Loss of water by plants. Salinity

you are: Loss of water by plants

In all irrigated areas of the world the soil becomes more salty. High concentration NaCl and other salts in irrigating water damage plants as osmotic effects brake water absorption, and sodium ingibiruet enzymes in cytoplasm. Therefore at accumulation of salt of a plant become sickly and eventually cease to grow.

As in the conditions of an arid climate actually all irrigation water evaporates, salinity of soil increases nesmotrja even that irrigating water usually contains only insignificant concentration of salts. Salts remain in soil, and their quantity slowly increases until concentration will not start to damage a plant. During this moment it is necessary or to stop agricultural use of soil, or to wash out its superfluous quantity of water for salt removal. However the considerable quantities of water necessary for washing, are often inaccessible in the zones demanding an irrigation.

To bypass this problem, it is possible to use two ways. The first way - the drop irrigation providing with enough of water separate plants, but not humidifying soil between them. It is carried out by a lining of a pipe along each number of plants. Apertures in a pipe are located so that each plant received water necessary for it, and on having watered free sites water was not spent. Irrigating water even if in it the salt small amount contains, tends to wash away salts in the depth korneobitaemogo a layer, in the most this layer water remains fresh so accumulation of salt harms to plants less. A drop irrigation use for fruit-trees or such plants as salad, but it is inapplicable for cultures of continuous sowing, for example wheat. it is clear that this method can postpone only a day of reckoning, if a climate absolutely dry. However in some droughty areas there is also a rainy season that leads to soil washing; in such cases the described method not only keeps water during a dry season, but even allows to use moderately salty water which would be harmful at an irrigation by overhead irrigation or flooding.

Other way - selection on soleustojchivost. Soleustojchivye plants, galofity, meet in the nature. They cope with a problem of salinity by absorption of significant amounts of salt therefore the water potential of their cages allows them to soak up water even from the salted soil. Thus salt collects in cellular vakuoljah so the high maintenance of sodium does not influence cytoplasmatic enzymes. experiences have shown that special lines of some plants which usually are not considered as galofity, can possess considerable stability to zasoleniju. For example, soleustojchivaja the line of barley deduced by Emanuelem Epstein (the Californian university in Devise), yields a harvest in the conditions of such salinity at which usual barley perishes. The further selection of this line can give a grade for cultivation on the salted soils.