Micronutrients are as important as macronutrients for crops. Each micronutrient has its own function in plant growth. Zinc is important for membrane integrity and phytochrome activities. Copper is an essential micronutrient required for the growth of wheat. Manganese is required for enzyme activation, in electron transport, and in disease resis...tance. The pot experiment was set up in greenhouse on calcareous chernozem soil Debrecen-Látókép with a spring wheat. In certain development stages (according to BBCH growth scale of wheat), at the beginning of stem elongation (29–30), at the heading (51–59), at the flowering (61–69) stage three average plants were removed from all pots for analysis. Fresh and dry weight of the plant samples were measured. Plant leaves after drying were digested by HNO3-H2O2 methods and manganese, zinc and copper contents of plant were quantified by atomic absorption spectrophotometry. At the flowering stage, when the nutrient uptake of plants is the most intensive, the weight of wheat ranged between 0.94–1.57 g plant-1. In this development stage, the NS2 treatment produced the highest weight of wheat, and compared to this the NS3 treatment decreased that value already. The results show unfavourable effect of NS3 treatment. On the basis of microelement content of wheat and the weight of a plant, nutrient uptake by plant were calculated. At the beginning of growth the starter treatment had positive effect on Cu-uptake compared to the NS1 treatment, where the same dose of fertilizer was stirred into the soil. Wheat is very sensitive to copper deficiency, so copper dissolved by starter treatment could be favourable to the early development of wheat. At flowering stage the Zn-uptake of wheat became the highest and it was between 133.7–234.6 mg plant-1. The Mn-uptake of wheat plant was higher than the Cu- and Zn-uptake of wheat.
This phenomenon can be explained by the fact that the untreated soil had higher Mn-content, than Cu- and Zn-content. To summarize the results, it can be stated, that the copper uptake of wheat was more affected by the different treatments in the stage of stem elongation, while Mn- and Zn-uptake of wheat were influenced primarily in the stage of heading and flowering.
The aim of this work was to evaluate the changes of different sulphur forms (soluble, adsorbed) in chernozem soil in a long-term field experiment supplied with increasing doses of NPK fertilizers for a long time. In addition, other objective of this study included the examination of the applicability of recommended extractants of the different...sulphate fraction in Hungarian soils. A long-term field experiment was established at the Research Station of Látókép of the University of Debrecen in 1984. In addition to control, two levels of NPK fertilizer doses have been used with irrigated and non-irrigated variants. Winter wheat and corn were cropped in a crop rotation on plots. Soil samples were collected in three different development stages of winter wheat, at the stage of stem elongation (April), flowering (May) and ripening (June of 2018) from the topsoil (0–20 cm) of experiment plots. Water-soluble inorganic sulphate was extracted with 0.01M CaCl2 solutions. The soluble plus adsorbed sulphate was extracted with 0.016M KH2PO4 solution. Sulphate was measured by turbidimetric method. 0.01M CaCl2-SO42— ranged between 0.293–1.896 mg kg-1 and the 0.016 M KH2PO4-SO42- varied between 5.087–10.261 mg kg-1. The values of KH2PO4 SO42- was higher than that of CaCl2-SO42-, because KH2PO4 extracted the adsorbed and soluble fractions of sulphate, while CaCl2 extracted the soluble sulphate fraction. The amount of absorbed sulphate was calculated by the differences of KH2PO4- SO4 and CaCl2-SO4. The KH2PO4 characterizes mainly the adsorbed sulphate fraction much more than the water-soluble fraction. KCl is the most widely used extractant for the determination of plant available sulphate content of soil in Hungary; therefore, KCl-SO42- fraction also was determined. The KCl-SO42- ranged between 0.328–2.152 mg kg-1. The CaCl2-SO42- and KCl-SO42- fractions were compared and based on Pearson's linear correlation, moderate correlation was established (r=0.511) between them. In all three extractant (0.01M CaCl2, 1M KCl, 0.016 M KH2PO4) higher sulphate fractions were measured in the fertilized plots where superphosphate had been supplied for ages until 2010. The arylsulphatase activity of soil also was determined and ranged between 9.284 and 26.860 µg p-nitrophenol g-1 h-1. The lowest value was observed in the treatment with highest NPK2 dose, both in irrigated and non-irrigated areas.
The objective of this study was to evaluate the impact of long term NPK fertilization (considering that S containing superphosphate was supplied for 26 years of experiment, but since 9 years S has not used any longer) on sulphur- and nitrogen content and N/S ratio of winter wheat. The second objective of this work was to determine the chang...es of the amount of the different nitrogen and sulphur fraction in chernozem soil in a long term fertilization experiment. The third aim of the work was to determine if a relationship could be established between the studied parameters. Based on our results, it can be stated that the sulphur containing superphosphate supplied in the period of 1984-2010 has no longer significant effect on total sulphur content of plant in 2018. The NPK fertilization treatments had positive effect on total nitrogen content of winter wheat. In general, increasing NPK doses resulted in significantly higher nitrogen. The effect of irrigation applied in previous years has no statistically significant effect on the sulphur and nitrogen content of wheat. The wheat grain produced in our experiment, especially in fertilized treatments showed S deficiency. Analysing the changes of CaCl2 soluble nitrate-N and total N of the soil, it can be stated that the effect of increasing fertilizer doses clearly appears in these parameters, because the treatment with increasing fertilizer doses resulted higher CaCl2 soluble N forms compared to the control treatment in soil. These values increased until flowering stage of wheat and after that a slightly decrease was observed as a result of higher N uptake of plant. In overall, it can be stated, that the effect of superphosphate on measured sulphur fraction is prevailed. With increasing fertilizer doses higher sulphate content was detected in soil, but the sulphate content measured in different soil extractant is not enough for the wheat in this experiment area. Studying the correlation between the measured parameters of plant and soil, it can be concluded, that the relationships between nitrogen in the plant and in the soil is stable, and did not change during the growing season. The correlation between plant S and soil S varied in the measured periods and the r value was low in most cases. At the stage of flowering the highest r value was found between KCl-SO4 and plant S. In the stage of ripening the strongest correlation was detected between KH2PO4-SO4 and grain S content.