Effects of calcium cyanamide on Collembola in a standardized field test: Part 1. Rationale and performance of the study

BACKGROUND: A field study lasting one year was performed to study the effects of a calcium cyanamide fertiliser (trade name: Perlka®) on Collembola in order to support the terrestrial risk assessment under the REACH (Registration, Evaluation, Authorisation and Restriction of Chemicals) regulation. Due to the lack of an appropriate guidance document, the design of the study was based on the ISO Guideline 11268–3, originally developed for earthworm field studies. However, the sampling procedure was adapted accordingly by applying ISO Guideline 23611–2, i.e. taking soil core and pitfall trap samples. Two groups of four plots each were treated with 200 kg/ha and 400 kg/ha Perlka®, respectively. A third group served as a fertiliser control, i.e. it was treated with a standard urea fertiliser (172.9 kg Piagran®/ha) at the same total nitrogen rate (79.5 kg/ha) as provided by the high Perlka® application rate. The fourth group served as negative control without any fertiliser treatment and the fifth group was treated with the reference item Agriclor® (480 g a.i./L chlorpyrifos), known to be toxic to springtails. RESULTS: In total 16 different Collembola species were determined. For seven species, covering all life form types, a reliable statistical evaluation was possible, which was reflected in correspondingly low MDD values in the study. A statistically significant decrease of the abundance (at least 50%) on the reference item plots compared to the untreated control was observed for six species, thus demonstrating the sensitivity of the Collembola community. CONCLUSION: No long-lasting effects of the Perlka® application rates could be observed for any of the Collembola species. In order to support risk assessors in both industry and authorities in the interpretation of large and complex data sets typical for field studies with chemicals, further guidance on implementation and data interpretation is urgently needed.