SOIL SALINITY IN INDIAGEETIKA SALUJA

M.SC Semester-IIIENVIRONMENTAL SCIENCE

INTRODUCTION Soil to mankind is a basic natural resource. Soil

is a mixture of solid, liquid and gaseous substances, forms the top most layer of the Earth’s crust. It has both the abiotic and biotic component.

Soil Complex is form of 5 components: Mineral Matter Soil Organic Humus Soil Water Soil Atmosphere Biological System

SOIL SALINITY IN INDIA The saline soil are the ‘SALT AFFECTED SOILS”

generally found in Arid and Semi-Arid regions. These soils are generally found in “low

precipitation area” where precipitation and evaporation ratio is less than 10.75

Weathering of parent rock also contribute to the soluble salts to soil.

In India about 7 million hectare area produces less yield due to salinity problem.

Picture showing the soil salinity in Rajasthan area

The white, rounded "caps" of the columns are comprised of soil dispersed because of the high sodium saturation

CLASSIFICATION OF SALINE SOIL

The distinguish characteristics of saline soils in India is been found. On basis of their characteristics the saline soil have been categorized into:-

SALINE SOIL SALINE-ALKALI SOIL SALINE-SODIC SOIL CALCAREOUS SOIL

SALINE SOIL

SALINE SOIL contains excess neutral or alkaline salts due to:

Formation of limestone from igneous rocks Nearness of sea shore Ground or canal water irrigation for longer time.They are known by different names in different regionsREH in UTTAR PRADESHTHAR in PUNJABKHAJAR in GUJRATKHAR in MAHARASHTRA

Soil generally contains ‘white or greyish pluffy’.

Texture is sandy or sandy loam.{ Exception: Curry Soil of Kerala which are clayey in texture}

Conductivity of soil is more than 4mS/cm Exchangeable Na% is less than 15 Principal anions are chloride or sulfate

with small quantity of bicarbonates.

Whitish crust of salts exposed at the surface

Saline Alakli Soils They combine characteristics of both

SALINE and Alkali soils Have white incrustations Have both alkaline and neutral salts pH8.5 or more Conductivity more than 4mS/cm

ALKALI-SODIC SOILS Possess blackish or dark brown color due to

formation of complex structure of Na with organic material

These are hard and compact with clayey or clayey loam in texture

There is an excess accumulation of salts of Na and K.

Anions include carbonate ions Exchangeable Na is more than 15% pH8.5-10 Conductivity is less than 4mS/cm

CALCAREOUS SOIL Have high content of Calcium carbonate

and calcium oxide Calcareous soil develop from Limestone

rock Humus and nutrient content is poor but

water holding capacity is moderate.

Calcium carbonate accumulationin the lower B horizon

Extent of Saline and Alakli Soils in India

States Area under saline soil (million hectare)

Uttar Pradesh 1.28 million hectareGujarat 1.2 million hectareWest Bengal 0.84 million hectareRajasthan 0.720 million hectarePunjab 0.68 million hectareMaharashtra 0.528 million hectareHaryana 0.520 million hectareKarnatka 0.400 million hectareOrissa 0.400 million hectareMadhya Pradesh 0.20 million hectare

States Area under saline soil (million hectare)

Andhra Pradesh 0.024 million hectareDelhi 0.016 million hectareKerala 0.016 million hectareBihar 0.004 million hectareTamil Nadu 0.872 million hectareTOTAL 7 million hectare

EFFECTS OF SOIL SALINITY Increase soil salinity levels can greatly

effect plant growth and production. Excess soil salinity causes poor and

spotty stands of crops, uneven and stunted growth and poor yields, the extent depending on the degree of salinity.

The primary effects of excess salinity is that it renders less water available to plants although some is still present in the root zone.

Dwarf Cashew seedlings of close CCP 06 on the 21st day after sowing. Seedlings were

subjected to control(0; 0.7;1.8; 6.0; 9.5; 13.4; 17.4

EFFECTS OF SALINITY ON PHOTOSYNTHESIS

Salinity in plants can have a huge effect on the rate of photosynthesis.

The effects of salt in plants is similar to drought in plants.

Because the salt absorbs the water, in a high enough quantity the salt can dry out plants which makes photosynthesis slow down at a very high rate or even make photosynthesis in plants cease all together.

If too much salt gets into the plant then the stomata, this allows carbon dioxide into the plant, may close up which will not allow and carbon dioxide in or oxygen out.

INTEGRATED MANAGEMENT PRACTICES FOR THE RECLAMATION OF SALT AFFECTED SOILS

Presence of salt-tolerant native plants, such as Red Sapphire

Spraying of the GYPSUM to decrease the salinity of soil

THANK YOU