The present study was conducted on six Magnolia species in the period 2006-2008 in the Botanical Garden of the Maria Curie-Skłodowska University in Lublin. The soil and leaves from the locations of the following species of Magnolia were subjected to evaluation: cucumber tree (Magnolia acuminata L.), Kobushi magnolia (Magnolia kobus DC), purple lily magnolia (Magnolia liliiflora L.), Japanese willow-leaf magnolia (Magnolia salicifolia Siebold et Zucc. Maxim.), saucer magnolia (Magnolia x soulangiana Soul.-Bod.), and umbrella magnolia (Magnolia tripetala L.). The studied plants were planted during the period 1968-1989 on grey-brown podzolic soil derived from loess. The significantly lowest content of phosphorus, potassium and magnesium as well as the lowest pH were recorded in the soil from the location occupied by the purple lily magnolia (M. liliiflora). The other sites were characterized by an optimal range of pH, high soil phosphorus and magnesium availability as well as medium potassium availability. An optimal content of nitrogen and calcium was found in the leaves of the cucumber tree (M. acuminata), of phosphorus and magnesium in the leaves of the Kobushi magnolia (M. kobus), and of potassium in the leaves of the Japanese willow-leaf magnolia (M. salicifolia). A low content of nitrogen and calcium was shown in the leaves of the purple lily magnolia (M. liliiflora), of phosphorus in the leaves of the saucer magnolia (M. x soulangiana), and of potassium in the indicator parts of the cucumber tree (M. acuminata). The study found that among the studied species the cucumber tree (M. acuminata) could be a good biostabilizer of nitrogen, while the Kobushi magnolia (M. kobus) a good biostabilizer of phosphorus and magnesium. In spite of significant differences in soil nutrient availability and clear variations in macronutrient contents in the indicator parts of the investigated plants, no visual symptoms of nutrient deficit were found in the Magnolia species under study.
Growing strawberries under covers in substrates allows to eliminate the application of soil decontamination, which is costly and harmful for the environment. At the same time it guarantees obtaining a higher and better quality yield, as compared to the traditional ground cultivations. In the years 2005–2006 studies were conducted, aiming at determining the effect of three kinds of substratum (peat, peat mixed with composted pine bark in the proportion of 1:1, peat mixed with composted pine sawdust in the proportion of 1:1) and differentiated nitrogen dose (140 or 210 mg N·dm⁻³) upon yielding, chemical composition of leaves and fruit of strawberry (Fragaria × ananasa Duch.) of 'Honeoye' cultivar, grown in an unheated foil tunnel. The total and marketable yield quantity of strawberry fruit grown in peat and in peat with pine bark did not differ significantly. Lower total (407,1 g·plant⁻¹) and marketable fruit yield (264,6 g·plant⁻¹) was reported when plants were grown in peat mixed with sawdust. Plants grown in peat mixed with sawdust gave fruit with significantly lower unit weight compared to plants growing in the remaining substrates. The studies did not demonstrate a significant effect of differentiated nitrogen fertilization upon strawberry yielding. In the leaves of plants fertilized with nitrogen dose of 200 mg N·dm⁻³ significantly more nitrogen was found, as well as less calcium, compared to plants fertilized with a smaller dose of this component. In the fruits of strawberry fertilized with a larger nitrogen dose, significantly more nitrates (V), total nitrogen and potassium were reported and less dry matter, extract and calcium compared to fruit collected from plants fertilized with nitrogen dose of 140 mg N·dm⁻³.