Pseudogley is a typical type of acid soils predominating in both Serbia and the wider region. Acid soils are not suitable for the cultivation of agricultural crops due to the hampered uptake of most nutrients as induced by increased levels of hydrogen ions. In order to make pseudogley soil suitable for crop production, pH improvement measures should be employed. The objective of this study was to use liming to neutralise soil acidity and evaluate the effect of soil pH improvement measures on the Mo content in both root and leaf of the Dutch tomato ( Lycopericon esculentum Mill.) hybrid Belle planted under controlled conditions on pseudogley soil. Molybdenum was studied in this paper due to its role in plant nitrogen metabolism. Moreover, the determination of molybdenum presence in the root and leaf is a sure indicator of successful liming effects. Three liming treatments were employed (1, 3 and 4 t/ha CaCO 3 ). The liming operation used on pseudogley induced a statistically significant increase in molybdenum ion absorption into the root system of tomato. Independently from the aforementioned, the values for the root and leaf molybdenum content of tomato in each treatment were very low and insufficient for successful growth of this plant. In order to make pseudogley suitable for successful development of agricultural production, it is necessary to increase both soil pH and the content of available molybdenum in the soil. Key words: Liming, pseudogley, molybdenum, leaf, root, tomato.

Acid soils are not suitable for cultivation of agricultural crops as increased concentrations of hydrogen ions hinder the uptake of most nutrients. The adverse effects of increased soil acidity also include release of aluminium (Al) ions from the adsorption complex and hence, an increase in their concentration in the soil solution and plants. Aluminium ions block phosphorus and potassium uptake by the crop, thus leading to disturbance of plant growth and development, as well as to a substantial decline in crop yield and quality. This suggests that the use of such soils is not justified in terms of successful plant production. The objective of this study was to use liming to neutralise excess acidity of pseudogley soil under oat crop and evaluate the effect of soil pH improvement measures on the aluminium content of both the leaf and root of oat ( Avena sativa L.) cv. Mediteran. Three liming treatments were employed [1.0, 3.0 and 4.0 t ha -1 calcium carbonate (CaCO 3 )]. The treatments with 3.0 and 4.0 t ha -1 CaCO 3 induced no Al presence in oat plants, suggesting that liming in these treatments was successful in terms of aluminium content. Key words: Aluminium, leaf, oat, pseudogley, root.