Mechanisms of silicon-mediated alleviation of abiotic stresses in higher plants: a review

Although silicon (Si) is the second most abundant element both on the surface of the Earth's crust and in soils, it has not yet been listed among the essential elements for higher plants. However, the beneficial role of Si in stimulating the growth and development of many plant species has been generally recognized. Silicon is known to effectively mitigate various abiotic stresses such as manganese, aluminum and heavy metal toxicities, and salinity, drought, chilling and freezing stresses. However, mechanisms of Si-mediated alleviation of abiotic stresses remain poorly understood. The key mechanisms of Si-mediated alleviation of abiotic stresses in higher plants include: (1) stimulation of antioxidant systems in plants, (2) complexation or co-precipitation of toxic metal ions with Si, (3) immobilization of toxic metal ions in growth media, (4) uptake processes, and (5) compartmentation of metal ions within plants. Future research needs for Si-mediated alleviation of abiotic stresses are also discussed.     

Nitrogen nutrition in cotton and control strategies for greenhouse gas emissions: a review

Cotton (Gossypium hirustum L.) is grown globally as a major source of natural fiber. Nitrogen (N) management is cumbersome in cotton production systems; it has more impacts on yield, maturity, and lint quality of a cotton crop than other primary plant nutrient. Application and production of N fertilizers consume large amounts of energy, and excess application can cause environmental concerns, i.e., nitrate in ground water, and the production of nitrous oxide a highly potent greenhouse gas (GHG) to the atmosphere, which is a global concern. Therefore, improving nitrogen use efficiency (NUE) of cotton plant is critical in this context. Slow-release fertilizers (e.g., polymer-coated urea) have the potential to increase cotton yield and reduce environmental pollution due to more efficient use of nutrients. Limited literature is available on the mitigation of GHG emissions for cotton production. Therefore, this review focuses on the role of N fertilization, in cotton growth and GHG emission management strategies, and will assess, justify, and organize the researchable priorities. Nitrate and ammonium nitrogen are essential nutrients for successful crop production. Ammonia (NH₃) is a central intermediate in plant N metabolism. NH₃ is assimilated in cotton by the mediation of glutamine synthetase, glutamine (z-) oxoglutarate amino-transferase enzyme systems in two steps: the first step requires adenosine triphosphate (ATP) to add NH₃ to glutamate to form glutamine (Gln), and the second step transfers the NH₃ from glutamine (Gln) to α-ketoglutarate to form two glutamates. Once NH₃ has been incorporated into glutamate, it can be transferred to other carbon skeletons by various transaminases to form additional amino acids. The glutamate and glutamine formed can rapidly be used for the synthesis of low-molecular-weight organic N compounds (LMWONCs) such as amides, amino acids, ureides, amines, and peptides that are further synthesized into high-molecular-weight organic N compounds (HMWONCs) such as proteins and nucleic acids.     

Monitoring of pesticide residues in a cotton crop soil

Abstract

This paper reports on the residues of methyl parathion (O,O‐dimethyl O‐4‐nitrophenyl phosphorothioate), trifluralin (α, α, α‐trifluoro‐2, 6‐dinitro‐N, N‐dipropyl‐p‐toluidine), endosulfan [(1, 4, 5, 6, 7, 7‐hexachloro‐8, 9, 10‐trinorborn‐5‐en‐2, 3‐ylenebismethylene) sulfite] and dimethoate (O, O‐dimethyl S‐methylcarbamoylmethyl phosphorodithioate) in a cotton crop soil. Soil samples (0–15 cm) were collected at different periods from the cotton crop farm and subjected to Soxhlet extraction. The extracted material was analysed after clean‐up by a HP5890 II gas Chromatograph equipped with a ⁶³Ni electron‐capture detector (ECD‐⁶³Ni) and fitted with a 25m x 0,2mm i.d. fused silica capillary column [Ultra‐2 (5% phenylmethyl polysiloxane)]. The recoveries of the pesticide residues from the spiked control soil were determined after Soxhlet extraction and C₁₈ cartridges clean‐up by using radiotracer techniques with the corresponding ¹⁴C‐pesticides. The results show that in the cotton crop soil the pesticide residues under study were present in the range of 0.1 to 0.4 mg ? kg^‐1. Endosulfan was found to be rapidly degraded in the soil and formed a sulfate metabolite.     

Monitoring of pesticide residues in a cotton crop soil

This paper reports on the residues of methyl parathion (O,O-dimethyl O-4-nitrophenyl phosphorothioate), trifluralin (alpha, alpha, alpha-trifluoro-2,6-dinitro-N,N-dipropyl-p-toluidine), endosulfan [(1, 4, 5, 6, 7, 7-hexachloro-8, 9, 10-trinorborn-5-en-2, 3-ylenebismethylene) sulfite] and dimethoate (O, O-dimethyl S-methylcarbamoylmethyl phosphorodithioate) in a cotton crop soil. Soil samples (0-15 cm) were collected at different periods from the cotton crop farm and subjected to Soxhlet extraction. The extracted material was analysed after clean-up by a HP5890 II gas chromatograph equipped with a 63Ni electron-capture detector (ECD-63Ni) and fitted with a 25 m x 0.2 mm i.d. fused silica capillary column [Ultra-2 (5% phenylmethyl polysiloxane)]. The recoveries of the pesticide residues from the spiked control soil were determined after Soxhlet extraction and C18 cartridges clean-up by using radiotracer techniques with the corresponding 14C-pesticides. The results show that in the cotton crop soil the pesticide residues under study were present in the range of 0.1 to 0.4 mg.kg-1. Endosulfan was found to be rapidly degraded in the soil and formed a sulfate metabolite.     

Insecticide residues in cotton crop soil

Dimethoate, monocrotophos, triazophos, deltamethrin, cypermethrin and endosulfan were applied to a cotton crop soil located at Nurpur village, Punjab, India. The insecticides were applied sequentially at recommended dosages in cotton fields by foliar application in 1995, 1996 and 1998. Soil samples were collected from the cotton crop farms and extracted with acetone. The extracted material was analysed by a gas liquid chromatograph (GLC) equipped with an 63Ni electron-capture detector (ECD-63Ni). Recovery data was obtained by fortifying soil with insecticide. The average recoveries from the fortified soil samples were 76-92% for organophosphorous compounds and 90-98% for synthetic pyrethroids and organochlorines. The results showed that the insecticide residues under study were present in the range of 1.16 to 41.97 ng g(-1) d.wt.soil. The pattern of dissipation of the insecticides used was similar for the duration of the crop. Half lives of the insecticides ranged from 7 to 22 days. Except endosulfan none of the other insecticides used were leached below 15 cm. Endosulfan was found to be rapidly degraded in the soil and formed a sulfate metabolite. Persistence and dissipation pattern in soils with history of exposure to the insecticide compared to non-history soils were similar.     

Nitrogen deposition in California forests: a review

Atmospheric concentrations and deposition of the major nitrogenous (N) compounds and their biological effects in California forests are reviewed. Climatic characteristics of California are summarized in light of their effects on pollutant accumulation and transport. Over large areas of the state dry deposition is of greater magnitude than wet deposition due to the arid climate. However, fog deposition can also be significant in areas where seasonal fogs and N pollution sources coincide. The dominance of dry deposition is magnified in airsheds with frequent temperature inversions such as occur in the Los Angeles Air Basin. Most of the deposition in such areas occurs in summer as a result of surface deposition of nitric acid vapor (HNO3) as well as particulate nitrate (NO3-) and ammonium (NH4+). Internal uptake of gaseous N pollutants such as nitrogen dioxide (NO2), nitric oxide (NO), HNO3, peroxyacetyl nitrate (PAN), ammonia (NH3), and others provides additional N to forests. However, summer drought and subsequent lower stomatal conductance of plants tend to limit plant utilization of gaseous N. Nitrogen deposition is much greater than S deposition in California. In locations close to photochemical smog source areas, concentrations of oxidized forms of N (NO2, HNO3, PAN) dominate, while in areas near agricultural activities the importance of reduced N forms (NH3, NH4+) significantly increases. Little data from California forests are available for most of the gaseous N pollutants. Total inorganic N deposition in the most highly-exposed forests in the Los Angeles Air Basin may be as high as 25-45 kg ha(-1) year(-1). Nitrogen deposition in these highly-exposed areas has led to N saturation of chaparral and mixed conifer stands. In N saturated forests high concentrations of NO3- are found in streamwater, soil solution, and in foliage. Nitric oxide emissions from soil and foliar N:P ratios are also high in N saturated sites. Further research is needed to determine the ecological effects of chronic N deposition, and to develop appropriate management options for protecting water quality and managing plant nutrient resources in ecosystems which no longer retain excess N.     

Anti-herbivore activity of soluble silicon for crop protection in agriculture: a review

Environmental Science and Pollution Research - Silicon (Si) is considered an important component for plant growth, development, and yield in many crop species. Silicon is also known to reduce plant...     

Hg、Cd污染对2种外生菌根真菌氮素营养吸收的影响

以从中国西南林区分离获得的外生菌根真菌彩色豆马勃(Pisolithus tinctorius 715,简称Pt715)、松乳菇(Lactarius delicious.ex Gray-1(简称Ld-1)、Lactarius delicious.exPink-2(简称Ld-2)、Lactarius delicious.ex White-3(简称Ld-3))为供试菌种,研究Hg、Cd对其吸收氮素的影响,从而筛选出在营养吸收上具有重金属耐受性的菌株。结果表明,重金属对外生菌根真菌吸收氮素营养的影响因重金属元素种类、真菌种类和氮素形态不同而异,Hg、Cd基本不会抑制供试菌种对有机态氮的吸收,而对NH+4-N、NO-3-N的吸收有不同程度的抑制或促进作用,但无明显的规律可循;Ld-1菌株具有一定的耐Hg性,在培养液中加入不同浓度的Hg后,Ld-1菌株对3种氮源的吸收均未受到明显抑制,相反在高Hg浓度下还促进了对NH+4-N、NO-3-N的吸收。Ld-1菌株有可能在Hg的胁迫下诱导合成了新的特异性蛋白,Hg与特异性蛋白结合从而缓解了其污染胁迫。     

Leaching of seven pesticides currently used in cotton crop in Mato Grosso State-Brazil

This study aimed to evaluate the leaching of pesticides and the applicability of the Attenuation Factor (AF) Model to predict their leaching. The leaching of carbofuran, carbendazim, diuron, metolachlor, alpha and beta endosulfan and chlorpyrifos was studied in an Oxisol using a field experiment lysimeter located in Dom Aquino-Mato Grosso. The samples of percolated water were collected by rain event and analyzed. Chemical and physical soil attributes were determined before pesticide application to the plots. The results showed that carbofuran was the pesticide that presented a higher leaching rate in the studied soil, so was the one representing the highest contamination potential. From the total carbofuran applied in the soil surface, around 6% leached below 50 cm. The other pesticides showed lower mobility in the studied soil. The calculated values to AF were 7.06E-12 (carbendazim), 5.08E-03 (carbofuran), 3.12E-17 (diuron), 6.66E-345 (alpha-endosulfan), 1.47E-162 (beta-endosulfan), 1.50E-06 (metolachlor), 3.51E-155 (chlorpyrifos). AF Model was useful to classify the pesticides' potential for contamination; however, that model underestimated pesticide leaching.     

Sustainable supply chain management and green technologies: a bibliometric review of literature

Environmental Science and Pollution Research - To attain ecological sustainability and transition to sustainable supply chain management (SSCM), effective technological innovation (TI) and solid...     

COVID-19 and municipal solid waste (MSW) management: a review

Environmental Science and Pollution Research - Municipal solid waste (MSW) represents an inevitable by-product of human activity and a major crisis for communities across the globe. In recent...     

Cadmium stress in rice: toxic effects,tolerance mechanisms,and management: a critical review

Cadmium (Cd) is one of the main pollutants in paddy fields, and its accumulation in rice (Oryza sativa L.) and subsequent transfer to food chain is a global environmental issue. This paper reviews the toxic effects, tolerance mechanisms, and management of Cd in a rice paddy. Cadmium toxicity decreases seed germination, growth, mineral nutrients, photosynthesis, and grain yield. It also causes oxidative stress and genotoxicity in rice. Plant response to Cd toxicity varies with cultivars, growth condition, and duration of Cd exposure. Under Cd stress, stimulation of antioxidant defense system, osmoregulation, ion homeostasis, and over production of signaling molecules are important tolerance mechanisms in rice. Several strategies have been proposed for the management of Cd-contaminated paddy soils. One such approach is the exogenous application of hormones, osmolytes, and signaling molecules. Moreover, Cd uptake and toxicity in rice can be decreased by proper application of essential nutrients such as nitrogen, zinc, iron, and selenium in Cd-contaminated soils. In addition, several inorganic (liming and silicon) and organic (compost and biochar) amendments have been applied in the soils to reduce Cd stress in rice. Selection of low Cd-accumulating rice cultivars, crop rotation, water management, and exogenous application of microbes could be a reasonable approach to alleviate Cd toxicity in rice. To draw a sound conclusion, long-term field trials are still required, including risks and benefit analysis for various management strategies.     

The atmosphere in England and Wales: an environmental management review

Air pollution in England and Wales is reviewed to identify priorities for management and research. The main human drivers of emissions are the production and consumption of energy and materials, disposal of waste, transport and land use. Pollutants are assigned to seven types: (i) nuisance (e.g. odour, noise), (ii) toxic, (iii) acidifying/eutrophying, (iv) photochemical oxidant precursors, (v) radionuclides, (vi) stratospheric ozone depleting substances and (vii) greenhouse gases. Dominant trends in activity and emissions are highlighted. New technologies and fuels are partially decoupling emissions from activity in power generation, industry and transport, but the gains are being offset by growth in demand and output in all major sectors. The evidence for impacts on human health, the atmosphere and other environmental systems is discussed. Priorities for management are climate change, ground-level ozone, acidification and eutrophication by nitrogen, urban air quality and nuisance pollution. Management responses require greater foresight, technological improvements and new instruments to control polluting activities. More scientific information is needed on the impacts on human health, quality of life and ecosystems, and on the links between different types of pollution. The policy challenges include generating energy sustainably, reducing transport impacts, devising effective economic instruments, improving societal awareness and contributing to cleaner global development.     

Protected area designation and management in a world of climate change: A review of recommendations

Climate change is challenging conservation strategies for protected areas. To summarise current guidance, we systematically compiled recommendations from reviews of scientific literature (74 reviews fitting inclusion criteria) about how to adapt conservation strategies in the face of climate change. We focussed on strategies for designation and management of protected areas in terrestrial landscapes, in boreal and temperate regions. Most recommendations belonged to one of five dominating categories: (i) Ensure sufficient connectivity; (ii) Protect climate refugia; (iii) Protect a few large rather than many small areas; (iv) Protect areas predicted to become important for biodiversity in the future; and (v) Complement permanently protected areas with temporary protection. The uncertainties and risks caused by climate change imply that additional conservation efforts are necessary to reach conservation goals. To protect biodiversity in the future, traditional biodiversity conservation strategies should be combined with strategies purposely developed in response to a warming climate.Supplementary InformationThe online version contains supplementary material available at 10.1007/s13280-022-01779-z.     

A review of root exudates and rhizosphere microbiome for crop production

Environmental Science and Pollution Research - Increasing crop yields and ensuring food security is a major global challenge. In order to increase crop production, chemical fertilizers and...     

Nitrogen modulates early growth and physio-biochemical attributes in fragrant rice grown under cadmium and multiwall carbon nanotubes stresses

Environmental Science and Pollution Research - Nitrogen (N) modulates plant growth, but its impact on the early growth and physio-biochemical characteristics of rice under cadmium (Cd) and...     

Correction to: Sustainable supply chain management and green technologies: a bibliometric review of literature

Environmental Science and Pollution Research -     

Ambient ozone and crop loss: establishing a cause-effect relationship

This paper provides the results of a retrospective mathematical analysis of the US NCLAN (National Crop Loss Assessment Network) open-top chamber data. Some 77% of the 73 crop harvests examined, showed no statistically significant yield differences between NF (non-filtered open-top chamber) and AA (chamberless, ambient air) treatments (no easily discernable chamber effects on yield). However, among these cases only seven acceptable examples showed statistically significant yield reductions in NF compared to the CF (charcoal filtered open-top chamber) treatment. An examination of the combined or cumulative hourly ambient O3 frequency distribution for cases with yield loss in NF compared to a similar match of cases without yield loss showed that the mean, median and the various percentiles were all higher (>/= 3 X) in the former in contrast to the latter scenario. The combined frequency distribution of hourly O3 concentrations for the cases with yield loss in NF were clearly separated from the corresponding distribution with no yield loss, at O3 concentrations > 49 ppb. Univariate linear regressions between various O3 exposure parameters and per cent yield losses in NF showed that the cumulative frequency of occurrence of O3 concentrations between 50 and 87 ppb was the best predictor (adjusted R2 = 0.712 and p = 0.011). This analysis also showed that the frequency distribution of hourly concentrations up to 87 ppb O3 represented a critical point, since the addition of the frequency distributions of > 87 ppb O3 did not improve the R2 values. In fact as the frequency of hourly O3 concentrations included in the regression approached 50-100 ppb, the R2 value decreased substantially and the p value increased inversely. Further, univariate linear regressions between the frequencies of occurrence of various O3 concentrations between 50 and 90 ppb and: (a) cases with no yield difference in NF and (b) cases with yield increase in NF compared to the CF treatment (positive effect) provided no meaningful statistical relationship (adjusted R2 = 0.000) in either category. These results support the basis that additional evaluation of the frequency of occurrence of hourly O3] concentrations between 50 and 87 ppb for cases with the yield reductions could provide a meaningful ambient O3 standard, objective or guideline for vegetation.     

Integrated waste management through producers and consumers education: composting of vegetable crop residues for reuse in cultivation

As part of the design of an integrated waste management scheme through the use of the PRECEDE/PROCEED model in the area of Crete, data concerning the applicability of composting in various agricultural wastes was considered as necessary. Vegetable residues from tomato, cucumber, eggplant, and pepper crops were collected, shredded and composted either alone or with the use of olive press cake, olive tree leaves, and branches and vine branches as bulking agents. Seven random combinations--mixtures of the above materials were composted using windrows, where additional four similar windrows were made up by approximately 10 m3 of the above mentioned vegetable crop residues. All windrows were turned four times during the eight weeks thermophylic phase, with the help of a mechanical turner. A large number of physiochemical parameters were monitored in the raw materials, at the end of the thermophylic phase and at the end of the maturation phase. The temperature which was monitored daily, recorded the highest values (above 55 degrees C) in the windrows where bulking agents were used. All raw vegetable crop residues and their mixtures presented increased electrical conductivity values (above 5 mS/cm and up to 9.7 mS/cm) resulting to end products with respectively high EC values (above 3 mS/cm and up to 15 mS/cm) probably due to the presence of large amounts of soil, rich in fertilisers, attached to the roots of the plants. There was no detection of any remains of the 13 pesticides for which all 11 composts were tested for. The accuracy of the results was tested through a recovery test of the pesticides in mature compost, resulting to acceptable recovery values.     

Integrated waste management in a zone of northern Italy: compost production and use, and analytical control of compost, soil, and crop

Agricultural soils of two Italian maize farms were treated for five years with an industrially produced high-quality compost. Cattle manure and the usual mineral fertilizer were used for comparison purposes. The effects of the organic and mineral fertilizer treatments were studied by analyzing the compost and manure, cultured soils, and harvested material. The grain yield was also determined. Organic fertilization improved soil pH, CEC, content of organic matter and NPK. Soil respiration and N mineralization were found to be higher than in the purely mineral-treated soil. Plant K take-up was improved, whereas grain yield was not affected. It was confirmed that organic fertilization, particularly compost use, maintained and increased soil fertility. The study demonstrated the feasibility of using in loco analytical facilities to follow the entire recycling process-from waste to compost production-and the use of the final product in the field.