take 8.8 X 8 ...so approximately 70 lbs over the area.

I don't know why they chose to advise about a different ratio of N.P.K....but whatever
If you were to use the same fertilizer for the entire back and front areas, the 20/10/10....you would use
16 lbs for the front and 45 lbs for the back.

You can just use the bag's weight as a guide to how much of it should be put into your spreader.
Generally fertilizer bags come in many sizes but 50 lbs is about average. This then would suggest you use about a bag and a half over the whole area.

If your lawns are particularly dry....we haven't had near the April showers that we normally get....maybe Indiana has had the same ----but if they are dry, then you might give a thought to watering the areas after application.
This would send the granules down to the soil for quicker action.

Thanks jeannie

But I get difference quantities, if I use these online calculators (both give same quantity, but different than yours)

http://www.math.umn.edu/~white/personal/fertcalc.html

http://www.tulsamastergardeners.org/blackbox/fertcalc.htm

I don't know what is correct. 16lbs or 64 lbs for front

Why in the name of Odin are they recommending balanced fertilizers and starter fertilizer?

Maybe somebody out there can suggest an answer to that question, but with those tests I wouldn't be adding any phosphorous and precious little potassium, except in the back where a bit of P would come in handy.

I'd also think you'd wish to get those pH readings down toward 7.0 or a bit under, which would mean adding sulphur. However, they don't suggest that.

Consequently, I'm sure I must be missing something. I just can't see it.

Hi morpheuspa

Since the sod in the front has thinned out. I asked the lab to give me two analysis. One for lawn maintenance and one for lawn establishment.

I never applied lime. I guess the soil ph is high by nature.

Have you looked at my online calculator links? Are my calculations ok? Are the amounts excessive?

Thanks! I appreciate your time.

Ah, OK, I thought perhaps I have having a bit of a psychotic break or something.

Your calculation breaks down to well over 3 lbs of nitrogen (back, 4 in the front) per thousand square feet.

For any synthetic (numbers like 20-10-10 will be synthetics), that's way, way, way too high. You run a very severe risk of burning the lawn and killing it off, even with the alkaline soil. I feed organically and won't exceed 1.5 lbs of nitrogen at one application--and organics aren't risky in that department.

Burning is caused by an excess of salts in the lawn, and synthetics are very high in salt. That forces your lawn to reverse water out of the roots and into the soil (reverse osmosis, in other words), which renders it bone dry and kills it.

Even if you got away with it, most of that nitrogen is either going to gas off the lawn, wash away into the rivers, or go into really excessive top growth. You don't want that as all three are a waste.

One suggestion is to go organic, which has no salt, will help moderate your pH at the same time, and improves the soil--plus gets the N-P-K monkey off your back a bit. Oh, it also feeds gradually over time instead of one spike and then nothing. There's an entire forum about this (Organic Lawn Care) if you're interested. 'Nuff said.

If you'd rather go synthetic, no more than 1 pound of actual nitrogen should be applied at one time (there are exceptions for warm season grasses, but you don't have those in Indianapolis anyway).

Note, I wouldn't normally break things this way, but with an overseed coming up, I'm modifying things a bit. Others will have differing opinions and their timing isn't wrong, just different.

I'm assuming you can get a fertilizer around 25-5-5 (about that of Turf Builder, Turf Builder plus Iron, and a thousand other off-name brands) for the below. There's nothing wrong with bargain fertilizer, and Vigoro does the same job somewhat cheaper. Store brand is usually one of the large companies and does the same job MUCH cheaper.

If you get something different, the equations are:

Take square footage in thousands (so your back yard is really 9 as I don't bother with minor decimal points, and the front is 3). Take the values from the bag as a decimal (0.25, 0.05, and 0.05).

Take 1/bag value and then multiply by the square footage. That's the number of pounds per thousand square feet to apply to get 1 pound of a given nutrient. Generally I use nitrogen because that's the highest number on the bag.

So 1/0.25 * 3 = 12 lbs of 25-5-5 in the front, or 4 lbs per thousand square feet of your fertilizer.

That's exactly 1 lb per thousand of nitrogen. You can then calculate the other two values by: 4*0.05 = 0.20. So you're adding 0.20 lbs of phosphorous and 0.20 of potassium.

Out back, 1/0.25 * 9 = 36 lbs, with the same pounds per square foot of everything going down.

Or a grand total of 48 lbs over the whole lawn.

OK, the math is done, we now return you to your normal schedule.

In this one particular instance, you're planning on overseeding so I'm hearing that you have a weak lawn. Consequently, I'm going really high on this schedule. If you don't have a lot of bluegrass this schedule's a bit aggressive and I noted that below

May 15: Apply 4 lbs per thousand square feet
August 15: Use Starter Fertilizer instead to prepare for your overseeding (this isn't critical and you can use the other stuff instead if you like)
September 15: Apply 4 lbs per thousand (skip if you don't have bluegrass)
October 15: Same
November 15: Apply either 4/thousand or use Winterizer at the correct rate (which you'll calculate)

That's 5 lbs N for the year (very high), 1 lb phosphorus (more than enough) and 1 lb potassium (a bit trim, but still OK with your readings). Normally I'd never cut the September feed, but with seeding the August one will have to do. If you skip seeding and don't have bluegrass, skip August instead.

Is that enough variables for you? ;-) If it's too confusing, let me know what type of grass you have and I'll take another shot at it.

That soil test looks like something from my neck of the woods. I'm also a bit surprised at some of the recommendations. Sulfur might help bring the pH down, and they didn't recommend that. Although that may be because it's not always practical to try to lower pH over an entire lawn. With pH that high, I'm not too sure spreading iron will help much. The iron won't do any good if it gets bound and can't be used. A foliar spray might work, but only do that if it's cool out.

And the front yard is high in P, so why do the recommend adding more?

As for the calculations, they recommended adding a total of 4 lbs of N per 1000 sq ft over the course of the year and you've already added 1 of the 4, so you'd need 3 more. For the front lawn, you'd want a total of 9.6 lbs of actual N. If you're using 20-10-10, that would be 9.6/.2 or 48 lbs (half in early fall and half in late fall).

For the back lawn, you need another 26.4 lbs of N. With 12-12-12 fertilizer, you'd need 26.4/.12 or 220 lbs (half in early fall and half in late fall).

As I said, I don't know why they're saying to add P to the front lawn. If it were my lawn, I'd probably get something with a smaller middle number for that. If you find something with sulfur in it, it might be worth using some to see if it helps, but I've never had much luck getting the pH to budge over a large area like that.

One other thing I would recommend is that you mulch mow to try to get your organic matter up. That may also help some with the pH.

If there's a Starbucks handy, you could get grounds and spread them on the lawn. This will also supply some N, but with a lawn that size, it would take a LOT of coffee grounds to replace even one round of fertilizer (about 600-800 lbs).

I mentioned that it is often impractical to try to use sulfur to lower the pH of a large area and adding iron is often unsuccessful because it is not in a usable form.

In another thread, David Hall mentioned greensand (glauconite) as a way to help provide iron to lawns with high pH soil. It's not readily available to me, but if you can get it, that might be better than either iron or sulfur.