<% if not session("Auth") then response.redirect("suf.php") end if %> WATER AND SALINITY

WATER AND SALINITY

 

July 02 - 08 , 2001

Q. What is the permissible range for drinking water?
A
. The permissible range for drinking water as recommended by WHO is 500 ppm or 500 mg salts/kg water.

Q. What are the three classes of underground water?
A
. The three classes of underground water are usable, marginal, and hazardous.

Q. What is the quality range of usable water?
A
. Whose electrical conductivity is less than 1.5 dS/cm (or 960 ppm) lmg/kg= lppm) Such water can be used directly for agriculture.

Q. What is the quality range of marginal water?
A
. The quality range of marginal water is with EC of 1.5 to 3 dS/cm or 960 to 1920 ppm .Such water cannot be used directly for agriculture, because of higher concentration of salts and have to diluted with sweet waters.

Q. What is the range of hazardous water?
A
. The range of hazardous water is 3 dS/cm and above. This quality of water is totally unsuitable for agriculture.

Q. What in the EC of Indus water?
A
. The EC of Indus water is about 1.0 dS/cm or nearly 700 ppm.

Q. What is the quality of a non-saline or a good soil?
A
. The soil whose EC is less than 4 dS/c~m (2560 ppm).All sorts of crop can be grown.

Q. What is a saline soil?
A
. Saline soil having EC greater than 4 dS/cm, pH below 8.5 and ESP( exchangeable sodium percentage) less than 15, contain chlorides and sulphates of sodium, calcium and magnesium. This quality of water is totally unsuitable for agriculture.

Q. What are the marginal soils?
A
. Soils with EC about 8- 15 dS/cm(or 5120-9600 ppm) are marginal soils—Crops like sorghum, barley, canola, mustard, spinach, sugar beet, guar, dhancha, Berseem, lucerne, sweet clover, fig, grape etc. can be grown.

Q. What are the hazardous soils?
A
. Soils having EC 15-20 dS/cm or (9600-12800 ppm) are marginal soils—Crops like Date palm, coconut, kallar grass orchard grass, Bermuda grass and Sudan grass, Wood species like Jojoba, guava, mesquite, Acacias. Atriplex, Life plant, Aloe veera, Bottle palm, China rose, Banana, Senna, Cactus etc. Can be grown . Some of them consume enough quantities of water to affect the ground water level.

Q. What is the total land area of Pakistan ?
A
. The total land area of Pakistan is 79.6 mha.

Q. What is the total land area of Punjab?
A
. The total land area of Punjab is 20.60 mha.

Q. What is the cropped area of Punjab.
A
. The cropped area of Punjab is 11.04 mha (56% of total land of the country).

Q. What is the total land area of Sindh?
A
. The total land area of Sindh is 14.10 mha. of which 5.45 mha. is cropped (27.50%) of the total land area of the country.

Q. What is the total land area of NWFP?
A
. The total land of NWFP is 10.20 mha. of which 1.93 mha is cropped (9.7% of the country)

Q. What is the total land area of Balochistan?
A
. The total land area of Balochistan is 34,70 mha, of which only 1.40 mha (7.06%) is cropped.

Q. What is the strength of cropped area in the country?
A
. The strength of cropped area is about 20 mha. Or 25 .5% of the total land area is under cultivation

Q. How much cropped area is under irrigation in the country?
A
. About 15.2 mha or about 75 % land is under irrigation.

Q. How much area is under rain-fed?
A
. About 4.25 mha. or 19% of the land is under rain-fed. About 4% lands irrigated by tube-well

Q. How much area of Pakistan is under salt-affected?
A
. About 6.3x103 mha. of land is under salt-affected.

Q. How much area of Punjab is under salt-affected?
A
. About 3.28 mha. area of Punjab is salt-affected.

Q. How much area of Sindh is salt-affected?
A
. About 3.06 mha. of land is under salt-affected

Q. How much land of NWFP is salt-affected ?
A
. About 0.61 mha. of land in NWFP is salt-affected.

Q. How much land of Balochistan is salt-affected?
A
. About 0.1 mha. of land in Balochistan is salt-affected.

Q. How we can improve salt-affected land?
A
. We can improve salt-affected land by- scrapping of salt layer, ii) by land Raveling. ii) deep ploughing, iv) sub-soiling, v) sanding, vi) flushing the salt-affected land with good quality water and drainage, vii) application of higher seed rate for higher plant population. By Manuring through legumes, application of farm yard manure, gypsum and sulphuric acid.

Q. What is the range of salt-affected soils of the world?
A
. The ranges of total salt-affected soils of the world are about 925 million hectares.

Q. What is the range of salt -affected soil in Asia.?
A
. The range of salt-affected land in Asia is 316.50 mha.

Q. What is the range of salt-affected land in Europe?
A
. The salt-affected is about 50.80 mha.

Q. What is the range of salt -affected land in Africa?
A
. At the range of salt-affected land in Africa is about 80.54 mha.

Q. What is the range of salt-affected land in Australia?
A
. The range of salt-affected land is Australia is 357.3 mha.

Q. What is the range of salt-affected land in North America?
A
. The range of salt affected land in North America is about 17.72 mha.

Q. What is the range of salt-affected land in South America?
A
. The range of salt-affected land in South America is 129.2 mha.

Q. What is the range of salt-affected land in India?
A
. The range of salt-affected land in India is about 7 mha. (The total land of India is more than 4 times greater than the area of Pakistan)

Q. What is the range of salt-affected land in Pakistan?
A
. The range of salt -affected land of the country is more 6.0 mha, of which 4.2 mha is located in Indus Basin.

Q. How much area in Pakistan is affected by waterlogging and salinity?
A
. The area affected by waterloggng (water table within 5 feet) is 2.339 mha, while area affected by soil salinity is about 2.55 mha.

— Dr. S. M. Alam;