If you're looking to increase your soil OM, surface applied organic matter isn't really going to help. They've done studies with reclaimed wheat straw and there was no change, and we're talking metric tons of materials. You just can't apply enough of it since most of the carbon is lost as CO2.

Huh? I raised my OM as measured by Logan Labs by 2% pretty quick

Well, if you included the top inch of soil where all the stuff you just applied is sitting and decomposing, then I suppose it would show an increase. But it's a mirage, once it's done breaking down most of that carbon will be gone. In addition, unless you plan on tilling, 90% of your roots are always going to be below that layer so the benefit to the grass is questionable.

Agree with lawniac. Which is why topdressing with compost is a questionable practice.

The OP wants to "add more organic material to my lawn." He did not say he wanted to increase the OM. That is a totally different issue for you guys to discuss elsewhere.

Feather meal is very high in N, which is why it is used in organic ferts. The organic fertilizer chemical analysis gets a big boost from the feathers, but it does not necessarily do what you think or want it to do. If you think of soybean meal as slow release, feathers are glacially slow. Feather meal and hide meal take months to decompose and release the N to the soil. At least that is how it works the first few times you use it. If you reapply feather meal on a regular schedule, it will decompose faster each time as the population of feather decomposing microbes increases in the soil. One of my neighbors in San Antonio had been using it every 3 months and was able to keep her lawn guy employed every week of the year. I couldn't believe it was still growing enough to mow in December, but it was. I tried it and did not get the same results, so I asked her about it. She had been using it for years on the lawn, every 3 months, and I never noticed. The particular brand of fertilizer she was using contained feather meal, blood meal, and poultry litter. The blood meal gives a quick boost and makes it look like the fertilizer is working fast. Then the poultry litter kicks in after about 3 weeks and carries the deep green color for several months. After that the decomposed feathers kick in. By using the fertilizer every 3 months she had a very active population of microbes working all the time. That same fertilizer has changed their formula, so mentioning the name would be fruitless. But you can get the same effect if you have access to feather meal. Blood meal is available everywhere as is any number of grain meals. If I were to offer a suggested mix to make 50 pounds I would start with 25 pounds of feather meal, 20 pounds of soybean meal, and 5 pounds of blood meal. Apply at 15 to 20 pounds per 1,000 square feet. This would be a very potent organic fertilizer.