At this year’s 4th Agroforestry Congress in Montpellier, Forests News caught up with Jianchu Xu. Jianchu, a scientist at World Agroforestry Center (ICRAF), ponders how agroforestry can help a bourgeoisie class eat exotic foods sustainably, the fashion of soil health, and just why oh why more people don’t study mushrooms? After-all, besides being “very beautiful,” fungus is a multibillion dollar industry…

So Jianchu, thank you very much for meeting me. 2019 feels like a monumental year, there feels like there’s change a foot, why agroforestry? 

Agroforestry is already dealing us a system. So in agroforestry we not only talk about diversity, but we also talk about flexibility and the dynamic. So this allows you, if you are innovative enough, to think about using a different approach to solve the different issues. That’s simply why agroforestry is so popular in 2019.

How do you see it as a solution? What kind of problems are there that need to be solved where agroforestry can step in and be the innovative solution to our issues we’re facing?

Agroforestry is a big umbrella, it’s not just species based or technically oriented, no, it’s a social institution. It’s a bigger framework that goes from producer to consumer. Because now today’s consumer is unique: they’re not only satisfied with the rice or bread, they need diversity in each products, or want exotic products. Today go to China and say, ‘avocado,’ they say ‘oh avocado!’ It’s so fancy to have avocado, it’s the fashion. So today’s urban needs are different from the past. So that’s why agroforestry is not only about technology, it’s about social institutions, social movements, it’s about the fashion.

Does agroforestry then provide an answer to the needs of a more bourgeoisie class that want to eat out of season and, some might even say eat unsustainably? Is agroforestry a potentially more sustainable way to do that?

Yes, because in agroforestry we often think about agroforestry in rural areas but now today’s agroforestry is everywhere: it’s in the urban system. So agroforestry is a multiple way of syncing, I often use agroforestry as symbolically linking 3D, vertical and dynamic. So agroforestry can help you think about the tree from a different angle, also from even below ground. Today there is another fashion: we talk about soil, looking at the interaction between below and above ground.

You’ve said that soil is something that people are becoming more aware of. What role does agroforestry have to play in soil health?

Agroforestry is a very powerful tool to engage different stakeholders. It’s simply to bring back to nature. The tree is very symbolic, even the public talk about carbon sequestration solutions in tree planting as a popular concept. That’s one. The second is that scientifically, we talk about the soil committee, and now I’m talking about two types of soil. One is a virtue soil: to think about how to plant a tree without soil. So that means you turn any waste into substrate with compost. So today urban people also supply with soil [by doing this]. Of course, how a tree links with soil, that’s another dimension. How to basically enhance the soil carbon, to enhance the quality of foods, but also sometimes we have more carbon in the soil, so we can sequestrate the greenhouse gas emissions.

So agroforestry is a way to not only give us food but also to sequestrate carbon, providing another solution to help combat climate change?

Yes agroforestry is a very simple way, it’s the most economic way to sequestrate carbon at the landscape level. It’s definitely the smartest solution for climate change.

So Jianchu, how do you even do a circular agricultural system?

We often ask the farmer to plant trees and cover the grass, but the farmer says, ‘Can I get the income?’

And as an ICRAF scientist, we say “yes” and they always say “how?” And I say that we have a mushroom factory and can buy biomass from you. What kind of biomass you have, we are taking it. So, we make a different substrate for different mushrooms species. Some are multiple in woody biomass, some more vegetative biomass like elephant grass, so we have a different mushroom species which needs a different substrate. That’s one story.

See, mushrooms are grown by one group of farmers. We then replace it with a new mushroom and give it to them. We collect back from them the older mushroom and make a new composite, so we make a compost fertilizer, to give to another farmer to grow mushrooms, and then do it again. So the story is you can always make circular work.

You see a chicken farm supported by government on a large scale which houses a hundred thousand chickens- well every day they have waste, the main ingredient is faeces. This waste- our government is not allowed to dump into the field, or into water because of pollution. Well I say we put insects inside the waste and in 20 days the insects grow from very young baby to big insect. The insects we put into bio reactive…we put them into organic fertilizer, and into liquid fertilizer for drip irrigation. Or you develop – because you see insects are mainly protein – to use the insects as a feed for fish. The story is always going: with the fish waste you use more insects to process. With the fish, we are working on a large-scale tilapia farm. We are meeting the European standard of high-quality tilapia meat, which can be exported to Europe. And then this waste again cannot go outside the ecosystem. So then we need insects, again! See the story is circular.

What role do the insects play?

The insects convert wood biomass and fibre biomass into protein. It’s a conversion: the insects themselves convert 100 percent biomass into 100 percent equivalent protein. That’s very efficient compared to chicken, pork and cattle.

What happens to the insects?

Insects are a matter purpose: you can sell them to urban areas for feed for pets, and then you give feed to the duck, you give feed to chickens, it can replace all fish powder in any sort of livestock or animal feed, like for cattle feed or duck feed. Or we put it into ammonium acid fertilizer, because now intensive farming needing drip irrigation, combines the fertilizer with water – so that’s the main function of insects. We tried to use live insects to feed another [unidentified] fish. [Unidentified] fish have a very high value, because they have less bones. The Chinese, we like the fish alive you know, the fish, with the insects, when they sell in the markets, they are still alive.

There aren’t many people in the field linking agroforestry, agroecology with circular agriculture, how easy is that?

It’s not easy, but most of the challenge is that you need a system of syncing, so the problem now today is, ‘Oh I’m trained as an insect expert, you’re trained as a tree expert,’  no-one is talking to each other. So today we need to be trans-disciplinary. The insect experts need to know how to manage a tree and plants, and vice versa. So being trans-disciplinary and the systems of syncing is the first one. The second is that you cannot invest without a return, so you have to listen to the market. Where is the market? Particularly for the new models, the new products, the new markets? So that is where you need scientific innovation, you need to calculate how much labor, and what is the cost of infrastructure. Then you need to engage the stakeholders to convince everyone, and make everyone happy in the process.

Why are mushrooms so under-researched?

Okay, because I’m a scientist and I can’t easily train students to publish five or ten papers for one PhD because, again, very few people study mushrooms and fungi. In the past five years, my team have published more than 1000 new species: so make your citation, make your impact factor high, then go to mushrooms. Example, we had a fungal diversity article in a journal, it had an impact factor of 14 [the impact factor is used to measure the number of citations in journals for a single piece of research, the average factor score hovers around the 1.0 mark]. So, that’s one. The second is also that mushrooms are very beautiful. You find a different color, a different shape, yet nobody pays attention. Everybody pays attention to flowers and fruits, but nobody pays attention to mushrooms. Recently we found a mushroom that’s very shiny and blue color, and the  public pay attention and sayid, ‘Wow, what a strange thing in nature to have such a kind of color!’ It really attracted attention. Finally, mushrooms have value. In my province we are talking about a billions, billions dollars industry in mushrooms. We export to Europe and now the Chinese market is also coming. Another high value is truffle, and they have medicinal value in the lingzhi, the ganoderma, which are linked to having anti-cancer components.

Is that a problem that mushrooms aren’t charismatic or beautiful to look at, so they kind of fall out of favor with even the science community?

Today we are struggling. In certain science we have advanced, but in certain fields we’re still not so advanced: that’s the entire fungi kingdom.

You look like a fun guy!