← Elaine Ingham · Research and publications
How the food web changes when one group is targeted
A corn-field experiment examined substances used to reduce particular soil organisms and the interpretation of their responses.
Study published:
The experimental approach
Coleman, Crossley and Ingham tested substances targeting bacteria, nematodes and microarthropods. They examined direct and indirect effects within the soil food web as a tool for studying plant nutrition. [1]
The recorded responses
Bacterial reduction by the tested bactericides was limited. Naphthalene increased fungal activity and biomass. The authors suggested an indirect effect through reduced fungal-feeding organisms as a possible explanation. [1]
An intervention needs checking
Attributing a change to a feeding relationship requires confirming what changed in each group. The experimental method itself affects the system. Assessing that method forms part of the research.
A lesson for our comparisons
Field observations benefit from linking interventions with repeated measurements. Controls and records of conditions support interpretation. We can then follow a change through the food web rather than rely on a single final picture.
Sources and references
- Coleman, D.C., Crossley, D.A., Jr. & Ingham, E.R. (1994). Use of sulfamethoxazole-penicillin, oxytetracycline, carbofuran, carbaryl, naphthalene and Temik to remove key organism groups in soil in a corn agroecosystem. Journal of Sustainable Agriculture, 4(3), 7–30. DOI: 10.1300/J064v04n03_03 Original publication and study record