Influence of tillage system on the weed infestation in a long-term field trial

Abstract

In Germany reduced tillage (without ploughing) increased to nearly 40% of arable land. Without using a plough weed infestation generally rises. Simultaneously the use of herbicides increases. In a long-term field trial in Dahnsdorf (federal state of Brandenburg, Germany) the impact of reduced tillage on weed occurrence and herbicide use is investigated. The use of glyphosate for seedbed preparation is not always necessary, e.g. in the crop year 2010 glyphosate was not used. The use depends on the rate of weed emergence and the precedent crop. For canola the situation is different, volunteer cereal plants had to be controlled by a graminicide in 6 out of 7 years. In the first years weed emergence is determined by the former crop rotation (cash cropping with 67% cereals vs. forage cropping with 50% cereals) and the herbicide strategy. Round about after four years the influence of the reduced tillage appears in case of the dicotyledonous weeds. Emergence of these weeds is promoted by the reduced tillage especially in combination with slightly reduced herbicide amounts (strategy IPS). The species of the dicotyledonous weeds are mainly (about 70%) Viola arvensis, Veronica spp., Stellaria media, Matricaria spp. and Centaurea cyanus. For Apera spica-venti the emergence is mainly based on the weather conditions and the germinative terms in autumn.

Keywords

• Apera spica-venti
• crop rotation
• glyphosate
• plough
• volunteer crop