Investigation of the dependence of the intake and distribution of tritium on the vegetative organs of agricultural plants during hydroponic cultivation

Abstract As part of the study, the essential importance of the aerial mechanism of tritium in-take into plants was revealed, and a quantitative assessment of the parameters characterizing this transfer mechanism was given. It is shown that for such crops as cucumber, tomato, corn, the proportion of water supplied to the plant by the aerial mechanism is on average about 30% of the total water absorbed by the plant. It has been revealed that the ability of plants to absorb water from the air increases during the growing season. A quantitative assessment of the parameter characterizing the downward (from the leaves to the roots) flow of water - the newly introduced coefficient K aps - has been carried out. The K aps coefficient actually shows the amount of water transferred by the plant by the downward flow in milliliters per kilogram of green mass per day. The average value of the K aps was for the crop: cucumber - 240, tomato - 320, corn - 300 ml/(kg * day). The presence of two significant routes of tritium intake at different concentrations in its carrier media (soil solution at the root route of entry, air vapors at the aerial route) leads to an uneven distribution of tritium concentration across organs and parts of plants. For all plants and at all stages of vegetation, there is an excess of free water tritium con-centration in leaves over concentrations in stems: 1.4 times for cucumber culture, 3.6 for tomato, 2.4 for corn. The difference in concentrations of TFWT in leaves and roots is even more pronounced: 7.6 for cucumber culture, 6.7 for tomato, 3.6 for corn. The presence of significant concentrations of tritium of free water in plants, and especially in the roots, that is, in its part, which usually remains in the soil, as well as the revealed transition from plants to soil solution under conditions of its aerial formation shows the importance of a special mechanism of soil contamination with tritium along the path “water vapor of air - the free water of plants - the soil.” The presence of this mechanism can lead to soil contamination with tritium in the absence of tritium-contaminated groundwater and surface waters, which, as a rule, are considered as the main source of pollution by it.