1. Sulfur has an atomic weight of 32.06
4 rare isotopes 33S, 34S, 35S and 36S can be used for tracing.
2. . . . sulfur is a devilish substance . . . Discharged from the bowels of the earth,
by volcanoes or evil-smelling hot springs . . . Surely the effluent of Hell itself.
– J.R. Postgate
3. Why is S important ?
• Essential element required in relatively high
concentrations by plants and animals
• Essential component of 3 amino acids
– cysteine, cystine, methionine
• Disulfide bonds give structure to many proteins
• Source of metabolic energy for many bacteria
• Postive and negative environmental impacts
– Macronutrient
– Acid mine drainage, acidic deposition
5. Acidic deposition (aka acid rain) killed many
of the trees in this forest
Looks great but
may be devoid of
life if acidity has Monument getting
released toxic
levels of Al dissolved by acid rain
7. Similarities with the N cycle
Many oxidation states
Most of the S in soil is a component of SOM
Biological transformations are important
e.g., mineralization and immobilization
Volatilization is a major loss pathway
8. S has lots of oxidation states
Sulfides, -2 Sulfide ion S2-, bisulfide ion HS-,
hydrogen sulfide H2S, carbon-
bonded S
Polysulfide, -1 Disulfide ion S22-, pyrite (FeS2)
Elemental S S0
Thiosulfate, -2 & +6 Thiosulfate ion S2O32-
Sulfites, +4 Sulfite ion SO32-, sulfur dioxide
SO2
Sulfate, +6 Sulfate ion SO42-, sulfuric acid
H2SO4
9. Only reduced forms of S (e.g., sulfides and
elemental S) have acid forming potential.
Rates of elemental sulfur required to decrease soil pH to a depth of 6 inches
Application rate based on soil texture1
Desired change in pH Sand Silt loam Clay
----------------------- lb S/A ----------------------
8.5 to 6.5 370 730 1460
8.0 to 6.5 340 670 1340
7.5 to 6.5 300 600 1200
7.0 to 6.5 180 360 720
8.5 to 5.5 830 1660 3310
8.0 to 5.5 800 1600 3190
7.5 to 5.5 760 1530 3050
7.0 to 5.5 640 1290 2580
1 Assumptions—cation exchange capacity of the sandy loam, silt loam, and clay soil are 5, 10,
and 20 meq/100 g, respectively; soils are not calcareous.
http://ohioline.osu.edu/agf-fact/0507.html
10. Differences with the N cycle
Very little S in the earth’s atmosphere naturally
(most of the S in the atmosphere today is anthropogenic)
Weathering of rocks is the primary source
Most global S in the earth’s crust
Soil concentrations range from 10s to 1000s of ppm
11. Sulfur Forms in Soils
• > 90% of total S in most soils is organic
• Inorganic S
– Sulfate dominates (SO42-) in aerobic soils
– Sulfides (S-2, flooded conditions)
– Elemental S
– Thiosulfates (S2O32-)
– Range in oxidation states (-2 to +6)
12. There are many strong smelling biogenic S compounds
Compound Formula Atmospheric Production
concentration (Tg y-1)
Hydrogen sulfide H 2S 0.2 – 1 ppb 16.5 – 70.6
Sulfur dioxide SO2 0.2 – 5 ppb 15.0
Carbon disulfide CS2 0.1 – 0.4 ppb 3.8 – 4.7
Carbonyl sulfide COS 0.2 – 0.6 ppb 2.7 – 3.5
Methyl mercaptan CH3SH added to natural gas
Ethyl mercaptan CH3CH2SH
Dimethyl sulfide CH3SCH3 58 ppt 39.6 – 45.4
Dimethyl disulfide CH3SSCH3 1.3 – 3.4
"smell of the sea"
13. Wet and dry S deposition is monitored throughout the US
http://www2.nature.nps.gov/air/Monitoring/drymon.cfm
14.
15.
16. Sulfur emissions in Wisconsin over the last 2 decades
Why did S
emissions
decline?
17. The Cap and Trade Success Story
"Cap and trade" programs harness market forces to
achieve cost-effective environmental protection. Markets
can achieve superior environmental protection by giving
businesses both flexibility and a direct financial incentive
to find faster, cheaper and more innovative ways to
reduce pollution.
Cap and trade was designed, tested and proven in
the United States, as a program within the 1990 Clean
Air Act Amendments. The success of this program led
The Economist magazine to crown it "probably the
greatest green success story of the past decade."
(July 6, 2002).
20. Sulfur deficiencies are increasingly
common for 4 main reasons
- Clean air standards have reduced SOx emissions
from power plants and industry by
> 50% in the last 2 decades
- The S contents of fertilizers currently used in the
US are far lower than those used historically.
- Higher crop yields are removing higher amounts of
S from soils as well as increasing the need for S.
- Increased adoption of conservation tillage resulting
in slower mineralization of organic S
23. Relationship between tissue S and yield
Some species like brassicas and sugar beets have much higher S requirements
http://www.eplantscience.com/botanical_biotechnology_biology_chemistry/plant_nutrition/essential_elements_macronutrients/sulfur/assessment_of_critical_nutrient_values.php
24. Typical crop uptake and removal values for S
total uptake harvest residue
crop yield lbs/ac lbs/ac lbs/ac
cabbage 15 tons 71.0 33 38
canola 60 bu 68.0 20.4 47.6
alfalfa 8 tons 43.2 43.2 -----------
onion 30 tons 36.7 28.3 8.4
soybean 50 bu 35.0 23 12
sugar beet 35 tons 29.8 15.8 14
corn grain 180 bu 27.0 14.4 12.6
sunflower 2500 lbs 21.3 6.25 15
wheat 80 bu 19.2 8 11.2
Adapted from http://www.soil.ncsu.edu/publications/Soilfacts/ag-439-16W.pdf and other sources
25. IL Agronomy Handbook guidelines
Soil test S (lbs/A) RATING
0 - 12 Very low
12 - 22 Low
Response
> 22
unlikely
Correlation between yield increases and soil test S is low,
indicating that soil test S does not reliably predict need for S.
When soil test S levels are above 22 lbs /acre, it is very unlikely
that a response to applied S will occur.
When soil test S levels are below 22 lbs/acre, response to applied S is
more likely (but not predictable).
26. The S guidelines in the IL Agronomy
Handbook are derived from experiments
conducted across Illinois in the late
1970s that only identified 5 locations out
of 82 where corn responded to added S.
Hoeft, R.G., J.E. Sawyer, and R.M. Vanden
Heuvel. 1985. Corn response to sulfur on Illinois
soils. J. of Fert. Issues 2:95-104
27. Soil test S levels are declining
In 2009, 13% of 2.5 million samples tested less than 12 lbs/ac Mehlich3 S
(or equivalent) compared to only 4 percent testing below this level in 2005.
Some of the highest frequencies of low S occurred in the western Corn Belt
and central Great Plains.
29. Sulfur Deficiency in Corn
Unlike N,
S is not
readily
Overall light green
remobilized color, worse on new
from older to leaves during rapid
younger growth.
plant parts.
30. Sulfur Deficiency in Wheat
Overall light green color, worse on
new leaves during rapid growth.
31. Important S concepts
When S is deficient, plants tend to accumulate non-
protein N, which raises the N/S ratio in the plant. A N/S
ratio of 9:1 to 12:1 is especially important in forages
that will be used for animal feed, so that the rumen
microorganisms can effectively use the N.
Grasses are more able to utilize sulfate (SO42-) than
legumes, grasses will tend to crowd out the legumes
in S deficient pastures. Rhizobia need S to fix N.
Some plants, like mustard and onion, get their smell
and taste from the presence of S compounds.
32. Sulfur is a key factor limiting the amount of
corn by-products that can be fed to cattle.
Sulfur levels of most corn by-products can range from 0.4 to
0.9% S on a dry matter basis. Some liquid by-products have
been tested as high as 1.5 to 2% S. Sulfur is added during both
the wet and dry corn milling process, so the by-products contain
additional levels above that concentrated from the original corn.
Although it is based on limited research in cattle, the NRC
recommends a maximum tolerable level of 0.4% of the ration dry
matter for sulfur in the ration. Using that recommendation as a
guide the maximum level of corn by-products would range from
30% of dry matter intake at high sulfur levels to over 70% at low
levels, based strictly on the S content
33. So how many lbs of ammonium sulfate should be
applied if your goal is 10 lbs of S?
So what can you apply if your soil needs S?
Ammonium sulfate (21-0-0-?S)?
Ammonium thiosulfate (12-0-0-26S)
Potassium sulfate (0-0-50-18S)
Sul-Po-Mag (0-0-22-11Mg-23S)
Gypsum (0-0-0-23Ca-17S)
Elemental S – 100% S (ES95, ES90, ES85)
Animal manures – 0.4-0.7% S (on a dry basis)
What is the sulfur content of ammonium sulfate?
Chemical formula = (NH4)2SO4
Molecular weight = 132.1 g/mol
Atomic weight of S = 32.1 g/mol
32.1/132.1*100 = 24% S
36. ATS = 12-0-0-26S
When mixed with other fluid
fertilizers and applied as a
concentrated band, ATS can
enhance micronutrient
availability, inhibit urease
activity, inhibit nitrification and
improve availability of P
ATS is a weak inhibitor compared
to N-Serve and Agrotain
37. ATS = 12-0-0-26S
When mixed with other fluid
fertilizers and applied as a
concentrated band, ATS can
N loss (lbs/ac)
enhance micronutrient
availability, inhibit urease
activity, inhibit nitrification and
improve availability of P
ATS is a weak inhibitor compared
to N-Serve and Agrotain
38. Ca and S contents of gypsum samples
Theoretical
Synthetic Natural Cast Drywall
analysis of
Element gypsum gypsum gypsum gypsum
Ca(SO4)*2H2O
(%) (%) (%) (%)
(%)
Calcium 23.3 23.0 19.1 22.4 21.9
Sulfur 18.6 18.7 15.1 19.3 18.1
http://ohioline.osu.edu/anr-fact/0020.html
39. Wet flue gas
desulfurization
Gypsum
http://www.fgdproducts.org/LimeStoneForcedOxidation.htm
46. We are looking for volunteers throughout Illinois
to participate in on-farm research to measure corn response
to sulfur fertilization. The better coverage of the state we can
achieve, the greater our ability will be to predict where sulfur
applications are most needed.
We are especially interested in light-colored soils (less than
2% organic matter, coarse texture, or both) and soils with an
eroded phase. However, we would like to characterize sulfur
response across Illinois, so we will also consider other more
"traditional" soils. Fields that have received manure or sulfur
applications within the last five years will not be considered.
Collaborators will follow a simple design applying 0 and 30 lb
S/acre as a broadcast application in a uniform portion of the
field. Three to eight replications are needed for each field.
47. Sulfur sources and application timing
Sulfur sources will be limited to ammonium sulfate (NH4)2SO4
(21-0-0-24S); MicroEssentials sulfur 15% (13-33-0-15S); and
elemental sulfur (0-0-0-90S). Elemental sulfur should only be
used as a last resort because it often does not become fully
available during the year of application.
If the sulfur source contains other accompanying nutrients,
the corresponding rates of those nutrients will need to be
applied to 0 lbs/ac S strips to avoid a differential response to
nutrients other than sulfur.
The preferred application time is spring, but if the only time
available is fall, we can accommodate that. What is most
important to us is to include as many locations as possible
throughout the state.
48. Treatment options
Ammonium sulfate (21-0-0-24S)
For strips with 30 lb S/acre, apply 125 lb ammonium sulfate/acre. For
the strip with 0 lb S/acre, apply 26 lb N/acre. This application is to
balance the N applied along with the S in the sulfur strip. Those 26 lb of
N/acre can be applied as either 57 lb urea/acre, 94 lb UAN (28%)/acre
(8.7 gal/acre), or 82 lb UAN (32%)/acre (7.4 gal/acre). Do not use
anhydrous ammonia because it would be difficult to apply only 32 lb of
product per acre.
MicroEssentials MES15 (13-33-0-15S)
For the strips with 30 lb S/acre, apply 200 lb MES15/acre. For the strip
with 0 lb S/acre, apply 145 lb DAP (18-46-0)/acre. This application is to
balance the N and P applied along with the S in the sulfur strip.
Elemental sulfur (0-0-0-90S)
For the strip with 30 lb S/acre, apply 33 lb elemental S/acre. For the
strip with 0 lb S/acre, there is no need to apply any product because the
S source is not accompanied by any other nutrient.
49. The only data collaborators will be
expected to provide is the yield for each
strip. This information can be collected
by yield monitor or from a weigh wagon.
Volunteers will not be required to collect
plant or soil samples but must be open to
field visits by U of IL staff several times
during the growing season.
51. Results from on-farm plots in 2010
Site 4 was an Onarga Site 10 was a
sandy loam in central IL Milford silt
– response to added S loam in east-
= 50 bu/ac central IL –
response to
added S
= 21 bu/ac
52. Only one out of 6 IL research station sites
observed any differences between S sources
All fertilizer materials were spring applied
Elemental S and gypsum can be good sources of S
but require more time to become plant available
54. TSI is committed to being the
global advocate for sulphur,
representing all stakeholders
actively engaged in producing,
buying, selling, handling,
transporting, or adding value to
sulphur.
55. The USA and Canada are global leaders in S production!
57. Most S is recovered during
gas and oil refining
58.
59. Sulfuric acid is reacted with rock phosphate
to produce phosphoric acid which is then
used to make DAP, MAP and APP
60. If ammonium sulfate fertilizer costs $400/ton
and we assume the N is worth $0.50/lb, what is
the value of the S ($/lb)?
AMS = 21-0-0-24S
0.21 * 2000 = 420 lbs of N * $0.50/lb = $210
$400 - $210 = $190
0.24*2000 = 480 lbs of S
$190/480 lbs of S = $0.40/lb of S
