Minor changes in collembolan communities under different organic crop rotations and tillage regimes
An aim of organic farming is to reduce negative impacts of agricultural management practices on physical, chemical, and biological soil properties. A growing number of organic farmers is trying out methods of reduced tillage to save costs, protect humus and to foster natural processes in the soil. Furthermore, techniques like increasing crop rotation diversity and reduced tillage are discussed under the topics of agroecology or ecological intensification also for implementation in nonorganic farming systems.The question arises as to whether these practices are positively impacting on soil ecosystems and whichindicators can be used to describe these impacts. Collembolans are a widely distributed group of the soil mesofauna. They are mainly characterised as secondary decomposers feeding on fungi and other microorganisms. We investigated the influence of different longterm organic crop rotations (mixed farming with animal husbandry versus stockless arable) and the short term effects of two years of different tillage systems (conventional tillage versus reduced tillage) on the abundance, species richness, species composition, and selected species traits (life forms) of collembolan communities. Although not significant, some trends are evident. Species composition of collembolan communities responded to expected alterations in soil moisture mediated by different crop sequences and interannual effects rather thanto different management practices. The proportion of euedaphic collembolan individuals tended to increase in soil environments that offered more stable habitat conditions from increased availability of organic matter.