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1.
Chemosphere ; 242: 125255, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31896180

RESUMO

A woody-biochar was added to waste biomass during a composting process. The resulting compost-char was amended to a metal contaminated soil and two plant species, L. perenne and E. sativa, were grown in a pot experiment to determine 1) plant survival and stress factors, 2) uptake of metals to plants and, 3) chemical characteristics of sampled soils and pore waters. Compost supplemented with biochar after the composting process were also tested, as well as a commercially available compost, for comparison. Co-composting with biochar hastened the composting process, resulting in a composite material of reduced odour, increased maturity, circum-neutral pH and increased moisture retention than compost (increase by 3% of easily removable water content). When amended to the soil, CaCl2 extractable and pore water metals s were reduced by all compost treatments with little influence of biochar addition at any tested dose. Plant growth success was promoted furthest by the addition of co-composted biochar to the test soil, especially in the case of E. sativa. For both tested plant species significant reductions in plant metal concentrations (e.g. 8-times for Zn) were achieved, against the control soil, by compost, regardless of biochar addition. The results of this study demonstrate that the addition of biochar into the composting process can hasten the stability of the resulting compost-char, with more favourable characteristics as a soil amendment/improver than compost alone. This appears achievable whilst also maintaining the provision of available nutrients to soils and the reduction of metal mobility, and improved conditions for plant establishment.


Assuntos
Brassicaceae/crescimento & desenvolvimento , Carvão Vegetal/química , Compostagem , Lolium/crescimento & desenvolvimento , Metais/análise , Madeira/química , Biodegradação Ambiental , Biomassa , Brassicaceae/química , Lolium/química , Modelos Teóricos , Solo/química , Poluentes do Solo/análise
2.
J Sci Food Agric ; 100(2): 885-890, 2020 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-31483055

RESUMO

BACKGROUND: The research focused on the evaluation of the impact of cover cropping on trace metals (Fe, Mn, Cu, Zn, Pb, Co and Cd) and nutrients in vineyard soils and Vitis vinifera L. For this purpose, two types of cover crops (Lolium perenne L. and Medicago sativa L.) and their mixture were planted between vine rows of Muscat white in the vineyard in South Crimea. Trace elements, nutrients and other parameters were analyzed in the soil layers, leaves and grapevines of control and cover cropped plots. RESULTS: The effect of cover cropping was dependent on applied plant species. Ryegrass (L. perenne L.) seems to compete with V. vinifera L. for nutrients - these were lower in the soil and vines of the treated plot. In parallel, lead (Pb) bioconcentration in grapevines was reduced. In contrast, under lucerne (M. sativa L.), nitrogen in the soil and vines, and trace metal bioconcentration (Fe, Pb and Co) were higher. CONCLUSIONS: Our results indicate that cover cropping can influence the chemical composition of soil and vines. This should be considered when selecting cover crops. © 2019 Society of Chemical Industry.


Assuntos
Produção Agrícola/métodos , Lolium/crescimento & desenvolvimento , Medicago/crescimento & desenvolvimento , Oligoelementos/análise , Vitis/química , Frutas/química , Frutas/crescimento & desenvolvimento , Frutas/metabolismo , Lolium/metabolismo , Medicago/metabolismo , Nutrientes/análise , Nutrientes/metabolismo , Solo/química , Especificidade da Espécie , Oligoelementos/metabolismo , Vitis/crescimento & desenvolvimento , Vitis/metabolismo
3.
J Agric Food Chem ; 67(45): 12558-12564, 2019 Nov 13.
Artigo em Inglês | MEDLINE | ID: mdl-31609622

RESUMO

All four stereoisomers of naturally occurring 6-(2-hydroxy-6-phenylhex-1-yl)-5,6-dihydro-2H-pyran-2-one (1) were synthesized by employing yeast-reduction products with high optical purity [from 95% enantiomeric excess (ee) to more than 99% ee], and then their phytotoxicities against lettuce and Italian ryegrass were evaluated. In the Italian ryegrass seedlings test, (6S,2'R)-1 showed the most potent and stereospecific activity against the shoots (IC50 = 260 µM) and roots (IC50 = 43.2 µM), with a significant difference from other stereoisomers. The highest seed germination inhibitory activity against Italian ryegrass seed was also observed in (6S,2'R)-1, showing a 53% germination ratio from the control at 1000 µM. This advantageous (6S,2'R) stereochemistry was employed in the syntheses of α,ß-dihydro, 2'-dehydroxy, and 2'-methoxy derivatives 13-15. By the test using these derivatives, the importance of the α,ß-unsaturated double bond and hydroxy group bonding to a chiral center on the 6-alkyl chain of 5,6-dihydro-α-pyrone for phytotoxicity was determined. In the test against lettuce, the 6S configuration and (6S,2'S) configuration were necessary for growth inhibition (IC50 = ca. 60 µM) and germination inhibition (63% germination ratio at 1000 µM), respectively.


Assuntos
Carbono/química , Herbicidas/farmacologia , Piranos/química , Carbono/farmacologia , Germinação/efeitos dos fármacos , Herbicidas/síntese química , Herbicidas/química , Alface/efeitos dos fármacos , Alface/crescimento & desenvolvimento , Lolium/efeitos dos fármacos , Lolium/crescimento & desenvolvimento , Estrutura Molecular , Piranos/farmacologia , Estereoisomerismo , Relação Estrutura-Atividade
4.
J Dairy Sci ; 102(11): 10439-10450, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31495628

RESUMO

The rising plate meter (RPM) is used to measure grass height, which subsequently is used in a calibration equation to estimate herbage mass (HM), an important parameter for optimization of feed management in grazing systems. The RPM is placed on the sward and measures the resistance of the sward toward the plate, which depends not only on grass length, but also on sward structure. The accuracy of the calibration equation for the RPM to estimate HM across grazing systems, however, has not yet been evaluated. Therefore, our aim was to analyze the effect of intensive grazing systems on RPM calibration for perennial ryegrass pastures. To do so, we studied 2 grazing systems: compartmented continuous grazing (CCG) and strip grazing (SG), which differ in key grazing characteristics, such as pre- and post-grazing heights and period of regrowth, that may influence tiller density and vertical flexibility of the sward. The experiment was performed from April until October in 2016 and 2017 with 60 dairy cows, at a fixed stocking rate of 7.5 cows per hectare. To calibrate the RPM, 256 direct measurements of HM >4 cm (i.e., above stubble) were collected by cutting and weighing plots of grass for CCG and SG. Our main interest was in the HM above stubble because this is consumed by cows. Herbage mass <4 cm represents the stubble left after grazing. Differences in HM <4 cm may (partially) explain differences in HM >4 cm between the grazing systems. Therefore, HM <4 cm was additionally measured on 4 out of every 8 plots per grazing system by cutting out quadrats to 0 cm with an electric grass trimmer. Our results showed an average error margin in our calibration equations of 25 to 31%, expressed as the root mean square error of prediction (RMSEP) as a percentage of the observed HM >4 cm. Differences between grazing systems were relatively small, and including grazing system as a factor in the regression model to explain the increase in HM per centimeter of grass did not reduce the RMSEP of the model to any relevant extent. On the other hand, HM <4 cm was significantly greater on CCG compared with SG, with 2,042 kg of DM per hectare for CCG and 1,676 kg of DM per hectare for SG. The HM <4 cm, however, is not used for grazing, and this difference was not reflected in the HM >4 cm. Our results indicate that we can use one region-specific calibration equation for perennial ryegrass pastures across intensive grazing systems, despite relatively large differences in pre- and post-grazing heights and period of regrowth.


Assuntos
Bovinos/fisiologia , Indústria de Laticínios/métodos , Lolium , Ração Animal/análise , Animais , Calibragem , Indústria de Laticínios/economia , Indústria de Laticínios/instrumentação , Feminino , Lactação , Lolium/crescimento & desenvolvimento , Leite/química , Países Baixos , Poaceae , Distribuição Aleatória , Análise de Regressão , Estações do Ano
5.
Environ Monit Assess ; 191(10): 626, 2019 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-31501951

RESUMO

Two kitchen garden soils (A and B) sampled in contaminated areas were amended using phosphates in sustainable quantities in order to reduce the environmental availability of potentially toxic inorganic elements (PTEs) and to favour the availability of alkali, alkali earth and micronutrients. The environmental availability of PTEs was evaluated using a potential plant for revegetation of contaminated soils (ryegrass) and a mixture of low molecular weight organic acids. Despite the highest contamination level of B, the concentration of metals was highest in the ryegrass shoots grown on A for the two harvests. These results correlated well with those obtained using low molecular weight organic acids for Cd, Zn and Cu, whereas this mixture failed to represent the transfer of nutrients due to the presence of biological and physiological mechanisms. The statistical differences between the biomass of ryegrass obtained at the first and the second harvests were attributed to the decrease of available potassium, implicated in the growth and development of plants. Phosphates increased the ratios Zn/Cd, Zn/Pb and Zn/Cu up to 176 ± 48, 38 ± 6 and 80 ± 12, respectively, and made possible the reduction of the concentration of Cd and Pb in the shoots of ryegrass by 22% and 25%, respectively. The concentration of Zn in the shoots of ryegrass from the first and the second harvests grown on soil A were in the range 1050-2000 mg kg-1, making this plant a potential biomass to (i) produce biosourced catalysts for organic chemistry applications in a circular economy concept and (ii) limit human exposure to commercial Lewis acids. A preliminary application was identified.


Assuntos
Lolium/crescimento & desenvolvimento , Metais Pesados/metabolismo , Fosfatos/administração & dosagem , Poluentes do Solo/química , Solo/química , Biodegradação Ambiental , Biomassa , Cádmio/metabolismo , Fenômenos Químicos , Cobre/metabolismo , Poluição Ambiental , Humanos , Chumbo/metabolismo , Lolium/metabolismo , Desenvolvimento Sustentável , Zinco/metabolismo
6.
J Dairy Sci ; 102(10): 9495-9504, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31351712

RESUMO

Through clearing and use of fertilizer and legumes, areas of southwestern Australia's unique coastal sand plains can support relatively low-cost dairies. However, the ancient, highly weathered nature of the soils in this region makes the dairies susceptible to a range of threats, including nutrient leaching and erosion. Despite this, Western Australian dairy cows typically produce up to 5,500 L of milk per head annually supported by inorganic nitrogen (N) fertilizer (commonly 50:50 urea and ammonium sulfate) at rates up to <320 kg of N/ha per year. Where hotspots exist (up to 2,000 kg of N/ha per year), total N exceeds pasture requirements. We investigated plant and soil bacteria responses to N fertilizer rates consistent with Australian legislated production practices on dairy farms for pure and mixed swards of white clover (Trifolium repens) and Italian ryegrass (Lolium multiflorum) in a long-term pasture experiment in controlled glasshouse conditions. Although the soil bacterial community structure at phylum level was similar for white clover and Italian ryegrass, relative abundances of specific subgroups of bacteria differed among plant species according to the N fertilizer regimen. Marked increases in relative abundance of some bacterial phyla and subphyla indicated potential inhibition of N cycling, especially for N hotspots in soil. Ammonium concentration in soil was less correlated with dominance of some N-cycling bacterial phyla than was nitrate concentration. Changes in bacterial community structure related to altered nutrient cycling highlight the potential for considering this area of research in policy assessment frameworks related to nutrient loads in dairy soils, especially for N.


Assuntos
Bactérias/efeitos dos fármacos , Bovinos/metabolismo , Fertilizantes/microbiologia , Lolium/crescimento & desenvolvimento , Leite/metabolismo , Nitrogênio/farmacologia , Microbiologia do Solo , Trifolium/crescimento & desenvolvimento , Animais , Austrália , Bactérias/crescimento & desenvolvimento , Feminino , Itália , Nitratos/farmacologia , Nitrogênio/metabolismo
7.
Ecotoxicol Environ Saf ; 182: 109418, 2019 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-31327493

RESUMO

Cigarette filters (butts) are currently the most abundant form of anthropogenic litter on the planet, yet we know very little about their environmental impacts on terrestrial ecosystems, including plant germination and primary production. When discarded, filters contain a myriad of chemicals resulting from smoking tobacco and some still contain unsmoked remnants. A greenhouse experiment was used to assess the impacts of discarded filters of regular or menthol cigarette, either from unsmoked, smoked, or smoked cigarettes with remnant tobacco, on the growth and development of Lolium perenne (perennial ryegrass) and Trifolium repens (white clover). After 21 days, shoot length and germination success were significantly reduced by exposure to any type of cigarette filter for the grass and clover. Although total grass biomass was not measurably affected, the root biomass and root:shoot ratio were less in the clover when exposed to filters from smoked regular cigarettes and those with remnant tobacco. Cigarette filters caused an increase in chlorophyll-a in clover shoots and an increase in chlorophyll-b in grass shoots. Accordingly, whilst the chlorophyll a:b ratio was increased in the clover exposed to cigarette filters, it was decreased in grass. This study indicates the potential for littered cigarette filters to reduce growth and alter short-term primary productivity of terrestrial plants.


Assuntos
Lolium/efeitos dos fármacos , Poluentes do Solo/toxicidade , Produtos do Tabaco/toxicidade , Trifolium/efeitos dos fármacos , Clorofila A , Ecossistema , Fabaceae , Lolium/crescimento & desenvolvimento , Poaceae , Fumaça , Tabaco , Trifolium/crescimento & desenvolvimento
8.
Bull Environ Contam Toxicol ; 103(2): 336-341, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31297552

RESUMO

Phytoremediation experiments were carried out to assess the ability of different herbaceous buffer strips to absorb metals. Results revealed the Medicago sativa buffer strip had the best removal capacity for copper, lead, and cadmium in the runoff and seepage flow. Copper and lead content in M. sativa were significantly higher than in Lolium perenne and Poa pratensis (p < 0.05). Cadmium content in P. pratensis was significantly higher than in L. perenne and M. sativa(p < 0.05). Total accumulation of copper and lead in M. sativa buffer strips was 13.45 mg kg-1 and 1.01 mg kg-1, respectively. Total cadmium accumulation was approximately 0.50 mg kg-1 in both M. sativa and P. pratensis. Overall, results indicated that using M. sativa in the buffer strips was optimal for the remediation of copper, lead, and cadmium in sewage water.


Assuntos
Lolium/crescimento & desenvolvimento , Medicago sativa/crescimento & desenvolvimento , Metais Pesados/análise , Poa/crescimento & desenvolvimento , Esgotos/química , Poluentes Químicos da Água/análise , Adsorção , Biodegradação Ambiental , China , Modelos Teóricos , Movimentos da Água
9.
Bull Environ Contam Toxicol ; 103(2): 330-335, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31263937

RESUMO

The immobilization effect and mechanism of nano-hydroxyapatite(NHAP) on Pb in the ryegrass rhizosphere soil were studied by root-bag experiment. The speciation analysis results revealed that the residual Pb concentrations in the rhizosphere soil significantly increased after NHAP application. The acid-soluble and reducible Pb concentrations significantly decreased, indicating that NHAP had obviously immobilized Pb. Meanwhile, NHAP significantly promoted the secretion of tartaric acid from ryegrass roots, resulting the rhizosphere soil pH had been below that of the control group. This helped to relieve the stress of Pb on ryegrass, also promoted the dissolution of NHAP, resulting the formation of stable precipitation with more Pb ions. NHAP increased the rhizosphere soil pH by 0.03 to 0.17, which promoted the conversion of Pb to non-utilizable bioavailability. The total Pb mass balance indicated only a very small proportion Pb transferred to the shoots through ryegrass roots. The formation of pyromorphite by Pband NHAP in soil was accordingly to interpret the dominant mechanism for Pb immobilization.


Assuntos
Durapatita/química , Chumbo/análise , Lolium/crescimento & desenvolvimento , Nanoestruturas/química , Rizosfera , Poluentes do Solo/análise , Adsorção , Disponibilidade Biológica , Concentração de Íons de Hidrogênio , Chumbo/metabolismo , Lolium/metabolismo , Minerais/química , Modelos Teóricos , Fosfatos/química , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/metabolismo , Solo/química , Poluentes do Solo/metabolismo , Tartaratos/metabolismo
10.
Sci Total Environ ; 685: 428-441, 2019 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-31176228

RESUMO

This study argues that several metrics are necessary to build up a picture of yield gain and nitrogen losses for ryegrass sheep pastures. Metrics of resource use efficiency, nitrous oxide emission factor, leached and emitted nitrogen per unit product are used to encompass yield gain and losses relating to nitrogen. These metrics are calculated from field system simulations using the DAYCENT model, validated from field sensor measurements and observations relating to crop yield, fertilizer applied, ammonium in soil and nitrate in soil and water, nitrous oxide and soil moisture. Three ryegrass pastures with traditional management for sheep grazing and silage are studied. As expected, the metrics between long-term ryegrass swards in this study are not very dissimilar. Slight differences between simulations of different field systems likely result from varying soil bulk density, as revealed by a sensitivity analysis applied to DAYCENT. The field with the highest resource use efficiency was also the field with the lowest leached inorganic nitrogen per unit product, and vice versa. Field system simulation using climate projections indicates an increase in nitrogen loss to water and air, with a corresponding increase in biomass. If we simulate both nitrogen loss by leaching and by gaseous emission, we obtain a fuller picture. Under climate projections, the field with the lowest determined nitrous oxide emissions factor, had a relatively high leached nitrogen per product amongst the three fields. When management differences were investigated, the amount of nitrous oxide per unit biomass was found to be significantly higher for an annual management of grazing only, than a silage harvest plus grazing, likely relating to the increased period of livestock on pasture. This work emphasizes how several metrics validated by auto-sampled data provide a measure of nitrogen loss, efficiency and best management practise.


Assuntos
Agricultura/métodos , Lolium/crescimento & desenvolvimento , Nitrogênio/análise , Biomassa , Clima , Monitoramento Ambiental , Fertilizantes , Óxido Nitroso/análise
11.
BMC Res Notes ; 12(1): 311, 2019 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-31151479

RESUMO

OBJECTIVES: The objective of this study was to establish transcriptome assemblies of Festulolium hybrids under salt stress, and identify genes regulated across the hybrids in response to salt stress. The development of transcriptome assemblies for Festulolium hybrids and cataloguing of genes regulated under salt stress will facilitate further downstream studies. RESULTS: Plants were grown at three salt concentrations (0.5%, 1% and 1.5%) and phenotypic and transcriptomic data was collected. Salt stress was confirmed by progressive loss of green leaves as salt concentration increased from 0 to 1.5%. We generated de-novo transcriptome assemblies for two Festulolium pabulare festucoid genotypes, for a single Festulolium braunii genotype, and a single F. pabulare loloid genotype. We also identified 1555 transcripts that were up regulated and 1264 transcripts that were down regulated in response to salt stress in the Festulolium hybrids. Some of the identified transcripts showed significant sequence similarity with genes known to be regulated during salt and other abiotic stresses.


Assuntos
Festuca/genética , Regulação da Expressão Gênica de Plantas , Hibridização Genética/genética , Lolium/genética , Estresse Salino/genética , Transcriptoma , Festuca/crescimento & desenvolvimento , Perfilação da Expressão Gênica , Genes de Plantas/genética , Sequenciamento de Nucleotídeos em Larga Escala , Lolium/crescimento & desenvolvimento , Folhas de Planta/genética , Folhas de Planta/crescimento & desenvolvimento , Transcrição Genética
12.
Ecotoxicol Environ Saf ; 181: 155-163, 2019 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-31181386

RESUMO

In this study, comparative investigations on the effects of crop straw and its derived biochars on soil Cd and Zn mobility and availability were conducted. Crop straws (i.e. maize straw, rapeseed straw, and wheat straw) and their derived biochars were incubated with two contaminated alkaline soils (FX and TG soils) at 2.5% (w/w). The changes of soil properties like pH, EC, organic matter content, and dissolved organic matter content were investigated along with metal mobility, speciation distribution, and accumulation in ryegrass (Lolium multiflorum Lam.). Results indicated biochar, especially those were high in pH, enhanced soil pH (>0.2 units, p < 0.05), whereas a continuous reduction of soil pH was observed among treatments with crop straws. Both soil EC and the organic matter content increased with the application of both crop straws and biochars. In term of metals, Cd and Zn mobility were reduced with 6-14%/1-5% and 6-27%/7-15% reduction in the DTPA extractable Cd and Zn contents in TG and FX soil treatments, respectively. Moreover, distinct changes of metals in different fractions were also observed (acid soluble and reducible fraction → oxidizable fraction in straw treatments; acid soluble fraction → reducible soluble fraction in biochar amendments). Furthermore, the biological analysis revealed that the growth of ryegrass was promoted, but the accumulation of metals in ryegrass shoots was reduced, especially in MS700 treatment. Apart from the amendments, metal immobilization efficiencies were negatively correlated with the contamination status. Despite that, a higher rate of biochar application (>10%) could dramatically reduce the amount of available metal in soil extracts, except for Zn in FX soil treatments. This present work demonstrated that biochars, especially those produced at a higher temperature, are superior to crop straws to immobilize metals in soils. However, the remediation efficiencies were strongly restricted by soil pH and contamination status.


Assuntos
Cádmio/análise , Carvão Vegetal , Poluentes do Solo/análise , Zinco/análise , Produtos Agrícolas , Lolium/crescimento & desenvolvimento , Lolium/metabolismo , Metalurgia , Solo/química
13.
Environ Sci Pollut Res Int ; 26(18): 18451-18464, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31044381

RESUMO

Petroleum contamination and its remediation via plant-based solutions have got increasing attention by environmental scientists and engineers. In the current study, the physiological and growth responses of two diesel-tolerant plant species (tolerance limit: 1500-2000 mg/kg), Italian ryegrass (Lolium multiflorum) and Birdsfoot trefoil (Lotus corniculatus), have been investigated in vegetable oil- and diesel oil-amended soils. A long-term (147-day) greenhouse pot experiment was conducted to differentiate the main focus of the study: physical and chemical effects of oil (vegetable and diesel) in freshly spiked soils via evaluating the plant performance and hydrocarbon degradation. Moreover, plant performance was evaluated in terms of seed germination, plant shoot biomass, physiological parameters, and root biomass. Addition of both diesel oil and vegetable oil in freshly spiked soils showed deleterious effects on seedling emergence, root/shoot biomass, and chlorophyll content of grass and legume plants. Italian ryegrass showed more sensitivity in terms of germination rate to both vegetable and diesel oil as compared to non-contaminated soils while Birdsfoot trefoil reduced the germination rate only in diesel oil-impacted soils. The results of the current study suggest that both physical and chemical effects of oil pose negative effects of plant growth and root development. This observation may explain the phenomenon of reduced plant growth in aged/weathered contaminated soils during rhizoremediation experiments.


Assuntos
Lolium/efeitos dos fármacos , Lotus/efeitos dos fármacos , Petróleo/toxicidade , Microbiologia do Solo , Poluentes do Solo/toxicidade , Solo/química , Biodegradação Ambiental , Biomassa , Germinação/efeitos dos fármacos , Lolium/crescimento & desenvolvimento , Lolium/metabolismo , Lotus/crescimento & desenvolvimento , Lotus/metabolismo , Microbiota/efeitos dos fármacos , Óleos Vegetais/toxicidade , Brotos de Planta/efeitos dos fármacos , Rizosfera , Plântula/efeitos dos fármacos
14.
Sci Total Environ ; 677: 250-262, 2019 Aug 10.
Artigo em Inglês | MEDLINE | ID: mdl-31055104

RESUMO

Compost can provide nitrogen (N) and especially phosphorous (P) available for plant growth, thus representing a potential alternative to chemical P-fertilizers a non-renewable resource. However, little is known about their residual capacity to provide plant-available P. In this study four compost: a green waste compost (GWC), one from anaerobically-digested bio-waste (DC), one from sewage sludge (SSC), and one from bio-waste (BWC), were compared (10 and 20 Mg VS ha-1) in a ryegrass pot test (112 days), for their N- and P-relative mineral fertilizer equivalence (MFE; %) vs. a chemical fertilizer (NPK). After the test period, the exploited treatments were tested for their MFE during an additional ryegrass growth cycle (112 days) in an N-rich environment (N+). After 112 days, the pot test showed that DC and SSC produced dry biomass in the same range as did NPK, attaining the best N-MFE (80-100%) and P-MFE (100-125%), whereas GWC and BWC performed poorly (60-80 and 80-90%; N-MFE and P-MFE). At the end of the first growth cycle, DC and SSC still showed relevant Olsen-P (20-30 mg kg-1). This was reflected in the best ryegrass P-MFE in DC and SSC at the end of the second growth cycle (N+), after 224 days (100-110%), whereas BWC and GWC poorly performed (90-95%). DC and SSC may therefore represent valuable sources of N available for plant nutrition in the short term, and also represent medium-term valuable P sources, alternative to rock phosphate P fertilizers. This promising approach need further field-scale investigation to confirm the medium-long term capacity of composts to be alternative to rock phosphate P fertilizers.


Assuntos
Compostagem , Fertilizantes/análise , Lolium/metabolismo , Fósforo/metabolismo , Disponibilidade Biológica , Lolium/crescimento & desenvolvimento
15.
Environ Sci Pollut Res Int ; 26(18): 17986-17995, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31065986

RESUMO

In order to evaluate the resistance of lawn plant to Co2+ at germination stage and discuss its concentration property at adult stage, four kinds of lawn plant which have some growth advantages in Co2+ polluted environment were selected as experimental materials in this research. They are tall fescue, timothy grass, inflorescences, and annual ryegrass. The results show that the evaluation of resistance to Co2+ of tall fescue's seed is the highest; the evaluation of resistance to Co2+ of annual ryegrass seed is the lowest. The low consistence Co2+ could improve the seed germination. With Co2+ concentration increase, the accumulation coefficient of four plants increased at first and decreased later; the accumulation coefficient of underground portion is higher than the accumulation coefficient of aboveground; with Co2+ concentration increase, the transfer coefficient of four plants have a remarkable decline. In these plants, the accumulation coefficient of tall fescue and annual ryegrass is bigger than other two plants. As the concentration of Co2+ treatment increased to 100 mg/kg, the aboveground enrichment of Co2+ in F. elata reached 75 mg/kg, followed by L. multiflorum (68.9 mg/kg), P. pratense (48.8 mg/kg), and D. glomerata (27.2 mg/kg).The highest underground enrichment of Co2+ in F. elata reached 836.46 mg/kg, in contrast to the lowest underground enrichment in D. glomerata, 264.67 mg/kg. It shows that fescue and annual ryegrass have a better enrichment property to Co2+ and have a better prospect for the treatment of cobalt-contaminated soil. This research could provide some scientific basis and main technical approach for the soil contaminated by Co2+.


Assuntos
Cobalto/análise , Festuca/efeitos dos fármacos , Germinação/efeitos dos fármacos , Lolium/efeitos dos fármacos , Plântula/efeitos dos fármacos , Poluentes do Solo/análise , Biodegradação Ambiental , Cobalto/toxicidade , Festuca/química , Festuca/crescimento & desenvolvimento , Lolium/química , Lolium/crescimento & desenvolvimento , Modelos Teóricos , Plântula/química , Sementes/química , Sementes/efeitos dos fármacos , Solo/química , Poluentes do Solo/toxicidade
16.
Chemosphere ; 229: 481-488, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31091489

RESUMO

The objective of this study was to determine the influence of the DC electric current in the physicochemical properties of soil. The electric current may induce changes in pH and electric conductivity that will be reflected in the distribution of the electric potential in the soil specimen. This information will be used for the development of a phytoremediation technology amended with electric current. The results showed that low or moderate voltage gradients (0.67 V/cm) induced small changes in physicochemical properties of soil that do not compromise plant survival. The selected voltage gradient was used in electro-phytoremediation tests in soil contaminated with heavy metals (Cd, Co, Cr, Cu, Pb and Zn). Two plants species adapted to the soil and climate conditions were selected (Brassica rapa L. subsp. rapa and Lolium perenne L.). The electric field enhanced the plant growing, mainly in L. perenne, and increased the phytoremediation of the 6 metals. Mixed cultures of the two plant species showed interesting results for large scale applications.


Assuntos
Técnicas Eletroquímicas/métodos , Recuperação e Remediação Ambiental/métodos , Metais Pesados , Poluentes do Solo , Solo/química , Biodegradação Ambiental , Brassica/crescimento & desenvolvimento , Condutividade Elétrica , Concentração de Íons de Hidrogênio , Lolium/crescimento & desenvolvimento , Metais Pesados/análise , Metais Pesados/metabolismo , Poluentes do Solo/análise , Poluentes do Solo/metabolismo
17.
Chemosphere ; 230: 510-518, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31125879

RESUMO

Soil heavy metal contamination is a serious environmental problem needed to be addressed due to the toxicities of metals to both humans and living organisms. In this study, the remediation efficiencies of washing-coupled phytoremediation on Cd and Zn contaminated soils were evaluated with multiple washing reagents (i.e., hydrochloric acid (HCl), ethylene diamine tetraacetic acid (EDTA), nitrilotriacetic acid (NTA), several biodegradable natural low molecular mass organic acids (LMMOAs)) and ryegrass (Lolium perenne L.). Results indicated that soil washing with different reagents (at 100 mM) effectively removed metals from contaminated soils with the rates ranged from 4.73% to 81.0% and from 12.3% to 43.5% for Cd and Zn, respectively. Metal varieties and the properties washing reagents affected the detoxification performance. As for Cd, the removal rates decreased from over 80% to less than 10% in the order of EDTA > HCl > NTA > LMMOAs. By comparison, HCl and LMMOAs had higher removal efficiencies for Zn than other chelating reagents. The leaching of metals in the acid-extractable fraction was the main contribution to the overall metal removed. Additionally, soil nutrient contents, Ca specifically, were significantly decreased after washing, and the germination and growth of ryegrass were partly inhibited. Despite that, soil biota and enzyme activities responded differently among different treatments. This research also showed LMMOAs, especially citric acid (CA), were more suitable than HCl, EDTA, and NTA as reagents for the combined soil washing and phytoremediation, regarding their comparable metal removal efficiencies and less disturbing on soil fertilities and plant growth.


Assuntos
Cádmio/análise , Quelantes/química , Recuperação e Remediação Ambiental/métodos , Lolium/efeitos dos fármacos , Poluentes do Solo/análise , Zinco/análise , Biodegradação Ambiental , Quelantes/toxicidade , Estudos de Viabilidade , Humanos , Lolium/crescimento & desenvolvimento , Solo/química
18.
Plant Sci ; 283: 211-223, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31128691

RESUMO

Drought resistance is a crucial attribute of plants and to properly decipher its mechanisms, a valuable plant model is required. Lolium multiflorum is a forage grass characterized by a low level of abiotic stress resistance, whereas Festuca arundinacea is recognized as a species with drought resistance, including both stress avoidance and tolerance strategies. These two species can be crossed with each other. Two closely related L. multiflorum/F. arundinacea introgression forms with distinct levels of field drought resistance were involved, thus enabling the dissection of this complex trait into its crucial components. The processes occurring in roots were shown to be the most significant for the expression of drought resistance. Thus, the analysis was focused on the root architecture and the accumulation of selected hormones, primary metabolites and glycerolipids in roots. The introgression form, with a higher resistance to field water deficit was characterized by a deeper soil penetration by its roots, and it had a higher accumulation level of primary metabolites, including well recognized osmoprotectants, such as proline, sucrose or maltose, and an increase in phosphatidylcholine to phosphatidylethanolamine ratio compared to the low resistant form. A comprehensive model of root performance under water deficit conditions is presented here for the first time for the grass species of the Lolium-Festuca complex.


Assuntos
Festuca/anatomia & histologia , Lolium/anatomia & histologia , Raízes de Plantas/anatomia & histologia , Desidratação , Festuca/crescimento & desenvolvimento , Festuca/metabolismo , Metabolismo dos Lipídeos , Lolium/crescimento & desenvolvimento , Lolium/metabolismo , Folhas de Planta/anatomia & histologia , Folhas de Planta/metabolismo , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/metabolismo , Brotos de Planta/anatomia & histologia , Brotos de Planta/crescimento & desenvolvimento , Brotos de Planta/metabolismo , Água/metabolismo
19.
Environ Sci Pollut Res Int ; 26(17): 17489-17498, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31020530

RESUMO

Aided phytoremediation was studied for 48 weeks with the aim of reducing extractable and phytoavailable toxic elements and producing potential marketable biomass. In this sense, biomass of ryegrass was produced under greenhouse on two contaminated garden soils that have been amended with two successive additions of phosphates. After the first addition of phosphates, seeds of ryegrass were sown and shoots were harvested twice. A second seedling was performed after carefully mixing the roots from the first production (used as compost), soils and phosphates. Forty-eight weeks after starting the experiments, the concentrations of Cd, Pb, Zn, Cu, Fe, and Mn extracted using the rhizosphere-based method were generally lower than those measured before the addition of phosphates and cultivation (except for Pb and Fe in the most contaminated soil). The concentrations of metals in the shoots of ryegrass from the second production were lower than those from the first (except for Al). The best results were obtained with phosphates and were the most relevant in the lowest contaminated soil, demonstrating that the available metal concentrations have to be taken into account in the management of contaminated soils. In view of the concentration of metals defined as carcinogens, mutagens, and reprotoxics (e.g., Cd, Pb) and those capable to be transformed into Lewis acids (e.g., Zn, Fe), the utilization of ryegrass in the revegetation of contaminated soils and in risk management may be a new production of marketable biomass. The development of phytomanagement in combination with this type of biomass coincided with the view that contaminated soils can still represent a valuable resource that should be used sustainably.


Assuntos
Lolium/crescimento & desenvolvimento , Metais/análise , Raízes de Plantas/química , Poluentes do Solo/análise , Biodegradação Ambiental , Biomassa , Lolium/química , Metais/química , Rizosfera , Poluentes do Solo/química
20.
Artigo em Inglês | MEDLINE | ID: mdl-30965589

RESUMO

Wood ash produced through cellulose manufacturing has agricultural uses due to its neutralizing power, like that of commercial products, in addition to providing key soil nutrients such as Ca, Mg, K, and P. However, this industrial waste can possess heavy metal(oid)s that bioaccumulate in the food chain. The objective of this study was to determine the effect of wood ash (WA) on the physicochemical properties of an Ultisol, the mobility of heavy metal(oid)s (As, Cd, Cr, Pb, and Ni) in the soil-plant-water system, and the nutritional response (N, P, and K) of ryegrass (Lolium perenne L.). The experiment was conducted in pots, under greenhouse conditions, using a completely randomized design. Ryegrass was grown in pots containing mixtures of WA plus soil at 7.5, 15, 30, and 75 g kg-1, commercial lime plus soil at 1.5 g kg-1, and unamended soil as a control. Heavy metal(oid)s were analyzed by inductively coupled plasma optical emission spectrometry (ICP-OES). All WA doses favored an increase in pH and the availability of P, Ca, Mg, Na, K, Cu, and Zn in soil and N, P, and K absorption in ryegrass. WA favored the availability and later absorption of heavy metal(oid)s by ryegrass (staying mainly in the roots). Heavy metal(oid)s mobility in the soil-plant-water system was as follows: Cr > Pb > Ni > As.


Assuntos
Resíduos Industriais/análise , Metais Pesados/química , Nutrientes/química , Poluentes do Solo/química , Madeira/química , Agricultura , Compostos de Cálcio/química , Lolium/química , Lolium/crescimento & desenvolvimento , Óxidos/química , Raízes de Plantas/química , Poluentes do Solo/análise
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