#DecodeAgri24: SOC, Soil Health & The Metrics

Minimalist black background with white sans-serif text reading "#DecodeAgri24: SOC, Soil Health & The Metrics." A small circular logo is in the top-left corner and a vertical handle, @random.whys, is in the bottom-right.
8–12 minutes

We have spent years on optimizing the things that happens above the soil.

Seeds, irrigation, fertilizers, pest management, pre and post harvest techniques. The modern and current techniques also revolves around what can we see, photograph and measure based on the metrics at the surface.

Soil beneath runs a different story. The interaction of microbes, CO2, the availability of nutrients are often not looked. Despite the decades of research and development is no way near to observe the real time, in open field at the scale of a working farm.

This piece of blog will try to cover the gap that exists and what can be measured in theory. I am not sure quite whether any startups or company is doing it.

Why real time measurement matters ?

The traditional soil kits (Soilometer, MicroBiometer and others) and the lab analysis doesn’t cover the actual picture of soil health underneath. The former predicts at the real time yet the details are missed and with the later part, reports are received after a week or more. The core issue that needs to be addressed are lost in translation.

This is the problem that live root-zone monitoring is beginning to address. There are startups such as Proximal SoilSens, FASAL, Agri Inverse (Live root measurements) has built sensors that sit near the root zone and track moisture, temperature, and electrical conductivity. For polyhouse and precision horticulture systems, this is a meaningful upgrade. The farmers have a live feed of physical and chemical conditions at the root. It also infers that Soil Organic Carbon not by measuring it directly, but by reading nutrient ion availability in the soil solution. Higher organic carbon generally correlates with higher nutrient availability and richer EC signatures.

But here is where the nuance gets missed.

Is phosphorus low because SOC is genuinely depleted? Or because the microbial community that unlocks phosphorus is suppressed? Or because microbial community altered? Or because moisture stress collapsed the fungal hypae network?

The reading looks identical in all four cases. But the intervention and scenario is completely different in each one. Maybe a chemical or biological problem.

That distinction determines the entire outcome. Incase of chemical farming systems, where inputs are standardized and optimized and the feedback loop is relatively managed, this gap is manageable. For regenerative and natural farming systems, where the biology is at the center, it might appear as fundamental blind spot.

The live feed of biological activity is something that does not yet exist at field scale but need of the hour.

The technology that make this (Theory)

Based on my understand and with help of claude, this could work. I am not sure this exist already. As far as I know, It is yet to be developed as it seems quite impossible or looks good more on paper than on fields.

A Microbial Fuel Cell (MFC) is not a new concept. It has been used in wastewater treatment for decades (mostly in developed countries). The underlying science is that certain soil bacteria called exoelectrogens, release electrons as a metabolic byproduct when they consume Soil Organic Carbon.

The signal is directly interpretable. High current means microbial communities are actively feeding and nutrients are being unlocked, biological processes are running. Low current means the opposite. The soil is metabolically stagnant, regardless of what the NPK reading says on paper.

Companies like Bactery are now attempting to bring this technology out of wastewater management and into agricultural applications. Like disposable soil sensors, power IoTs. The engineering challenge is real and quite difficult. Open field conditions are noisier and more variable than controlled treatment plants.

However, an MFC electrode alone is not sufficient. Electron flow measures and indicate metabolic rate. It does not tell you which micro organisms are active. Whether the activity is beneficial microbes or pathological, or the ratio of Bacteria to Fungi is not covered here. MicroBiometer covers the later part but it doesn’t address the former one. That’s why we need a stack of layers on top.

Building the sensing stack

CO2 Flux Sensors:

The microbial decomposition of the organic matter produces CO2 as a direct byproduct. This could be interpreted for total microbial availability for beneficial microbes as the other produces methane, volatile compounds and others. Vaisala (GMP343) and Senseair (S88 / Sunrise) are better at capturing the same at a different price range.

Redox Potential (Eh) sensor

This sensor helps to measure whether the soil environment is oxidative or reductive. When soil is well-aerated, oxygen level is high and the redox value is high. The aerobic bacteria thrives, organic matter breaks down efficiently, and nutrients become plant-available. When soil is waterlogged or compacted, oxygen depletes and the redox value drops. The environment turns reductive, anaerobic bacteria take overs.

This matters for AE or NF. Bio inputs has lot of aerobic organisms (bacteria and fungi) that require an oxidative environment to establish and function. A redox sensor would catch this immediately.

MFC

The Microbial Fuel Cell electrode on the top of these and acts as biological signal becomes directly readable as electricity. High current means the soil is biologically alive and low current means the opposite. The metabolic activity has stopped/less, regardless of what the nutrient readings says.

All these together along with existing root zone sensors could give a comprehensive picture of soil health.

Who actually needs this & who doesn’t

This is where it gets interesting and the actual market segmentation happens. The current investment nor the segmentation is aligned.

Polyhouse and hydroponics systems do not need microbial sensing. Precision chemical farming in open fields are very limited. Synthetic fertilizers suppress or doesn’t enhance the microbial diversity. This production method/chain has already been removed from the equation.

Regenerative farming, natural farming, poly cropping or agroecology would benefit from this as the system revolves around the soil carbon. biological ratios, long term resilience. Since this helps in the biological monitoring and actuals usage of bio inputs such as Jeevamirutham and others.

This is why the most commercially attractive methods (controlled environments, precision horticulture) are also the least scientifically interesting ones. And it is why open-field regenerative soil monitoring remains largely unaddressed right now.

The policy contradiction

The Indian government is running/solving both sides of this equation simultaneously.

On one side, fertilizer subsidy of over ₹1.91 lakh crore (2025), supported by decades of soil testing infrastructure, input advisory systems, and increasingly precision farming tools. The measurement and optimization ecosystem for chemical agriculture is also getting advanced with AI and robotics.

On the other side, the National Mission on Natural Farming, certification and labels and various state-level missions zero budget natural farming programs all of which are scaling without any equivalent measurement infrastructure. True that, they are still in the infant stage.

The result is a structural asymmetry:

Chemical Farming: Spend ₹X on inputs → Measure soil NPK → Verify crop response → Adjust (Feedback loop exists)

Regenerative Farming: Spend ₹X on NMNF → Apply bio-inputs → ??? (Feedback loop is absent)

Programs that cannot demonstrate measurable outcomes/outputs cannot compete for sustained budget allocation. This is just an observation about institutional survival. Good programs die not from failure but from immeasurability. The sensor infrastructure for these is not just a scientific gap. More of policy and technology gap with direct consequences for whether these programs can scale.

The ecological cost

Water efficiency, pesticide reduction, quantity and quality are some of the problems that are genuinely tackled by the precision farming and other controlled environmental systems. But these systems are optimized for the happenings of within the boundaries or the walls. For eg, parthenocarpy, bumble bee boxes for pollination and more. The cost of replacing these ecological services with labor and technology are rarely counted in ROI. It is the direct price of having removed a biological service that open fields receive for free.

This is the broader pattern worth paying attention to. Every time a farm separate itself from the surrounding ecosystem whether through walls, monoculture, or synthetic inputs. it removes itself from the biological and ecological services that ecosystem was quietly providing.

The transition

It is important to be clear about what this blog is analyzing and is not arguing.

The shift toward controlled environment agriculture, precision farming, and input optimization is not reversible, nor should it be. These systems will feed growing urban populations, reduce post-harvest loss, and enable year-round horticulture that open fields cannot reliably provide. They are part of the future of Indian agriculture.

So is open-field polycropping. So is natural farming. So is the complex, diverse, difficult to quantify agroecological systems that have maintained soil health across centuries of Indian agriculture.

The transition between these systems will be gradual. Both will coexist and needs to exist for decades. That coexistence is not the problem here. The problem is that we are not managing it, we are allowing it to happen without instrumentation, and measurement infrastructure. This would let us understand what we are gaining and what we are losing in the long run.

What needs to be built?

Two parallel measurement infrastructures are required. Not as competition, but as complementary.

The first already exists in partial form. Sensor, IoT systems and upcoming robotics for precision and controlled environment agriculture. The gap here is extending that infrastructure to capture biological indicators such as soil microbial activity, predator-prey ratios not just physical and chemical parameters.

The second does not yet exist at meaningful scale. A biological monitoring layer for open-field regenerative systems. This includes the sensor stack as mentioned in the beginning of this blog, but ultimately points toward Biodiversity Activity Index that combines soil microbial flux, CO₂ respiration, nutrient availability for different crops at different depth, and plant diversity into a single, auditable metric.

This score will be helpful and may be that’s what these credible carbon credit market needs. It is what a regenerative certification system needs to mean/focus on.

The technology components to build it are available. The integration, the field validation, and the institutional will to invest in it are what is missing.

That asymmetry is not just a scientific inconvenience. It determines which system gets optimized, which gets funded, and which gets scaled. In the end, these questions needs to be addressed yet.

If the ecological services of open fields are genuinely invisible to people, when do we notice they’re gone?

And who decides when the measurement infrastructure for natural farming gets built? Market has no immediate/less incentive to, or the government that is already funding both sides of the equation without a way to read either?

Cheers

PS: Lets Remote Sensing in the upcoming ones.

Check out the similar posts: #DecodeAgri23: Farming, AI & The Missing Structure! & other Agri posts

Previous post: Feel Good Ones – #2

Follow on IG X for more!

If you like what you see and wish to support my work, then

Share your thoughts/suggestion at the comment section or mail at

randomwhyss[@]gmail[dot]com

Don’t miss out! Get notified about new blog posts straight to your inbox !

(No spam, pinky promise!)

Enter your mail to receive updates

Unknown's avatar

Author: Sunandhini R

Curious Learner!

Leave a comment

Discover more from Random Whys

Subscribe now to keep reading and get access to the full archive.

Continue reading