Abstract Crop production capacity is greatly influenced by soil quality. Soil quality is determined by physical and chemical characteristics, some of which may or may not be economically controlled. Chemical characteristics that influenced soil quality are: soil reaction, exchange capacity, organic matter and essential plant nutrients content. In general if physical characteristics are satisfactory, chemical properties can be modify by adequate use of mineral fertilizers, manure, green manure plow downs and other organic additives. Improper fertilization contributes to soil infertility. Over-fertilization increases salinity in the soil and inhibits plant uptake for some nutrients. Under-fertilization fails to replace macro- and micro-nutrients previously removed by plants and environmental actions. A special importance should be given to the type of fertilizer to be applied . The aim of this paper is to monitories the changes of soil chemical properties like soil reaction, cationic exchange capacity, humus and N,P,K content after mineral fertilization. Researches in this area showed a significant correlations between the type and quantity of applied fertilizer and modification of main soil chemical features. Our research was made on cambic chernozem, with six fertilizer treatments (different N, P, K doses). In plots with nitrogen fertilization only nitrogen was applied as calcium ammonium nitrate, in plots with NPK fertilization complex fertilizer was used.  After soil sample analysis the effect of treatments on soil pH, CEC and N,P,K content were tested using ANOVA method, and the significance of their correlations was made by Pearson correlation matrix. Results  does not shows a  decrease of  pH value as shown by researches when nitrogen is applied as ammonium nitrate. The increase of the CEC value is not strongly influenced by soil pH and total nitrogen, being significantly influenced by phosphorus and potassium content of soil. To maintain a certain level of soil fertility is important to monitor the continuous changes that suffer its chemical properties after application of mineral fertilizers.

: soil quality, fertility, soil chemical properties, fertilizers

Presentation: oral