A variable rate fertilization plan allows you to accurately determine how much fertilizer is needed in specific areas of the field, taking into account the results of soil tests. This helps to avoid over-fertilization or under-fertilization. When fertilizing with variable rates, the optimal amount of mineral fertilizers helps plants receive the necessary amount of nutrients, and therefore the quality and quantity of the harvest. On the farm of the K?dainiai Plant Nutrition Club (CNC), after testing the soil and starting to use plant fertilization with a variable PK rate, potash fertilizers were saved. Previously, farmers would purchase potash fertilizers by calculating the potassium (K2O) requirement based on the planned crop yield. Soil testing revealed that there were significant amounts of mobile potassium in the soil. Variable rate fertilization allowed for the uniform distribution of bulk fertilizers, both in terms of the respective amounts of PK in the soil in different fields and in individual areas of the fields, resulting in more uniform plant development and lower cultivation costs, saving on potash fertilizers.