Abstract: A method for the production of fiber pulp from lignocellulosic material containing at least 70% spruce or spruce-like material. The method comprises the steps of lignin softening and defibration/refining, the step of lignin softening being performed prior to the step of defibration/refining and comprising impregnating the starting material with a dilute aqueous solution of a lignin softening agent, namely a solution of sulfurous acid, metal bisulfite salts and/or metal sulfite salts in an amount sufficient to provide a defibrated/refined pulp containing an absorbed and bonded amount of sulfonate groups within the range of from 0.06 to 0.75 wt.-%, calculated as Na.sub.2 SO.sub.3 and based on the dry pulp weight. The absorbed and bonded amount of sulfonate groups is balanced to the composition of the starting material and the temperature-pressure conditions in the defibration step to provide a pulp of maximum tensile strength such as to represent a point within the polygon ABGH in FIG. 1.