Erd-Wurzel-Separation nach dem maschinellen Ausstechen von Ampfer (Rumex obtusifolius)

Labour-intensive manual digging with various sorts of spades or forks is the most common technique to control broad-leaved dock (Rumex obtusifolius). Machines for removing roots exist, but are not in use. The process leaves undesired holes in the ground and large quantities of soil have to be removed. An invention for separating the fertile soil from the roots directly in the field and refilling the holes thus created would represent a significant advance. Agroscope Reckenholz-Tanikon ART has developed a separation unit to improve the mechanical weeding process. The separator unit consists of three paired rotary brushes (d = 200 mm,l = 250 mm) and an oscillating sieve (surface: 200 x 500 mm, gaps: 15 x 500 mm). In the summer 2011 a self-propelled unit dug out 174 Rumex obtusifolius plants on grassland on the experimental farm in Tanikon. The cleaned soil was used in situ to refill the holes created. The weight of both the excavated and cleaned soil was recorded. A RTK-GPS device enabled the exact position of plants to be located. Three months after treatment, the treaded places had been evaluated. In 160 cases (92 %) where Rumex plants had been removed at the same positions no plants regrew. The used standard adjustment could separate 55 to 80 % of the total excavation, depend on field condition. Disadvantages are the transport of 1.2 kg of soil and root material per plant in average and high efforts on machine construction.