5. Conclusion

Soils are highly complex systems, from both physico-chemical and biological points of view. In particular, soils are very rich in micro-organisms, and the diversity of their microbiota is remarkable. The combination of these physico-chemical and biotic characteristics makes each soil unique. These highly dynamic systems are the seat of highly complex interactions between the organisms they host, and between organisms and their abiotic environment. Moreover, agricultural soils and some forest soils are open systems that receive flows of inputs (fertilizers, pesticides, seeds and seedlings, irrigation water) to optimize production. Agricultural soils are therefore under considerable anthropogenic pressure.

Certain micro-organisms hazardous to human and animal health can be detected in soils. In order to limit the risk of contamination of raw materials destined for...