Influence of Cover Crop Termination on Ground Dwelling Arthropods in Organic Vegetable Systems

A key aspect in cover crop management is termination before the cash crop is planted.The aim of this study was to assess the effects of termination methods on ground-dwellingarthropods. The conventional mechanical termination method—i.e., green manuring by means of adisc harrow—was compared to flattening using a roller crimper. Two different crop systems wereinvestigated for two growing seasons; cauliflower was grown in autumn after the termination of amixture of cowpea, pearl millet, and radish, and tomato was cropped in spring and summer after thetermination of a mixture of barley and vetch. Ground beetles (Coleoptera: Carabidae), rove beetles(Coleoptera: Staphylinidae), and spiders (Araneae) were sampled by means of standard pitfalltraps throughout the growing season of both cash crops. The roller crimper increased the overallabundance of ground beetles in the first growing season of both cash crops, whereas in the secondyear, no significant effect could be detected. Rove beetles were more abundant in plots where thecover crops were terminated by the roller crimper. Finally, green manuring increased the abundanceof spiders, especially on the first sampling date after cover crop termination. Albeit different taxashowed different responses, the termination of cover crops by a roller crimper generally increased theabundance of ground dwelling arthropods. Given that most of the sampled species were generalistpredators, their increased abundance could possibly improve biological control