BhuCarbon
Rows of young crop seedlings running to the horizon across dark tilled soil at dawn, a tractor working a ridge on the left and a river winding through the fields on the right.

Permanent carbon removal that begins as better soil.

  1. A tractor-drawn hopper spreading dark crushed basalt in an arc across a field of young maize seedlings at first light, grains scattering over the tilled soil between the rows.
    01

    Basalt is spread

    Crushed silicate rock, applied at agronomic rates on the calendar farmers already work to.

  2. Ground-level view of rain running between rows of maize seedlings, pooling around wet basalt fragments in the soil. Small CO₂ labels and a carbonic-acid molecular diagram are overlaid on the water.
    02

    Rain dissolves it

    Rainwater carrying atmospheric CO₂ forms a weak acid and attacks the rock grains.

  3. A cutaway soil profile beneath a row of maize, showing water percolating down past roots and angular basalt fragments. Overlaid arrows labelled HCO₃⁻ trace the dissolved bicarbonate moving downward through the horizon.
    03

    Carbon becomes bicarbonate

    The reaction converts CO₂ into dissolved bicarbonate — no longer a gas, no longer in the air.

  4. Aerial view of a river meandering through a patchwork of cropped and harvested fields towards the sea on the horizon. Overlaid arrows labelled HCO₃⁻ follow the channel downstream to the coast.
    04

    Rivers carry it to the ocean

    Where it is stable on a timescale of tens of thousands of years. This is the durability claim.

    The durability claim

    Dissolved bicarbonate reaching the ocean is stable for tens of thousands of years. That is the removal — not the rock, and not the spreading.

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What we do

Three things have to be right at once.

  • The rock

    Basalt, sourced close to the field

    Crushed silicate rock from quarries near the districts we work in. Every lot is assayed for composition before it leaves, and haulage is kept short — long transport spends the removal before it is earned.

  • The field

    Applied on the farmer’s calendar

    Spread at agronomic rates, in the window that already exists in the cropping cycle. If it does not fit the season a farmer actually works to, it does not get applied, and nothing else in this list matters.

  • The measurement

    Sampled before, during and after

    A georeferenced multi-depth baseline is taken before any rock is applied, and the same plots are resampled across seasons. Removal is measured against that record, not modelled in place of it.

The mechanism

Enhanced rock weathering, in four steps.

Silicate rock has been pulling CO₂ out of the atmosphere for as long as there has been rain. It is slow — geologically slow. Crushing the rock increases its surface area by orders of magnitude, and spreading it on cultivated soil puts it where water, acids and roots are already at work. The chemistry is unchanged. Only the rate is.

  1. 01

    Basalt is spread

    Finely crushed silicate rock is applied to farmland at agronomic rates, using the equipment and calendar farmers already work to.

  2. 02

    Rain dissolves it

    Rainwater carrying dissolved atmospheric CO₂ forms a weak carbonic acid. It attacks the rock grains, releasing calcium and magnesium.

  3. 03

    Carbon becomes bicarbonate

    The reaction converts CO₂ into dissolved bicarbonate — a stable, aqueous form, no longer a gas and no longer in the atmosphere.

  4. 04

    Rivers carry it to the ocean

    Bicarbonate drains to the sea, where it is stable on a timescale of tens of thousands of years. This is the durability claim.

The reaction CaSiO3 + 2CO2 + H2O yields Ca2+ + 2HCO3− + SiO2

Where we work

India is not one soil, and the difference decides everything.

The rate at which basalt dissolves, the size of the agronomic benefit, and how hard the removal is to measure all change with the ground beneath it. An acidic lateritic soil in Chhattisgarh and a calcareous alluvial soil in Bihar are not variations on one deployment — they are different problems that happen to share a feedstock.

We hold a separate interpretation model per agro-climatic zone, written and owned by the science team. Its full contents, including the zones where enhanced rock weathering is a hard case for us, are on the science page.

Read the zone-by-zone assessment

  • Red & lateritic Chhattisgarh · Odisha · Jharkhand · eastern MP
  • Indo-Gangetic alluvial Uttar Pradesh · Bihar · Punjab · Haryana
  • Deccan Vertisols Maharashtra · Madhya Pradesh · Telangana
  • North-eastern & Himalayan foothills Assam · Meghalaya · sub-Himalayan belt
  • Coastal & saline Coastal Andhra · Gujarat · Sundarbans margin

How we measure

What we sample, and why each one is on the list.

Enhanced rock weathering is only as good as the evidence that it happened. This is the panel every sample runs through — the farmer-facing figures and the carbon accounting come from the same soil.

Baseline
0–15 cm · 15–30 cm
Multi-depth and georeferenced, taken before a single tonne of rock is applied.
Total elemental
XRF
Whole-rock and whole-soil composition, not just the plant-available fraction.
Immobile tracer
Ti · Zr · Nb
Elements that do not weather, used as the denominator for depletion mass balance.
Exchange chemistry
CEC · Ca · Mg · Na · K
Base cations released by dissolution, and where they end up.
Conversion basis
Bulk density · texture
What turns a concentration into tonnes per hectare. Skipping it is how estimates go silently wrong.
Safety panel
Ni · Cr · V
Trace metals carried by basalt. A food-safety exposure, monitored as one.

For the farmer

The soil test is the product, not a by-product.

A farmer who takes part gets a soil health card in the format they already know, in Hindi, every season — and, unlike the card they receive today, one they can compare against last year's.

Returned to the farmer

Soil Health Card

Laid out in the Government of India format farmers already receive, in Hindi, with the season-on-season comparison the government card does not give them.

pH
Acidity or alkalinity
EC
Salinity
OC
Organic carbon
N · P · K
Available macronutrients
S
Sulphur
Zn · Fe · Cu · Mn · B
Micronutrients

Same sample, carbon accounting

MRV panel

The additional analytes that turn a soil test into a removal estimate. Not shown on the farmer's card because it would not help them — but published here, because it should help you.

CEC + base cations
Ca, Mg, Na, K on the exchange complex
Soil inorganic carbon
Carbonate content and background
XRF total elemental
Whole-soil composition
Ti · Zr · Nb
Immobile tracers for mass balance
Bulk density · texture
Concentration to tonnes per hectare
Ni · Cr · V
Trace metal safety panel

Where we stand

We have not issued a carbon credit yet.

You will not find tonnage counters, registry badges or a wall of buyer logos on this site, because we have not earned them. What exists today is a measurement protocol, a per-zone interpretation model, and field deployment getting under way.

When there are numbers, they will arrive with the working shown: which plots, which geometry version, which model run, and what the uncertainty was. Until then, the method is the claim.

Read the method Talk to us