Understanding Rhizophagy: How Plants Eat Soil Microbes
Introduction
If you haven’t heard the word rhizophagy, you’re not alone. Before working at NutriSoil, I hadn’t either. And if you’re anything like me, it’s easy to get tangled in similar terms like rhizome, rhizosphere and rhizobacterium.
But once you understand the rhizophagy cycle, it unlocks a whole new appreciation for soil microbiology. You’ll never look at microbes the same way again.
Rhizo = root. Phagy = eating. Rhizophagy = plants eating microbes.1
Rhizophagy in a Nutshell
For decades, farming systems have focused on plants absorbing nutrients directly from soil through their roots. Rhizophagy adds another layer: plants accessing nutrients by digesting microbes.
In the rhizophagy cycle, microbes such as bacteria and fungi enter plant root cells, lose their cell walls, release their nutrients to the plant, and are then expelled back into the soil to rebuild themselves and start again.
It’s a nutrient‑delivery loop that nature perfected long before fertiliser was invented.
Meet the Microbes Behind the Magic
The microbes involved in rhizophagy are called endophytes—beneficial bacteria and fungi that live inside plants for part of their life cycle. Endophytes enhance plant growth, improve nutrient uptake, and increase resilience.2
All of them originate from soil organic matter.1
When we apply chemical fertilisers, only 30% – 40% of the nutrients actually make it into plant cells. Plants evolved the rhizophagy cycle to extract nutrients from microbes instead, a process that delivers nutrients with almost 100% efficiency.1
The process is explained brilliantly by Dr James White in this YouTube video by iCow https://www.youtube.com/watch?v=dhrssLEylu4
The Rhizophagy Process
Plants Produce Exudates
- During photosynthesis, plants release sugars, amino acids, secondary metabolites, fatty acids and organic acids into the soil, these are called exudates.
- These exudates stimulate microbial activity and attract beneficial microbes to the root tip.
Microbes Enter the Root
- Microbes move into the plant at the root tip and enter plant root cells.
Microbes Lose Their Cell Wall
- Inside the plant cell, microbes are exposed to reactive oxygen species (ROS), molecules that strip their cell wall.
- Nutrients from the microbial cell wall are absorbed by the plant.
Microbes Are Expelled
- Microbial activity triggers root hair elongation (root hairs cannot grow without microbes).1
- The now nutrient‑depleted microbes are expelled out through the root hairs and back into the soil.
Rinse and Repeat
- Once back in the soil, microbes rebuild their cell walls using nutrients from organic matter.
- They multiply and return to the root tip, ready to deliver nutrients again.
Benefits of Rhizophagy
- Microbes deliver organic, plant‑available nutrients directly into plant cells.
- Stimulates root hair development, improving water and nutrient uptake.
- Microbes produce hormones that support stronger plant growth.
- Increases plant antioxidant levels, boosting tolerance to drought, salinity and pests.
- Expelled endophytes compete with pathogens, improving plant resilience.
- Compounds produced during rhizophagy deter insects and pests.
- Each plant species cultivates its own microbial community, helping reduce weed pressure.3
What Reduces Rhizophagy?
Certain farming practices can interrupt the cycle:
Excessive tillage that destroys microbial habitats and fungal networks.
Overuse of synthetic fertilisers that suppress microbial activity.
- Fungicides and herbicides that harm beneficial microbes.
The NutriSoil Approach
We’re not suggesting farmers throw out every conventional tool. Rebuilding soil biology takes time, and no one can afford to go broke waiting for soil function to return.
Instead, here’s how you can support the rhizophagy cycle while keeping your system productive:
- Inoculate seeds with biology to build a microbial community around the seed.
- Use a bio‑stimulant like NutriSoil Biological Solution to increase photosynthesis and deliver microbes to the plant. These microbes will help fix Nitrogen, produce growth hormones that trigger the plants immune system
- Mix nutrients with a bio‑stimulant to improve nutrient absorption and microbial nutrient‑loading.
- Apply essential macro and micronutrients based on soil and sap testing.
- Keep living roots in the soil using cover crops (where you can) to feed your soil microbes all year round.
- Minimise chemical use and buffer necessary sprays with humic and fulvic acids or NutriSoil.
- Reduce synthetic fertilisers where possible to avoid suppressing microbial activity.
- Prioritise calcium, essential for root growth and development.
Take‑Home Message
Rhizophagy is a natural process in which microbes are attracted to plant exudates, enter the root tip, release nutrients within the plant, and then return to the soil to rebuild themselves. This cycle depends on photosynthesis, which means it depends on green, growing plants.
NutriSoil Biological Solution and NutriSoil Castings are powerful partners in supporting this process.
- NutriSoil Biological Solution provides diverse living and dormant microbes, complex compounds, humic and fulvic acids, amino acids, and signalling molecules that support plant growth. Used as a buffer with herbicides, NutriSoil helps plants recover from selective herbicide stress.
- NutriSoil Castings build and feed soil microbial populations and can be used as a soil amendment or compost extract.
Incorporating NutriSoil into your farming program is a practical first step toward harnessing a process nature has refined over hundreds of millions of years, a process powered by the humble soil microbe.
Two great YouTube videos explaining this process can be found in the references below.
REFERENCES
- James White – Rhizophagy, Seeds and Food Security
https://www.youtube.com/watch?v=dhrssLEylu4
- Endophytes: A Treasure House of Bioactive Compounds of Medicinal Importance – https://pmc.ncbi.nlm.nih.gov/articles/PMC5041141/
- Agresol Summary Rhizophagy – https://agresol.com.au/dr-james-whites-rhizophagy-cycle/
