Where There's Smoke, There's Money

Hey, Hannatu here 👋

Every harvest season, farmers around the world face the same question: what do you do with crop residue?

In wealthier agricultural economies, crop residue gets tilled back into the soil, composted, or fed into industrial processing chains. 

But across much of Africa, the answer is simpler: burn it.

Maize stalks, rice husks, cassava stems. All of it burns.

The smoke that follows blackens skies, chokes nearby communities, and releases millions of tons of CO₂ into the atmosphere each year. 

What could have been a resource becomes a liability and a health hazard.

But here's the question a growing number of African entrepreneurs are asking: what if that same waste could make farmers millions?

A handful of startups across the continent are doing exactly that. 

They are converting agricultural residue into biochar, a charcoal-like substance that separates carbon for centuries, rebuilds depleted soils, and opens up lucrative new income streams for the smallholder farmers who produce it.

Fertiliser. Carbon credit. Waste solution. All in one crumbly black product.

But to understand why this crumbly black substance matters so much, you first have to understand the scale of the problem it's trying to fix.

African farmers produce roughly 120 million tons of agricultural waste every year. 

Most of it is burned in open fields because it's the easiest method of disposal. 

At the same time, Africa's soils are degrading. 

Soil degradation costs the continent an estimated $68 billion yearly in lost agricultural productivity. 

Farmers know synthetic fertilisers could help, but prices have doubled since 2020, putting them out of reach for most smallholders.

The result is a vicious cycle. 

Poor soil yields less, so farmers can't afford fertiliser to improve it, and crop residues that could enrich the soil get burned instead. 

And in turn, the land gets worse every season.

Breaking that cycle requires something that can do three jobs at once.

Biochar, it turns out, does all three.

Biochar is agricultural waste heated in a low-oxygen environment through a process called pyrolysis. 

The heat breaks down organic material into stable carbon that can remain in soil for hundreds of years. 

Unlike compost, which decomposes, biochar doesn't break down. It's a permanent soil investment.

The benefits are measurable. 

Biochar improves soil water retention by up to 18%, which matters enormously in drought-prone regions. 

It increases fertiliser efficiency by 15-30%, meaning farmers need less synthetic fertiliser to get the same results. 

It reduces nitrogen leaching by up to 60%, keeping nutrients in the soil longer instead of washing away.

Each ton of biochar sequesters approximately 3 tons of CO2 equivalent. 

That carbon stays locked in the soil instead of floating in the atmosphere. 

And because biochar improves soil pH, it makes acidic soils more productive without expensive lime treatments.

The science is compelling. 

But science alone doesn't move farmers. Money does. 

And the economics of biochar are where things get truly interesting.

The global biochar market was valued at $2.8 billion in 2023. 

By 2033, it’s projected to reach $28.9 billion. 

Africa's agricultural waste could theoretically produce 200 million tons of biochar annually, which at current market prices represents a $100-300 billion opportunity.

Africa's synthetic fertiliser market is worth $8 billion. 

If biochar captured just 10-15% by supplementing or partially replacing synthetics, that's another billion-dollar market.

Field trials in Kenya show 25-40% yield increases when biochar is combined with reduced synthetic fertiliser, proving the substitution works agronomically.

The carbon credit market adds another revenue layer. 

Companies like Microsoft, Shopify, and Stripe are actively seeking biochar projects for their carbon offset portfolios. 

Farmers who produce biochar can sell the carbon credits, creating income from waste they used to burn for free.

The numbers exist on paper. 

But startups are trying to make them real on the ground.

And unlike poultry meat, the domestic market absorbs nearly all production.

Bio-Logical operates in Kenya, focusing on rice husks and maize stalks: two of the country's most abundant agricultural wastes. 

They've developed low-cost pyrolysis kilns that smallholder farmer cooperatives can operate without massive capital investment.

Their model is circular. 

They produce biochar from agricultural waste, create fertiliser from it, then supply that fertiliser back to the farmers who provided the waste. 

Farmers get better soil, reduce synthetic fertiliser dependence, and earn income from crop residues they used to burn.

Releaf Earth works across multiple African countries, targeting larger-scale operations. They partner with agricultural processors who generate waste at centralised locations: rice mills, maize processing facilities, cassava processing plants. 

The concentrated waste makes collection easier and production more efficient.

Both companies are navigating the same fundamental challenge: convincing farmers that waste has value. 

For generations, burning crop residues has been free and easy. 

Collecting, storing, and transporting that waste to a biochar facility requires behaviour change, and behaviour change requires proof that the effort pays off.

The model works in theory, and increasingly in practice. 

But scaling it means confronting obstacles that no amount of good science easily solves.

Pyrolysis equipment costs between $20,000 and $100,000, depending on scale. 

For smallholder cooperatives, that's expensive without grants or concessional financing. Even if farmers want to produce biochar, accessing the capital to start is nearly impossible through traditional banks.

Awareness is another problem. 

Most farmers have never heard of biochar. 

They don't know it exists, don't understand how it works, and haven't seen proof that it improves yields. Without demonstration plots and peer-to-peer learning, adoption stays slow.

Quality control is tricky. 

Biochar effectiveness depends on feedstock type and production temperature. 

Rice husk biochar behaves differently from maize stalk biochar. 

If the production temperature is too low, the carbon isn't stable. If it's too high, nutrients burn off. Standardising production without expensive testing equipment is difficult.

Still, the barriers exist alongside evidence that's hard to ignore. 

This evidence speaks directly to what farmers care about most: what actually grows

Field trials matter more than theory. 

In Kenya, farmers who applied biochar combined with reduced synthetic fertiliser saw yield increases of 25-40%. 

Water retention improvements are especially compelling in regions facing erratic rainfall. 

When biochar helps soil hold 18% more water, crops survive dry spells that would otherwise kill them. 

For farmers who've lost entire harvests to drought, that resilience is worth paying for.

Reducing nitrogen leaching by 60% means the fertiliser farmers apply stays in the soil longer. This increases fertiliser effectiveness and reduces the amount needed per season. 

For farmers spending half their income on inputs, cutting fertiliser costs by even 20% changes their entire economic equation.

Biochar also improves soil pH, making acidic soils more productive. In regions where soil acidity limits crop growth, biochar provides a cheaper alternative to lime treatments. 

Farmers see results in the first season, which builds trust faster than long-term carbon sequestration promises.

But the fastest way to scale any agricultural practice in Africa is when governments push from the top down. Fortunately, that's starting to happen.

Kenya's Ministry of Agriculture is exploring biochar as part of its climate-smart agriculture strategy. 

If the government endorses biochar in official extension services, adoption will accelerate because farmers trust government agronomists more than they trust startups.

The African Development Bank has a $50 million facility for agricultural climate adaptation projects. 

Biochar qualifies because it simultaneously addresses soil degradation, carbon sequestration, and fertiliser cost reduction. 

Startups that can demonstrate impact at scale could access this financing.

Nigeria's agricultural waste management policy may mandate alternatives to open burning by 2026. 

If enforced, this would create immediate demand for biochar production as farmers and processors scramble for legal waste disposal options. That regulatory push could catalyse the entire industry overnight.

Put the agronomics, the economics, and the policy momentum together, and a bigger picture starts to emerge.

If just 10% of Africa's agricultural waste became biochar, it would sequester roughly 60 million tons of CO2 annually. 

To sequester means to set apart, segregate, or isolate something.

That's equivalent to taking 13 million cars off the road. 

Not as a one-time offset, but permanently, because the carbon stays in the soil for centuries.

Simultaneously, biochar would improve soil health on millions of hectares. 

Yields would increase, fertiliser costs would drop, water retention would improve, and soil degradation would slow. 

The compounding effects over a decade could fundamentally alter African agriculture's productivity trajectory.

Farmers would gain new income streams from the waste they currently burn. 

Instead of being a disposal problem, crop residues would become cash crops. 

Cooperatives could negotiate bulk sales to biochar producers, creating collective bargaining power that individual smallholders lack.

Africa would reduce dependence on imported synthetic fertilisers. 

Every ton of biochar that supplements or replaces synthetics is a foreign exchange saved. 

For countries struggling with forex shortages, reducing fertiliser import bills by even 10% frees up capital for other investments.

If you're a farmer, what other alternatives to burning or disposal do you think are better?

👉🏾Tell me here.

Cheers,

P.S We’re taking off for the long break today, so you won’t get a roundup this week. We’ll be back next Tuesday.