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Rhizoterra Inc is an international food security consulting company that provides expert guidance for creating healthy soils that yield tasty and nutrient-dense foods.


Owner & scientist, Dr. Jill Clapperton, and Rhizoterra work together with producers and food companies to regenerate the biological and environmental integrity of the land.

Origin Story

Healthy soil is the foundation for healthy food and a healthy world.

Rhizoterra Inc. is an international company that creates information and knowledge pertaining to soil health.  We want everyone to be able to make informed decisions based on science.


Rhizoterra Inc was founded in April 2011 by Jill Clapperton.  The name comes from the Greek Rhizo – meaning root, and terra- meaning earth. Plant roots are what drive the underground carbon cycle, creating soil structure and feeding the microbial community.


When I started Rhizoterra it was mostly an education design company telling the story of these thriving underground communities that have amazing infrastructure (soil structure and water-stable aggregates).  We worked to help people understand that healthy soil means having essential soil services that provide food, filtered water, and carbon storage to name a few.


Along the way, we were increasingly challenged to find ways to measure soil health and worked to develop bioindicators for phospholipid fatty acid (PLFA) microbial community profiles, adapted the Solvita test to be used in crop by farmers, developed standards for using earthworm numbers and diversity as indicators, and are now using the MicroBiometer test to measure soil microbial biomass. We continue to explore technologies that give practical and relevant in


I love to grow and study plants.  Soil health doesn’t happen without plants. So, if “you are what you eat (and don’t excrete)” then what plants are is surely a measure of what is available to them in the soil.


Then there is that whole argument about what is available in the soil and how a soil test measures availability- hmmm.  Eric Kaiser a farmer in Ontario Canada told me about a “gun” that his brother invented that could measure mineral elements in the soil on the spot- Sure Eric- I thought.  Eventually, I called Bruce Kaiser Ph.D., a farm boy and atomic physicist, who invented the Bruker Tracer a portable X-ray fluorescent (XRF) spectrometer.   Bruce helped me to develop calibrations to accurately measure the total amount of macro and trace elements for soil, plant material, food grains, fertilizer, water, etc. in 30 seconds.  Now we can measure the total amount of elements like magnesium, phosphorus, potassium, manganese, iron, and zinc for example in the soil, compare that with what is in the plant tissue, and then grain and know what was available and made available to the plant.  Now we can measure with the Tracer, we can make scans, and see where the elements go in the plant.  IT IS SO COOL. Rhizoterra actively looks for new analytical technologies, tests them, and helps to develop a market for them (if we think they work). Check out our line-up.


Working with dairies and grazing animals has meant Rhizoterra has started creating forage mixes combined with grazing to help heal the land and keep livestock at optimal health.  Increasing the plant diversity in cropping systems with intercropping and companion cropping is another logical step.

With all the people that have mentored me and Rhizoterra on our journey, we learned that the growers and ranchers have done some of the most innovative work in agriculture.  These innovators wanted to share what they were doing with others- so why not add designing and helping to implement field studies to our list of what we do.  This also became about connecting innovative farmers from around the world together to build a network of peers that have a similar goal – to care for the soil, their families, and communities, and grow the best seed, and food possible.

We are constantly asked to endorse or test products.  Growers are always asking me about products and then there was the big question- how do we know it is not “Snake Oil”?  Rhizoterra registers both in the USA and Canada biological and biologically-based products for companies that want to provide their customers with legitimate products.  Registered products have to tell you the ingredients so that consumers can make an informed decision.


I have always believed that one size fits no one.  Rhizoterra is all about customizing to suit the needs, culture, and/or risk tolerance of our customers.  I want people everywhere to share and embrace soil health stories, and demonstrate how healthy soils grow nutritious food healing the Earth and ourselves.

Jill Clapperton

Jill Clapperton PhD is the Principal Scientist and Owner of Rhizoterra Inc.  She is an internationally recognized educator on how to create, measure, and maintain healthy productive soils that produce tasty, nutrient-dense food.


Jill has a PhD in Plant Ecophysiology from the University of Calgary demonstrating the effects of sulphur dioxide air pollution on plant photosynthesis and mycorrhizal interactions.


As the Rhizosphere Ecologist at the Agriculture and Agri-Food Canada Lethbridge Research Centre for 16 years, she initiated research on how to create and manage healthy soils with specific cropping sequences, and cover- and companion- crops using no-tillage. This research had a strong focus on the effects of soil management and cropping practices on soil biota with an emphasis on earthworms and soil microarthropods (mites). 


As the market for individual consulting grew- Jill founded Earthspirit Land Resource Consulting, and then Rhizoterra Inc (a USA based company).  Jill served as a Board Member for the Pacific Northwest Direct Seed Association for 5 years and helped develop and coordinate the Farmed Smart Program that certifies farms as Sustainable and Regenerative. R&D projects with vertical farms led her to grow, process, and manufacture whole-plant “green shot” human supplements with the understanding that all the vitamins, minerals, enzymes, and secondary plant metabolites work together to facilitate health.  Separating out so-called “active ingredients” means we can easily lose most of the whole plant benefits.

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Arvil Stevenson

Avril Stevenson started working for Rhizoterra in 2011 and is the Office and Project Manager. 


Avril’s key focus in Rhizoterra is registering biologically based agricultural products in both the USA and Canada.


She also assists processing facilities with acquiring Organic, Halal, Kosher certifications including Food Safety and Handling requirements, Standard Operating Procedures (SOP), and Compliance and Quality Assurance.

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Sara (Hessenflow) Harper

Director of Networking & Communications

Born and raised in rural Kansas, Sara's farming roots run through both sides of her family. Over the past 20 years, Sara has added to that personal experience with jobs focusing on agriculture in the U.S. Senate, with the national non-profit group Environmental Defense Fund and as a consultant on agriculture, environment and sustainability issues in the private sector.

In late 2017, Sara launched Grounded Growth, LLC — a one-of-a-kind, online membership platform that connects regenerative farmers with emerging food companies and facilitates business development for both.  

In 2022, Grounded Growth became part of the Jill Clapperton Global Food & Farm Online Community -- and Sara became the Director of Networking & Communications for Rhizoterra.

Our Projects

Rhizoterra gets to work with some amazing people.  Here are a few of the major projects we are involved with.  Click on the image to learn more about each one.

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Our Online Community!

We are a private, supportive, ad-free, global social network that provides information and connections to help you understand the science, practice, and outcomes of improving soil health.

The online community is led by Rhizoterra's Dr. Jill Clapperton and managed by Sara Harper.  Members of the community have access to our video streaming library with hour-long, original interviews with the best soil health doers from around the world.  Members also get to "Ask Jill" any questions they have during her weekly online office hour.

Curating and managing all this content takes work and since we do not accept advertising or allow promotions in the network, it is instead funded by a monthly or annual membership fee.

Click here to learn more or join.  If you'd like to have a tour of our online community, send an email request to Sara Harper.

Our Podcast

How does the health of the soil affect the flavor of our food?  How do the farmer's choices, the weather, and the soil microbiome shape the taste of our food?  Who are the amazing people growing this better food? 

These and many other questions are what we will be exploring in our podcast, Tasting Terroir. 

Hosts Dr. Jill Clapperton, a soil health scientist, and plant physiologist, and Sara Harper, a regenerative agriculture policy expert and founder of the online community Grounded Growth will introduce you to the science and practice of finding the flavorful advantages of food grown in healthy soil.

This project is made possible by listeners who become patrons of our work on Patreon.  Patrons gain access to full-length interviews and have the ability to submit questions for us to answer on the podcast.

Click here to learn more and support our work!

Rhizoterra Inc is an international food security consulting company that provides expert guidance for creating healthy soils that yield tasty and nutrient-dense foods. Owner & scientist, Dr. Jill Clapperton, and Rhizoterra work together with producers and food companies to regenerate the biological and environmental integrity of the land.

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