agroecological state of lands, the quality of agricultural products. Fertilizers and ameliorants as some of the most effective means of restoring soil fertility make a considerable influence on the agroecological condition and agrochemical indicators of arable soils in the process of their agricultural usage. The article researches such ecological aspects of using mineral fertilizers as changing chlorine content in soil solution, potassium, calcium and magnesium content in soil intake complex as well as gross natrium content in soil after continuous usage of fertilizers in field crop rotation. The experimental part of the work has been done in continuous stationary experiment in the field rotation of grain and beet crops with a set of crops traditional for the region defined in 1964. It has been defined that the chlorine of fertilizers does not produce stable compounds in soil and migrates a lot in its profile. Using fertilizers in field crop rotation in a dose of 45–135 kg of K2O/ha does not contribute to chlorine increasing in physiologically active 1,5 m deep soil layer.At continuous fertilizer usage there have been essential changes in the ashed fertile soil in the composition of its intake complex – the number of calcium and magnesium exchangeables has decreased which entails worsening physical and chemical qualities and as a result leads to decreasing fertility level. The research results have evinced that the ratio between magnesium and potassium in a soil intake complex drops to 2,6–3,6 as a result of continuous potassium with fertilizer usage, according to the checking data without fertilizer application it makes up – 4,2, which corresponds to optimal ratio Mg : K = 2–5.