Ways out of the global soil crisis: opportunities and risks

About 30% of our soils are degraded, mostly due to unsustainable land use. These soils took centuries or millennia to form. Are they lost for generations, or can they be regenerated quickly? And how can these options cope with climate change?

The first part of the talk explains how long-term agricultural use degrades soils and how their properties can recover through management changes. It will discuss options for quickly regenerating such soils for agriculture and the challenges involved. History offers valuable insights: indigenous peoples in the tropics and early agricultural societies improved soils using biochar and organic residues with remarkable results. However, today these methods carry risks, such as yield reductions in temperate zones or the spread of antibiotic resistance from intensive organic fertilisation. The second part of the talk explores, therefore, the balance between opportunities and risks in sustainable soil use, concluding with recent findings on how subsoils might help resolve this conflict.