mean root diameter, specific root length, root length and diameter class distribution were heavily influenced by soil bulk density but the soil type did not have any significant effect. Mean root diameter was positively correlated with soil density, showing a 64% reduction with a 25% bulk density increment. the length of different root orders was strongly affected by soil compaction. thus, an increase in soil compaction decreases the proportion of fine roots (diameter 0 and 0.5 mm) wheres the proportion of medium and high diameter roots (between 0.5 and 1.5 mm) was increased with soil compaction (Fig. 1b). these changes in root size class distribution with soil compaction were visually evident (Fig2)