B. Rutkowska

Frequently asked questions about in vivo chlorophyll fluorescence: practical issues

The aim of this educational review is to provide practical information on the hardware, methodology, and the hands on application of chlorophyll (Chl) a fluorescence technology. We present the paper in a question and answer format like frequently asked questions. Although nearly all information on the application of Chl a fluorescence can be found in the literature, it is not always easily accessible. This paper is primarily aimed at scientists who have some experience with the application of Chl a fluorescence but are still in the process of discovering what it all means and how it can be used. Topics discussed are (among other things) the kind of information that can be obtained using different fluorescence techniques, the interpretation of Chl a fluorescence signals, specific applications of these techniques, and practical advice on different subjects, such as on the length of dark adaptation before measurement of the Chl a fluorescence transient. The paper also provides the physiological background for some of the applied procedures. It also serves as a source of reference for experienced scientists.

Availability of Microelements as Affected by Soil Reaction and Fertilization in Long-Term Field Experiments

Results presented in this paper come from two long-term fertilization experiments carried out in Skierniewice (since 1923) and _ yczyn (since 1960). The top layer of soil in Skierniewice contains a little more clay and silt (17%) than at _ yczyn (14%), but the climatic conditions are alike - the mean for many years shows the precipitation of 520mm and temperature 7,9°C. Soil samples for the determination of microelements were collected in the years 1999 and 2000 from the control plots (Ca) and from combinations corresponding to 3 fertilization systems: mineral (CaNPK), organic (Ca + FYM) and mixed organic-mineral (CaNPK + FYM). The contents of B, Cu, Zn, Mn were determined in 4 extract solutions: 0,01mol CaCl2, EDTA, 1mol HCl and HF (total contents). The paper presents average results for the last two years. The following amounts of microelements (%) in relation to the total contents in particular extract solutions were obtained: CaCl 2 m Cu 0,4< Zn 2,2< Mn 3,5 < B 5,0; EDTA - B 2,4 < Mn 5,7 < Zn 9,0 < Cu 13,9; HCl - B 7,8 < Cu 37,3 < Zn 37,6< Mn 72,5. The soil contents of readily soluble forms of Mn were significantly higher in non-limed than in limed soil, while the amounts of B, Cu and Zn were higher in limed soils as some amounts of Cu and Zn were present in lime fertilizers. In the system of mineral fertilization, some amounts of boron and zinc were introduced to the soil together with fertilizers, however, they were insufficient in view of nutritional requirements. On the other hand, in the organic-mineral system the amounts of introduced boron were adequate, copper and zinc twice higher and manganese four times higher. The use of mineral fertilization alone for 26 years, leads to soil depletion of zinc and copper and the use of manure alone enriches soil in those components.

Exchangeable silicon content of soil in a long-term fertilization experiment.

Based on a long-term fertilization experiment on a light soil, a study was conducted on the impact of varied fertilization on the levels of silicon forms available in the soil. It was shown that the exchangeable silicon content in the tested soil was very low, which can have a limiting effect on crop yields. Soil pH is a factor that significantly affects the exchangeable silicon content of the soil. Therefore, under the conditions of acidic soils, liming is a treatment that increases the level of silicon forms available to plants in the soil.

The attempt to utilize chemical composition of soil solution in fertilization diagnostics

Soil solution is a significant link in the process of plant nutrition. Analysis of the soil solution as a background of fertilization diagnostics may be very promising. Concentration of ions, being the nutrients in the soil solution is relatively low. Therefore, the questions arises: to what degree — in quantity aspect — the components of the soil solution cover the nutritional requirements of plants. The degree of quantitative coverage of nutritional requirements of the selected plants by ions (P, K, Ca, Mg, B, Cu, Mn, Mo, Zn), contained in the soil solution of arable layer of cultivated soils from Poland, was evaluated. To illustrate this relationship the the synthetic index, which has been called “solution recovery coefficient” (SRC), was calculated.

Accumulation of selected heavy metals in soils and common dandelion (Taraxacum officinale) near a road with high traffic intensity

Abstract The aim of the study was to determine the levels of selected trace elements in soils and in the common dandelion depending on the distance from a traffic route. The study was conducted in Warsaw near one of the main roads in the suburb of Ursynów. Samples for testing were taken from the 0–25 cm layer at sites located directly alongside the roadway and at a distance of 30, 60 and 300 m from its edge. The amounts of Pb, Ni, Cu, Zn and Cd in the soils were determined by the AAS method, after extraction in HCl at a concentration of 1 mol·dm−3, and in the aboveground parts and roots of dandelion plants after wet mineralization in a mixture of HNO3 and HClO4 by the AAS method. On the basis of the results obtained, it was shown that the concentrations of the tested metals, both in the soils and in the biomass of the test plant, were highest directly at the edge of the roadway and decreased significantly with the distance away from the road. This correlation indicates a significant impact of road transport on heavy metal levels in the environment bordering a traffic route. It was also shown that dandelion plants accumulate higher amounts of heavy metals in the aboveground parts than in the roots, and the heavy metal contents in the dandelion biomass were found to be significantly positively correlated with the amounts of these elements in the soils.

Influence of sulphur and multi-component fertilizer application on the content of Cu, Zn and Mn in different types of soil under maize

The aim of the study was to determine the influence of the soil type and differential sulphur rates used with or without Basfoliar 36 Extra on the soil pH as well as the amount of available forms of copper, zinc and manganese based on the micro plots field experiment. Moreover, the relationship between the studied microelements was examined. The experiment was performed in two-factor design; the first-order factor was the soil type (Typic Hapludolls, Typic Hapludalfs, Typic Haplorthods, Typic Endoaquolls), while the second-order factor - fertilization with sulphur and compound fertilizer - Basfoliar 36 Extra. The plant tested was Rota cultivar maize. The use of sulphur and sulphur combined with Basfoliar 36 Extra changed the classification of the soils in terms of their pH. In the soils under study, as a result of the 10-years application of sulphur and/or foliar fertiliser with NPK fertilization as well as growing maize in monoculture showing a high uptake of macro- and micro-nutrients, there was reported a clear decrease in the content of zinc, copper and manganese, as compared with the initial content. With that in mind, one shall assume that growing maize in a 10-year monoculture is connected with an intensive use of soils, which can result in a clear deficit of the elements studied in soil.

The impact of long-term application of inorganic nitrogen fertilizers and manure on changes of selected properties of organic matter in sandy loam soil

The aim of the research was to assess the effect of long-term application of different doses of nitrogen fertilizers with or without manure to changes in the total organic carbon content, total nitrogen content, evaluation of dissolved organic carbon content and the value of absorbance coefficient (A4/6) in sandy loam soil. The base of research was the long-term field experiment, established in 1979 at the Wierzchucinek Experimental Station close to Bydgoszcz city - Poland. The experiment was carried out in the three-course crop rotation, potato, rye, rye in randomized split-plot design. The experimental treatments were four levels of N fertilizers in 0, 47, 93, and 140 kg∙ha-1∙yr-1 (N0, N1, N2, N3) as a 1st factor of experiment, and the same doses of N fertilizers with farmyard manure application (30 t∙ha-1) as a 2nd factor. After 36 years of experiment the content of total organic carbon was 26% lower and the content of total nitrogen 13% higher compared to the values determined before the experiment foundation (1979). The consequence of changes in the content of organic carbon and total nitrogen, are changes in the ratio of organic carbon content and total nitrogen content. It was noticed that the use of manure and different nitrogen doses resulted in a decrease of organic carbon content and total nitrogen content value. After application of different nitrogen doses, organic carbon content ranged from 122.4 to 152.2 mg∙kg-1. The same nitrogen doses applied simultaneously with farmyard manure increased the organic carbon content, which ranged from 133.5 to 166.7 mg∙kg-1. The changes of the organic carbon content did not effect on percentage of this fraction in the total organic carbon. Percentage of organic carbon content in total organic carbon content was on averaged 1.6%. After the application of different nitrogen doses, humic acids of analyzed soils were characterized by lower average value of A4/6 (5.4). However, the application of nitrogen doses with manure brought a higher - 6.3 - A4/6 value. Farmyard manure application caused the formation of humic acids of lower molecular weight and a low humification degree.

Ion Equilibrium in the Soil Solution in Long-term Fertilization Experiment on Sandy Soil

In the conditions of long-term experiment carried out in the experimental field of Warsaw Agricultural University - SGGW at _ yczyn, ion concentration in the soil solution were examined as well as the relationships shaped between ions in the soil solution due to long-term diversified mineral and organic fertilization. Soil solution was obtained by the vacuum method and the concentration of particular ions in the soil solution was determined by the ICP method. Mineral and organic fertilization and liming significantly affected chemical composition of the soil solution and the relationships between particular ions in the soil solution. The lowest concentration of ions in the soil solution was observed in the control plots (not fertilized). Mineral and organic fertilization as well as liming caused the increase of ion concentration in the soil solution. In the plots with mineral fertilization alone K + and NH + 4 ions predominated in the cation structure in the soil solution. In the case of liming the share of Ca 2+ ions increased. Independently from the system of fertilization used, CI m and HCO m 3 ions predominated in the anion structure. The application of organic fertilization affected to the highest degree the concentration of aluminium ion in the soil solution significantly limiting the share of this ion in the cation structure.