THE RESEARCH FOR THE DEVELOPMENT OF AGRICULTURAL RECOVERY TECHNOLOGY OF STERILE LANDFILLS RESULTING FROM THE CURRENT EXPLOITATION OF LIGNITE

Abstract

The research was organized on the Balta Unchiașului tailings dump, Rovinari, Gorj county, a dump covered with 30 cm of fertile soil, aiming to establish the effect of fertilization with fertilizers, cattle manure, compost, lignite –based fertilizer and liquid fertilizer based on humates extracted from lignite on sunflower production and followed the effect of fertilization with mineral fertilizers, manure, compost and liquid fertilizers based on humates extracted from lignite, on the sunflower crop). The chemical characteristics of the crop substrate had a large variability and consisted of: pH values between 8.08 and 8.35, so a slightly alkaline reaction, humus values between 2.50 -3.52%, being valued as a low-medium level of supply, the level of nitrogen total between 0.101 and 1.60%, therefore a low-medium level of supply, mobile phosphorus between 25 and 44 mg/kg, therefore a medium-high level of supply. The most high values is recorded in the variants fertilized with manure and compost, mobile potassium between 152 and 315 mg/kg, so a medium - high supply level, copper between 18 and 23 mg/kg, so normal supply values, nickel between 30 and 37 mg/kg, so an average load, lead between 7 and 12 mg/kg, values that highlight a normal level of load, manganese between 473 and 595 mg/kg, so normal values, zinc between 48 and 66 mg/ kg, showing normal values and cadmium 0.17 AND 0.32 mg/kg so normal values. The sunflower plants can be used as copper hyperaccumulators.