Organic farming and moderate tillage change the dominance and spatial structure of soil Collembola communities but have little effects on bulk abundance and species richness

Organic farming technologies are increasingly being used to reduce environmental pollution and grow environmentally friendly products. An integrated approach to assessing the effectiveness of these technologies requires studying the reaction of various components of agroecosystems, including soil fauna. Collembola (springtails) are among the most abundant soil arthropods that regulate nutrient cycling in crop fields. However, the effects of different management types on Collembola communities are context-dependent, and spatial organization of these communities remains unexplored. Here, we studied winter wheat fields in European Russia using a large spatial sampling including 486 samples which were arranged in a nested fractal pattern and grouped into 18 meter plots across six agricultural fields. We compared fields with organic farming (no mineral fertilizer and pesticide applications, moderate tillage) with conventional farming ones. To account for spatial configuration of the sampling design, we applied generalized linear mixed-effects models. The organic farming with moderate tillage changed the structure of Collembola communities by reducing the effect of species over-domination. However, the total abundance and species richness of Collembola was only little and often non-significantly higher under organic than in under the conventional management type. The applied multiscale approach revealed larger spatial aggregations in Collembola communities in organic than in conventional management. Overall, we showed that the effect of organic farming technologies changes taxonomic and spatial structures of Collembola communities, rather their bulk characteristics, such as density and abundance. Functional consequences of these changes are yet to be discovered.