Identification of deep-rooting crop species in arable subsoil by the minirhizotron technique

Summary

Our current understanding of the plant deep root system and its relevance for crop production is limited. A field trial was established in order to monitor the root growth of various deep-rooted crops down to 5 m of soil depth with the minirhizotron technique. Root intensity (RI: intersections m-1) and maximum rooting depth (m) of seven different crop species indicate varying degree of root penetration capacity among the tested crops. Overall, within one season over 89 % of RI was concentrated at 0-1.0 m of soil depth. Sugar beet (1.4 m) as an annual crop showed the most rapid root growth rate (10.6 mm day-1). On average the perennials resulted in 0.7 m of maximum rooting depth (5.6 mm day-1), which indicates their potential to establish deep root systems in coming seasons.