A Toolkit to Measure Soil Quality and Biological Integrity

Sponsored by Heliae® Agriculture

There are likely measurements and metrics you are using to assess soil health—but what data points are you using to interpret results? Are you looking at what you’re learning through a quality lens?

As an industry, agriculture has done a great job of providing plant available nutrients, and while that advantage is still exciting, the next frontier for agriculture lies in the soil microbiome. You don’t have to look hard to find a video or article about the importance of the soil microbiome and how putting that bacteria and fungi to work can help support your crop goals, and every video and article emphasizes the same message: To achieve high performance soils, you must focus on more than nutrients.

Innovative producers, those who are always thinking outside the box, already know this. They know that a holistic approach is required to reach their soils’ full potential.

Plant shoots growing in black soil

A Holistic Approach

Soil has three major components that must be managed for optimum performance: chemical, physical and biological, and each of these properties offer a grower the opportunity to collect data points that can and should translate to management opportunities. For decades, production agriculture and soil scientists have had a good working concept of the physical and chemical properties of the soil; we have known how to amend, add and manipulate nutrients to boost yields, reduce compaction and improve conservation. We know that the chemical and physical properties of our soil determine plant-available nutrients; that pH also controls parameters that can tie up crop nutrient availability and that texture impacts a field’s ability to store and release nutrients.

What we haven’t had a good handle on is the biological properties of soil. Soil biology has, in large part, been represented by an unqualified percentage of soil organic matter (SOM) on a soil test. However, we are beginning to learn that the soil biological properties: the interactions, exudates, and population diversity represented, hold the greatest potential for both soil health and soil quality advancement.

Often used interchangeably, the differences between soil health and soil quality are marked, and as the mystery of SOM and the soil microbiome lessens, biological management through the interpretation of collected data points is providing greater in-field management opportunities.

So, what is the difference between soil health and soil quality, and should one garner more discussion and attention? The answer is a resounding, “Yes”.

Soil health is the interaction between organisms and their environment as well as the properties provided by such interactions. Soil health is a collaborative effort of all three properties working in unison, and, thus, management is a holistic endeavor that looks at the relationship and improvement of all three properties equally. Soil health hinges on the knowledge that soil is partly alive and all management strategy must first consider what can be done to promote and protect soil life. This concept is known as biological integrity—when you have improved biological integrity, you have better soil health that can be measured and quantified.

Soil quality, on the other hand, lends a more antiquated utilitarian approach to focus on the success of the soil in completing its “job” of supporting a growing crop.

An Appetite for Biological Integrity

Biological integrity is enhanced through the population size and diversity of soil organisms: bacteria, fungi, arthropods…the list goes on, and their common denominator for attraction is food source. The food source matters for attraction, growth and added population diversity within the microbiome food web.

What is that food source?

If you want to feed your microbiome you have to have active carbon. That’s the carbon in the soil that is doing all the work: helping to promote aggregation, holding onto different nutrients cations and anions—it’s the key ingredient in the recipe. And if you think of a diet, what you feed bacteria and fungi matters, much like balancing our own diet, micro and macronutrients matter. A well-balanced diet will promote both diversity and abundance below the soil’s surface because there are different food stuffs and different macromolecules for those bacteria and fungi to eat.

A nutritionally balanced food source option is microalgae. And while feeding a growing and diverse soil microbiome population of bacteria and fungi, microalgae also confers both crop production and soil health benefits when used in a crop production program.

Adding a nutritionally balanced food source to increase biological integrity also increases the amount of EPS or “glue” holding soil particles together. These glues are produced by different microbes and as diverse populations increase, more “glue” is produced. And it stands to reason that when you increase aggregation, i.e., structure, you also increase water holding capacity. This allows more water into the soil profile from irrigation and rainfall events, and at a microscopic level, you can also store more water around and between aggregates.

This is just the tip of the soil microbiome “iceberg”.  As agriculturalists, we continue to learn more everyday through research discoveries an in-field management application. And we share what we learn, even in a new, socially distanced paradigm of communication. To learn more about:

  • The Rhizophagy Cycle- what it is and why it matters with Dr. James White
  • Soil Health Qualitative and Quantitative Assessment
  • Feeding the Microbiome

and how to apply what you have learned in your cropping system, register for the upcoming 2-day webinar series, “Rethinking Soil Health”. Every live session will offer CCA continuing education credits and provide a live Q&A session. Registration is free and space is filling fast! Join the soil health conversation at: https://phycoterra.com/2020/09/23/heliaeagriculture-presents-rethinking-soil-productivity-a-2-day-webinar-for-growers-innovators-investors/