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Low application of fertilizer potassium (K) in intensive agriculture leads to a gradual decrease and, afterwards, to a steady state of soil K determined by tests which are based on soil exchangeable K (K_exch) extraction. In this situation, non-exchangeable K (K_non-exch) is being released and therefore real plant availability does not necessarily correspond to soil test K. This incoherency was investigated in 14 agricultural soils with low K as determined by the Mehlich 3 method. Plant-available K released by exhaustive cropping of perennial ryegrass and K determined by the Neubauer seedling test were compared with 8 soil K extraction methods, with the total K content and with the relative content of soil K-bearing minerals. K determined by the ryegrass test (314 mg/kg on average) was more than 3-times higher than K based on K_exch extraction methods, but was from 2 to 3 times lower than K determined by K_non-exch extracting methods. The relative content of mixed-layer phyllosilicates was significantly related to K extracted by soil tests. The relative content of orthoclase correlated only with total K and mica-group minerals with none of the extractions. The best prediction of plant-available K in investigated soils was obtained with sodium tetraphenylboron and StepK methods.

Plant's nitrogen (N) requirement that is not fulfilled by available N in soil has to be supplied externally through chemical fertilizers. A reliable estimate of soil N-supplying capacity (NSC) is therefore essential for efficient fertilizer use. In this study involving a pot experiment with twenty acidic soils varying widely in properties, we evaluated six chemical indices of soil N-availability viz. organic carbon (C_org), total N (N_tot), acid and alkaline-KMnO₄ extractable-N, hot KCl extractable-N (KCl-N) and phosphate-borate buffer extractable-N (PBB-N), based on their strength of correlation with available-N values obtained through aerobic incubation (AI-N) and anaerobic incubation (ANI-N), and also with the dry matter yield (DMY), N percentage and plant (maize) N uptake (PNU). In general, the soils showed large variability in NSC as indicated by variability in PNU which ranged from 598 to 1026 mg/pot. Correlations of the N-availability indices with AI-N and ANI-N decreased in the order: PBB-N (r = 0.784** and 0.901**) > KCl-N (r = 0.773** and 0.743**) > acid KMnO₄-N (r = 0.575** and 0.651**) ≥ C_org (r = 0.591** and 0.531**) ≥ alkaline KMnO₄-N (r = 0.394** and 0.548**) > N_tot (r = 0.297** and 0.273*). Of all the indices evaluated, PBB-N showed the best correlations with plant parameters as well (r = 0.790** and 0.793** for DMY and PNU, respectively). Based on the highest correlations of PBB-N with biological indices as well as plant responses, we propose PBB-N as an appropriate index of N-availability in the acidic soils of India and other regions with similar soils.

The purpose of the studies was to determine the microorganisms communities in the soil under scorzonera cultivation with the cover crops using. The greatest total CFU of bacteria occurred in the soil from the experimental combination where oat ploughed over in spring or autumn was the cover crops. The smallest total CFU of bacteria was obtained after ploughing over the mulch of tansy phacelia. The use of oats and spring vetch had a positive effect on the population of bacteria from the genera of Bacillus and Pseudomonas. The smallest CFU of fungi was obtained from the soil where oat constituted the mulch. Alternaria alternata, Fusarium oxysporum, F. culmorum, Haematonectria haematococca and Thanatephorus cucumeris were most frequently isolated from the soil. The most isolates of the enumerated fungi were obtained from the soil cultivated in a conventional cultivation and after ploughing over the mulch of tansy phacelia plants. The most antagonistic bacteria and fungi occurred in the soil after ploughing over the mulch of oat, while the least in the conventionally cultivated soil.

The aim was to compare the efficacy, selectivity to sunflower and dissipation of three chloracetamide herbicides (acetochlor, metolachlor and pethoxamid) in dependence on precipitation after application. A small plot field trial was carried out with sunflower in Central Bohemia in 2010 and 2011. The remaining concentration of active ingredient in the soil of all studied herbicides was lower in the year with a higher temperature and a low level of total natural precipitation at the beginning of the growing season. Higher leaching of metolachlor and pethoxamid was recorded in irrigated plots. No leaching was found in the case of acetochlor. The highest leaching was found for metolachlor (9.2-25.5% in soil layer 5-10 cm). The highest phytotoxicity was found for acetochlor (9.8%) > pethox-amid (4.6%) > metolachlor (1.8%). The mean phytotoxicity in the irrigated plots was 6.9%, compared with 3.9% in the non-irrigated plots. The efficacy of the tested herbicide was affected by wet conditions. The highest efficacy on Chenopodium album, Amaranthus retroflexus, Echinochloa crus-galli and Solanum physalifolium was recorded after application of acetochlor and irrigation.

Four peanut (Arachis hypogaea L.) cultivars (cvs. TPT-1, TPT-4, JL-24 and TMV-2) were grown in open-top chambers at 350 and 600 µmol CO₂/mol in soil amended with 0 (control), 50, 100 and 200 mmol solutions of NaCl. The net photosynthetic rate (P_n), stomatal conductance (g_s), transpiration (E) and dry biomass of leaf, stem and root were measured on 60 days after sowing. The plant growth and photosynthesis increased in both NaCl treated and control plants with elevated CO₂. The g_s and E decreased under elevated CO₂ and the CO₂ effect was highly significant under salt stress mitigating the adverse effect on these components in all the four cultivars tested. A positive correlation was observed between P_n and dry biomass under elevated CO₂ and salt stress. Enhanced CO₂ helps to increase growth and photosynthesis in peanut cultivars and it ameliorates the adverse effects induced by salt stress.

To investigate the ecological safety of Beauveria bassiana in soil, we evaluated the effects of different concentrations of B. bassiana spores suspensions and acephate on paddy soil microbial flora and enzyme activities in a potted trial. Results showed that B. bassiana can increase the quantity of bacteria and fungi on day 10 and 30, while it showed inhibition on actinomycetes growth on day 10. However, acephate reduced the quantity of bacteria, fungi, and actinomycetes in soil. Investigation of enzyme activities revealed that invertase activity declined during prophase, while urease activity decreased later in B. bassiana treatment groups, and there were no significant changes in alkaline phosphatase or dehydrogenase activity. Acephate showed higher inhibition rates of enzymes. B. bassiana treatment at lower concentrations showed a higher yield. Overall, compared with the acephate, B. bassiana is an effective, environmentally friendly microbial pesticide in this system.

Phosphorus (P) availability limits crop growth in most of cultivable soils in north-west India. The beneficial rhizosphere microorganisms such as phosphate-solubilising fungi (PSF) were found to increase P availability in soil and improve crop yields. In view of this, field experiments were conducted during 2009-2011 to evaluate the effect of seed inoculation with PSF (Penicillium bilaii) at different rates of fertilizer P on P content in leaves and grain yield of irrigated wheat in India. The soil was low in Olsen P at the Bathinda site and medium at the Ludhiana site. In no-P treatment, PSF significantly increased grain yield by 12.6% over non-inoculated control. The effect of PSF on grain yield was generally more pronounced in a soil with low Olsen-P compared to medium Olsen-P level. Inoculation of PSF along with 50% P fertilizer increased wheat yield equivalent to 100% P with no PSF. Spike density was significantly higher in PSF + 50% P than all the other treatments. There is need to study a long-term effect of Penicillium bilaii on P-fertilizer saving in wheat on soils varying in P availability, pH and P fixation capacity for different wheat-based cropping systems.

The growth and yield response of spring wheat to inoculation with foreign and local rhizobacteria of Erzurum (Turkey) origin was studied. At the first stage of the research, a greenhouse experiment was carried out with wheat cv. Kirik using 75 local bacterial strains isolated from the soil with 6 foreign bacteria, and a control. According to results of the greenhouse experiment 9 local strains were identified. At the second stage, the response of wheat cv. Kirik to 20 treatments (9 local strains, 6 foreign bacteria, 4 levels of N, and a control) was investigated in Erzurum field conditions. Seventeen strains had significant positive effects on tiller number per plant, 47 strains on plant height, one strain on dry matter yield, and 28 strains on plant protein content in the greenhouse experiment. Inoculation with certain rhizobacteria clearly benefited growth and increased the grain and N-yield of field grown wheat. The effects of local strains were observed to be in general superior to those of foreign strains. Inoculation with the local Strain No. 19, 73, and 82 increased total biomass by 18.7, 18.1, and 19.9%; grain yield by 18.6, 17.7, and 18.0%; total N-yield by 27.5, 24.3 and 26.0%, respectively, as compared to control. In conclusion, Strain No. 19, 73, and 82 can be a suitable biofertilizer for spring wheat cultivation in areas with similar conditions as in Erzurum. Inoculation with these strains may lead both to increases in wheat yield and savings of nitrogen fertilizer.

A four-year field experiment was conducted in north-eastern Poland. The aim of the study was to determine the direct and residual effects of increasing doses of meat and bone meal (MBM) on the available phosphorus content of soil and the total phosphorus content in crops above ground biomass or grain. Experimental factor I was MBM dose (1.0, 1.5, 2.0 and 2.5 t/ha/year, and 2.0, 3.0, 4.0 and 5.0 t/ha/every second year), and experimental factor II was the year of the study (four consecutive years). The application of increasing MBM doses to slightly acidic soil insignificantly decreased its pH, but it did not change soil classification. The use of MBM as a fertilizer increased the levels of available phosphorus, compared to the treatments with mineral fertilization. The grain of winter triticale and winter wheat and the green matter of maize contained higher concentrations of phosphorus after the MBM application, in comparison to the plants receiving mineral fertilization. Phosphorus uptake by winter wheat and maize plants (dry matter basis) was higher in treatments with MBM (in particular applied every second year) than in treatments with NPK fertilization. Irrespective of the frequency of MBM application, phosphorus uptake by winter rapeseed was considerably lower, compared to the control plants.

In the present study, three soils (Ferralsol, Luvisol topsoil, and Luvisol subsoil) were amended with biochars (charcoal, hydrothermal carbonization coal (HTC) of bark, and low-temperature conversion coal of sewage sludge), wheat straw and a control (no amendment) and incubated over a period of 365 days. Each amendment was applied at a rate of 11.29 g C/kg soil. After incubation, the soils were analyzed to retrieve three density fractions (free fraction (FF), intra-aggregate fraction (IAF), and heavy fraction) which were analyzed for total carbon (TC) contents and scanned by fourier transform infrared spectroscopy (FTIR). The biochars and straw significantly increased the TC contents of soils as compared to control. Among soil organic matter (SOM) density fractions, higher TC contents were documented in the FF and IAF from biochar treatments as compared to the straw. The FTIR spectra of the FF from the charcoal and HTC treatments showed the presence of aluminosilicate minerals on surfaces of SOM. There were slight changes in the FF of straw and HTC treatments as compared to spectra of original amendments. The study suggests that the stability of charcoal and HTC in soils is due to the recalcitrant nature of biochar followed by occlusion into soil micro-aggregates.

Tested soils (1991-2002) were defined by chemical, textural and microbial characteristics. From the tests which describe cambisols, the following parameters have to be stressed. The higher level of C_org (1.20-1.76%), which resulted in quite high microbial biomass carbon content (396-625 µg/g dry soil), high control respiration (0.45-0.80 mg CO₂/h/100 g dry soil) and potential nitrification with (NH₄)₂SO₄ (6.7-18.4 mg N-NO₃/8 days/100 g dry soil). Studied luvisols reached typical levels: C_org (0.97-1.22%), C_MB (398-503 µg/g dry soil), control respiration (0.46-0.57 mg CO₂/h/100 g dry soil), potential nitrification with (NH₄)₂SO₄ (3.2-9.9 mg N-NO₃/8 days/100 g dry soil). Lower levels of organic carbon and a medium level of microbial biomass raised in higher ratio C_MB/C_org (average 4.0%). Highly significant differences (p < 0.01) between cambisols and luvisols were determined for C_org, N_t, pH(KCl), C_MB, C_MB/C_org, C_E, control respiration and potential nitrification, while the difference in potential ammonification with peptone was at level p < 0.05. With the exemption of ratio C_MB/C_org all cambisol characteristics were higher than luvisol ones. Studied soils were evaluated by six biological criteria (C_MB; ratios: C_MB/C_org, C_E/C_MB, potential/control respiration, potential/control ammonification, potential/control nitrification). These criteria distinguished tested soils into three groups. The first one includes two localities in the mountain region (Červená Voda 809, 810; altitude 565-590 m) defined as stagnic cambisols with higher content of C_org (1.40, respective 1.76%) and simultaneously with the highest biomass of micro-organisms from all tested soils (C_MB,625, respective 621 µg/g dry soil). It is not surprising that microbial activities (respiration, nitrification) at these localities were also high. The majority of the studied localities (one eutric cambisol and four luvisols) belongs to the medium group. The third group includes two localities (Neumětely - haplic luvisol, Čistá u Rakovníka - eutric cambisol) where biological criteria was mostly the worst. In the period 1993-2002 microbial biomass carbon was for both sites in the range of 357-458 µg/g dry soil which are not so bad values, but in comparison with localities in mountain wet region they are low. This status was issued in the lower ratio C_MB/C_org (2.71-3.77%).

A 10-20% decrease in annual precipitation is predicted in the Mediterranean basin, and in particular to the Iberian Peninsula, with foreseen effects on the exchange of soil-atmosphere greenhouse gases (GHGs; CO₂, CH₄, and N₂O). To simulate this scenario, we setup an experimental design in the particularly dry period of 2008-2009 using rainfall exclusion and irrigation, to obtain plots receiving 110% (538 mm), 100% (493 mm) and 74% (365 mm) of the natural precipitation. Soil CO₂ fluxes showed a strong increase from summer to autumn as a consequence of increasing soil heterotrophic respiration that resulted from rewetting. Fluxes of N₂O were negligible. According to our data, soil was a permanent CH₄ sink independent of the soil water content (in the range between 6-26% WFPS - water-filled pore space) and of soil temperature (in the range of 7-28°C), supporting the concept that seasonally dry ecosystems (Mediterranean) may represent a significant sink of atmospheric CH₄. The study provides evidence that the 26% decrease or 10% increase in the ambient rainfall from annual precipitation of ca 500 mm did not significantly affect soil functionality and had a limited impact on soil-atmosphere net GHGs exchange in evergreen oak woodlands in southern Portugal.

The upper values of the extractability of trace elements (As, Be, Cd, Co, Cr, Cu, Ni, Pb and Zn) in 2 mol/L HNO₃ and 0.025 mol/L ethylenediaminetetraacetic acid (EDTA) (compared with their pseudototal content in aqua regia) for determination of prevailing anthropogenic and geogenic soil load were proposed and compared with the results of the other 30 Fluvisol samples collected from the Labe fluvial zone. The increased geogenic load of Fluvisols was confirmed in the case of Be and As in some localities where low extractability with increased pseudototal contents were detected as opposed to the other elements when their increased pseudototal contents were followed by their increased extractability. The maps of probability of increased geogenic soil load in the area of the Czech Republic based on the comparison of geological substrates and trace element load were constructed. The combination of proposed elements extractability values for geogenic load together with developed maps is a suitable tool for the definition of prevailing Fluvisol or sediment load on some localities in the whole area of the Czech Republic. The results can be also a useful tool in the decision making processes regarding dredged sediment application on agricultural soil (support tool for legislative norms, Direction No. 257/2009 Sb.).

The yield forming response of maize cultivar to zinc (Zn) application depends on its timing. This hypothesis was validated in 2007, 2008, 2009 and 2010 growing seasons. The zinc treatments as the first factor were: NPK; NPK + Zn applied before sowing; NPK + Zn applied to maize at the stage of 4^th leaf. The second factor was the maize type: stay-green (modern cultivars) - Paroli, Veritis, Anamur; classical (old cultivars) - Inagua, Kirola. The grain yield of modern cultivars responded the best to zinc applied before sowing, whereas the old ones, when applied to foliage. The yield of the stay-green maize depended upon the number of kernels per row, whereas the classical one on all yield structural components. The zinc management in the modern cultivars should be oriented towards maximization of the number of kernels per row, whereas in the old one on its optimization with the simultaneous kernel weight increase. The positive impact of zinc application before sowing on dry matter translocation from vegetative tissues to growing kernels underlines its practical usefulness, especially in areas with frequent water shortage during maize growth.

Paddy rice is one of the most important cereal crops in China. Nitrogen (N) is closely related to crops production by influencing the photosynthetic efficiency of paddy rice. In this study, laser-induced fluorescence (LIF) technology with the help of principal component analysis (PCA) and back-propagation neural network (BPNN) is proposed to monitor leaf N content (LNC) of paddy rice. The PCA is utilized to extract the characteristic variables of LIF spectra by analysing the major attributes. The results showed that the first three principal components (PCs) can explain 95.76% and 93.53% of the total variance contained in the fluorescence spectra for tillering stage and shooting stage, respectively. Then, BPNN was utilized to inverse the LNC on the basis of the first three PCs as input variables and can obtain the satisfactory inversion results (R² of tillering stage and shooting stage are 0.952 and 0.931, respectively; residual main range from -0.2 to 0.2 mg/g). The experimental results demonstrated that LIF technique combined with multivariate analysis will be a useful method for monitoring the LNC of paddy rice, which can provide consultations for the decision-making of peasants in their N fertilization strategies.

In the past few years in Europe grass seed production declines. This tendency is especially pronounced in meadow fescue. Seed shedding and therefore yield losses are the problem in seed production. This can be reduced if seed of higher moisture contents is harvested. The impacts of drying temperatures of 70, 60, 50, 40 and 22°C on changes in dormancy and germination of seed harvested with moisture contents of 45, 35 and 25% were observed in the present study. The analysis was done immediately after seed drying, then three months later and eight months later. Seeds with the moisture content of 45% that were dried at 70°C were not dormant at all after harvest, but seeds were damaged, which resulted in reduced germination. Drying temperatures of 40°C and 50°C resulted in maximum germination of seed harvested with 45% moisture after three months. After eight months the best germination of all seeds was obtained at 22°C and 40°C. The seed ageing test confirmed faster deterioration of seeds harvested with higher moisture contents. Seed harvested with 25% moisture and dried at 22°C is the most suitable seed for longer storage.

Cattle slurry is frequently used fertilizer on grasslands, but little is known about its effect on plant species composition. The aim of this study was therefore to assess effect of different application rates of cattle slurry (S0 - 0, S1 - 60, S2 - 120, S3 - 180, S4 - 240 kg N/ha/year) on the plant species composition of three-cut grassland. The study was performed over 6 years on moderately moist upland Arrhenatherion grassland in the Czech Republic dominated by Alopecurus pratensis, Trisetum flavescens, and Poa spp. Species composition recorded in treatments with application of cattle slurry in rate up to 120 kg N/ha/year was similar to the unfertilized control. During first three years, species richness was similar in all treatments and then decreased the most in S4 followed by S3 treatment. Cover of short forbs increased in S0 and decreased with an increase in slurry application rate which supported tall grasses. Application of cattle slurry up to 120 kg N/ha/year can be considered as suitable compromise between maintenance of species rich grasslands and requirements of farmers for sufficient forage production.

Zinc (Zn) is an essential micronutrient for growth and development of almost all organisms and its deficiency severely affects the health of plants, animals and humans. In order to investigate the enrichment of Zn in cereals a pot experiment was performed in two contrasting rice varieties viz., PD16 (zinc efficient) and NDR359 (zinc inefficient) under different levels of zinc regimes such as control (0 Zn), soil application (5 mg Zn/kg soil tagged with 3.7 MBq of ⁶⁵Zn/pot), foliar spray of 0.5% ZnSO₄ at 30, 60 and 90 days (925 KBq of ⁶⁵Zn/pot), soil application (5 mg Zn/kg soil tagged with 3.7 MBq of ⁶⁵Zn/pot) + foliar spray of 0.5% ZnSO₄ at 30, 60 and 90 days (925 KBq of ⁶⁵Zn/pot). Both varieties markedly differ in ⁶⁵Zn accumulation and grain Zn content. NDR359 showed poor translocation efficiency and accumulated relatively less ⁶⁵Zn in all the plant parts. In both rice varieties, highest concentration of Zn in dehusked grains could be obtained with soil application of Zn + foliar spray of zinc sulphate. Though NDR359, a zinc inefficient variety exhibited poor zinc translocation efficiency yet, it contained more Zn content in grains with husk and dehusked grains than PD16.

Partial characterization of iron binding compounds in spinach above ground biomass and differences between binding of Cd, Zn and Fe in spinach biomass were investigated on two soils treated by sewage sludge in model pot experiment. After application of sludge to both soils, Cd and Zn accumulation in spinach biomass was increased in sludge treatments. Total Fe content in biomass showed opposite trend with these treatments and was decreased 2.5-2.7 fold. Results of sequential analysis of spinach biomass showed lower portions of iron in all individual fractions of both sewage sludge treatments compared to control treatments. The largest differences in iron content between control and sludge treatments were determined in ethyl acetate fraction. While majorities of Cd and Zn were found in fractions methanol + H2O and H₂O and methanol + H₂O + HCl, iron content determined in these two fractions was only 7-8% in control treatments and 15-20% in sludge treatments of total iron. In fraction, Fe portion was 87.7-90.7% in treatments without sludge and 76.1-83.5% in sludge treatments in spinach biomass. Results showed tighter iron binding to plant cell membranes in contrast to cadmium and zinc.

Effective weed control in perennial crops is a challenge due to the limited availability of registered herbicides and herbicide resistance. The objective of the study was to evaluate the efficacy of the herbicide GF-2581 (penoxsulam + florasulam) on broadleaf weeds in comparison with other commonly used herbicides. Field trials were conducted in olives, in Etoloakarnania (Agrinio region) for two years (2012 and 2013). Efficacy assessments were made at 30, 60, 90 and 120 days after treatment. The GF-2581 formulation provided excellent control of a broad spectrum of broadleaf weed species. The long-term control of Sonchus oleraceous, Conyza canadensis and Stellaria media, provided by GF-2581 during the growing season was significantly greater than that using flumioxazin. When combined with glyphosate or diquat, the level of control of these three weeds was improved. The GF-2581 agent applied pre-emergence followed 14 days later by application of glyphosate provided 100% control in 2012. Lower efficacy levels were observed in 2013 and may have been the result of higher rainfall when compared to 2012. GF-2581 is an effective herbicide product to control broadleaf weeds, as a part of integrated weed control management strategies in olives.

This work is focused on evaluating the effects of site-specific weed management (SSWM) on weed populations over a 4-year period. SSWM was used on a 3.07 ha experimental field during 2011-2014 in a rotation of winter wheat and winter oilseed rape. The area was split into application cells of 6 × 10 m and weed abundance was evaluated manually in each cell. Four different herbicide treatments were tested. Standard whole-field herbicide application (blanket spraying) was treatment 1. Treatments 2, 3 and 4 comprised SSWM using different thresholds for post-emergent herbicide applications. SSWM resulted in herbicide savings of 6.3-100% for Galium aparine, 0-84.4% for other dicotyledonous weeds, and 31.3-90.6% for annual monocotyledonous weeds. SSWM led to significantly increased density of G. aparine and Tripleurospermum inodorum in the final experimental year when compared to the blanket treatment. Negative correlation coefficients between 2011 and 2014 plant densities found in SSWM treatments (-0.237 to -0.401) indicate that Apera spica-venti does not establish a long-term soil seed bank.

Barley seed sensitivity to water and anoxia was tested. Standard germination, mean time of germination (MTG), germination in sand wetted by water to 100% water capacity (anoxia) or by hydrogen peroxide (wet conditions without anoxia), germination in 0.75% hydrogen peroxide and laboratory emergence (15 and 20°C) were evaluated. Barley seed responds sensitively to stress conditions during germination. Significant germination decrease was found in abundance of water. Percentage of reduction depends on the variety and on the year of seed production. Extreme values of water sensitivity are in interval 4-90%. At wetted sand by 0.75%, solution of H₂O₂ the germination was significantly less reduced. That means that barley seed is very sensitive to oxygen deficiency above all and is less injured by quick imbibition. Heterogeneity in seed vigour was demonstrated in laboratory emergence tests. Quick test of germination in 0.75% hydrogen peroxide deserves attention for its high correlation coefficient with the seed laboratory emergence. The results significantly demonstrate a higher sensitivity of deteriorated seed to germination in abiotic stresses conditions. Variability in speed of germination is increasing, which unfavourably extends the mean time of germination.

Noccaea caerulescens (NC) and Arabidopsis halleri (AH) were studied to compare cadmiunm (Cd) accumulation and resistance. After 30, 60 and 90 days of plant cultivation in Cd contaminated soil (Cd1 = 30, Cd2 = 60 and Cd3 = 90 mg Cd/kg soil) amino acids were determined in plants. The comparison between both species showed that Cd stress resulted in different changes of amino acids levels playing a significant role in plant adaptation to Cd stress. Our analyses indicated higher accumulations of amino acids in the roots of NC compared to AH. Contrasting responses of plants to Cd contamination were confirmed in methionine metabolism. Methionine was determined only in roots of AH after 30 and 60 days of plant cultivation. Free methionine content decreased with increasing Cd contamination (Cd3 treatment - 40% decrease compared to the control treatment). Our results also showed that NC contains more than 10-fold higher content of histidine than AH. These observations indicated that this amino acid may be involved in Cd resistance and accumulation by reducing oxidative damage. Tryptophan plays a major role in the regulation of plant development and in defense responses. Its significant increase for NC treatments in contrast to AH treatments was determined.

he study was undertaken to determine a possible role of polyamines (putrescine, spermidine, spermine) as antioxidants in salt tolerance of Chamomilla recutita and Origanum majorana. Salinity generally induced variable changes in growth, contents of oil and flavonoids of both plants; foliar application of any polyamines counterbalanced the effects of salinity. In general, the degree of stimulation differed according to the type and concentration of the used additive and the type of the plant.

Sequential extractions, metal uptake by Taraxacum officinale, Ruby's physiologically based extraction test (PBET) and toxicity characteristic leaching procedure (TCLP), were used to assess the risk of Pb and Zn in contaminated soils, and to determine relationships among soil characteristics, heavy metals soil fractionation, bioavailability and leachability. Regression analysis using linear and 2nd order polynomial models indicated relationships between Pb and Zn contamination and soil properties, although of small significance (P < 0.05). Statistically highly significant correlations (P < 0.001) were obtained using multiple regression analysis. A correlation between soil cation exchange capacity (CEC) and soil organic matter and clay content was expected. The proportion of Pb in the PBET intestinal phase correlated with total soil Pb and Pb bound to soil oxides and the organic matter fraction. The leachable Pb, extracted with TCLP, correlated with the Pb bound to carbonates and soil organic matter content (R² = 69%). No highly significant correlations (P < 0.001) for Zn with soil properties or Zn fractionation were obtained using multiple regression.

Fruit quality attributes were studied for two consecutive years in seven blackberry cultivars grown in a Serbian climate and on acidic soil. Physical parameters [berry weight (BW), size and shape] and chemical parameters [soluble solids content (SSC), acidity, total phenolic (TPH) and flavonoid content (TFC) and total antioxidant capacity (TAC)] were evaluated. A high variability was found in the set of the evaluated blackberry cultivars and significant differences were found among them in all studied quality attributes. Year-by-year variations were observed for all quality traits, except berry length (L) and berry shape index (BSI). A high correlation was found among TPH and TAC. In addition, most of cultivars had good adaptation capability and respectable fruit quality attributes, and also had good potential as a commercial crop for fresh and processing markets and future breeding programs.

In the paper, the results of the long-term field experiment on soil depletion from potassium on yields and selected indices of nitrogen use efficiency of maize and spring barley were presented. The factors of the experiment were potassium fertilization (K plus and K minus treatment) and increasing nitrogen rates. Maize responded for soil exhausting from K in yield reduction over all the range of nitrogen rates applied in the experiment, and spring barley only through the highest rates. The greater values of nitrogen use efficiency indices were proven for barley as compared with maize. Potassium fertilization slightly increased agronomic efficiency and physiological efficiency of barley.

The objective of the vegetation experiment established in 2008-2011 was to explore the effect of the time and dose of foliar molybdenum (Mo) application on the yield and quality of sunflower. Four treatments were established in the experiment: (1) control - not fertilised with Mo; (2) application of 125 g Mo/ha in the growing stage of 4 developed leaves (V-4); (3) application of 125 g Mo/ha at the beginning of elongation growth (R-1), and (4) split rate of Mo application of 62 g Mo/ha at stage V-4 (4 developed leaves) and 62 g Mo/ha at stage R-1 (terminal bud forms). Foliar application of molybdenum increased the biomass production of sunflower plants and its content in dry matter. A statistically significant effect of molybdenum foliar application on sunflower yields was found. Foliar application of Mo up to a dose of 125 g Mo/ha at the beginning of vegetation (stage V-4) and developmental stage R-1 increased yields of achenes. The relative increase in the oil content after foliar nutrition was not significant and ranged between 1.4% and 2.6%. Oil production increased due to increased yields and stabilised oil content. Foliar application of molybdenum had no effect on the content of oleic acid.

Using a pot experiment with slightly acidic and alkaline soils anthropogenically contaminated by As, Cd, Pb, and Zn, we assessed how the establishment of Bryum argenteum and concentrations of elements (P, Ca, Mg, As, Cd, Cr, Cu, Fe, Mn, Ni, Pb, and Zn) in its biomass are affected by the pH of the substrate, mobility of trace elements, and by quick lime (CaO) and superphosphate (P) additives. Over one vegetation season, in pots naturally colonised by B. argenteum, a substantially higher cover of B. argenteum was recorded on acidic soil that was heavily contaminated with Cd, Pb, and Zn than on alkaline soil with higher As but lower Cd, Pb, and Zn mobility. In acidic soil, the establishment of B. argenteum was substantially improved by CaO additive, which reduced the mobility of Zn and Cd, and by P additive, which improved the P nutritional status and reduced the extremely high concentrations of many elements (As, Cd, Cr, Cu, Fe, Mn, Ni, Pb, and Zn) in its biomass. Although B. argenteum can be used for the monitoring of soil contamination, concentrations of trace elements in its biomass must be evaluated with caution as they can be affected by total and mobile concentrations of elements in the substrate, and by other soil chemical properties.