The chemical composition in the salt excretion of Tamarix ramosissima under conditions of different soil salinity level

Being grown on soils with different salinity degree, Tamarix ramosissima as the major representative of crinohalophytes reveals its ability to accumulate and removal the soluble salts. This is evidenced by a conjugated analysis to determine the chemical composition of soluble salts in ground waters, salt crusts, plant tissues and the salt excretion covering the Tamarix ramosissima sprigs. In these studies the soils were represented by hydromorphic solonchaks with salt crusts 5 and 0.1 cm thick and the content of toxic salts accounted for 32.4 and 57.6 respectively. The salinity was sulfate-sodium by nature. Based upon a comparative analysis of definite anions and cations in plant tissues and the salt excretion it seemed possible to notice that their content in salt secreted is higher by 3.2-7.7 times as compared to that in plant tissues. There is much in common in the content of cations and anions in the salt excretion of Tamarix ramosissima that can be presented in the following way: Na+ > Mg2+ > Ca2+ > K+ и Cl- > SO42-. It has been also established that the maximal removal of Na+ and Cl- in the salt excretion doesn’t connected with the amount of given ions in ground waters. One should be assumed that the content of Na+, Ca2+, Mg2+ и SO42- is associated with the concentration of these cations in salt crusts of the studied solonchaks. It is worthy of note that the Cl- exudation is not dependent on its content in the ground water and salt crust being comparable with Na+ exudation. Thus, Tamarix ramosissima grown under natural conditions reveals no direct dependence between the ions exudation by plants in the kind of salt excretion, the chemical composition and the amount of salts in soil (salt crust) and the ground water.