This document discusses the use of gypsum as a source for soil reclamation. Gypsum is a calcium sulfate mineral that can be used as a fertilizer. It has many beneficial properties for soil including improving compacted soil, decreasing bulk density, preventing crusting and aiding seed emergence. Gypsum also helps plants absorb nutrients, stops erosion, improves soil structure and fruit quality. The document provides the chemical reaction and equations for calculating the gypsum requirement to reclaim sodic soils. It compares the efficiency of gypsum to other amendments and discusses application methods.

1. Gypsum as a source of
soil reclamation
Gajendra meena

2. Gypsum
Gypsum is a soft sulphate mineral composed of
calcium sulphate dehydrate, with the chemical
formula CaSO4. 2H2O. It can be used as a fertilizer.

3. Properties of Gypsum That
Provide Benefits for Agricultural
Uses
• Gypsum Improves Compacted Soil
• Gypsum Decreases Bulk Density of Soil
• Gypsum Helps Prepare Soil for No-Till
Management
• Gypsum Prevents Crusting of Soil and Aids Seed
Emergence
• Gypsum Decreases Loss of Fertilizer Nitrogen to
the Air

4. • Gypsum Helps Plants Absorb Plant
Nutrients
• Gypsum Stops Water Runoff and Erosion
• Gypsum Decreases Dust Erosion
• Gypsum Improves Soil Structure
• Gypsum Improves Fruit Quality and
Prevents Some Plant Diseases

5. • Gypsum Corrects Subsoil Acidity.
• Gypsum has 17% Sulfate.
• Gypsum Helps Reclaim Sodic Soils.
• Gypsum Makes Water-Soluble Polymer
Soil Conditioners More Effective
• Gypsum Makes Magnesium Non-Toxic.

6. • Gypsum Improves Water-Use Efficiency
• Gypsum Makes It Possible to use Low
Quality Irrigation Water
• Gypsum Decreases Heavy-Metal Toxicity
• Gypsum Decreases the Toxic Effect of NaCl
Salinity

7. • Gypsum reaction involving reclimation of
alkaline soil.
• Na2CO3+CaSO4↔CaCO3+Na2SO4↓
• Leachable
• Na
[Clay]Na
+CaSO4↔ Ca
[Clay]+Na2SO4↓
Leachable
• (Das D.K. Introductory of soil sciance pp 259)

8. Gypsum requirement
• The quantity of gypsum required to replace an
initial level of exchangeable sodium(ENai) and
achieve its reduction to a desired level of
exchangeable sodium(ENaf) per unit area and
per unit depth of the soil, can also be
calculated by using Equation

9. • Where ENa and CEC are in cmol per kg
One cmol gypsum/kg soil is equal to 860
kg gypsum/106
kg soil, for one hectare to
depth 0-15 cm
GR( in cmol/kg soil)=(ENai - ENaf) CEC

10. • GR can be calculated by Equation
(ISSS; Fundamental of soil science pp 344)
GR(kg/ha)=1720×( Enai - Enaf ) CEC

11. Estimated efficiency for various materials used to reclaim sodic soils
compared yo gypsum
• Amendment
• Gypsum
• Sulphuric acid
• Sulphur
• Iron sulphate
• Lime sulphur
• Amount equivalent to
1 tone of gypsum
• 1.00
• 0.57
• 0.18
• 1.62
• 0.75

12. • The efficiency of gypsum and other
amendments will depend on the fineness
as well as purity of material, a finenss with
particle size of 2 mm or 0.59 mm( 10 to 30
mesh sieve )

13. Application method of Gypsum
• Normally broadcasted and incorporate in
surface 10-12 cm by the using cultivator.
• avoid deep mixing for prevent reaction
with soluble carbonate, which reduced
efficiency of Gypsum.

14. AMOUNT OF AMENDMENTS REQUIRED TO RECLIAM
SODIC SOIL ON THE BASIS OF EXCHANGEABLE
SODIUM
EXCHANGEABLE SODIUM( Me/100
g soil)
• 1
• 2
• 3
• 4
• 5
• 6
• 7
• 8
• 9
Gypsum t/ha
• 2,12
• 4.25
• 6.50
• 8.62
• 10.75
• 12.87
• 15.00
• 17.12
• 19.37

15. CONCLUSIONS
• Chemical reclamation of alkaline soils, in
developing countries, has recently become too
costly and therefore efforts have been made to
minimize the costs of reclamation.
amelioration of a calcareous saline sodic soil
can be achieved efficiently applying an
amendment
Now a days Gypsum use as a source of
reclamation