MENDELNET 2013 69 | Page DISTRIBUTION OF BARLEY ROOT BIOMASS IN SOIL PROFILE Klimešová J., Středa T. Department of Crop Science, Breeding and Plant Medicine, Faculty of Agronomy, Mendel University in Brno, Zemedelska 1, 613 00 Brno, Czech Republic E-mail: jana.klimesova@mendelu.cz ABSTRACT In 2010 and 2011 was realized a field trial with selected varieties of barley in two localities, Hrubčice and Želešice. In five varieties root system size, its distribution in soil profile layers within 60 cms of depth and grain yield were evaluated. The impact of locality, year and variety on root system attributes was quantified. The amount of root biomass was always influenced significantly by year (up to 43.5%), locality (up to 19.5%) and their mutual interaction. The impact of these factors differed according to the depth of soil profile. In deeper depths the effect of variety also developed. In 2011 statistically significantly higher values of root length density (RLD) were identified in all localities. In shallow layers of soil plants produced more roots in Želešice. Highest values of RLD were determined in the layer of 0 to 10 cm. Tendency to increase RLD in both localities and most varieties in layer of 40 to 60 cm were detected. A significant dependency of grain yield on RLD was only determined in middle layers of the soil profile. In wet year of 2010 a significant negative correlation was determined. A positive relation was recorded in 2011. Key words: barley, root length density, root system, yield, soil profile Acknowledgments: This work was supported by project No. QI111C080.