Nematode Field Study

A field study to assess effects and recovery on non-target soil nematode communities

Non-target soil organisms are important determinants for essential ecological functions of the agro-ecosystem like soil fertility and litter degradation. Applications of plant protection products should not significantly affect population development and community structure of soil organisms like nematodes. A field study on nematodes under Good Agricultural Practice (GAP) is indicated if laboratory studies as well higher tier studies cannot sufficiently prove harmlessness of the plant protection product on non-target soil organisms. The nematode field study allows determining short and long term effects on soil organism communities and the potential for recovery.

Study Design


Test Organisms

nematodes, living in natural populations

Design of the Test Field

The nematode field studies are usually conducted on arable fields. The test item (if desired with multiple rates), a water- or untreated control, and a toxic reference item (e.g. nematicide) are applied with at least four replicates on the test field according to GAP. All plots are arranged in a fully randomized design. The plot size is usually 100 m² (10m x 10m), but can vary depending on the study design. Distance between the plots is at least 3 m and approx. 10 m distance to the fields next to the test site.

Study Details

Nematode are identified to suborder, family or species level depending on the study design.

Application of Test Substances

The application procedure is conducted similar to agricultural practice. The time and frequency of applications follows the intended use of the product taking into account product persistence and possible interception by vegetation. The application of the test substances are carried out with a calibrated movable plot sprayer or granule applicator.

Analytical Verification of the Test Item Application

ibacon offers three methods for verfication:

  • analysis of spray liquid samples taken before test item application
  • determination of the a.i. content in soil samples
  • analysis of spray residues from Petri dishes placed on the test item treated plots during application

Sampling Methods

Nematodes are sampled by soil core sampling (sampling depth 0-10cm). Subsamples are fixed with a formalin solution and extracted from the soil by using a Ludox centrifugation method.

Recording of environmental Conditions

Soil parameter (soil profile, pH, C-content, water holding capacity, particle size composition) and climate data (soil and air temperature, soil humidity, precipitation) are taken throughout the study.


Course of the Study

Nematodes are sampled before the application of the test item and usally four times after application. Duration: 6 -12 months


Data Evaluation

Statistical analysis on single feeding types/taxa is performed using univariate techniques (e.g. Williams test). The effect of the test item on nematodes is statistically analyzed and compared with the control group for each sampling date. Control and reference item treatments are compared separately. Evaluation of the treatment effect on the nematode community is done by using multivariate techniques and performing a principal response curve analysis (PRC).



The nematode field study accepts initial test item effects and usually focuses on the timespan which is necessary to demonstrate recovery. Recovery is considered to have occurred when soil organism numbers are not significantly lower than the control on two consecutive sampling occasions.


Guidelines and Literature

  • ISO 23611-2 (2007). Soil quality - Sampling of soil invertebrates - Part 2: Sampling and extraction of micro-arthropods (Collembola and Acarina).
  • de Jong F.M.W. et al. (2010) Guidance for summarising and evaluation field studies with non-target arthropods. A guidance document of Dutch Platform for the Assessment of Higher Tier Studies Test Organisms. RIVM, Bilthoven, Netherlands.