What are saline and sodic soils?
Saline soils have excessive amounts of soluble salt, while sodic soils have high amounts of exchangeable sodium in the soil itself.
What causes soil salinity in Pakistan?
Improper irrigation practices and lack of drainage have generally led to accumulation of salts in the soil in concentrations, which are harmful to the crops. There is a major imbalance in the amount of salt entering and leaving the soil in Pakistan.
Where are saline soils found?
The Saline soil is found in Uttar Pradesh. It is also found in Punjab and in some parts of Gujarat, Bihar, Haryana, Maharashtra. Saline soil exists in arid and semiarid regions and in regions of poor natural drainage. Its soils have poor physical properties due to high acidity and low pH.
How much of Pakistan is affected by salinity?
In Pakistan, about 14% of irrigated lands have deteriorated with salinity, while 64% yield losses are reported due to salinity.
What is a sodic soil?
For the purpose of definition, sodic soils are those which have an exchangeable sodium percentage (ESP) of more than 15. The soil a few centimetres below the surface may be saturated with water while at the same time the surface is dry and hard.
What is difference between sodic and alkaline soil?
The key difference between saline and alkaline soils is that saline soils have a pH less than 8.5 and an exchangeable sodium percentage less than 15, while alkaline soils have a pH greater than 8.5 and an exchangeable sodium percentage higher than 15. Acidic soil and basic soil are two major types among them.
How can control salinity in Pakistan?
If salinity and waterlogging issues continue to rise, Pakistan’s cultivated land will be reduced. Sindh SCARP wells evaluation: East Khaipur drainage in Sindh was also placed to combat problems with waterlogging and salinity.
Which area of Pakistan is suffering due to water salinity?
Soil salinity is a serious problem of agriculture in Pakistan. Salt-affected soils alone occur on more than six million hectares and more than 70% of the tube-wells in saline areas are pumping out brackish water. The problem is more severe in Sindh and Southern Punjab than other parts of the country.
Which crops are grown in saline soil?
7.3 Crops and saline soils
| Highly tolerant | Moderately tolerant | Sensitive |
|---|---|---|
| Barley | Tomato | Peas |
| Sugarbeet | Oats | Beans |
| Cotton | Alfalfa | Sugarcane |
| Asparagus | Rice | Pear |
What is the most salt tolerant crop?
“The most salt-tolerant crops are barley, camelina, rye, safflower, sunflower, and sugar beets,” says Aberle. “We’ve replaced a lot of these crops with the least-tolerant crops, which are dry beans, soybeans, corn, and field peas.”
How does saline sodic soil reclamation take place?
Reclamation of saline–sodic soils requires the removal of sodium from the soil exchange sites by divalent cations (preferably Ca2+) to promote soil flocculation. The most common amendment source can be calcium, which provides soluble calcium within the soil.
How sodic soils are formed?
Sodic soils occur when soil is saturated with sodium salts and the exchange sites contain exchangeable sodium that usually persists even when the soluble salts are removed. As these minerals and parent rock are weathered via surface and ground waters, the salts solubilize and start to affect the soil.
What is soil salinity in Pakistan?
Soil salinity is one of the major issues in the agriculture sector of Pakistan. The salt-affected soil is categorized into three types (saline, sodic and saline-sodic soils). … Content may be subject to copyright. Content may be subject to copyright. Agriculture sector is performing a vital role in the economy of Pakistan (GDP 21 %).
What is saline-sodic soil?
Saline-Sodic soil contains soluble salts as well as exchangeable sodium. Its EC > 4 dS/m (saturated paste), Ph > 8.5, ESP > 15 and SAR < 13.2. At present, the total salt affected soil on the surface of the earth is about 954 million hectares. Such types of salt affected soils are distributed throughout the world.
How can we solve the problem of saline soil?
To address the saline soil problem, some of the measures tested include leaching of salts by excess irrigation, use of chemicals (such as gypsum and acids), and addition of organic matter and biological measures (such as salt-tolerant plants, grasses, and shrubs).
What is needed to manage salinity in the Indus basin?
A more concerted effort that includes a greater focus on saline agriculture, capacity building of farmers, and promotion of local interventions to improve self-reliance is necessary for the management of salinity in the Indus Basin.