Earthworm niche groupings: The orange lines represent the types and depths of the various burrows.
Study Design
The study design is according to ISO 11268-3:2014 and ISO 23611-1:2018(E).
The experimental design is a dose response with three treatment groups; a negative control (water treated control), a positive control (reference substance) and the test item.
The test is designed as a randomized complete block with at least four replicates for each treatment (10 m * 10 m per plot), with at least 3 m distance between each plot.
Earthworm experimental field design
Sampling
Earthworms are sampled from the soil by combining two different methods:
1. Hand-sorting
2. Allyl-isothiocyanate (AITC) extraction
Identification
Adults and young worms are counted separately.
Adult earthworms are identified to species level.
Young worms which are difficult to identify, a distinction between tanylobous and epilobous is made.