Veränderung der Effizienz der Regenwurmaustreibung mit Senfsuspensionen im Tagesverlauf

We tested the effect of sampling time on the efficiency of mustard extractions for earthworms in a field study. On an organic experimental farm (alluvial loams; Hennef/Germany) earthworm extractions were started on two consecutive days hourly from 10 am to 5 pm and 6 pm respectively. Significant effects of daytime on extracted earthworm biomass occurred on both days. Maximum biomass was extracted in the early afternoon in each case. Additional pot experiments have shown a significant temperature dependence of the mustard extraction method which at least partially explains the differences in on-site extracted earthworm biomass in the course of the day. We conclude that daytime has to be considered as a factor when using mustard extraction methods. When used in factorial field experiments, the extractions in different field plots should therefore be operated simultaneously

Persistenz bodenphysikalischer Wirkungen perennierender Futterpflanzen mit Pfahlwurzelsystemen

Taprooted crops create large sized biopores in the subsoil which in turn facilitate root growth of following crops. To date it was unclear, over which periods of time biopores created by taproots remain stable. This study based on a long-term field experiment provides evidence that soil physical effects of taprooted chicory are persistent even 6 years after cultivation. Moreover, repeated cultivation of taprooted crops probably has cumulative beneficial effects on soil structure

Kontrolle von Rumex spp. mit Citronella-Öl im Organischen Landbau

Citronella is an oil, extracted from lemon grass species (Cymbopogon sp) and has been identified as a potential burn-down bioherbicide. In greenhouse pot experiments two fractions of dock roots, Rumex obtusifolius and Rumex crispus (light root fraction, LW: 5-12 g root weight and heavy root fraction, HW: 15-30 g weight) were planted. 116 days after planting the mass of the untreated control gave an increase of 600% (LW) and 300% (HW) root mass, respectively. Citronella oil hindered the accumulation of assimilates in the roots showing a slight decrease of the initial root mass. Efficacy of citronella oil was higher as with cutting the leaves. Citronella oil also showed its efficacy to decrease the leaf area of dock plants after application of lower concentrations (12.5%, 25% and 50% of the recommended concentration), rather than their counterparts acetic acid and pelargonic acid

Wie beinflusst unterschiedliche Düngung die Bodenfauna? - Ergebnisse aus dem DüNaMed-Projekt

Edaphische Vielfalt ist eine wichtige Komponente der Bodenbiodiversität und weitgehend unbekannt. Im Rahmen des Projektes DüNaMed wollen wir die Wirkung differenzierten Düngung auf die edaphische Vielfalt untersuchen