Effect of Genotype and Farming System on Concentration of Mineral Elements in Organically and Conventionally Grown Cereals/ Genotipa Un Saimniekoðanas Sistçmas Ietekme Uz Minerâlvielu Saturu Bioloìiski Un Konvencionâli Audzçtos Graudaugos

About half of the human population suffers from deficiency of mineral elements, mostly iron (Fe) and zinc (Zn). The purpose of the research was to compare the concentration of Fe and Zn in grain of 19 spring barley (in Hordeum vulgare L.) genotypes and the concentration of Zn and manganese (Mn) in grain of 19 winter wheat (Triticum aestivum L.) genotypes grown in organic and conventional management systems during two growing seasons. The average concentration of Fe in barley ranged from 32.51-86.85 mg·kg^-1 and was higher under conventional management (p < 0.001); the effect of genotype was significant (p = 0.014). The average concentration of Zn in barley ranged 16.79-48.51 mg·kg^-1 and was significantly higher under the organic system (p < 0.001); in wheat it was 21.52-29.89 mg·kg^-1 with no difference between the management systems; the effect of genotype was significant (p = 0.03 and p < 0.001 for barley and wheat, respectively). The average concentration of Mn in wheat ranged from 24.63-36.07 mg·kg^-1 and was higher under the conventional system (p < 0.001); significant differences between genotypes were observed (p < 0.001). Barley and wheat genotypes with higher concentrations of the investigated elements were identified for use in breeding for improvement of grain quality. Zn concentration correlated negatively with grain yield and positively with grain protein concentration.