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Root systems of one triticale (x triticosecale Witt.) and one barley (Hordeum vulgare L.) cultivar grown for grain or for the dual purpose of winter forage-plus-grain were studied in a Mediterranean climate (Granada, Spain). The aim was to assess the effect of winter forage removal on root systems and to improve the knowledge of cereal root systems under Mediterranean conditions in relation to soil water use. After the forage was removed by clipping at the end of the winter period, cereal roots were shallower and lower in length densities, compared to the unclipped treatment. The largest differences occurred during the clipping-anthesis period and in the upper soil layers. At the end of the life cycle, the differences between the two systems regarding depth, density and dry matter of roots were small or nil. Moreover, there were no differences in total water use between clipped and unclipped cereals.

Under both production systems (grain and forage plus grain), cereals demonstrated variable downward root extension (0.9 to 1.8 m) as a response to the wetting depth. Triticale roots continued growing after anthesis, especially in the deeper soil layers. In spite of that, root systems were not able to extract a notable amount of residual water (25 to 50 mm) apparently available from the subsoil. In semi-arid Mediterranean drylands, cereal root systems with greater phenotypic plasticity (deeper or larger in the subsoil) in response to subsoil water should be of interest in wetter areas or seasons. This does not necessarily imply a larger root system, but rather a root growth pattern with greater root growth in the subsoil.