The core sampling method was used to investigate over five years the root depth of winter cereal plants on chernozem-like sandy loess soil (over marly tille). The main root zone (.gtoreq. 1 downward root per 10 cm2 on the average) extends to a depth of 35-45 cm for barley and rye and only 20 cm for wheat at normal sowing date and development before the winter months. At the start of shooting, root zone depth is 60-65 cm for all three cereal crops; it reaches 80 cm at the time of ear emergence. Single roots penetrated even deeper into the soil (up to 20 cm more).