AMMONIUM SULFATE CAS N°: 7783-20-2

OECD SIDS
AMMONIUM SULFATE
4. ECOTOXICITY ID: 7783-20-2
DATE: 18.04.2006
Reliability:
SITE DESCRIPTION The rice fields are located in the Eastern
Iberian Peninsula, surrounding the coastal lagoon of "La
Albufera" near Valencia, Spain. A detailed description of
the site and of the rice crop cycle is given in the
following references:1) Quesada A, Sánchez Maeso E, and
Fernández Valiente E, 1995. New incubation device for in
situ measurement of acetylene-reducing activity in
ricefields. J. Appl. Phycol. 1, 195-200.2) Quesada A,
Sánchez Maeso E, and Fernández Valiente E, 1995. Seasonal
variation of chemical properties of rice field soils from
Valencia, Spain. Commun. Soil Sci. Plant Anal . 26,
1-19.The text mentions the alkaline condition of soils and
sediments.The field trials were conducted in three
consecutive crop seasons, using plots of 5m x 20m size,
laterally isolated by plastic sheets embedded into the soil
at a depth of 10cm. Ammonium sulfate was applied at 0,
17.5, 35, 70, and 140 kg N ha-1. A basal dose of 100 kg/ha
P2O5 was supplied, as superphosphate, to all plots. A
randomised complete block design with four replicates was
employed. Basal P and N doses were applied as a single
broadcast application and covered by about 3 cm soil, 1-2
days before flooding. After the initial flood, around mid
May, plots were hand sown at 180 kg/ha seed (rice variety
Senia), pre-soaked in tapwater. Grain and straw yield and N
content in plants were determined at maturity.Soil
cyanobacterial population was measured from cores collected
from each plot, at 4-5 weekly intervals throughout the
growth cycle. Four in situ measurements of nitrogenase
activity were made in May, June, July, and September of each
year.
(2) valid with restrictions
incomplete documentation of soil and of treatment regime
Flag:
Critical study for SIDS endpoint
11-MAY-2003 (84)
Type:
Species:
Unit:
Method:
GLP:
Test substance:
Remark:
Result:
Test condition:
122
field
other bacteria: nitrogen-fixing legume bacteria and
nitrogen-fixing blue green algae
Analytical monitoring: yes
other: see Test Condition
no data
other TS: ammonium sulfate as fertiliser, no further details
The result is attributed to the low pH (4.4) of the soil,
which results from ammonium sulfate addition. Toxic metal
ions (e.g. Al) released from soil at acid pH may contribute
to the effect. Soil pH can be increased by liming.
Biological nitrogen-fixing activity was reduced
(nitrogen-fixing legume bacteria) or eliminated
(nitrogen-fixing blue green algae) in soil fertilised with
ammonium sulfate.
exposure period: more than 30 years; 80 kg N/ha applied
annually.
The test site is located 60 degrees N, 17degrees E, near
Uppsala in Central Sweden. The soil is post glacial clay
(35% clay, 35% silt, 21% fine sand). Several organic and
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