The magic of soil

James Harper: So about a year ago, February, 2023, I stepped outside my apartment building in Berlin and crunched snow underneath. In the pitch dark, I find one of those rental scooters. I shiver like crazy as I make my way to a train station, which takes me to an airport, where I get on a flight, and then, 12 hours later, I step off the plane onto hot tarmac and breathe in this thick tropical air. I was in Honduras. Smack bang in the middle of Central America. The next morning, we're on a minibus. And we're driving six hours west. Our destination? The small town of Copan Ruinas, right in the top left corner of Honduras, and I was traveling there to attend Let's Talk Coffee, an annual gathering of forward-thinking coffee farmers, roasters, and other coffee professionals from across the world organized by Sustainable Harvest. They are the sponsor of this episode and a leading importer of organic fairtrade specialty coffee.

At a conference center, just a stone's throw away from some spectacular Mayan ruins, I found myself transfixed watching presentations from leading thinkers in the regenerative organic coffee movement. Every lunchtime we'd walk outside and pass the pair of rescued macaws with beautiful red glistening feathers and while digging into delicious local food like baked fish and sour orange, I spoke with farmers from across the region and was brought up to speed with what was happening in their coffee farming world.

And at Let's Talk Coffee, I was asked to moderate a panel on something that I knew almost nothing about: organic coffee farming.

Now look, almost my entire life I have lived in cities, and when I think about where my food comes from, well, I might be on a train going from one city to another, I look out the window and see fields of wheat, fields of potatoes, fields of hay, and my conception of how farming works is, well, you have some land, you put plants in the soil, you feed them fertilizer, nutrition, you make sure they get enough water, you spray them with pesticides to stop the insects eating them, and when it comes to harvest, you collect the crops, and you do it all over again. But then, I end up on this panel at Let's Talk Coffee, and I meet one person in particular who just flips my understanding of how agriculture works a full 180.

Lalo Perez Varona - Buna: I'm Lalo Perez. I work for a consulting agency and we assist any producer who's interested in the transition from conventional, chemical-based agriculture over to biological agriculture.

James Harper: So on one of those hot afternoons as the sun is beating down,

I'm with Lalo alongside the river that snakes past this convention center, I ask him to retell the story that he told on stage at Let's Talk Coffee, a story that shows why, the way most of the world grows food, the way that I see food being produced when I look outside the train window, could lead to a global crisis.

So a few years ago, Lalo gets a call from a large coffee farmer in Guatemala, who is ringing him desperate.

Lalo Perez Varona - Buna: I mean, this was kind of a, it'll make me cry a little bit, but yesterday he told me I had lost hope, I was ready to sell my business.

James Harper: This Guatemalan farmer, who I have chosen to keep anonymous because this is not a flattering story, but he is representative of how the majority of coffee is grown. So he has thousands of trees in neat rows going up and down his mountain slopes, all sitting in the sun. He was managing his coffee farm, the conventional way, textbook. He tries to maximize how many coffee cherries his trees produce by giving them a lot of chemical fertilizer. If he sees a fungus developing on one of the leaves, he would spray them all with this chemical fungicide. When he sees an insect, he would cover the plants in chemical insecticides. And for many years, he gets a good harvest and he runs a successful coffee business. But, recently, things have been going very, very wrong.

Lalo Perez Varona - Buna: To maintain an aesthetically healthy plantation – a plantation that looks good, looks green, it's vigorous; to maintain that standard he was having to use higher and higher inputs: herbicides, fungicides, fertilizers. And the increase in inputs was not translating to an increase in productivity anymore. it was not only stagnant, but declining. Productivity was declining.

James Harper: This farmer had a serious problem: his harvest was getting smaller and smaller. And, in the world of conventional agriculture, when this happens, well, one solution is to give more chemical fertilizer to the plants.

But no matter how many little blue pellets he threw in the ground (chemical fertilizer), his harvest kept getting smaller and smaller. And the very strange thing is that on the surface. His plants looked green, vigorous, but they were ravaged by disease. Like Roya, a fungal disease that attacks a coffee plant's leaves. It kills the leaf and stops the plant getting energy from the sun.

Lalo Perez Varona - Buna: So in essence, he realized, “I'm spending a lot of money to keep my plants looking nice, but they're not healthy because they can't resist pathogens,” for example.

James Harper: In short, as a business, this farm was dying because the farmer couldn't grow coffee profitably anymore. And this is far from an isolated case: the United Nations has been warning us about this for years.

And for example one of the other panelists I talked to at Let's Talk Coffee…

Tommie Hooft van Huysduynen: I am Tommy. I'm the CEO and co-founder at Protein.

James Harper: He runs an organic composting solution for Ugandan coffee farmers... and Tommy paraphrased what the United Nations Food and Agricultural Organization's Deputy Director General said almost 10 years ago.

Tommie Hooft van Huysduynen: You must have heard that we only have 60 harvests left if we continue the way that we cultivate.

James Harper: The world's farming soils are only capable of offering us another 60 harvests. And that warning was given to us back in 2014. It's been almost 10 years. So by that estimate, we now probably have only 50 harvests left.

And when I first heard that, I was shocked! My mind raced forward to a world of higher food prices, widespread famines, protests, civil wars, and so much suffering, because we may not be able to grow enough food anymore. The heart of the problem is that there has been a steady decline in soil quality since the Green Revolution.

The Green Revolution was a moment after the Second World War when a very powerful new fertilizer made from nitrogen on this industrial scale was sold to farmers across the world. This fertilizer supercharges global food production. It's one of the reasons that the population of our world has blown up from two and a half billion in the 50s to 8 billion just recently.

Industrially produced nitrogen based fertilizers have enabled us humans to more than triple in size in just 70 years. The lifetime of my own parents.

But this new method of farming, what is now considered conventional farming, has been terrible for the health of our soils.

And beyond the existential issue of the world running out of food because our soils are so degraded, this issue is also intimately connected with climate change because industrially produced nitrogen based fertilizers have a huge CO2 footprint, with some estimates suggesting it's responsible for 5 percent of the world's greenhouse gas emissions every year.

So this is where conventional agrochemical farming has got us. It enables us to grow tremendously, but if we continue down this path, critics of conventional farming say, we are going to regret it and now an alternative to conventional agrochemical farming is organic farming. And that's what I'm going to show you in this episode.

I'm going to show you how organic coffee farming actually works in this corner of Honduras. But organic coffee farming, it's not easy. And there are many reasons why a coffee farmer wouldn't want to do it. And that's what I'm going to explore in the next episode.

James Harper: I'm James Harper, and this is The Science of Coffee, a spin-off series from my documentary coffee podcast Filter Stories, and a journey into coffee's hidden microscopic secrets.

Okay. Organic agriculture. I've come across it so many times before as a consumer. My brother's really into it. Beyond the basic philosophy, you know, no chemical fertilizer or pesticides. I didn't really understand what it was doing to the soil. But I had that aha moment when I was at Let's Talk Coffee.

Lalo Perez Varona - Buna: Understanding soil biology is not, it's just not simple. It's extremely complex and dynamic.

James Harper: I was by the river, speaking with Lalo Perez, and he told me the story of when he visited that Guatemalan farmer who rang him up desperate. That's when I was like, wow, this is how bad soils can get in a conventional coffee farm using agrochemicals. So here's what happened: Lalo, who's based in Mexico, traveled south to Guatemala and visited this farmer. Now the issue was that no matter how many blue pellets of chemical fertilizer this farmer threw with his trees, they were producing less and less coffee cherries. When Lalo looked at the trees, they seemed fine, lush, and green.

But he knew that was only half the story. The other half of the story was underground.

Lalo Perez Varona - Buna: It's quite simple to realize what's going on in a farm by looking at the soil, if you know what to look for.

James Harper: Lalo wanted to inspect the roots…

Lalo Perez Varona - Buna: So the first thing we did with him was walk around and look at soil and I asked him, “Here we have a mission for today: we're gonna look for one fungal, hyphae.”

It looks like a really thin floss, like a filament.

James Harper: Fungal hyphae are organisms, tiny tiny organisms that attach themselves to the roots of plants. They connect to other fungal hyphae and they create this network between plants. They're one of the plant world's best friends – they form this symbiotic relationship where they help with nutrient uptake. They help to create a better soil structure.

Lalo Perez Varona - Buna: If you went to a forest, they're everywhere. It doesn't matter where you look, they're everywhere. They're absolutely abundant. They're a part of a biologically functioning ecosystem.

James Harper: And when Lalo was walking around the forest that surrounded this coffee farm, he found loads of them.

Lalo Perez Varona - Buna: And wherever we looked there was fungi, you know?

James Harper: He got down on his hands and knees and scraped away at the dirt at the base of these plants in this forest, and he would find the white filament strands connected to the roots. The fungal hyphae. The forest was very healthy. It was a well functioning ecosystem, but when Lalo stepped across the fence and walked just a couple of meters into this coffee farm…

Lalo Perez Varona - Buna: And we looked, we searched under the soil, we went everywhere. We didn't find a single, not one fungal hyphae. We found nothing.

James Harper: The roots of these coffee trees were bare, not a single white filament strand, and yet just a few meters over the fence in the forest, every tree root is full of them.

And Lalo determined that these coffee trees didn't have fungal hyphae because they were being grown conventionally with a lot of agrochemicals.

Lalo Perez Varona - Buna: So the excess of chemicals and herbicides and fungicides that killed the fungi were all contributing to decreasing the soil diversity.

James Harper: This is the moment I realized that soil diversity matters. These Guatemalan coffee farmers' trees were producing less and less every year because down in their root system, there just wasn't enough complexity of life, of microorganisms.

It was missing out on certain micronutrients. It wasn't able to efficiently digest the blue pellets of chemical fertilizer that were being thrown at it. We'll come back to this farm. But now I want to take you to the coffee farm where I saw for the first time what really good soil diversity looks like.

So, after the Let's Talk Coffee gathering in Copan Ruinas, in the top left corner of Honduras, I hopped in a jeep with Alison Strieker who was Sustainable Harvest's brand assurance manager at the time. And she very graciously accompanied me for a couple of days, more than anything else just to help me on what I suspected would be quite technical pieces of Spanish. So we headed South, our Jeep snaking up and down the mountains of Honduras, and once we got half way down the country, not far from the border with El Salvador, we pulled into the driveway of one of the leading organic coffee farmers in this region.

I get out of the car next to this enormous black rotting pile of muck, and meet Don Fedorfino Dominguez. He's known in the community as Don Rufino. And the day I meet him, he's wearing this heavy blue cotton shirt, ballpoint pen in his breast pocket. And I thought to myself, yeah, he could be maybe early, mid fifties. He didn't have very many gray hairs coming through underneath his baseball cap. Turns out though, he's almost 70. And Don Rufino has a reputation in the area for growing very good specialty coffee, scoring 84, 85, sometimes even up to 87 points. For the non-experts listening, very delicious coffees.

James Harper: I followed Don Rufino as he took me into his bungalow. I walk past a small TV on the wall, and then I find myself in his rustic kitchen.

His wife is there catching up with an old neighbor, and Don Rufino is stood to the side by an old refrigerator. I get the impression that, you know, he's being polite, just helping the conversation along.

But I get a different side of him when we finish the small talk and we step outside into the farm that surrounds his house. That's the moment he springs to life. He walks me to the ginormous hole he has next to his house where he throws all his organic household waste to compost.

I feel like I'm with an excitable teenager. He just jumps right into the pit, he points to a little flower that's pushed its way past rotting banana peels and a mouldy mango. And tells me, “Look, look, this is a lemon.” He pushes the pot to dirt and earthworms, many little critters start scurrying around. This is living organic material, he tells me.

James Harper: We feed it to the plants, and it doesn't have a bad smell at all.

Don Rufino scopes up some of this rotting dirt and we stare at it. It is dense, thick, dark, humid, writhing in life. Now I know what an alive soil looks like. and I can imagine that this is the type of soil that a coffee plant would love to sink its roots into. Because this is the soil you would find in a natural forest. But then I remember that this isn't a natural forest. This is a commercial coffee farm, and the thing about coffee farms is that they are extractive, right? Every year the coffee plants take in all these nutrients and moisture and they put so much energy into creating these sweet, juicy coffee cherries.

Now, in a forest, these cherries would be eaten by other animals, they'd fall on the forest floor, and they would be recycled, nourishing the soil again, and all the living things in it. But on a coffee farm, we pick off these coffee cherries and take them away. All that sugar, energy, nutrients – it's removed from the ecosystem. And if we don't put nutrients back in, the soils eventually run out.

And eventually, the coffee plants won't have enough nutrients to produce coffee cherries anymore. Thinking back to my conversation with Lalo by the river at Let's Talk Coffee, he explained how that Guatemalan farmer producing coffee conventionally fixed that problem of soil depletion. He would add nutrients back into the soil by throwing blue pellets of fertilizer which contained the three major nutrients that plants need: nitrogen, phosphorus, and potassium. We're trying to supplement that with imported energy in the form of chemical fertilizer, but it's not enough. Plants need a whole swathe of micronutrients, plus a diverse biology in and around their root systems to thrive and resist diseases. Looking around me on Don Rufino's farm, in this home compost pit, I think to myself, “This pile of rotting banana skins and moldy mangoes surely doesn't have enough nutrients to replenish the hundreds and hundreds of coffee trees he has on this farm.” But Don Rufino walks me down to where we park the cars at the bottom of the driveway and we stand in front of that enormous pile of rotting muck. I mean, it is an enormous pile of rotting muck.

But it's also his very carefully controlled organic fertilizer. This mound of rotting mess, it's almost as big as a car and it sits under a metal corrugated roof on stilts. And on one of the beams, I spot a little picture of a blonde coloured dog. Yhat's Don Rufino's dearly departed dog, Boxer. And he named his farm after him.

Don Rufino explains to me what is in this compost. The bulk of it is coffee cherry. When you pick a coffee cherry off a tree, you just want the hard green bean inside it, not the soft gooey cherry flesh. So, he adds all of that into a big pile, and then he adds ash, chicken dung, and sand with a very high phosphorus content. Plus all the scraps from that compost heap next to his house.

Now, here's the thing: this is a commercial coffee farm and the coffee trees need access to those nutrients quickly so they can keep producing coffee cherries year on year. And as we know, when we throw an orange peel on the ground, it takes weeks and weeks to break down. This enormous pile of rotting coffee pulp and chicken dung and sand, if Don Rufino would have thrown that onto his plants as is, it'd take a long time to break down and for all those nutrients to sink down into the soil. Don Rufino has to speed up the process. And he does it with these two ingredients, which felt to me like the magic ingredients in a witch's potion.

The first of these two magic ingredients is mountain microorganisms.I had no idea what Don Rufino was talking about, so he took a few steps back, looked on the ground, and then picked up a stick. It was a piece of old wood, broken off from a tree, that had been lying around for a while, and in and amongst the dark brown bark were these interconnected patches of this flaky white material.

This is mold. Fungi. Mountain microorganisms.

I actually have a video of Don Rufino showing me this on my Instagram @FilterStories podcast. I'll put a link in the show notes.

Don Rufino says he walks into the nearby forest and picks up 20, 30 pounds of this white fungus (turns out, decomposing leaves are some of the best sources for this), and he mixes it into that giant heap of rotting coffee pulp.

Coffee plants love microorganisms, lots of fungi, a key piece to a healthy soil ecosystem. And here's the thing about fungus: plants love some types of fungus, and they don't like other types of fungus. It's all about having the right type of fungi in the soil to create an ecosystem where it works together as it should. It helps bring oxygen into the soil, it makes nutrients available for the plants, it helps the plants fix nitrogen down into the soil, and it also helps the plants resist diseases. So Don Rufino throws these wild mountain microorganisms into his coffee pulp pile, and he wants them to spread throughout the pile. But that's going to take a long time, hre's got to speed up the process.

Which leads me to the second magic ingredient. In front of us is a large plastic round tub. Don Rufino takes the lid off, grabs a cut-up plastic container, scoops it down, and pulls out this dripping, thick, rich goo. This is molasses, similar to a dark honey. It's used in cakes, cocktails sometimes. But for Don Rufino, this is sugar, energy, for the fungi, the mountain microorganisms.

Don Rufino explains, the mountain microorganisms eat up all the sugar, the fungus multiplies like crazy, the mountain microorganisms then spread throughout this compost heap, which is why I see these big white streaks running through the black moldy pile. This pile is now decomposing so quickly that when Allison Streaker and I get close to the pile and put our hands near it, it's scorching hot.

James Harper: So this decomposing pile of Organic matter writhing with life is what Don Rufino shovels onto the base of each of his coffee trees. This is how his coffee trees on this organic farm get nutrients, replenishing the soil with new nutrients. That is just one piece of the farming jigsaw puzzle.

But what about pests and diseases? So, thinking back to that conventional coffee farm in Guatemala that Lalo was telling me about, there, the trees needed to be sprayed with fungicides and insecticides because pests and diseases would come along all the time and the plants were getting crippled by them.

They couldn't fight them off. Now Don Rufino definitely does use some bug spray. He opens one of his sheds to show me what it looks like. And you know, it's not this industrially produced chemical that kills insects. It's more of a homemade organic bug repellent. But there's a huge difference between what Don Rufino is doing and what conventional farmers are doing.

Here are the ingredients of a chemical insecticide you might find on a conventional coffee farm: they typically contain organophosphates, which are derived from phosphoric acid, pyrethroids, a synthetic chemical and carbamates, from carbamic acid. And all of these chemicals are manufactured industrially. When I visited the Rouse co-operative, the organic co-operative that Don Rufino is a part of, I found the manual for how they make their homemade, organic bug repellent.

Are you ready for this? So here it is: mash a pound of garlic, onions, ginger, chili, and bay leaves all together in a bucket. Then pour a gallon of vinegar, molasses, sugar cane juice, and water, which has some amount of microorganisms floating around in it. You mix it all together, let it sit for 15 days, and voila, you can spray it on your plants. I mean, it sounds absolutely putrid and I guess putrid enough for even insects that love putrid stuff to be like, “all right, all right, all right, that's enough, that's enough, too much for me. I'm going to go over to this other plant over here instead.” But this is the point.

On Don Rufino's farm, he doesn't need to spray hardcore pesticides on his plants. He just needs this somewhat mild repellent because fundamentally his trees are stronger, healthier, more resilient compared to trees on a conventional coffee farm and they just don't need as much help to fight off pests and diseases.

Now, in an earlier draft of this story, I did try to explain why it is that coffee trees on conventional coffee farms with agrochemicals are much worse at resisting pests and diseases and frankly, it was just too technical for this kind of podcast. I will sum it up very simply though. On a conventional coffee farm using agrochemicals, yes, the trees can look really green and lush, nut that is deceptive, because without the biology, the fungi in and around the roots, they spend way too much energy, scarce, scarce energy, trying to build an ecosystem around their roots, they don't have enough energy left over to build an immune system. The key point though is although a plant can look healthy, it doesn't mean it is healthy.

Lalo Perez Varona - Buna: And unfortunately, aesthetic appearances or appearances are deceiving. And it's especially true with health and biology.

James Harper: Lalo gave me the example of us: A human, say you look at a human and that person looks completely healthy to you. They have all the parameters of health, but really they have a chronic disease inside of them.

When I learned about this, it was really game changing for me. I understood much better how to think about plants, and I want to share these learnings with you. Just not in audio because it's kind of too technical so what I'm gonna do instead is create an infographic on Instagram. I'll put a link in the show notes. So, back at Don Rufino's farm, he knows that healthy trees have a very vibrant ecosystem in and around their roots. This is the protection mechanism against pests and diseases. He can't use chemical sprays, so he has to rely on the plants being as healthy as possible. And to help nurture that complexity in and around the soil, he shows me how he plants a mind boggling number of shade trees. Going up the mountain slope from his house, he and I are stood in a field of coffee trees. I look around and I see so many different types of trees. And I ask him, what are they? And that was a mistake. Because he spends the next 5 minutes listing them all.

So, he's got mango, pepper, not one but two species of avocado, one of which is coloured purple, bananas, limes, pineapples, oranges, another kind of orange. You know, he has so many fruit trees, he says he never has to go to town to buy any fruit. And sometimes he doesn't even have to buy medicine; he grows medicinal plants, like the Hypericum, which when you cut it releases an acid which can cure infections and itches.

And he mentions so many types of trees I have never heard of. So Don Rufino and I, our gaze comes down from the shade trees above us to the coffee trees all around us. And it's here that he tells me how he prunes these trees very often to keep them healthy. He removes the weaker branches so the tree can focus its limited energy on growing the strong branches, and as we're standing next to a coffee tree he decides, you know what, this tree is going to get a total refresh right now. Don Rufino explains that this tree produced so many coffee cherries this year that the next harvest is going to be kind of low. By cutting it down, it'll regrow again, stronger.

The time has come to say goodbye to Don Rufino, and I do what I always do when I visit a coffee farm: I taste a coffee cherry, and it's delicious.

Driving down to the local town, Marcala, I think to myself, this is an amazing way to grow coffee. The trees seem healthier, stronger. The birds are happier. The environment is happier. Don Rufino, he's a happy guy. He loves this stuff. We avoid that enormous CO2 footprint from using nitrogen-based fertilizers. There are fewer landslides, less agricultural runoff into rivers because the soil structure is stronger.

Why isn't all coffee grown this way? That's because growing coffee organically is hard, much harder than doing it the conventional way. And in the next episode, I'm going to show you the story of RAOS, Don Rufino's Cooperative. They are a success story today, but the farmers who chose to go organic had to overcome so many hurdles, and I'm going to give you a taste of what those hurdles look like.