Abstract: A solid mineral composition including the following formula (I): Calcium carbonate from 4.58% to 77.8%, Dolomite from 3.85% to 69.29%, Rock salt from 5.7% to 12.4%, Lignosulphate from 4.25% to 8.49%, Potassium sulphate from 0.37% to 2.44%, Magnesium oxide from 0.01% to 0.07%, and Elemental sulphur from 0.009% to 0.066%, the above percentages consisting of the weight percentages of each of the compounds, relative to the total weight of the mineral composition dry matter, for increasing the fertility of a soil by causing an increase in at least one enzymatic activity contained in the soil, selected from (i) phosphatase, (ii) ?-xylosidase, (iii) ?-glucosidase and (iv) ?-glucosidase.