The aim of the studies and research on which the present paper is based was to assess the way in which certain agrochemical indices of the soil are modified under the influence of mineral fertilization. Soil, as the main means of production in agriculture, must be considered as a strategic natural resource, which is sustainable if exploited in a scientific way. It can bring its contribution to ensuring food supplies, and food safety. Exploiting agricultural areas by using incomplete or incorrect strategies has serious consequences, both from a quantitative and a qualitative point of view, on soil resources and also on agricultural yields, and the lack of fertilizers or improper use of fertilizers are elements of such a strategy. In our country, agriculture has undergone major changes after 1989. Here we make reference to a change in the form of ownership, a legislative system that is not a stimulus for farmers, the fact that many landowners are not properly prepared and trained in the matter of efficient use of land, poor endowment with equipment, lack of own financing, the incapacity to access investment funds, etc. The structure of crop plants has undergone quite large changes in Banat Plain, Timiş County, as it has in other parts of Romania. The area cultivated with leguminous plants (be they annual or perennial), has much diminished. The predominant crop plants are wheat, maize and sunflower, and at a much smaller scale are barley, two-row barley, soybeans, oil rape, sugar beet (which has been less and less cultivated in recent years), with small impact in the realization of sustainable crop rotation. Under these conditions, people mostly use simple rotations wheat-maize or even monoculture, and fertilization is based almost exclusively on mineral fertilizers (in many cases unilateral with nitrogen), with high fluctuation from the point of view of the quantity of active substance from a plot of land to another. That is why the agrochemical characteristics of the soil undergo large modifications, with a negative impact on fertility. The paper presents the results of the research on the changes of the agrochemical indices represented by pH, N, P, K in the context of an agricultural system based on field crops and a mineral fertilization system with variants which cover different situations met with in the agriculture of the reference area, namely Banat Plain.

soil fertility; agrochemical indices; mineral fertilizers; fertilization system; vegetal agricultural systems; correlation

Presentation: oral