Uronium hydrogen sulphate

Toxicity to soil macroorganisms except arthropods

Administrative data

Endpoint:

toxicity to soil macroorganisms except arthropods: long-term

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

data from handbook or collection of data

Data source

Reference

Reference Type:

publication

Title:

Long-term effects of nitrogenous fertilizers on grassland earthworms (Oligochaeta: Lumricidae): Their relation to soil acidification

Author:

Wei-Chun Ma., Brussaard, L. & de Ridder, J.A.

Year:

1990

Bibliographic source:

Agriculture, Ecosystems and Environment 30(1-2): 71-80

Materials and methods

Test guideline

Qualifier:

no guideline followed

Principles of method if other than guideline:

Long term fertiliser exposure in earthworms

GLP compliance:

no

Test material

Test material information

Constituent 1

Reference substance name:

Urea

EC Number:

200-315-5

EC Name:

Urea

Cas Number:

57-13-6

Molecular formula:

CH4N2O

IUPAC Name:

urea

Details on test material:

No information available

Sampling and analysis

Analytical monitoring:

not specified

Test substrate

Vehicle:

not specified

Test organisms

Test organisms (species):

other: Oligochaeta and Lumbricidae

Animal group:

annelids

Details on test organisms:

Grassland worms; Oligochaeta and Lumbricidae

Study design

Study type:

field study

Substrate type:

natural soil

Limit test:

no

Total exposure duration:

1 040 wk

Remarks:

20 years

Test conditions

Details on test conditions:

The study began in 1965. Uncultivated turf grass on sandy loam soil, situated near the Institute of Soil Fertility, Haren, The Netherlands. Organic matter content 6.2 - 6.7%. The site was divided into plots according to a randomised complete block design with 2 replications of each treatment. The plots were mowed once or twice a week during the growth seasons and harrowed once a year at the end of the winter period. Lime was added in 1983 to stabilise the pH of the soil.
The fertiliser was applied twice a year, in mid March and at the beginning of August.
Earthworms were sampled in October/November 1985 (at the end of the 20 year exposure period) by hand-sorting of excavated soil blocks 30 cm² x 15 cm deep, followed by extraction from deeper layers using formalin. The earthworms were fixed and kept in 70% ethanol plus 5% formalin. The biomass of preserved worms was detemined.

Nominal and measured concentrations:

Annual rate of 60, 120, and 180 kg N/ha

Results and discussion

Effect concentrations

Duration:

1 040 wk

Remarks on result:

other: Urea fertiliser reduced earthworm numbers and biomass and lowered pH.

Details on results:

Application of nitrogenous fertilisers to grassland for long periods may have a deleterious effect on earthworms in the absence of liming.

Results with reference substance (positive control):

Not examined.

Reported statistics and error estimates:

ANOVA on log transformed data. Differences between means were assessed with the method of LSD.

Any other information on results incl. tables

Urea fertiliser reduced earthworm numbers and biomass and lowered pH.

Applicant's summary and conclusion

Validity criteria fulfilled:

not applicable

Conclusions:

Application of nitrogenous fertilisers to grassland for long periods may have a deleterious effect on earthworms in the absence of liming.

Executive summary:

Effects of long term use of urea fertiliser at 60, 120 and 180 kg N/ha/year was assessed on lumbricid earthworms in uncultivated turfgrass on loamy sand soil. The test sites were treated twice yearly for 20 years. Urea fertiliser reduced earthworm numbers and biomass and lowered pH. It was concluded that application of nitrogenous fertilisers for long periods may have a deleterious effect on earthworms in the absence of liming.