Researches regarding the conservation of soil fertility function of soil tillage systems

Human action upon soil by tillage determines important morphological, physical-chemical and biological changes, with different intensities and evaluative directions. Understanding of these changes, positive or negative, and their effects on the next evolution of tilled soils is the main purpose of this work. Basic characteristics as: structure, humus content, physical indexes in the case of haplic luvisol are changing function of type and intensity of tillage and crop. The changes are reversible in the meaning that soil tends to re become to the initial status if the destructive factors do not exceed the normal limits. The results of a three years crop rotation, in the fields of the Didactic Experimental of University Agricultural Sciences from Cluj-Napoca are presented.