Dr . Mohinder Singh Faculty of Agricultural

Sciences SGT University, Gurgoan

9466310014

Water Logging:Water logging is the natural flooding and over-irrigation that brings water at underground levels to the surface. As a consequence, displacement of the air occurs in the soil with corresponding changes in soil processes and an accumulation of toxic substances that impede plant growth

The actual depth of water table, when it starts affecting the yield of the crops adversely, may vary over a wide range from zero for rice to about 1.5 meters for other crops

Height of capillary fringe

Type of crop

PICS CROPS DEPTH OF WATER TABLE (m)

wheat 0.9 to 1.2

Cotton 1.5 to 1.8

Rice 0.6

Sugarcane 0.9

Fodder crop

1.2

Absence of aeration of soil in the root zone of the plants

Difficulty in cultivation operationsGrowth of water weeds & wild aquatic plantsRise of salts in surface layersRestricted root growthLower soil temperaturePlant diseases

Inadequate surface Drainage Seepage from canal system Over irrigation of fields Impermeable clay layer below

the soil. Construction of a water reservoir Natural obstruction to the flow of

ground water

Inhabiting activity of soil bacteria. Decrease in available capillary

water Fall in soil temperature Defective air circulation     Rise of salt  Delay in cultivation operations Growth of flora (unwanted plants

species) Adverse effects on community

health Less availability of oxygen   

Providing efficient surface Drainage. Reducing percolation(the slow passage

of a liquid through a filtering medium) from canals.

Restriction of unwanted irrigation. Adoption of sprinkler method for

irrigation Removing obstructions in natural

drainage.

REDUCING PERCOLATION FROM IRRIGATION CHANNELS

REDUCING PERCOLATION FROM WATER COURSES AND FIELDS

ENCOURAGING ECONOMICAL USE OF WATER

INCREASING OUTFLOW FROM THE GROUND WATER RESERVOIRREDUCING PERCOLATION FROM IRRIGATION CHANNELS

LINING OF CHANNELS

LOWERING OF FULL SUPPLY LEVEL OF IRRIGATION CHANNELS

PROVIDING INTERCEPTOR DRAINS AMONG CHANNELS CHANGING CROP PATTERN

CHANGING REVENUE POLICY

SALINITY If the concentration of harmful salts in the root zone of a plant increases to such on extent that plant growth is effected, this situation is called Salinity.Salinity.

Causes of Salinity The factors contributing towards the

problem of salinity are almost same as that of water logging.

Every agricultural soil has certain mineral salt in it like NaCl, Na2CO3, Na2 SO4 etc.

Controlled Irrigation. Providing adequate surface

drainage. Allowing lower intensity of

irrigation. Reducing surface evaporation. Not using alkaline water for

irrigation purpose.

The possible causes for salt-affected soils could be poor drainage, saline or sodic subsoil exposure due to erosion, parent soil material, use of high salt irrigation water, long-term use of some fertilizers, low rainfall or oil field activity.

The following techniques or events can help reclaim saline soils. Salt can be leached out of the root zone through good quality

irrigation water or by heavy rainfall. Create good surface and internal drainage. The use of tile

drains and open ditches in the fields can increase drainage and remove some of the salts.

Break the compacted layers that occur near or at the soil surface.

Add organic matter, such as rotted hay or feedlot manure, at 10-15 tons/acre to improve soil porosity.

There are some additional considerations in the reclamation of sodic and saline-sodic soils.

Reclamation of sodic soils is similar to saline soil in leaching the salts out of the root zone, except that gypsum should be added to remove the sodium. The amount of gypsum required depends on the soil texture and ESP.

Reclamation of these salt-affected soils is a very difficult thing and can take several years, so be patient.

Sandy soils in high rainfall regions can be reclaimed more easily than clay soils if rainfall is the only source of reclamation.