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The objective of this work was to evaluate the effect of tractor wheeling with a light tractor on the root growth and soil properties of smooth brome in South Estonia. Field experiment was conducted on sandy loam Haplic Luvisol in 2007. Data were collected during September 2008 in both an uncompacted and compacted area. Because of the compaction, the precompression stress increased in the upper soil layer (0-10 cm) by 12.6% and 15.2% at a depth of 10-20 cm. Compaction had only a minor effect on the bulk density, values increased 4.7% in the upper soil layer and 1.8% in the deeper layer. Differences in the saturated hydraulic conductivity (k_s) were not significant; however, the decrease in the k_s was 26.6% in the upper level and 12.5% in the deeper (10-20 cm) layer. At a depth of 0 to 30 cm compaction decreased the root length by 44.7% and the root mass by 60.5% compared with the uncompacted soil. Altogether, this study confirms the unfavourable effect of wheeling on grasslands even when the wheeling is performed with a light tractor on dry soil.

The aim of this work was to compare herbicide efficacy and reduction of weed reproduction after the application of three frequently used soil residual herbicides during pre-emergent (PRE) and early post-emergent (EPOST) application in maize. Plot field trials were carried out in Central Bohemia during two growing seasons (2010 and 2011). Good efficacy (88%, resp. 83%) was found in isoxaflutole + thiencarbazone (ISF + THC) and terbuthylazin + S-metolachlor (TBA + SMC) on Echinochloa crus-galli, especially in PRE application use. Efficacy on Amaranthus retroflexus was 91% at both tested application periods and there were no significant differences between experimental years. Significant differences in A. retroflexus control were recorded among all tested herbicides (ISF + THC > TBA + SMC > pendimethalin (PEM) + dimethenamid (DMA)). No significant differences between PRE and EPOST were recorded in efficacy on Chenopodium album. Significant differences in efficacy on C. album were recorded among all tested herbicides (ISF + THC > TBA + SMC > PEM + DMA). Mercurialis annua was the most tolerant tested weed, which was significantly better controlled at EPOST herbicide application (73%) compared to PRE application (32%). TBA + SMC showed a significantly higher efficacy on M. annua compared with other tested herbicides. Seed production of all tested weeds was strongly effected by weather conditions, which were significant during 2011, when there was higher than average precipitation during May and June. The most seeds were produced by A. retroflexus > C. album > E. crus-galli > M. annua. ISF + THC best reduced seed production of E. crus-galli, A. retroflexus and C. album, especially when applied at PRE. TBA + SMC best reduced seed production of M. annua. Weed competition on untreated control plots caused yield loss by 90%and 47% in 2011 and 2012, respectively, compared to treatments with the highest yield (ISF + THC).

The study should reveal the effects of soil texture and of seed characteristics of oilseed rape (Brassica napus L.) on seed survival in the soil by a burial experiment. Seeds of 58 conventional and new trait accessions (genetically modified and/or with altered seed ingredients) were buried for six months in sandy loam (SL), clay (c) or silty clay loam (SICL) in the seasons 2008/2009 and 2009/2010 in Germany. Between 84-93% (2008/2009) and 64-87% (2009/2010) of the conventional seeds survived in the soil, and so did 41-67% and 8-44% of the new trait seeds. Significantly more seeds were found in C and SICL compared to SL. Seed survival also significantly depended on the genotype, with high and low seed survival in both conventional and new trait accessions. Seed survival rates are probably linked with moisture and oxygen provided by different soils. As soils with good water storage conditions seem to have a higher probability for oilseed rape seeds from harvest losses to survive, other measures such as growing low dormancy varieties and proper soil tillage are especially relevant to avoid volunteers on these soils.

Chicory (Cichorium intybus L.) is a rich source of polysaccharides (intibin and inulin), vitamins, acids and mineral salts. The present studies determined the antagonistic activity of selected bacteria of the soil environment of root chicory towards fungi pathogenic towards this plant: Alternaria alternata, Botrytis cinerea, Fusarium culmorum, F. oxysporum, Thanatephorus cucumeris and Sclerotinia sclerotiorum. Root chicory was cultivated with using cover crops (oats, tansy phacelia and common vetch). The use of cover crops, especially oats, in the cultivation of root chicory had a positive effect both on the total population of bacteria and the population of Bacillus spp. and Pseudomonas spp. in the soil. Antagonistic Bacillus spp. and Pseudomonas spp. displayed differentiated activity towards the studied fungi. The greatest antagonistic effect was found out after the mulch of oats. After common vetch, the antagonistic activity of bacteria was more than twice, and after phacelia three times as low as after oats. In the traditional cultivation of root chicory this activity was nearly twelve times lower.

Machines without satellite navigation in fields have a tendency to pass-to-pass errors, especially unwanted overlaps, resulting in waste of fuel and pesticides, longer working times and also environmental damage. This paper evaluates the accuracy of individual machinery passes in fields. Real pass-to-pass errors (omissions and overlaps) in a field were measured on different tractor-implement units with and without guidance system utilization and a comparison between observed guidance arrangements was made regarding final working accuracy and possible benefits from navigation utilization. Additionally, intensity of machinery passes, and repeated passes on soil, as a possible risk for soil compaction in fields, were monitored. The outcomes from our measurements revealed a statistically significant difference between the total area treated by machinery without any guidance system and machinery using precise guidance systems. Concerning the intensity of traffic in fields, it was found out that more than 86% of the total field area was run-over at least once during one cropping season when using conventional tillage practice. The usage of guidance systems can reduce machinery traffic in field to some extent as well and thus improve soil conditions.

Seeds are the primary sinks for photosynthates during reproductive growth. Variation in light intercepted during and after seed initiation has been found a major environmental determinant of soybean [Glycine max(L.) Merrill] seed size. We investigated the influence of light enrichment and shading on seed growth rate, effective filling, cotyledon cell number, cell volume and endogenousABA concentrations of cotyledons/testas during seed filling of soybean. Evans, an indeterminate Group 0 soybean, was subjected to light reduction and enrichment treatments from the beginning of pod formation until final harvest for two years inMassachusetts. Higher rates of seed growth, greater seed dry weight, and higher cotyledon cell number were all observed with light enrichment. There was a reduction in seed growth rate and cotyledon cell number, along with a significant lowering of endogenousABA levels in testa and cotyledon with shade. The level ofABAin cotyledon during seed development was significantly correlated with seed growth rates only under shade treatments. Both the growth rates and seed filling duration were influenced by variation in light interception by the soybean canopy. The effects of varying light treatment on seed size, within one genotype, were most likely due to the differences in seed growth rate and cotyledon cell number.

Wheat grain products are the primary source of dietary Cd-intake for humans. Since varieties differ markedly in grain-Cd accumulation, efforts are needed to find traits associated with low, or high, accumulation. Two durum wheat varieties, selected in a field screening as low (Creso) and high (Svevo) grain-Cd accumulating, were grown on soil spiked with 1.5, 3 and 4.5 mg Cd/kg. Growth patterns, Cd uptake and translocation were investigated at heading and maturity. Cadmium did not affect plant growth and grain yield, but grain-Cd concentration always exceeded the permissible limit of 0.2 mg Cd/kg, and was approximately double in Svevo than in Creso. At maturity, total Cd-uptake increased linearly with supply in Creso, from 13 to 23 µg/plant, and was approximately 18 µg/plant, irrespective of Cd level, in Svevo. Partitioning to shoot was higher in Svevo than in Creso, both at heading and maturity. We suggest that reduced plant height, high root to shoot biomass ratio during vegetative growth and elevated post-heading dry matter accumulation promoted Cd accumulation into grain. Since these traits are common to modern wheat varieties, risks of grain Cd-contamination can increase in the future.

The aim of this study was to investigate the impact of used technology and environmental condition on lucerne dry matter yield in the regional conditions. During a three year period (2011-2013), the investigation was based on management survey in 27 farms in the Czech Republic. Climate conditions significantly influenced yield in some interaction with soil where only combination of dry climate and less fertile soil conditions reduced forage yield. The single soil effect was not significant for forage yield. Applied technology was influenced by both environment and farm characteristic (such as farm size and cow's milk performance) which together significantly explained about 40% of variability of used technological properties. From all investigated technological properties, only cultivation of lucerne in mixture with grasses consistently increased forage yield therefore should be considered as important factor for modelling forage farm yield in the regional conditions.

The purpose of the studies was to establish the quantitative composition of bacteria Bacillus spp. and Pseudomonas spp. and their antagonistic effect towards soil-borne fungi after the cultivation of oats, spring vetch and tansy phacelia as intercrop cover plants. The total population of bacteria in 1 g dry weight of the soil from the experimental combination where mulch of oats was used was larger than in the combination with spring vetch or tansy phacelia. Totally, approximately three times as much Bacillus spp. was obtained from soil samples as compared to Pseudomonas spp. Tests showed that the most isolates of antagonistic bacteria out of the enumerated genera occurred in the soil after oats cultivation, and the least in the soil after the cultivation of tansy phacelia. Antagonistic Bacillus spp. and Pseudomonas spp. inhibited the growth and development of Fusarium oxysporum, Haematonectria haematococca and Thanatephorus cucumeris in the most effective way. The greatest total antagonistic effect of Bacillus spp. and Pseudomonas spp. towards Altenaria alternata, F. culmorum, F. oxysporum, H. haematococca, P. irregulare and T. cucumeris was found out after managing the mulch of oats. The smallest total antagonistic effect of bacteria was observed after managing the mulch of tansy phacelia.

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.

The article presents the possibilities of visual and statistical outputs from the telemetric tracking of game: activity data, heat map, home regions, movement routes and the points of occurrence. Nowadays the methods of the telemetric tracking of game are also used for finding the best ways to eliminate damage caused by wild boar generally, and field crops damage specifically. From telemetrically gained data it is possible to study the local habits of wild boar and their preference of crops and cultivars in various periods. On the basis of this knowledge it is possible to implement the necessary agrotechnical measures. The pilot processing and verification is run on the portal Zvěř (game) online (http://zver.agris.cz/). Currently there are 11 wild boars marked and tracked. The public part of portal is used for the basic presentation of data; in the non-public part the data of private subjects (agricultural companies and hunting organizations) that are not interested in public presentation are processed in the same way. In this way there is at disposal an integral system of wild boar tracking: capturing, marking, data collection, processing and presentation. This system can be used by research institutions, farmers and hunters.

Citrus plants often suffer from temperature stress, which seriously inhibits tree growth and even results in tree death. The present experiment was conducted to evaluate the effects of Glomus mosseae on growth, root morphology, superoxide dismutase (SOD) and catalase (CAT) activities, and soluble protein content of trifoliate orange (Poncirus trifoliata) seedlings at low (15°C), optimum (25°C) and high (35°C) temperatures. Sixty-eight days after temperature stresses, mycorrhizal colonization and number of both entry points and vesicles were significantly inhibited by low or high temperature. Mycorrhizal seedlings recorded significantly higher growth characteristics than non-mycorrhizal seedlings at both optimum and high temperatures, but the beneficial effects were almost lost at low temperature. Generally, mycorrhizal seedlings presented notably higher root traits (projected area, surface area, number of forks and volume) than non-mycorrhizal seedlings regardless of temperature levels. Mycorrhizal colonization significantly increased SOD and CAT activities and soluble protein content at high temperature, increased only SOD activity at optimum temperature, and decreased only soluble protein content at low temperature. It suggests that mycorrhizal alleviation of temperature stress in trifoliate orange seedlings was at high temperature, but the alleviation was obviously weakened at low temperature.

Low availability of phosphorus (P) in soil is a major constraint for crop production in agricultural ecosystems. Therefore, it is very important to explain the adaptive mechanism of crops under low P conditions. The response of high- and low-P efficient soybean (Glycine max L.) genotypes to various external P level was carried out in nutrient solution culture. Results showed that Dongnong1031 (low P-efficient genotype) undergoes major changes in terms of dry mass, root length, root number and root surface, while these response of Hai 616 (high P-efficient genotype) was lower after five weeks of growth. The higher P level in solution, the smaller difference between the two genotypes in these parameters. The amount of H+ released by root of Dongnong1031 was lower than that of Hai 616, except when supplied with 50 μmol external P. There was a positive relationship between RPAE (relative phosphorus absorption efficiency) and P concentration in shoot and root material at all P levels, irrespective of soybean genotype. An exponential relationship was found between PUE (phosphorus utilization efficiency) and P concentrations in shoots and roots. These results suggested that an increase in measured root parameters coupled with H+ release by roots were key mechanisms for soybean genotypes with high-P efficiency to cope with low P conditions when grown in solution. In order to best select high soybean genotype with high-P efficiency one should pay attention to PUE combined with high RPAE.

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.

Both earthworms and symbiotic arbuscular mycorrhizal fungi (AMF) often co-occurr in ecosystems, however very little is known on their interrelationships. Here we tested to what extent earthworms (Annelida) or AMF (Glomales) separately or in combination affect the growth of the pharmaceutical plant species, pot marigold (Calendula officinalis, Asteraceae). We conducted a greenhouse experiment using non-sterilized field soil where we manipulated the factors earthworms (addition/no addition of the vertical burrowing species Lumbricus terrestris) and AMF (addition/no addition of a mix of the four Glomus taxa G. geosporum, G. mosseae, G. intraradices, G. claroideum). Leaf length and flower stem length was significantly increased by earthworms but remained unaffected by additional AMF. The longest leaves and flower stems were observed in pots containing earthworms but no additional AMF. The number of flower buds was unaffected by earthworms but marginally significantly increased by AMF. Plant shoot biomass production was significantly higher when earthworms were present; AMF inoculation had no effect on biomass production. Root biomass production and total plant biomass production remained unaffected by earthworms or AMF. These results indicate that in soil already containing AMF earthworm addition primarily affects vegetative growth while additional AMF inoculation tended to affect reproductive plant parts.

The root system of plants is generally regarded as a factor, which is in relation to important agronomic and ecological characteristics. The aim of this study was to investigate the effect of high initial stand density on the reduction in development of lucerne root morphology traits and how long-term this effect would be. In spring 2003, a field experiment with six lucerne entries in randomized blocks was established. Broadcast sowing was used and the seeding rate was 5000 germinated seeds per m2. In 2003-2009, the plants were sampled in each plot in autumn; the average depth of sampling was 0.2 m. The stand density reached an average value of 860 plants per m2 in the autumn of the seeding year and this strongly reduced the root weight, tap-root diameter, position and number of lateral roots. The subsequent decrease of stand density to 57 plants/m2 in 2009 was not linear but it was extremely quick from the 1st to 2nd year and, by contrast, it was extremely slow in the last three years. It indicates that older plants with larger tap-root diameter probably have a higher persistency. All evaluated root traits were developed slowly, nevertheless, they reached common values during a seven year period. The intensity of the relation of stand density to root weight or tap-root diameter increased over time whilst it decreased to the ratio of root-branched plants. Results suggest that an assessment of density in samples should be recommended for the varieties evaluation in case of irregularly-spaced plants because the differences in root morphology among varieties could be caused by the differences in density among the varieties. It is possible to conclude that lucerne stands under higher initial density provided a strongly reduced speed of root development with an impact on important agronomic traits connected with root morphology.

The effects of lead on root, shoot and seedling length, leaf area, number of leaves, plant circumference, seedling dry weight, root/shoot and leaf area ratios of Thespesia populnea L. were determined in greenhouse under natural environmental conditions with and without phytotoxic metal ions at 5, 10, 15, 20, and 25 µmol/l. Lead treatments have a strong influence on the growth and development of T. populnea by reducing significantly (P < 0.05) all the above parameters. Lead treatment at 5-25 µmol/l produced significant (P < 0.05) effects on seedling and root length, plant circumference and seedling dry weight of T. populnea, while lead treatment at 10-25 µmol/l produced significant (P < 0.05) effects on shoot length, number of leaves and leaf area as compared to control. Tolerance in T. populnea seedling at 25 µmol/l of lead treatment was lowest as compared to all other treatments.

To understand the mechanisms causing yield limitations in defoliated plants subjected to water deficiency, the experiments were laid out as a randomized complete block design with split-plot arrangement. Soil-water regimes consisted of moderate irrigation until physiological maturity (W₁) or short severe water stress periods (W₂) at V₈ stage of ontogenesis, and tasseling which allotted to the main plots. Defoliation times (V₈ and tasseling) and intensities (cutting of one or two thirds of leaf blade) combinations and one control level (five Source restriction treatments) were allotted to subplots. Early defoliation caused reduction in grain yield at W₁ and W₂ by 19.2 and 14.8%, respectively. On the other hand, water deficiency reduced grain per ear by 23.9% and increased individual grain weight by 37.0% (plasticity of sink capacity). These results show that under water deficiency, grain yield limitation was mostly due to a reduction in dry matter allocation to grains (sink capacity) than a result of lower dry matter production (source strength). Findings suggest that in non-irrigated corn, breeders must direct their selection program to increase grain set and decrease surplus leaves.

The effects of land use practices on soil fauna, especially earthworms, are poorly known in coastal saline agricultural soils. Here we compare earthworm communities in six types of land use practice in the coastal region of China's Bohai Bay, namely uncultivated saline soil, two orchard (pear and winter jujube) lands, man-made forests (chinese ash), vegetable land and cropped land (maize). In addition, we recorded selected physicochemical properties of the soil. Soil organic matter content and total N were significantly higher under pear orchard and vegetable land than under the other land use practices, and their lowest values were observed from uncultivated saline soil. Vegetable land and pear orchard land showed a significantly higher abundance of earthworms than the other land use practices, whereas no earthworm was found in uncultivated saline soil. The sites under individual practices supported one to three earthworm species. Aporrectodea trapezoides species was present under four types of land use practice, and the biomass of this species accounted for more than 60% of the community. Vegetable land and pear orchard land supported richer earthworm community than the other land use practices, dominated by Aporrectodea trapezoides and Drawida japonica. These preliminary results indicated that land use practices have substantial effects on the abundance and composition of earthworm communities in saline soils.

One of the factors frequently affecting yields is topography. Topographic data can be obtained from various sources with different precision. This work evaluates suitability of airborne laser scanning data for use as another source of topographical characteristics creation in a smaller scale in regards to precision agriculture needs. Simple models of elevation, slope and flow accumulation were created and the correlation between yield and topography was determined over a seven-year period in relation to precipitations and temperature. The suitability of airborne laser scanning data was proved with certain limitations. Flow accumulation model derived from original airborne laser scanning data indicated the right trend of flow accumulation but not as clearly compared to other models. In drier years the correlation coefficients between flow accumulation and yield reached up to 60-70%.

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.

The objectives of present study were to determine the residual and cumulative effects of zinc (Zn) fertilizer on cotton (Gossypium hirsutum L.) and wheat (Triticum aestivum L.) in a silt loam Typic Haplocambid soil (< 0.05 mg/kg diethylenetriaminepentaacetic acid (DTPA)-Zn). The study comprised of two years field experiments where first cotton crop received zinc sulphate (ZnSO₄∙H₂O) at five rates (0, 5, 7.5, 10, 12.5 kg Zn/ha) in a randomized complete block design with four replications. After harvest, each plot was divided into two sub-plots. To study the residual effect, one sub-plot of all plots did not receive Zn fertilizer for the subsequent crops; however, the other sub-plot received all Zn rates for 2005-06 wheat, 2006 cotton, and 2006-07 wheat. Fresh applied, residual as well as cumulative Zn application significantly (P ≤ 0.05) increased crops production for both experimental years. Residual effect of 5.0 kg Zn/ha optimized the 2006 cotton yield; however, wheat productivity was optimized with residual effect of 7.5 kg Zn/ha in 2005-06 and of 10.0 kg Zn/ha in 2006-07. Optimum yield of both crops was attained with a lesser fresh-applied and residual Zn rate than cumulative Zn rate. Total Zn uptake by wheat (134.9-289.6 g/ha) was much greater than by cotton (92.3-192.5 g/ha). It is concluded that one application of 7.5 kg Zn/ha proved adequate for optimizing two cycles of the cotton-wheat production system. Two-year repeated use of 5.0-7.5 kg Zn/ha did not depress crop yields.

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.

Little attention has been paid to the effect of long-term fertilizer application on concentrations of elements in grain of barley produced on the metal non-contaminated agricultural soil. In 2010, we analyzed yield and concentrations of elements in grain of spring barley in unfertilized control, mineral fertilizer application (N₄P₂K₂ - 70, 60 and100 kg N, P and K per ha) and combinations of farmyard manure or poultry litter with mineral fertilizer (FMN₄P₂K₂ and PLN₄P₂K₂) treatments in the Ruzyně Fertilizer Experiment established on Luvisol in 1955 in Prague (Czech Republic). The yield of grain ranged from 4.03 to 9.74 t/ha in the control and FMN₄P₂K₂ treatment. There was a positive effect of fertilizer application on concentrations of nitrogen, phosphorusand potassium, but no effect on concentrations of calcium and magnesium. With the exception of iron, concentrations of micro (copper and zinc) and risk elements (arsenic, cadmium, chromium, lead, manganese and nickel) were not significantly affected by the fertilizer treatments. Long-term use of organic and mineral fertilizers with appropriate application rates does not represent any risk for contamination of barley grain by risk elements on mineral rich and metal non-contaminated agricultural soils.

To investigate the effect of low soil pH caused by fertilization on soil available zinc in calcareous soil, this study was conducted based on a long-term experiment consisting of: (a) no fertilization (CT); (b) mineral fertilizer application coupled with 7500 kg/ha of wheat straw (WS-NPK); (c) mineral fertilizer application coupled with 3750 kg/ha of wheat straw (1/2WS-NPK); (d) mineral fertilizer application alone (NPK). Long-term fertilization results in a significant increase in soil DTPA-extractable zinc. However, the increased soil DTPA-extractable zinc is unavailable to crops and mainly confined to 0.25 mm > and 0.25 mm to 1 mm aggregates. Compared to CT, soil DTPA-extractable zinc under fertilization is more than 9.67% and 122.36% higher in 0.25 mm > and 0.25 mm to 1 mm aggregates, respectively. Furthermore, plant-available zinc in the 0-15 cm soil layer and wheat grain zinc are both significantly positive related to soil DTPA-extractable zinc in > 2 mm aggregates. Therefore, plant-available zinc in the 0-15 cm layer is closely associated with DTPA-extractable zinc in > 2 mm aggregates, and the low soil pH caused by long-term fertilization could not enhance plant-available zinc in the surface soil layer nor elevate wheat grain zinc concentration because of the occlusive effect of soil aggregates.

The tolerance, accumulation and subcellular distribution characteristics of cadmium (Cd) in ramie (Boehmeria nivea L. Gaud.) were investigated using a 2-year field experiment. The results indicated that ramie has a certain extent of tolerance to soil Cd (≤ 20 mg/kg) contamination with no significant decrease in shoot biomass and fibre yield relative to control conditions. Although ramie did not hyperaccumulate Cd, it accumulated considerable amount of Cd in the aboveground parts (approximately 0.19 to 1.09 kg/ha annually). The Cd contents retained in ramie tissues were found in order of roots > stems > leaves. Further, regarding the subcellular distribution of Cd in ramie tissues, 80% of the total Cd was bound to the cell walls of the roots and stems, whereas in leaves the proportion of Cd stored in the cell wall fraction was around 60% and a lesser amount of Cd was stored in the soluble fraction (24.1-25.5%). Our collective results indicated that ramie adapts to Cd stress via the store of a large amount of Cd in cell walls, and suggested potential usefulness of ramie in the phytoremediation of Cd-contaminated farmlands.

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.

A field study was conducted to ascertain the effect of three zinc (Zn) levels: 0, 20 kg ZnSO₄/ha and 20 kg ZnSO₄/ha + foliar spray of 0.5% ZnSO₄, on wheat grain Zn content and factors contributing to or hindering in its bioavailability. Increasing Zn levels were established as serviceable in improving the nutritional status of genotypes. Soil application + foliar spray proved to be paramount for all the traits leading to an 80% increase in grain Zn content, 61.3% in methionine content and a decrease of 23.2% in phytic acid as an average of all genotypes and both years. The genotype UP 2382 was found more suited to Zn fertilization in allocating Zn and maintaining a lower phytate to Zn molar ratio.

The research results have shown that the enzyme pH index (0.49-0.83) confirmed the neutral or alkaline nature of the soils. Neither the changes in the content of available phosphorus nor in the activity of dehydrogenases, catalase, alkaline and acid phosphatase in soil were due to the factors triggering soil salinity; they were a result of the naturally high content of carbon of organic compounds, which was statistically verified with the analysis of correlation between the parameters. There were recorded highly significant values of the coefficients of correlation between the content of available phosphorus in soil and the activity of alkaline (r = 0.96; P < 0.05) and acid phosphatase (r = 0.91; P < 0.05) as well as dehydrogenase (r = 0.90; P < 0.05). To sum up, one can state that Mollic Gleysols in Inowrocław are the soils undergoing seasonal salinity; however, a high content of ions responsible for salinity is balanced with a high content of organic carbon, humus, phosphorus and calcium directly affecting the fertility of the soils analyzed. The activity of the enzymes depended on the natural content of carbon of organic compounds and not on the factors affecting the soil salinity, which points to the potential of such tests for soil environment monitoring.