Soil tare and relative soil adherence after uprooting sugar beet by a share lifter, a driven rotary-shoe lifter and a grab lifter

The soil tare of sugar beet from wet clay soils should be reduced to lower the cost and prevent some negative effects of soil tare. Commonly used share lifters press the soil onto the sugar beet and, thereafter, the soil adheres strongly to the beet and is difficult to remove from the beet by mechanical cleaning systems. With the objective to reduce adhering-soil tare and soil adherence, a grab lifter (extraction, three variants) and a driven rotary-shoe lifter were compared with a conventional driven polder share lifter in a field experiment on clay soil. Soil tare after quick extraction with a small-pitch, spiral motion was reduced by a factor of 3.8-6.2, depending on the wetness of the soil. Relative soil adherence was reduced by a factor of 1.5. Soil tare after lifting with a driven rotary-shoe lifter was reduced by a factor of 3.7, irrespective of the soil wetness. Relative soil adherence was not reduced. For both uprooting methods, dug losses were slightly higher and superficial beet damage was lower compared to share lifting. While complex engineering and crown fracture hinder practical application of grab lifting, the driven rotary-shoe lifter offers good potential for reduction of soil tare in practice. (C) 2003 Silsoe Research Institute. All rights reserved Published by Elsevier Ltd.