Ammonium hydrogensulphite

Toxicity to terrestrial plants

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

toxicity to terrestrial plants: long-term

Data waiving:

other justification

Justification for data waiving:

other:

Reference 2

Endpoint:

toxicity to terrestrial plants: long-term

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Qualifier:

equivalent or similar to guideline

Guideline:

EPA OPPTS 850.4230 (Early Seedling Growth Toxicity Test)

Principles of method if other than guideline:

The objective of this study was to evaluate the effect of intermediate to high rates of granulated mineral or organomineral fertilizers on onion N uptake, nutrient balance, root growth and water influx. Onions were grown on four natural soils with different concentrations of ammonium sulfate applied. Test duration was 84 days.

GLP compliance:

not specified

Analytical monitoring:

no

Vehicle:

no

Details on preparation and application of test substrate:

Four Quebec soils (specified in table below) were used in this study. Soils were air dried, sieved to 2-mm aggregate size, moistered to 80% of water-holding capacity, transferred to plastic pots (3.2L volume) in amounts of 3.6 - 4.4 kg, depending on bulk density.
Seeds of onion were sown in flats containing moist vermiculate. On the 14th day, four uniform seedlings were transplanted to each pot. To prevent P, K and Mg deficiency, 40 mg P * kg-1 as Ca(H2PO4)2, 90 mg K*kg-1 as K2SO4, and 40mg Mg*kg-1 were mixed with the soils. Hydrated lime was added to the Beaurivage and the St. Jude soils to raise the pH to near 6.5.
Humic peat, containing 600 g H2O * kg-1 wet peat and 13.6 g total N * kg-1 on a dry-weight basis, was ammoniated with 50 g NH3 as ammonia liquor * kg-1 of peat (i.e., 41.2 g NH3-N * kg-1) on a dry weigh basis and pelleted to 2mm granules. Peat-ammonium sulfate pellets were made of the same peat as described above and reagend-grade AS particles of < 1mm diameter. The fertilizers were mixed with soils 4 days before the seedlings were transplanted.

Species:

Allium cepa

Plant group:

Monocotyledonae (monocots)

Details on test organisms:

- Common name: Common onion
- Plant family: Alliaceae
- Variety: Norstar 210B

Test type:

early seedling growth toxicity test

Study type:

laboratory study

Substrate type:

natural soil

Remarks:

4 types

Limit test:

no

Total exposure duration:

84 d

Test temperature:

18 - 22 °C

pH:

5.0 - 6.6

Moisture:

65% relative humidity

Details on test conditions:

TEST SYSTEM
- Test container (type, material, size): plastic pots (3.2 L)
- Amount of soil: 3.6-4.4 kg
- Method of seeding: Seeds of onion were sown in flats containing moist vermiculite.
- No. of plants (retained after thinning): 4 per pot
- No. of replicates per treatment group: 3
- No. of replicates per control: 3

GROWTH CONDITIONS
- Photoperiod: 16:8 light:dark
- Light source: incandescent and coolwhite fluorescent lamps
- Light intensity and quality: 300 µE/m²/s photon flux density at plant height
- Relative humidity (%): 65 %

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : N uptake, root length, water uptake, nutrient balance, dry matter yield

Nominal and measured concentrations:

Nominal: 0 (control), 133, 266, 399, and 532 mg N per kg soil

Reference substance (positive control):

no

Species:

Allium cepa

Duration:

84 d

Dose descriptor:

LOEC

Effect conc.:

513.3 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

other: NH4

Basis for effect:

other: yield (dry weight)

Key result

Species:

Allium cepa

Duration:

84 d

Dose descriptor:

NOEC

Effect conc.:

342 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

other: NH4

Basis for effect:

other: yield (dry weight)

Details on results:

Yield (dry weight per pot) was greatest for 133 mg N per kg soil. An inhibitory effect was found at 399 and 532 mg N per kg soil (corresponding to 513.3 and 685.1 mg NH4 / kg soil), except for the sandy soil where only the 532 mg N per kg soil ammonium sulfate was inhibitory.

Results with reference substance (positive control):

No positive control was included.

Validity criteria fulfilled:

not applicable

Conclusions:

In a 84 d seedling growth toxicity test, seeds of onion (Allium cepa) were grown in 4 different natural soils amended with ammonium sulphate. An inhibitory effect on yield (dry weight) was found at 399 and 532 mg N/kg soil dw (corresponding to 513.3 and 685.1 mg NH4/kg soil), and a NOEC of 299 mg N/kg soil dw (nominal) can be derived, which corresponds to a 84 d NOEC of 342 mg NH4/kg soil dw (nominal) for ammonium.