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Simple balance of Cd input by different treatments and removal by agricultural crops was investigated in an ongoing precise long-term field experiment with application of sewage sludge (SS), farmyard manure (FYM), and mineral fertilizers (NPK). Potatoes, wheat and barley were grown in a rotation at 4 experimental sites of the Czech Republic with the aim to assess the risk of Cd accumulation in soil and plants under different soil and climate conditions. The results showed significant differences in Cd content of the input materials used, and in Cd inputs to soils under different fertilization managements. Three applications of sewage sludge during 1996-2005 resulted in total addition of 110 g Cd/ha into soil, which was by one order of magnitude higher than Cd addition in FYM or NPK treatments. From the total amount of sludge-borne Cd, only small portion was removed by harvests of crops (approximately 3.5%). Soil conditions significantly affected Cd input-removal balance. The highest Cd removals were obtained on soils with the lowest pH. The highest Cd removal was achieved by potato tubers followed by wheat and barley plants. The results showed that the risk of Cd accumulation in soils is high, especially with repeated sludge applications.

Net N mineralization rate (NMR), net N consumption rate (NCR), microbial biomass carbon (MBC) and nitrogen (MBN), potentially mineralizable N (PMN) and mineral N (N-NH⁺₄ and N-NO^-₃) were measured in paddy soil at five growth stages of rice to determine the effect of long-term fertilization in subtropical China. The studied long-term treatments included CK (no fertilization), N, NP, NPK and NPK + OM (NPK plus organic manure). The NPK + OM treatment gave the highest values of the measured variables among all treatments. There was no significant difference in other treatments except for mineral N and PMN at early growth stages. All these variables were generally highest at transplanting stage as two thirds of fertilization was applied as basal fertilizers and the rice uptake was low. Then they decreased or leveled off with the rice growth stages except for MN in all treatments. Stepwise regression revealed that NMR was significantly correlated with MBC and N-NH⁺₄ (R² = 0.954, P < 0.01) at all rice growth stages. So, mineral plus manure fertilizer application and more mineral fertilizer as topdressing were recommended in subtropical paddy soil.

Soils were sampled from the plots with four variants of fertilisation: Nil - without fertilisation, NPK - mineral fertilisation, FYM - farmyard manure, FYM + NPK - farmyard manure with mineral fertilisation, and two variants of crop rotation: field IV - classical 9-year crop rotation, field B - 2-year rotation of alternative growing. Determination of urease, CFU of Azotobacter spp. and potential nitrogenase activity was conducted during the period 1999-2004. The urease activity was positively affected by manure fertilisation (FYM) and by the combination of FYM + NPK. The statistically significantly highest counts of Azotobacter spp. and the highest nitrogenase activity were determined on field B in variants FYM and FYM + NPK. The results show that there was a higher amount of accessible nitrogen present on field IV than on field B. This might explain the lower counts of Azotobacter spp. and therefore the lower nitrogenase activity. According to our results, activity of urease, CFU of Azotobacter spp. and potential nitrogenase activity are very closely connected with N inputs.

The objective of this study was to evaluate the influence of organic (cattle manure) and inorganic fertilizers [composite NPK (15:15:15)] and natural zeolites on soil properties, vegetative growth and yield of apple plants grown on vertisol under Cacak conditions (Western Serbia). The results showed that the combined fertilization induced a decrease in acidity, an increase in humus content, a partial increase in total nitrogen (NTOT), and, primarily, a rise in available phosphorus (P) and potassium (K) levels. A highly significant (P < 0.01) interactive effect of the apple cultivars and nutrients on one-year-old shoot length and trunk cross-sectional area (TCSA) and a significant effect (P < 0.05) on yield per tree and yield per hectare were determined.

Sustainable land management requires that water and matter (nutrients and base cations) are efficiently recycled within ecosystems so that irreversible losses of matter from topsoils are minimised. Matter losses are connected to water flow. The division of water into evapotranspiration that is loss-free, and seepage to groundwater or surface water flow that both carry material losses, is decisive in determining total losses of dissolved matter in a given catchment. Investigations of areal matter losses confirmed the instrumental role of vegetation cover. Areal matter losses measured in agricultural catchments in Germany were on average between 1-1.5 tons of dissolved matter per ha per year, i.e. some 50 to 100 times higher than those from unmanaged land in a virgin forest. Such high losses continuously reduce soil fertility and can hardly be compensated by fertilisation. Some suggestions on how to achieve sustainable management of agricultural land and maintain high soil fertility are presented - the priority is to close water and matter cycles through the incorporation of more natural vegetation cover into our landscapes and to restore the energy-dissipative properties of ecosystems.

Plant root and shoot dry weight, leaf relative water content (LRWC) and chlorophyll content were reduced by 30%, 21%, 15%, 34%, respectively, at 40mM NaCl as compared to non-salt stress conditions. However, membrane permeability (MP) of plant increased (85.0%) with increasing salinity. Foliar nutrient application (FNA) alleviated deleterious effects of salinity stress on growth and this effect was statistically significant. The highest alleviation effect of FNA at 40mM salinity stress was observed in the case of 10mM foliar KNO₃ and Ca(NO₃)₂ application, resulting in increase in plant root dry weight (50%), shoot dry weight (50%), LRWC (8.2%) and MP decrease (27.4%) at 40mM NaCl. Phosphorus, Fe and Zn contents in shoots and roots of plants also increased with FNA treatments, but they were still much lower than those of non-salt stress treatment. Sulphur, P, Fe and Zn contents of shoots reached similar values as in non-salt stress treatment when KNO₃ was applied, whereas Fe, Mn, Zn, and Cu contents of roots reached the values of non-salt stress treatment when Ca(NO₃)₂ was applied.

This paper presents the results of a three-year research on the effect of perforated polyethylene foil and polypropylene fibre covers on the growth of early potato cultivars at various lengths of plant covering period (2 and 3 weeks after plant emergence). Plants grown under covers were higher, produced higher mass of above-ground parts, and were characterised by a smaller value of leaf weight ratio (LWR) and leaf area ratio (LAR) compared with the cultivation without covering. In the case of plant covering for 2 weeks after emergence the mass of leaves at the time of cover removal was on average almost 2 times higher and the mass of stems over 2.5 times higher than in the cultivation without covering; the values of LWR and LAR were however smaller by 0.094 and 0.137 m

The CULTAN (Controlled Uptake Long Term Ammonium Nutrition) system is based on one-time injection of the whole dose of nitrogen required for the vegetation period. The effect of this method on yield and grain quality of winter wheat was observed in a 2-year small-plot trial at 4 different experimental sites in the Czech Republic. The experiment comprised two treatments with the total amount of nitrogen applied during fertilization of 150 kg N/ha. At the CULTAN treatment the whole dose was applied all at once using the GFI 3A injection machine (Maschinen und Antriebstechnik GmbH Güstrow), whereas at the control treatment, the dose was divided into three applications. The average grain yield of winter wheat in 2007 was 9.56 t/ha (control) and 8.78 t/ha (CULTAN); in 2008 it was 9.91 t/ha (control) and 9.63 t/ha (CULTAN). The differences in 2008 were not statistically significant. The contents of nitrogen and gluten were significantly lower at CULTAN treatment in both years. The values of falling number, Zeleny test and bulk density were generally similar at both treatments.

Soil micromorphology was applied to specify flow domains in different soils and to select a suitable numerical model for simulation of water flow and herbicide transport. Pore structure detected on soil micromorphological images represented in all cases domains of prevailing water flow and solute transport. Depending on pore configuration and boundary conditions either water immobilization or preferential flow was observed and simulated. The benefits and limitations of the soil micromorphology imaging are discussed and compared with the more often used X-ray computer tomography, magnetic resonance imaging and dye tracer imaging.

Soil samples (from Czech and German long-term field experiments) were used to estimate different soil phosphorus (P) fractions. More than 200 topsoil (0-30 cm) samples from different fertilizing treatments were taken. These were analyzed for P in soil solution (P_CaCl2) [0.01M CaCl₂ extract], exchangeable sorbed P (P_ex) [anion exchange (AE) membranes] and bioavailable P [Doppel-Lactat and Mehlich 3 (P_DL and P_M3)]. Other fractions analyzed were total inorganic (P_in), total (P_M-tot) and organic (P_org) P [fractionation after Marks], P sorbed on Fe and Al (P_FeAl) [fractionation after Schwertmann] and residual P (P_ar) [aqua regia extract]. Comparison of medians appeared to be better for evaluating extraction abilities. Phosphorus fractions were in the following order: (P_ar = 100%); P_CaCl2 (0.2%) < P_ex (9%) < P_DL (10%) < P_M3 (16%) < P_in (24%) < P_org (37%) < P_FeAl (55%) < P_M-tot (59%). Low amounts of P_in, P_org and P_M-tot did not verify the applicability of the Marks' fractionation for the set of studied soils. Close correlations at P ≤ 0.001 were found for all methods for estimating the fractions of bioavailable phosphates (P_CaCl2, P_ex, P_DL and P_M3). Statistically significant relations were observed between P_in with P_ar, P_M-tot and P_FeAl.

Citrulline has been recently shown to behave as a novel compatible solute in the Citrullus lanatus (Cucurbitaceae) growing under desert conditions. In the present study we have investigated some aspects of the relationship which might occur in leaves of melon seedlings, also known to produce citrulline, between the capacity to accumulate this ureido amino acid and salt tolerance. With this end in view, salt-induced changes at the citrulline level have been compared in two melon genotypes exhibiting contrasted abilities to withstand the damaging effects of high salinity. Progressive salinization of the growing solution occurred at 23 days after sowing. The final 250 mmol/l external NaCl concentration was reached within 5 days and further maintained for 16 days. In response to this treatment, it was found that the citrulline amount increased in fully expanded leaves of both genotypes according to different kinetics. The salt tolerant genotype Midyat was induced to accumulate citrulline 4 days before the salt sensitive Yuva and as a consequence the final amount of this amino acid was twice higher in the former than in the latter. Compared with citrulline, the free proline level was found to be relatively low and the changes induced in response to the salt treatment exhibited different trends according to the genotypes under study. Thus at the end of the treatment mature leaves of the salt sensitive Yuva contained higher amount of proline than those of Midyat. The changes in the calculated molar ratio between citrulline and free proline suggested that salt tolerance might be associated with high values for this ratio and vice et versa for sensitivity. The interest of citrulline as a biochemical marker for salt tolerance of melon genotypes is discussed.

An incubation experiment with addition of EDTA and alfalfa into soils contaminated with heavy metal over 200 years was carried out in order to evaluate the EDTA effects on microbial properties. Alfalfa was added to soils together with EDTA to examine its abilities to improve microbial activities affected by EDTA. The obtained results showed that the addition of EDTA led to a significant decrease of microbial biomass C during the first 24 days of incubation. At the end of the experiment the microbial biomass C significantly increased quite close to the original level. The EDTA amendment caused, probably due to the toxic effects, a significant increase in respiratory activities and of the metabolic quotient qCO₂. An addition of alfalfa significantly improved the microbial biomass C contents in arable soils treated together with EDTA. Both, respiratory activities and qCO₂ significantly increased after the soil treatment with EDTA together with alfalfa. EDTA alone decreased the microbial biomass, alfalfa alone as organic substrate was mineralised and utilised by soil microorganisms for their metabolism.

Ecobiological study of medicinal plants includes the analysis of particular soil features and the ecological indexes of plant species as site indicators. Two experimental serpentine areas in northwest and central Serbia were selected to identify the potential limiting factors for medicinal plant harvesting. Soil analysis is done according to ICP methodology - ICP Forest Manual, Part III, Soil Sampling and Analysis (1998). Floristic and phytocoenological investigations were carried out by Wasthoff-van der Maarel (1973). The assessment of soil quality is based on the calculation of indicator values of available nitrogen (N), heavy metals, and the sensitivity to acidification. According to our results, N (12.1-17.5), acidification (7-12), and indicator values for some heavy metals (0.3-46.5) show a low biological availability. Medicinal plant species at the investigated areas have low values of ecological indexes: N (2.41-2.82), moisture (2.45-2.70) and soil acidity (3.35-3.70). Hydrothermic conditions indicate the predominant presence of sub-xerophytes, semi-sciophytes and mesothermic species. These types of plant species are recommended for exploitation.

The results of three-year trials (1999 to 2001) conducted with six winter wheat varieties in which was investigated the effect of sites, years and varieties on the final grain yield and technological quality showed statistically significant differences (LSD, 95%) among sites in grain yield and these parameters of quality: test volume mass, wet gluten content, sedimentation test, protein content, falling number and flour water absorption capacity. As to the quality, the Žatec site showed itself as generally most suitable, and the Jaroměřice site as the least suitable one. Climate conditions showed a statistically significant effect (LSD, 95%) on grain yield and all quality parameters, beside the percentage of complete grains and swelling capacity of gluten and falling number, which were insignificant. The most favourable weather conditions, a lot of precipitation and high temperature in the course of ripening from three years were proved in the year 2000. Among the varieties were statistically significant differences (LSD, 95%) in grain yield and these parameters of quality: test volume mass, thousand grain weight, ash content, percentage of complete grains, sedimentation test, protein content, reologic properties of dough and baking tests. From the six varieties the best profits were shown from variety Sulamit (loaf volume 595 ml/100 g of flour), the worst was Semper (loaf volume 543 ml/100 g of flour) and Vlasta (loaf volume 532 ml/100 g of flour). The best grain yield was in 2001 (average of sites 8.84 t/ha) and the variety Semper had the highest grain yield of 9.17 t/ha, that is higher at 13.41% compared with Sulamit (7.94 t/ha).

We conducted a pot experiment to evaluate the Cd and Zn accumulation in leaves and roots of Salix smithiana (BOKU-03DE-001) and S. caprea (BOKU-01AT-004) clones grown on a metal-contaminated soil as affected by native microbes extracted from the same experimental soil, and the fungus Cadophora finlandica. Plant biomass production of S. smithiana was decreased in all the treatments compared to the sterilized control. In contrast, S. caprea grew best on the non-sterilized soil. Similar effects were observed for plant Zn and Cd contents. Microbial treatments affected metal accumulation differently in the two Salix species. The effects of the microbial treatments on biomass and metal content of leaves were not related to the degree of mycorrhization. A comparison with literature data suggests that the plant response to microbial inoculation in terms of metal accumulation may depend on the plant-internal metal concentration. Our findings also illustrate a difficulty of successful rhizosphere management using metal-tolerant microbial isolates to further enhance the phytoextraction process.

Our objective was to determine which rhizome extract from Japanese knotweed, Giant knotweed or Bohemian knotweed has the most significant inhibition effect on the germinated seeds. The seeds of white mustard were incubated with the extracts for two days under laboratory conditions. We monitored differences in number of germinated seeds, length of radicles, hypocotyls and root/shoot ratio between the control and experimental seeds. Inhibitory effect of extracts from dried knotweed rhizomes was confirmed, but without differences among tested plants. A higher allelopathic effect was revealed in the case of extract from aboveground parts.

Basmati rice (Oryza sativa L.) cultivars viz. PRH-10 (pusa rice hybrid-10) and PS-2 (Pusa Sugandh-2) were grown under two different day/night temperatures (31/24°C, 35/28°C) at ambient (370 μmol/mol) and elevated (550 μmol/mol) carbon dioxide (CO₂) concentration, respectively, to characterize how an increase in CO₂ and temperature affects rice photosynthesis and carbohydrate metabolism. At elevated CO₂, the photosynthetic rates increased under both the temperature regimes, compared with plants grown at ambient CO₂. The photosynthetic rate, sucrose-P synthase (SPS) activity and accumulation of soluble sugars and starch were higher in PRH-10 (pusa rice hybrid-10), compared to PS-2 (Pusa Sugandh-2). Elevated temperature decreased the photosynthetic rates both under ambient and elevated CO₂ conditions. The SPS (sucrose-P synthase) activity and the accumulation of soluble sugars and starch were enhanced at elevated CO₂ under both temperature regimes compared with plants grown at ambient CO₂. The up-regulation of SPS (sucrose-P synthase) under elevated CO₂ and temperature would be beneficial for growth and productivity of rice plants for the future climatic conditions.

Significant quantities of Cd have been added to soils globally due to various anthropogenic activities, posing a serious threat to safe food production and human health. Rhizosphere, as an important interface of soil and plant, plays a significant role in the agro-environmental system. This article presents a review of relationship between root excretion and microorganisms and plant resistance to Cd toxicity and possible mechanisms. Root exudates markedly altered in species and quantity under Cd stress. Root exudates can affect Cd absorption by plants through changing the physical and chemical characteristics of rhizospheres. The influence of root exudates on Cd bioavailability and toxicity may include modifying the rhizosphere pH and Eh, chelating/complexing and depositing with Cd ions, and altering the community construction, the numbers and activities of rhizospheric microbes. In this paper, the methods to reduce the transfer of Cd in soil-plant system by adjusting rhizosphere environment are discussed, and some aspects are also proposed that should be emphasized in the future research work.

Microbial activities and counts of microorganisms were monitored as a part of research projects at 11 localities on arable land of different soil types during the years 2002-2006. The counts of microorganisms (total bacteria count, actinomycetes, micromycetes, Azotobacter, oligotrophic and spore-forming bacteria) and microbial activities (respiration, ammonification and nitrification tests) were evaluated using summary statistics, analysis of variance and correlation coefficients. The average counts of microorganisms corresponded with usual counts of microbes in arable soils. There were only some differences among localities in Azotobacter counts. Soil respiration is very often used as an indicator of soil microflora activity. Average values of basal respiration were slightly lower (0.45 mg CO₂ /h per 100 g dry soil) than usual values, potential respiration with glucose (G) or with ammonium and G (NG) responded to usual values (average G 4.27, NG 9.53 mg CO₂ /h per 100 g dry soil). All activities (except actual ammonification) were higher in spring season, but the differences were not significant. There were significant differences in correlation coefficients among the selected criteria; 66% from the total number of correlation coefficients were non-significant, 34% were significant (13% of them was at the significance level 0.05, 10% P < 0.01, and 11% P < 0.001).

The experiments were conducted to study the effects of arsenic-contaminated irrigation water, zinc and organic matter on the mobilization of arsenic in an Aeric Endoaquept in relation to rice (cv. IET 4786). The results show that the amount of extractable arsenic increased with the progress of submergence decreased with zinc application. The magnitude of such decrease varied with the Zn amount, being greater (0.70 to 1.08 mg/kg) in the treatment where zinc was applied at the rate of 20 mg/kg. With regards to organic matter application, the arsenic content in soil markedly decreased, especially with farmyard manure application. The results of the greenhouse experiment with exposure of graded doses of arsenic to rice suggest that the upper toxic limit of arsenic in soil was 10 mg/kg for rice. The results of the field experiment show that the grain yield of continuous flooding (4.84 t/ha) and intermittent flooding up to 40 days after transplanting followed by continuous flooding (4.83 t/ha) with the application of ZnSO₄ at the rate of 25 kg/ha did not vary significantly. The lowest grain yield (3.65 t/ha) was recorded in the treatment where the intermittent flooding was maintained throughout the growth period without the application of zinc. The amount of arsenic was, however, much lower in the treatment where intermittent flooding was maintained throughout the growing period combined with zinc sulphate application.

In the present study, the effects of fungicide Aliette WG 800 [80% fosetyl-Al (aluminium tris-o-ethyl phosphonate)], widely used against Phytophtora infestans on tomatoes grown in greenhouse in Turkey, were studied on the morphology and viability of tomato (Lycopersicon esculentum Mill.) pollens. The fungicide was applied to tomatoes grown in greenhouse at recommended dosage (200 g/100 l water) and at double the recommended dosage (400 g/100 l water). The fungicide caused changes in the morphological structures of tomato pollens. Some pollen morphological structures that are not observed in the control group were encountered in the pollens in equatorial view and in polar view at 200 g/100 l treated groups. On the other hand, pollen viability level decreased as the dosage increased. Especially, non-viable pollen types such as wrinkled pollen or pollen with abnormal shape were encountered in the fungicide groups. It was expected that the pollen fertility as well as yield would decrease in future.

Formerly arable luvic chernozem set aside for ten years (1997-2006) with different herbaceous cover (grass, legumes and their mixtures) and agronomical practices (mulching and cut/harvesting) was studied. The experimental plot was maintained as black, spontaneous and controlled fallows from 1997 until July 2003 (BD period). In July 2003 the plots were desiccated by glyphosate herbicide and were run as a black fallow until August 2004 (AD). The last period (AG) was characterized by monoculture of Italian ryegrass cut/harvested twice a year until October 2006. The experimental soils were characterized with 18 parameters. Mulched plots in all periods (BD, AD and AG) were evaluated as highly microbial active plots. The black fallow (BD) permanently maintained by glyphosate herbicide was the lowest in biological parameters. The desiccation caused a highly significant increase (P < 0.01) of nitrates in topsoil, but in following period (AG) their significant decrease was detected. Desiccation enhanced carbon immobilization into microbial cells especially on mulched and cut/harvested sites (BD, AD). Due to mulching accumulation of soil organic matter highly significantly increased (P < 0.01). This induced a highly significant (P < 0.01) increase in the basal respiration (AD, AG) as the soil organic matter accumulated in the period BD was intensively mineralized.

Urbanization has drastically changed soil properties, and an assessment of these changes is essential for soil management and soil health. The activities of urease, acid phosphatase, invertase and catalase, soil organic matter, pH, electrical conductivity (EC) and clay (< 0.01 mm) content of urban soils under two land-uses in the central built-up area of the Shenzhen city were investigated, and multivariate analysis was used to study the relationship between soil enzymes and soil physical-chemical properties. The results showed that invertase activity in roadside soil was significantly higher than that in urban park soil, whereas catalase activity was significantly higher in urban park soil. Soil organic matter had significant positive correlation with activities of invertase, urease and acid phosphatase but not with catalase. Soil pH had a significant negative direct effect on urease and acid phosphatase activity, but the effect was counteracted by positive indirect effect of soil organic matter. Soil EC had a positive direct effect on activities of catalase and there was a significant correlation between soil EC and soil catalase activities. Soil organic matter, soil pH and EC were the major factors influencing activities of soil enzymes.

By reference to the Eternal Rye trial in Halle, Germany, as an example, it is demonstrated that long-term trials provide indispensable information for contemporary and future land use research. These trials serve as tools for the examination of cultivation measures or the effects of climate on nutrient dynamics and mobilization, microbial biodiversity, mineral composition or soil formation processes. They are therefore essential for the evaluation of land-use strategies or climatic change and, because of that, can provide more accuracy in related political considerations.

The effects of different concentrations of copper (0-800 μmol) on growth, protein contents, peroxidase (POD), catalase (CAT), superoxide dismutase (SOD), and phenylalanine ammonia-lyase (PAL) in Jatropha curcas L. seedlings were assessed by means of pot experiments. Results suggested that increased copper concentrations lead to decreased shoot elongation and seedling biomass. Protein content in the leaves and roots reached their highest levels at the copper concentrations of 400 μmol, while the highest protein content in the stem was observed at 800 μmol copper. POD activity in leaves and stems was unaffected at low copper concentrations, but showed a considerable variation at high copper concentrations. In roots, the highest POD activity was observed at 200 μmol copper. Under copper stress, SOD activity in leaves increased concomitantly with increasing copper up to 400 μmol, and SOD activity in stems and roots showed a slight increase. Catalase activity significantly elevated in leaves and roots but showed no significant changes in stems of the seedlings exposed to copper. A gradual increase of PAL activity in leaves and roots at the copper concentration of 400 and 200 μmol was observed, while PAL activity remained unchanged in stems.

Chlorophyll a fluorescence measurements were carried out on two barley (Hordeum vulgare L.) cultivars Arabi Abiad and Arabi Aswad at 8 and 14 days after emergence to identify their early tolerance mechanism for heavy metals (25 and 50μM of cadmium and lead). Transient fluorescence curves (OJIP curves) and energy flux models showed different specific reactions of photosystem II (PSII) of each cultivar to each type of stress. After 7 days of lead stress application plants of cv. A. Aswad showed weaker I and P peaks on the OJIP curve than control plants, and the appearance of a new K step; parameters of phenomenological energy fluxes for cv. A. Abiad were similar to those for control plants and only some silent reaction centers appeared. Generally, parameters of energy fluxes within PSII were directly shifted shortly (24 h) after the application of both heavy metals, especially in the case of plants grown under cadmium treatment. This suggests that these parameters could be good indicators for monitoring of these two pollutants in the environment at early stages of plant development.

Pot experiments were conducted to determine the best time for application of (ethylenediaminetetraacetic acid) EDTA and sheep manure extract (SME) in phytoremediation of a contaminated soil by Helianthus annuus. The plant was grown in a mine calcareous soil treated with increasing concentrations of EDTA or SME in 30 and 10 days before sowing (T1 and T2) and 10 and 30 days after sowing (T3 and T4). The best time for EDTA application was T4. The EDTA application before seed germination significantly reduced sunflower seedling emergence and dry weight. Soil available Pb and lead concentrations in plant organs increased with EDTA concentration but the actual amount of phytoextracted Pb decreased at high EDTA concentrations significantly, due to severe growth depression. SME application after sowing can increase plant dry weight and Pb concentration in the soil solution, enhancing the accumulated metal concentrations in shoots and roots. However the results showed that the most efficient treatments for Pb phytoextraction by sunflower are applications of 0.5 and 2 g EDTA/kg soil at T3 and T4, respectively.

The paper deals with the possibilities of arsenic analysis in the soil. The aim is the selection and verification of the methods for analysis of As in the soil, which seem to be suitable for risk evaluation based on the increased As soil load. Economical and analytical availability of the methods is an important criterion. A sample set of 6 heavily contaminated soils was used to compare application potential of prevalent as well as less common procedures for determination of arsenic forms in soils. The results showed that substitution of analytically more demanding As total content analysis and sequential analysis for simple extraction using one-off agents seemed to be promising in many cases. The comparison and evaluation of statistical correlation of used methods of As analysis in the soil was realised. The results suggested that using the combination of simple 1M NH₄NO₃ extraction and determination procedure for amorphous Fe forms in the soil (the Tamm method) was suitable for the risk assessment stemming from the As contamination without necessity of the application of more complicated sequential extraction procedures.

Several fusarioid microorganisms were isolated as potential pathogens of hop (Humulus lupulus L.) but their virulence was not proved in inoculation trials in field conditions. Molecular search for other possible pathogens was then performed. Using terminal restriction fragment length polymorphism (TRFLP), Gibberella pulicaris (anamorph: Fusarium sambucinum) was identified as a probable cause of the hop wilting. The primary cause of the disease is wounding of hop crowns by feeding of rosy rustic moth (Hydraecia micacea) caterpillars or by defect pruning and other unfavourable circumstances. The specific primer HLf1 was designed that can be used to detect the pathogen in soil and in damaged plant tissues.

This study aims to investigate the changes in isotope ratios in foliage and soils of the two spruce forests [Picea abies (L.) Karst.] differing greatly in their atmospheric N deposition and climatic conditions. As expected, both N concentrations and ¹⁵N values in both needles and litter were found to be significantly higher in the Solling stand (N-saturated) compared to the Hyytialä stand (N-poor). For the N-limited site (Hyytialä plot), a typical vertical gradient of the soil ¹⁵N-enrichment (both in organic and mineral soil) was observed. The N-saturated site (Solling) differs from the N-limited site (Hyytialä) with respect to the ¹⁵N abundance trend in organic layer. In the upper organic layer up to O-f horizon, i.e. mor layer (0-3.5 cm depth) of Solling plot, there is almost a trend of slight soil ¹⁵N-depletion with increasing depth, and then there is a ¹⁵N-enrichment from O-h horizon (humus layer) of organic layer to mineral soil horizons. This is explained by the presence of prominent NO₃^- leaching at this plot