Ellen Dahlgren, Agriculture Programme – Soil and Plant Sciences
Why carabid beetles? Weed seed predation by carabids can complement mechanical or chemical weed control. How was this done? From 30 fields with three different tillage regimes were carabid beetles, weed seeds on the ground and weed seed bank size sampled. A model was designed with the aim to see if tillage regime was affecting the carabid beetles’ ability to regulate the weed seed bank during one cropping season. What did we learn? We found that in reduced tillage was the seed abundance affected by carabids earlier in the season. In direct seeding showed the model that seeds in June had an impact on carabids and in their turn had carabids an effect on the regulation. A missing pathway with the effects of weed seed bank in March on carabids in July was added. The regulation was anyhow not different between the tillage regimes.