What we don't claim

Biochar attracts overclaiming. The underlying science is real and in places remarkable, which is exactly what makes it easy to stretch. Most of the stretching isn't dishonest. It is usually one study carried further than it can bear.

The effect is that the sector gets harder to evaluate, and a buyer who has been burned once discounts everyone. So here is where we think the line sits, including for our own work.

On yields

We will not tell you biochar will increase your yield by a specific percentage. The effect is real in the right conditions. The size of it depends almost entirely on what those conditions are.

The large responses in the literature come predominantly from degraded, acidic, sandy, low-organic-matter soils, where almost any intervention helps. On fertile, well-managed soil the response is frequently small, and sometimes nothing at all. Quoting a headline figure from a weathered tropical oxisol at someone farming a different soil is marketing with a citation attached.

What we will do is tell you which category we think your situation falls into, and design a trial that answers the question for your soil and your crop.

On permanence

We will not quote a single number of years. Biochar carbon is durable, and that durability is the reason it qualifies as carbon removal. But "biochar lasts a thousand years" takes one figure and applies it to every material anyone has ever made.

Stability depends on how the char was made, principally peak temperature and the degree of aromatic condensation that results. Certification schemes use the hydrogen-to-organic-carbon ratio as their proxy precisely because material varies this much. Char from the same feedstock at two different temperatures has measurably different permanence, and only one of the two may clear a given threshold.

A producer quoting a permanence figure without reference to their own material's measured properties is quoting somebody else's char.

On what biochar does in soil

The mechanisms are well established: porous structure holds water, high surface area and charge reduce nutrient leaching, most biochars are alkaline and can correct acidity, and the pore structure provides microbial habitat. None of that is in dispute.

What we won't say:

• That it works everywhere. On soil that is already fertile and well structured, the case is much weaker.
• That it works immediately. Raw biochar can tie up nitrogen in the first season while its surfaces fill. It is the commonest reason a first trial disappoints, and the fault is in the formulation, not the material.
• That more is better. Above some application rate the response flattens or reverses, and that rate differs by soil.
• That it replaces fertiliser. It changes how well applied nutrients are retained and made available, which is a narrower claim and a more defensible one.

On our own equipment

We are developing a pyrolysis machine with engineering partners. We are not publishing throughput, yield, uptime or cost-of-ownership figures for it, and we are not claiming it is better than the alternatives.

We have not measured it in the field against defined benchmarks. Until we have, any figure we published would be a projection dressed as a result. The first unit goes to a site of our own rather than to a customer for the same reason: the prototype risk should be ours to carry.

When there are numbers, we will say how they were measured and on what.

On carbon accounting

A tonne of biochar is not a tonne of CO₂ removed, and the conversion between them is not a constant. It depends on the carbon content of the specific material, on the stable fraction of that carbon, and on the emissions from production, transport and application, all of which have to come off the total.

Feedstock sourcing matters as much as the chemistry. Residue that would otherwise have decomposed or been burned is a real removal. Biomass grown, diverted or harvested for the purpose is a different calculation, and one that deserves scrutiny before anyone buys the credits.

On our own experience

We work on biochar facilities in Africa, currently in Kenya and Tanzania, and have done for years. We are not naming clients on this site, so you should treat that as an unevidenced statement until you have talked to us and tested it.

That is a more useful answer than a page of logos and vague numbers. Ask us the direct questions instead. What have you fixed, what went wrong on it, what could you not solve. Then judge the answers.

What we do claim

Narrower, and we will stand behind all of it:

• We can diagnose why a pyrolysis facility is underperforming, and we will tell you if we cannot.
• We can keep a plant running, with engineers based in the region rather than mobilised from abroad.
• We can characterise biochar and design a formulation and trial programme appropriate to a specific crop and soil.
• We can build the evidence a distributor or regulator will accept, or tell you honestly that the evidence is not there yet.
• We will report what the measurements say, including when they are inconvenient for us.

Why publish this

Partly because the alternative erodes trust in a technology that deserves better. Mostly because of who we are trying to reach: people who have already bought something that did not perform, and who are now, reasonably, sceptical of the next person through the door.

If you are one of them, the useful thing we can offer is not a stronger claim. It is a narrower one that turns out to be true.