EN
On a base of field experiment there was studied the effect of long-term straw, manure and mineral fertilization application on changes in hydrolytical acidity in a soil under winter wheat or spring barley monocultures. It was found that fertilization significantly differentiated the hydrolytical acidity value in the soil under both monocultures. The highest acidity in relation to an object with NPK + Ca was found where native straw and straw with nitrogen additive were used. The value was close to that for mineral fertilization without calcination. The manure acted to decrease the hydrolytical acidity, which was in opposition to the native straw as well as with nitrogen additive.There were found no significant differences between mean values over particular years, but the tendency to increase it in last year when elevated precipitation took place. Studied acidity value at three layers of the soil points to its lowering along with the depth of a soil profile.