Higher plants can withstand high salinity by either salt exclusion or salt inclusion. Salt excluders possess the ability to exclude salts from the entire plant or from certain organs. In such cases membrane selectivity favors the uptake of K+ over Na+, thus excluder crops are characterized by having low Na+ and Cl- content. Salt accumulators, on the other hand, are able to cope with the uptake of high salt concentrations through one of two strategies. The first, a common characteristic of halophytes, is through tolerating high levels of intercellular salts by resistant cell membranes. In such cases, high tissue Na+ to K+ ratio is evident. The second strategy is through removal of excess salt entering the plant, where root can take up salt ions but avoid their injurious effect. To improve crop growth and production in the salt-affected soils, the excess salts must be removed from the root zone. Methods commonly used in reclamation such soils are scraping, flushing and leaching. These methods were found to be very expensive. Recently, attention was given to use other new technologies of combating salinity, among them using halophytes. Halophytes are plants that can tolerate high salinity levels and remove the accumulated salts from the surface layer of the soil as well. Halophytes are plants from over 80 families which evolution have developed ways to deal with large amount of salts in the water they uptake. Some halophytes have specialized leaf cells called salt glands that excrete salt. Others have salt hairs present on the stem that excretes salt. Some plants have stomatal guard cells that are controlled by the sodium ion. These plants control their transpiration in accordance to the amount of salt present in the environment. The use of such plants to reclaim salty-affected soils has become cheaper and more practical than chemical reclamation.
Very interesting. Salt tolerance in plants is a complicated mechanism included morphological, physiological and biochemical processes ) The alteration in cell phenotypes to survive and grow in the presence of high levels of NaCl is correlated with biochemical and physiological changes which in turn involve in gene expression alteration . Many previous researchers studied the variation in SDS-PAGE protein patterns of plants in response to salinity. Moreover, the response to salinity stress through protein changes might be a reason for salinity tolerance in this condition .. This variation includes the over-expression; new expression and suppression of some proteins. In Wheat, adaptation to salinity depends on the expression of salt-induced proteins. Some interesting PDFs enclosed...
Plants obtain most of their water from the soil, and when that water increases in salinity it takes the plant more energy to draw it up through its roots and the plant can Sometimes dehydrate even when there is water available, because it cannot keep up with the effort required to replenish its water supply.Salt build-up within the plant itself also has effect. This shows more so in older leaves which have had longer exposure to salt excess.Salinity is becoming an increasing problem along waterways, on irrigated land, deserts and other areas, worldwide. Lack of flowing fresh water to flush our rivers, salts and other minerals etc in our water supply, along with other problems, all contribute to this. The plants that grow naturally, and those we plant, can be affected by changes to the natural salinity of their environment, usually in a detrimental way, especially to more sensitive plants.
This informative video goes into the causes of ground salinity and looks at some of the solutions. Well worth watching to gain a better understanding of what is actually going on.
One of the best ways to deal with a soil salinity problem, especially if you are just starting out, or redesigning your garden, is to plant salt tolerant plants. Not only are they equipped to deal with the salt, but often actually flourish in it, and being ideally suited to the conditions, are often lower maintenance than those that are not. They are also often drought tolerant.
There are many salt tolerant plants depending on just how much salinity you have to deal with, but to get an idea of what might grow well in your area, go for a wander and see what is growing happily and abundantly. Also, look at what the council has planted in the way of street trees and on roundabouts and median strips... assuming they are growing well. If you live near the beach, have a look at what is growing along the foreshore. Simple observation can often give you the best information.
Regards,
Prem Baboo
To Dr. Singh, Dr. Srivastava, Dr. Baboo,
I am from a different field. A few days ago I asked a question, but not received any satisfactory answer.
During my field study in saline soil belt of Purba Medinipur district of West Bengal, India, some people reported that cultivation of Acacia nilotica tree surrounding paddy field helps to reduce salinity of the agricultural land by decomposed fruits and leaves of the plant. They cultivate the plant inside their paddy fields.
Is it true? How it can happen?
Please answer.
DR Pattanayak, Acacia nilotica also known as babul in India is infact having some properties which can ameliorate soil salinity.Infact i am attaching one pdf on this tree and a latest book which can help you in understanding the biormediation properties of this tree plant.Of course CSSRI (Central soil salinity research institute) has also done some good work on it and you can find details on their site or by contacting the scientists working their.
The details of book are:
Bioremediation of Salt Affected Soils: An Indian Perspective-Springer publication
edited by Sanjay Arora, Atul K. Singh, Y.P. Singh
