There is no alternative to soil liming as an environmental protection measures. It is difficult to overestimate the role that the application of calcium ameliorants has on soil properties. But besides a positive effect on soil properties, liming leads to some deterioration in the conditions of potassium plants nutrition. For studying this circumstance, researches were carried out in a long-term stationary experiment on leached chernozem in sugar beet agrocoenosis in the Voronezh region. It is established that the application of mineral fertilizers in doses of NPK of 120 and 240 kg / ha has resulted in a decrease of exchangeable calcium content in comparison with the backing variant by 0.7–1.2 mg-eq. / 100 g of soil. At the same time, there was an increase in soil availability of exchangeable potassium by one class in contrast with no treatment. In the case of soil liming, this process was less revealed — soil availability with exchangeable potassium remained at the level of control. With the application of mineral fertilizers on the back of organic aftereffect, the content of fixed potassium increased. The use of N120P120K120 provided 26 mg / kg of soil for a higher content of fixed potassium than the application of N240P240K240. The highest content of fixed potassium was observed with a joint consequence of manure and defecation - 649 mg / kg of soil. An increase in the activity of calcium ions in the soil led to a decrease in the activity of potassium ions. The interinfluence of these indicators was intensified by applying calcium ameliorants into the soil. The correlation coefficient between the pCa value and the potassium potential of the non-liming soil was - (–0.675) before sowing sugar beet and (–0.684) before harvesting, and on the ameliorated variants (–0.814) and (–0.500), respectively. Applying mineral fertilizers on various grounds increased crop yield by 16.0–18.2 t / ha in comparison with no treatment.