The only labs specializing in micro-organism analysis of soil, to my knowledge, are the Soil Foodweb labs (info here: Soil Foodweb web site). Other labs are branching into this area, but the Soil Foodweb people have the most experience.

You might find some help here:

list of soil testing labs for organic growers but you'd need to check whether they have the equipment and expertise to do the microherd analysis you're looking for.

Generally speaking if you have sufficient humus levels in your soil you will have the soil microbes you need in large enough quantities and you would not need to spend the money for any analysis. One good way to tell how good your soil is is with these simple tests;

1) Structure. From that soil sample put enough of the rest to make a 4 inch level in a clear 1 quart jar, with a tight fillting lid. Fill that jar with water and replace the lid, tightly. Shake the jar vigorously and then let it it for 24 hours. Your soil will settle out according to soil particle size and weight. A good loam will have about 1-3/4 inch (about 45%) of sand on the bottom. about 1 inch (about 25%) of silt next, about 1 inch (25%) of clay above that, and about 1/4 inch (about 5%) of organic matter on the top. Your primary concern is the OM level and yours may be pretty good.

2) Drainage. Dig a hole 1 foot square and 1 foot deep and fill that with water. After that water drains away refill the hole with more water and time how long it takes that to drain away. Anything less than 2 hours and your soil drains too quickly and needs more organic matter to slow that drainage down. Anything over 6 hours and the soil drains too slowly and needs lots of organic matter to speed it up.

3) Tilth. Take a handful of your slightly damp soil and squeeze it tightly. When the pressure is released the soil should hold together in that clump, but when poked with a finger that clump should fall apart.

4) Smell. What does your soil smell like. Pleasant, rich earthy odor? Putrid, offensive, repugnant odor? The more organic matter in your soil the more active the soil bacteria will be and the nicer you soil will smell.

5) Life. How many earthworms per shovel full were there? 5 or more indicates a pretty healthy soil. Fewer than 5, according to the Natural Resources Conservation Service, indicates a soil that is not healthy.

Dig in and look closely at your soil. If you have sufficient levles of OM you wil have the micro herd you need. If you do not have enough OM you won't have enough of the micro herd and until you get enough OM into the soil you never will.

My understanding is that there are so many different species of soil microbes in a given garden plot that doing an analysis could take a lifetime, or two. When you talk of elemental analysis, you are talking about carbon, nitrogen, phosphorous, calcium, potassium, sulfur, and traces of selenium, copper, nickel, and vanadium-have I left anyone out? But soil microbe analysis-I'm not sure how to approach that. I know that there has been work done with nematodes and corn, because I see the adds on tv for agricultural pesticides that kill nematodes, aka "corn rootworms."

A general consensus among many of us who have studied microbiology and soil is, as ericwi states above, "..so many different species of soil microbes in a given garden plot that doing an analysis could take a lifetime...". If you read e.g. Science News or New Scientists you will find that microbiologist are discovering new microbes in the soil almost daily. A vast group of new Pseudomonas were discovered just recently.

Thanks everyone, We are trying to study an organic fertilizer. It so far molds, stinks for about a day after application, and shows higher levels of nitrate after about a week than the "unfertilized" group. We can also tell by blindly smelling the soil after a week or two exactly which ones have been spiked by that "earthy" smell. We tested it against cottonseed meal and two synthetic fertilizers last year as a "control". Outyielded the CSM by 60% or so and showed no statistical difference to the two synthetics, 33-0-0 and 15-15-15. Why I was asking was everyone keeps talking microbes. What does it do for them? I am under the impression that the protien N conversion to nitrate is by the digestion due to the microbes, so that is why I was wanting to "count" the population to see if we were growing the population. I have heard that if I can measure the CO2 levels in a sealed container (respiration), that might be an indication. Hope I am on the right track. Thanks again.

there are millions of individual bacteria in a single spoonfull of good soil - not worth thinkin about beyond the need to feed your soil w/ organic material to keep the microherd healthy
FYI in one gram of healthy soil there can be
500 MILLION individual bacteria of 15-20,000 species
150-300 meters of fungal biomass of 5,000+ species
10,000 potozoa
and 20-30 beneficial nemetodes [preying on the bacteria & fungi]

decomposers in the upper soil layer chemically modify the nitrogen found in organic matter from ammonia to ammonium salts - the process is known as 'mineralization' and is carried out by a wide variety of bacteria, actinomycetes, and fungi, ideally as in composting

as for the nitrogen level changes, nitrogen can be volatile or non-volatile, and if it's "organic" [as should be in your organic fert] that means it consists of carbonaceous compounds like protein and humus, which are stages of decomposition, and the continuation of those changes when you expose the material to the soil and it's microbial component, and especially the air and moisture, will result in the 'freeing' of the nitrate forms of the nitrogen, and 'gassing off' [so being lost to the atmosphere] faster than they can be converted to less volatile forms, like humus

in neutral to acid conditions (pH 7 or below) ammoniacal nitrogen is present as ammonium, but as the pH rises to 8 and above, an increasing proportion is converted to ammonia and will vaporize - no tellin what's happening among all the different materials you're watching, and how each affect the microherd and pH, or how they're affected in return - are you checking the pH of the soil and the fert's?

what's the composition of the "organic fertilizer" and why compare a prepared, possibly balanced, formula against a pure seed meal or worry about the chemical stews at all? are you tryin to increase green matter, like in hay or silage, or tryin to grow a food crop? increased N is not always the measure of success

prolly more than ya wanted to think about?

Bill

Here is a link that might be useful: about the nitrogen cycle

You definitely want to go to the Soilfoodweb website. She sells a book that tells you in detail how to determine exactly what you are looking for using a microscope and stains. She explains what you are looking for and how to count.

I think you're on to something; however, if you are seeing mold with the naked eye and smelling stink, I think you're using about 5 times too much.

I use milk to fertilize 17 plants kept in a hotel room. I can't see any surface changes, but I can definitely smell the sour milk after a day. But a few days later the milk-fertilized soil smells incredibly good.

Ok, I am getting smarter. So what we are seeing is decomposition plus mineralization due to our existing and apparently abundant native microbe population. Our fertilizer is probably 99+% protien so I would expect very little nitrogen to be immediately available (NH3 or NO3). Bill, we didn't even know if this product would act as a fertilizer and we also wanted to take a look on a scientific basis and not on a friends experience, so that is why we compared against cottonseed meal and the two synthetics. We live in west Texas and are not remotely "organic" in our thinking. We are kind of chicken fried steak and mashed potatoes kind of people. My wife and I live on a small farm. She raises butterflies for educational tours and retail sale. She purchased a bunch of chickens for the school children to "watch" while on the farm participating in the butterfly tour. One day I collected the eggs that had been layed around the yard that were in various states of ferment, put them in a bucket and poured them over the fence. That spot stayed wonderfully green two summers ago in our largely arid, almost desert climate. Make a long story shorter...the egg industy here in the US makes millions of eggs that are not fit for human consumption that are deemed by the USDA as "inedible" for various reasons....broken shells, double yolks, no yolks, blood spots, stained shells, etc. The bottom line is they take millions of pounds of this stuff,(egg yolk and white, no shells), spray dry it and sell it to the pet food industry as crude protien. It is a 7-1-0 and very close to a 7-1-1. As I have had this organic observation happen to me on our farm, I have been learning every since. So I am starting to understand...ate at my first organic restaurant actually located in west Texas last Wednesday. I would really enjoy some reseach ideas for this next growing season. We have the support of our local county agent so far. He is with the Texas A&M system. That is also why we have leaned towards analytical proof. The phD at our local state university has been very helpful as well. He is the one who did the reseach with the csm and synthetics. So far the only drawback happened when we put it directly onto the soil surface and did not immediately "rake it in", our cats came and licked some of our application off the ground. Still have the cats. Thanks again for the comments and references. I would love for some of ya'll to try some. Thanks again, Ed

Carbon dioxide out-gassing is the inexpensive way to measure the total microbe bio-mass and its waxing and waning. This method is used to indicate (by inversion) the reducing levels of oxygen in a live compost pile or windrow. Regards, Peter.

A soil biology test is the only soil test worth purchasing. By knowing what critters you have in your soil you can calculate the amount of N P K that the biology will release over the next month or so.

The traditional chemistry soil test is very limited and only tells you what nutrient is there right now, but won't tell you next week or even tomorrow. It only gives you a snap shot of what's there. But only useful with respect to what might be limiting growth in this instant.

I sincerely appreciate the comments. I looked at the SoilFoodWeb the other day. I did not call thinking I would get sticker shock for analysis like that. Our Spring starts in west Texas usually about late Feb...March, so my need for testing the egg stuff will probably outweigh my pocketbook. I can do NO3 and Ortho P in the small lab I work at. I was not aware of the soil biology test kit. How does one aquire that. Thanks, Ed