The article presents the determination results of the economic balance of potassium in the leached chernozem, when applying different types of manure and urban sludge as fertilizer during the years 2010-2020. The results showed that the potassium balance for non-fertilized variant (control) is negative and constitutes -110 kg/ha, at the application of manure and -62 kg/ha for urban sludge application. The application of different types of manure and municipal sludge in a dose equivalent to N170 kg/ha maintained a positive potassium balance from +53 kg/ha to +227 kg/ha. When the fertilizer dose was doubled, the positive value of the potassium balance also increased, which was corresponding: for cattle manure +622, mixed manure +459, poultry manure +97, pig manure +135 and urban sludge +164 kg/ha.