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Mixture of plants (Festulolium: Trifolium pretense L.) was grown in the pot experiment with different forms of nitrogen nutrition. The fertilizers (ammonium sulphate or calcium nitrate or ammonium nitrate) were applied conventionally or according to the CULTAN method (Controlled Uptake Long Term Ammonium Nutrition). The absolute growth rate (AGR) and contents of free asparagine and proline in the aboveground biomass were determined. Additional nitrogen increased the dry weight of biomass and AGR of the plants treated with sidedress application in comparison with plants treated with the CULTAN method. The results suggest increased levels of free proline in CULTAN-treated plants while those of asparagine did not increase. The significance of these observations to the loss of potential yield and the relationship between methods of application is considered.

The effect of nitrogen nutrition on phytosterol and amino acid content in aboveground biomass of maize (Zea mays l.) was investigated in a pot experiment. For cultivation of maize plants nitrogen dose (2 or 4 g n/pot) was applied in the form of ammonium nitrate (an) for control treatments or urea ammonium nitrate solution (Uan). Uan solution was applied according to the CUltan method (Controlled Uptake long term ammonium nutrition). The content of amino acids as important nitrogen-containing compounds in plant biomass was affected by nitrogen nutrition. an increase of glutamine and asparagine levels in maize aboveground biomass was observed after Uan solution application. The results of free β-sitosterol analyses by HPlC showed its 94% increasing concentration after Uan application in contrast to an treatments. our results confirmed that sterol interconversions are controlled by environmental conditions and they are involved in the regulation of membrane properties in response to changing growth conditions.

In this experiment we proved an effect of dolomite limestone on chemical immobilization in soil contaminated by trace metals, namely Cd, Pb, and Zn. Primary, we set up lysimeter pot experiment to measure soil leaching without vegetation. Willow clone (S. × smithiana Willd) was cultivated in the second lysimeter pot as a new approach to monitor Pb, Cd and Zn leaching, which was affected by soil liming (used in 1% rate). At the time of both harvests, aboveground biomass increased significantly at the amended variant. After the second harvest aboveground biomass production increased by 80% in comparison with the first one, Cd and Zn concentration in biomass decreased 2-fold and 3-fold, respectively. Dolomite limestone as a process of liming: (i) restricted metals leaching from the soil substrate; (ii) reduced metal uptake by willow; and (iii) increased biomass production of willow. Liming also alleviated the plant stress imposed by risk elements resulting in better plant growth and lower levels of stress markers (total nitrogen content and the main amino acid metabolism parameters in the willow leaves) yet through different mechanisms.

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