Imagine a public protest, a procession or a social media campaign that uses the slogan “We are …”. And if the missing word was ‘soil’? We have seen many slogans over the years, but never “We are soil”. Extravagant? Illogical? Not at all, according to the soil defence engineer Paolo Pileri, full professor of Urban Design and Planning at the Politecnico di Milano, where he lectures on soil use, sustainability and green urban design. For Pileri, understanding the soil-humanity equation is essential for defining actions to preserve the existence (and happiness) of the human race.
In the preface of your latest book “Dalla parte del suolo. L’ecosistema invisibile”, (Laterza, 2024) you state that ‘the authentic reasons of the soil continue to not be understood for what they are’. Can you explain these reasons for us?
Soil has its own life, its own population, it is inhabited by a multitude of life forms that dialogue and cooperate in a way that we are not capable of doing. It is a place of very delicate and very fragile balances. These balances allow soil to offer the planet an infinite number of benefits: it is the great artifice of climate control; not just plants, as people continue to assert today: plants of course, but together with the soil and mycorrhizal fungi.
The pillars of soil life lie in their ability for symbiotic cooperation, and today this is still not understood. As I always tell my students, soil life is continuously threatened, not only by our projects by especially by the fact that we do not think of the soil. And we certainly don’t think of it as a living, ecological body.
The great effort required, together with artists and all the cultural organisations that are able to give a voice to soil, is to help people understand the treasure we have beneath our feet and which demands our respect.
Humus, for example, is still partly unknown: it is an element that we must focus our research on, a priority objective over all others, and certainly one that needs our attention well before we send tourists into space.
How would you define humus?
Humus is a wonderful form of energy. It is a unique and pondered mass organisation, it is energy that lies on the upper surface of the planet, something immense, very generous and very vulnerable, and ready to sacrifice itself. In contrast to humans, when the earth has something precious to offer it gives it: this is humus.
In the preface to your book, you state that “consuming soil means ‘violating the integrity of the self and the environment”, as soil and community are inseparable. What are the consequences of this separation?
Only a part of humanity believes it is suffering because the ecosystem is under stress. All the others are convinced that they can dominate the earth, reaping resources that they believe to be infinite, thinking that technology can help them to perpetuate their aggressive model.
In the last one hundred years, we have focused on living on tarmac, a means for separating us from nature. Our ‘natural’ environment is made of tarmac. Where there is none, people wonder why they get their feet dirty, as if soil was the problem: this is exactly the opposite of what it should be. It is understandable that we need tarmac, but it is unacceptable that there is so much tarmac, it is so dominating that we think that anything that is not tarmac is dirty.
We lie within this framework, and it’s complicated to understand where this disassociation we are stuck with will lead us. Our green efforts today have merely generated a few hiatuses to protect nature: parks are just 10% of the environment we live in, but we know that we have psychoses, asthmatic diseases, behavioural problems and anxiety due to the lack of natural spaces; despite this, the issue is not at the top of the public agenda. There is so much to do also in narrative terms: we need to listen to the earth and ecosystems everywhere, not only in the scientific circuits. Indeed, the time has come to go beyond these circuits and understand how communication must engage everyone, with an accessible and understandable language.
How it is possible to reconcile the complex system that much of humanity lives in today with the safeguard of soil? Don’t you think we need to compromise?
We often think that certain compromises are inevitable, but I believe they are exactly the ones to be avoided. With all these compromises, we are not laying strong foundations for the future. We must be able to reason in favour of nature, the challenge is to come up with efficient but uncompromising economies. To be real, ecological transition must give us a few headaches. We’re not talking about going back to the stone age, but reducing waste and getting rid of the many superfluous (and often harmful) comforts we are used to. Two simple examples? Using the car even when you don’t need to, or eating too much meat.
To avoid consuming more soil, for example it would be enough to start working on the existing building heritage. Today in our country there are no updated and accessible records of the unused buildings. Without these data it is hard to produce sustainable development plans, even for decision-makers or researchers. In in report produced a few years ago, we noted that reusing abandoned buildings today would prevent soil consumption for the next five to eight years.
How can we develop a correct relationship with soil?
First of all, by preserving its ecosystemic function: without soil there is no water, no plants, many vital life cycles involving carbon, nitrogen, phosphorus or potassium would be harmed. Soil has the ability to store carbon in the first metre, making it a great climate regulator, in fact four times more carbon is found in the first metre of soil than in all the vegetation on the planet. And 30% of biodiversity is found in the first 30 cm of the soil. Knowing these data, which seem taken for granted but are not, should help us reflect and, above all, act on behalf of the soil.
