This document provides information about sulfur as a plant nutrient. It discusses sulfur's role in plant growth, deficiency and toxicity symptoms, sources of sulfur in soil and fertilizers, and transformations of sulfur in soil. Key points include: sulfur is essential for plant protein synthesis and enzyme activity; deficiency appears as chlorosis on young leaves; sources include soil organic matter, atmosphere, and fertilizers like ammonium sulfate; and transformations between organic and inorganic forms are mediated by microbes.

1. INDIRA GANDHI KRISHI VISHWAVIDYALAYA, RAIPUR (C.G.)
Presentation
On
SULPHUR
Master of Science in Agriculture
Submitted To Submitted By
Dr. V.N. Mishra Dayashankar Baghel
Deptt. of soil science
IGKV Raipur (C.G) M.Sc ( Previous )
Dept. of Ag. Microbiology

2. Introduction of Sulphur
• Sulphur are considered as secondary nutrients for plants was so far discovered by
Salon Horstmas.
• Sulphur is a major constituent of organic matter and involved in enzymic
processes.
• Sulphur is essential in formation of plant protein because it is a part of certain
amino acids.
• It is an essential constituent of several other biologically active compounds such
as vitamins, lipoic acid, acetyl coenzyme A, ferrodoxin and glutathione.

3. Characterstics of Sulphur Nutrients
• Symbol – S
• Element sulphur is a bright yellow
• Non-metallic element
• Atomic number - 16
• Atomic weight - 32.065
• % proportion of earth crust- 0.6 - 0.10%
• Mobility in plants – Relatively immobile

4. Source of Sulphur
• Sulphur consist of earth crust about 0.06% - 0.10%, it occurs as
sulphide in igneous and sedimentary rocks.
• Atmosphere is an another source of Sulphur.
• A considerable amount of Sulphur is released by the breakdown of the
soil organic matter that is 20-30 kg 𝑆𝑂3/ha.
• Sulphur content is also there in organic fertilizers.

5. • Cow and Pig manure contains 1.8 kg 𝑆𝑂3 /t, compost contains around
3.8 kg 𝑆𝑂3t and poultry manure contains around 8.3kg 𝑆𝑂3 /t.
• Some mineral fertilizers also have sulphur content in the form of
sulphate, elemental sulphur and liquid form.
• Acid Rain also provides sulphur.

6. Fertilizers having sulphur content
Ammonium sulphate 24 %
Nitrate Sulphate 5 – 14 %
Calcium sulphate 14 – 18 %
Calcium-Magnesium sulphate 22 %
Magnesium sulphate 25 – 30 %
Potassium sulphate 16 – 22 %
single super phosphate 12 %
Ferrous sulphate 32 %
Zinc sulphate 18 – 22 %

7. Forms of sulphur in soil
Sulphur is present in the soil in both organic and inorganic form.
• Sulphur can be broadly grouped into five forms,
 Organic S.
 Inorganic S.
 Soluble S.
 Insoluble S.
 Adsorbed S.
• Among of these forms Organic Sulphur is most important i.e. 5 to 98% of available S in Indian
soils.

8. Transformation of Sulphur in soil
• All the forms of Sulphur are not available to the crop plants, therefore, its
mineralization is essential to convert unavailable form of S in to available form.
• This transformation/mineralization depends upon several factors,these factors are:
• Microbial activity
• Effect of soil temperature
• Effect of soil pH
• Effect of soil moisture content

9. Transformation cont..
• Transformation of elemental sulphur to 𝑆𝑂4
2−
form was necessary for
sulphur to be available for crop uptake.
• The oxidation was faster in coarse textured soils and is completed in 3-
4weeks.
• Sulphur transformations in soil are considered to result primarily from
microbial activity which involves process of mineralization,
immobilization, oxidation and reduction and the microbes involved are
Thiobacillus , Chlorabium and Desulfovibrio.

10. Sulphur Cycle
• Sulphur from all the sources changes in the sulphate or available form of sulphur.
• The crop plant uptake that available S and some of this lost due to leaching and a considerable
part losses to atmosphere.
• A part of sulphur from the residues of plant and animal losses to atmosphere.
• The sulphur from atmosphere comes down with acid rain.
• In the reduction-oxidation processes, SO4 is the last ion to undergo reduction after all the ions
have been reduced, thus intense reduction conditions are necessary.
• During decomposition of organic matter under normal arable soil conditions, organic sulphur
compounds are oxidized to sulphates.

12. Deficiency Symptoms
• Sulphur deficiency symptoms first appear on younger leaves.
• The younger leaves become light green to yellowish in color.
• Chlorosis in leaf.
• Reduced protein synthesis.
• Nodule formation may be affected also.
• Different plants have different deficiency symptoms like shortened panicle
in Rice, delayed flowering in soybean and less oil content mustard etc.

13. Rice Maize Maize
Soyabean Tobacco

14. Toxicity Symptoms
• leaf size will be reduce
• Overall growth will be stunted
• Yellowing of leaf or scorched at edges

15. Role of Sulphur in plant growth
• Component of amino acids (methionine, cysteine).
• Responsible for pungency and flavour (onion, garlic, mustard).
• Involved in the formation of Chlorophyll and promotes nodule
formation.
• Essential in synthesis of oil in oil seed crops.
• It increases root growth and stimulate seed formation.
• Activation of enzymes.