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This study is aimed at investigating the effect of different vineyard soil management systems on soil erosion and earthworm (Lumbricidae) population. Three soil management systems were investigated: permanent green cover (control), straw-cover and periodic soil tillage. Inter-row periodic soil tillage was applied in 2002 and 2003 (May and August), and straw-cover in May 2002. Periodic soil tillage resulted in increased erosion, i.e. 1746 kg/ha of soil/per year, on average. The greater portion of erosive events occurred after tillage in summer (August 2002), which was accompanied by heavy rainfall and slow renewal of grass cover (slower than in spring). The lowest average amount of soil erosion was observed in the treatment with straw-cover (56 kg/ha per year). This management system provided better environment for earthworm populations, most of which were found close to the soil surface, especially in the dry year 2003. In periodical soil tillage, the majority of earthworms were found in the soil horizon not disturbed by the tillage, i.e. at the depth of 10-20 cm. The lowest number of earthworms (only 2 per m²) was recorded in the herbicide intra-row strip.

Overgrazing affects typical steppe community in ways similar to grasslands in other areas. Exclusion of livestock grazing is one of the main management practices used to protect grasslands. However, it is not known if long-term exclusion of livestock grazing has positive effect on above- and belowground community properties in typical steppe of the Loess Plateau. We studied the long-term (20-year) cumulative effects of exclusion of livestock grazing on above- and belowground community properties compared with that before exclusion of livestock grazing in a typical steppe of the Loess Plateau, NW China. Our results show that twenty-year exclusion of livestock grazing significantly increased above- and belowground biomass, species richness, cover and height for five different communities. Most of belowground biomass was in the 0-20 cm horizon and grazing exclusion increased biomass especially at the depth of 0-10 cm. Our study suggests that long-term exclusion of livestock grazing can greatly improve community properties of typical steppe in the Loess Plateau.

The present investigation was undertaken to find out efficient strains of arbuscular mycorrhiza (AM fungi) alone or in combinations with Trichoderma viride for inoculation Dendrocalamus strictus L. seedlings. The inoculated seedlings showed good response having higher plant height, phosphorous ions content in root and shoot, AM spore number and root colonization than non-inoculated (control) seedlings in both single (alone) and co-inoculation (combined consortium) experiments. T. viride showed significant growth followed by Glomus mosseae, G. fasciculatum and mixed AM with single inoculation. In co-inoculation, the best growth responses were observed with G. fasciculatum + T. viride followed by G. mosseae + T. viride, mixed vesicular arbuscular mycorrhizas (VAM) + T. viride, G. mosseae + G. fasciculatum + T. viride + mixed VAM, G. mosseae + G. fasciculatum + T. viride and G. mosseae + G. fasciculatum after 120 days and also depicted maximum increase in phosphorus content of shoot and root when compared with other inoculated seedlings. However, all the inoculated seedlings showed significant increase in phosphorus content when compared with control seedlings.

Grazing-induced variations in vegetation may either accelerate or reduce soil carbon storage through changes in litter quantity and quality. Here, a three-year field study (2005-2007) was conducted in Tibetan alpine meadow to address the responses of surface soil (0-15 cm) organic carbon (SOC) storage in the plant growing season (from May to September) to varying grazing intensity (represented by the residual aboveground biomass, with G₀, G₁, G₂, and G₃ standing for 100%, 66%, 55%, and 30% biomass residual, respectively), and to explore whether grazing-induced vegetation changes depress or facilitate SOC storage. Our results showed that: (i) Higher grazing intensity resulted in lower biomass of grasses and sedges, lower root biomass, and in a change in plant community composition from palatable grasses and sedges to less palatable forbs. (ii) Increased grazing reduced the SOC content and storage with only G₃ showing an SOC loss during the plant growing season. (iii) Soil organic carbon storage exhibited a highly positive correlation with the residual aboveground biomass and root biomass. Our results imply that a grazing-induced reduction in plant biomass productivity and changes in species composition would depress soil carbon storage, and that an increase in grazing pressure can lead to a gradual change of alpine meadow soils from being 'carbon sinks' to become 'carbon sources'.

The influence of various forms of farming on unmanaged grasslands was monitored with regard to the accumulation of the above-ground biomass (litter + mulching) and its influence on the leakage of rainfall and the amount of elements in lysimetric waters. In 2001-2005, the highest accumulation was observed in variants 1× mulched in the later term and on green fallow (on average 2.11-1.13 t of dry matter/ha). In comparison with the control site, a conclusive increase always occurred. An interannual increase of dry matter amounted to 0.4-5.2% of the total above-ground biomass. A negative correlative dependency on rainfall leakage on this material was discovered; at a depth of 0.4 m 4-10% of the rainfall leaked, but it had a significant influence on the wash out of Ca, Mg and S. The leakage of water affected a wash out of N_min, P, K, Ca, Mg and S more than the weight of dry matter of the above-ground biomass. With the exception of P, the elements showed a downward tendency over five years. The above-mentioned forms of farming annually increased the accumulation of the above-ground biomass by 0.05-0.16 t of dry matter/ha; however, they do not endanger underground waters by washing out minerals. After a five-year period, a disturbance of the ecological stability of grassland did not occur.

In our work, we focus on the evolutionary studies of sex chromosomes. As model organisms we use several species of the plant genus Silene. An important part of our research is represented by genetic mapping based on the assays of DNA length or sequence polymorphisms. Apart from the other methods we also use the dCAPS method, which is very useful for detection of the sequence polymorphisms (SNPs). This method is unique as it is able to detect SNPs that are not situated in any restriction site; a fundamental principle of this method is usage of primer designed with one or two mismatches that bring into the target sequence the mutation in vicinity of SNP. Using this method, we found out some improvements that can make analyses more cost-effective.

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

A 2-year field experiment was conducted under light enrichment and shading conditions to examine the responses of seed yield and yield components distribution across main axis in soybean. The results showed that the maximum increase in seed yield per plant by light enrichment occurred at 27 plants/m², while the most significant reduction in seed yield per plant by shading occurred at 54 plants/m². Light enrichment beginning at early flowering stage decreased seed size on average by 7% while shading increased seed size on average by 9% over densities and cultivars, resulting in a fewer extent compensation in seed yield decrement. Responses to light enrichment and shading occurred proportionately across the main axis node positions despite the differences in the time (15-20 days) of development of yield components between the high and low node positions. Variation intensity of seed size of three soybeans was dissimilar as a result of changes in the environment during the reproductive period. The small-seed cultivar had the greatest stability in single seed size across the main axis, followed by moderate-seed cultivar, while large-seed cultivar was the least stable. Although maximum seed size may be determined by genetic potential in soybean plants, our results suggested that seed size can still be modified by environmental conditions, and the impact can be expressed through some internal control moderating the final size of most seeds in main stem and in all pods. It indicates that, through redistributing the available resources across main stem to components, soybean plants showed the mechanism, in an attempt to maintain or improve yield in a constantly changing environment.

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.

Producers in highland and semiarid regions have difficulty in increasing diversity in crop rotations due to unfavorable conditions imposed by cool temperatures, inadequate rainfall, and shorter growing periods. In such conditions, safflower appears as a promising alternative because it is cold and drought tolerant. The objective of this study was to determine the responses of the hybrid and open-pollinated safflower genotypes to irrigated and non-irrigated conditions in a highland environment. For this reason, the field research was performed during the years of 2001 and 2002 in eastern Anatolia, Turkey. According to the results of the study, safflower genotypes tested were well adapted to the cool and short-season conditions in this region. The response of seed yield to genotype varied depending on the growing seasons. The non-irrigated plants produced nearly the same seed yield as irrigated ones. Average seed yields of safflower genotypes tested were 914.3 and 928.0 kg/ha in 2001, and 1143.6 and 1139.9 kg/ha in 2002 years for irrigated and non-irrigated experiments, respectively. In general, the genotypes differed in all of the investigated traits. In both irrigated and non-irrigated experiments genotype × year interactions were very significant for all parameters. This research shows that in semiarid and highland environments safflower has a big potential value as an oilseed crop under dryland conditions.

In Europe, Rumex obtusifolius L. is the most problematic grassland weed species, especially under the conditions of organic farming. The aims of this study were (1) to investigate the effectiveness of repeated mechanical weeding of R. obtusifolius from the permanent sward, cut two or three times per year, by digging the plants out from 5 cm below the soil surface, and (2) to test the effect of nutrient availability on the effectiveness of mechanical weeding. In 2007, the manipulative experiment was established on permanent grassland infested by R. obtusifolius using the following fertilizer treatments: control, P, N, NP and NPK. Plants of R. obtusifolius were removed eight times during three vegetation seasons. No significant decrease in the density of R. obtusifolius was recorded after three vegetation seasons and density was not significantly affected by fertilizer treatment. The cover of R. obtusifolius decreased slightly, but significantly, over the study period from 7.5% to 4.5%. The cover of R. obtusifolius was only marginally affected by fertilizer treatment. Mechanical weeding by digging the plants out from 5 cm below the ground is not a sufficient method of control for R. obtusifolius in infested fertile grasslands, even when applied eight times during three vegetation seasons.

Improvement in leaf hydraulics is directly related to the improvement of plant tolerance to drought stress. Therefore, a field and pot experiment was carried out to determine the type of genetic variability and selection of parental types on the basis of combining ability for leaf hydraulics. Genotypes showed similar performance in both experiments; higher values were shown by drought tolerant genotypes in all traits except for osmotic potential, which drought tolerant genotypes maintained lower. Osmotic adjustment in pot experiment showed the highest magnitude of additive type of genetic variability. Female showed a higher and significant contribution of general combining ability effects as compared to male; it suggests that within genotypes female rather than male mostly contribute for additive genes. AMES-10103 showed the highest general combining ability effects for traits such as turgor pressure and osmotic adjustment.

A micro-plot field experiment with reduced urea ¹⁵N application was conducted to study the effects of urease inhibitor NBPT (N-(n-butyl) thiophosphoric triamide) and nitrification inhibitor DMPP(3,4-dimethyl-1H-pyrazolium dihydrogen) on the fate of applied urea ¹⁵N; it aimed to find an efficient way to reduce the urea N application rate while improving the agronomic and environmental benefits. Five treatments were installed, i.e., 180 kg N/ha (N₁, conventional application rate), 126 kg N/ha (N₂, reduced to 70% conventional application rate), N₂ + NBPT, N₂ + DMPP, and N₂ + NBPT + DMPP. Compared with treatment N₁, all the other treatments had a significantly higher total ¹⁵N recovery by both soil and plant (P < 0.05 48.20, 41.39, 37.69, 38.85 and 34.83% soil recovery for N₂ + NBPT + DMPP, N₂ + DMPP, N₂ + NBPT, N₂ and N₁treatment, respectively; and 42.68, 40.86, 40.25, 37.18 and 36.30% plant recovery for N₂ + NBPT + DMPP, N₂ + DMPP, N₂ + NBPT, N₂, and N₁ treatment, respectively). In the plant ¹⁵N recovery, the ¹⁵N absorbed in grain/stem was highest in treatment N₂ + NBPT + DMPP. The maize biomass and the maize yield had a slight increase in treatment N₂ + NBPT + DMPP, compared with those in treatment N₁. In sum, for the maize production in study area, N₂ + NBPT + DMPP application method would be a feasible way to ensure the normal maize yield while improving yield quality, saving urea fertilizer, and protecting the environment.

In order to study the characteristics of element values in the cell of plants and soils and their relationships that would help to evaluate the biogeochemical effect of soil on the element contents in the cells of plants in the same environment of Southwestern China, the soil samples were collected for analysis and the weight and atom percentage of elements (WT% and AT%) in the leaves of two different species of Flos Lonicerae were analyzed by the electron probe (EDX-9100). The results of soil analysis show that the nutrient element contents in the soil are determined by the liable content of elements, which were arranged as: Ca > Mg > Cu > Mn > K > Na > P > B > SiO₂ > Zn > Fe, even though the total element values in soil of different horizons were arranged as: SiO₂ > Fe > Ca > Mg > K > Na > Mn > P > Zn > B > Cu. It indicates that karst environment is composed of soluble calcium-rich rock and soil scarcity. Moreover, the migratory velocity and availability of elements are also determined by their coefficient variability. According to statistical results, Ca, Mn and P in the soil have high coefficient variability, reflecting its background of karst soil. Based on the electron probe, it is shown that the content of Ca is higher while Mg is the lowest in the cell of two different species of Flos Lonicerae (r = -0.156, P < 0.05) and the content of P in the cell is inferior to Ca (r = 0.868, P < 0.01). By studying the relationship of soil and the plants, it can be seen that these results are probably caused by the characteristics of local biogeochemistry. Ca is mainly absorbed by plant with the help of transpiration and accumulated in the cell, and thus becomes a predominant element in the cell. The accumulation of Ca in cell of plant will affect the absorbency and the content of other elements in the cell of Flos Lonicerae, resulting in the different contents of other elements in the Flos Lonicerae through synergistic and antagonistic action, followed by the affected quality and officinal value of the Flos Lonicerae.

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.

An evaluation of the effects of soil structural heterogeneity on maize (Zea mays L.) root system architecture was carried out on plants grown in boxes containing fine soil and clods. The clods were prepared at two levels of moisture (0.17 and 0.20 g/g) and bulk density (ranges 1.45-1.61 g/ml and 1.63-1.79 g/ml). Soil moisture directly affected the probability of clod penetration by maize roots. Primary roots inside the clods manifested morphological deformations in the form of bends. We observed a significant increase of bends per root length at lower soil moisture (P = 0.02). Root diameter and branching density increased, and lateral root length decreased considerably inside the clods. However, once emerging out of the clods and into free soil, values of all three characteristics remained low. While changes in root diameter were caused mainly by clod moisture (P < 0.05), length of lateral roots was related to bulk density (P < 0.01). Branching density was modified exclusively by an interactive effect of both factors (P < 0.05).

The influence of mechanized cutting time on the yield and quality of hops was studied for three years (2007, 2008 and 2009) in three Czech hybrid varieties Harmonie, Rubín and Agnus. The cutting term classified as 'early' was carried out at the turn of March and April. Further cutting dates were made at intervals of 7-10 days and they were classified as 'middle' and 'late' ones. Yield and contents of alpha acids were evaluated during the machine harvest. The measured data revealed no statistical relationship between term of cutting, alpha acid content and yield in any of the tested cultivars. However, during the experimental period considerable inter-annual differences were observed, especially in the yield. Average yield in the range of 2.0-2.5 t/ha in the period 2007-2008 decreased to 1.2-1.9 t/ha in 2009 due to downy mildew attack. On the basis of the obtained data it can be recommended to cut the hybrid varieties Harmonie, Rubín and Agnus in the first ten days of April, taking into account other factors such as age and the location of hop garden and current weather conditions.

Soybean cultivation in many zones of India shows occurrence of native rhizobia besides other exotically adapted strains. In the current study, 22 rhizobial isolates (recovered from 12 different soybean growing sites) and 8 reference strains were selected for biochemical and metabolic characterization. Of 22 isolates, 18 were recovered as fast growing isolates while the rest were slow growing based on bromothymol blue (BTB) test. Unlike earlier belief that rhizobia have no ability to grow on glucose peptone agar medium, in this study, some isolates and some reference strains grew well on this medium. Similarly, when all the isolates were subjected to ketolactose test, some of the isolates were found to show growth on the medium. In contrast, based on C-utilization pattern (15 carbohydrates) a remarkable metabolic diversity was observed among the rhizobial isolates recovered in the study. The clustering and matching analysis showed that most of isolates were matching with slow growing reference strains, a few were with fast growing reference strains and some were found to be unique and hence not matching with any of reference strains. Such analysis suggests the occurrence of metabolically distinct types of rhizobia besides commonly known types (B. japonicum, B. elkanii and S. fredii) of soybean rhizobia and further validation is suggested through 16SrRNA gene sequencing technique.

The primary objective of this paper is to study the interspecific variation of ¹⁵N natural abundance in two dominant conifer tree species, Scot pine (Pinus sylvestris L.) and Norway spruce (Picea abies L. Karst) in a N-limited mixed boreal coniferous forest in southern Finland. Both a mature tree stand (a natural forest stand) and a stand of seedlings in a clear-cut area were considered. We analyzed %N and δ15N natural abundance in needles, branches, litter and soil of the both above-mentioned stands. Pine needles had higher N concentrations than spruce needles, both in mature forest (pine = 1.09%, SE ± 0.02 and spruce = 0.79%, SE ± 0.02) and in the clear-cut area (pine = 1.01%, SE ± 0.07 and spruce = 0.74%, SE ± 0.04). Furthermore, pine needles were significantly more depleted in δ15N natural abundance than the spruce needles, both in the mature forest (pine = -5.6‰, SE ± 0.1‰ and spruce = -4.0‰, SE ± 0.2‰) and in the clear-cut sites (pine = -2.8‰, SE ± 0.2‰ and spruce = -2.1‰, SE ± 0.3‰). The more pronounced depletion of ¹⁵N in the pine foliage might be connected to its different fungal associates in the roots compared to spruce roots. We assume that the mycorrhizal N-uptake is very prominent at the N-limited site. After clear-cutting, needles of the seedlings and the uppermost part of soil organic layer were found to be more 15N-enriched than at the natural forest site. This was attributed to an increased level of nitrification in the clear-cut site soil.

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.

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.

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.

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.

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.

Sulfur (S) regarded as the fourth key element is mainly taken by the plant roots. However, some plants can also absorb atmospheric sulfides, which may be of great importance for ameliorating the environment and for farming as a green organic S fertilizer used to balance insufficient soil S content for intensive cultivation in China; H₂S and mainly SO₂ are emitted to air as a result of the rapid industrialized and economic development. Globe amaranth (Gomphrena globosa L.) might be one of the plants that can use atmospheric sulfides for its growth. Therefore the effects of sulfate deprivation from root on its growth, S status and other elements concentration under hydroponic culture were explored firstly. Based on measurements of plant growth, biomass, nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), S, iron (Fe), manganese (Mn), copper (Cu), zinc (Zn), boron (B), and molybdenum (Mo) concentration, the results showed that S concentration in flower, shoot and root of plant without root sulfate supplied was increased with plant growth and development, symptoms of S deficiency disappeared and other elements concentration in plant tended to be nearly the same as the root sulfate-supplied plants. The interesting results might imply that globe amaranth may be able to live on the atmospheric sulfides as sulfur source.

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.

During the years 2006 and 2007 the phytoextraction ability of maize (Zea mays), willow-tree (Salix smithiana) and poplar (Populus nigra × P. maximowiczii) to accumulate cadmium, copper, mercury and zinc was investigated. Small scale field experiment was carried out on soil contaminated with chemicals from the waste incineration plant in Hradec Kralové (Czech Republic). Screening of this allotment showed very different contamination of all observed risk elements on places where the material intended to be burnt without safety of leakage into soil. Grown plants showed the different accumulation of observed elements in plant tissues as well as the influence of total content of the risk elements in soil. The highest Cd (1.5-1.73 mg/kg) and Zn (242-268 mg/kg) concentrations were found in willow-tree biomass mainly in the leaves. Cu and Hg were mostly accumulated by maize roots (14.6-15.8 mg Cu/kg and 1.3-7.4 mg Hg/kg) and lower amount was found out in willow-tree leaves again. In reference to total production of each plant the maximum Cd and Zn uptake by aboveground biomass was found in poplars (201 mg Cd/m² and 38 200 mg Zn/m²) and maize, which showed high Zn uptake. The biggest amount of copper (2563 mg Cu/m²) was accumulated by aboveground maize biomass on the collection point with the highest Cu concentration in soil and by poplar (2394 mg Cu/m²) on the other collection point. The highest Hg uptake differs in reference to total Hg content in soil; willow-tree has the highest uptake on the place with lower Hg content in soil (44.6 mg Hg/m²) and maize has the highest uptake on the place with higher Hg content in soil (92 mg Hg/m²).

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.