Soil tillage and crop rotation differently affect biodiversity and species assemblage of ground beetles inhabiting winter wheat fields
Latvia University of Agriculture, Faculty of Agriculture, Institute of Soil and Plant Sciences, Liela street 2, LV-3001 Jelgava, Latvia
This paper continues studies on ground beetles (Carabidae) in differently managed winter wheat (Triticum aestivum) fields in Latvia. The main task of those studies was to assess how different soil tillage regimes (ploughing and non-inverse tillage) and different pre-crops (winter wheat and spring rapeseed (Brassica napus) affect assemblage and biodiversity of ground beetles in winter wheat fields. The research was carried out in the Latvia University of Agriculture Research and Study Farm ‘Pēterlauki’ (56°30’39.38’’N; 23°41’30.15’’E) during vegetation season of 2013. The results were compared with the results of similar research carried out at the same place during 2012. Totally 57 ground beetle species were observed in studied fields in 2013. Total species assemblage varied between both consecutive vegetation seasons of the research, however these were minor differences not connected with studied agro-ecological factors. Dominance structure of ground beetle species was significantly different between both vegetation seasons – species which were dominant and subdominant in 2012 became subdominant and dominant one year later, accordingly. Annual effects of soil tillage regime and pre-crop on ground beetle dominance structure also were observed, however some differences were recognized between both vegetation seasons. In case, if weed control was successful, higher ground beetle biodiversity might be observed in ploughed fields pre-cropped with spring rapeseed. Otherwise, significantly higher ground beetle biodiversity may be observed in harrowed soil independently from the pre-crop.