Soil compaction is an important environmental problem and it causes physical degradation by adversely influencing hydraulic properties of soil and productivity parameters. It can affect root development and nutrient uptake. Objective of this study is to determine effects of soil compaction on root development and nutrient uptake of forage crops. Trial was carried out for 3.5 months in PVC cylindrical pots filled with clay loam soils with hairy vetch (Vicia villosa Roth.), common vetch (Vicia saliva L.), Italian ryegrass (Lolium italicum Lam.) and barley (Hordeum vulgare L.) plants. Statistical analyses showed that as the bulk density increased, root length and root surface area decrease (statistically significant in common vetch and nonsignificant in Italian ryegrass and barley). Increase in bulk density caused in all plants a significant decrease (p <= 0.05) in dry weights of root and shoot. Plant generally had lower quantities of nitrogen (N), calcium (Ca), and magnesium (Mg) and higher quantities of phosphorus (P), iron (Fe), manganese (Mn), and zinc (Zn) as the bulk density increased.