AMMONIUM SULFATE CAS N°: 7783-20-2

OECD SIDS
AMMONIUM SULFATE
3. ENVIRONMENTAL FATE AND PATHWAYS ID: 7783-20-2
DATE: 18.04.2006
pelletized 15N labelled ammonium sulfate fertiliser to the
West Bear Brook catchment, from June 1991 until December 1992
(1991: 21 kg N/ha, 1992: 42 kg/ha). This was part of an
experiment involving otherwise unlabelled ammonium sulfate
fertiliser application at the same level, which has run from
1989 to 1996. The nearby East Bear Brook catchment, with no
fertiliser application, was used as a control.
Remark:
Further information on soil characterisation may be
available in Norton et al (1999), in Environmental
Monitoring and Assessment 55 (page not given).
Result:
Analysis of stream water established that the 1.5 year
(1991-1993) cumulative exports of fertiliser-derived
ammonium represented less than 1% of the labelled fertiliser
added to the catchment. Nitrate plus ammonium exports
contained ca. 2 kg N/ha of the 42 N kg/ha
deposited.
Test substance: Commercial pelletised ammonium sulfate fertiliser, enriched
in 15N at the Tenessee Valley Authority laboratory by
dissolution of the pellets in water, addition of (15NH4)2SO4
into the fertiliser solution, and repelletizing the
precipitated, labelled fertiliser.
Reliability: (1) valid without restriction
study well documented and assignable
28-MAY-2004 (41)
Type of measurement: other
Media:
soil
Result: In two soils treated with ammonium sulfate at rates of 0,
25, 50, 100 and 150 mg N/kg ammonium was rapidly converted
to nitrate. In Tifton soil (fine loamy, siliceous, thermic
Plinthic Paleudults) practically all ammonium had
disappeared by day 22, whilst nitrification in Dothan soil,
a fine loamy, siliceous, thermic Typic Hapludults, was much
slower, and almost stopped by day 30. This difference
between soils was probably due to differences in soil pH and
buffer capacity. Tifton soil had an initial pH of 6.8,
wihich is considered to be close to the optimum for
nitrification. In contrast, Dothan soil had an initial pH of
5.5, providing a much less favorable environment for
nitrification. Nitrification in Dothan soil stopped when thepH
approximated a value of 4.5.
Test condition: temperature: 30 °C
test duration: 40 d in quadruplicate
air change: each 2. day
Reliability: (1) valid without restriction
study well documented and assignable
28-MAY-2004 (42)
Type of measurement: other: laboratory study
Media:
soil-air
Remark:
1) This is a static test, so less ammonia will be removed
than in a flow through test.
2) This reference also cites other papers which give ammonia
losses from fertilisers and liquid sludges applied to soils
of up to 60%. The ammonia volatilisation is dependent upon
the pH of the soil and mode of application, with subsurface
application having greatly reduced ammonia loss from soil.
UNEP PUBLICATIONS 71