remineralizing your soil
OrganiCalc: Logan Labs soil test interpretation
Convert a test report into a list of recommended amendments
All recommended amendments are approved for organic use
Eliminates math errors
Trusted by soil analysts worldwide


OrganiCalc for Vegetables | OrganiCalc Pro | |
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Designed for Logan Labs std soil test reports - Std M3, AA, AA8.2, extras, BFA Ag-dyn3 | ![]() | ![]() |
Analyze as many soil test reports as you care to | ![]() | ![]() |
Trusted algorithm for choosing amendments | ![]() | ![]() |
Recommendations for vegetables | ![]() | Default |
Recommendations for only OMRI organic amendments | ![]() | Default |
Error checks for typos | ![]() | ![]() |
Adjusts for sample depths other than 6" | ![]() | ![]() |
Adjusts for area to be amended | ![]() | ![]() |
Adjusts for depth to dig in amendments | ![]() | ![]() |
Choice of US or metric units | ![]() | ![]() |
Choice of Nitrogen target | ![]() | ![]() |
Choice of 2 N-P-K fertilizers with "best fit" N-P-K hint | ![]() | ![]() |
One custom N-P-K fertilizer | ![]() | ![]() |
Choice of cation targets for sand, clay or loam | ![]() | Default |
Edit Ca, Mg, K and Na % saturation targets | ![]() | |
Enter up to 6 custom carbon-based N-P-K fertilizers | ![]() | |
C:N ratio of amendments calculated | ![]() | |
Choice of P, S, B, Fe, Mn, Cu and Zn targets | ![]() | |
All mineral amendments may be customized | ![]() | |
Form remembers last entries | ![]() | |
Required for commercial customers | ![]() | |
Access to Soil Analyst forum | ![]() |

The right minerals can make all the difference
I was mineralizing a row of broccoli and ran out before the end of the row. The one on the right missed getting boron, gypsum and feather meal.
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You can order Logan Labs soil tests on our website, here.
Acid soil loving crops
If you are growing blueberries, rhododendrons, potatoes or other such plants, the recommendations are good, as long as the pH is low enough. Just don’t add the lime or manganese OrganiCalc recommends.
Pastures
These recommendations are for growing nutrient dense food, not for pasture. Aside from the expense of bringing large areas up to these levels, herbivores are very sensitive to changes in taste. Mineral application limits are much lower for pastures. Consult an analyst experienced in pasture management. Contact Erica@GrowAbundant.com, and we will share what we have learned about pasture management.
Your soil is already balanced
Usually this happens after a few years of soil mineralization. Your soil settles to a point where the plants are growing very well. You don’t want to disturb this equilibrium, or lose valuable (cation) nutrients. You want to add only enough of the anion nutrients to grow a good crop: nitrogen, sulfate-sulfur and boron.
When your soil is mineral-balanced, it’s time to really focus on the biology. 5% organic matter is a nice number where summer is hot; 8 to 9 % is a good number where summers are coolish, such as in the Maritime northwest. Organic matter over 30% is more than enough.
Finally, if your soil is otherwise balanced and you have excess Ca, don’t try to fix it; leave it alone.
The table on this page shows the mobility of minerals in their elemental form; they are all mobile in their sulfate forms, especially when applied with water. So, if you need zinc (which is immobile in the soil), you can dissolve it in water (as much as you can) and apply it during a rain event. It will penetrate to the depth of the water. The same is true for copper and iron.
*Note that OrganiCalc is designed to prevent excesses of any nutrient in the soil and will not recommend an amendment containing a element that is already sufficient in the soil. So if your bag of XYZ contains magnesium and your soil already has sufficient magnesium, OrganiCalc will not recommend it.
Get a soil test from Logan Labs. Enter it into OrganiCalc, for DIY Logan Labs soil test interpretation. Assemble the recommended amendments. Add the amendments to your soil. Grow delicious, nutrient dense food.