Abstract: A method and a device for treating soil, by injecting a treatment product, wherein a soil auger (51) with a helical drilling blade (512) in which an outlet opening (515) is provided is driven into the soil (7), while a treatment product is injected into the soil (7), the injection pressure (P) and the injection flow rate (Q) are measured, and the injection pressure (P) is adapted as a function of a soil parameter (Ks,rel) derived from the measurement values of the injection pressure (P) and the injection flow rate (Q). The device comprises a drilling rig (5), an injecting device (2a), (2b), (2c), a measurement device (3) and a computer (4).