Ceramic Aggregate Sorption and Desorption Chemistry: Implications for Use as a Component of Soilless Media

Ceramic aggregates (Turface® and Profile®) are common soilless media components, but their sorption/desorption chemistry is poorly understood. We investigated: labile (readily desorb-able or readily plant-available) ion concentrations; the effect of rinsing and soaking pretreatments on labile ions; sorption of applied nutrients; and nutrient uptake from the aggregates by plants. Variability in labile ions was extremely high among bags of aggregates. Manganese, boron, magnesium, calcium, sulfur and potassium were most likely to desorb in excess for plants. Phosphorus, iron, copper and zinc were sorbed by the aggregates; only copper was found nearly deficient in plant tissue. Rinsing and soaking pretreatments adjusted labile ions to more suitable concentrations for plants. However, growth data suggested a worst-case scenario of high levels of labile ions may not be mitigated by these pretreatments. With frequent leaching after planting or where the aggregates are a minor component of media, excessive nutrient uptake would likely be limited.     

The Use of Compost for the Reclamation of Saline and Alkaline Soils

? The results of a two year field experiment verified hypotheses concerning use of compost to improve saline and alkaline soils. The addition of compost to such soils was expected to release acids which would ultimately lead to the replacement of exchangeable sodium by calcium. The addition of compost would also stabilize soil structure and enhance plant growth. It was shown that the addition of municipal solid waste compost is equivalent, or even superior to the addition of gypsum, the common amendment used to reclaim alkaline soils. The overall effect of treatments on soil fertility was evident from yields of crops. The combined application of compost and gypsum raised yields to levels expected in good commercial fields.     

Use of Food Label Information by Trinidad Consumers and Implications for National Health

Nutritional information on food labels helps consumers make informed decisions about what they chose to consume. This study, conducted among 320 consumers in Trinidad, West Indies, examined consumers' use of various informational components of the label and the influence of health-related factors on use of such information. The study found that, although there was a fairly high reading of food label information, fats and sodium information were not given the required attention. Six variables—(a) diabetes; (b) allergies; (c) gender; (d) level of schooling; (e) fast food consumption; and (f) fiber consumption—significantly impacted the use of food label information.     

Sorption of the fluoroquinolone antibiotic ofloxacin by aquatic sediments: influence of biofilm development at the sediment-water interface

Journal of Soils and Sediments - Sorption to sediments and biofilms is thought to be a crucial mechanism controlling the fate and transport of emerging contaminants. Biofilm growth changes the...     

Kinetic and Thermodynamic Behavior on the Sorption of Clindamycin from an Aqueous Medium by Modified Surface Zeolitic Tuffs

Clindamycin (CLD), an antibiotic derivate of lincomycin, is widely used; the presence of this drug in the wastewater and the environment could produce resistance in bacteria. In this work, the sorption of this drug by two surfactant-modified zeolitic tuffs was studied considering contact time, initial concentration, pH, and temperature. The kinetic behavior indicates that the equilibrium times were between 15 and 12 h for all materials, and the results were best adjusted to Ho and Mc Kay model. The highest adsorption was obtained with the hexadecyltrimethylammonium-modified zeolitic tuff from Oaxaca, Mexico (1.56 mg/g). The sorption isotherms obtained showed a linear behavior, indicating a partition mechanism. The thermodynamic parameters were determined from the isotherms at different temperatures and Van Ho equation; the processes are exothermic and not spontaneous. The best pH for the adsorption is between 8 and 11. The results show that the modified zeolitic tuffs are potential materials for the adsorption of CLD from water.     

Effect of Microorganisms on the Sorption of Lanthanides by Quartz and Goethite at the Different pH Values

The effect of Rhodopseudomonas pallustris bacterium on the sorption of 16 isotopes of lanthanides by quartz and goethite at different pHs values was studied. pH of sorption solution and affinity of elements to surface seems to be most important parameters in the interactions between metal ions and surfaces of biological and mineral sorbents. At acidic (pH°4) and neutral (pH°7) conditions these interactions was affected by electrostatic forces; at alkaline conditions (pH°9) the mechanism of lanthanides precipitation was dominant. Microorganisms sufficiently affected on lanthanides sorption by quartz at acidic and neutral conditions, but largest one was at pH°7. They increased sorption of all elements by goethite at pH°4. There was negligible effect of bacteria on the sorption of lanthanides at pH°7 and 9 by goethite that demonstrates greater affinity of the elements to goethite surface. Microorganisms increased concentration of lanthanides in the nonexchangeable states on the surfaces of quartz at pH°7 and 9, and on the surface of goethite at pH°7 in comparison to the minerals alone. It may be attributed to formation of low-soluble complexes of lanthanides with organic substances, produced by bacterium.     

熏蒸条件下有机肥部分替代化肥对西瓜生长及养分利用的影响

基于田间大棚试验,采用等量养分原则,分析生物有机肥、蚯蚓粪、鸡粪等不同有机肥部分替代化肥对西瓜生长、产量、品质以及养分利用的影响。结果表明,与单施化肥相比,有机肥部分替代化肥均不同程度提高了西瓜叶绿素含量、光合性能、产量及品质,其中以蚯蚓粪与化肥配施效果最佳,其光合性能显著高于单施化肥,产量提高了33.63%,可溶性糖、可溶性蛋白及维生素C含量分别增加了14.07%,14.47%和17.52%。有机肥部分替代化肥施肥处理的肥料利用率高于单施化肥,土壤养分元素依存率低于单施化肥,以蚯蚓粪配施化肥作用效果最为显著,氮、磷、钾肥利用率分别为26.02%,5.67%和29.89%,土壤氮、磷、钾素依存率分别为20.96%,20.32%和31.55%。熏蒸处理的西瓜枯萎病发病率整体低于未熏蒸处理,其中熏蒸条件下蚯蚓粪部分替代化肥施肥处理西瓜发病率最低,仅为4.76%。     

Promoting the Use of Information and Communication Technologies (ICTs) for Agricultural Transformation in Sub-Saharan Africa: Implications for Policy

Information and communication technologies (ICTs) have the potential to reach many farmers with timely and accessible content. This article highlights the importance of ICTs in promoting agricultural transformation. It recommends the establishment of agricultural communication networks, which involve active participation of all stakeholders in agriculture and highlights the need for a participatory approach, the monitoring and evaluation of end users, and the integration of farmer knowledge and information needs into the content management system. Public institutions in agriculture should also be involved in developing a curriculum in ICTs for agricultural development and support ICT platforms to facilitate farmers’ access to quality agricultural information.     

Plant Alkaline Fusion Technique Followed by Colorimetric Procedure for the Detection and Quantification of Total Silicon in Ornamental Plants

Silicon (Si)–determination procedures currently available require expensive equipment and must be modified to assess Si concentrations in plant tissues. A Si-determination procedure referred to as the plant alkaline fusion technique, or PAFT, was developed to assess total Si concentrations, specifically in plant tissue. The procedure consists of dry-ashing the plant material, alkaline fusion, solubilization of the fusion cake, dilution, and colorimetric determination to quantify total Si content. The fusion technique for solubilizing plant Si can be performed using sodium hydroxide (NaOH), nickel crucibles, and Bunsen burners. Silicon concentrations of two National Institute of Standards and Technology (NIST) standard reference materials (SRM) [pine needles (SRM 1575) and peach leaves (SRM 1547)], a rice straw standard (LSU#5), an NIST soil standard (SRM 2709), and five ornamental plant species were all assessed using the PAFT procedure, and then these values were compared to two different inductively coupled plasma–optical emission spectroscopy (ICP-OES) procedures conducted by independent laboratories. The PAFT Si determination procedure typically reported the greatest value or was within 15% of the two ICP-OES procedures while costing significantly less than both ICP-OES procedures.     

Assessment of Nitrogen and Phosphorus Pathways at the Profile of Over-fertilised Alluvial Soils. Implications for Best Management Practices

Contrasting soil profiles (coarse-textured and fine-textured) treated with brilliant blue (BB) dye tracer, inorganic nitrogen (N) and phosphorus (P) concentrations along and between stained preferential flow pathways were examined for an irrigated and overfertilised maize monoculture system at the Mediterranean central Chile. The PO4-P concentrations were 2- to 10-fold higher in areas with BB than in areas without BB below 0.5-m soil depth in both soils. This elevated concentration was attributed to transport through cracks in fine-textured soil and finger flow in coarse-textured soil. The highest PO4-P value (13 mg kg^?1) was found in areas with BB at the fine-textured soil. There were no significant differences in inorganic N concentration between areas with and without BB for both soils, which suggest that the effects of preferential flow are less important for inorganic N forms. There was a strong significant (p?<?0.01) positive correlation between PO4-P and NH4-N concentrations in the fine-textured soil, and the amounts retained were clearly proportional to the clay content. Strategies for reducing N and P losses must be placed on good agronomic management of irrigated maize cropping system including accurate calculation of N and P fertiliser rates and establishment of suitable mitigation measures such as cover cropping.     

Removal of Benzene by the Indoor Plant/Substrate Microcosm and Implications for Air Quality

Water, Air, &; Soil Pollution - The quality of the indoor environment has become a major health consideration, since urban-dwellers spend 80-90% of their time indoors, where air pollution can be...     

Knowledge and attitudes of children of the Rupununi: Implications for conservation in Guyana

Knowledge and attitudes of children towards wildlife and the environment were assessed through questionnaires given to 366 children in 9 schools in southwest Guyana. Children’s responses revealed that they had a general knowledge of wildlife but knew few details about specific species. Respondents thought that wildlife was important but were nonetheless tolerant of several forms of environmental exploitation. Visits by conservation organizations, Conservation International and Foster Parrots, were shown to increase appreciation of wildlife and the need to set up more protected areas, but unless programmes were concentrated and sustained they had little effect on attitudes towards environmental utilization and exploitation. Experience of the natural world in terms of owning a domestic animal or pet, having visited a zoo, or being a member of a wildlife club had little impact on children’s knowledge of wildlife and did not change attitudes to utilization and exploitation. Surprisingly, Guyanese children did not have particularly positive views about classic flagship species, such as jaguars, giant anteaters and tapirs, when compared to other species. Our findings suggest that zoos, wildlife clubs and conservation organizations could enhance the dissemination of their message through making more frequent and sustained visits, imparting more detailed knowledge, and exposing children to the potential dangers of utilization and exploitation; also that conservation organizations should reassess their use of standard flagship species in South America.     

Distance to high-tide roosts constrains the use of foraging areas by dunlins: Implications for the management of estuarine wetlands

Shorebirds are declining all around the world, mostly due to deterioration of the estuarine habitats used in winter and migration. Estuaries cover small areas, so it is essential to guarantee that shorebirds can access all the tidal flats where they usually feed at low-tide.Studying use of space by dunlins (Calidris alpina) in the Tagus estuary (Portugal), we noted that lack of suitably located high-tide roosts can limit the access of shorebirds to feeding habitats. Density of dunlins on foraging areas declined significantly with distance to the nearest roost, and fewer than 20% individuals foraged more than 5 km from two roosts where they were dye-marked.So to permit full access to feeding areas it is important to maintain a network of suitably located high-tide roosts. We developed a GIS modelling methodology to evaluate the adequacy of existing roost networks, and to estimate the consequences of losing or creating new roosts. The methodology requires maps with the location of roosts and foraging habitats, and knowledge of the distances that birds are willing to fly to reach foraging areas. It quantifies the proportion of foraging areas close to the existing roosts and the average distance that birds have to fly to reach potential feeding sites.Applying this methodology to the Tagus estuary we concluded that lack of roosts probably explains why the intertidal flats in the north-west of the estuary are underused by shorebirds. A modelling exercise suggested that this gap could be eliminated by creating a roost in an old drained wetland area. We also modelled the impact of the loss of two roosts that are currently threatened. Without them almost half of the available feeding areas will be too far from roosts to be efficiently used by dunlins, and possibly by other shorebirds.     

Monitoring BTEX and Aldehydes in Car Exhaust from a Gasoline Engine During the Use of Different Chemical Cleaners by Solid Phase Microextraction-Gas Chromatography

All commercial gasoline fuels build up deposits on the spark plugs, injectors, oxygen sensors, catalytic converter, and inside the combustion chamber, which will lower the engine's performance and increase air pollution. As a result, fuel-based detergents have been developed to prevent and remove unwanted deposits. Unfortunately, many of the detergents use high amounts of aromatic solvents, which result in a greater risk of exposure to aromatic compounds like benzene. In this study, car exhaust was analyzed for benzene, toluene, ethylbenzene, and xylenes (BTEX), as well as formaldehyde and acetaldehyde during engine cleaning service using different chemical cleaners. A special device was designed for sampling from car exhaust using solid phase microextraction. The extracted compounds were analyzed using a gas chromatograph with flame ionization detector. The cleaning products were rated with regard to the amount of pollutants produced during the cleaning service.     

Social perceptions of the impacts and benefits of invasive alien species: Implications for management

Research on biological invasions has traditionally focused on the ecological component of invasive alien species, either without considering or by considering in a restricted way, the knowledge of the social component. An understanding of the human dimension of invasions is critical to effectively tackle the problems associated with invasive alien species. We distributed questionnaires to evaluate the social perceptions and attitudes of different stakeholder groups affected by invasive alien species in the Doñana social-ecological system (SW Spain). Our analysis served to characterize respondents based on their knowledge and perceptions of the impacts of invasive alien species, and the attitudes toward their introduction and eradication. Hierarchical cluster and principal component analyses identified five categories of respondents, and potential support of eradication programs was assessed using a contingent valuation approach. The five stakeholder groups differed in their degree of knowledge, perceptions, attitudes, and willingness to pay for eradication. The fact that different stakeholders have remarkably different perceptions about the impacts and benefits caused by invasive alien species, and different attitudes toward their introduction or eradication should be considered in any decision-making process regarding their management, particularly when developing appropriate educational and informative programs. Consultation with different stakeholders should also be encouraged from the onset of any decision-making process. In this way, trade-offs involved in IAS management are directly addressed and successful implementation of management practices is facilitated.     

Use of Stable Isotope Ratios for Evaluating Sulfur Sources and Losses at the Hubbard Brook Experimental Forest

Water, Air, &; Soil Pollution - Anthropogenic S emissions have been declining in eastern North America since the early 1970s. Declines in atmospheric S deposition have resulted in decreases in...     

Equilibrium Isotherm Studies for the Sorption of Divalent Metal Ions onto Peat: Copper,Nickel and Lead Single Component Systems

The sorption of three divalent metal ions — copper, nickel and lead — from aqueous solution onto peat in single component systems has been studied and the equilibrium isotherms determined. The experimental data have been analysed using the Langmuir, Freundlich, Redlich-Peterson, Toth, Temkin, Dubinin-Radushkevich and Sips isotherm models. In order to determine the best fit isotherm for each system, six error analysis methods were used to evaluate the data: the coefficient of determination, the sum of the errors squared, a hybrid error function, Marquardt's percent standard deviation, the average relative error and the sum of absolute errors. The error values demonstrated that the Sips equation provided the best model for the three sets of experimental data overall.     

Ethno-Practices and Adaptation Strategies for the Mitigation of Climate Change by Arable Crop Farmers in Osun State: Implications for Extension Policy Formulation in Nigeria

The study investigated methods used by arable crop farmers to mitigate climate change in Osun State, Nigeria. Data were collected with the aid of a structured interview schedule from 120 arable crop farmers selected from 24 communities. Age (b = ?.392; p < .05), household size (b = .190; p < .049), income (b = .182; p < .057), sources of information (b = .161; p < .105), and farm size (b = .258; p < .004) were significant with adaptation strategies. Strategies regularly employed included use of different planting dates (88.6%), multiple cropping (73%), and cover cropping (55%). The study concluded that arable crop farmers use sustainable methods to ameliorate climate change to the advantage of their production.     

Effects of Land Use and Wildfires on the Habitat Selection of Great Bustard (Otis tarda l.)—Implications for Species Conservation

Increasing agricultural activities have been shown to affect soil and vegetation changes leading to serious biodiversity declines throughout the world. These effects are amplified in dry grassland areas, where resulting changes in habitat structure affect threatened animals on long temporal scales. Great bustards (Otis tarda) inhabit open landscapes where fire and grazing have been a part of the natural disturbance regime since historical times. Even fire and grazing are hypothesized to be important factors in the lifecycle of the species, studies are still missing on disturbance‐related lekking distribution patterns of great bustards. We analyzed the importance of fires and grazing on the spatial distribution of lekking bustards controlling for habitat types, habitat diversity, distance from roads and social effects. Our standardized dataset spanned 31 years, being one of the largest datasets on bustard lekking. During the 31 years we observed 10 118 individuals at 639 observation points in Hortobágy National Park, East‐Hungary. One of the most important predictors for total number of birds and number of males was the area burnt in previous years. We found that increased habitat diversity had a positive effect on female numbers. Models fit on second‐ and third‐year burn data detected no substantial role of burning on lekking distribution. Our results suggest that introduction of a patch‐burning management system in lekking areas could increase the availability of optimal lek sites for bustards. As an effective management tool, we suggest applying patch‐burning annually in a spatially mosaic structure inside the area occupied by each sub‐population unit. Copyright © 2016 John Wiley & Sons, Ltd.