Approbation of a new method of soil fertility testing is given in the article. To identify the biological activity of soils, it is proposed to take into account the morphometric reactions of the phytotest and to compare them with the normal mathematical distribution characteristic of the rate of reaction of a plant population homogeneous in genotype against stable cultivation conditions. Seeds of Triticum durum are used as a test object. The soils processed by biological preparations: Flora-with, Fitop-Floras in a combination with natural zeolites were tested. A hypothesis is put forward: factors that cause the normalization of the distribution of morphometric characteristics of seedlings in the phytotest contribute to the conservation of the gene pool and the full realization of the reproductive potential of the population. The new testing method is based on the use of the authorial computer matrix based on MS Excel and statistical criteria. The validity of the method was determined by the correlation of ranks obtained by summarizing the signs of optimization of cultivation conditions in laboratory and field experiments. The article points out high validity of the method, and the statistical indicators that allow an objective assessment of the mathematical characteristics of the plant population.