Sulphur (S) is a ubiquitous on earth and statistically S is available in adequate amounts to satisfy globally plant growth. Nevertheless S deficiency is an important nutrient disorder in agricultural production on all continents (Haneklaus et al., 2003). The S biogeochemical cycle of agro-ecosystems involves the processes like mineralization, immobilization, oxidation, reduction, adsorption, desorption and atmospheric S emissions. Das et al. (2012) reported that the organic C and clay play an important role in regulating sulphur availability in some rapeseed-growing soils of Assam. Examination of soils after incubation revealed that the mineralized S was mainly derived from the C-bonded S and non-reducible organic S pool, while the majority of mineralized S under soil S exhaustion by rice was derived from the C–O–S pool (Zhou et al., 2005). The agronomic efficiency and apparent S recovery by wheat-soybean system decreased with an increase in S application, while the percent response increased with increasing in levels of S. Due to S application, the content of available S was found to increase and the increase was more in surface soils than lower layers (Singh et al., 2014). In a pot culture study, the pesticides like endosulfan, dithane M-45 served a detrimental effect on transformation of S, whereas 2, 4-D created a favourable beneficial effect on S transformation in soil environment (Giri et al., 2011). Long-term human intervention markedly changed the molecular- level composition of soil organic S and led to a shift in the apparent oxidation state of organic S from undisturbed grassland soils primarily composed of S moieties in highly reduced and intermediate oxidation states toward managed agro-ecosystems dominated by organic S rich in strongly oxidized or high-valence S species (Solomon et al., 2011). The XANES (X-ray Absorption Near-Edge Structure Spectroscopy) indicated that the long-term FYM application shifted S species composition from highly oxidized towards intermediate oxidization (Boye et al., 2011). Long term studies related to land use changes may help to understand the soil S cycle in cropping and agro-forestry systems and enrich the knowledge about S management (Jiang et al., 2007). Future research should include evaluation of all components of S cycle collaborating with others to asses environmental impact and sustainability of feedstock production.

1. Sulphur biogeochemistry of
agro-ecosystems
Ramesh Kumar Singh
Roll no. 10260
Division of Agronomy, IARI

2. Contents
 Biogeochemistry
 Introduction to S biogeochemistry
 Processes involved in S biogeochemistry
 S Biogeochemistry of agro-ecosystems
 Conclusion
 Future work

3. Study of Biogeochemistry
 Connected to the role of living
organisms in the migration and
distribution of chemical elements in
the Earth’s crust
 Recognizes the importance of the
biology and the geology of a
particular environment in controlling
chemical transformations
 Understanding the role each
component in regulating elemental
cycling

4. Sulphur biogeochemistry
 5th most abundant (by weight) element in the
universe & the 13th most abundant element in
the Earth's crust
 Valence states ranging from +6 to -2
 Mostly found in sedimentary rocks
 Aerobic environments, S weathered from
rocks is converted to its most highly oxidized
form – SO2−
4
 SO4
2− : assimilated by plant and microbial
 SO4
2− can accumulate, as gypsum in
illuviation zones of semiarid and arid soils
Likens, 2002

5. SOM & biomass
R-C-S & R-O-SO4
SO4 in solution
Sulphide (S2-) Oxidation
Reduction
Elemental S
Solution
Sulphide soil
mineral
Solid phase of
soil
Leaching
Desorption
Adsorption
Earth surface
Coal & Fuel
burning
Sulphur gases
SO2, H2S, COS
Volatilization loss
2-
SO2--->SO4
Direct absorption
Fertilizer &
pesticides
Wet & dry deposition
Animal
&
Human
Residue
2- soil
SO4
mineral
Erosion
&
Runoff
S Bigeochemical Cycle in Agro-ecosystem

6. Processes involved in S biogeochemistry in
agro-ecosystem
 Mineralization
 Immobilization
 Oxidation-reduction
 Adsorption-desorption
 Mineral weathering
 Leaching
 Volatilization

7. S pools and fluxes in agro-ecosystem
Input Range S pools Range Output Range
Forest
Atmospheric
deposition
37-50 (kg
S/ha/yr)
Mineral soil S 310-3070 (kg
S/ha)
Seepage 37-41 (kg S/ha/yr)
AdsorbedSO4
2- -S 8-700 (kg S/ha)
Microbial biomass 12 (kg S/ha)
Literfall 4.8-6.3 (kg
S/ha/yr)
Forest floor 20-60 (kg S/ha) Uptake 6.4-7.6 (kg S/ha/yr)
Forest stand 20-60 (kg S/ha) Run-off 21-34 (kg S/ha/yr)
Agricultural land
Atmospheric
deposition
12-21 (kg
S/ha/yr)
Total S in soil 224-1120 (kg
S/ha)
Uptake 13-42 (kg S/ha/yr)
Ground water 0-295 (kg
S/ha/yr)
Leaching 30-80 (kg S/ha/yr)
Mineralization 10-30 (kg
S/ha/yr)
Gaseous losses 0.2-3.0 (kg S/ha/yr)
Wetland
Inflow 3.2 (kg
S/ha/yr)
SO4
2- -S conc. in
water
30-500 (μM SO4
2-
)
Discharge 10-70% (% of input)
Burial sediments 0.03-32 (kg
S/ha/yr)
H2S 0.01-26 (kg S/ha/yr)
DMS 0.004-1.8(kg S/ha/yr)
Haneklaus et al., 2003

8. S deficiency in Indian soils
S deficiencies are a critical problem in 40-45% of districts of the country
S deficiency covers 57-64 mha of net sown area
The deficit to the tune of 1 mt/annum
http://www.sulphurindia.com/link3.html
70
60
50
40
30
20
10
0
Northern Region
(15323)
Western Region
(12474)
Eastern Region
(10108)
Southern Region
(11289)
All India (49194)
Low Medium High
% deficient soil samples

9. Literature search
Key words: sulfur biogeochemistry, agroecosystem, India

10. Selected literature
S. No. Country Author (s) Name Journal
1. United Kingdom Hendrik Schafer, Natalia Myronova & Rich
Boden
Journal of Experimental Botany
2. India Indranil Das, A. Datta, Koushik Ghosh, Sourov
Chatterjee &A. Chakraborty
Archives of Agronomy and Soil Science
3. China Y. Jiang, Y. Zhang, W. Liang Agricultural Journal
4. Columbia Dawit Solomon, Johannes Lehmann, Katrin
Knoth de Zarruk, Julia Dathe, James Kinyangi,
Biqing Liang & Stephen Machado
Journal of Environmental Quality
5. Sweden K . Boyea , G. Almvist, S. I. Nilsson, J. Eriksen
& I . Persson
European Journal of Soil Science
6. China Wei Zhou, Ping He, Shutian Li, Bao Lin Geoderma
7. Thailand N. Janjirawuttkul, M. Umitsu & S.
Tawornpruek
Internation Journal of Soil Science
8. India K.N. Das, Anjali Basumatari & Bikram
Borkotoki
Journal of the Indian Society of Soil Science
9. India Pradip Kumar Giri, Mintu Sahab, Murari
Prasad Halder & Debatosh Mukherjee
International Journal of Plant, Animal and
Environmental Sciences
10. India S.P. Singh , Room Singh , M.P. Singh & V.P.
Singh
Journal of Plant Nutrition
11. Denmark Jorgen Eriksen Soil Biology & Biochemistry
12. Sweden K. Boye, J.Eriksen , S. I. Nilsson &
L. Mattsson
Plant Soil

11. S biogeochemistry of agro-ecosystems
 S biogeochemistry in upland soils
 Pedogenesis
 Land use/cropping
 Fertilization/residue management
 Pesticide application
 S biogeochemistry in flooded soils
 S emission

12. Effect of pedogenesis on
sulphur biogeochemistry

13. Reservoirs of S near the surface of the Earth
Reservoir 1018 g S
Atmosphere 0.0000028
Seawater 1280
Dobrovolsky (1994)
Sedimentary rocks
Evaporites 2470
Shales 4970
Land plants 0.0085
Soil organic matter 0.0155
Total 8720

14. Pedogenesis of acid sulphate soil
Sampling site and distribution acid sulphate soil in Thailand
Janjirawuttkul et al., 2011

15. A model of 15 soil profiles
Janjirawuttkul et al., 2011
Profile A: Post-active acid sulphate soil
Profile B: Deep potential acid sulphate soil
Profile C: Non-acid sulphate soil
Profile D: Shallow potential acid sulphate soil

16. Physical analysis by optical micrograph
Janjirawuttkul et al., 2011
2Cg in L3 profile
Bjg2 in L3 profile
BCjg in L4 profile

17. Chemical composition
Janjirawuttkul et al., 2011
Profiles
Pyrite (%)

18. X-ray diffraction study of acid sulphate soil
Bjg1 of L4
Bjg2 of L11
Bg3 of L12
ACg of L4
Janjirawuttkul et al., 2011

19. Sulphate sorption/desorption behaviour of S deficient soils of WB
Hysteresis curves of sulphate sorption/desorption
Das et al., 2009

20. Sulphate sorption/desorption behaviour of S deficient soils of WB
S added
to the
soil
(mg/l)
Quantity intensity parameters during sorption run
Toofanganj
Aeric Haplaquept
Debagram
Fluventic Ustochrept
Kaliagang
Typic Fluvaquent
Pundibari
Typic Ustorthent
SP EBC SP EBC SP EBC SP EBC
30 2.80 0.945 2.36 1.17 2.96 0.765 3.25 1.06
45 3.76 0.595 3.39 0.998 4.16 0.625 4.86 0.820
60 3.84 0.425 4.23 0.826 4.94 0.508 5.90 0.634
75 5.88 0.298 5.16 0.708 5.88 0.425 6.88 0.504
Quantity intensity parameters during desorption run
30 1.76 0.558 1.08 1.48 2.38 0.802 13.86 1.49
45 1.98 0.461 1.55 1.16 3.58 0.656 16.51 0.903
60 2.29 0.302 1.73 0.996 3.56 0.627 17.31 0.814
75 2.25 0.307 2.24 0.929 4.08 0.589 18.20 0.736
Das et al., 2009
SP: Supply parameter
EBC: Equilibrium buffering capacity

21. Effect of land use on sulphur
biogeochemistry

22. Profile distribution of S under different land use
Land use: Paddy field (>14 yrs), maize field (14 yrs), fallow field (9 yrs) &
woodland (Poplur, 14 yrs)
Soil total S content under different land uses (g/kg)
Paddy field Maize field Fallow field Woodland
Jiang et al., 2007
0.5
0.45
0.4
0.35
0.3
0.25
0.2
0.15
0.1
0.05
0
0 to 5 5 to 10 10 to 20 20 to 30 30 to 40 40 to 60
Soil total S (g/kg)
Soil depth (cm)

23. Relationships of Soil Total Sulphur (STS) with organic carbon (SOC)
Land use Regression model R square (p=<0.01)
Paddy field STS=1.077 × 10-3+2.239 × 10-2SOC 0.894
Maize field STS=5.301 × 10-2+1.709 × 10-2SOC 0.833
Fallow field STS=4.776 × 10-2+1.525 × 10-2SOC 0.974
Woodland STS=8.004 × 10-2+1.282 × 10-2SOC 0.953
Soil total S storage under different land use
Soil depth (cm) Jiang et al., 2007
S Storage (t/ha)

24. Soil available S content under different land use
Jiang et al., 2007
Soil available S (mg/kg)
Soil depth (cm)
70
60
50
40
30
20
10
0
Paddy field Maize field Fallow field Woodland
0 to 5 5 to 10 10 to 20 20 to 30 30 to 40 40 to 60

25. Sulphur fractions & S availability index (SAI)
in some Rapeseed-growing soils of Assam
District Total S Organic S Non-SO4-S Adsorbed S Available S SAI
Golaghat 614 399.9 170 19.5 37.3 16.3
Jorhat 573 379.9 159 17.8 33.8 15.1
Sibsagar 444 310.0 100 12.0 27.7 10.8
Dibrugarh 552 441.7 80.6 5.10 29.8 12.9
Das et al., 2012

26. Effect of land use on organic S speciation result by XANES
Solomon et al., 2011
Undisturbed
grassland since 1880
Undisturbed
grassland since 1931
Cultivated since 1880
Total organic S (%)

27. Sulphur biogeochemistry as affected
by fertilization & residue management

28. Specific 35S-activity (% of recovered 35S per mg S) in rye grass biomass and soil fraction
Shoots at 1st (dark grey) and 2nd (light grey) harvest, stubble (white), roots (black)
Plant
Fo: Silt loam, Or: Sandy loam
-S FYM -S CR +S FYM +S CR
Sol-S (white with black dots), Org-non prot. S (light grey with black dots), Org-prot. S (dark grey with black dots)
& residual S (black with white dots)
Soil
-S FYM -S CR +S FYM +S CR
Boye et al., 2010

29. Net flow of soil S in soil-plant system (mg S/kg dry soil)
Soil Treatment Inorganic to
plants S
Organic to
plant S
Inorganic to
Organic S
Silt loam (Fo) FYM 0.2 4.1 0.2
CR 0.1 3.0 0.1
Sandy loam
(Or)
FYM 3.0 6.7 1.8
CR 1.3 4.8 0.6
Boye et al., 2010
CR- Crop residue
FYM: Farm yard manure

30. S mineralisation and immobilisation over 5 days incorporation
of plant materials
Eriksen et al., 2005

31. Relationship between C:S ratio & lignin on S transformation over
5 days of residue incorporation
Eriksen et al., 2005

32. Model spectra of S species under organic amended soil
FYM Crop residue
Soil (solid black)
Unprotected S (light grey)
Protected S (dark grey)
Residual S (dashed black)
Boye et al., 2011

33. Agronomic efficiency (AE), apparent S recovery (ASR) & %
response in wheat-soybean cropping sequence
Singh et al., 2014
AE, ASR & % Response
S levels

34. Vertical distribution of S after harvest of wheat & soybean
Wheat
Soybean
Singh et al., 2014

35. Effect f Pesticides on sulphur
biogeochemistry

36. Effect of pesticides on available sulphur content in soil
Effect of pesticides on the population of thiosulphate oxidizing bacteria
Giri et al., 2011
CFU x 103/g soil Available S (mg/kg)

37. Effect of pesticides on aryl sulphatase activity (n kat 100/g) in soil
Treatments
Days after incubation
5th 10th 15th 30th 60th 90th
Control 2.34 2.52 2.81 3.07 3.46 3.16
Endosulfan 1.86 2.14 2.42 2.91 2.79 2.64
Diathane M-
45
2.36 3.01 3.39 3.41 3.14 2.97
2, 4-D 2.51 3.12 3.21 3.68 3.94 3.86
Relationship between R2
Available sulphur vs aryl sulfatase activity 0.97
Available sulphur vs thiosulphate oxidizing bacteria 0.98
Aryl sulfatase activity vs thiosulphate oxidizing bacteria 0.98
Giri et al., 2011

38. Sulphur biogeochemistry of
Flooded agro-ecosystem

39. Mineralization of organic S in flooded paddy soil
Site description:-
Place: China
Climate: Temperate
Soil No. Soil Texture pH
Organic C
(g/kg)
Total S
(mg/kg)
1 Black
soil
Loam 6.2 16.8 316.6
2 Black soil Clay 6.7 19.6 373.0
3 Red soil Loamy clay 5.8 9.1 164.2
4 Red soil Clay 5.5 10.4 195.0
Zhou et al., 2005

40. S mineralization in incubated paddy soil
Incubation period in week Incubation period in week
Incubation period in week
Cumulative mineralized S (mg/kg)
Cumulative mineralized S (mg/kg)
Sulphate-S OI-S
TI-S
Zhou et al., 2005
OI-S: other inorg.S
TI-S: total inorg. S
Cumulative mineralized S (mg/kg)

41. Changes in soil S pools in incubated flooded paddy soil
Zhou et al., 2005
C-O-S: ester sulphate
NRO-S: non reducible org.-S

42. Changes in soil S pools under soil S exhaustion by rice
Zhou et al., 2005
C-O-S: ester sulphate
NRO-S: non reducible org.-S

43. Effect of sulphur emission
on sulphur biogeochemistry

44. Microbial degradation of DMS & related C1-S compound
Importance:-
• Dimethylsulphide (DMS) plays a major role in the global sulphur cycle
• Important implications for atmospheric chemistry, climate regulation, and
Sources of DMS:-
1. Marine environment
2. Terrestrial sources
• Soils may also emit volatile organic sulphur compounds, including DMS, and fluxes
can be enhanced by waterlogging
• The decomposition of plant residues in soil, especially those of crucifer species with
a high content of sulphur-containing glucosinolates, can generate a number of volatile
sulphur compounds
3. Production by plant
4. Anthropogenic sources
DMS emission into the atmosphere is a source of heat-reflecting aerosols that can
sulphur transport from the marine to the atmospheric and terrestrial
environments
serve as cloud condensation nuclei and thereby affect the radiative balance of the Earth,
thus linking DMS production to climate regulation. Atmospheric transport of DMS and its
oxidation products and deposition in the terrestrial environment provides an important link
in the global sulphur cycle.
Major pathways of DMS production and
transformation in the marine environment
Schafer et al., 2010

45. Sinks for DMS
Microbial metabolism of DMS
Three principle:-
(i) Utilization of DMS as a carbon and energy source
(ii) Oxidation to DMSO by phototrophic or heterotrophic organisms
(iii) Utilization as a sulphur source
Schafer et al., 2010

46. Phylogenetic tree
Depicting the genetic diversity of bacterial isolates capable of assimilating carbon from DMS
(overlaid in pink) or degrading DMS to DMSO (green). Schafer et al., 2010

47. Conclusion
 Woodland have the potential to make a significant contribution to soil total
S storage as compared to cropping
 The majority of mineralized S was derived from the C–O–S pool by rice
plant under flooded condition
 Higher hystersis effect was more for S deficient soils, (i.e. Aeric
Haplaquept and Typic Ustorthent soil) adequate S fertilization is needed to
ensure optimum plant growth and yield
 The AE and ASR by wheat-soybean system decreased with increase in S
application, while the percent response increased with increase in levels of
S
 Conversion of undisturbed grassland towards cultivation leads to formation
of strongly oxidized S

48. Future work
 Challenge of optimizing S availability & use efficiency in cropping systems in
synchrony with plant demand and in the required form and quantity
 The emission of DMS from terrestrial and freshwater sources has not been
studied as intensively as that from the marine environment
 Future research should include evaluation of all components of S cycle
collaborating with others to asses environmental impact and sustainability of
feedstock production.

49. Thank you