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We specialize in soil mineral balancing for organic and regenerative growers. Our tests and recommendations are aimed at building a healthy soil life for productive plant growth.

Soil and Water Testing

Logan Labs testing

Soil – Saturated paste – Water

Discount pricing

Amendment Recommendations

Do It Yourself using our online webapp, OrganiCalc


Have us do the recommendations for you

Mentoring and Consulting

With Erica Reinheimer

Co-author of The Intelligent Gardener

Expert in soil mineral balancing

Soil and Water Testing

This is the test for mineral reserves in the soil. It answers the question – how big is my mineral savings account?

This is a great test for gardens, farm soils, yards, orchards or new ground.

The Logan Labs soil test for mineral reserves is either the Mehlich 3 or AA 8.2 test or AA 7.0 test. The test measures the amount of minerals in the soil that may be bio-available, as has been determined by field tests. For example, we know the test for phosphorus works because when we apply phosphorus according to the test results, we get an increase in yield. The Mehlich 3 test uses a mix of acids at pH 2.5 to remove phosphorus and cations from their exchange sites. However, with calcareous (fizzy) soil the test over estimates calcium and magnesium due to the presence of carbonates.  The AA 8.2 is at present the only reliable test for calcareous soils.

This is the test for water soluble minerals. These minerals are most readily available to the plant.

This test is best paired with a soil test (in the Logan Labs “complete” test). We do this automatically when you order a soil and paste test from us. It’s great for anyone growing in living soil, for market gardeners, and anyone growing  a cash crop. By itself the saturated paste test is good for a mid-grow check on mineral availability.

As the name implies, in this test the soil is saturated with water to just above its ability to hold it, and is left for 24 hours for the minerals to dissolve.  The water is then vacuum extracted from the soil and analyzed for its mineral content.  Only a small percentage of the soil mineral reserve will be present in the paste test. This is a very useful test for determining the presence of excess “salts” or dissolved minerals in the soil that could impede the growth of salt-sensitive plants.  It is also very useful for determining whether minerals in the soil reserve are indeed readily available to the plant.

The saturated paste test provides the most accurate information when it is made using the same irrigation water as will be used on the crop.  Irrigation water is rarely pure and likely contain minerals and/or be of a pH that affects the amount of minerals that are dissolved.  There is no additional cost to testing with irrigation water; you just need to provide the sample at the time of testing.

Extras can be ordered with a soil test. It includes mineral reserve tests for Co, Mo, Se, Si and electrical conductivity.

Electrical conductivity (EC) is a measure of the “liveliness” of the soil – how easily charged particles can move through the soil. If the EC is low, the soil may be a bit sluggish at delivering nutrients to the plant roots. If the EC is high, sensitive plants will not be able to take up nutrients as well.

Cobalt (Co) and Molybdenum (Mo) are essential for the bacteria responsible for fixing nitrogen in legumes. These are needed in only tiny amounts.

Silicon (Si) is helpful for reducing stress in plants, making them more resilient to environment stress such as drought or heat. It also help prevent fungal diseases such as powdery mildew. Although silicon is one of the main components of sand (silicon dioxide), the silicon in sand is not available to the plant. This test identifies plant available silicon.

This tests for the two forms of nitrogen typically supplied by conventional “chemical” nitrogen fertilizers. They are very plant available forms of nitrogen.

This test is included with a soil and paste test.  It is a good test at the end of a grow where nitrate levels should be fairly low, the plants having “eaten” it all. If this is not the case, the next grow can be stunted by high salt content.

In organically managed soil, nitrogen amendments are converted almost immediately to nitrate by soil microbial life. We always see very low levels of ammonium on this test.  This test does not tell the whole story – amino acids and other proteins can be taken up by plants, as can entire microbes. It does not give any information about the long term bank of nitrogen in the soil organic matter and soil life. It tells you nothing about the ability of your soil life to fix atmospheric nitrogen. All it gives you is a snapshot of the amount of nitrate in the soil.

There can be a surprising amount of minerals in irrigation water from a well, pond or municipal supply. This tests for the minerals, chloride and salts in water.

Unless your irrigation water supply is rain water or snow melt, it likely contains minerals that will tend to build in the soil. This test is for anyone who irrigates much of the time from a well, a pond, a stream or from a municipal water supply.

Minerals in irrigation water can build up in the soil and harm plants.  We often see this in container plants such as house plants which form a white crust on the soil surface from built up minerals. Mineral buildup requires periodic leaching, i.e. watering enough at one time to dissolve the excess minerals and flush them out of the root zone. A water test can alert you to the potential for mineral build up and the need to leach periodically.

Amendment Recommendations

OrganiCalc is available by subscription in two versions: OrganiCalc for Vegetables and OrganiCalc Pro

Enter your Logan Labs soil test results and the area you want to amend. OrganiCalc produces a list of amendments to balance the mineral content of the soil, along with helpful notes.

The amendments are approved for use in certified organic production (check with your certifier).

OrganiCalc doesn’t recommend amendments that will cause mineral excesses in your soil. It is conservative by nature.

It creates an ideal mineral recipe for your unique soil.

Included with a subscription

OrganiCalc for VegetablesOrganiCalc Pro
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 vegetablesDefault
Recommendations for only OMRI organic amendmentsDefault
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 loamDefault
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
Includes OrganiCalc Pro for Irrigation Water
Required for commercial customers
Access to Soil Analyst forum

Erica and Alice use the spreadsheet version of OrganiCalc Pro to analyze your Logan Labs soil, saturated paste and water tests side by side (or just your soil, or your soil and paste tests). Amendment recommendations may be modified for your particular crop, amendments or location. Erica provides written comments.

This option includes mineral targets specific for the crop, included tested targets for cannabis.

Mentoring and Consulting

Erica Reinheimer is a long time organic gardener and co-author of The Intelligent Gardener – Growing Nutrient Dense Food. She has had the privilege of working with over 1000 soil tests per year for the past 12 years. She is an expert in remineralizing soil for organic growers.

Contact Erica to inquire.

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