| Introduction Agricultural cropping systems generally have a limited use of water and nutrients from the soil below 1m depth. However, several plant species have much deeper root systems, and if included in cropping systems, these would allow for exploitation of otherwise unused resources from deep soil layers. In a unique facility consisting of 12, 4m high ‘root towers’ we examined the root development and root activity in different soil layers of different biannual/perennial plant species. Methods Four plant species lucerne (Medicago sativa), rosinweed (Silphium integrifolium), intermediate wheatgrass (Thinopyrum intermedium), and dyers voad (Isatis tinctoria) were grown in soil in large rhizotrons (root towers) (4m×1.2m×0.6 m). Root growth was... |
