A new quantitative (digital) method for assessing the growth and productivity of agricultural plants has been developed. Taking into account the results of laboratory, vegetation and field experiments, E.A. Mitcherlich, A.T. Kirsanova, D.A. Sabinina and other soil scientists, the article proposes a digital model of plant growth depression, when, for example, when a large amount of soluble fertilizers (or any other growth factor) is applied, a decrease in yield follows; with an increase in air temperature, the yield of plants increases, but at a very high air temperature, plants dry out, etc. For conditions of plant growth depression, Academician E.A. Mitcherlich proposed to use the equation: , k – damage coefficient (depression coefficient): it was found that this solution is erroneous. In the article, a new solution to the problem of growth depression is obtained, taking into account the peculiarities of plant growth and development. In the new digital model of plant growth and productivity, it is assumed that the yield (y) and its increase increase with an increase in the number of growth factors (x), in proportion to the amount of yield (A-y) that has not reached the maximum potential yield (A), and the possible value yield (B+y), above some minimum (initial) value (B) of the crop. In the article, simple general formulas are obtained that determine the supply of nutrients in the soil, the yield value, the depression coefficient, etc.; examples of calculations are considered.