This document specifies the procedure for the determination and calculation of the dry matter fraction of plant biostimulants for which the results of performed analysis are to be calculated to the dry matter basis. This document is applicable to the fertilizing product blends belonging to PFC 7 where the EU fertilising product plant biostimulant contained in the blend represents the highest % by mass in the blend. In case of equal shares, the user can apply either this or the standard(s) applicable to the other component product(s).