Compost by itself is not the most cost effective thing you can use. Pelletizing it won't improve that fact. The best way to get more organic matter in the ground is to grow more grass. Grass roots die and slough off every 3 years leaving organic matter in the soil. Those dead roots become food for the microbes that live in the soil. That is one aspect of getting organic matter into the soil.

Another aspect is to minimize the use of chemicals like fertilizer, herbicide, insecticide, and fungicide. Instead you can use organic alternatives like grain based fertilizers (soybean meal, corn meal, alfalfa pellets (rabbit chow), corn gluten meal, cottonseed meal, and even used coffee grounds). These fertilizers provide nitrogen to the plants by the decomposition of protein. Apply any of them at 15 pounds per 1,000 square feet as often as you can afford or a minimum of 3x per year (Memorial Day, Labor Day, and Thanksgiving). You cannot over apply these materials. The best place to get them in bulk is a feed store. As for organic herbicides, there isn't a good one. You might want to spot spray with a targeted herbicide to minimize the effect on the soil organic matter. There are very effective organic insecticides based on live critters which infect the insects with diseases. As for fungus diseases there are a few different materials. Corn meal is one, garlic is another, and there are certain microbes sold for that purpose. Sometimes just washing the grass with soap is all it needs to get rid of the ugly but harmless diseases.

The more you can apply organic fertilizer the faster you will build up organic matter in the soil. The cost per square foot for these grain fertilizers is about 1/15 the cost of compost which means you could apply fertilizer 15 times before you get to the cost of one application of the compost.

Dchall-

I agree with organics. Just wanted to see your opinion on this:

As you said -- getting grass to grow is the best way to increase organics in the soil.

Grass responds faster to synthetic fertilizers because the nutrients are readily available (whereas organics must be broken down). Most will tend to agree with this; particularly when there is soil thst doesn't have much soil life to begin with. (I'm sure those who have cultivated a strong micro herd will see faster response times to organic feedings).

It seems that using synthetic fertilizers might actually better increasing organic matter than using organic fertilizers and compost; the grass will grow faster, producing more organic matter (roots, etc.) into for the soil @ a faster rate. In other words, if growing grass is the best way to introduce organic matter... Then using synthetics would be the most efficient and effective way to increase organic matter.

@owlnsr

I think you are correct.

I can't post the whole article because it would be problematic from a copyright perspective but this article indicates that up to 80% of organic matter buildup comes from suberin and cell sloughing:

early studies suggested that the relative contribution of plant roots to soil organic C stocks is larger than that of plant shoots (Broadbent and Nakashima, 1974). Long-term residue management studies suggest that above ground material has a limited impact on SOM levels as compared to that of root systems.

Campbell et al. (1991) reported that 30 years of wheat (Triticum aestivum)
straw restitution to soils did not modify the carbon
content of these soils. Clapp et al. (2000) observed
that 13 years of maize (Zea mays L.) shoot restitution in a non-fertilized conventionally tilled system
decreased maize contribution to soil organic carbon
(SOC) stocks from 9.1 Mg ha−1 for roots alone to
8.7 Mg ha−1 for roots plus shoots. Results from a
30-year maize experiment indicate that restitution of
maize stalks vs. removal for silage had no impact
on SOC contents (Reicosky et al., 2002). Although
some studies have observed a significant contribution
of crop shoot residues to SOC content (Barber, 1979;
Hooker et al., 1982), this contribution was comparatively smaller than that of roots (Barber, 1979). Little
impact of shoot residues on SOC was also observed in
long-term residue burning studies (Moss and Cotterill,
1985; Nuttal et al., 1986 in Prasad and Power, 1991;
Pikul and Allmaras, 1986; Rasmussen et al., 1980).

Barber
and Martin (1976) and Barber (1979) suggest that root
exudation, turnover and cell sloughing represent an
annual input of fresh root C into cropped soils equivalent to that of the measurable root biomass.

The in situ root growth experiments indicate that
the relative root contribution to SOC has an average
value 2.4 times that of shoot, with a minimum of 1.5
and a maximum of 3.7

Several long-term studies in wheat and maize
systems reported no detectable shoot restitution ef-
fect on SOC contents (Campbell et al., 1991; Clapp
et al., 2000; Reicosky et al., 2002), which supports
the finding that the mean residence time in soils of
root-derived C is longer than that of shoot-derived C.

Several long-term studies
have reported that SOC contents remained unchanged
or were decreased by the addition of shoot residues
to cropped soils as compared to the root contribution alone (Campbell et al., 1991; Clapp et al., 2000;
Reicosky et al., 2002; Soon, 1998).

To raise organic matter by 1% over 1,000 sq feet of lawn you would need to incorporate many thousands of pounds of material, I've read close to 20,000 pounds. The 20 pounds of corn most people apply wouldn't even make a dent.

They synthetic fertilizers contain a lot of salt and other ingredients that are not benficial to creating a sustainable soil profile. Feed the soil, grow the grass! Always use Organics. May cost you a little more initially but will save you money later. Good Luck.

Would Milorganic count as organic matter, or is it just fertilizer?

Milorganite is 40% synthetic Nitrogen. The remaining 60% organic Nitrogen ends up being 12 times more expensive per pound than a pound of synthetic nitrogen.