How to fill out Solomon's soil analysis worksheets
Before I dive any deeper into
soil science, I thought I'd walk you through filling out Solomon's soil
analysis worksheets (which you can download
for free here).
You'll notice there are actually six pages of worksheets in that file,
which consist of two pages each for acidic soils (pH less than 7),
"excess cations" soil (pH 7 to 7.6), and calcareous soil (pH greater
than 7.6). I actually find it much easier to make a
spreadsheet page for each soil sample since the program can do the math
for me, but I'll fill out a worksheet below to help you get an idea of
the process.
Since I sprang for a
test from Logan Labs, as
Solomon recommended,
it's pretty simple to fill out the column of actual amounts. The
only tricky parts are:
 You need to convert from ppm (parts per million) to lb/acre
(pounds per acre) for certain readings. Solomon explains that you
simply multiply ppm by 2 to get lb/acre, which I'm a little dubious
about. His reasoning is that we sampled our soil to a six inch
depth, and soil scientists estimate that amount of earth weighs about
two million pounds per acre. When I start cancelling units in the
conversion, though, I feel like there should be something factored in
to take the atomic weight of each mineral into account, but I stuck to
Solomon's math. (Roland, help?)
 Logan labs reports phosphorus pentoxide instead of elemental
phosphorus, so you need to multiply their result by 0.44 to get lb/acre
for phosphorus.
The target column is a
little more complex, but is mostly basic multiplication. The one
portion that might cause a hiccup is potassium (K)  you get that
amount from the chart at the bottomleft of the worksheet based on the
TCEC of your sample. Similarly, boron, iron, and manganese
targets are based on TCEC, as is explained in the "calculating target
level" column.
Finally, you subtract the
actual amount of each element (in lb/acre) from the target amount to
figure out how much excess or deficient you are. Since Solomon
labelled the last column "deficit", I put excesses in parentheses.
The sample I used is a
pasture that has been grazed with chickens for a couple of years with
no other amendments, so I figure it's probably similar to the soil you
might find in a new garden spot. You'll notice the soil is acidic
and a bit low on organic matter, without as much capacity for cations
as you'd like, and it has too much of a few nutrients but too little of
some others. Tomorrow, I'll move on to the back side of this
worksheet to show you how to deal with those excesses and deficits.
Our chicken waterer never spills on pastures, so
it's perfect for permaculture chickens.
This
post is part of our The Intelligent
Gardener lunchtime series.
Read all of the entries:

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When we are talking about ppm, we first need to know what exactly it means in this context, since it is a fraction of two measurements that have the same unit and is therefore dimensionless. E.g. ppm can be an elongation (in/in), solution by weight (lb/lb) or fraction by particles (e.g. mole/mole).
Assuming that the report is in lb/lb and not in mole/mole, we need to figure out the dry bulk density of soil. We use the dry density because we are interested in the mass ratios of the solids in the soil. The particle density of minerals varies a bit, but not much. The dry bulk density of soil can vary a lot depending on the exact mineral composition, the amount of organics and the degree of compaction. It is generally reckoned to be between 1.01.6 kg/dm³.
Six inches is 1.524 dm. One acre is 404685.64 dm². So this soil would have a volume of 616741 dm³. With the given dry bulk density range, you would have a dry soil weight of 616741986786 kg, or 1359681 to 2175490 lb. So under the abovementioned assumptions, 1 ppm would correspond to between 1.36 and 2.18 lb/acre.
Hi Anna,
One consultant suggests 3 ppm of Mo so the soil microbes work well.
And humans do better with some V, Se, Ag, Cr.
Once you have added greensand and seaweed to somewhere and it has settled in a more detailed soil report would probably be well worth it :).
I gather you have no problem with having enough water :).
John
I'm not finding any Excel worksheets that correspond to the text descriptions on this website or in the addendum IntelligentGardenerworksheets.pdf to which you link above. Are these Excel worksheets really available? I've been attempting to determine if I have enough information to create some of my own, but it would save me a lot of time if such were downloadable. Thanks, db
Anna, thanks for your reply. I'm looking at the figures on this page. I'm not able to arrive at the deficit for K. I see you took 308 from the table (corresponding to TCEC = 9.88) but what is the actual figure from which you subtract 308? Lb/ac = 974, so I calculate a deficit of 666. But your spreadsheet shows a deficit of 305. I must be missing something. I read all of the article without understanding. I see that cell B14 in the spreadsheet shows 613 as a found amount, but the soil analysis shows K = 974. Is that the difference? (Substituting 613 for 974 provides the same result as entered in the worksheet.) In case you have time to reply  Thanks! db
The revised worksheets have been revised and are at http://soilanalyst.org/wpcontent/uploads/2012/12/WorksheetRevision03.pdf This note from Erica Reinheimer: We have recently cut the P rate in half (to allow for future high P compost additions)  this change does not yet appear in the worksheets. Erica also send a revised table of TCEC target levels. (I don't see a way to attach it here. She's erica@growabundant.com) in case you're interested. Thanks for the replies! Regards, db