Tag Archive for: soil test

Steps To Understanding A Soil Report And How To Use That Information To Take Corrective Action

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Now before we begin, we need to clarify the scope and type of soil report we are using today. 

The sample report we are using will be reflecting values in parts per million (ppm) derived from a Mehlich 3 (M3) extraction process. We are assuming we are utilizing AgriGro’s prebiotic technology to get maximum nutrient efficiency from those results. 

A good comprehensive soil report will have results for the macronutrients phosphorus (P) and potassium (K), the secondary macronutrients calcium(Ca), magnesium (Mg), sodium (Na), sulfur (S), and also essential micronutrients such as boron(B), copper (Cu), iron (Fe), manganese (Mn), and zinc (Zn). Some additional nutrients you may want to check as you get more thorough are chloride, cobalt, moly, nickel, and silica. 

Let’s start with one of the most confusing or misunderstood numbers on this report. The CEC, which is the Cation Exchange Capacity (CEC) that was either measured, calculated or estimated for the soil being tested. Sometimes it is shown as ECEC for estimated CEC or CCEC for Calculated Cation Exchange Capacity. Regardless, the number represents the total milliequivalents (meq) or positively charged cations that 100-grams of this soil can hold. In other words, you could say it reflects how big of a sponge your soil has. The more clay in your soil the bigger your sponge. The higher the CEC number the more nutrients are retained on a soil particle. 

There is not necessarily a good or bad CEC reading, it just tells you what type of soil you have and will indicate how much material will be required to add or remove to balance the soil based on its holding capacity for cations. 

The primary cations are hydrogen, calcium, magnesium, potassium, and sodium.

This chart copied from an agronomy handbook produced by A & L Labs shows the desired levels of three of these cations in balanced soil. To compute the desired balanced level of sodium you can multiply the CEC by 3.42 to give you the ppm desired. To convert ppm to lbs./acre, multiply by two. 

You may have noticed that hydrogen is also missing from this chart. Hydrogen can be looked at like a placeholder on the soil. When calcium, magnesium, sodium, or potassium are missing, hydrogen takes its place on the soil particle. The more hydrogen on the soil particle the lower the pH . As you replace hydrogen with a missing cation like potassium or calcium the pH will move up. When the pH is at 7 you will not have any hydrogen showing on your soil report. It is desirable to have 10 to 15% hydrogen for good exchange and availability of phosphorus and micronutrients.

The next section of the soil report we want to observe that will quickly tell you the condition of the soil will be the area that summarizes the percentage of saturation of each of the five main cations: Potassium, Calcium, Magnesium, Hydrogen and Sodium. 

If your CEC is showing higher than eight then you will want calcium percentages to be around 70% and magnesium around 10%, followed by potassium above 2% and sodium less than potassium. 

If your CEC is below eight then you can have adequate calcium around 60% and magnesium around 20% with a minimum of 3% potassium and sodium less than potassium. 

After these percentages are investigated and you have determined what cations are deficient or in excess you then can look at the extraction results to determine quantities needed to correct the soil. 

Phosphorus is not a cation. On an M3 test for adequate amounts, it should be around a minimum of 25-ppm or if we multiply by 2, 50 lbs./acre and remember these figures are only valid when utilizing IgniteS2® or SeedMaxx® prebiotic technology. There is virtually no return from pushing P levels higher than 30-ppm. 

Next if we have potassium less than 2% on a CEC 14 soil, we need to look at our results and then check the chart to see what level the potassium should be in order to be balanced. For example, our chart shows 164-ppm for a normal 2-5% range on a 14-CEC. Our results indicate we have extracted 132-ppm. 164 minus 132 = 32-ppm of Potassium deficient. 32-ppm x 2 = 64 lbs/acre of lacking potassium (K). 

We now have to decide how we are going to add this 64-lbs. of potassium. There are many options for adding potassium either liquid or dry to the soil and you could also decide to just feed the plant now that you know it is deficient and yield-limiting nutrients in this soil. 

The same determination and method should be followed for all the nutrients that have been tested. 

For an M3 extraction process, you should use these values for a minimum desired level of all elements that are not shown in the cation percentages… 

Sulfur: 24-ppm 

Boron: 0.8-ppm 

Copper: 2.0-ppm 

Iron: 45-ppm 

Manganese: 40-ppm and less than Iron 

Zinc: 6-ppm 

Molybdenum: 1-ppm 

Cobalt: 1-ppm 

This information should put you well on your way to becoming proficient at analyzing a soil report and putting a plan in motion to improve or maintain your soil when paired with AgriGro’s prebiotic program.



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Providing Optimum Plant Nutrition

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Providing optimum plant nutrition has always been a discussion for producers who are looking to maximize crop production and profitability.  Many people have researched product application practices seeking high production and return on nutrients applied.  For years, the justification for applications has been based on Liebig’s law of the minimum.

In 1828, German botanist Carl Sprengel developed the “Law” or “Principle” of the minimum.  It became more well known when German Biochemist and Professor, Justus von Liebig, publicized and studied it more widely starting around 1940.  The “Law of the Minimum” in 1940, states that the rate of growth of a plant, the size to which it grows, and its overall health depends on the amount of the scarcest of its essential nutrients that is available to it.

Although this concept can and has provided some value to producers for many years, it is missing a key element – the condition of the barrel.  For years producers have chased the lowest stathe of the barrel with applied macro and micronutrients without addressing the condition of the soil that they apply nutrients to.

Improving the health and balance of your soil is not always a quick process but is the most important element to address before chasing the scarcest nutrient on a snapshot soil or tissue test.  Applications of harsh chemicals, fertilizers, and heavy tillage have created flaws in the barrel (soil) that we depend on for farm profitability.  Addressing the lowest stathe of the barrel doesn’t always work if we don’t first evaluate the condition of our soil.

Fortunately today we are going back to the basics with the increased use of cover crops,  No-Till/Reduced till practices, and addressing soil biology. It’s exciting to see how agriculture has changed over my 23-years of supporting professional producers in the Midwest.  As producers address the factors that are limiting the soil’s ability to hold optimum moisture, cycle nutrients, and provide a prolific root environment first, the soil can and will work for you.

For 40 years AgriGro has manufactured products that support producers in increasing profitability by mending the barrel (soil).  If you haven’t experienced the benefits of AgriGro products on your farm, I would encourage you to give them a try.




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Manage Soil Compaction and Watch Your Crops & Profits Grow

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As we close out one growing season and prepare to get back in the fields for another, what strategies do you have in place to reduce soil compaction and its yield dragging impact? Considering that today’s tractors, combines, and field equipment are only getting bigger, it’s vital to understand the impact that soil compaction has on your soil, crop health, yields, and bottom line profits. With margins tight and maximizing profits essential, there has never been a better time to give this important issue serious consideration. 

Soil compaction is magnified through many of the routine field operations that are often performed under less than ideal conditions when soils are wet and more susceptible to compaction. The use of heavy equipment and tillage implements can cause lasting damage to the soil structure as the surface of compacted soil is much more likely to seal off – simply meaning air and water have a harder time moving down through the soil. As compaction builds, water accumulates on the surface and moves downhill creating a greater potential for soil erosion and water runoff,  carrying eroded topsoil, applied fertilizers, and pesticides along with it.  

Soil compaction causes multiple issues throughout the growing season from planting to harvesting.  For a seed, compaction causes greater stress on the seedling during germination and root expansion because it has to work much harder to develop and spread throughout the soil.  A critical aspect of the consequences of compaction is air and water do not have the ability to effectively travel throughout the soil resulting in more areas of standing water, poor drainage, and crop damage due to the seedlings and roots potentially suffocating.

Here’s a list of how compaction can impact your soil and crop production…

  • Causes soil pore spaces to become smaller and more compressed.
  • Reduces airflow in the soil, restricting healthy plant respiration.
  • Decreases the rate water can penetrate and percolate in the soil root zone and subsoil.
  • Increases the potential for surface water ponding, water runoff, surface soil waterlogging, and soil erosion.
  • Reduces the ability of any soil to hold water and air which are necessary for plant root growth and function.
  • Reduces valuable biological activity in the soil.  
  • Restricts crop emergence as a result of increased soil crusting and deteriorating soil conditions.
  • Significantly inhibits root growth, limiting root penetration, and the volume of soil explored by roots into the subsoil.
  • Compaction restricts root development and exploration, decreasing the ability of all crops to utilize nutrients and water efficiently from soil.
  • Compaction is a Yield Killer.

You will pay a price for soil compaction – all of these factors increase crop stress and lower yields resulting in loss of profits.

There is a simple way to cost-effectively reverse the effects of compaction… Respire® by AgriGro.


Respire® represents the next generation of technology in the fight against compaction and its yield-limiting impact. Respire® is an anionic, soil-amending surfactant that addresses a wide range of soil compaction problems common in today’s agriculture. Because the soil itself is chemically altered, results are longer lasting than those obtained via surface water surfactants. Benefits are visible after first watering or rainfall and will continue the entire growing season before additional applications are required.

Respire®  works to offset compaction by improving soil structure, drainage, and tilth to maximize yields and support overall soil and plant health. For conventional tillage or no-till applications, Respire® helps support a healthy growing environment so your crops can reach their genetic yield potential.

Good soil structure is the number one defense the soil has against compaction and it determines the ability of any soil to hold and conduct water, nutrients, and the air necessary for maximum root growth and plant development. Respire® is the perfect compliment to AgriGro’s line of prebiotic products like IgniteS2® and FoliarBlend® and can be used in combination to maximize the soil’s microbiome to reduce compaction and improve crop production.  When these products are used together they have a greater impact on soil health and crop production with Respire® affecting the physical and chemical properties of the soil while IgniteS2® and FoliarBlend® enhance the biological life of the soil to help naturally fight compaction and improve overall soil and plant health and crop yield.

For more information on Respire®, click on the link below and get started today. 





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When Should I Run A Soil Test?

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In order to maximize crop production, testing the soil is key. But many wonder, how often should I run a soil test? Here is the information farmers need to know:

When should I run a soil test?

The short answer is now, if your most recent soil reports are more than two years old. If you have never sampled before then I would suggest setting up a plan to sample annually when you have time, and the fields are accessible. This can be any time of the year – spring, summer, fall, or winter. Once you have started sampling during a season you should continue with that schedule. The reason for this is to give you a more accurate comparison from year to year to see what changes have actually occurred from your management of nutrients.

If you pull samples in the fall one year, and pull samples in the spring the next year, it will appear that you have gained nutrients and could cause you to make a decision that would lower your yields. Spring soil readings generally will be higher than fall readings. So, it is preferable to stick with pulling samples at the same time as previous tests were taken for an accurate comparison.

Do I need to test for anything other than potassium, phosphorus and pH?

Absolutely, you should be getting a complete soil report that includes all micro and macronutrients including secondary nutrients such as sulfur, magnesium, sodium, and calcium. It is not possible to determine what may be needed to optimize yields from just two nutrients and a pH reading. At last count, there were more than 14 essential nutrients that have been identified for plants.  If you do not test for these nutrients you may never determine what is needed for top production.  

Where should I send my soil sample?

Send your samples to any commercial Ag lab that can provide a report that contains the calculated exchange capacity (CEC) of your soil, all five cations with the base saturation percentages calculated (potassium, calcium, magnesium, hydrogen, and sodium) and micronutrients extracted using a Mehlich 3 extraction process. There are many good labs across the country that can provide this protocol, including Waypoint, Midwest, Brookside, etc.

Pricing is normally $15.00 – $60.00 per sample.

What should I use to pull samples?

Obtain a stainless steel soil probe for this purpose and use it to pull 5 to 6 inch deep plugs from the sampled area.

Where should I pull samples and how many?

This can be a difficult question to answer depending on what you are trying to accomplish and the size of your budget. If you have soil reports from past years, sample the same areas for good comparisons.

If you are starting off and trying to determine why a certain area does not produce as well as others, pull four or five probes from the poor area for one sample and pull for 4 or 5 probes from the best-producing soil for a second sample.  When you receive your two reports you should be able to readily compare the differences and then feel confident in what your plan of action should be to improve the poor areas.

Why is testing essential?

Regularly testing your soil will ensure that your input dollars are being spent wisely. AgriGro® offers prebiotics, fertilizer treatments, and other crop inputs that can enhance your farming efforts while boosting the soil’s biodiversity. Locate an AgriGro® dealer or contact our team to learn more about the science behind our products..