Soil Testing for nutrients

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Soil testing for nutrients will help to grow healthy plants that achieve good yields.

image of a no till living soil bed with various plants this is the soil i used for testing for nutrients

What is Soil

Soil is made up from minerals, organic matter, air water and life which provides the plants with nutrients and a place to grow.

Dirt is devoid of available minerals and life making it a poor choice to grow you prized plants.

By creating a healthy soil and maintaining it, we can grow healthy plants that achieve good yields.

So how can we determine if our soil is providing all the necessary requirements?

By building your own soil using Temple Growers recipe.

But what if you already have one you have been using and would like to keep it going. Or would like to create one of your own using locally sourced inputs.

By utilizing soil test kits and testing the soil for nutrients and Ph we can be assured that it will meet the minimum needs of the soil.

Making it easier to get things right and help discover what may be causing a deficiency.

Image of a 50 gallon fabric pot full of soil this is the initial soil created to be tested for nutrient levels

Testing soil for nutrients is important for optimizing our plants growth and production.

To ensure your Soil is providing the required nutrients for the plants you can run a few tests.

A good soil will have the proper levels of Nitrogen, Phosphorus, and Potassium along with all of the micro nutrients.

Soil tests kits can be a valuable tool for growers who mix and or reuse their own soil.

This type of test kit is limited and will only test for Ph and NPK, I usually add Azomite for trace minerals and epsom at the beginning of each grow.

Testing your soil does not have to be complicated, it can also be a fun project and learning experience for you.

Soil Ph

Cannabis plants can grow well in a slightly acidic soil with a Ph between 6-7. This is the Ph range for optimal nutrient uptake and plant health.

Soil chart showing Ph ranges for nutrient uptake by plants

As we can see from the chart, as the Ph increases many micro and macro nutrients become less available.

Soil with a low Ph can cause elements like aluminum, iron and manganese to become soluble and toxic to the plants.

How can you as a grower ensure that you are providing the plant with the necessary requirements of a healthy nutritious soil.

By utilizing soil testing you can be sure the necessary nutrients are available for the plants.

Home test kits and soil Ph meters are common tools used to test your soil.

image of a soil 3 way meter used in testing the soil for Ph level

This can be done with a couple easy to use and readily available tools.

The use of Ph meters like the one shown here can be used to check your soil for changing conditions (also great for learning to water plants).


Using the soil Ph meter is as easy as sticking the probes in the soil, and wait for the reading.

Your normal readings may show a 6.5 Ph, This is the ideal range. You may notice the Ph rise or fall from the normal readings letting you know it may be time have a closer look.

To check the meter for accuracy you can place the probes into 6.5 Ph water.

It may or may not read exactly 6.5 where it should, But this will give you a reference point to work from.

Soil Test Kit

This is the soil test kit I use. Kits like this are available online and from most garden centers.

Image of a soil testing kit available at most garden centers used for nutrient testing


With this soil test kit we can test the Ph, Nitrogen, phosphorus, and Potassium levels in the soil.

Allowing you to see if there are any deficient or excess nutrients.

The information that you have collected from soil testing can be valuable to determine what the soil may need.

This allows you to decide which amendments may be needed to regain nutrient balance in our soil.



How to Test Your Soil for Nutrients

The process of testing soil is easy to do and requires little time. Soil test kits come with instructions for use.

This home soil test kit includes a plunger/filter, vials, reagents and charts to test the soil, and interpret the results.

image of whats inside of the soil nutrient test kit



To prepare a the soil sample you will need.

a clean plastic or glass container

a garden trowel or something to dig with.

The first thing you will want to do is clean the tools you’re using to collect the soil sample.

You only want to test what is in the soil.

Next you should choose a couple spots and to dig down 6-8 inches.

Acquire samples from multiple spots if possible.

This will give you better picture of overall soil health. I usually collect about a cup worth from my pot.

Mix the soil samples thoroughly.

Remove all of the larger pieces of organic material.

Spread the material out in a thin layer and allow to dry,

image of soil spread out on white paper towels to dry prior to testing

Using the instructions from your kit.

image of the Ph sample showing a Ph of approximately 6.5 Ph
image of the test results from nitrogen testing showing a slight deficiency
image of the Phosphorus sample showing that it is in the sufficient range
image showing the potassium test sample in the sufficient range




Using the results from the soil nutrient test kit

With all test completed and results in hand, you have the information needed to re-amend the soil.

Your goals for the soil will determine the amendments you choose to use.

You may also prefer to use a diverse selection of amendments. (fast, medium and slow release) to create and maintain a stable soil to use over many grows.

I re-amend the soil with medium and slow release nutrients to maintain nutrient availability,

If you results show a depleted test, you may opt for something with a more immediate availability.

I also use limestone to raise pH or elemental sulfur to lower pH of my soil.

But your inputs may differ.

There are many good sites to learn about soil amendments to help you build a great soil for your plants.

If your needing help diagnosing a deficiency Percys check out the sick plant section


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