Use of a solid mineral composition for increasing the fertility of a crop soil or that of a prairie soil

A method of increasing the fertility of a soil by inducing an increase in at least one enzymatic activity contained in said soil, comprising:

• adding to the soil an effective amount of a solid mineral composition comprising:
• from 4.58% to 77.8% of calcium carbonate,
• from 3.85% to 69.29% of dolomite,
• from 5.7% to 12.4% of sodium chloride,
• from 4.25% to 8.49% of lignosulphate,
• from 0.37% to 2.44% of potassium sulphate,
• from 0.01% to 0.07% of magnesium oxide, and
• from 0.009% to 0.066% of elemental sulphur,
• wherein the above percentages are weight percentages of each of the compounds, relative to the total weight of dry matter of said mineral composition, and
• the solid mineral composition induces an increase in at least one enzymatic activity contained in said soil, selected from group consisting of (i) phosphatase, (ii) β-xylosidase, (iii) α-glucosidase and (iv) β-glucosidase.