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We screened 20 different clones of willow and poplar species in hydroponic experiments for their metal resistance and accumulation properties. Plants were exposed for 4 weeks either to single additions of (microM) 4.45 Cd or 76.5 Zn, or a metal cocktail containing the same amounts of Cd and Zn along with 7.87 Cu and 24.1 Pb. Plant biomass, metal tolerance and metal accumulation pattern in roots and leaves varied greatly between clones. The leaf:root ratio of metal concentrations was clearly underestimated compared to soil experiments. The largest metal concentrations in leaves were detected in Salix dasyclados (315 mg Cdkg(-1) d.m.) and a Salix smithiana clone (3180 mg Znkg(-1) d.m.) but these species showed low metal tolerance. In spite of smaller Cd and Zn concentrations, the metal-tolerant clones Salix matsudana, Salix fragilis-1, and Salix purpurea-1 hold promise for phytoextraction as they produced large biomass and metal contents in leaves.

We screened 20 different clones of willow and poplar species in hydroponic experiments for their metal resistance and accumulation properties. Plants were exposed for 4 weeks either to single additions of (microM) 4.45 Cd or 76.5 Zn, or a metal cocktail containing the same amounts of Cd and Zn along with 7.87 Cu and 24.1 Pb. Plant biomass, metal tolerance and metal accumulation pattern in roots and leaves varied greatly between clones. The leaf:root ratio of metal concentrations was clearly underestimated compared to soil experiments. The largest metal concentrations in leaves were detected in Salix dasyclados (315 mg Cdkg(-1) d.m.) and a Salix smithiana clone (3180 mg Znkg(-1) d.m.) but these species showed low metal tolerance. In spite of smaller Cd and Zn concentrations, the metal-tolerant clones Salix matsudana, Salix fragilis-1, and Salix purpurea-1 hold promise for phytoextraction as they produced large biomass and metal contents in leaves.

An experiment was conducted under laboratory conditions to investigate the effect of increasing concentrations of fenitrothion (2, 10 and 200 mg a.i./kg soil), diuron (1.5, 7.5 and 150 mg a.i./kg soil) and thiram (3.5, 17.5 and 350 mg a.i./kg soil) on soil respiration, bacterial counts and changes in culturable fraction of soil bacteria. To ascertain these changes, the community structure, bacterial biodiversity and process of colony formation, based on the r/K strategy concept, EP- and CD-indices and the FOR model, respectively, were determined. The results showed that the measured parameters were generally unaffected by the lowest dosages of pesticides, corresponding to the recommended field rates. The highest dosages of fenitrothion and thiram suppressed the peak SIR by 15-70% and 20-80%, respectively, while diuron increased respiration rate by 17-25% during the 28-day experiment. Also, the total numbers of bacteria increased in pesticide-treated soils. However, the reverse effect on day 1 and, in addition, in case of the highest dosages of insecticide on days 14 and 28, was observed. Analysis of the community structure revealed that in all soil treatments bacterial communities were generally dominated by K-strategists. Moreover, differences in the distribution of individual bacteria classes and the gradual domination of bacteria populations belonging to r-strategists during the experiment, as compared to control, was observed. However, on day 1, at the highest pesticide dosages, fast growing bacteria constituted only 1-10% of the total colonies number during 48 h of plate incubation, whereas in remaining samples they reached from 20 to 40% of total cfu. This effect, in case of fenitrothion, lasted till the end of the experiment. At the highest dosages of fenitrothion, diuron and at all dosages of thiram the decrease of biodiversity, as indicated by EP- and CD-indices on day 1, was found. At the next sampling time, no significant retarding or stimulating effect was detected. However, in case of CD values the higher differences were observed. The significant impact of pesticides on the physiological state of soil bacteria was not found. They were generally in dormant state (lambda < 0.5), but immediately after pesticides application, the additional reduction of frequency of bacterial cell proliferation (max. decrease of lambda value to 0.15 for thiram on day 14) and prolonged retardation time of colony appearance (max. increase of t(r) value to 1.39 for fenitrothion on day 1) on agar plates were found.

An experiment was conducted under laboratory conditions to investigate the effect of increasing concentrations of fenitrothion (2, 10 and 200 mg a.i./kg soil), diuron (1.5, 7.5 and 150 mg a.i./kg soil) and thiram (3.5, 17.5 and 350 mg a.i./kg soil) on soil respiration, bacterial counts and changes in culturable fraction of soil bacteria. To ascertain these changes, the community structure, bacterial biodiversity and process of colony formation, based on the r/K strategy concept, EP- and CD-indices and the FOR model, respectively, were determined. The results showed that the measured parameters were generally unaffected by the lowest dosages of pesticides, corresponding to the recommended field rates. The highest dosages of fenitrothion and thiram suppressed the peak SIR by 15-70% and 20-80%, respectively, while diuron increased respiration rate by 17-25% during the 28-day experiment. Also, the total numbers of bacteria increased in pesticide-treated soils. However, the reverse effect on day 1 and, in addition, in case of the highest dosages of insecticide on days 14 and 28, was observed. Analysis of the community structure revealed that in all soil treatments bacterial communities were generally dominated by K-strategists. Moreover, differences in the distribution of individual bacteria classes and the gradual domination of bacteria populations belonging to r-strategists during the experiment, as compared to control, was observed. However, on day 1, at the highest pesticide dosages, fast growing bacteria constituted only 1-10% of the total colonies number during 48 h of plate incubation, whereas in remaining samples they reached from 20 to 40% of total cfu. This effect, in case of fenitrothion, lasted till the end of the experiment. At the highest dosages of fenitrothion, diuron and at all dosages of thiram the decrease of biodiversity, as indicated by EP- and CD-indices on day 1, was found. At the next sampling time, no significant retarding or stimulating effect was detected. However, in case of CD values the higher differences were observed. The significant impact of pesticides on the physiological state of soil bacteria was not found. They were generally in dormant state (lambda < 0.5), but immediately after pesticides application, the additional reduction of frequency of bacterial cell proliferation (max. decrease of lambda value to 0.15 for thiram on day 14) and prolonged retardation time of colony appearance (max. increase of t(r) value to 1.39 for fenitrothion on day 1) on agar plates were found.

A technological solution was developed to process slaughter waste and farm manure and transform them into organic and mineral fertilizers. It has been shown that the formation of an enclosure on a goose farm from nitrogen-binding substances (brown coal, a mixture of brown coal with magnesite, used ash substrate) has a positive effect on reducing nitrogen emissions, even to about 80%. The presented solution is in line with ecological trends and ensures comprehensive management of agri-food waste. It reduces the loss of valuable nutrients from renewable sources, increases the efficiency of fertilizers and reduces the environmental nuisance of poultry farms. Organic-mineral fertilizers made from slaughterhouse waste and poultry manure were as effective as expensive commercial mineral fertilizers. New fertilizers helped to obtain a yield similar to the groups fertilized with mineral fertilizers: 11 t per ha for maize (grain), 0.8 t per ha for mustard (seed), 10 kg per 1 m2 of radish (all), and 18.5 kg per 1 m2 of beet (whole) while reducing production costs thanks to the use of waste materials.

A technological solution was developed to process slaughter waste and farm manure and transform them into organic and mineral fertilizers. It has been shown that the formation of an enclosure on a goose farm from nitrogen-binding substances (brown coal, a mixture of brown coal with magnesite, used ash substrate) has a positive effect on reducing nitrogen emissions, even to about 80%. The presented solution is in line with ecological trends and ensures comprehensive management of agri-food waste. It reduces the loss of valuable nutrients from renewable sources, increases the efficiency of fertilizers and reduces the environmental nuisance of poultry farms. Organic-mineral fertilizers made from slaughterhouse waste and poultry manure were as effective as expensive commercial mineral fertilizers. New fertilizers helped to obtain a yield similar to the groups fertilized with mineral fertilizers: 11 t per ha for maize (grain), 0.8 t per ha for mustard (seed), 10 kg per 1 m2 of radish (all), and 18.5 kg per 1 m2 of beet (whole) while reducing production costs thanks to the use of waste materials.

The establishment of phytoextraction crops on highly contaminated soils can be limited by metal toxicity. A recent proposal has suggested establishing support crops during the critical initial phase by metal immobilization through soil amendments followed by subsequent mobilization using elemental sulphur to enhance phytoextraction efficiency. This 'combined phytoremediation' approach is tested for the first time in a pot experiment with a highly contaminated soil. During a 14-week period, relatively metal-tolerant maize was grown in a greenhouse under immobilization (before sulphur (S) application) and mobilization (after S application) conditions with soil containing Cd, Pb and Zn contaminants. Apart from the control (C) sample, the soil was amended with activated carbon (AC), lignite (Lig) or vermicompost (VC) all in two different doses (dose 1~45 g additive kg-1 soil and dose 2~90 g additive kg-1 soil). Elemental S was added as a mobilization agent in these samples after 9 weeks. Biomass production, nutrient and metal bioavailability in the soil were determined, along with their uptake by plants and the resulting remediation factors. Before S application, Cd and Zn mobility was reduced in all the AC, Lig and VC treatments, while Pb mobility was increased only in the Lig1 and VC1 treatments. Upon sulphur application, Fe, Mn, Cd, Pb and Zn mobility was not significantly affected in the C, AC and VC treatments, nor total Cd, Pb and Zn contents in maize shoots. Increased sulphate, Mn, Cd, Pb and Zn mobilities in soil together with related higher total S, Mn, Pb and Zn contents in shoots were observed in investigated treatments in the last sampling period. The highest biomass production and the lowest metal toxicity were seen in the VC treatments. These results were associated with effective metal immobilization and showed the trend of steady release of some nutrients. The highest remediation factors and total elemental content in maize shoots were recorded in the VC treatments. This increased phytoremediation efficiency by 400% for Cd and by 100% for Zn compared to the control. Considering the extreme metal load of the soil, it might be interesting to use highly metal-tolerant plants in future research. Future investigations could also explore the effect of carbonaceous additives on S oxidation, focusing on the specific microorganisms and redox reactions in the soil. In addition, the homogeneous distribution of the S rate in the soil should be considered, as well as longer observation times.

The establishment of phytoextraction crops on highly contaminated soils can be limited by metal toxicity. A recent proposal has suggested establishing support crops during the critical initial phase by metal immobilization through soil amendments followed by subsequent mobilization using elemental sulphur to enhance phytoextraction efficiency. This 'combined phytoremediation' approach is tested for the first time in a pot experiment with a highly contaminated soil. During a 14-week period, relatively metal-tolerant maize was grown in a greenhouse under immobilization (before sulphur (S) application) and mobilization (after S application) conditions with soil containing Cd, Pb and Zn contaminants. Apart from the control (C) sample, the soil was amended with activated carbon (AC), lignite (Lig) or vermicompost (VC) all in two different doses (dose 1~45 g additive kg-1 soil and dose 2~90 g additive kg-1 soil). Elemental S was added as a mobilization agent in these samples after 9 weeks. Biomass production, nutrient and metal bioavailability in the soil were determined, along with their uptake by plants and the resulting remediation factors. Before S application, Cd and Zn mobility was reduced in all the AC, Lig and VC treatments, while Pb mobility was increased only in the Lig1 and VC1 treatments. Upon sulphur application, Fe, Mn, Cd, Pb and Zn mobility was not significantly affected in the C, AC and VC treatments, nor total Cd, Pb and Zn contents in maize shoots. Increased sulphate, Mn, Cd, Pb and Zn mobilities in soil together with related higher total S, Mn, Pb and Zn contents in shoots were observed in investigated treatments in the last sampling period. The highest biomass production and the lowest metal toxicity were seen in the VC treatments. These results were associated with effective metal immobilization and showed the trend of steady release of some nutrients. The highest remediation factors and total elemental content in maize shoots were recorded in the VC treatments. This increased phytoremediation efficiency by 400% for Cd and by 100% for Zn compared to the control. Considering the extreme metal load of the soil, it might be interesting to use highly metal-tolerant plants in future research. Future investigations could also explore the effect of carbonaceous additives on S oxidation, focusing on the specific microorganisms and redox reactions in the soil. In addition, the homogeneous distribution of the S rate in the soil should be considered, as well as longer observation times.