ppt about role of soil sulphur in plants, their toxicity and deficiency symptoms and their corrective measures

1. SULPHUR
HARSHA, M.
PALB7338

2. Introduction
• 4th essential nutrient
• Essentiality given by Sachs and Knop
• Occurs in both organic and inorganic forms (organic form > inorganic)
• Mainly S containing minerals in soil-
Pyrites(FeS2),
Cobaltite(CoAsS),
Gypsum(CaSO4.2H2O),
Epsomite(MgSO4.6H2O),
 Chalcopyrite(CuFeS2),
Sphalerite (ZnS) and sulphate in soluble form

3. Introduction….
• Gaseous forms- SO2 and H2S
• Taken as 𝑆𝑂4
2−
by plants
• Organic sulphur by Biological oxidation
• Sulphate ions reduced to sulphydryl(-SH) groups in plants
• S is Immobile in plant
• Concentration in plant 0.1%

4. Functions
• Synthesis of sulphur containing amino acids cystine, cysteine and
methionine
• Synthesis of protein & Formation of disulphide bonds between
polypeptide chains
• Synthesis of coenzyme A, biotin ,thiamine or vitamin B1 and glutathione.
• Vital part of ferredoxin, non-heme iron sulphur protein in chloroplast
• Synthesis of chlorophyll
• Characteristic smell and taste of plants in mustard ,cabbage ,cauliflower
and onion as polysulfides.
• Activation of proteolytic enzymes like papainase, and synthesis of papain

5. Functions….
• Increase root growth
• Stimulates seed formation
• Promotes nodule formation on roots of leguminous plants
• Part of nitrogenase enzyme system
• Increase oil content in flax, soybean, groundnut
• Sulphydryl(-SH) groups related to increased cold resistance
NITROGENASE

6. Deficiency Symptoms
• Fading of normal green colour of the young meristem followed by
chlorosis
• Shoot growth restricted
• The leaves show cupping , curling
• Older leaves become puckered inwardly with raised areas between the
veins
• Stem and leaves petiole may become brittle and collapse
• Reduced synthesis of protiens and oils
• Low chlorophyll synthesis
• Reduced nodule formation.

7. CORN TOBACCO
DEFICIENCY SYMPTOMS
TOMATO

9. Sulphur deficiency in RICE

10. S deficiency in flowering crop
Maize

12. Toxicity Symptoms
• Rare
• Leaf size and overall growth reduced
• Yellowing of leaves and scorched at the edges
• Induces deficiency of other nutrients by competition
SULPHUR TOXICITY IN
RICE

13. Management of ‘S’ or Correction of ‘S’
Deficiency
• Application of elemental sulphur or gypsum particularly on alkaline
soils
• Application of SSP (12% S) MgSO4 (30%s), NH4SO4(24.2%S)
• On standing crop, foliar application of sulphate salts like ferrous
sulphate(32.8%) and ferrous ammonium sulphate (16%)

14. Management……
• Maintaining high organic matter content- increase the availability of
sulphur to the roots, and decrease the rate of nutrient leaching.
• Burning of crop and fallow residues leads to direct losses of sulphur
to the atmosphere, and loss of organic matter inputs to the soil. This
practice not recommended where sulphur supply is poor.

15. Deseases: Tea yellow, Akiochi
:Akiochi/sulphur red/sulphide injury/H2S injury:
• Found in rice
• In anaerobic condition.
• H2S formed by decay of organic matter
• 𝑆𝑂4
2−
acts as electron acceptor for sulphate reducing
bacteria(Desulphovibrio, Desulphomaculatum), & reduced to H2S
• In rice fields, high in OM & low in elements like Fe, H2S released,
harmful to rice roots, this injury is Akiochi

16. Symptoms of Akiochi
• Upper leaves become progressively
shorter
• Lower leaves drying & dirty yellow with
brown spots on surface
• Roots are pale white, mingled with black
or rotten ones giving rotten egg smell &
turn to reddish colour when roots are
washed and exposed to sun
• Soil pH- 6
• Bubbles come in affected areas

17. Remedies
• Application of S containing fertilizers avoided
• Application of material containing Fe, (laterites or lake mud)
• Provide aeration
• In submerged soil supplied with Fe, H2S removed by reaction with Fe
• FeS2 formed, forms protective coating on roots & prevent rotting

18. N:S ratio
• Def. of S in plant retards its N metabolism leads increase in N in amide
& 𝑁𝑂3
−
forms
• Optimum N:S - 15-16:1 in legumes & 11-12:1 in cereals
• Application of N to soils deficient in S leads decrease in yield
• Absence of adequate S leads to 𝑁𝑂3
−
utilization hampered and
leached
• 10:1 N:S ratio in fertilizer constantly applied will adequately meet S
requirement.

19. THANK YOU