Anna Alexandrovna Lepikhina

Based on the results of a green pot experiment with mineral fertilizers on chernozem, a new method of plant diagnostics has been proposed, using the analysis of individual barley plants (Hordeum vulgare L.) according to their morphological characteristics of vegetative and generative development. Each plant was divided into three parts: the primary shoot, secondary shoots (together forming mature grain), and non-productive shoots. The dominant group of plants (Group D) was identified by total biomass, while the other two groups (Groups A and B) were distinguished by their level of generative development, determined by the quality of grain formed by different shoots. Structural differences among plants, shoots, and groups reflect the dynamics of barley development during the growing season. Different application methods for potassium fertilizer, namely localized and uniform, create different spatial heterogeneities of their content in the soil and, consequently, different dynamics of potassium's effect on the plants. Potassium fertilizers applied uniformly have the most significant effect during the first half of the vegetative period, when the primary shoot is most actively developing. The localization of potassium fertilizers in the soil, conversely, by promoting weaker fixation of potassium by the soil, prolongs its effect into the second half of the barley's vegetative period, when secondary-order shoots develop more actively. Therefore, the new method of structural division of individual plants made it possible to diagnose the physiological effect of the spatial heterogeneity of potassium fertilizer application on barley plants and crop quality. The traditional biomass accounting scheme, which averages all plants in a pot, was not sensitive enough to detect the effect of fertilizers on the formation of generative organs. Thus, the obtained data confirm the previously proposed concept linking the spatial heterogeneity of freshly applied potassium in the soil with its distribution within the plant throughout the vegetative period.