The paper presents the results of the researches carried out at the Agricultural Research Station Oradea, between 1996 and 2002, regarding agricultural yield of spring wheat, cultivated on a luvosoil polluted under control with oil brought from the exploitation site at Suplacu de Barcău, Bihor County. The experimental device was made out of micro parcels of 1 m², set up in a randomized manner, in a Latin square, polluted with a concentration of: 0, 1, 3, 5 and 10 % (0, 3, 9, 15, and 30 l/m²), oil in the ploughed layer, in 4 repetitions. The experience was than cultivated with in the first three years with millet, a plant that is considered to be resistant to pollution, and than until 2002 with spring wheat. The analysis of the yield losses from the parcels polluted with oil in various concentrations, have shown that these decreases in time, becoming insignificant after 7 years in the concentration of 1 %, 8 years in the concentrations of 3  - 5 %, and 9 years for 10 %. This shows the biodegradation of the oil without any sort of agropedomeliorative measures. By analyzing the correlations between the wheat yields in the last 7 years of research and the climate factors (rainfall and air temperature) registered in the vegetation period, very significant square, spatial polynomial correlations were established for each oil concentration. The fact that correlation report decreases from 0.7458, for the parcels unpolluted (0 % oil), to 0,4170 for the parcels polluted 10 % oil points out the influence of the increase of the pollutive agent.

oil pollution; luvosoil; biodegradation

Presentation: oral