Concentrations In Aboveground Parts Research Articles

GIS-Facilitated Germination of Stored Seeds from Five Wild-Growing Populations of Campanula pelviformis Lam. and Fertilization Effects on Growth, Nutrients, Phenol Content and Antioxidant Potential

This study was designed to bridge extant research gaps regarding the vulnerable and protected local endemic Campanula pelviformis, a wild edible green traditionally consumed in Crete (Greece) with agro-alimentary and medicinal interest as well as ornamental value. The C. pelviformis ecological profile was generated using the climate and temperature conditions prevailing in its wild habitats through mapping of natural distribution linked with online bioclimatic databases in geographical information systems. We tested the germination of seeds from five wild-growing populations at four different temperatures (10, 15, 20 and 25 °C) and under different light conditions (light/dark and darkness), and we performed fertilization trails [integrated nutrient management (INF), chemical fertilization (ChFe), control] examining morphological and physiological characteristics, above- and below-ground macro- and micronutrients and phenol contents, as well as their antioxidant capacity. We found population and temperature effects on seed germination with their interaction being statistically significant. Campanula pelviformis germinated better at 10 and 15 °C (>85% for all populations) with no preference on light conditions (98.75% and 95% in light and dark conditions). The INF application increased root dry mass, chlorophyll content index and chlorophyll fluorescence compared to other treatments and was beneficial for macro- and micronutrient concentrations in above-ground parts compared to previously studied wild-growing material, while below-ground parts were positively impacted by both fertilization types. Total phenols and antioxidant capacity were both increased by ChFe fertilization. The data furnished herein permitted the re-evaluation and upgrade of its sustainable exploitation potential in different economic sectors.

Potential for the Accumulation of PTEs in the Biomass of Melilotus albus Med. Used for Biomethane Production

In this paper, a possible use of white sweet clover (Melilotus albus Med.) for phytoremediation was assessed. The plants were grown on soils with naturally occurring concentrations of potentially toxic elements (PTEs). First, the content of PTEs was determined in plant biomass and in soil samples using: (a) Optical emission spectrometry with inductively coupled plasma to determine Sb, As, Cd, Cu, Ni, Pb, and Se, and (b) thermal decomposition, amalgamation, and atomic absorption spectrometry to determine Hg. The effectiveness of Melilotus albus Med. (M. albus) for phytoremediation was evaluated using the bioconcentration factor (BCF). The phytoextraction potential of M. albus was determined using bioaccumulation factor (BAC) and translocation factor (TF) values. The highest concentration of PTEs in roots was detected for zinc (10.56 mg/kg of dry weight, DW) and copper (5.128 mg/kg of DW). Similarly, the highest concentration in above-ground parts of the plant was detected for zinc and copper (12.638 and 4.0 mg/kg of DW, respectively). Although the values were relatively high, the effectiveness of the absorption of these PTEs by plant biomass from the soil was relatively very low. BAC and BCF were always lower than 1. On the other hand, the results suggested that M. albus effectively transports PTEs (only for Zn, Pb and Hg) from roots to shoots, because TF was always higher than 1. However, the accumulation of PTEs from soils with a natural abundance of PTEs was not excessive in comparison to conventional maize silage. Therefore, there is no potential risk of biomethane production in biogas plants when biomass from M. albus is used.

Coupling sprinkler freshwater irrigation with vegetable species selection as a sustainable approach for agricultural production in farmlands with a history of 50-year wastewater irrigation

Soil contamination and crop risks of heavy metal(loid)s are widely reported after the long-term irrigation of treated wastewater, causing an adverse influence on agricultural sustainability. Here, we collected soils after 50 years of wastewater irrigation to cultivate cabbage (Brassica pekinensis L.), rape (Brassica chinensis L.), carrots (Daucus carota L.), and potatoes (Solanum tuberosum L.), using surface and sprinkler irrigation with freshwater and wastewater. In general, we found the statistically insignificant influence of short-term freshwater irrigation on the soil and vegetable metal(loid) concentrations. Most of the vegetables had potential adverse health risks with the relatively lower risks in carrots and potatoes, and most of the risks were contributed by As and Cd. Nevertheless, we observed negligible health risks for all studied metal(loid)s in potatoes under the freshwater irrigations. Besides, compared to wastewater irrigations, freshwater irrigations produced lower Cd health risks in all four vegetable species. Sprinkler irrigation with freshwater was a favorable approach for reducing the uptake of metal(loid)s from soils and the metal(loid) concentrations in aboveground parts. Our study highlights the possibility of reducing vegetable metal(loid) risks in contaminated farmlands via a combined approach of coupling the short-term decrease in their levels in irrigation water with vegetable species selection.

Seasonal variation in toxic steroidal alkaloids of foothill death camas (Zigadenus paniculatus)

Death camas (Zigadenus spp.) is a common poisonous plant in North America with plants occurring in a wide variety of habitats with species of toxic concern occurring primarily in meadows, grasslands, shrublands, and mountains. The toxicity of Zigadenus species has been attributed to a series of steroidal alkaloids. The objective of this study was to evaluate zygacine and total steroidal alkaloid concentrations in different plant tissues of Zigadenus paniculatus as a function of plant maturity. Death camas plants were collected at two locations at different developmental growth stages representing vegetative, flower, seed pod, and shattered seed pod stages. Zygacine represented greater than 50% of the total steroidal alkaloids at all developmental stages. In bulbs, total steroidal alkaloid and zygacine concentrations did not change significantly as a function of plant phenology, and concentrations were lower than what were observed in above ground plant parts. Total steroidal alkaloid and zygacine concentrations in above ground parts were highest at early vegetative growth stages and decreased over the growing season. In plant reproductive parts, total steroidal alkaloid and zygacine concentrations increased until maturity and then decreased as the plant senesced. The concentrations of steroidal alkaloids reported here suggest that the toxic risk associated with death camas is greatest in the early vegetative growth stages followed by the flower and pod stages. There is a toxic risk to livestock as long as the plant is present, and caution should be taken when grazing livestock in areas with death camas until the plant senesces.

Accumulation and concentration of nitrogen, phosphorus and potassium in Jerusalem artichoke in a semi-arid region

Jerusalem artichoke (Helianthus tuberosus L.) has been recognized as being a biomass crop for energy and livestock forage production. In this study, 26 Jerusalem artichoke clones previously collected from 24 provinces of China were grown under semiarid conditions in 2008 and 2011. At harvest, nitrogen (N), phosphorus (P) and potassium (K) concentrations and accumulations were measured for all clones and levels of both were higher overall for 2008 than 2011, with statistically reasonable results for both years. Notably, N and K concentrations in aboveground parts were higher than in tubers for most clones, yet the tuber P concentration was consistently higher than in aboveground parts. Comparing with other forage and energy plants, it demonstrates that under optimal conditions, diverse Jerusalem artichoke clones could meet the requirements of either energy production or livestock forage feed. Based on N, P and K accumulation and concentration profiles, the 26 Jerusalem artichoke clones clustered into six groups. Three clones of one cluster, CQ-1, GZ-1 and HUN-3, are recommended for use as biomass energy materials due to the lower N concentration level in aboveground parts and higher N concentration level in tubers, while 16 clones are recommended for use as forage due to the higher N concentration level in aboveground parts. The phenotypic traits described in this work should facilitate quantitative trait locus mapping and the subsequent use of clone germplasms for development of improved varieties suited to specific growth conditions and applications.

Effect of Pseudomonas fluorescens and pyoverdine on the phytoextraction of cesium by red clover in soil pots and hydroponics.

With the aim of improving the phytoextraction rate of cesium (Cs), the effect of Pseudomonas fluorescens ATCC 17400 and its siderophore pyoverdine (PVD) on the uptake of Cs by red clover was studied in soil pots. This work also provides a mechanistic understanding of the Cs-bacteria (or PVD)-illite-plant interactions by using a simplified experimental design, i.e., hydroponics with either Cs in solution or Cs-spiked illite in suspension. For soil spiked with 11.2mmolkg-1 (1480mgkg-1) of Cs, 0.43% of total Cs was taken up by red clover in 12days (119μmolg-1 (16mgg-1) of Cs dry matter in roots and 40μmolg-1 (5mgg-1) in shoots). In hydroponics with Cs in solution (0.1mmolL-1 or 13mgL-1), 75% of Cs was taken up vs. only 0.86% with Cs-spiked illite suspension. P. fluorescens and PVD did not increase Cs concentrations in aboveground parts and roots of red clover and even decreased them. The damaging effect of PVD on red clover growth was demonstrated with the biomass yielding 66% of the control in soil pots (and 100% mortality after 12days of exposition) and only 56% in hydroponics (78% with illite in suspension). Nonetheless, PVD and, to a lesser extent, P. fluorescens increased the translocation factor up to a factor of 2.8. This study clearly showed a direct damaging effect of PVD and to a lower extent the retention of Cs by biofilm covering both the roots and illite, both resulting in the lower phytoextraction efficiency.

The effect of sewage sludge on the growth and species composition of the sward and the content of heavy metals in plants and urban soil

Abstract The effect of sewage sludge on the growth and species composition of the sward and the content of heavy metals in plants and urban soil. The determination of the sludge fertilising infl uence for the growth and composition of the urban grasslands’ swards and heavy metals concentration in above-ground parts of the plants was the aim of the study. The study was conducted on four research plots along the main roads in Białystok. The plots were seeded with two mixtures of lawn grasses (Eko and Roadside) and three doses of sludge were applied: 0 (control), 7.5 and 15 kg/m2. The study also included the determination of concentrations of Cd, Cr, Cu, Pb and Zn in soil and in the above-ground parts of lawn grasses and selected physical and chemical properties of soils fertilized with different doses of sludge. The dose of 7.5 kg/m2 increased the plant dry matter on average by 53%, the dose of 15 kg/m2 - on average by 90%. The largest effect of fertilization was found for lightest soil. Under these conditions, grass dry matter fertilized with 7.5 kg/m2 sludge was almost doubled, and fertilized with the dose of 15 kg/m2 was almost three times larger than in not fertilized areas. Perennial ryegrass (Lolium perenne L.) was the dominant species in the sward. Perennial ryegrass constituted on average 71% of all grass species in the areas fertilized with sewage sludge in the dose of 7.5 kg/m2, while on the areas fertilized with 15 kg/m2 - about 81%, and on not fertilized ones - 50% on average. Bioconcentration factor in the study allowed for estimating the plants ability to collect heavy metals present in the soil. Based on these results, it was found that the rate of bioconcentration of Cd, Cr, Cu and Pb was the highest in August, which may indicate the ease of downloading these metals by plants, particularly high mobility of metals during this period, and lower in October and June

Evaluation of the possibility to use the plant-microbe interaction to stimulate radioactive 137Cs accumulation by plants in a contaminated farm field in Fukushima, Japan.

Field experiments in a contaminated farmland in Nihonmatsu city, Fukushima were conducted to assess the effectiveness of the plant-microbe interaction on removal of radiocesium. Before plowing, 93.3% of radiocesium was found in the top 5 cm layer (5,718 Bq kg DW(-1)). After plowing, Cs radioactivity in the 0-15 cm layer ranged from 2,037 to 3,277 Bq kg DW(-1). Based on sequential extraction, the percentage of available radiocesium (water soluble + exchangeable) was fewer than 10% of the total radioactive Cs. The transfer of (137)Cs was investigated in three agricultural crops; komatsuna (four cultivars), Indian mustard and buckwheat, inoculated with a Bacillus or an Azospirillum strains. Except for komatsuna Nikko and Indian mustard, inoculation with both strains resulted in an increase of biomass production by the tested plants. The highest (137)Cs radioactivity concentration in above-ground parts was found in Bacillus-inoculated komatsuna Nikko (121 Bq kg DW(-1)), accompanied with the highest (137)Cs TF (0.092). Furthermore, komatsuna Nikko-Bacillus and Indian mustard-Azospirillum associations gave the highest (137)Cs removal, 131.5 and 113.8 Bq m(-2), respectively. Despite the beneficial effect of inoculation, concentrations of (137)Cs and its transfer to the tested plants were not very high; consequently, removal of (137)Cs from soil would be very slow.

Heavy metals in plants and substrate from simulated extensive green roofs

Recycled brick could be used in green roofs but may pose environmental risk due to its heavy metal contents. In this study, concentrations of eight heavy metals (Cr, Ni, Cu, Zn, As, Cd, Pb, and Hg) in three edible and medicinal plants (Sedum lineare Thunb (SL), Sedum sarmentosum Bunge (SS) and Portulaca oleracea L. (PO)), and in recycled brick substrate from simulated extensive green roofs, were investigated in Spring and Autumn. The results showed that most heavy metal concentrations in plants (aboveground parts) in April were significantly lower than those in October, and significantly increased year on year. None of the three species showed superiority or inferiority in all heavy metal concentrations at all the four samplings. Heavy metal concentrations in aboveground parts were all significantly lower than in roots, and significantly lower than in substrate except for Zn. The three species could not be used as food a year after they were sown; only PO collected in April can be harvested as medicine, mainly due to Pb concentrations exceeding the standard. Cd concentration in substrate increased and Ni decreased during the experiment, while the others kept unchanged. The substrate was polluted according to the standard due to its high Cd concentration which mainly came from recycled brick.

Assessment of fly ash-aided phytostabilisation of highly contaminated soils after an 8-year field trial: Part 2. Influence on plants

Aided phytostabilisation is a cost-efficient technique to manage metal-contaminated areas, particularly in the presence of extensive pollution. Plant establishment and survival in highly metal-contaminated soils are crucial for phytostabilisation success, as metal toxicity for plants is widely reported. A relevant phytostabilisation solution must limit metal transfer through the food chain. Therefore, this study aimed at evaluating the long-term efficiency of aided phytostabilisation on former agricultural soils highly contaminated by cadmium, lead, and zinc. The influence of afforestation and fly ash amendments on reducing metal phytoavailability was investigated as were their effects on plant development. Before being planted with a tree mix, the site was divided into three plots: a reference plot with no amendment, a plot amended with silico-aluminous fly ash and one with sulfo-calcic fly ash. Unlike Salix alba and Quercus robur, Alnus glutinosa, Acer pseudoplatanus and Robinia pseudoacacia grew well on the site and accumulated, overall, quite low concentrations of metals in their leaves and young twigs. This suggests that these three species have an excluder phenotype for Cd, Zn and Pb. After 8 years, metal availability to A. glutinosa, A. pseudoplatanus and R. pseudoacacia, and translocation to their above-ground parts, strongly decreased in fly ash-amended soils. Such decreases fit well together with the depletion of CaCl 2-extractable metals in amended soils. Although both fly ashes were effective to decrease Cd, Pb and Zn concentrations in above-ground parts of trees, the sulfo-calcic ash was more efficient.

Antimony and Arsenic Uptake by Plants in an Abandoned Mining Area

The degree of antimony (Sb) and arsenic (As) pollution and their bioavailability in mining‐affected grassland soils were determined. Antimony and As concentrations in aboveground parts of plants, collected in three consecutive years, were measured to investigate their uptake capacity, food chain contamination, and ecological risks. Total Sb and As contents in soils ranged from 60 to 230 mg/kg and from 42 to 4530 mg/kg, respectively, indicating a high degree of pollution of soils. The mobile fractions of Sb (0.02–0.27% of the total Sb content) and As (0.02–0.70% of the total As content) in soils, which reflect the plant‐available portion, are extremely low compared to total Sb and As contents in soils. The Sb and As contents in plants were also very low in both study areas. This lower accumulation of Sb and As in the plants is attributed to the low bioavailability of Sb and As in mine soils. Antimony and As contents in some plants were lower than the controls, and the concentrations in some plants were slightly higher than the normal grass mean level but were less than the phytotoxic or toxic levels for human or livestock consumption. The results of this study demonstrate that the plants growing in these mining areas, which have evolved As and Sb tolerance and detoxification capacity, can be cultivated to phytostabilize the metalloid‐contaminated mining sites.

Arsenic accumulation by two brake ferns growing on an arsenic mine and their potential in phytoremediation

In an area near an arsenic mine in Hunan Province of south China, soils were often found with elevated arsenic levels. A field survey was conducted to determine arsenic accumulation in 8 Cretan brake ferns ( Pteris cretica) and 16 Chinese brake ferns ( Pteris vittata) growing on these soils. Three factors were evaluated: arsenic concentration in above ground parts (fronds), arsenic bioaccumulation factor (BF; ratio of arsenic in fronds to soil) and arsenic translocation factor (TF; ratio of arsenic in fronds to roots). Arsenic concentrations in the fronds of Chinese brake fern were 3–704 mg kg −1, the BFs were 0.06–7.43 and the TFs were 0.17–3.98, while those in Cretan brake fern were 149–694 mg kg −1, 1.34–6.62 and 1.00–2.61, respectively. Our survey showed that both ferns were capable of arsenic accumulation under field conditions. With most of the arsenic being accumulated in the fronds, these ferns have potential for use in phytoremediation of arsenic contaminated soils.

Use of summer harvested common reed ( Phragmites australis) as nutrient source for organic crop production in Sweden

Increasing nutrient levels in lakes contribute to environmental problems such as overgrowth and eutrophication. Decreasing soil nutrient levels in organic farming systems result in reduced plant growth. During July and August, nutrient concentration in aboveground parts of the widely distributed aquatic plant common reed ( Phragmites australis) is relatively high. The purpose of this work was to identify and analyse technical and logistic systems useful in removing reed biomass from the lake and using it as nutrient supply in organic crop production. The area studied for reed harvest was limited to the “Kållandsundet” drainage basin in Sweden. 160 ha are scheduled for harvesting each year. One strategy studied was to chop the harvested material and spread it directly on farmland. Another was to compost the material before spreading, and a third was to use the harvested biomass as raw material in biogas production and spread the by-product (sludge) on farmland. The energy balances for the three systems were calculated to −0.35, −0.43 and +4.05 MJ kg −1 harvested dry matter, respectively. The biogas strategy produces both large amounts of energy in the gas and nutrients in a form easily available to agricultural plants. The economics of the system are sensitive to changes in income provided by the gas produced and in the cost of the chopping operation. The alternative of chopping and spreading the reed directly as green manure does not require large investments or complicated processing plants, but produces no useful energy and the risks for nitrogen leakage are higher than for the biogas alternative. The compost alternative has the least favourable characteristics among the three strategies studied. The operations at the compost plant are costly and no useful energy is produced. For all three alternatives, the total economics are highly improved if the positive effects of nutrient removal from the lake are included in the calculations.

Mercury toxicity in plants

Mercury poisoning has become a problem of current interest as a result of environmental pollution on a global scale. Natural emissions of mercury form two-thirds of the input; manmade releases form about one-third. Considerable amounts of mercury may be added to agricultural land with sludge, fertilizers, lime, and manures. The most important sources of contaminating agricultural soil have been the use of organic mercurials as a seed-coat dressing to prevent fungal diseases in seeds. In general, the effect of treatment on germination is favorable when recommended dosages are used. Injury to the seed increases in direct proportion to increasing rates of application. The availability of soil mercury to plants is low, and there is a tendency for mercury to accumulate in roots, indicating that the roots serve as a barrier to mercury uptake. Mercury concentration in aboveground parts of plants appears to depend largely on foliar uptake of Hg0 volatilized from the soil. Uptake of mercury has been found to be plant specific in bryophytes, lichens, wetland plants, woody plants, and crop plants. Factors affecting plant uptake include soil or sediment organic content, carbon exchange capacity, oxide and carbonate content, redox potential, formulation used, and total metal content. In general, mercury uptake in plants could be related to pollution level. With lower levels of mercury pollution, the amounts in crops are below the permissible levels. Aquatic plants have shown to be bioaccumulators of mercury. Mercury concentrations in the plants (stems and leaves) are always greater when the metal is introduced in organic form. In freshwater aquatic vascular plants, differences in uptake rate depend on the species of plant, seasonal growthrate changes, and the metal ion being absorbed. Some of the mercury emitted from the source into the atmosphere is absorbed by plant leaves and migrates to humus through fallen leaves. Mercury-vapor uptake by leaves of the C3 speciesoats, barley, and wheat is five times greater than that by leaves of the C4 species corn, sorghum, and crabgrass. Such differential uptake by C3 and C4 species is largely attributable to internal resistance to mercury-vapor binding. Airborne mercury thus seems to contribute significantly to the mercury content of crops and thereby to its intake by humans as food. Accumulation, toxicity response, and mercury distribution differ between plants exposed through shoots or through roots, even when internal mercury concentrations in the treated plants are similar. Throughfall and litterfall play a significant role in the cycling and deposition of mercury. The possible causal mechanisms of mercury toxicity are changes in the permeability of the cell membrane, reactions of sulphydryl (-SH) groups with cations, affinity for reacting with phosphate groups and active groups of ADP or ATP, and replacement of essential ions, mainly major cations. In general, inorganic forms are thought to be more available to plants than are organic ones.