Availanble Nitrogen in soil is dependant on how active the Soil Food Web is and that is dependant on the soil temperature. So a low test for N now is not a big concern. Keep in mind that balance is the key, as long as things are in balance there should be few problems. It is when there is an excess of something, which can cause a problem with uptake or useage of something else where the problem lies. pH is good (6.2 to 7.0 is very good) Humus level (residual organic matter) is good (between 5 and 8 percent is optimal). The studies I have seen indicate the lead in your soil will probably not be taken up by the plants, but may cloing to the outside of root crops (carrots, beets, turnips, parsnips, potatoes, etc.) so those should be scrubbed good before eating.

gbig2, My original calculation said 25lbs/1000sq ft (the 250lbs was a joke!, I thought I might be off by a couple %). I found another site later in the day yesterday that had for clay soil 100lbs/sq ft to raise from 5.5 to 6.5 which is probably what Penn State was going by in their recommendation for you. And yes, going organic will definitely help the pH. The nitrogen fertilizers such as Scott's are acidic in nature and will lower the pH of your soil (how much I don't know). Routine applications of these ferts along with normal erosion/acid rain, and its easy to see how we can have such low pH soil in our lawns. Adding back in organic feed/compost/UCG will help cultivate the soil back into a moderate range (again how much and how quickly I have no idea). I had originally thought to just know the pH of the soil but continue with my organic approach, but decided its best to bump it up a bit with the lime so everything is happier. Then my grass might be able to out-compete some of the weeds that have been more problematic in the last year or 2. It's really funny. I moved into the house 4 1/2 years ago and at the time it was the BEST on the street. We are very good friends with the neighbors and they were always ticked that our house had the best lawn...why? Because they did virtually no upkeep. Never watered, never fertilized, cut very infrequently, all the while these other neighbors had lawn care services, watered religiously (light and frequent), fertilized with their chemicals, cut the grass nice and low :), and still suffered from weeds and poor lawns. Unfortunately when I moved in (1st time home buyer) I got sucked into all the wrong things through bad advice (cutting too low, watering too frequently and much too little, using all sorts of chemicals (weed N' feed, Weed B' Gone, etc.). And all this time I would have been better off with a method much closer to the "neglectful" previous owners. Now I cut high and frequently, water deep and infrequently, switched to organic ferts due to my daughter, and my grass (and right now the weeds!) look better than ever. What a difference a site like this brings about.

I'm not sure where to give more explanation and where to be brief. I tend toward verbose even though I try not to be. Feeding food to your soil works to build organic matter because the microbes eat the food and reproduce. They become the valuable life in your soil. Let the soil dry out for an extended period of time and the microbes will die or go dormant. That soil is dead. The old school of organic thought taught that compost was the only thing you needed for your soil and nothing else had any value. Nobody really knew why compost worked but it seemed to work. When I say it 'seemed' to work, well, sometimes it didn't. Inexplicably. If it worked last year, then why not this year? There was a range of success from very dramatic to nothing at all. Fast forward from the 1940s to the 1990s when DNA research was going on. Scientists and students have been growing microbes on Petri dishes in the lab forever. Put a little soil on the agar and you might be able to get a dozen different species of microbes in the dish. Biologists suspected there were more species but how many more was anyone's guess. A dozen species did not explain the complexity of processes attributed to the soil. When DNA testing got cheap enough to run on soil, they found that there were 35,000 species of microbes in forest soil and maybe 15,000 in a typical garden. All of a sudden the life in soil explained the ability of soil to clean itself, feed itself, feed plants, protect plants, and cause disease when the normal balance was tipped. Later DNA testing showed as many as 100,000 different species of microbes. Excellent, finished compost has all these microbes in it. Compost is made by tossing food in a pile and letting it rot. Organic fertilizer works by tossing food on the ground and letting it decompose. In this scenario, rot and decompose are exactly the same process. For compost it happens in a pile. For fertilizer it happens on the surface of the garden. In the compost pile the microbes live there and decompose the banana peels as you toss them in. When the banana peels are gone, the microbes go to sleep or are consumed by other microbes. The point is the food that went into the pile disappears leaving only the microbes. Any plant food those microbes may have produced would be consumed by other microbes instead of by plants. All the value goes into the pile and stays there until it is gone. When you fertilize on the soil instead of into a pile, the decomposing microbes live out in the garden and continue to help out in the garden instead of in the pile. Some of the microbes produce ready-to-eat plant food. If they do that in the pile, your grass misses the benefit. Here is a picture showing the effect of applying alfalfa pellets to the lawn 3 weeks prior to the photo. This photo was posted here at GW last year. Note how the fertilized zoysia is more dense and a deeper color of green. You can see this effect every time you apply alfalfa, not just sometimes. This was not an experimental patch at a university - it was someone's home. If you would like to try this at home but don't want to buy 50 pounds of alfalfa, try it with a small bag of dry dog or cat food. They have the same animal feeds in them as you get at the feed store. The rate is 20 pounds per 1,000 or 2 pounds per 100 square feet. So that would be 2 pounds on a 10 foot by 10 foot area. Moisten it so the food gets too soggy for birds to carry away. Then come back in 3 full weeks to see the difference. It should look like the photo above only bigger. If you want to scale down to 1 square foot, then use only about a handful. Leaves will not decompose without moisture. If you have had a moist winter, then the leaves should be decomposing. Look for them. If they look fresh, then they are not getting enough moisture. They should have mold spots at least.

I'm certainly not an expert at phosphorus chemistry, but I always understood that when you add any phosphates to soil the phosphorus quickly gets "fixed". As in, it binds to calcium in alkaline regions, or aluminum or iron in acidic regions, and doesn't "last" in the plant-usable form. So the phosphorus doesn't go away at all, but just gets latched up in a plant-unusable form. At that point, the art becomes pushing the pH toward neutral. That will gradually release the phosphorous as phosphates. Be careful about spreading the phosphorous amendment uniformly. I understand that when it gets fixed, it becomes highly immobile. As in, if untilled, it'll move less than an inch a year. So your issue may be BOTH a chemical lack of phosphorus and acidic soil. That is, just throwing a lot of phosphates on your soil isn't in itself a good long-term solution.