Thanks for the response.

Phosphorus, potassium, calcium and magnesium were all measured in lbs. per acre. Phosphorus was rated medium; potassium, high; and calcium and magnesium, very high. The micronutrients were measured in parts per million. They were all rated as "sufficient".

Does this help?

Were the test results the total amounts of the elements or the available elements? It may take a good soil synergy to release those elements to the plants.

One reason for the different amounts, how long it takes to release the nutrients. Some fertilizers release their nutrients quickly. As a example, ammonium nitrate releases its nutrients very quickly, may require a new application in a month or so. That mostly depends on rain fall, soil etc. Blood meal on the other hand, it releases slower and more safely. For organic fertilizer it is pretty fast but still slower than ammonium nitrate. Cotton seed meal is slower, much slower, but it is also more steady and long lasting. If you want a quick burst of nitrogen, blood meal will get you there. If you want a steady release of nitrogen, cotton seed meal will do the job.

In some cases, it is good to mix both a fast and slow releasing fertilizer. If for example you are really short on a nutrient and need it in the soil and available to the plants soon, mix in a forth or third of quick acting fertilizer and the rest in a slow release fertilizer. The fast acting fertilizer will kick in and give the plants what they need while the slower acting fertilizer is getting started. When the faster acting is gone, the plants will use the slower acting one at that point.

I think what you are missing is the timing. Soil tests indicate a certain amount of nutrient being released in a certain amount of time. It's the time that you are missing. If you take ammonium nitrate rich soil, it will test high in nitrogen. The reason it measures high, it releases so fast and releases all it has at once. If you do the same with soil rich in cotton seed meal, you will get a lower number BUT the number will stay at or close to that level for a longer period of time.

In your case, bone meal will release its nutrients quickly but will be gone rather quickly too, hence the high number. The rock phosphate will still be releasing nutrients long after the bone meal is gone. Since the soil test said medium, I'd put out rock phosphate if it were me. If you have a plants that needs more, mix in a little bone meal to get it started.

Sort of a long post but I hope it explains it better. Sometimes one long post is better than half a dozen short posts. ;-)

I very much appreciate your advice and recommendations. Guess I'll go with 10 lbs. of rock phosphate per 100 square feet.

BTW, is it a myth that organic fertilizers won't "burn" (harm) roots? I always thought that this was one of their major benefits but recently read that blood meal could be harmful. What about rock phosphate, bone meal, alfalfa meal, etc.?

I've never had it happen with any organic fertilizer. I guess if one took a large bag of blood meal and dumped a lot of it into a pot of flowers, it could happen. The only thing I've ever had a plant to burn from, ammonium nitrate. That is strong enough to do it. I think it would take some effort to do this with organics tho.

I do soil tests to but think it worth mentioning that soil tests can be deceptive for organic gardening. When I send a soil sample to a local State lab, they test for commercial fertilizers not organic ones. They do pick up organic fertilizers but the numbers can be off quite a bit. The commercial fertilizers are usually water soluble and get picked up by the equipment pretty fast. Organic fertilizers can take weeks, months or more to become available. The equipment won't pick up that.

Hope that helps.

Thanks again. Your explanations are always helpful.

I took another look at the several soil tests. At the end of each test report, the type and amount of fertilizer recommended was listed. And it was always an inorganic fertilizer, such as 5-10-5. The only reference to organic fertilizers came in an accompanying pamphlet that also dealt with general instructions for liming, organic matter, potted house plants, soil mixes, etc. The information was brief and to the point: "If phosphorus falls into the medium or low category, add 10 lbs. of bone meal or rock phosphate." Pretty general stuff.

But it's understandable. I would guess that most soil tests are requested by commercial farmers and others who typically use inorganic fertilizers.

Thanks again.

I wish when we did soil tests, we could have a check box that we want to have a organic soil tests with organic recommendations. I also wish soil tests would show more info about trace minerals such as moly and such too.

The way I do, if it says low, I add some of that. If it says medium, I add only small amounts if any. If it says high, I try to avoid adding that at all if possible. I'm trying to get my hands on Azomite to get some of those trace minerals that they don't even test for but plants need. After all, organic gardening is about health, the soil, plant and person eating the plant. The plant can't be healthy if the trace nutrients aren't in the soil. They're just recently finding out how important moly is to plants. The amount of moly needed is tiny but important.

This is a lab that I think is based on organic gardening. It is pricey tho.

http://www.loganlabs.com/testing-services.html

I guess one could get a soil test once from them and then only get them to test every few years, using normal soil labs in between.

A soil test is one tool to use to aid in getting soil into a good healthy condition, but an important one. Since changes in nutrient levels with organic methods is slow there is no good reason, once balance is achieved, to have soil tests done every year.

If adequate amounts of organic matter are maintained in the soil all nutrient levels should be where they need to be, without adding other materials. Trace nutrients are just that, small amounts are needed for good healthy plants. Excess amounts of any nutrient can interfere with a plants ability to use other nutrients. Adequate amounts of the major nutrients fall within these numbers,

Phosphorus 25 to 85 parts per million

Potash 200 to 400 parts per million

Calcium 1500 to 4000 parts per million

Magnesium 300 to 800 parts per million

To arrive at pounds per acre multiply ppm times 2.

But more important than the raw numbers is that those nutrients be in balance, not5e the ratios of these are roughly 5 to 1 and that is where you want to be.

I tell new gardeners to test for a couple years or so until things level out then start skipping years. We both give good advice on that. That works for most soils and since organic fertilizers are so much slower, it should work better for those. Also, as you also point out, all the organic matter also helps keep things from changing quickly.

I'm working toward the "Back to Eden" garden style and given it is based on large amounts of organic matter, it should balance itself and not require much if any testing. I'm just waiting on the tree cleaning people to make their next round. I did help get my neighbor set up to use that method tho. This will be their first year with it. Their garden is small compared to mine. Mine is about a half acre. Theirs is maybe 1/4th of that. I'm looking forward to seeing the results even tho we are told not to expect a lot the first year.

The numbers in the NPK label are the percentages that are immediately available. Rock phosphate has 3% immediately available phosphate but 20% total phosphate. Whereas bonemeal has around 12% total phosphate, all of which is basically immediately available. So rock phosphate has more phosphate but it released into the soil slowly, over a period of years. This is a good reference to organic fertilizers:

http://www.ext.colostate.edu/mg/Gardennotes/234.pdf

gekkodojo, thanks much for that link. I'm always looking for that sort of info but it is sometimes hard, almost impossible, to find.