In 5-year investigations, carried out in 2000-2005 at the Production and Experimental Establishment in Bałcyny, on a lessive-type, gravity-gley soil of class IlIa, complex 4, the effects of different methods of fertilization in a 3-field crop rotation: sugar beet – spring wheat – winter barley were compared. The following were the methods subject to comparison: A – mineral fertilization only; B – fertilization with manure and mineral fertilizers; C – fertilization with straw, green manure and mineral fertilizers; D – fertilization with compost (ecological fertilization). In objects A, B and C doses of N were differentiated while fertilization with phosphorus and potassium remained constant. In the ecologically fertilized object (D), the dosage of biopreparations P500 (of cow-dung) and P501 (of silica) was differentiated. The aim of this paper is to estimate the effect of various fertilization methods in the crop rotation on changes in the chemical properties of the soil. After the 5-year period of investigation, the reaction of the soil in all fertilization objects did not change signifi-cantly. A mean minimal increase in the soil pH was recorded in objects fertilized with conventional methods. The highest increase in humus (by 0.38%) was recorded in the object fertilized with straw, green manure and mineral fertilizers, and in the ecological object (by 0.32%). In the last object the content of humus in the final year of investigation was the highest (2.02%). In total, the introduction of nitrogen in the conventional objects increased the content of humus in the soil of all objects. A higher content of nitrogen in the soil was observed in the objects fertilized with organic fertilizers, the highest being that in the object fertilized with the use of the ecological method. Nitrogen fertili-zation caused an increase in the content of nitrogen in the soil. The potassium content in the soil of all analysed objects increased significantly over the period of 5 years, which was also true for the object fertilized with the ecological method. Similarly, the content of magnesium and calcium in-creased in all of the objects after 5 years, and the soil fertilized with the ecological method was characterized by significantly the highest abundance of those elements.