Concrete development, erosion, or salinization: our soils are visibly deteriorating all over the planet. Hence the question: are we destroying the earth that feeds us?

To answer this, we welcome Marc-André Selosse, a biologist specializing in soil life, professor at the National Museum of Natural History, and author—among other works—of *The Origin of the World*, a natural history of soil intended for those who trample it.

Interview by Maxime Thuillez

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00:36 - Introduction, presentation of Marc-André Selosse.

01:57 - What is soil? Can you give us a definition?

04:13 - At what depth is soil?

05:13 - Is soil also the link between rock and life?

06:48 - What are the main ecosystem functions of soil?
09:50 - Do dams that retain sediment have a direct effect on marine biodiversity?

11:53 - One of the major issues is soil sealing, that is, the destruction of soil to build roads, parking lots, stadiums, roundabouts... I'm going to ask the question naively: what are the problems posed by soil sealing? And what is the extent of the phenomenon? Is it a silent massacre of our soils?

14:49 - What impact does soil sealing have on flooding?

16:01 - We clearly sense a relationship between plants, forests, water, and soil... what are these interactions? What role do plants play in the soil?

18:54 - In the book "Origin of the World," you say that when a forest is cut down, the water table can rise. What are the interactions between forests and soils?

21:22 - Those who work the land and the soil are farmers. We're going to talk about an age-old practice: plowing. What are the agronomic benefits of plowing... and why is this practice being questioned today?

25:01 - Could you remind us what erosion is?

27:14 - You mentioned the Beauce region... What is the state of the soils in France...? What is the state of the soils worldwide?

28:44 - Which regions of the world are experiencing the most significant soil erosion?

32:22 - You mentioned the Dust Bowl, which displaced hundreds of thousands of people in the United States... Are we likely to see migrations linked to soil degradation in the coming years?

34:06 - There's another practice that can degrade soils: irrigation. Can you explain why irrigation can degrade soils?

37:13 - Which regions does this affect? ​​We're thinking of Asian countries that irrigate extensively, such as Central Asia or Pakistan. Which regions are most affected?

38:30 - What is the role of livestock farming on soils? We see regions becoming desert... I'm thinking of the Sahel. What is the impact of livestock farming on soils?

43:04 - We've talked about soil sealing, tilling, irrigation... we talk relatively little about soil pollution, and especially plastic pollution. How concerning is this phenomenon?

46:45 - What is the role of pesticides and fertilizers on soil life?

51:18 - Soil is an inheritance for future generations... is soil something we pass on to our children? We can't afford to destroy it, can we?

54:16 - Soils are generally quite misunderstood. One particularly poorly understood aspect is the interaction between soil and climate. How does soil impact the climate?

58:23 - How can we explain that the "4 per 1000" target, launched, if I remember correctly, during COP21, doesn't seem to be generating much enthusiasm?
01:02:04 - The 19th century was teeming with naturalists... today, it seems our elites are scientifically illiterate and have a complete lack of understanding of the life sciences and how living things function?
01:04:44 - What message do you want to send to our listeners? How can we resist the destruction of the soil?