The content of mercury in alfaalfa samples from gleyic chernozem

Abstract

Increased concentrations of heavy metals in some agricultural areas, primarily as a result of human influence, threaten, among other things, the production of high-quality feed. Medicago sativa Lis (alfalfa) is a perennial legume, which is regarded as the leading and most important forage crop for the production of quality feed and used in fresh and canned condition as hay, haylage, silage, meal, pellets and paste. The aim of this study was to determine the levels of mercury in soil and plants Medicago sativa L.. to obtain information on safety of this nutrient. The examination was conducted in Hrtkovei, in the Republic of Serbia. Examined soil belongs to the automorphic soils, humus-accumulative class, type of chernozem, subtypes on loess and loess-like sediments and variety gleyic chernozem, with profile Ajno-AC-C. Soil has a good physical and chemical properties and is suitable for the production of alfalfa, if contamination with heavy metals would not be a limiting factor. The study involved eight localities. Sampling of soil and plant material was carried out in May 2011., in the second production year of alfalfa. Soil samples were taken in a disrupted state with agrochemical probe, at a depth of 0-30 cm. Mercury content was determined by cold vapor technique, using atomic absorption spectrophotometer. The mercury content in soil samples of examined localities was below the 0.001 mg/kg, which was not exceeded maximum level of 2.0 mg/kg, according to the Regulations on permitted amounts of hazardous and harmful substances in soil and water for irrigation and methods of their analysis (Slu%beni glasnik RS, no. 23/1994). The content of mercury in Medicago sativa L. was below 0.001 mg/kg, which is below the maximum permitted concentration, according to the Regulations on the quality of the feed (Sluzbeni glasnik RS, no. 4/2010) is 0.1 mg/kg. On the basis of these results it can be concluded that the examined samples of alfalfa are suitable for feeding animals and do not threaten the food chain, as well as safe food production.