Sample records for subtropical no-till sandy

  1. Effects of No-Till on Yields as Influenced by Crop and Environmental Factors

    Energy Technology Data Exchange (ETDEWEB)

    Toliver, Dustin K.; Larson, James A.; Roberts, Roland K.; English, B.C.; De La Torre Ugarte, D. G.; West, Tristram O.


    Th is research evaluated diff erences in yields and associated downside risk from using no-till and tillage practices. Yields from 442 paired tillage experiments across the United States were evaluated with respect to six crops and environmental factors including geographic location, annual precipitation, soil texture, and time since conversion from tillage to no-till. Results indicated that mean yields for sorghum [Sorghum bicolor (L.) Moench] and wheat (Triticum aestivum L.) with no-till were greater than with tillage. In addition, no-till tended to produce similar or greater mean yields than tillage for crops grown on loamy soils in the Southern Seaboard and Mississippi Portal regions. A warmer and more humid climate and warmer soils in these regions relative to the Heartland, Basin and Range, and Fruitful Rim regions appear to favor no-till on loamy soils. With the exception of corn (Zea mays L.) and cotton (Gossypium hirsutum L.) in the Southern Seaboard region, no-till performed poorly on sandy soils. Crops grown in the Southern Seaboard were less likely to have lower no-till yields than tillage yields on loamy soils and thus had lower downside yield risk than other farm resource regions. Consistent with mean yield results, soybean [Glycine max (L.) Merr.] and wheat grown on sandy soils in the Southern Seaboard region using no-till had larger downside yield risks than when produced with no-till on loamy soils. Th e key fi ndings of this study support the hypothesis that soil and climate factors impact no-till yields relative to tillage yields and may be an important factor infl uencing risk and expected return and the adoption of the practice by farmers.

  2. Potential of carbon accumulation in no-till soils with intensive use and cover crops in southern Brazil. (United States)

    Amado, Telmo Jorge Carneiro; Bayer, Cimélio; Conceição, Paulo Cesar; Spagnollo, Evandro; de Campos, Ben-Hur Costa; da Veiga, Milton


    The area under no-till (NT) in Brazil reached 22 million ha in 2004-2005, of which approximately 45% was located in the southern states. From the 1970s to the mid-1980s, this region was a source of carbon dioxide to the atmosphere due to decrease of soil carbon (C) stocks and high consumption of fuel by intensive tillage. Since then, NT has partially restored the soil C lost and reduced the consumption of fossil fuels. To assess the potential of C accumulation in NT soils, four long-term experiments (7-19 yr) in subtropical soils (Paleudult, Paleudalf, and Hapludox) varying in soil texture (87-760 g kg(-1) of clay) in agroecologic southern Brazil zones (central region, northwest basaltic plateau in Rio Grande Sul, and west basaltic plateau in Santa Catarina) and with different cropping systems (soybean and maize) were investigated. The lability of soil organic matter (SOM) was calculated as the ratio of total organic carbon (TOC) to particulate organic carbon (POC), and the role of physical protection on stability of SOM was evaluated. In general, TOC and POC stocks in native grass correlated closely with clay content. Conversely, there was no clear effect of soil texture on C accumulation rates in NT soils, which ranged from 0.12 to 0.59 Mg ha(-1) yr(-1). The C accumulation was higher in NT than in conventional-till (CT) soils. The legume cover crops pigeon pea [Cajanus cajan (L.) Millsp] and velvet beans (Stizolobium cinereum Piper & Tracy) in NT maize cropping systems had the highest C accumulation rates (0.38-0.59 Mg ha(-1) yr(-1)). The intensive cropping systems also were effective in increasing the C accumulation rates in NT soils (0.25-0.34 Mg ha(-1) yr(-1)) when compared to the double-crop system used by farmers. These results stress the role of N fixation in improving the tropical and subtropical cropping systems. The physical protection of SOM within soil aggregates was an important mechanism of C accumulation in the sandy clay loam Paleudult under NT

  3. Integrating a complex rotation with no-till improves weed management in organic farming (United States)

    No-till practices are restoring and protecting soil health, and are considered critical for achieving sustainability of global agriculture. Organic producers in the United States would like to no-till, but are concerned about managing weeds without tillage. In conventional agriculture, no-till imp...

  4. Adaptability of Wheat Cultivars to a Late-Planted No-Till Fallow Production System

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    Arron H. Carter


    Full Text Available In Washington, over fifty percent of the wheat produced under rainfed conditions receives less than 300 mm of annual precipitation. Hence, a winter wheat-summer fallow cropping system has been adopted to obtain adequate moisture for winter wheat production. Current tilled fallow systems are exposed to significant soil degradation from wind and water erosion. As a result, late-planted no-till fallow systems are being evaluated to mitigate erosion concerns. The objective of this study was to evaluate current cultivars under late-planted no-till fallow systems to identify whether current breeding schemes in tilled fallow systems could select productive cultivars in late-planted no-till fallow systems. Thirty cultivars were planted in a split-plot design with fallow type as the main plot and genotype as the sub-plot. Fallow types evaluated were a tilled fallow system and a late planted no-till fallow system. Data were collected on heading date, plant height, grain volume weight, grain yield, and grain protein content. Analysis of variance was conducted on data across locations. Results were significant for all traits except for grain protein content. The late-planted no-till fallow system headed 16 days later was 5 cm shorter, yielded 36% less, and had a grain volume weight 3% less than the tilled fallow system. The lower yield and grain volume weight potential is hypothesized to be due to the 16 day delay in heading date leading to warmer temperatures during grain fill and a shorter duration. In order to breed wheat to be highly productive under a late-planted no-till fallow system, directly selecting in this system for early spring growth and earlier heading dates will be essential.

  5. No-till snap bean performance and weed response following rye and vetch cover crops (United States)

    Fall-planted cover crops offer many benefits including weed suppressive residues in spring sown crops when controlled and left on the soil surface. However, vegetable growers have been slow to adapt direct seeding (no-till) into cover crop residues. Field studies were conducted in 2009 and 2010 near...

  6. Functional and nutritional characteristics of soft wheat grown in no-till and conventional cropping systems (United States)

    The effects of no-till vs. conventional farming practices were evaluated on soft wheat functional and nutritional characteristics, including kernel physical properties, whole wheat composition, antioxidant activity and end-product quality. Soft white winter wheat cv. ORCF 102 was evaluated over a tw...

  7. Cover crop termination timing is critical in organic rotational no-till systems (United States)

    Cover crop-based rotational no-till enables organic farmers to reduce labor and build soil health. In these systems, cover crops are terminated with a roller-crimper and cash crops are direct-seeded into the mulch. A cropping system experiment was conducted at three locations in the Mid-Atlantic t...


    Conservation tillage systems that prevent soil erosion and maintain or increase soil carbon offer long-term benefits for producers in the inland Pacific Northwest (PNW) USA. Our objective was to compare conventional tillage and no-till for runoff and soil erosion. Two neighboring drainages in the 13...

  9. In Winter Wheat, No-Till Increases Mycorrhizal Colonization thus Reducing the Need for Nitrogen Fertilization

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    Julien Verzeaux


    Full Text Available Arbuscular mycorrhizal fungi (AMF play a major role in the uptake of nutrients by agricultural plants. Nevertheless, some agricultural practices can interrupt fungal-plant signaling and thus impede the establishment of the mycorrhizal symbiosis. A field experiment performed over a 5-year period demonstrated that both the absence of tillage and of nitrogen (N fertilization improved AMF colonization of wheat roots. Moreover, under no-till conditions, N uptake and aboveground biomass production did not vary significantly between N-fertilized and N-unfertilized plots. In contrast, both N uptake and above ground biomass were much lower when N fertilizer was not added during conventional tillage. This finding strongly suggests that for wheat, no-till farming is a sustainable agricultural system that allows a gradual reduction in N fertilizer use by promoting AMF functionality and at the same time increasing N uptake.

  10. Macroaggregation and soil organic carbon restoration in a highly weathered Brazilian Oxisol after two decades under no-till. (United States)

    de Oliveira Ferreira, Ademir; de Moraes Sá, João Carlos; Lal, Rattan; Tivet, Florent; Briedis, Clever; Inagaki, Thiago Massao; Gonçalves, Daniel Ruiz Potma; Romaniw, Jucimare


    Conclusions based on studies of the impacts of soil organic carbon (SOC) fractions and soil texture on macroaggregation and SOC stabilization in long-term (>20years) no-till (NT) fields remain debatable. This study was based on the hypothesis that the amount and frequency of biomass-C input associated with NT can be a pathway to formation of macroaggregates and to SOC buildup. The objectives were to: 1) assess the macroaggregate distribution (proportional mass, class mass) and the SOC and particulate organic carbon (POC) stocks of extra-large (8-19mm), large (2-8mm) and small (0.25-2mm) macroaggregate size classes managed for two decades by NT, and 2) assess the recovery of SOC stocks in extra-large macroaggregates compared to adjacent native vegetation (Andropogon sp., Aristida sp., Paspalum sp., and Panicum sp.). The crop rotation systems were: soybean (Glycine max L.), maize (Zea mays L.) and beans (Phaseolus vulgaris L.) in summer; and black oat (Avena strigosa Schreb), white oat (Avena sativa), vetch (Vicia sativa L.), black oat.+vetch (Avena strigosa Schreb+vetch) and wheat (Triticum aestivum L.) in winter. The experimental was laid out as 2×2 randomized block factorial with 12 replicates of a NT experiment established in 1997 on two highly weathered Oxisols. The factors comprised of: (a) two soil textural types: clay loam and sandy clay, and (b) two sampling depths: 0-5 and 5-20cm. The three classes of macroaggregates were obtained by wet sieving, and the SOC content was determined by the dry combustion method. The extra-large macroaggregate classes in 0-20cm depth for sandy clay (SdC) and clay loam (CL) Oxisol represented 75.2 and 72.4% of proportional mass, respectively. The SOC and POC stocks among macroaggregate classes in 0-5 and 5-20cm depths decreased in the order: 8-19mm>2-8mm ≈ 0.25-2mm. The SdC plots under soybean/maize at 3:1 ratio recovered 58.3%, while those at 1:1 ratio (high maize frequency) in CL recovered 73.1% of SOC stock in the extra

  11. Subsurface application of poultry litter in pasture and no-till soils. (United States)

    Pote, D H; Way, T R; Kleinman, P J A; Moore, P A; Meisinger, J J; Sistani, K R; Saporito, L S; Allen, A L; Feyereisen, G W


    Poultry litter provides a rich nutrient source for crops, but the usual practice of surface-applying litter can degrade water quality by allowing nutrients to be transported from fields in surface runoff while much of the ammonia (NH3)-N escapes into the atmosphere. Our goal was to improve on conventional titter application methods to decrease associated nutrient losses to air and water while increasing soil productivity. We developed and tested a knifing technique to directly apply dry poultry litter beneath the surface of pastures. Results showed that subsurface litter application decreased NH3-N volatilization and nutrient losses in runoff more than 90% (compared with surface-applied litter) to levels statistically as low as those from control (no litter) plots. Given this success, two advanced tractor-drawn prototypes were developed to subsurface apply poultry litter in field research. The two prototypes have been tested in pasture and no-till experiments and are both effective in improving nutrient-use efficiency compared with surface-applied litter, increasing crop yields (possibly by retaining more nitrogen in the soil), and decreasing nutrient losses, often to near background (control plot) levels. A paired-watershed study showed that cumulative phosphorus losses in runoff from continuously grazed perennial pastures were decreased by 55% over a 3-yr period if the annual poultry litter applications were subsurface applied rather than surface broadcast. Results highlight opportunities and challenges for commercial adoption of subsurface poultry litter application in pasture and no-till systems.

  12. Ammonia volatilization from nitrogen fertilizers in no-till wheat and maize in southern Brazil

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    Fernando Viero


    Full Text Available Crop residues on the soil surface of no-till systems can intensify ammonia volatilization from N fertilizers applied to cereal crops. This study assessed the magnitude of N losses through ammonia volatilization from urea applied to no-till winter (wheat and summer crops (maize on a Typic Hapludox in the south-central region of Paraná, southern Brazil. In addition, the potential of alternative N sources (urea with urease inhibitor, liquid fertilizer, ammonium nitrate and ammonium sulfate and different urea managements (fertilizer applied in the morning or afternoon were evaluated. Two experiments with maize and wheat were carried out for two years, arranged in a randomized block design with four replications. Nitrogen volatilization losses were assessed with a semi-open static collector until 21 days after fertilization. In winter, the losses were low (<5.5 % of applied N for all N sources, which were not distinguishable, due to the low temperatures. In the summer, volatilization rates from urea were higher than in the winter, but did not exceed 15 % of applied N. The main factor decreasing N losses in the summer was the occurrence of rainfall in the first five days after fertilization. Urea with urease inhibitor, nitrate and ammonium sulfate were efficient to decrease ammonia volatilization in maize, whereas the application time (morning or afternoon had no influence.

  13. No-till systems on the Chequen Farm in Chile: A success story in bringing practice and science together

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    D. Reicosky


    Full Text Available No-till cropping systems provide an opportunity to protect the soil from erosion, while contemporaneously maintaining high yields and contributing to global food security. The historical aspects and the remarkable development of no-till systems on the Chequen Farm in Chile are reviewed. The adoption of no-till over the last 40 years has been a major turning point in reducing the devastating effects of soil erosion and a model for the evolution of sustainable crop production in highly erodible terrain in other parts of the world. The process of adoption of no-till systems in severely eroded foothills of Chile is described, as well as the environmental benefits and the sustainability of the system. The practical aspects of these developments are supported by scientific literature where appropriate, illustrating the value and coincident knowledge gained when combining analogue observations and information with scientific principles.

  14. Predacious activity of Ants (Hymenoptera: Formicidae in conventional and in No-till agriculture systems

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    Denise Lange


    Full Text Available This study had the objective of assessing the differences in foraging activity of the predacious ants between two areas, one conventional and other with no-till agriculture systems. The research was conducted in two contiguous 1.5 ha plots in Dourados MS, Brazil, from February 2001 to December 2003. Each plot received 750 baits (Nasutitermes termites, 425 at daylight and 325 at night. The termites were placed on the filter paper, on the ground, and ant attack was monitored for 15 min, until removed. Sixteen ant species were found in the no-till system and nine in the conventional system. Baits removed from no-till were significantly higher than the conventional plots and were influenced by the sampling time, at day or night. The seasons of the year did not significantly explain the variations in the structure of the predacious ant communities in neither of the systems. The significant differences at foraging activity and ant richness between the areas indicated that the no-tillage system could improve environmental quality of the cropping and therefore, became an important tool for the integrated pest management programs.O objetivo do trabalho foi avaliar se a atividade de forrageamento de formigas predadoras em agroecossistemas varia entre duas áreas, uma com sistema de cultivo direto e outra com cultivo convencional. A pesquisa foi realizada em Dourados, MS, de fevereiro de 2001 a dezembro de 2003 em duas áreas contíguas de 1,5 ha cada. Como isca utilizou-se cupins do gênero Nasutitermes. Em cada área foram colocadas 750 iscas, sendo 425 durante o dia e 325 à noite. Cada cupim permanecia exposto sobre o solo por 15 minutos, ou até ser atacado. Foram encontradas 16 espécies de formigas no plantio direto e nove no convencional. A proporção de iscas retiradas por formigas no plantio direto (167 de 750 e convencional (97 de 750 dependeu do turno de amostragem. Nos dois turnos a proporção de iscas removidas por formigas foi

  15. Changes of Soil Aggregate C Isotopes in No-Till Corn Following Bromegrass. (United States)

    Follett, R. F.; Varvel, G.; Vogel, K. P.


    This field study is near Ithaca, Nebraska, USA (lat. 41.151, long. 96.401) on a Filbert silt loam (fine, smectitic, mesic Vertic Argialboll). The site was in bromegrass since 1986. Corn was no-till seeded into the bromegrass sod in spring 1999. A randomized complete block design with three replicates was used. No-till corn was the main treatment with nitrogen (N) as subplots. N was broadcast at the start of each growing season at 60 or 120 kg N/ha as NH4NO3. Total biomass was measured by weighing 4.4 m of row in each plot. Soil samples were obtained in May 1999 (baseline sampling), Sept 1999, June 2000, Oct 2000, Sept 2001, Nov 2002, Sept 2003, and Oct 2005 from pre-selected areas by removal of plant material from the soil surface and removing the 0-5, 5- 10, and at 4 of the 8 harvests also sampling the 10-30 cm depths with a flat-bladed shovel. Soil bulk densities were determined on clods from each layer. The moist soil was passed through an 8 mm sieve before air drying and storing. Aggregate size fractions were obtained with a Yoder wet-aggregate method. Soil size fractions obtained were > 2, 1, 0.5, 0.25, 0.125, 0.045 and < 0.045 mm. Detritus was floated to the surface and skimmed off for transfer to a separate container. Aggregates were dried at 55°C, weighed, ground, and analyzed for total C and N and 13C:12C isotope ratio. Because soil organic carbon (SOC) was labeled with the bromegrass (C3 plant) isotope signature, then during the 77 months of this experiment the re-labeling of each fraction and the total SOC with the corn (C4 plant) isotope signature and the amounts of SOC lost from aggregate size fractions with conversion of the bromegrass sod to no-till corn was measured. During 6.5 years, total SOC decreased from 21.1, 17.0, and 55.8 t/ha in the 0-5, 5-10, and 10-30 cm depths to 20.1, 16.7, and 55.5 t/ha, respectively. However the SOC in the < 2, 0.5-2, and < 0.5 mm fractions of the 0 - 5 cm depth changed from 62, 21, and 16 % of the total SOC at the

  16. Soil macrofauna communities under plant cover in a no-till system in Thailand

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    Phakphoom Tantachasatid


    Full Text Available The impact of no-till cropping systems with plant cover on soil macrofauna communities was assessed according to their abundance and biomass. The study was carried out in northeastern Thailand under a conventional cropping system (plow-based tillage, no-till cropping systems with plant cover (Brachiaria ruziziensis, Stylosanthes guianensis, S. guianensis associated with B. ruziziensis, rice straw and under a natural dipterocarp forest. Soil macrofauna populations were sampled in 2007 (June and October during the rainy season and at a beginning of the dry season, respectively. The results revealed that in the short term, the biological compartment responded quickly to the presence of plant cover, as shown by a significant increase in soil macrofauna abundance and total biomass. The highest mean total abundance (MTA of 4224 individuals/m2 at the end of planting period (October 2007 was observed under S. guianensis cover and also the highest mean total soil macrofauna biomass (MTB of 14.63 g/m2 was observed in the forest system in the same period. However, in the system of cultivation, the highest MTB of 11.33 g/m2 was observed under S. guianensis cover. Moreover, the change rate of soil macrofauna MTA was the highest under S. guianensis cover (+751.61% and the change rate of soil macrofauna MTB revealed that this change rate was highest in forest (+430.07%. However, in the other systems of cultivation, the highest change rate of MTB was under S. guianensis cover (+12.96%.

  17. No-till and conservation agriculture in the United States: An example from the David Brandt farm, Carroll, Ohio

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    R. Islam


    Another early adopter, Bill Richards, from Circleville, Ohio, also became a national leader and promoter of no-till farming. He served as head of the United States Department of Agriculture's Natural Resources Conservation Service in the early 1990s and instituted a program that led to rapid expansion of no-till. He advises that farmers who follow conservation agriculture principles need to be more proactive, from local level to national levels, to influence policy decisions that can lead to robust improvement in soil health.

  18. Glyphosate Dissipation in Different Soils Under No-Till and Conventional Till (United States)

    Okada, Elena; Costa, Jose Luis; Francisco, Bedmar


    Glyphosate is the most used herbicide in Argentina, accounting for 62% of the commercialized pesticides in the market. It is used as a weed controller in chemical fallow under no-till systems, and it is also applied in various genetically modified crops (e.g. soybean, corn, cotton). Though it has a high solubility in water, it tends to adsorb and accumulate in agricultural soils. The description of glyphosate biodegradation in soils with a long term history under agricultural practices is of interest. The main objectives of this work were to compare the dissipation of glyphosate and the accumulation of its metabolite aminomethylphosphonic acid (AMPA) over time in three soils from Argentina. The studied soils belong to areas of high agronomic land use and different edaphoclimatic conditions, situated in Manfredi (MAN), Pergamino (PER) and Paraná (PAR). Soil samples were taken from long-term field trials with a history of more than 16 years under no-till and conventional tillage management. To study glyphosate dissipation in soil under controlled laboratory conditions, 400 g of dry soil sample were placed in 1.5 L flasks. A dose corresponding to 6 L ha-1 of commercial glyphosate ATANOR II® (35.6 % a.i.) was applied on day 0. The dose applied was equivalent to a final concentration in soil of 4000 μg Kg-1 of active ingredient. The moisture of the soil samples was kept at 60 % of the field capacity. Samples were incubated in the dark at a constant temperature of 22°C ± 1°C. A sub-sample of 5 g was taken from each flask at day 0 (after application), 1, 3, 7, 15, 20, 28, 44 and 62. Glyphosate and AMPA in soil samples was extracted with a strong basic solution (100 mM Na2B4O7•10H2O/ 100 mM K3PO4, pH=9) and then derivitazed with FMOC-Cl. Detection and quantification of the compounds was performed by ultra-performance liquid chromatography coupled with a mass spectrometer (UPLC MS/MS). The results showed that forty percent of the applied glyphosate was degraded

  19. Release of Phosphorus Forms from Cover Crop Residues in Agroecological No-Till Onion Production

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    Rodolfo Assis de Oliveira

    Full Text Available ABSTRACT Cover crops grown alone or in association can take up different amounts of phosphorus (P from the soil and accumulate it in different P-forms in plant tissue. Cover crop residues with a higher content of readily decomposed forms may release P more quickly for the next onion crop. The aim of this study was to evaluate the release of P forms from residues of single and mixed cover crops in agroecological no-till onion (Allium cepa L. production. The experiment was conducted in Ituporanga, Santa Catarina (SC, Brazil, in an Inceptisol, with the following treatments: weeds, black oat (Avena sativa L., rye (Secale cereale L., oilseed radish (Raphanus sativus L., oilseed radish + black oat, and oilseed radish + rye. Cover crops were sown in April 2013. In July 2013, plant shoots were cut close to the soil surface and part of the material was placed in litterbags. The bags were placed on the soil surface and residues were collected at 0, 15, and 45 days after deposition (DAD. Residues were dried and ground and P in the plant tissue was determined through chemical fractionation. The release of P contained in the tissue of cover crops depends not only on total P content in the tissue, but also on the accumulation of P forms and the quality of the residue in decomposition. The highest accumulation of P in cover crops occurred in the soluble inorganic P fraction, which is the fraction of fastest release in plants. Black oat had the highest initial release rate of soluble inorganic P, which became equal to the release rate of other cover crop residues at 45 DAD. Weeds released only half the amount of soluble inorganic P in the same period, despite accumulating a considerable amount of P in their biomass. The mixtures of oilseed radish + rye and oilseed radish + black oat showed higher release of P associated with RNA at 45 DAD in comparison to the single treatments.

  20. Nitrogen source and placement effects on soil nitrous oxide emissions from no-till corn. (United States)

    Halvorson, Ardell D; Del Grosso, Stephen J


    A nitrogen (N) source comparison study was conducted to further evaluate the effects of inorganic N source and placement on growing-season and non-crop period soil nitrous oxide (NO). Commercially available controlled-release N fertilizers were evaluated for their potential to reduce NO emissions from a clay loam soil compared with conventionally used granular urea and urea-ammonium nitrate (UAN) fertilizers in an irrigated no-till (NT) corn ( L.) production system. Controlled-release N fertilizers evaluated were: a polymer-coated urea (ESN), stabilized urea (SuperU), and UAN+AgrotainPlus (SuperU and AgrotainPlus contain nitrification and urease inhibitors). Each N source was surface band applied (202 kg N ha) near the corn row at emergence and watered into the soil the next day. Subsurface banded ESN (ESNssb) and check (no N applied) treatments were included. Nitrous oxide fluxes were measured during two growing seasons and after harvest using static, vented chambers. All N sources had significantly lower growing-season NO emissions than granular urea (0.7% of applied N), with UAN+AgrotainPlus (0.2% of applied N) and ESN (0.3% of applied N) having lower emissions than UAN (0.4% of applied N). Similar trends were observed when expressing NO emissions on a grain yield and N uptake basis. Corn grain yields were not different among N sources but were greater than the check. Selection of N fertilizer source can be a mitigation practice for reducing NO emissions in NT, irrigated corn in semiarid areas. In our study, UAN+AgrotainPlus consistently had the lowest level of NO emissions with no yield loss. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  1. Nitrogen source effects on nitrous oxide emissions from irrigated no-till corn. (United States)

    Halvorson, Ardell D; Del Grosso, Stephen J; Francesco, Alluvione


    Nitrogen fertilization is essential for optimizing crop yields; however, it may potentially increase nitrous oxide (N2O) emissions. The study objective was to assess the ability of commercially available enhanced-efficiency N fertilizers to reduce N2O emissions following their application in comparison with conventional dry granular urea and liquid urea-ammonium nitrate (UAN) fertilizers in an irrigated no-till (NT) corn (Zea mays L.) production system. Four enhanced-efficiency fertilizers were evaluated: two polymer-coated urea products (ESN and Duration III) and two fertilizers containing nitrification and urease inhibitors (SuperU and UAN+AgrotainPlus). Nitrous oxide fluxes were measured during two growing seasons using static, vented chambers and a gas chromatograph analyzer. Enhanced-efficiency fertilizers significantly reduced growing-season N2O-N emissions in comparison with urea, including UAN. SuperU and UAN+AgrotainPlus had significantly lower N2O-N emissions than UAN. Compared with urea, SuperU reduced N2O-N emissions 48%, ESN 34%, Duration III 31%, UAN 27%, and UAN+AgrotainPlus 53% averaged over 2 yr. Compared with UAN, UAN+AgrotainPlus reduced N2O emissions 35% and SuperU 29% averaged over 2 yr. The N2O-N loss as a percentage of N applied was 0.3% for urea, with all other N sources having significantly lower losses. Grain production was not reduced by the use of alternative N sources. This work shows that enhanced-efficiency N fertilizers can potentially reduce N2O-N emissions without affecting yields from irrigated NT corn systems in the semiarid central Great Plains.

  2. Allelopathic influence of a wheat or rye cover crop on growth and yield of no-till cotton (United States)

    TECHNICAL ABSTRACT No-till planting cotton into small grain cover crops has many benefits including reducing soil erosion and allelopathic suppression of weeds. It is suggested that the potentials of allelopathy on cotton plants. Nevertheless, little is known about the actual effects of alleloche...

  3. Influence of cover crops on arthropods, free-living nematodes, and yield in a succeeding no-till soybean crop (United States)

    Production practices that incorporate fall-planted cover crops into no-till agronomic crop rotations have become increasingly popular across the Northeastern United States for weed suppression and enhancing environmental stewardship. Field experiments were conducted in 2011 and 2012 to investigate e...

  4. PRACT (Prototyping Rotation and Association with Cover crop and no Till) - a tool for designing conservation agriculture systems

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    Naudin, K.; Husson, M.O.; Scopel, E.; Auzoux, S.; Giller, K.E.


    Moving to more agroecological cropping systems implies deep changes in the organization of cropping systems. We propose a method for formalizing the process of innovating cropping system prototype design using a tool called PRACT (Prototyping Rotation and Association with Cover crop and no Till)

  5. Forces and straw cutting performance of double disc furrow opener in no-till paddy soil.

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    Fiaz Ahmad

    Full Text Available Conservation tillage is an energy efficient and low cost tillage system to improve soil environment compared with conventional tillage systems. However, the rice residue management becomes an "impossible to achieve" task due to high soil moisture content at harvest time and the thickness of rice straw. Disc type furrow openers are used for both seed drilling as well as straw cutting during no tillage sowing. A study was conducted to evaluate the draft requirement and straw cutting performances of different sized furrow openers in no-till paddy soil conditions. Double disc furrow opener was tested on an in-field traction bench for three working depths, i.e. 30, 60 and 90 mm, and three forwarding speeds, i.e. 0.1, 0.2 and 0.3 m/s. The draft and vertical forces on the disc were recorded with load cells. These sensors were connected to a data acquisition system developed with hardware and software. The results revealed that the size of the furrow opener, operating depth and the forwarding speed had significant effects (P<0.05 on the horizontal and vertical forces, and the straw cutting performance. Mean values of the draft were 648.9, 737.2 and 784.6 N for the opener with diameters of 330, 450 and 600 mm respectively, and the vertical forces for similar openers were 904.7, 1553.9 and 1620.4 N, respectively. Furthermore, the mean straw cutting efficiencies for the double disc opener with diameters of 330, 450 and 600 mm were 39.36, 78.47 and 65.46%, respectively. The opener with 450 mm diameter provided higher straw cutting efficiency as compared to 600 mm diameter disc, while lowest straw cutting efficiency was observed with 330 mm diameter disc. The 450 mm diameter opener provided the highest straw cutting efficiency (88.6% at 90 mm working depth and expressed optimum performance compared with other furrow openers.

  6. The Influence of No-Till, Conventional Tillage and Nitrogen Fertilization on Physico-Chemical and Biological Indicators After Three Years of Monoculture Barley

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    Cristina Menta


    Full Text Available An experimental trial was carried out over three years at Cavacurta (Po valley, Italy on continuous barley. The soil was a coarse-loamy over sandy, mixed, mesic Fluventic Ustochrept. The experimental design was a split-plot with four replicates; the main factor was the soil management system (conventional tillage, CT, and no-tillage, NT, while the secondary factor was the nitrogen fertilization (N0 = 0, N1 = 50 and N2 = 90 kg N ha-1 year-1. At the end of the third year soil samples were taken in all plots at four depths (0-5, 5-10, 10-15 and 15-20 cm. For these samples, pH, organic matter, total N, available P and cation exchange capacity were determined. On the contrary, water aggregate stability was determined for a single layer (0-20 cm depth, excluding the N1 level of fertilization. The biological indicator, QBS-ar index, was studied only in the layer 0-10 cm. Statistical analysis shows that no-till positively influenced all the indices except for CEC and QBS-ar. N fertilization had significant effects on CEC only; in the upper layer, the value in N2 subplots was of approx. 1 cmol+ kg-1 higher than in N0 and N1 subplots. There was no significant interaction for any of the indices. As regards only the 0-20 cm layer, the most important results are as follows. The organic matter content in NT plots was significantly higher than in CT plots (32.6 vs 29.8 g kg-1, as was the total N (2.11 vs 1.97 g kg-1. No-till also had a very clear effect on the Olsen-P (12.3 vs 9.3 mg kg-1. The most remarkable result was found for the water aggregate stability: for NT plots the value was 246% higher than for CT plots (34.3 vs 9.9%. As regards the microarthropod community, the value of the QBS-ar index was between 90 and 126, a typical range for soil under barley.

  7. Ammonia volatilization from enhanced-efficiency urea on no-till maize in brazilian cerrado with improved soil fertility


    Eduardo Lopes Cancellier; Douglas Ramos Guelfi Silva; Valdemar Faquin; Bruno de Almeida Gonçalves; Leandro Lopes Cancellier; Carlos Roberto Spehar


    ABSTRACT High nitrogen losses by ammonia volatilization are expected when urea is used as the source of N. The use of controlled-release urea and urease inhibitors are possible strategies to reduce such losses and increase nitrogen use efficiency. This study aimed to evaluate nitrogen losses by ammonia volatilization from stabilized, slow and controlled release urea and its absorption by maize grown under no-till in an improved Cerrado soil. Four N sources were used: conventional urea, urea +...

  8. Assessment of soil physical attributes at sowing row and inter-row under no-till system

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    Julius Blum

    Full Text Available In no-till systems, two different soil conditions are created during the sowing operation: row and inter-row positions. The objectives of this study were to evaluate, using static and dynamic soil attributes, the influence of no-till sowing operation on creating better physical environment for soybean crop growth. A field transect with clay content ranging from 150 to 400 g kg-1 was selected in Ponta Grossa, Paraná State, Brazil, from a Typic Hapludox that has been cultivated under no-till system for 16 years. After soybean harvest, 68 undisturbed soil samples were collected at both sowing row and inter-row positions. The following soil properties were evaluated: saturated hydraulic conductivity, air permeability, bulk density, total porosity, soil moisture at field capacity, texture, and total organic carbon. Multiple regressions among dynamic and static soil properties were fitted, and differences between sowing row and inter-rows were tested by paired t test. Saturated hydraulic conductivity and air permeability were positively correlated with macroporosity (r = 0.75 and 0.74, respectively; p<0.001. Total porosity, bulk density, air permeability, and macroporosity were position-dependent. In general, soil physical quality was higher at row position due to lower bulk density and higher total porosity, hydraulic conductivity, air permeability and macroporosity.

  9. Stabilization of soil hydraulic properties under a long term no-till system

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    Luis Alberto Lozano


    Full Text Available The area under the no-tillage system (NT has been increasing over the last few years. Some authors indicate that stabilization of soil physical properties is reached after some years under NT while other authors debate this. The objective of this study was to determine the effect of the last crop in the rotation sequence (1st year: maize, 2nd year: soybean, 3rd year: wheat/soybean on soil pore configuration and hydraulic properties in two different soils (site 1: loam, site 2: sandy loam from the Argentinean Pampas region under long-term NT treatments in order to determine if stabilization of soil physical properties is reached apart from a specific time in the crop sequence. In addition, we compared two procedures for evaluating water-conducting macroporosities, and evaluated the efficiency of the pedotransfer function ROSETTA in estimating the parameters of the van Genuchten-Mualem (VGM model in these soils. Soil pore configuration and hydraulic properties were not stable and changed according to the crop sequence and the last crop grown in both sites. For both sites, saturated hydraulic conductivity, K0, water-conducting macroporosity, εma, and flow-weighted mean pore radius, R0ma, increased from the 1st to the 2nd year of the crop sequence, and this was attributed to the creation of water-conducting macropores by the maize roots. The VGM model adequately described the water retention curve (WRC for these soils, but not the hydraulic conductivity (K vs tension (h curve. The ROSETTA function failed in the estimation of these parameters. In summary, mean values of K0 ranged from 0.74 to 3.88 cm h-1. In studies on NT effects on soil physical properties, the crop effect must be considered.

  10. Simulating the impact of no-till systems on field water fluxes and maize productivity under semi-arid conditions (United States)

    Mupangwa, W.; Jewitt, G. P. W.

    Crop output from the smallholder farming sector in sub-Saharan Africa is trailing population growth leading to widespread household food insecurity. It is therefore imperative that crop production in semi-arid areas be improved in order to meet the food demand of the ever increasing human population. No-till farming practices have the potential to increase crop productivity in smallholder production systems of sub-Saharan Africa, but rarely do because of the constraints experienced by these farmers. One of the most significant of these is the consumption of mulch by livestock. In the absence of long term on-farm assessment of the no-till system under smallholder conditions, simulation modelling is a tool that provides an insight into the potential benefits and can highlight shortcomings of the system under existing soil, climatic and socio-economic conditions. Thus, this study was designed to better understand the long term impact of no-till system without mulch cover on field water fluxes and maize productivity under a highly variable rainfall pattern typical of semi-arid South Africa. The simulated on-farm experiment consisted of two tillage treatments namely oxen-drawn conventional ploughing (CT) and ripping (NT). The APSIM model was applied for a 95 year period after first being calibrated and validated using measured runoff and maize yield data. The predicted results showed significantly higher surface runoff from the conventional system compared to the no-till system. Predicted deep drainage losses were higher from the NT system compared to the CT system regardless of the rainfall pattern. However, the APSIM model predicted 62% of the annual rainfall being lost through soil evaporation from both tillage systems. The predicted yields from the two systems were within 50 kg ha -1 difference in 74% of the years used in the simulation. In only 9% of the years, the model predicted higher grain yield in the NT system compared to the CT system. It is suggested that

  11. Long-term no-till: A major driver of fungal communities in dryland wheat cropping systems.

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    Dipak Sharma-Poudyal

    Full Text Available In the dryland Pacific Northwest wheat cropping systems, no-till is becoming more prevalent as a way to reduce soil erosion and fuel inputs. Tillage can have a profound effect on microbial communities and soilborne fungal pathogens, such as Rhizoctonia. We compared the fungal communities in long-term no-till (NT plots adjacent to conventionally tilled (CT plots, over three years at two locations in Washington state and one location in Idaho, US. We used pyrosequencing of the fungal ITS gene and identified 422 OTUs after rarefication. Fungal richness was higher in NT compared to CT, in two of the locations. Humicola nigrescens, Cryptococcus terreus, Cadophora spp. Hydnodontaceae spp., and Exophiala spp. were more abundant in NT, while species of Glarea, Coniochaetales, Mycosphaerella tassiana, Cryptococcus bhutanensis, Chaetomium perlucidum, and Ulocladium chartarum were more abundant in CT in most locations. Other abundant groups that did not show any trends were Fusarium, Mortierella, Penicillium, Aspergillus, and Macroventuria. Plant pathogens such as Rhizoctonia (Ceratobasidiaceae were not abundant enough to see tillage differences, but Microdochium bolleyi, a weak root pathogen, was more abundant in NT. Our results suggest that NT fungi are better adapted at utilizing intact, decaying roots as a food source and may exist as root endophytes. CT fungi can utilize mature plant residues that are turned into the soil with tillage as pioneer colonizers, and then produce large numbers of conidia. But a larger proportion of the fungal community is not affected by tillage and may be niche generalists.


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    Full Text Available The replacement of natural vegetation by crop systems directly impacts the soil organic matter fractions. The objective of this study was to evaluate the total organic carbon (TOC and nitrogen (TN contents in different fractions of the soil organic matter (SOM of an Oxisol of the Brazilian semiarid region under different irrigated crops and different soil management systems. Seven treatments were evaluated, which consisted of two soil management systems (no - till and conventional tillage and three crops (maize, sunflower and sorghum, using as reference the soil under a native forest (NF. The summer crops preceded common bean crops in the autumn - winter. The total organic carbon content, total nitrogen, carbon content in humic substances and their constituents (fulvic acids, humic acids and humin and labile, non - labile and water - soluble carbon contents were evaluated two years and three months after the experiment implementation to determine the carbon lability (L lability index (LI, partitioning index (CPI and management index (CMI. The greatest carbon, nitrogen and organic matter contents in the soil surface layer (0.00 - 0.05 m were found in crops under no - till system (NTS, especially maize. The crops under NTS presented greater carbon content in humic substances than the conventional tillage system (CTS ones in the layer 0.05 - 0.10 m. The crops under NTS presented greater sustainability in the Brazilian semiarid region compared with those under CTS, as shown by their higher CMI in the soil surface layer.

  13. Influence of nitrogen fertilization and green manure on the economic feasibility of no-tilled wheat in the Cerrado

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    Douglas de Castilho Gitti


    Full Text Available The search for higher profitability in wheat crop with cost reduction technologies that may promote sustainability is an important matter in Brazilian agriculture. This study evaluated the profitability of no-tilled wheat, reducing nitrogen topdressing doses with the cultivation of green manure before the wheat crop. The experiment was carried out in Selvíria (MS, Brazil, in 2009/10. The experiment was arranged in a randomized block design with 36 treatments in splitplots and four replicates. The plots were formed by six types of green manure: Cajanus cajan L. BRS Mandarin, Crotalaria juncea L., Pennisetum americanum L. BRS 1501, fallow area and mixed cropping of Pennisetum americanum L. + Cajanus cajan L. and Pennisetum americanum L. + crotalaria which provided straw for no-tilled wheat in the winter, following the rice crop in the summer. The subplots were formed by six levels of topdressing nitrogen (0, 25, 50, 75, 100 and 125 kg N ha-1 using urea as a nitrogen source. The wheat grown after green manure in the previous winter crop, with no nitrogen topdressing and a rate of 25 kg ha-1 N, had more frequently production costs above the gross income. Wheat production cost after the mixed cropping Pennisetum americanum L. + Cajanus cajan L. and Pennisetum americanum L. + Crotalaria juncea L. from the previous winter crop, combined with nitrogen rates of 50 and 75 kg N ha-1, provided better profitability compared with the other green manures evaluated.

  14. Wheat Cultivar Performance and Stability between No-Till and Conventional Tillage Systems in the Pacific Northwest of the United States

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    Arron H. Carter


    Full Text Available In Washington, over fifty percent of the wheat produced under rainfed conditions receives less than 300 mm of annual precipitation. Hence, a winter wheat-summer fallow cropping system has been established to obtain adequate moisture for winter wheat production. Current tilled fallow systems receive significant soil erosion through both wind and water. As a result, no-till chemical fallow systems are being adopted to mitigate erosion concerns. The objective of this study was to evaluate current Pacific Northwest cultivars under no-till chemical fallow and tilled fallow systems to identify cultivars adapted to a late-planted no-till system. Twenty-one cultivars were planted in a split-plot design with fallow type as the main plot and genotype as the sub-plot. Four replications were planted at two locations over three years. Data was collected on heading date, grain yield and grain volume weight. Analysis of variance was conducted on data from each year and location. Results were significant for all traits. Cultivars in the late-planted no-till system yielded an average of 39% less than the tilled fallow system. It is evident that cultivars vary in their adaptability and yield stability across production systems. Chukar and Eltan displayed the highest levels of yield stability, and growers who wish to plant winter wheat in a late-planted no-till system may benefit from choosing these cultivars.

  15. Phosphorus and potassium cycling in a long-term no-till integrated soybean-beef cattle production system under different grazing intensities in subtropics (United States)

    Long-term crop-livestock integration enables constant and high nutrient cycling because animal, pasture and crop residues release nutrients at different rates. Therefore, appropriate management of these systems is needed to maximize the benefits of nutrient cycling. The objective of this study was t...

  16. 17beta-Estradiol and testosterone in drainage and runoff from poultry litter applications to tilled and no-till crop land under irrigation. (United States)

    Jenkins, Michael B; Endale, Dinku M; Schomberg, Harry H; Hartel, Peter G; Cabrera, Miguel L


    Thirteen million [corrected] metric tons of poultry litter are produced annually by poultry producers in the U.S. Poultry litter contains the sex hormones estradiol and testosterone, endocrine disruptors that have been detected in surface waters. The objective of this study was to evaluate the potential impact of poultry litter applications on estradiol and testosterone concentrations in subsurface drainage and surface runoff in irrigated crop land under no-till and conventional-till management. We conducted an irrigation study in fall of 2001 and spring of 2002. Four treatments, no-till plus poultry litter, conventional-till plus poultry litter, no-till plus conventional fertilizer, and conventional-till plus conventional fertilizer, were evaluated. Flow-weighted concentration and load ha(-1) of the two hormones were measured in drainage and runoff. Soil concentrations of estradiol and testosterone were measured. Based on comparisons to the conventional fertilizer (and control) treatments, poultry litter did not add to the flow-weighted concentration or load ha(-1) of either estradiol or testosterone in subsurface drainage or surface runoff. Significant differences were, however, observed between tillage treatments: flow-weighted concentrations of estradiol were greater for no-till than conventional-till plots of the June irrigation; and runoff loads of both estradiol and testosterone were less from no-till than conventional-till plots for the November irrigation. Although the differences between no-till and conventional-tillage appeared to affect the hydrologic transport of both hormones, the differences appeared to have inconsequential environmental impact.

  17. Cover crop rotations in no-till system: short-term CO2 emissions and soybean yield

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    João Paulo Gonsiorkiewicz Rigon

    Full Text Available ABSTRACT: In addition to improving sustainability in cropping systems, the use of a spring and winter crop rotation system may be a viable option for mitigating soil CO2 emissions (ECO2. This study aimed to determine short-term ECO2 as affected by crop rotations and soil management over one soybean cycle in two no-till experiments, and to assess the soybean yields with the lowest ECO2. Two experiments were carried out in fall-winter as follows: i triticale and sunflower were grown in Typic Rhodudalf (TR, and ii ruzigrass, grain sorghum, and ruzigrass + grain sorghum were grown in Rhodic Hapludox (RH. In the spring, pearl millet, sunn hemp, and forage sorghum were grown in both experiments. In addition, in TR a fallow treatment was also applied in the spring. Soybean was grown every year in the summer, and ECO2 were recorded during the growing period. The average ECO2 was 0.58 and 0.84 g m2 h–1 with accumulated ECO2 of 5,268 and 7,813 kg ha–1 C-CO2 in TR and RH, respectively. Sunn hemp, when compared to pearl millet, resulted in lower ECO2 by up to 12 % and an increase in soybean yield of 9% in TR. In RH, under the winter crop Ruzigrazz+Sorghum, ECO2 were lower by 17%, although with the same soybean yield. Soil moisture and N content of crop residues are the main drivers of ECO2 and soil clay content seems to play an important role in ECO2 that is worthy of further studies. In conclusion, sunn hemp in crop rotation may be utilized to mitigate ECO2 and improve soybean yield.

  18. Ammonia volatilization from enhanced-efficiency urea on no-till maize in brazilian cerrado with improved soil fertility

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    Eduardo Lopes Cancellier


    Full Text Available ABSTRACT High nitrogen losses by ammonia volatilization are expected when urea is used as the source of N. The use of controlled-release urea and urease inhibitors are possible strategies to reduce such losses and increase nitrogen use efficiency. This study aimed to evaluate nitrogen losses by ammonia volatilization from stabilized, slow and controlled release urea and its absorption by maize grown under no-till in an improved Cerrado soil. Four N sources were used: conventional urea, urea + N-(n-butyl thiophosphoric triamide (NBPT, urea + Cu and B and urea coated by sulfur + polymers. These N sources were surface applied along the rows using three N doses of 100, 150 and 200 kg ha-1. No N was added to the control. Data were collected regarding N losses by volatilization, the N contents accumulated in the stubble and grains, and the yields of the stubble and grains. Stabilized urea and slow release urea were efficient for postponing the ammonia volatilization peaks. The urease inhibitors postponed the peaks for up to two days, reducing the accumulated volatilization by 18% when compared with common urea. Polymer sulfur coated urea resulted in a 37% reduction in ammonia volatilization. Increasing the N application rate to 200 kg ha-1 resulted in 16% greater yields and 37% greater N accumulation in the plants relative to the control. However, the stabilized and slow-release urea did not improve the N accumulation or yield. Consequently, the nitrogen use efficiency of maize was not improved relative to the use of conventional urea.


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    Full Text Available Knowledge of the interactions between soil physical properties and yield performance in agricultural crops is very important for the adoption of appropriate management practices. This study aimed to evaluate the linear and spatial correlations between some soil physical attributes, straw production in the palisade grass (Urochloa brizantha, and grain yield of winter common bean in succession to the grass under an irrigated no-till system in an Oxisol Haplorthox in the Cerrado lowlands region of Brazil. The plant attributes determined were dry matter yield of U. brizantha (DMY, and grain yield (GY and final plant population (PP of winter common bean. The soil physical attributes, evaluated at 0.0-0.10 m and 0.10-0.20 m, were soil bulk density (BD, macroporosity (MA, microporosity (MI, total porosity (TP, penetration resistance (PR, gravimetric water content (GW, and volumetric water content (VW. A geostatistical grid with 124 sampling points was installed to collect the soil and plant data in an area of 4000 m2. The remaining straw amount of palisade grass exhibited an inverse linear correlation with bean yield and bean plant population when the bean was cultivated in succession. However, no spatial correlations were observed among the attributes. The common bean yield had a direct linear correlation with gravimetric water content in the 0.10-0.20 m soil layer. From a spatial point of view, winter bean yield showed a strong dependence on the distribution of the volumetric water content in the 0-0.10 m soil layer.

  20. Emergence dynamics of barnyardgrass and jimsonweed from two depths when switching from conventional to reduced and no-till conditions

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    Vasileios P. Vasileiadis


    Full Text Available A cylinder experiment was conducted in northern Greece during 2005 and 2006 to assess emergence dynamics of barnyardgrass (Echinochloa crus-galli (L. Beauv. and jimsonweed (Datura stramonium L. in the case of a switch from conventional to conservation tillage systems (CT. Emergence was surveyed from two burial depths (5 and 10 cm and with simulation of reduced tillage (i.e. by soil disturbance and no-till conditions. Barnyardgrass emergence was significantly affected by burial depth, having greater emergence from 5 cm depth (96% although even 78% of seedlings emerged from 10 cm depth after the two years of study. Emergence of barnyardgrass was stable across years from the different depths and tillage regimes. Jimsonweed seeds showed lower germination than barnyardgrass during the study period, whereas its emergence was significantly affected by soil disturbance having 41% compared to 28% without disturbance. A burial depth x soil disturbance interaction was also determined, which showed higher emergence from 10 cm depth with soil disturbance. Jimsonweed was found to have significantly higher emergence from 10 cm depth with soil disturbance in Year 2. Seasonal emergence timing of barnyardgrass did not vary between the different burial depth and soil disturbance regimes, as it started in April and lasted until end of May in both years. Jimsonweed showed a bimodal pattern, with first emergence starting end of April until mid-May and the second ranging from mid-June to mid-August from 10 cm burial depth and from mid-July to mid-August from 5 cm depth, irrespective of soil disturbance in both cases.

  1. Emergence dynamics of barnyardgrass and jimsonweed from two depths when switching from conventional to reduced and no-till conditions

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    Vasileiadis, V.; Froud-Williams, R.J.; Loddo, D.; Eleftherohorinos, I.G.


    A cylinder experiment was conducted in northern Greece during 2005 and 2006 to assess emergence dynamics of barnyardgrass (Echinochloa crus-galli (L.) Beauv.) and jimsonweed (Datura stramonium L.) in the case of a switch from conventional to conservation tillage systems (CT). Emergence was surveyed from two burial depths (5 and 10 cm) and with simulation of reduced tillage (i.e. by soil disturbance) and no-till conditions. Barnyardgrass emergence was significantly affected by burial depth, having greater emergence from 5 cm depth (96%) although even 78% of seedlings emerged from 10 cm depth after the two years of study. Emergence of barnyardgrass was stable across years from the different depths and tillage regimes. Jimsonweed seeds showed lower germination than barnyardgrass during the study period, whereas its emergence was significantly affected by soil disturbance having 41% compared to 28% without disturbance. A burial depth x soil disturbance interaction was also determined, which showed higher emergence from 10 cm depth with soil disturbance. Jimsonweed was found to have significantly higher emergence from 10 cm depth with soil disturbance in Year 2. Seasonal emergence timing of barnyardgrass did not vary between the different burial depth and soil disturbance regimes, as it started in April and lasted until end of May in both years. Jimsonweed showed a bimodal pattern, with first emergence starting end of April until mid-May and the second ranging from mid-June to mid-August from 10 cm burial depth and from mid-July to mid-August from 5 cm depth, irrespective of soil disturbance in both cases. (Author)

  2. Soil fertility, nutrition and yield of maize and barley with gypsum application on soil surface in no-till

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    Leandro Michalovicz


    Full Text Available Annual crop yield and nutrition have shown differentiated responses to modifications in soil chemical properties brought about by gypsum application. The aim of this study was to evaluate the effect of gypsum application rates on the chemical properties of a Latossolo Bruno (Clayey Oxisol, as well as on the nutrition and yield of a maize-barley succession under no-till. The experiment was set up in November 2009 in Guarapuava, Parana, Brazil, applying gypsum rates of 0.0, 1.5, 3.0, 4.5, and 6.0 Mg ha-1 to the soil surface upon sowing maize, with crop succession of barley. Gypsum application decreased the levels of Al3+ and Mg2+ in the 0.0-0.1 m layer and increased soil pH in the layers from 0.2-0.6 m depth. Gypsum application has increased the levels of Ca2+ in all soil layers up to 0.6 m, and the levels of S-SO4(2- up to 0.8 m. In both crops, the leaf concentrations of Ca and S were increased while Mg concentrations have decreased as a function of gypsum rates. There was also an effect of gypsum rates on grain yield, with a quadratic response of maize and a linear increase for barley. Yield increases were up to 11 and 12 % in relation to control for the maximum technical efficiency (MTE rates of 3.8 and 6.0 Mg ha-1 of gypsum, respectively. Gypsum application improved soil fertility in the profile, especially in the subsurface, as well as plant nutrition, increasing the yields of maize and barley.

  3. Modeling hydrology, metribuzin degradation and metribuzin transport in macroporous tilled and no-till silt loam soil using RZWQM. (United States)

    Malone, Robert W; Ma, Liwang; Wauchope, R Don; Ahuja, Lajpat R; Rojas, Kenneth W; Ma, Qingli; Warner, Richard; Byers, Matt


    Due to the complex nature of pesticide transport, process-based models can be difficult to use. For example, pesticide transport can be effected by macropore flow, and can be further complicated by sorption, desorption and degradation occurring at different rates in different soil compartments. We have used the Root Zone Water Quality Model (RZWQM) to investigate these phenomena with field data that included two management conditions (till and no-till) and metribuzin concentrations in percolate, runoff and soil. Metribuzin degradation and transport were simulated using three pesticide sorption models available in RZWQM: (a) instantaneous equilibrium-only (EO); (b) equilibrium-kinetic (EK, includes sites with slow desorption and no degradation); (c) equilibrium-bound (EB, includes irreversibly bound sites with relatively slow degradation). Site-specific RZWQM input included water retention curves from four soil depths, saturated hydraulic conductivity from four soil depths and the metribuzin partition coefficient. The calibrated parameters were macropore radius, surface crust saturated hydraulic conductivity, kinetic parameters, irreversible binding parameters and metribuzin half-life. The results indicate that (1) simulated metribuzin persistence was more accurate using the EK (root mean square error, RMSE = 0.03 kg ha(-1)) and EB (RMSE = 0.03 kg ha(-1)) sorption models compared to the EO (RMSE = 0.08 kg ha(-1)) model because of slowing metribuzin degradation rate with time and (2) simulating macropore flow resulted in prediction of metribuzin transport in percolate over the simulation period within a factor of two of that observed using all three pesticide sorption models. Moreover, little difference in simulated daily transport was observed between the three pesticide sorption models, except that the EB model substantially under-predicted metribuzin transport in runoff and percolate >30 days after application when transported concentrations were relatively low

  4. Farm-level economics of innovative tillage technologies: the case of no-till in the Altai Krai in Russian Siberia. (United States)

    Bavorova, Miroslava; Imamverdiyev, Nizami; Ponkina, Elena


    In the agricultural Altai Krai in Russian Siberia, soil degradation problems are prevalent. Agronomists recommend "reduced tillage systems," especially no-till, as a sustainable way to cultivate land that is threatened by soil degradation. In the Altai Krai, less is known about the technologies in practice. In this paper, we provide information on plant cultivation technologies used in the Altai Krai and on selected factors preventing farm managers in this region from adopting no-till technology based on our own quantitative survey conducted across 107 farms in 2015 and 2016. The results of the quantitative survey show that farm managers have high uncertainty regarding the use of no-till technology including its economics. To close this gap, we provide systematic analysis of factors influencing the economy of the plant production systems by using a farm optimization model (linear programming) for a real farm, together with expert estimations. The farm-specific results of the optimization model show that under optimal management and climatic conditions, the expert Modern Canadian no-till technology outperforms the farm min-till technology, but this is not the case for suboptimal conditions with lower yields.

  5. Long-term no-till and stover retention each decrease the global warming potential of irrigated continuous corn. (United States)

    Jin, Virginia L; Schmer, Marty R; Stewart, Catherine E; Sindelar, Aaron J; Varvel, Gary E; Wienhold, Brian J


    Over the last 50 years, the most increase in cultivated land area globally has been due to a doubling of irrigated land. Long-term agronomic management impacts on soil organic carbon (SOC) stocks, soil greenhouse gas (GHG) emissions, and global warming potential (GWP) in irrigated systems, however, remain relatively unknown. Here, residue and tillage management effects were quantified by measuring soil nitrous oxide (N 2 O) and methane (CH 4 ) fluxes and SOC changes (ΔSOC) at a long-term, irrigated continuous corn (Zea mays L.) system in eastern Nebraska, United States. Management treatments began in 2002, and measured treatments included no or high stover removal (0 or 6.8 Mg DM ha -1  yr -1 , respectively) under no-till (NT) or conventional disk tillage (CT) with full irrigation (n = 4). Soil N 2 O and CH 4 fluxes were measured for five crop-years (2011-2015), and ΔSOC was determined on an equivalent mass basis to ~30 cm soil depth. Both area- and yield-scaled soil N 2 O emissions were greater with stover retention compared to removal and for CT compared to NT, with no interaction between stover and tillage practices. Methane comprised <1% of total emissions, with NT being CH 4 neutral and CT a CH 4 source. Surface SOC decreased with stover removal and with CT after 14 years of management. When ΔSOC, soil GHG emissions, and agronomic energy usage were used to calculate system GWP, all management systems were net GHG sources. Conservation practices (NT, stover retention) each decreased system GWP compared to conventional practices (CT, stover removal), but pairing conservation practices conferred no additional mitigation benefit. Although cropping system, management equipment/timing/history, soil type, location, weather, and the depth to which ΔSOC is measured affect the GWP outcomes of irrigated systems at large, this long-term irrigated study provides valuable empirical evidence of how management decisions can impact soil GHG emissions and surface

  6. The Current State and Future Directions of Organic No-Till Farming with Cover Crops in Canada, with Case Study Support


    Heather M. Beach; Ken W. Laing; Morris Van De Walle; Ralph C. Martin


    Eliminating regular tillage practices in agriculture has numerous ecological benefits that correspond to the intentions of organic agriculture; yet, more tillage is conducted in organic agriculture than in conventional agriculture. Organic systems face more management challenges to avoid tillage. This paper identifies factors to consider when implementing no-till practices particularly in organic agronomic and vegetable crop agriculture and describes techniques to address these factors. In so...

  7. Qualitative attributes and postharvest conservation of green ears of maize grown on different cover crops in organic no-till system

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    Luiz Fernando Favarato

    Full Text Available ABSTRACT Postharvest quality of sweet maize varies depending on the type of seed, soil, quality of fertilizer, climatic conditions, and stage of maturation. This study aimed to evaluate the post-harvest quality and shelf life of green ears of maize grown on three soil covers in organic no-till sytem. The study was conducted in the municipality of Domingos Martins, ES (20° 22'16.91" S and 41° 03' 41.83" W. The experiment was arranged in a randomized block design with six replications and five treatments, consisting of three cover crops in organic no-till system: black-oat straw, white lupin, oat/lupin intercrop and two systems, organic and conventional, without straw. Maize double hybrid AG-1051 was sown in a spacing of 1.00 x 0.20 m. The variables evaluated included relative percentage of grain, straw and cob, pH, titratable acidity, soluble solids, grain moisture and shelf life. The use of different straws in the organic no-till system does not influence the postharvest quality of green ears. Ears packed in polystyrene trays with plastic film are suitable for marketing until the fifth day of storage at room temperature.

  8. Impact of Amendments on the Physical Properties of Soil under Tropical Long-Term No Till Conditions. (United States)

    Carmeis Filho, Antonio C A; Crusciol, Carlos A C; Guimarães, Tiara M; Calonego, Juliano C; Mooney, Sacha J


    Tropical regions have been considered the world's primary agricultural frontier; however, some physico-chemical deficiencies, such as low soil organic matter content, poor soil structure, high erodibility, soil acidity, and aluminum toxicity, have affected their productive capacity. Lime and gypsum are commonly used to improve soil chemical fertility, but no information exists about the long-term effects of these products on the physical attributes and C protection mechanisms of highly weathered Oxisols. A field trial was conducted in a sandy clay loam (kaolinitic, thermic Typic Haplorthox) under a no-tillage system for 12 years. The trial consisted of four treatments: a control with no soil amendment application, the application of 2.1 Mg ha-1 phosphogypsum, the application of 2.0 Mg ha-1 lime, and the application of lime + phosphogypsum (2.0 + 2.1 Mg ha-1, respectively). Since the experiment was established in 2002, the rates have been applied three times (2002, 2004, and 2010). Surface liming effectively increased water-stable aggregates > 2.0 mm at a depth of up to 0.2 m; however, the association with phosphogypsum was considered a good strategy to improve the macroaggregate stability in subsoil layers (0.20 to 0.40 m). Consequently, both soil amendments applied together increased the mean weight diameter (MWD) and geometric mean diameter (GMD) in all soil layers, with increases of up to 118 and 89%, respectively, according to the soil layer. The formation and stabilization of larger aggregates contributed to a higher accumulation of total organic carbon (TOC) on these structures. In addition to TOC, the MWD and aggregate stability index were positively correlated with Ca2+ and Mg2+ levels and base saturation. Consequently, the increase observed in the aggregate size class resulted in a better organization of soil particles, increasing the macroporosity and reducing the soil bulk density and penetration resistance. Therefore, adequate soil chemical management

  9. Production of N2O and CO2 in Tillage and no Till Dryland and Irrigated Wheat Systems in Response to Additions of Water and N Fertilizer (United States)

    Kostyanovsky, K.; Huggins, D.; Stockle, C.; Smith, J. L.; Morrow, J.; Lamb, B. K.; Pressley, S. N.; Waldo, S.; Brown, D. J.; Pan, W.


    Rainfall, irrigation and soil N fertilization are significant processes which drive emissions of highly potent greenhouse gas nitrous oxide, the major contributor to climate change from agriculture. Changing climate is likely to result in shifting of agroecozones due to increased temperatures, and expansion of irrigated agriculture as well as increase in irrigation requirements. An accurate assessment of N2O in irrigation and dryland scenarios is required for predicting the effects of these agricultural management practices on global climate change. The effects of N application and water additions on CO2 and N2O emissions were evaluated on long-term no-tillage and conventional tillage sites of dryland and irrigated wheat cropping systems in the Pacific Northwest. We implemented the system of Li-Cor 8100A automatic chambers coupled with LGR 23r N2O analyzer for continuous IRGA monitoring of CO2 and N2O emissions in the short term microplot study with the following treatments: 1) no water; 2) water added to 80% water filled pore space and amended with 150 kg NH4NO3-N ha-1; 3) water added to 80% water filled pore space. Application of N and water took place at 9:00 and the measurements continued from that time until 7:00 the following day for 22 hrs. The study was conducted in the summer and repeated in fall, which are most likely to be affected by increased temperatures. Nitrogen and water treatments resulted in higher N2O peaks than water only treatments. Both N plus water and only water treatments had higher N2O emissions than the no water treatments. Conventional tillage treatments resulted in N2O emissions 30-40% than no-till treatments. Emissions of CO2 tended to be increased in the fertilized and water added treatments compared to just water added treatments, and both of these treatments had higher CO2 emissions than treatments without water added. Tillage treatments also tended to have higher CO2 emissions than no-till treatments. Emissions of CO2 and N2O were

  10. Soil physical and X-ray computed tomographic measurements to investigate small-scale structural differences under strip tillage compared to mulch till and no-till (United States)

    Pöhlitz, Julia; Rücknagel, Jan; Schlüter, Steffen; Vogel, Hans-Jörg


    In recent years there has been an increasing application of conservation tillage techniques where the soil is no longer turned, but only loosened or left completely untilled. Dead plant material remains on the soil surface, which provides environmental and economic benefits such as the conservation of water, preventing soil erosion and saving time during seedbed preparation. There is a variety of conservation tillage systems, e.g. mulch till, no-till and strip tillage, which is a special feature. In strip tillage, the seed bed is divided into a seed zone (strip-till within the seed row: STWS) and a soil management zone (strip-till between the seed row: STBS). However, each tillage application affects physical soil properties and processes. Here, the combined application of classical soil mechanical and computed tomographic methods is used on a Chernozem (texture 0-30 cm: silt loam) to show small-scale structural differences under strip tillage (STWS, STBS) compared to no-till (NT) and mulch till (MT). In addition to the classical soil physical parameters dry bulk density and saturated conductivity (years: 2012, 2014, 2015) at soil depths 2-8 and 12-18 cm, stress-strain tests were carried out to map mechanical behavior. The stress-strain tests were performed for a load range from 5-550 kPa at 12-18 cm depth (year 2015). Mechanical precompression stress was determined on the stress-dry bulk density curves. Further, CT image cross sections and computed tomographic examinations (average pore size, porosity, connectivity, and anisotropy) were used from the same soil samples. For STBS and NT, a significant increase in dry bulk density was observed over the course of time compared to STWS and MT, which was more pronounced at 2-8 cm than at 12-18 cm depth. Despite higher dry bulk density, STBS displayed higher saturated conductivity in contrast to STWS, which can be attributed to higher earthworm abundance. In strip tillage, structural differences were identified

  11. Manejo de rebrotes de Digitaria insularis no plantio direto de milho Management of Digitaria insularis sprouts under no-till corn cultivation

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    P.C. Timossi


    Full Text Available Com a dessecação da vegetação espontânea, nem sempre se consegue obter controle total das espécies daninhas, o que leva à perenização e ao aumento da importância daquelas selecionadas. Em área de plantio direto com predominância de rebrotes de Digitaria insularis, foi testado nicosulfuron isolado (60 g ha-1 e em mistura em tanque com atrazine (40 + 1.500 g ha-1, foramsulfuron + iodosulfuron-methyl (45 + 3 g ha-1 e mesotrione em mistura em tanque com atrazine (144 + 1.500 g ha-1 sob delineamento de blocos ao acaso, com quatro repetições. Cada parcela apresentava 6 x 4 m, contendo seis linhas de milho. A aplicação dos herbicidas foi feita com pulverizador costal na pressão constante de 30 lbf pol-2, com gasto de 200L ha-1 de calda. Foram avaliadas a eficácia e a intoxicação dos herbicidas aos 7, 15 e 30 dias após a aplicação na cultura. Na época da colheita, realizouse levantamento da cobertura vegetal reinfestante e do seu grau de dificuldade de colheita mecanizada, além da produtividade da cultura. Pode-se inferir que o melhor resultado para o manejo de rebrotes de D. insularis foi com a utilização de nicosulfuron isolado a 60 g ha-1.Total weed control is not always possible under no-till desiccation leading to perennial and increased number of weeds. In no-till cultivation areas with predominant occurrence of Digitaria insularis sprouts, nicosulfuron alone (60 g ha-1 and in tank mix with atrazine (40 + 1.500 g ha-1, foramsulfuron + iodosulfuron-methyl (45 + 3 g ha-1 and mesotrione in tank mix with atrazine (144 + 1.500 g ha-1 were tested in a randomized block design, with four replications. Each plot was 6 x 4 m, containing six corn culture rows. The herbicides were applied with a back spray at a constant pressure of 30 lbf pol-2, using 200 L ha-1 solution. Herbicide efficacy and toxicity were evaluated at 7, 15 and 30 days after application. During harvest, reinfesting plant cover and its degree of mechanized harvest

  12. Integração lavoura e pecuária e os atributos físicos de solo manejado sob sistema plantio direto Livestock-crop integration effects on physical attributes of a soil under no-till

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    Silvio Tulio Spera


    evaluated: I wheat/soybean, white oat/soybean, and common vetch/corn; II wheat/soybean, white oat/soybean, and annual forages (black oat + common vetch/corn; III perennial cool season forages (fescue + white clover + red clover + birdsfoot trefoil; and IV perennial warm season forages (bahiagrass + black oat + rye grass + white clover + red clover + birdsfoot trefoil. System V alfalfa as hay crop was established in an adjacent area in 1994. Half of the areas under the systems III, IV, and V returned to system I after the summer of 1996 (southern hemisphere. The crops, both summer and winter, were grown under no-till. The treatments were arranged in a randomized complete block design, with four replications. Soil core samples were also collected in a subtropical forest fragment adjacent to the experimental area. The variations in soil bulk density, total porosity, microporosity and macroporosity due to grain production systems with forages were not severe enough to cause soil degradation. The soil bulk density in the production systems with perennial forages was lower and total porosity and macroporosity, in the 0-2 cm layer, higher than in the production systems of grain or of grain with annual forages.

  13. Effects of Intra-Storm Soil Moisture and Runoff Characteristics on Ephemeral Gully Development: Evidence from a No-Till Field Study

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    Vladimir R. Karimov


    Full Text Available Ephemeral gully erosion, prevalent on agricultural landscapes of the Great Plains, is recognized as a large source of soil loss and a substantial contributor to the sedimentation of small ponds and large reservoirs. Multi-seasonal field studies can provide needed information on ephemeral gully development and its relationship to physical factors associated with field characteristics, rainfall patterns, runoff hydrograph, and management practices. In this study, an ephemeral gully on a no-till cultivated crop field in central Kansas, U.S., was monitored in 2013 and 2014. Data collection included continuous sub-hourly precipitation, soil moisture, soil temperature, and 15 field surveys of cross-sectional profiles in the headcut and channelized parts of the gully. Rainfall excess from a contributing catchment was calculated with the Water Erosion Prediction Project (WEPP model for all storm events and validated on channel flow measurements. Twelve significant runoff events with hydraulic shear stresses higher than the critical value were identified to potentially cause soil erosion in three out of fourteen survey periods. Analysis of shear stress imposed by peak channel flow on soil surface, antecedent soil moisture condition, and channel shape at individual events provided the basis on which to extend the definition of the critical shear stress function by incorporating the intra-storm changes in soil moisture content. One potential form of this function was suggested and tested with collected data. Similar field studies in other agriculturally-dominated areas and laboratory experiments can develop datasets for a better understanding of the physical mechanisms associated with ephemeral gully progression.

  14. A Multi-Year Comparison of No-Till Versus Conventional-Till Effects on the Carbon Balance in a Corn/Soybean Agro-Ecosystem Using Eddy Covariance (United States)

    Joo, E.; Slattery, R.; Meyers, T. P.; Bernacchi, C.


    Dramatic increases in atmospheric CO2 concentrations since the industrial revolution are in large part due to the release of carbon previously stored in the soil. No-till strategies have been proposed as a means to mitigate agricultural contributions to atmospheric carbon by decreasing emissions and sequestering carbon in agricultural soils while increasing water use efficiency and soil quality. However, the effects of no-till versus conventional-till practices on carbon sequestration often vary due to difficulty in quantifying soil carbon as soil properties change with management. Eddy covariance (EC) offers a more accurate method of continuously measuring the total carbon budget and does so without relying on physical soil carbon measurements. The majority of agricultural land in the Midwestern United States is farmed using the corn/soybean rotation, making it an ideal agro-ecosystem to examine the potential of adopting no-till practices on carbon and water balances. In this study, we use EC to compare carbon and water fluxes between continuous no-till and conventional-till corn/soybean sites over several years in east central Illinois. This allows the determination and comparison of 1) net ecosystem exchange (NEE) and net biome production (NEE after accounting for grain usage); 2) water use efficiency; and 3) response to climatic variation, both at short and long time scales, between the two tillage systems. We hypothesize that both carbon uptake and water use efficiency will improve with no-till practices, which in turn will improve crop responses to environmental factors such as drought and heat stress.

  15. Effects of water-saving irrigation practices and drought resistant rice variety on greenhouse gas emissions from a no-till paddy in the central lowlands of China

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Ying; Ge, Junzhu; Tian, Shaoyang; Li, Shuya [MOA Key Laboratory of Crop Physiology, Ecology and Cultivation (The Middle Reaches of Yangtze River), Huazhong Agricultural University, Wuhan, Hubei 430070 (China); College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070 (China); Nguy-Robertson, Anthony L. [Center for Advanced Land Management Information Technologies, School of Natural Resources, University of Nebraska-Lincoln, Lincoln, NE 68583-0973 (United States); Zhan, Ming, E-mail: [MOA Key Laboratory of Crop Physiology, Ecology and Cultivation (The Middle Reaches of Yangtze River), Huazhong Agricultural University, Wuhan, Hubei 430070 (China); College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070 (China); Cao, Cougui, E-mail: [MOA Key Laboratory of Crop Physiology, Ecology and Cultivation (The Middle Reaches of Yangtze River), Huazhong Agricultural University, Wuhan, Hubei 430070 (China); College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070 (China)


    As pressure on water resources increases, alternative practices to conserve water in paddies have been developed. Few studies have simultaneously examined the effectiveness of different water regimes on conserving water, mitigating greenhouse gases (GHG), and maintaining yields in rice production. This study, which was conducted during the drought of 2013, examined all three factors using a split-plot experiment with two rice varieties in a no-till paddy managed under three different water regimes: 1) continuous flooding (CF), 2) flooded and wet intermittent irrigation (FWI), and 3) flooded and dry intermittent irrigation (FDI). The Methane (CH{sub 4}) and nitrous oxide (N{sub 2}O) emissions were measured using static chamber-gas measurements, and the carbon dioxide (CO{sub 2}) emissions were monitored using a soil CO{sub 2} flux system (LI-8100). Compared with CF, FWI and FDI irrigation strategies reduced CH{sub 4} emissions by 60% and 83%, respectively. In contrast, CO{sub 2} and N{sub 2}O fluxes increased by 65% and 9%, respectively, under FWI watering regime and by 104% and 11%, respectively, under FDI managed plots. Although CO{sub 2} and N{sub 2}O emissions increased, the global warming potential (GWP) and greenhouse gas intensity (GHGI) of all three GHG decreased by up to 25% and 29% (p < 0.01), respectively, using water-saving irrigation strategies. The rice variety also affected yields and GHG emissions in response to different water regimes. The drought-resistance rice variety (HY3) was observed to maintain yields, conserve water, and reduce GHG under the FWI irrigation management compared with the typical variety (FYY299) planted in the region. The FYY299 only had significantly lower GWP and GHGI when the yield was reduced under FDI water regime. In conclusion, FWI irrigation strategy could be an effective option for simultaneously saving water and mitigating GWP without reducing rice yields using drought-resistant rice varieties, such as HY3

  16. Dessecação do campo nativo para semeadura direta da cultura da soja Native pasture desiccation for no-till soybeans seeding

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    Miguel Vicente Weiss Ferri


    Full Text Available Para avaliar doses do herbicida glyphosate, isolado ou misturado com 2,4-D, na dessecação do campo nativo para semeadura direta de soja, foi conduzido um experimento no compus da UFSM. Os tratamentos foram: glyphosate a 360, 720 e 1080g ha-1 de equivalente ácido, isolado ou em mistura com 200g ha-1 de 2,4-D éster, aspergidos em dois volumes de calda (50 e 200l ha-1, além de testemunha sem controle. A aspersão dos herbicidas ocorreu em 30/10/95 e a semeadura da soja em 27/12/95. Das 57 espécies presentes no campo nativo, as principais foram: Paspalum notatum var. notatum biótipos "C" e "D", Vernonia polyanthes, Vernonia nudiflora, Eryngium horridum e Baccharis trimera. Os resultados mostram que o uso de 2,4-D e a redução do volume de calda de 200 para 50l ha-1 não melhoraram a eficácia de controle do glyphosate, que mostrou controle geral de 48, 73 e 90% para as doses de 360, 720 e 1080g ha-1. O glyphosate mostrou controle ineficiente de V. polyanthes, V. nudiflora e E. horridum, independente da dose ou mistura com 2,4-D, sendo eficiente para B. trimera à 720 e 1080g ha-1. Houve controle do Paspalum de 54, 79 e 93% para o glyphosate à 360, 720 e 1080g ha-1 . O rendimento médio de grãos de soja foi de 1762, 2502, 2690 e 2793 kg ha-1, para testemunha e glyphosate a 360, 720 e 1080g ha-1. Conclui-se que, para semeadura direta de soja sobre campo nativo, a dose de 1080g ha-1 de glyphosate é adequada.The objective of this study was to evaluate rates of glyphosate herbicide applyed alone or in mixture with 2,4-D ester herbicide, to control nativo pasture before planting soybeans in a no-till system. The following treatments were tested: glyphosate at 360, 720, and 1080g ha-1 of acid equivalent, alone or in mixture with 200g ha-1 of 2,4-D, sprayed at two volumes (50 and 200l ha-1, and unsprayed control. Herbicides were sprayed in 10/30/95 and soybean was seeded in 12/27/95 in study carried out at the Federal University of Santa Maria

  17. Organomineral Interactions and Herbicide Sorption in Brazilian Tropical and Subtropical Oxisols under No-Tillage. (United States)

    Bonfleur, Eloana J; Kookana, Rai S; Tornisielo, Valdemar L; Regitano, Jussara B


    We evaluated the effects of the soil organic matter (SOM) composition, distribution between soil aggregates size, and their interactions with the mineral phase on herbicide sorption (alachlor, bentazon, and imazethapyr) in tropical and subtropical Oxisols under no-till systems (NT). Using soil physical fractionation approach, sorption experiments were performed on whole soils and their aggregates. SOM chemistry was assessed by CP/MAS (13)C NMR. The lower sorption observed in tropical soils was attributed to the greater blockage of SOM sorption sites than in subtropical soils. When these sites were exposed upon physical fractionation, sorption of the three herbicides in tropical soils increased, especially for imazethapyr. High amounts of poorly crystallized sesquioxides in these soils may have contributed to masking of sorption sites, indicating that organomineral interactions may lead to blockage of sorption sites on SOM in tropical soils.

  18. Acidification evidences of no-tilled soils of the central region of argentina Evidencias de acidificación de suelos de la región central de la argentina bajo siembra directa


    Laura Antonela Iturri; Daniel Eduardo Buschiazzo; Martín Díaz-Zorita


    Empiric evidences indicate that agricultural soils of Argentina tend to acidify. The objective of this study was to determine the pH values of no-tilled and urea-fertilized-agricultural soils of Argentina during several years. Results indicated that both the actual pH (pH A) and the potential pH (pH P) values were lower in humid than in dry environments. The ratio between «mean annual precipitation:mean annual temperature» of the sites explained between 60 and 80% of the variability in pH val...

  19. Sandy Hook Traveler Information System (United States)


    This report focuses on equipment and procedural solutions for gathering and disseminating a wide range of visitor information, including real-time traveler information data relating to traffic and parking at the Sandy Hook Unit of the Gateway Recreat...

  20. Compressibility of Oxisol aggregates under no-till in response to soil water potential Compressibilidade de agregados de Latossolo Vermelho sob plantio direto em resposta ao potencial da água do solo

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    João Tavares Filho


    Full Text Available The system of no-till sowing stands out as being a technology that suits the objectives of more rational use of the soil and greater protection against the erosion. However, through till, any of it, occurs modifications of the soil's structure. This current work aims to study the influence of the energy state of the water and of the organic matter on the mechanism of compaction of Red Oxisol under no-till management system. Humid and non-deformed sample were collected in horizon AP of two agricultural areas under no-till, with and without rotation of cultures. In the laboratory, these samples were broken into fragments and sifted to obtain aggregates of 4 to 5 mm sized, which were placed in equilibrium under four matrix potentials. Thereafter, they were exposed to uni-dimensional compression with pressures varying from 32 to 1,000 kPa. The results in such a way show that the highest compressibility of aggregates both for the tilling with rotation of cultures as for the tilling without rotation of cultures, occurred for matrix potential -32 kPa (humidity of 0.29-0.32 kg kg-1, respectively, while the minor occurred for the potentials of -1 and -1,000 kPa (humidity of 0.35 and 0.27 kg kg-1, respectively, indicating that this soil should not be worked with humidity ranging around 0.29 to 0.32 kg kg-1 and the highest reduction of volume of aggregates was obtained for the mechanical pressures lower than 600 inferior kPa, indicating that these soils showed to be very influenced by compression, when exposed to mechanical work. Also, the aggregates of soil under no-till and rotation of crops presented higher sensitivity to the compression than the aggregates of soil under no-till and without rotation of crops, possibly for having better structural conditions given to a higher content of organic matter.O sistema de semeadura direta destaca-se como uma tecnologia que atende aos objetivos de uso mais racional do solo e maior proteção contra a eros

  1. Produção de milho em plantio direto com adubação nitrogenada e cobertura do solo na pré-safra Corn in no-till system with nitrogen fertilization and soil cover crops preceding

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    Itamar Andrioli


    alternative to supply nitrogen (N and to make no-till system viable regions with dry winter such as in the Southeast, Center-West, North, and Northeast of Brazil. The purpose of this study was to evaluate N levels and the effect of cover plants on N supply and corn yield in no-till system. The study was carried out from 2000 to 2003. The experimental design was randomized blocks, with split-split plots and four replicates. The main plot treatments were four use and management systems: corn in no-till after Crotalaria juncea, corn in no-till after Brachiaria brizantha in the first year and Dolechus lablab in the two last ones (PDlab, corn in no-till after Pennisetum americanum (PDmil and corn in conventional system after winter fallow (PC and the subplot treatments were three side-dressed N levels (0, 60 and 120 kg ha-1. Corn aboveground dry mass, yield, accumulated N and N use efficiency were evaluated. N use efficiency by corn was higher in PDcrot and PC in comparison to PDlab and PDmil, which showed a similar response. The maximum corn yield was 7,259; 7,234; 6,723 and 6,461 kg ha-1, with N levels of 97.1, 120.0, 87.8 and 96.1 kg ha-1 in PDcrot, PC, PDlab and PDmil, respectively. Grain yield in no-tillage-corn after Crotalaria cover crop was higher than that following millet and lablab.

  2. Perda de nutrientes via escoamento superficial no sistema plantio direto sob adubação mineral e orgânica Nutrient losses by surface runoff in no-till system soil under mineral and organic fertilization

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    Oromar João Bertol


    under no-till system and submitted to simulated after application of organic or mineral fertilizers in no-till soil. The fertilizers did not affect the concentration of mineral elements studied nutrients in runoff, except in condition of more high intense rainfall and soil under after organic manure application, which promoted runoff with showed the higher highest concentration of soluble and total K. Independent Irrespective of the type of fertilizers utilized type, the rainfall of higher intensity resulted in higher concentrations of all the mineral elements and forms studied, either in total, soluble or particulate form, evidencing the economic and environmental benefices, risks and suggesting that with the adoption of practices for runoff contention of runoff practices must be adopted , even in tilled croplands areas managed under no-till system.

  3. Phosphorus loss by surface runoff in no-till system under mineral and organic fertilization Perda de fósforo via escoamento superficial no sistema plantio direto sob adubação mineral e orgânica

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    Oromar João Bertol


    Full Text Available The no-till system has been intensively used in the state of Paraná, Brazil, and it has increased the nutrients level at the soil surface. This has contributed for nutrient losses via runoff and consequently, off-site water pollution. The objective of this study was to evaluate phosphorus loss in surface runoff by simulated rainfall on an Oxisol, under no-till system following application of mineral fertilizer and liquid swine manure. Nitrogen, soil and water losses from the same study are reported in a separated paper. The application of liquid swine manure, compared with mineral fertilization, increased runoff concentration of total P, particulate P and dissolved reactive P by 193%, 111% and 506%, respectively, averaged for all rainfall intensities. Independently on the fertilizer source, the highest rainfall intensity provided the greatest concentration and loads of P in runoff.O sistema plantio direto tem sito intensivamente utilizado no Estado do Paraná Brasil o qual tem aumentado os níveis de nutrientes na superfície do solo. Isto tem contribuído para a perda de nutrientes via escoamento superficial e consequentemente com a poluição não pontual das águas. Avaliou-se a perda de fósforo via escoamento superficial ocasionado por chuva simulada sobre um Latossolo originário de basalto, em sistema plantio direto submetido à aplicação de fertilizante mineral e dejeto líquido de suíno. As perdas de nitrogênio, solo e água deste mesmo estudo foram publicadas em outro artigo. A aplicação de dejeto líquido suíno, comparado com o fertilizante mineral, aumentou a concentração de P total, P particulado e P dissolvido reativo em 193%, 111% e 506%, respectivamente, na média das chuvas. Independentemente da fonte de fertilizante, a chuva de maior intensidade proporcionou maior concentração e quantidade perdida de P no escoamento superficial.

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    Department of Homeland Security — Sandy PMO: Disaster Relief Appropriations Act of 2013 (Sandy Supplemental Bill) Financial Data. This is the Sandy Supplemental Quarterly Financial Datasets that are...

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    National Oceanic and Atmospheric Administration, Department of Commerce — Hurricane Sandy poster. Multi-spectral image from Suomi-NPP shows Hurricane Sandy approaching the New Jersey Coast on October 29, 2012. Poster size is approximately...

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    Strang, Craig; And Others

    The activities in this guide (for grades 2-4) transport students to the sandy shore, one of the most fascinating ecosystems on the planet. At this ecological juncture a multiplicity of life forms find ways to survive, thrive, and interact with each other. Using a wide variety of learning formats, students explore and deepen their understanding of…

  7. Sistemas de dessecação antecedendo a semeadura direta de milho e controle de plantas daninhas Desiccation systems prior to no-till corn sowing and weed control

    Directory of Open Access Journals (Sweden)

    Jamil Constantin


    Full Text Available No sistema de plantio direto, a escolha do momento adequado para a dessecação da cobertura vegetal antecedente à semeadura é fundamental para o êxito da cultura do milho. O objetivo do trabalho foi avaliar os efeitos sobre a cultura do milho de três sistemas de dessecação de manejo antecedendo o plantio direto combinados com três métodos de controle de plantas daninhas, em áreas com alta densidade de infestação de ervas. Os tratamentos foram arranjados em esquema fatorial (3x3 + 1, em delineamento de blocos casualizados, com cinco repetições. Os três sistemas de dessecação avaliados foram: (1 dessecação de manejo realizada imediatamente antes da semeadura - sistema Aplique-Plante ("AP"; (2 dessecação de manejo realizada sete dias antes da semeadura direta (DAS ("7 DAS"; e (3 manejo antecipado ("MA", quando as dessecações foram realizadas aos 25 e 1 DAS do milho. Após a emergência da cultura, as opções de controle foram: (1 nenhum controle de plantas daninhas; (2 capina manual e (3 aplicação de mesotrione + atrazine + óleo mineral em pós-emergência, além de uma testemunha sem manejo e sem controle em pós-emergência. Verificou-se que, após a emergência da cultura, a utilização do MA proporcionou maior controle das plantas daninhas, em comparação com os sistemas AP e 7 DAS. Evidenciou-se um atraso de crescimento nas plantas de milho crescidas nas áreas onde foi utilizado o sistema AP. Observou ainda que, independentemente do método de controle de plantas daninhas utilizado em pós-emergência, os maiores rendimentos de grãos de milho ocorreram no MA com ganhos que variaram entre 593 a 1060 kg ha-1.The adequate timing for cover crop management before sowing is fundamental for the success of no-till corn. This research aimed to evaluate the effects on corn growth and yield of three burndown systems before no-till sowing, combined with three weeds control methods after crop emergence, in areas with high

  8. Effects of early compost application on no-till organic soybean Resposta à antecipação da adubação com composto orgânico na soja orgânica em plantio direto

    Directory of Open Access Journals (Sweden)

    L.A.O. Penha


    Full Text Available Weed control has always been an important issue in agriculture. With the advent of no-till systems, soil erosion was reduced but herbicide use was increased. Organic no-till systems try to adjust reduced erosion to the no use of herbicides. Nevertheless, this adjustment is limited by the cost of mechanical weed control. This cost may be reduced by improved cultural weed control with cover crops mulches. In this paper we report a study on the application of compost manure on an oats winter cover crop, preceding soybean, instead of on the soybean summer crop. Treatments comprised a control without compost manure, and compost manure doses of 4 and 8 Mg ha-1 applied either on oats in winter or soybean in summer, organized in a randomized block design, with five replications. In summer, plots were split into weed-controlled or not controlled subplots. The timing of application and the manure doses did not affect the oats biomass or the soybean performance. However, in summer, without water stress, the application of manure at 8 Mg ha-1 directly on soybean has reduced weed biomass in this crop.O controle de plantas daninhas sempre foi um fator importante na agricultura. Com o advento do plantio direto reduziu-se a erosão do solo, mas houve aumento no uso de herbicidas. O plantio direto orgânico busca conciliar o controle da erosão com a eliminação do uso de herbicidas, porém o custo de produção é onerado pela necessidade de controle mecânico das plantas daninhas. Esse custo poderia ser reduzido por um melhor controle cultural com palhas produzidas por plantas de cobertura no inverno. Neste trabalho, antecipou-se a adubação da soja para a aveia, aplicando na aveia o adubo que seria aplicado na soja, de modo a aumentar a quantidade de palha de aveia sobre a qual a soja seria semeada no verão seguinte. O delineamento experimental foi em blocos ao acaso com parcelas subdivididas. Os tratamentos foram uma testemunha sem adubação e duas doses

  9. Effect of cover crops on common bean yield and soil physical properties under no-till system - doi: 10.4025/actascitechnol.v34i4.11989

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    Edleusa Pereira Seidel


    Full Text Available The aim of this study was to evaluate dry matter production of cover crops (oats, turnip, vetch and spontaneous plants and their effect on bean yield and physical properties of soil after succession. The experimental design was randomized blocks, and treatments consisted of four species of cover crops: oat, turnip, vetch and spontaneous plants, with five replications. The cover crops were sown in winter; when in full bloom, they were cut close to the ground and left underground. The bean crop was then sown underneath this residue in a no-till system. The results show that the cover crop that yielded the most dry matter was oats with 4,900 kg ha-1, which did not differ statistically from turnip with a yield of 4,000 kg ha-1. The spontaneous plants produced the least amount of dry matter and differed from the other treatments. The development of vetch was hampered by the environmental conditions of Marechal Cândido Rondon, State of Paraná, with dry matter yield of 2,375 kg ha-1. The highest bean yield (1,204 kg ha-1 was found for the planting carried out in succession to oat, and the lowest after succession of vetch (697 kg ha-1 and spontaneous plants (575 kg ha-1. Cover crops had no effect on macroporosity and total porosity of soil depth from 0.05 to 0.20 m. There was a statistical difference in soil bulk density in the layer from 0.05 to 0.10 m, and bulk density (1.18 kg dm-3 was obtained in the treatment where the bean crop was cultivated after spontaneous plants.

  10. Variabilidade horizontal da fertilidade do solo de uma unidade de amostragem em sistema plantio direto Horizontal variability of soil fertility in a sampling unit under no-till system

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    V. H. Alvarez V.


    com pá de corte. A variabilidade foi baixa para pH, P-rem e H + Al e alta para P, Al3+, Mg2+, K e Ca2+. Dez amostras simples coletadas com pá de corte ou 27 amostras simples coletadas de forma localizada com trado de caneca (cinco amostras coletadas no sulco de plantio, nove coletadas a 10 cm do sulco e 13 coletadas no ponto médio entre sulcos foram necessárias à formação de amostras compostas representativas. As análises das amostras compostas, tanto de pá de corte quanto de trado, apresentaram valores semelhantes às médias das análises das respectivas amostras simples, caracterizando corretamente a fertilidade média da unidade de amostragem.Sampling soil with the auger hole is simpler and faster than with the cutting shovel. The last is frequently used in no till systems to obtain soil samples for fertility analyses. This study had the following objectives: comparison of two different localized soil sampling systems concerning the horizontal variability of chemical soil characteristics; determination of the necessary unit number to compose a representative sample of the area, and the demonstration that mean fertility values obtained from the composite sample are the same as the obtained from the arithmetic mean of single samplings. The study was carried out in an area under no till system since 15 years. The localized sampling systems were: cutting shovel (24 single samples collected perpendicularly to the furrow and in the middle of the space between two furrows and auger hole (20 single samples collected in the planting furrow (Ts, 20 single samples collected 10 cm beside the furrow (T10, and 20 single samples collected 40 cm beside the furrow (T40.Representative sub-samples of both methods were randomly chosen from the single ones, and mixed to make up respective composite samples. P, K, Ca2+, Mg2+, and Al3+, and the values of pH, H + Al, and P-rem were determined in the single and composite samples, and their means, standard deviation, and variation

  11. Utilização de acetochlor e atrazine aplicados em mistura de tanque com dessecantes no sistema de plantio direto Reaction of the herbicides acetochlor and atrazine applied in tank mixtures with desiccants in no-till system

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    Benedito N. Rodrigues


    "rolada", em qualquer tratamento; neste caso, os maiores valores foram 91% para atrazine+óleo vegetal e 90% para atrazine+glyphosate+2,4D. Na modalidade "em pé'', os maiores valores foram obtidos com atrazine+óleo vegetal (77 % e com atrazine+glyphosate+2,4D (70 %.Tank mix involving desiccants plus residual herbicides have been used by farmers in no- till system. Nevertheless, it has been commented that the residual herbicides can stay retained in the straw when used in pre-emergence in this system. The objective of this trial, was to study the reaction of the residual herbicides atrazine and acetochlor in tank mix with desiccants herbicides for corn crop in no-till system. The experiment was settled in Londrina, State of Paraná, using a randomized complete block design in a split plot arrangement. Nine treatments were located at the main plots: 1 acetochlor + glyphosate; 2 acetochlor + glyphosate + 2,4D; 3 acetochlor + paraquat; 4 acetochlor + paraquat + 2,4D; 5 atrazine + glyphosate; 6 atrazine + glyphosate + 2,4D; 7 atrazine + paraquat; 8 atrazine + vegetal oil; 9 check without herbicides. Two modalities of herbicides application of herbicides were tested in split plots: 1 application on a "non rolled" cover crops; 2 application on a "rolled"cover crops. The winter cover crops were a mixture of plants formed by Avena strigosa Schreb plus Vicia sativa L. The best control of Brachiaria plantaginea, Euphorbia heterophylla and Bidens pilosa was obtained with atrazine treatments. In general terms, the treatments "non rolled" were better than the "rolled" ones for weed control. The chromatografic analysis of the soil sampled from the plots before and after 41 mm of a rainfall that occured 24 h after application of the herbicides, showed that less than 6% of the acetochlor applied was detected in soil in both modalities of application. In respect to atrazine however, more than 78% of the total applied was detected in soil after the rain in the "rolled" modality in any


    Haley, Boyd R.; Bitar, Richard F.


    The Sandy Creek Roadless Area includes about 3. 7 sq mi in the southeastern part of Adams County, Mississippi. On the basis of a mineral survey, the area offers little promise for the occurrence of metallic mineral resources but has a probable resource potential for oil and natural gas. It is possible that wells drilled deep enough to penetrate the older reservoirs will encounter significant quantities of oil and natural gas in the roadless area. The deposits of gravel, sand, and clay present in the area could be utilized in the construction industry, but similar deposits elsewhere are much closer to available markets.

  13. Variabilidade e correlação espacial de propriedades físicas de solo sob plantio direto e preparo convencional Variability and correlation among physical properties of an oxisol under no-till and conventional tillage

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    Valter Roberto Schaffrath


    Full Text Available Os sistemas de manejo do solo influenciam a distribuição espacial das propriedades físicas do solo. Os objetivos deste estudo foram verificar a dependência e a correlação espacial de algumas propriedades físicas do solo por meio do ajuste de dados aos semivariogramas simples e cruzados num Latossolo Vermelho distroférrico, sob plantio direto e preparo convencional, no município de Campo Mourão, Estado do Paraná. Em abril de 2004, realizou-se a amostragem de solo e retiraram-se 128 amostras de solo indeformadas, em malha de 3,0 x 5,0 m, no terço médio da camada de 0-0,15 m de profundidade. Foram determinadas as seguintes propriedades físicas do solo: densidade do solo, macroporosidade, microporosidade, porosidade total, e o conteúdo de água do solo na tensão de 100 hPa ou equivalente à capacidade de campo. Essas propriedades físicas do solo apresentaram semivariogramas simples com maior variabilidade espacial e menor alcance no plantio direto do que no preparo convencional. Contrariamente, os semivariogramas cruzados entre a densidade do solo com a porosidade total ou a capacidade de campo mostraram correlação espacial com menor variabilidade espacial e maior alcance no plantio direto, comparado ao preparo convencional. Os semivariogramas cruzados evidenciaram que a densidade do solo determinou as correlações espaciais com as outras propriedades físicas nos dois sistemas de manejo do solo.Soil management systems modify the spatial distribution of soil physical properties. The objectives of this study were to verify the spatial dependency and co-relationship of some soil physical properties by data fitting to individual and cross-semivariograms in an Oxisol (Typic Haplorthox under no-till and conventional tillage, in Campo Mourão, state of Parana, Brazil. In April 2004, 128 undisturbed soil samples were collected in a 3 x 5 m grid, in the middle of the 5-0.15 m layer. The following soil physical properties were measured

  14. Oxisol resistence to penetration in no-till system after sowing Resistência de um latossolo vermelho distroférrico à penetração em sistema plantio direto após semeadura

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    Vinicius de V Ros


    Full Text Available If inappropriately conducted, management and sowing practices may compromise the environment and the profitability of the agricultural activity. The aim of this study was to analyze the furrow opener mechanisms action and the level of load applied to soil firming mechanism in no-till, on the Oxisol resistance to penetration during soybean sowing, under three soil moistures. The experiment was arranged in split-split plot design, in which the plots were composed by three soil moistures (23.8; 25.5 and 27.5% b.s., two furrow opener mechanisms sub-plots (double disks and furrow plough and the split-split plot of three levels of load applied to soil firming mechanism (12.2; 18.5 and 24.1 kPa, according to randomized blocks design, with three replications. The soil moisture provided different resistance behavior to penetration with the depth, on the seedbed, independently of the furrow opener and the level of load applied to soil firming mechanism. The furrow plough use provided less soil resistance to penetration when compared to the double disk furrow opener, on the seedbed, independently of the soil moisture and the level of load applied to soil firming mechanism. The pressure applied by soil firming mechanism of 18.5 kPa provided the lower resistance to penetration, when the furrow plough was used. The soil resistance to penetration was less on the sowing line than on between rows, with 20 cm deep.Práticas de manejo e semeadura mal conduzidas podem comprometer o meio ambiente e a rentabilidade da atividade agrícola. O objetivo deste trabalho foi estudar a ação de mecanismos sulcadores e a pressão da roda compactadora de uma semeadora-adubadora em plantio direto, na resistência de um Latossolo Vermelho distroférrico à penetração (RP, durante a semeadura da soja, sob três teores de água do solo. O experimento foi desenvolvido em esquema de blocos casualizados, arranjado em esquema de parcelas subsubdivididas, sendo as parcelas constitu

  15. Acidification evidences of no-tilled soils of the central region of argentina Evidencias de acidificación de suelos de la región central de la argentina bajo siembra directa

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    Laura Antonela Iturri


    Full Text Available Empiric evidences indicate that agricultural soils of Argentina tend to acidify. The objective of this study was to determine the pH values of no-tilled and urea-fertilized-agricultural soils of Argentina during several years. Results indicated that both the actual pH (pH A and the potential pH (pH P values were lower in humid than in dry environments. The ratio between «mean annual precipitation:mean annual temperature» of the sites explained between 60 and 80% of the variability in pH values. This suggests that climatic conditions were responsible for current soil pH values. The pH A was 1.14 points higher tan pH P in all studied sites (pEvidencias empíricas indican que los suelos agrícolas de la Argentina tienden a la acidificación. El objetivo de este estudio fue determinar valores de pH de suelos agrícolas de la Argentina bajo siembra directa de larga duración y fertilización con urea. Los resultados indican que tanto los valores de pH actual (pH A como de pH potencial (pH P fueron más bajos en ambientes húmedos que en los más secos. El cociente entre «precipitación media anual : temperatura media anual» de los sitios explicó entre un 60 y un 80% de la variabilidad de los valores de pH. Esto sugiere que las condiciones climáticas fueron responsables de los valores de pH presentes en estos suelos. El pH A fue 1,14 puntos mayor que el pH P en todos los sitios estudiados (p < 0,01 indicando que existió un proceso natural generalizado de acidificación. En suelos de ambientes más secos, las diferencias entre el pH A y el pH P fueron, en promedio, mayores a 1,21. Esto indicaría una acidificación más intensa. Sin embargo, los valores de pH no fueron lo suficientemente bajos como para afectar el normal crecimiento de cultivos y de organismos del suelo. En suelos de ambientes húmedos, las diferencias entre el pH A y el pH P fueron superiores a 1,10, siendo los valores de pH A (6,17 and 5,80 lo suficientemente ácidos como para

  16. Metolachlor e fomesafen aplicados via irrigação por aspersão em plantio direto e convencional Metolachlor and fomesafen applied via sprinkler irrigation under conventional and no-till systems

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    J.R.A. Fontes


    herbicides were also sprayed. Two checks were included: with and without weeds. The predominant weed in the no-till system was Bidens pilosa and in the conventional tillage, Artemisia verlotorum. In general, herbigation was more efficient than spray for weed control, regardless of the type of tillage system. Water volume of 5 or 10 mm for metolachlor, and 3 or 6 mm for fomesafen, yielded the best results, overall.

  17. Spatial distribution of Pseudaletia sequax Franclemlont in triticale under no-till management Distribuição espacial de Pseudaletia sequax Franclemont na cultura do triticale, em plantio direto

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    Célia Regina Grego


    Full Text Available The knowledge of the spatial distribution of insect populations in crops allows the estimation of the population density in space, the classification of damage impact on yield as well as decisions to be made about control measures. To evaluate the spatial distribution of the wheat armyworm Pseudaletia sequax Franclemont, in relation to the development and yield of triticale (Triticum secale Wittmack under no-till management, samplings were taken at 302 points in a square grid measuring 10 x 10 m, in Campinas, SP, Brazil. The caterpillar population was evaluated by counting their number per meter at the base of triticale plants. Grain yield (kg ha-1, cover of the above-ground part (kg ha-1, mean plant height (m, and ground cover percentage were evaluated after the triticale crop was mechanically harvested, with the measurement of the mass of straw left on soil surface. Geostatistics was used to analyze spatial variability, by means of semivariogram analysis, and interpolation of data by both ordinary and indicator kriging, considering the injury threshold level of ten caterpillars per square meter to construct isoline maps. Spatial dependence occurred for all variables, demonstrating an aggregate spatial distribution pattern of the caterpillar in triticale. Random sampling in this area would fail to reveal that grain yield was affected at the location with the greatest occurrence of the caterpillar. At that location, the economic injury level was exceeded, which would justify the adoption of control measures against the pest.O conhecimento da distribuição espacial de populações de insetos de uma cultura permite estimar a densidade populacional no espaço, classificar seus danos causados à produção e tomar uma decisão sobre a medida de controle. Assim, este trabalho foi desenvolvido com o objetivo de avaliar a distribuição espacial da lagarta do trigo Pseudaletia sequax Franclemont, em relação ao desenvolvimento e produção do

  18. The ecology of sandy beaches in Transkei

    African Journals Online (AJOL)

    The ecology of sandy beaches in Transkei. T. Wooldridge, A.H. Dye and A. Mclachlan. Department of Zoology, University of Port Elizabeth, Port Elizabeth. Data from an ecological survey of three sandy beaches in. Transkei and from Gulu beach on the eastern Cape coast,. South Africa, are presented. Physical parameters ...

  19. The ecology of sandy beaches in Natal

    African Journals Online (AJOL)

    The ecology of sandy beaches in Natal. A.H. Dye, A. Mclachlan and T. Wooldridge. Department of Zoology, University of Port Elizabeth, Port Elizabeth. Data from an ecological survey of four sandy beaches on the. Natal coast of South Africa are presented. Physical para· meters such as beach profile, particle size, moisture, ...

  20. Measurement of biological oxygen demand sandy beaches

    African Journals Online (AJOL)

    Measurement of biological oxygen demand sandy beaches. •. In. A.H. Dye. Measurements of biological oxygen demand in a sandy beach using conventional in situ techniques are compared with laboratory measurements of interstitial oxygen changes in intact cores. Oxygen uptake as measured in the laboratory was ...

  1. Liming and Ionic speciation of an Oxisol under no-till system Calagem e especiação iônica de um Latossolo sob sistema plantio direto

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    Fernando Cesar Bachiega Zambrosi


    Full Text Available The chemical speciation of the soil solution is an important tool for evaluating nutrient availability and aluminum phytotoxicity. The effect of liming in the composition of the soil solution under the no-till (NT system is still not well known. We evaluated the chemical speciation of Al and nutrients in the soil solution (water extract 1:1, five years after liming at the moment of the establishment of NT in a native pasture, in Ponta Grossa, Paraná State, Brazil. Dolomitic lime was applied at a rate of 4.5 t ha-1 (either incorporated or surface-applied, or split in three annual rates of 1.5 t ha-1. Soil samples from a dystrophic clayey Rhodic Hapludox were collected at the 0 - 0.05; 0.05 - 0.1; 0.1 - 0.2; 0.2 - 0.4; 0.4 - 0.6; and 0.6 - 0.8 m layers, in May, 2003. Aluminum was mainly complexed to dissolved organic carbon (DOC and fluoride, while the free form Al3+ was present in fewer amounts even under acidic conditions. Calcium and magnesium were found as free forms (Ca2+, Mg2+ and complexed by organic anions. Phosphorus was found as free forms (HPO4(2-, H2PO4- and complexed with aluminum (ionic pair Al-HxPO4x up to 0.1 m. Complexation of Al by DOC was not influenced by surface-applied or incorporated liming. Liming did not change Ca and Mg speciation in the soil solution under NT system. The presence of free forms HPO4(2- and H2PO4-, however, was influenced by liming, because of the increase in cation associated forms.A especiação química da solução do solo é uma importante ferramenta para avaliar a disponibilidade de nutrientes e o potencial fitotóxico do alumínio. As formas em que os elementos ocorrem na solução dos solos sob sistema plantio direto (SPD ainda são pouco conhecidas, sobretudo em áreas que receberam aplicação de calcário. Avaliou-se a distribuição das espécies químicas de alumínio e nutrientes na solução do solo (extrato aquoso 1:1, cinco anos após a aplicação de calcário, na introdução do SPD em


    Directory of Open Access Journals (Sweden)

    JJ Siang


    Full Text Available Hill's code is one of text encoding technique. In this research, Hill's code is extended to image encoding. The image used is BMP 24 bit format. 2x2 and 3x3 matrices is used as a key. The results show that Hill's code is suitable for image whose RGB values vary highly. On the contrary, it is not suitable for less varied RGB images since its original pattern is still persisted in encrypted image. Hill's code for image encoding has also disadvantage in the case that the key matrix is not unique. However, for daily application, with good key matrix, Hill's code can be applied to encode image since it's process only deals with simple matrix operation so it become fast. Abstract in Bahasa Indonesia : Sandi Hill merupakan salah satu teknik penyandian teks. Dalam penelitian ini, pemakaian sandi Hill diperluas dari teks ke citra bertipe BMP 24 bit. Matriks yang dipakai berordo 2x2 dan 3x3. Hasil percobaan menunjukkan bahwa sandi Hill cocok untuk enkripsi citra dengan variasi nilai RGB antar piksel berdekatan yang tinggi (seperti foto, tapi tidak cocok untuk citra dengan variasi nilai RGB yang rendah (seperti gambar kartun karena pola citra asli masih tampak dalam citra sandi. Sandi Hill juga memiliki kelemahan dalam hal tidak tunggalnya matriks kunci yang dapat dipakai. Akan tetapi untuk pemakaian biasa, dengan pemilihan matriks kunci yang baik, sandi Hill dapat dipakai untuk penyandian karena hanya melibatkan operasi matriks biasa sehingga prosesnya relatif cepat. Kata kunci: Sandi Hill, Citra, Relatif Prima.

  3. Atributos químicos e perfil de enraizamento de milho influenciados pela calagem em semeadura direta Chemical attributes and corn root system development as affected by liming in no-till

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    Gabriel Henrique Melo Nascimento Leite


    ,20-0,30 m. Mesmo sob condições químicas adversas, em todos os tratamentos, o milho apresentou crescimento de raízes até 0,45 m de profundidade. O tratamento 100I apresentou maior crescimento de raízes até 0,15-0,20 m de profundidade do que os tratamentos com doses menores de calcário em superfície (50S e 25S, onde as raízes se concentraram na camada até 0,075 m. A incorporação do calcário proporcionou maior uniformidade na neutralização da acidez do solo em profundidade, o que se refletiu em maior quantidade de raízes até 0,45 m.In Rio Grande do Sul state, the area cultivated with under no-till system now amounts to 60 % of the total rain-fed cultivated area. However, there are still doubts as to crop practices in this soil conservation system, such as liming and fertilization as well as regarding root growth and crop productivity. The objective of this study was to evaluate the effects of lime doses and application forms on corn root development. The experiment was carried out in 1999/2000, in the experimental area of the Soil Science Department of the Federal University of Santa Maria, state of Rio Grande do Sul, Brazil, in a random block design in split plots, with four replications. The soil under study was a typical Hapludalf with 2 % slope. Main treatments were: no lime (SC, incorporation of 100 % of the recommended dose (100I, and 25 % (25S, 50 % (50S and 100 % (100S of the recommended dose (6.8 t ha-1 distributed over the soil surface. Lime was incorporated with conventional tillage in February 1996. Using the "nail board" method, with dimensions of 0,20 x 0,30 m, 0,30 x 0,45 m and 0,45 x 0,70 m, monoliths were taken from the soil profile, parallel to the corn sowing furrow, at 20, 54 and 80 days after corn emergence (DAE. The monoliths were carefully washed and the roots counted to establish a corn rooting profile in each treatment. Increasing lime doses applied on the soil surface (25S, 50S and 100S increased the depth at which elevations in p

  4. Ammonia volatilization in no-till system in the south-central region of the State of Paraná, Brazil Volatilização de amônia em plantio direto na região centro-sul do Paraná

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    Sandra Mara Vieira Fontoura


    Full Text Available Ammonia (NH3 volatilization can reduce the efficiency of urea applied to the surface of no-till (NT soils. Thus, the objectives of this study were to evaluate the magnitude of NH3 losses from surface-applied urea and to determine if this loss justifies the urea incorporation in soil or its substitution for other N sources under the subtropical climatic conditions of South-Central region of Paraná State, Brazil. The experiment, performed over four harvesting seasons in a clayey Hapludox followed a randomized block design with four replicates. A single dose of N (150 kg ha-1 to V5 growth stage of corn cultivated under NT system was applied and seven treatments were evaluated, including surface-applied urea, ammonium sulfate, ammonium nitrate, urea with urease inhibitor, controlled-release N source, a liquid N source, incorporated urea, and a control treatment with no N application. Ammonia volatilization was evaluated for 20 days after N application using a semi-open static system. The average cumulative NH3 loss due to the superficial application of urea was low (12.5 % of the applied N compared to the losses observed in warmer regions of Southeastern Brazil (greater than 50 %. The greatest NH3 losses were observed in dry years (up to 25.4 % of the applied N, and losses decreased exponentially as the amount of rainfall after N application increased. Incorporated urea and alternative N sources, with the exception of controlled-release N source, decreased NH3 volatilization in comparison with surface-applied urea. Urea incorporation is advantageous for the reduction of NH3 volatilization; however, other aspects as its low operating efficiency should be considered before this practice is adopted. In the South-Central region of Paraná, the low NH3 losses from the surface-applied urea in NT system due to wet springs and mild temperatures do not justify its replacement for other N sources.A volatilização de amônia (NH3 pode resultar em baixa efici

  5. Heterotrophic bacterial populations in tropical sandy beaches

    Digital Repository Service at National Institute of Oceanography (India)

    Nair, S.; LokaBharathi, P.A.

    Distribution pattern of heterotrophic bacterial flora of three sandy beaches of the west coast of India was studied. The population in these beaches was microbiologically different. Population peaks of halotolerant and limnotolerant forms were...

  6. EAARL Coastal Topography-Sandy Hook 2007 (United States)

    U.S. Geological Survey, Department of the Interior — A first surface/bare earth elevation map (also known as a Digital Elevation Model, or DEM) of the Gateway National Recreation Area's Sandy Hook Unit in New Jersey...

  7. Satellite Observations Monitor Outages From Superstorm Sandy (United States)

    Molthan, Andrew; Jedlovec, Gary


    In late October 2012, Hurricane Sandy traveled across Jamaica, Cuba, and the Bahamas, then progressed northward along the eastern seaboard of the United States, resulting in numerous tropical storm warnings along the coasts of Florida and North Carolina. As the storm approached the Mid-Atlantic region, interaction with an upper-level low drew the cyclone inland, with the center passing just north of Atlantic City, N. J. In what media reports dubbed a "superstorm," Sandy produced hurricane-force winds, significant coastal storm surge, torrential rain, inland flooding, and extensive damage over a vast area. Further west of the cyclone center, strong winds increased wave activity throughout the Great Lakes, and heavy snowfall occurred across portions of Tennessee, Kentucky, and West Virginia. As of early November, more than 100 fatalities had been attributed to Sandy in the northeastern United States, with total economic losses of up to $50 billion [New York Times, 2012, and Walsh and Schwartz, 2012].

  8. Operational Group Sandy technical progress report (United States)



    Hurricane Sandy made US landfall near Atlantic City, NJ on 29 October 2012, causing 72 direct deaths, displacing thousands of individuals from damaged or destroyed dwellings, and leaving over 8.5 million homes without power across the northeast and mid-Atlantic. To coordinate federal rebuilding activities in the affected region, the President established the cabinet-level Hurricane Sandy Rebuilding Task Force (Task Force). The Task Force was charged with identifying opportunities for achieving rebuilding success while supporting economic vitality, improving public health and safety, protecting and enhancing natural and manmade infrastructure, bolstering resilience, and ensuring appropriate accountability.

  9. Indicadores biológicos associados ao ciclo do fósforo em solos de Cerrado sob plantio direto e plantio convencional Soil biological indicators associated to the phosphorus cycle in a Cerrado soil under no-till and conventional tillage systems

    Directory of Open Access Journals (Sweden)

    Roberto Guimarães Carneiro


    Full Text Available O objetivo deste trabalho foi avaliar a influência do plantio direto, do preparo convencional do solo e de plantas de cobertura sobre indicadores biológicos associados ao ciclo do fósforo (P. O trabalho foi realizado em três áreas adjacentes, num Latossolo Vermelho-Amarelo, distribuídas da seguinte maneira: área I, dois anos de experimentação, comparando esses sistemas de plantio; área II, seis anos de experimentação e área III, Cerrado nativo. Em julho/1998 e janeiro/1999, avaliaram-se: o P da biomassa, populações de fungos e bactérias totais e solubilizadores de fosfato e a atividade da fosfatase ácida, nas profundidades de 0-5 e de 5-20 cm. A atividade da fosfatase e a ocorrência de fungos e bactérias solubilizadoras nas áreas com plantio direto foram significativamente superiores às das áreas com plantio convencional, na profundidade de 0-5 cm. O tempo de implantação acentuou as diferenças entre plantio direto e convencional quanto aos indicadores avaliados. O P da biomassa diminuiu no tratamento plantio direto com nabo forrageiro (Raphanus sativus da área II. Os fungos solubilizadores aumentaram na presença de guandu (Cajanus cajan e nabo forrageiro, e as bactérias solubilizadoras aumentaram na presença de guandu. O solo sob vegetação nativa apresentou maior atividade da fosfatase em relação ao das áreas cultivadas, evidenciando a importância da mineralização do P orgânico nesse ecossistema.The objective of this work was to evaluate the effects of no-till, conventional tillage and cover crops on biological indicators associated to the P cycle. The work was carried out on three adjacent areas on a Red-Yellow Oxisol: area I, a two-year experiment comparing the two management systems; area II, a six-year experiment, and area III, a native Cerrado vegetation. The soil was sampled at two depths (0-5 cm and 5-20 cm in July/1998 and January/1999. The biological indicators evaluated were microbial biomass P

  10. Modelling the morphology of sandy spits

    DEFF Research Database (Denmark)

    Pedersen, Dorthe; Deigaard, Rolf; Fredsøe, Jørgen


    The shape, dimensions and growth rate of an accumulating sandy spit is investigated by a theoretical and experimental study. The idealised case of a spit growing without change of form under a constant wave forcing is considered. The longshore wave-driven sediment transport is taken to be dominan...

  11. Post-Sandy, Schools Claw Back (United States)

    Maxwell, Lesli A.


    David Weiss, the superintendent in Long Beach, N.Y., wrestled with a slew of considerations last week as he weighed when to restart school, nine days after Hurricane Sandy wrecked his community. Just one of seven buildings had most of the essentials: electricity, heat, working fire alarms, sewage, and food. And, with many students and staff…

  12. Coastal ocean circulation during Hurricane Sandy (United States)

    Miles, Travis; Seroka, Greg; Glenn, Scott


    Hurricane Sandy (2012) was the second costliest tropical cyclone to impact the United States and resulted in numerous lives lost due to its high winds and catastrophic storm surges. Despite its impacts little research has been performed on the circulation on the continental shelf as Sandy made landfall. In this study, integrated ocean observing assets and regional ocean modeling were used to investigate the coastal ocean response to Sandy's large wind field. Sandy's unique cross-shelf storm track, large size, and slow speed resulted in along-shelf wind stress over the coastal ocean for nearly 48 h before the eye made landfall in southern New Jersey. Over the first inertial period (˜18 h), this along-shelf wind stress drove onshore flow in the surface of the stratified continental shelf and initiated a two-layer downwelling circulation. During the remaining storm forcing period a bottom Ekman layer developed and the bottom Cold Pool was rapidly advected offshore ˜70 km. This offshore advection removed the bottom Cold Pool from the majority of the shallow continental shelf and limited ahead-of-eye-center sea surface temperature (SST) cooling, which has been observed in previous storms on the MAB such as Hurricane Irene (2011). This cross-shelf advective process has not been observed previously on continental shelves during tropical cyclones and highlights the need for combined ocean observing systems and regional modeling in order to further understand the range of coastal ocean responses to tropical cyclones.

  13. Lessons from Hurricane Sandy for port resilience. (United States)


    New York Harbor was directly in the path of the most damaging part of Hurricane Sandy causing significant impact on many of the : facilities of the Port of New York and New Jersey. The U.S. Coast Guard closed the entire Port to all traffic before the...

  14. Bibliography of sandy beaches and sandy beach organisms on the African continent

    CSIR Research Space (South Africa)

    Bally, R


    Full Text Available This bibliography covers the literature relating to sandy beaches on the African continent and outlying islands. The bibliography lists biological, chemical, geographical and geological references and covers shallow marine sediments, surf zones off...

  15. Methane Fluxes from Subtropical Wetlands (United States)

    DeLucia, N.; Gomez-Casanovas, N.; Bernacchi, C.


    It is well documented that green house gas concentrations have risen at unequivocal rates since the industrial revolution but the disparity between anthropogenic sources and natural sources is uncertain. Wetlands are one example of a natural ecosystem that can be a substantial source or sink for methane (CH4) depending on climate conditions. Due to strict anaerobic conditions required for CH4-generating microorganisms, natural wetlands are one of the main sources for biogenic CH4. Although wetlands occupy less than 5% of total land surface area, they contribute approximately 20% of total CH4 emissions to the atmosphere. The processes regulating CH4 emissions are sensitive to land use and management practices of areas surrounding wetlands. Variation in adjacent vegetation or grazing intensity by livestock can, for example, alter CH4 fluxes from wetland soils by altering nutrient balance, carbon inputs and hydrology. Therefore, understanding how these changes will affect wetland source strength is essential to understand the impact of wetland management practices on the global climate system. In this study we quantify wetland methane fluxes from subtropical wetlands on a working cattle ranch in central Florida near Okeechobee Lake (27o10'52.04'N, 81o21'8.56'W). To determine differences in CH4 fluxes associated with land use and management, a replicated (n = 4) full factorial experiment was designed for wetlands where the surrounding vegetation was (1) grazed or un-grazed and (2) composed of native vegetation or improved pasture. Net exchange of CH4 and CO2 between the land surface and the atmosphere were sampled with a LICOR Li-7700 open path CH4 analyzer and Li-7500A open path CO2/H20 analyzer mounted in a 1-m3 static gas-exchange chamber. Our results showed and verified that CH4 emissions from subtropical wetlands were larger when high soil moisture was coupled with high temperatures. The presence of cattle only amplified these results. These results help quantify

  16. Nitrate role in basic cation leaching under no-till

    Directory of Open Access Journals (Sweden)

    Carlos Alexandre Costa Crusciol


    Full Text Available Especially under no-tillage, subsuface soil acidity has been a problem, because it depends on base leaching, which has been associated with the presence of low molecular weigth organic acids and companion anions. The objective of this study was to evaluate exchangeable base cation leaching as affected by surface liming along with annual urea side-dressing of maize and upland rice. Treatments consisted of four lime rates (0, 1500, 3000, and 6000 kg ha-1 combined with four nitrogen rates (0, 50, 100, and 150 kg ha-1 applied to maize (Zea mays and upland rice (Oryza sativa, in two consecutive years. Maize was planted in December, three months after liming. In September of the following year, pearl millet (Pennisetum glaucum was planted without fertilization and desiccated 86 days after plant emergence. Afterwards, upland rice was grown. Immediately after upland rice harvest, 18 months after surface liming, pH and N-NO3-, N-NH4+, K, Ca, and Mg levels were evaluated in soil samples taken from the layers 0-5, 5-10, 10-20 and 20-40 cm. Higher maize yields were obtained at higher N rates and 3000 kg ha-1 lime. Better results for upland rice and pearl millet yields were also obtained with this lime rate, irrespective of N levels. The vertical mobility of K, Ca and Mg was higher in the soil profiles with N fertilization. Surface liming increased pH in the upper soil layers causing intense nitrate production, which was leached along with the base cations.

  17. Influência do preparo inicial sobre a estrutura do solo quando da adoção do sistema plantio direto, avaliada por meio da pressão de preconsolidação Influence of initial tillage operations on the soil structure appraised through the preconsolidation pressure when adopting the no till system

    Directory of Open Access Journals (Sweden)

    R. B. Silva


    ência, isto é, para a melhoria da estrutura do solo nas profundidades SP e PMT, respectivamente, quando da adoção do sistema plantio direto.Little research has yet been done into the effects of traffic and tillage operations on agricultural soil structures of the Cerrado region before and during the implantation of no till systems. However, the developed studies are only qualitative and usually use properties such as soil bulk density and penetration resistance. These variables cannot predict the pressure the soil can withstand so that soil compaction through future soil management could be avoided. The objective of this work was to evaluate the influence of the initial tillage operations at the adoption of the no till system on the soil structure of a dystrophic Red Latosol through the preconsolidation pressure (sigmap. The sigmap values were obtained from soil compressibility models, which take the influence of the following factors into consideration: (1 initial tillage operations: moldboard plow (AA, disk plow (AD disk harrow (GA and vibrosubsoiler (VS; (2 soil management: conventional till (PC which was used as a reference to evaluate the influence of the tillage operations; and (3 depth: Surface layer (SP - 0.00 to 0.05 m and medium work depth of the tillage implement (PMT - 0.24 to 0.27 m. Results evidenced that the sigmap was efficient at the evaluation of the initial tillage operations when implanting the no till system in the dystrophic Red Latosol, with its varying values according to tillage operation and depth. The sigmap evidenced a larger mechanical resistance and, therefore, larger soil consolidation of the soil structure at SP depth of the area under no till. It was also verified that the appraised initial tillage operations reduced the soil mechanical resistance at the PMT depth, compared to the conventional tillage system. However, the vibrosubsolador and the disk plow are the recommended tillage tools to relieve this soil resistance, that is, to improve

  18. Acidification of sandy grasslands - consequences for plant diversity

    DEFF Research Database (Denmark)

    Olsson, Pål Axel; Mårtensson, Linda-Maria; Bruun, Hans Henrik


    Questions: (1) Does soil acidification in calcareous sandy grasslands lead to loss of plant diversity? (2) What is the relationship between the soil content of lime and the plant availability of mineral nitrogen (N) and phosphorus (P) in sandy grasslands? Location: Sandy glaciofluvial deposits...... in south-eastern Sweden covered by xeric sand calcareous grasslands (EU habitat directive 6120). Methods: Soil and vegetation were investigated in most of the xeric sand calcareous grasslands in the Scania region (136 sample plots distributed over four or five major areas and about 25 different sites...... of soil P, placing a major constraint on primary productivity in sandy soils. Conclusions: Acidification of sandy grasslands leads to reduced abundance of desirable species, although the overall effect is rather weak between pH 5 and pH 9. Slopes are important for high diversity in sandy grasslands...

  19. The Effect of Tillage System and Crop Rotation on Soil Microbial Diversity and Composition in a Subtropical Acrisol

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    Eric W. Triplett


    Full Text Available Agricultural management alters physical and chemical soil properties, which directly affects microbial life strategies and community composition. The microbial community drives important nutrient cycling processes that can influence soil quality, cropping productivity and environmental sustainability. In this research, a long-term agricultural experiment in a subtropical Acrisol was studied in south Brazil. The plots at this site represent two tillage systems, two nitrogen fertilization regimes and three crop rotation systems. Using Illumina high-throughput sequencing of the 16S rRNA gene, the archaeal and bacterial composition was determined from phylum to species level in the different plot treatments. The relative abundance of these taxes was correlated with measured soil properties. The P, Mg, total organic carbon, total N and mineral N were significantly higher in the no-tillage system. The microbial diversity was higher in the no-tillage system at order, family, genus and species level. In addition, overall microbial composition changed significantly between conventional tillage and no-tillage systems. Anaerobic bacteria, such as clostridia, dominate in no-tilled soil as well as anaerobic methanogenic archaea, which were detected only in the no-tillage system. Microbial diversity was higher in plots in which only cereals (oat and maize were grown. Soil management influenced soil biodiversity on Acrisol by change of composition and abundance of individual species.

  20. Sorção do herbicida acetochlor em amostras de solo, ácidos húmicos e huminas de argissolo submetido à semeadura direta e ao preparo convencional Sorption of acetochlor herbicide by soil samples, humic acids and humin from an argisol under no-till and conventional tillage systems

    Directory of Open Access Journals (Sweden)

    Miguel Vicente Weiss Ferri


    Full Text Available A sorção de herbicidas no solo é um dos processos determinantes na sua dinâmica no ambiente. Para compostos fracamente polares, como é caso do acetochlor, a matéria orgânica do solo constitui o principal sorvente. O objetivo deste estudo foi avaliar a sorção de acetochlor em amostras de solo, de ácidos húmicos e de huminas de um Argissolo Vermelho distrófico (PVd submetido à semeadura direta e ao preparo convencional. Isotermas de sorção foram obtidas em temperatura ambiente e a concentração do herbicida foi determinada por cromatografia líquida de alta eficiência. As amostras de solo foram caracterizadas pelos teores de C orgânico e de substâncias húmicas; os ácidos húmicos e huminas foram caracterizados por análise elementar. A capacidade de sorção de acetochlor foi superior no solo de semeadura direta (Kd = 1,22 ± 0,11 L kg-1, K OC = 116 ± 10 L kg-1 C em relação ao preparo convencional (Kd = 0,76 ± 0,08 L kg-1, K OC = 86 ± 8 L kg-1 C. Este comportamento foi relacionado, em parte, com o maior teor de C no solo tratado com semeadura direta. Nos ácidos húmicos de preparo convencional, a sorção (Kd = 178 ± 18,9 L kg-1, K OC = 352 ± 37 L kg-1C foi similar à verificada nos ácidos húmicos de semeadura direta (Kd = 158 ± 14,6 L kg-1, K OC = 321 ± 30 L kg-1 C; situação semelhante foi observada com as huminas. Dentre as frações húmicas avaliadas, as huminas apresentaram maior capacidade de sorção (Kd = 1.028 e 1.183 L kg-1, K OC = 2.691 e 2.892 L kg-1 C.The sorption of herbicides to soil is a process determinant of its dynamics in the environment. For weakly polar compounds such as acetochlor, organic matter represents the main sorbent in soil. The goal of this study was to evaluate the sorption of acetochlor on soil samples, humic acids and humin from an "Argissolo Vermelho distrófico" (PVd-Paleudult under no-till and conventional tillage systems. Sorption isotherms were carried out at room

  1. Epidemic gasoline exposures following Hurricane Sandy. (United States)

    Kim, Hong K; Takematsu, Mai; Biary, Rana; Williams, Nicholas; Hoffman, Robert S; Smith, Silas W


    Major adverse climatic events (MACEs) in heavily-populated areas can inflict severe damage to infrastructure, disrupting essential municipal and commercial services. Compromised health care delivery systems and limited utilities such as electricity, heating, potable water, sanitation, and housing, place populations in disaster areas at risk of toxic exposures. Hurricane Sandy made landfall on October 29, 2012 and caused severe infrastructure damage in heavily-populated areas. The prolonged electrical outage and damage to oil refineries caused a gasoline shortage and rationing unseen in the USA since the 1970s. This study explored gasoline exposures and clinical outcomes in the aftermath of Hurricane Sandy. Prospectively collected, regional poison control center (PCC) data regarding gasoline exposure cases from October 29, 2012 (hurricane landfall) through November 28, 2012 were reviewed and compared to the previous four years. The trends of gasoline exposures, exposure type, severity of clinical outcome, and hospital referral rates were assessed. Two-hundred and eighty-three gasoline exposures were identified, representing an 18 to 283-fold increase over the previous four years. The leading exposure route was siphoning (53.4%). Men comprised 83.0% of exposures; 91.9% were older than 20 years of age. Of 273 home-based calls, 88.7% were managed on site. Asymptomatic exposures occurred in 61.5% of the cases. However, minor and moderate toxic effects occurred in 12.4% and 3.5% of cases, respectively. Gastrointestinal (24.4%) and pulmonary (8.4%) symptoms predominated. No major outcomes or deaths were reported. Hurricane Sandy significantly increased gasoline exposures. While the majority of exposures were managed at home with minimum clinical toxicity, some patients experienced more severe symptoms. Disaster plans should incorporate public health messaging and regional PCCs for public health promotion and toxicological surveillance.

  2. Rediscovering Community—Reflections After Hurricane Sandy


    See, Sharon


    Hoboken, New Jersey, is a town of 50,000 residents located across the Hudson River from New York City. Most of Hoboken’s infrastructure was compromised during Hurricane Sandy as a result of flooding and power outages that rendered many businesses inoperable, including all of the pharmacies in town. Despite a focus on emergency preparedness since Hurricane Katrina and 9/11, there were no contingencies in place to facilitate and assess the medication needs of the community in the event of a nat...

  3. Dynamics of ecosystem services provided by subtropical ... (United States)

    The trends in the provision of ecosystem services during restoration and succession of subtropical forests and plantations were quantified, in terms of both receiver and donor values, based on a case study of a 3-step secondary succession series that included a 400-year-old subtropical forest and a 23-year history of growth on 3 subtropical forest plantations in Southeastern China. The ‘People's Republic of China Forestry Standard: Forest Ecosystem Service Valuation Norms’ was revised and applied to quantify the receiver values of ecosystem services, which were then compared with the emergy-based, donor values of the services. The results revealed that the efficiencies of subtropical forests and plantations in providing ecosystem services were 2 orders of magnitude higher than similar services provided by the current China economic system, and these efficiencieskept increasing over the course of succession. As a result, we conclude that afforestation is an efficient way to accelerate both the ability and efficiency of subtropical forests to provide ecosystem services. This paper is significant because it examines the dynamics of the provision of ecosystem services by forests over a succession series that spans 400 years. The paper also examines the rate of increase of services during forest restoration over a period of 23 years. The emergy used in ecosystem services provision is compared to the provision of similar services by economic means in the Chinese e

  4. Estratégias de manejo de coberturas de solo no inverno para cultivo do milho em sucessão no sistema semeadura direta Management strategies of winter cover crops to maize grown in succession in no-till system

    Directory of Open Access Journals (Sweden)

    Paulo Regis Ferreira da Silva


    Full Text Available A maioria dos produtores do estado do Rio Grande do Sul adota o sistema de semeadura direta, em que não há revolvimento do solo para preparo da área para semeadura. A adoção de um sistema de rotação e sucessão de culturas diversificado, que produza adequada quantidade de resíduos culturais na superfície do solo, é fundamental para sustentabilidade do sistema de semeadura direta. Os agricultores dispõem de várias espécies de cobertura de solo no inverno com potencial para anteceder a cultura do milho em sucessão. Na família das poáceas, destaca-se a aveia preta (Avena strigosa como a mais cultivada. No entanto, o seu uso continuado pode causar prejuízos ao cultivo do milho em sucessão. Objetivando minimizar os efeitos das poáceas e ao mesmo tempo atender às exigências do sistema de semeadura direta, novas espécies de inverno pertencentes a famílias botânicas distintas, como fabáceas e brassicáceas, têm sido estudadas, tanto em cultivos solteiros quanto em consórcio com poáceas, como alternativas para anteceder o cultivo do milho. Assim, esta revisão bibliográfica tem como objetivos descrever as principais vantagens e limitações do uso de coberturas de solo no inverno, em cultivos solteiros ou consorciados, como culturas antecessoras ao milho no sistema de semeadura direta e discutir estratégias de manejo destas coberturas que resultem em maiores benefícios para o milho.The no-tillage system is adopted by most of the farmers in Rio Grande do Sul, Southern Brazil. No-till system requires no ploughing and only a narrow and superficial band or slot is opened in the soil to allow sowing. The sustainability of this system is dependent on a diversified system of crop rotation and succession able to leave on the soil an adequate amount of crop residues. In Rio Grande do Sul black oat (Avena strigosa L. is the most cultivated cover crop, in spite of fact that different cover crops are available to precede the maize crop

  5. Variabilidade espacial do pH, teores de matéria orgânica e micronutrientes em profundidades de amostragem num Latossolo Vermelho sob semeadura direta Space variability of the pH values, contents of organic matter and micronutrients in samplings depth in a Acrustox under no-till system

    Directory of Open Access Journals (Sweden)

    Luiz Antônio Zanão Júnior


    Full Text Available A variabilidade espacial dos índices de fertilidade do solo aumenta com a semeadura direta, constatando-se diferenças nos teores de nutrientes de uma camada superficial do solo em relação à outra logo abaixo. Disto, resulta a necessidade de definir novos procedimentos de amostragem para contemplar essas alterações. Com o objetivo de avaliar a variabilidade espacial do pH em água, teores de matéria orgânica e os micronutrientes boro (B, cobre (Cu, ferro (Fe, manganês (Mn e zinco (Zn, desenvolveu-se este trabalho num Latossolo Vermelho distrófico, textura muito argilosa, cultivado desde 1995 sob semeadura direta, em Uberlândia - MG. A coleta das amostras do solo foi realizada em intervalos regulares de 50m, em malha regular de 121 pontos, em três profundidades (0-10cm, 10-20cm e 0-20cm. Os dados foram avaliados por estatística descritiva e geoestatística, com base no ajuste de semivariogramas. Maiores teores de matéria orgânica, Mn e Zn foram verificados nos primeiros 10cm do solo, enquanto que, para Fe, os maiores teores ocorreram na camada de 10-20cm. As maiores variabilidades horizontais foram encontradas para B e as menores para pH em água. Para os atributos que apresentaram dependência espacial, esta foi classificada como moderada ou forte. A maioria dos dados se ajustou ao semivariograma de modelo exponencial, seguido do esférico e do linear. Apenas a variável zinco, na profundidade de 0-20cm, não apresentou dependência espacial. Os resultados obtidos devem ser considerados na definição de planos de amostragem do solo e no manejo da adubação da área em questão, através da análise do alcance e das variabilidades horizontal e vertical dos atributos químicos estudados.The space variability of the indexes of fertility of the soil increases with the no-till system, being verified differences in the nutrients contents of a superficial layer of the soil in relation to the other lower layer. Therefore, it requires

  6. Correlation between landscape fragmentation and sandy desertification: a case study in Horqin Sandy Land, China. (United States)

    Ge, Xiaodong; Dong, Kaikai; Luloff, A E; Wang, Luyao; Xiao, Jun; Wang, Shiying; Wang, Qian


    The exact roles of landscape fragmentation on sandy desertification are still not fully understood, especially with the impact of different land use types in spatial dimension. Taking patch size and shape into consideration, this paper selected the Ratio of Patch Size and the Fractal Dimension Index to establish a model that reveals the association between the area of bare sand land and the fragmentation of different land use types adjacent to bare sand land. Results indicated that (1) grass land and arable land contributed the most to landscape fragmentation processes in the regions adjacent to bare sand land during the period 1980 to 2010. Grass land occupied 54 % of the region adjacent to bare sand land in 1980. The Ratio of Patch Size of grass land decreased from 1980 to 2000 and increased after 2000. The Fractal Dimension Index of grass increased during the period 1980 to 1990 and decreased after 1990. Arable land expanded significantly during this period. The Ratio of Patch Size of arable land increased from 1980 to 1990 and decreased since 1990. The Fractal Dimension Index of arable land increased from 1990 to 2000 and decreased after 2000. (2) The Ratio of Patch Size and the Fractal Dimension Index were significantly related to the area of bare sand land. The role of landscape fragmentation was not linear to sandy desertification. There were both positive and negative effects of landscape fragmentation on sandy desertification. In 1980, the Ratio of Patch Size and the Fractal Dimension Index were negatively related to the area of bare sand land, showing that the landscape fragmentation and regularity of patches contributed to the expansion of sandy desertification. In 1990, 2000, and 2010, the Ratio of Patch Size and the Fractal Dimension Index were mostly positively related to the area of bare sand land, showing the landscape fragmentation and regularity of patches contributed to the reversion of sandy desertification in this phase. The absolute values of

  7. Nitrogen application timing and soil inorganic nitrogen dynamics under no-till oat/maize sequential cropping Época de aplicação de nitrogênio e din��mica do nitrogênio inorgânico do solo no sistema de culturas aveia/milho sob plantio direto

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    Jeferson Dieckow


    Full Text Available The timing of N application to maize is a key factor to be considered in no-till oat/maize sequential cropping. This study aimed to evaluate the influence of pre-planting, planting and sidedress N application on oat residue decomposition, on soil N immobilisation and remineralisation and on N uptake by maize plants in no-till oat/maize sequential cropping. Undisturbed soil cores of 10 and 20 cm diameter were collected from the 0-15 cm layer of a no-till Red Latossol, when the oat cover crop was in the milk-grain stage. Two greenhouse experiments were conducted simultaneously. Experiment A, established in the 10 cm diameter cores and without plant cultivation, was used to asses N dynamics in soil and oat residues. Experiment B, established in the 20 cm diameter cores and with maize cultivation, was used to assess plant growth and N uptake. An amount of 6.0 Mg ha-1 dry matter of oat residues was spread on the surface of the cores. A rate of 90 kg N ha-1 applied as ammonium sulphate in both experiments was split in pre-planting, planting and sidedress applications as follows: (a 00-00-00 (control, (b 90-00-00 (pre-planting application, 20 days before planting, (c 00-90-00 (planting application, (d 00-30-60 (split in a planting and a sidedress application 31 days after emergence, (e 00-00-00* (control, without oat residue and (f 90-00-00* (pre-planting application, without oat residue. The N concentration and N content in oat residues were not affected during decomposition by N fertilisation. Most of the fertiliser NH4+-N was converted into NO3--N within 20 days after application. A significant decrease in NO3--N contents in the 0-4 cm layer was observed in all treatments between 40 and 60 days after the oat residue placement on the soil surface, suggesting the occurrence of N immobilisation in this period. Considering that most of the inorganic N was converted into NO3- and that no immobilisation of the pre planting fertiliser N occurred at the

  8. Setting conservation targets for sandy beach ecosystems (United States)

    Harris, Linda; Nel, Ronel; Holness, Stephen; Sink, Kerry; Schoeman, David


    Representative and adequate reserve networks are key to conserving biodiversity. This begs the question, how much of which features need to be placed in protected areas? Setting specifically-derived conservation targets for most ecosystems is common practice; however, this has never been done for sandy beaches. The aims of this paper, therefore, are to propose a methodology for setting conservation targets for sandy beach ecosystems; and to pilot the proposed method using data describing biodiversity patterns and processes from microtidal beaches in South Africa. First, a classification scheme of valued features of beaches is constructed, including: biodiversity features; unique features; and important processes. Second, methodologies for setting targets for each feature under different data-availability scenarios are described. From this framework, targets are set for features characteristic of microtidal beaches in South Africa, as follows. 1) Targets for dune vegetation types were adopted from a previous assessment, and ranged 19-100%. 2) Targets for beach morphodynamic types (habitats) were set using species-area relationships (SARs). These SARs were derived from species richness data from 142 sampling events around the South African coast (extrapolated to total theoretical species richness estimates using previously-established species-accumulation curve relationships), plotted against the area of the beach (calculated from Google Earth imagery). The species-accumulation factor (z) was 0.22, suggesting a baseline habitat target of 27% is required to protect 75% of the species. This baseline target was modified by heuristic principles, based on habitat rarity and threat status, with final values ranging 27-40%. 3) Species targets were fixed at 20%, modified using heuristic principles based on endemism, threat status, and whether or not beaches play an important role in the species' life history, with targets ranging 20-100%. 4) Targets for processes and 5

  9. Balanço do nitrogênio da uréia (15N no sistema solo-planta na implantação da semeadura direta na cultura do milho Balance of nitrogen from urea (15N in the soil-plant system at the establishment of no-till in maize

    Directory of Open Access Journals (Sweden)

    Glauber José de Castro Gava


    and partitioning of the phytomass, in the accumulation of total nitrogen and nitrogen in the plant derived from the fertilizer, by using the 15N side-dressing fertilization at the establishment of no-till management. The experiment was carried out in a Nitosol at Água Sumida Farm located near Barra Bonita, State of São Paulo. The experiment was arranged in completely randomized block design, with 4 replicates. The following treatments were studied: conventional tillage system (one ploughing and two harrowings and no-tilllage, both fertilized with urea (15N applied at the rate of 100 kg ha-1 nitrogen. All treatments were subjected to sowing fertilization, by applying 25 kg ha-1 N as urea, 80 kg ha-1 P2O5 as simple superphosphate and 60 kg ha-1 K2O as potassium chloride. At the end of the phenological cycle, the following comparisons among the treatments were performed: crop yeld; nitrogen accumulation in the aerial and underground parts; use of nitrogen from urea (15N and residual nitrogen in the soil. The modifications of the soil caused by implantation of no-till neither restricted the availability of nitrogen to maize plants, nor the production of dry matter. The use efficiency of nitrogen fertilization of maize plants and the recovery of the soil nitrogen fertilizer were around 45% and 30%, respectively, for the urea-N side-dressing fertilization in both conventional and no-till systems. Nitrogen applied as side-dressing fertilization, and not recovered from urea (NNR averaged 25%, independently of the sowing system.

  10. Soil property control of biogeochemical processes beneath two subtropical stormwater infiltration basins (United States)

    O'Reilly, Andrew M.; Wanielista, Martin P.; Chang, Ni-Bin; Harris, Willie G.; Xuan, Zhemin


    Substantially different biogeochemical processes affecting nitrogen fate and transport were observed beneath two stormwater infiltration basins in north-central Florida. Differences are related to soil textural properties that deeply link hydroclimatic conditions with soil moisture variations in a humid, subtropical climate. During 2008, shallow groundwater beneath the basin with predominantly clayey soils (median, 41% silt+clay) exhibited decreases in dissolved oxygen from 3.8 to 0.1 mg L-1 and decreases in nitrate nitrogen (NO3-–N) from 2.7 mg L-1 to -1, followed by manganese and iron reduction, sulfate reduction, and methanogenesis. In contrast, beneath the basin with predominantly sandy soils (median, 2% silt+clay), aerobic conditions persisted from 2007 through 2009 (dissolved oxygen, 5.0–7.8 mg L-1), resulting in NO3-–N of 1.3 to 3.3 mg L-1 in shallow groundwater. Enrichment of d15N and d18O of NO3- combined with water chemistry data indicates denitrification beneath the clayey basin and relatively conservative NO3- transport beneath the sandy basin. Soil-extractable NO3-–N was significantly lower and the copper-containing nitrite reductase gene density was significantly higher beneath the clayey basin. Differences in moisture retention capacity between fine- and coarse-textured soils resulted in median volumetric gas-phase contents of 0.04 beneath the clayey basin and 0.19 beneath the sandy basin, inhibiting surface/subsurface oxygen exchange beneath the clayey basin. Results can inform development of soil amendments to maintain elevated moisture content in shallow soils of stormwater infiltration basins, which can be incorporated in improved best management practices to mitigate NO3- impacts.

  11. Rediscovering community--reflections after Hurricane Sandy. (United States)

    See, Sharon


    Hoboken, New Jersey, is a town of 50,000 residents located across the Hudson River from New York City. Most of Hoboken's infrastructure was compromised during Hurricane Sandy as a result of flooding and power outages that rendered many businesses inoperable, including all of the pharmacies in town. Despite a focus on emergency preparedness since Hurricane Katrina and 9/11, there were no contingencies in place to facilitate and assess the medication needs of the community in the event of a natural disaster. This essay describes how the author rediscovered the meaning of community, and through working with colleagues in other health care disciplines and non-health care volunteers, provided care to patients in suboptimal circumstances.

  12. Nitrate reduction in an unconfined sandy aquifer

    DEFF Research Database (Denmark)

    Postma, Diederik Jan; Boesen, Carsten; Kristiansen, Henning


    Nitrate distribution and reduction processes were investigated in an unconfined sandy aquifer of Quaternary age. Groundwater chemistry was studied in a series of eight multilevel samplers along a flow line, deriving water from both arable and forested land. Results show that plumes of nitrate...... processes of O2 and NO3- occur at rates that are fast compared to the rate of downward water transport. Nitrate-contaminated groundwater contains total contents of dissolved ions that are two to four times higher than in groundwater derived from the forested area. The persistence of the high content...... of total dissolved ions in the NO3- free anoxic zone indicates the downward migration of contaminants and that active nitrate reduction is taking place. Nitrate is apparently reduced to N2 because both nitrite and ammonia are absent or found at very low concentrations. Possible electron donors...


    Directory of Open Access Journals (Sweden)

    Ivan Knežević


    Full Text Available The academic textbook Stock Breeding in Tropical and Subtropical Conditions contains the following chapters: General part, Cattle and camels, Sheep and goats, Horses, donkeys, mules and hinnies, Index and Appendix with photographs of domestic animals in tropical and subtropical area. The textbook is written for students of the Faculty of Agriculture in Osijek and serves as a reading recommended within the module of the same title. Since 1997, when this module was introduced to curriculum as an elective course, students have showed great interest for gaining knowledge on cattle breeding in specific tropical and subtropical conditions. They prepared numerous seminary papers and final theses on the mentioned topic. Gaining of such knowledge contributes to openness and mobility of students to other European universities, which further promotes Bologna Process principles. The textbook covers all topics that are planned to be elaborated within the module. The handbook content is divided into two parts. The first part overviews numerous problems that producers of cattle in tropical and subtropical conditions are faced with. Some of those problems are also present in Croatia, especially in the warmer part of a year, becoming more obvious because of global climatic changes. Some breeds of cattle typical for tropical and subtropical areas are presented in the second part of the textbook within three chapters (Cattle and camels, Sheep and goats, Horses, donkeys, mules and hinnies. According to historical records, some of these animals, such as buffalos lived in our areas, particularly in Slavonia, while some other breeds live today across Europe and are treated as exotic animals.

  14. Human threats to sandy beaches: A meta-analysis of ghost crabs illustrates global anthropogenic impacts. (United States)

    Schlacher, Thomas A.; Lucrezi, Serena; Connolly, Rod M.; Peterson, Charles H.; Gilby, Ben L.; Maslo, Brooke; Olds, Andrew D.; Walker, Simon J.; Leon, Javier X.; Huijbers, Chantal M.; Weston, Michael A.; Turra, Alexander; Hyndes, Glenn A.; Holt, Rebecca A.; Schoeman, David S.


    Beach and coastal dune systems are increasingly subjected to a broad range of anthropogenic pressures that on many shorelines require significant conservation and mitigation interventions. But these interventions require reliable data on the severity and frequency of adverse ecological impacts. Such evidence is often obtained by measuring the response of 'indicator species'. Ghost crabs are the largest invertebrates inhabiting tropical and subtropical sandy shores and are frequently used to assess human impacts on ocean beaches. Here we present the first global meta-analysis of these impacts, and analyse the design properties and metrics of studies using ghost-crabs in their assessment. This was complemented by a gap analysis to identify thematic areas of anthropogenic pressures on sandy beach ecosystems that are under-represented in the published literature. Our meta-analysis demonstrates a broad geographic reach, encompassing studies on shores of the Pacific, Indian, and Atlantic Oceans, as well as the South China Sea. It also reveals what are, arguably, two major limitations: i) the near-universal use of proxies (i.e. burrow counts to estimate abundance) at the cost of directly measuring biological traits and bio-markers in the organism itself; and ii) descriptive or correlative study designs that rarely extend beyond a simple 'compare and contrast approach', and hence fail to identify the mechanistic cause(s) of observed contrasts. Evidence for a historically narrow range of assessed pressures (i.e., chiefly urbanisation, vehicles, beach nourishment, and recreation) is juxtaposed with rich opportunities for the broader integration of ghost crabs as a model taxon in studies of disturbance and impact assessments on ocean beaches. Tangible advances will most likely occur where ghost crabs provide foci for experiments that test specific hypotheses associated with effects of chemical, light and acoustic pollution, as well as the consequences of climate change (e

  15. Landscape Visual Quality and Meiofauna Biodiversity on Sandy Beaches. (United States)

    Felix, Gabriela; Marenzi, Rosemeri C; Polette, Marcos; Netto, Sérgio A


    Sandy beaches are central economic assets, attracting more recreational users than other coastal ecosystems. However, urbanization and landscape modification can compromise both the functional integrity and the attractiveness of beach ecosystems. Our study aimed at investigating the relationship between sandy beach artificialization and the landscape perception by the users, and between sandy beach visual attractiveness and biodiversity. We conducted visual and biodiversity assessments of urbanized and semiurbanized sandy beaches in Brazil and Uruguay. We specifically examined meiofauna as an indicator of biodiversity. We hypothesized that urbanization of sandy beaches results in a higher number of landscape detractors that negatively affect user evaluation, and that lower-rated beach units support lower levels of biodiversity. We found that urbanized beach units were rated lower than semiurbanized units, indicating that visual quality was sensitive to human interventions. Our expectations regarding the relationship between landscape perception and biodiversity were only partially met; only few structural and functional descriptors of meiofauna assemblages differed among classes of visual quality. However, lower-rated beach units exhibited signs of lower environmental quality, indicated by higher oligochaete densities and significant differences in meiofauna structure. We conclude that managing sandy beaches needs to advance beyond assessment of aesthetic parameters to also include the structure and function of beach ecosystems. Use of such supporting tools for managing sandy beaches is particularly important in view of sea level rise and increasing coastal development.

  16. Influência das coberturas vegetais antecessoras de aveia-preta e nabo forrageiro na época de controle de plantas daninhas em milho Influence of black oats and rape as cover crops on chemical weed control timing in no-till corn

    Directory of Open Access Journals (Sweden)

    M.A. Rizzardi


    Full Text Available Objetivou-se com este trabalho avaliar o efeito das coberturas de aveia-preta e nabo forrageiro na época de controle das plantas daninhas em milho. O arranjo experimental foi em blocos casualizados, com os tratamentos dispostos em parcelas subdivididas e com quatro repetições. Os tratamentos das parcelas principais constaram das coberturas vegetais e os das subparcelas, das épocas de controle químico de plantas daninhas, de acordo com os estádios de desenvolvimento da planta de milho (uma, duas, três, quatro, cinco e seis folhas, uma testemunha sem controle e uma com controle total das plantas daninhas. O controle químico destas foi em pós-emergência, com a associação dos herbicidas nicosulfuron + atrazine (Sanson 0,8 L ha-1 + Primóleo 0,3 L ha-1. Na presença de controle químico, a cobertura de aveia-preta mostrou ser mais eficiente sobre o rendimento de grãos de milho. A cobertura de nabo forrageiro exigiu maior critério quanto à época de controle das plantas daninhas, enquanto a aveia-preta permitiu maior flexibilidade. As melhores épocas de aplicação do herbicida ficaram entre os estádios de duas e três folhas do milho.The objective of this work was to assess the effect of rape and black oats as cover crops on chemical weed control timing in corn under no-till. The experiment was arranged in a complete block design, with the treatments in subplots and four replications. The main treatment plots were cover crops and the subplots the chemical weed control timings, according to corn growth stages (1, 2, 3, 4, 5 and 6 leaves. Two control plots, one with and the other without total weed control were added to the experiment. Weed chemical control was performed in postemergence with the association of the herbicides nicosulfuron + atrazine (Sanson 0.8 L ha-1 + Primóleo 0.3 L ha-1. When chemical control was applied, the cover crop black oat showed to be more efficient on corn grain yield. Rape was found to require more

  17. Análise espacial da ocorrência do índice de cone em área sob semeadura direta e sua relação com fatores do solo Spatial analysis of cone index under no-till and its relationship with soil physical attributes

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    José P. Molin


    Full Text Available O presente estudo teve o objetivo de analisar, em uma lavoura sob semeadura direta, a distribuição vertical e horizontal da resistência à penetração medida por valores georreferenciados do índice de cone (IC e a influência do teor de água do solo, permitindo a interpolação para análise de relações causa e efeito. Fatores importantes, como o teor de argila, silte, densidade, espaço poroso e teor de matéria orgânica do solo também foram mensurados. Utilizou-se de um penetrômetro hidráulico eletrônico, receptor de GPS, amostrador de solo e programas computacionais para o tratamento e obtenção dos resultados. A análise foi feita a partir dos mapas (não apresentados para a espacialização dos atributos e pela regressão entre os dados interpolados por meio da função que apresentou o coeficiente de determinação (R² mais elevado. Constatou-se a ocorrência de valores maiores para o IC nas profundidades compreendidas de 0,10 a 0,15 m, com menores valores em locais com maior teor de matéria orgânica, a qual coincidiu com maiores teores de argila e silte. O IC foi influenciado principalmente pelo teor de água, densidade e espaço poroso do solo.The objective of this study was to measure the vertical and horizontal distribution of georeferenced values of cone index (CI in a no-till field and the influence of soil water content. Data were interpolated to allow for cause and effect analysis. Other important factors as clay and silt content, bulk density, porous space and organic matter content were also measured. A penetrometer mounted on a tractor and equipped with a load cell was used together with GPS receiver, soil auger and computer programs to collect and analyze the data. Analysis was conducted based on maps of interpolated data after choosing the models with the highest determination coefficient (R² and regressions among them. High CI values were found at depths between 0.10 to 0.15 m. Lower values of CI were

  18. Use of solaria to predict weed density and floristic composition in no-till cropping systems Uso de solaria na predição da densidade de ervas daninhas e da composição florística no sistema de semeadura direta

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    Pablo Antonio Calviño


    Full Text Available The objective of this work was to evaluate the efficiency of a new method, developed for predicting density and floristic composition of weed communities in field crops. Based on the use of solaria (100 mm transparent plastic tarps lying on the soil to stimulate weed seedlings emergence, the method was tested in Tandil, Argentina, from 1998 to 2001. The system involved corn and sunflower in commercial no-till system. Major weeds in the experiments included Digitaria sanguinalis, Setaria verticillata and S. viridis, which accounted for 98% of the weed community in the three years of experiments since 1998. Large numbers of Tagetes minuta, Chenopodium album and Ammi majus were present in 2001. Comparison of weed communities under solaria with communities in field crops indicated that the method is useful for predicting the presence and density of some major weed species, at both high and low densities, of individuals in areas of 10 ha using only five solaria. Low density of weed species makes the method particularly useful to help deciding the time for herbicide applications to avoid soil contamination.O objetivo deste trabalho foi avaliar a eficiência de novo método, desenvolvido para predizer a densidade e a composição florística das comunidades de plantas daninhas. O método é baseado no uso de solaria (plástico transparente de 100 mm sobre o solo, a fim de estimular o aparecimento de ervas daninhas, e foi testado em Tandil, Argentina, de 1998 a 2001. O sistema envolve milho e girassol, em cultivos comerciais em semeadura direta. As principais espécies experimentadas foram Digitaria sanguinalis, Setaria verticillata e S. viridis, que responderam por 98% da comunidade nos três anos de experiência. Números altos de Tagetes minuta, Chenopodium album e Ammi majus estavam presentes em 2001. A comparação de comunidades de ervas daninhas sob solaria com comunidades fora de solaria indicou que o método é útil para predizer a presença e

  19. Short Communication Energy and ash contents of sandy beach ...

    African Journals Online (AJOL)

    Currey 1970). Thus in large crustaceans. Table 4 Percentage ash contents of sandy beach species. Species. Tylos gralluialws. Pofttogeioides latipes. Eurydice iongicornis. Excirolana Nllalensis. Niambia. sp. TalochLrtia. capensis. Pseudharpi1lia ...

  20. Studies on Thiobacilli spp. isolated from sandy beaches of Kerala

    Digital Repository Service at National Institute of Oceanography (India)

    Gore, P.S.; Raveendran, O.; Unnithan, R.V.

    Occurrence, isolation and oxidative activity of Thiobacilli spp. from some sandy beaches of Kerala are reported. These organisms were encountered in polluted beaches and were dominant during monsoon in all the beaches...

  1. Shoreface response and recovery to Hurricane Sandy: Fire Island, NY (United States)

    Nelson, Timothy R.; Hapke, Cheryl J.; Wang, Ping; Rosati, Julie D.; Cheng, Jun


    The shoreface of Fire Island was extensively modified by Hurricane Sandy and subsequent storms in the following winter months. The changes were evaluated using various morphometrics of the shoreface from four bathymetric surveys, one prior to Hurricane Sandy, and three over the course of twenty months following Sandy. The datasets show that the nearshore bar system moved offshore to deeper water depths following Hurricane Sandy with volume lost from the subaerial beach and surfzone. Following the offshore shift, the nearshore bar system increased in size, the trough deepened, and there has been gradual landward movement of the nearshore bar. The steepening of the upper shoreface, landward translation of the profile, and loss of sediment is indicative of barrier island transgression.

  2. 2014 USGS CMGP Lidar: Sandy Restoration (Delaware and Maryland) (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Geographic Extent: SANDY_Restoration_DE_MD_QL2 Area of Interest covers approximately 3.096 square miles. Lot #5 contains the full project area Dataset Description:...

  3. On the Impact Angle of Hurricane Sandy's New Jersey Landfall (United States)

    Hall, Timothy M.; Sobel, Adam H.


    Hurricane Sandy's track crossed the New Jersey coastline at an angle closer to perpendicular than any previous hurricane in the historic record, one of the factors contributing to recordsetting peak-water levels in parts of New Jersey and New York. To estimate the occurrence rate of Sandy-like tracks, we use a stochastic model built on historical hurricane data from the entire North Atlantic to generate a large sample of synthetic hurricanes. From this synthetic set we calculate that under long-term average climate conditions, a hurricane of Sandy's intensity or greater (category 1+) makes NJ landfall at an angle at least as close to perpendicular as Sandy's at an average annual rate of 0.0014 yr-1 (95% confidence range 0.0007 to 0.0023); i.e., a return period of 714 years (95% confidence range 435 to 1429).

  4. Macrofauna and meiofauna of two sandy beaches at Mombasa, Kenya

    Digital Repository Service at National Institute of Oceanography (India)

    Ansari, Z.A.; Ingole, B.S.; Parulekar, A.H.

    Macrofauna and meiofauna of 2 sandy beaches having medium and fine sand particles, respectively, were investigated, quantitatively Macrofauna density was highest around high water mark and progressively decreased towards low water mark Meiofauna...

  5. Hurricane Sandy: Rapid Response Imagery of the Surrounding Regions (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The imagery posted on this site is of Hurricane Sandy. The aerial photography missions were conducted by the NOAA Remote Sensing Division. The images were acquired...

  6. 2008 USDA Forest Service Lidar: Sandy River Study Area (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Watershed Sciences, Inc. collected Light Detection and Ranging (LiDAR) data for the Sandy River study area in collaboration with the USDA Forest Service. The areas...

  7. 2014 USGS CMGP Lidar: Post Sandy (Long Island, NY) (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — TASK NAME: Long Island New York Sandy LIDAR lidar Data Acquisition and Processing Production Task USGS Contract No. G10PC00057 Task Order No. G14PD00296 Woolpert...

  8. Complex, Dynamic Combination of Physical, Chemical and Nutritional Variables Controls Spatio-Temporal Variation of Sandy Beach Community Structure (United States)

    Ortega Cisneros, Kelly; Smit, Albertus J.; Laudien, Jürgen; Schoeman, David S.


    Sandy beach ecological theory states that physical features of the beach control macrobenthic community structure on all but the most dissipative beaches. However, few studies have simultaneously evaluated the relative importance of physical, chemical and biological factors as potential explanatory variables for meso-scale spatio-temporal patterns of intertidal community structure in these systems. Here, we investigate macroinfaunal community structure of a micro-tidal sandy beach that is located on an oligotrophic subtropical coast and is influenced by seasonal estuarine input. We repeatedly sampled biological and environmental variables at a series of beach transects arranged at increasing distances from the estuary mouth. Sampling took place over a period of five months, corresponding with the transition between the dry and wet season. This allowed assessment of biological-physical relationships across chemical and nutritional gradients associated with a range of estuarine inputs. Physical, chemical, and biological response variables, as well as measures of community structure, showed significant spatio-temporal patterns. In general, bivariate relationships between biological and environmental variables were rare and weak. However, multivariate correlation approaches identified a variety of environmental variables (i.e., sampling session, the C∶N ratio of particulate organic matter, dissolved inorganic nutrient concentrations, various size fractions of photopigment concentrations, salinity and, to a lesser extent, beach width and sediment kurtosis) that either alone or combined provided significant explanatory power for spatio-temporal patterns of macroinfaunal community structure. Overall, these results showed that the macrobenthic community on Mtunzini Beach was not structured primarily by physical factors, but instead by a complex and dynamic blend of nutritional, chemical and physical drivers. This emphasises the need to recognise ocean-exposed sandy

  9. CO2 and N2O emissions from an Andisol in Chile under a no-till system using non-fixed closed chambers Emisiones de CO2 y N2O desde un Andisol de Chile bajo sistema de cero labranza usando cámaras cerradas no-fijas

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    Cristina Muñoz


    Full Text Available Chile has different types of soil and climate conditions that favor a wide range of agricultural activities that can generate potential atmospheric contamination like greenhouse gases (GHG. Nevertheless, the contribution of agricultural soils to atmospheric emissions has yet to be measured in Chile. The aim of this study was to assess seasonal variability of CO2 and N2O effluxes in situ from a volcanic ash-derived soil under different agronomic management practices. Gas samples were obtained from headspaces of non-fixed closed chambers in an annual crop rotation under a no-till system in an Andisol in southern Chile (36° S. Two N-sources (NH4+ and NO3- and ammonium fertilization plus two lime doses (0.5 and 1 Mg ha-1 were considered for soil treatments Effluxes of CO2 and N2O were determined periodically for 1 yr, and soil variables, such as temperature, water, and mineral N content, were recorded. Results showed that CO2 effluxes respond to a seasonal pattern. No effect was evidenced when considering crop management practices with a maximum of 53.2 ± 8.5 kg CO2-C ha-1 d-1 in the wet fall period and a minimum of 9.7 ± 2.1 kg CO2-C ha-1 d-1 for summer, fall dry period, and winter. N2O efflux was highly variable throughout the year and showed no influence of treatments or season variability with a mean of 0.95 kg N2O-N ha-1 yr-1. Soil mineral N variations are not related to GHG effluxes as a single variable. Results indicate that an Andisol under a no-till system in southern Chile has a low N2O emission potential, and higher CO2 emissions are mainly produced in wet seasons (wet fall and/or spring.Chile tiene diferentes tipos de suelo y condiciones climáticas que favorecen un amplio rango de actividades agrícolas, las cuales pueden generar contaminación atmosférica potencial como los gases de efecto invernadero (GHG. Sin embargo, mediciones de la contribución de los suelos agrícolas en las emisiones atmosféricas de estos gases no ha sido

  10. Gravitational Motions in a Large Subtropical Reservoir (United States)

    Marti, C. L.; Imberger, J.


    Subtropical lakes and reservoirs are characterized by a definite, but moderate vertical thermal stratification, so that vertical mixing is the result of a balance between the surface buoyancy flux and wind stirring and horizontal exchanges are the result of a series of gravitational motions: differential mixing, cooling, heating, and absorption. Here we report on two field experiments carried out in Lake Argyle, Australia's second largest artificial lake by volume, in May 2012 and November 2013 that illustrate the delicate balance that exists in subtropical lakes between buoyancy and inertia and how this balance interacts with the resident biology. The field experiments were conducted using a state-of-the-art real-time field technology that allows instant comparison of field data and 3D numerical modelling results of all physical variables at micro and fine scales and phytoplankton concentration at the group level. The results demonstrate that subtropical lakes present special opportunities and challenges for mitigation of water quality problems in face of global warming.

  11. Sandy beaches: state of the art of nematode ecology

    Directory of Open Access Journals (Sweden)


    Full Text Available ABSTRACT In this review, we summarize existing knowledge of the ecology of sandy-beach nematodes, in relation to spatial distribution, food webs, pollution and climate change. We attempt to discuss spatial scale patterns (macro-, meso- and microscale according to their degree of importance in structuring sandy-beach nematode assemblages. This review will provide a substantial background on current knowledge of sandy-beach nematodes, and can be used as a starting point to delineate further investigations in this field. Over decades, sandy beaches have been the scene of studies focusing on community and population ecology, both related to morphodynamic models. The combination of physical factors (e.g. grain size, tidal exposure and biological interactions (e.g. trophic relationships is responsible for the spatial distribution of nematodes. In other words, the physical factors are more important in structuring nematodes communities over large scale of distribution while biological interactions are largely important in finer-scale distributions. It has been accepted that biological interactions are assumed to be of minor importance because physical factors overshadow the biological interactions in sandy beach sediments; however, the most recent results from in-situ and ex-situ experimental investigations on behavior and biological factors on a microscale have shown promise for understanding the mechanisms underlying larger-scale patterns and processes. Besides nematodes are very promising organisms used to understand the effects of pollution and climate changes although these subjects are less studied in sandy beaches than distribution patterns.

  12. EAARL-B Coastal Topography--Eastern New Jersey, Hurricane Sandy, 2012: First Surface, Pre-Sandy (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — ASCII xyz and binary point-cloud data, as well as a digital elevation model (DEM) of a portion of the New Jersey coastline, pre- and post-Hurricane Sandy (October...

  13. Respirable dust and quartz exposure from three South African farms with sandy, sandy loam, and clay soils. (United States)

    Swanepoel, Andrew J; Kromhout, Hans; Jinnah, Zubair A; Portengen, Lützen; Renton, Kevin; Gardiner, Kerry; Rees, David


    To quantify personal time-weighted average respirable dust and quartz exposure on a sandy, a sandy loam, and a clay soil farm in the Free State and North West provinces of South Africa and to ascertain whether soil type is a determinant of exposure to respirable quartz. Three farms, located in the Free State and North West provinces of South Africa, had their soil type confirmed as sandy, sandy loam, and clay; and, from these, a total of 298 respirable dust and respirable quartz measurements were collected between July 2006-November 2009 during periods of major farming operations. Values below the limit of detection (LOD) (22 μg · m(-3)) were estimated using multiple 'imputation'. Non-parametric tests were used to compare quartz exposure from the three different soil types. Exposure to respirable quartz occurred on all three farms with the highest individual concentration measured on the sandy soil farm (626 μg · m(-3)). Fifty-seven, 59, and 81% of the measurements on the sandy soil, sandy loam soil, and clay soil farm, respectively, exceeded the American Conference of Governmental Industrial Hygienists (ACGIH) threshold limit value (TLV) of 25 μg · m(-3). Twelve and 13% of respirable quartz concentrations exceeded 100 μg · m(-3) on the sandy soil and sandy loam soil farms, respectively, but none exceeded this level on the clay soil farm. The proportions of measurements >100 μg · m(-3) were not significantly different between the sandy and sandy loam soil farms ('prop.test'; P = 0.65), but both were significantly larger than for the clay soil farm ('prop.test'; P = 0.0001). The percentage of quartz in respirable dust was determined for all three farms using measurements > the limit of detection. Percentages ranged from 0.5 to 94.4% with no significant difference in the median quartz percentages across the three farms (Kruskal-Wallis test; P = 0.91). This study demonstrates that there is significant potential for over-exposure to respirable quartz in

  14. Brazilian sandy beach macrofauna production: a review

    Directory of Open Access Journals (Sweden)

    Marcelo Petracco


    Full Text Available The state of the art of the studies on the production of Brazilian sandy beach macrofauna was analyzed on the basis of the data available in the literature. For this purpose, the representativeness of the production dataset was examined by latitudinal distribution, degree of exposure and morphodynamic state of beaches, taxonomic groups, and methods employed. A descriptive analysis was, further, made to investigate the trends in production of the more representative taxonomic groups and species of sandy beach macrofauna. A total of 69 macrofauna annual production estimates were obtained for 38 populations from 25 studies carried out between 22º56'S and 32º20'S. Production estimates were restricted to populations on beaches located on the southern and southeastern Brazilian coast. Most of the populations in the dataset inhabit exposed dissipative sandy beaches and are mainly represented by mollusks and crustaceans, with a smaller number of polychaetes. The trends in production among taxonomic groups follow a similar pattern to that observed on beaches throughout the world, with high values for bivalves and decapods. The high turnover rate (P/B ratio of the latter was due to the presence of several populations of the mole crab Emerita brasiliensis, which can attain high values of productivity, in the dataset. Most of the studies focus on the comparison of production and, especially, of P/B ratio according to life history traits in populations of the same species/taxonomic group. Despite the importance of life history-production studies, other approaches, such as the effect of man-induce disturbances on the macrofauna, should be undertaken in these threatened environments.O estado da arte dos estudos de produção da macrofauna de praias arenosas brasileiras foi analisado a partir de informações disponíveis na literatura. Para essa finalidade, a representatividade dos dados de produção foi examinada de acordo com a distribuição latitudinal

  15. Aplicação de gesso agrícola e especiação iônica da solução de um Latossolo sob sistema plantio direto Gypsum application and ionic speciation of the solution from an Oxisol under no-till system

    Directory of Open Access Journals (Sweden)

    Fernando César Bachiega Zambrosi


    Full Text Available O baixo teor de Ca e a toxicidade por Al são importantes limitações à produtividade das culturas em solos ácidos brasileiros. É possível aumentar o teor de Ca e reduzir a toxicidade por Al por meio da aplicação de gesso agrícola. No entanto, é importante melhor compreensão dos efeitos do gesso na especiação iônica da solução do solo. Avaliou-se a especiação iônica da solução do solo (extrato aquoso 1:1 de amostras de um Latossolo Vermelho distrófico textura argilosa, sob sistema plantio direto, cinco anos após a aplicação superficial de 3, 6 e 9t ha-1 de gesso agrícola. A especiação foi realizada com auxílio do programa computacional Visual Minteq em amostras coletadas nas profundidades de 0-0,05; 0,05-0,1; 0,1-0,2 e 0,2-0,4m. Para o Al, as principais espécies químicas foram os complexos com carbono orgânico dissolvido (Al-COD e com F (Al-F, enquanto o par iônico AlSO4+ ocorreu em pequena proporção. O COD foi o principal ligante para Mg e Ca, mas em muito maior magnitude para este último, refletindo importante participação dos ânions orgânicos na dinâmica desses nutrientes. Em relação ao sulfato, apesar da formação dos pares iônicos com Ca, Mg e Al (CaSO4(0, MgSO4(0 e AlSO4+, houve a predominância da forma livre S-SO4-2, enquanto o fosfato apresentou forte interação com o Al em solução, formando a espécie química Al-HxPO4x.Low Ca content and Al toxicity are important limitations for yield crops in Brazilian acids soils. Gypsum application may increase Ca contents and decrease Al toxicity. However, a better knowledge of the effects of gypsum on the ionic speciation of soil solution is very important. The ionic speciation of the soil solution (water extract 1:1 was evaluated in samples from a dystrophic clayey Rhodic Hapludox under no-till system, 5 years after surface application of gypsum (3; 6 and 9t ha-1. The ionic speciation was performed by using the Visual Minteq program in samples

  16. Application times, sources and doses of nitrogen on wheat cultivars under no till in the Cerrado region Épocas de aplicação, fontes e doses de nitrogênio em cultivares de trigo sob plantio direto na região do cerrado

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    Marcelo Carvalho Minhoto Teixeira Filho


    Full Text Available Proper management of nitrogen fertilization and using cultivars with high productive potential are essential to obtain high wheat yield. Thus, the objective of the present study was to assess the effects of different N doses and sources, one with a nitrification inhibitor, applied at sowing or as side dressing, on the production components and yield of two wheat cultivars irrigated, under no till, cultivated in a region of low altitude Cerrado (Selvíria - MS. A randomized block design was used in a 5x3x2x2 factorial arrangement, that is, five nitrogen doses (0, 50, 100, 150 and 200kg ha-1, three nitrogen sources (ammonium sulfonitrate with nitrification inhibitor (Entec®, ammonium sulfate and urea and two nitrogen application times (at sowing or side dressing on two wheat cultivars ('E 22' and 'E 42' with three replications. There was no difference for grain yield between the wheat cultivars and among the nitrogen sources. The application of nitrogen totally at sowing is feasible as well as the traditional application at sowing and side dressing. The nitrogen doses increased the leaf N content of the 'E 22' cultivar, resulting in a reduction in the hectolitric mass of the 'E 42' cultivar and increased grain yield of the 'E 22' and 'E 42' wheat yield cultivars, respectively, up to doses of 126 and 122kg ha-1 N, regardless of the application time and the nitrogen source.O manejo adequado da adubação nitrogenada e a utilização de cultivares de alto potencial produtivo são essenciais para obtenção de altas produtividades de trigo. Sendo assim, o objetivo deste trabalho foi avaliar os efeitos de diferentes doses e fontes de N, sendo uma com inibidor de nitrificação, aplicadas no sulco de semeadura ou em cobertura, nos componentes de produção e na produtividade de duas cultivares de trigo irrigado, sob plantio direto, cultivado numa região de cerrado de baixa altitude (Selvíria - MS. O delineamento estatístico foi o de blocos ao acaso

  17. Semeadura direta de forrageiras de estação fria em campo natural submetido à aplicação de herbicidas: II. Composição botânica No-till seeding of cold season forage on native pasture under herbicides application: II. Botanical composition

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    Enrique Pérez Gomar


    Full Text Available A semeadura direta de espécies forrageiras de estação fria permite reduzir a marcada estacionalidade da sua produção em campos naturais. Durante quatro anos, conduziu-se um experimento de aplicação de herbicidas sobre campo nativo, em um solo Argissolo Vermelho-Amarelo, de textura arenosa do norte do Uruguai visando introduzir forrageiras de estação fria e estudar o impacto dos herbicidas na composição botânica de espécies estivais. Foram testadas doses de herbicidas (glifosate 1L ha-1, glifosate 4L ha-1, paraquat 3L ha-1 e testemunha, como tratamento principal, aplicadas no ano 1994, em um delineamento blocos ao acaso. A repetição ou não das mesmas doses no ano 1995 constituiu a subparcela e a aplicação ou não das mesmas doses no ano de 1996 constituiu a sub-subparcela. No levantamento de espécies da vegetação existentes no outono de 1998, observou-se que o maior distúrbio sobre a composição botânica do campo nativo foi provocado com a aplicação continuada da dose de 4L ha-1 de glifosate, onde foram identificadas seis espécies. No levantamento de espécies existentes no tratamento testemunha, no outono, foram identificadas onze espécies, sendo que as espécies Andropogon lateralis, Paspalum notatum, Conyza bonariensis, Eryngium horridum, Desmodium incanum, Cyperus sp. e Digitaria sp. constituiram 90% da composição botânica. Com a aplicação de herbicida, ocorreu uma substituição de espécies perenes por anuais.No-till seeding of winter species may reduce seasonal fluctuations of forage production of natural grasslands. An experiment of herbicide application on native grasses was conducted for four years, on a fine-loamy, mixed Mollic Hapludalf in northern of Uruguay to introduce winter forage and study the impact of herbicide on botanical composition of grass field. The experimental design was split-splitplot with three randomized blocks, with types and dosis of herbicides (gliphosate 1L ha-1, gliphosate 4L

  18. Produção de fitomassa por plantas de cobertura e mineralização de seus resíduos em plantio direto Cover crops biomass production and its residues mineralization in a Brazilian no-till Oxisol

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    Jose Luiz Rodrigues Torres


    Full Text Available O objetivo deste trabalho foi avaliar a produção de fitomassa seca, a taxa de decomposição das palhadas e as quantidades de macronutrientes (N, P, Ca, Mg e S liberadas dos resíduos vegetais de sete plantas de cobertura de solo, em condições de Cerrado, por dois anos. As plantas de cobertura avaliadas foram: milheto (Pennisetum americanum sin. typhoides, braquiária (Brachiaria brizantha cv. Marandu, sorgo forrageiro [Sorghum bicolor (L. Moench], guandu [Cajanus cajan (L. Millsp.], crotalária juncea (Crotalaria juncea L., aveia-preta (Avena strigosa Schreb e a vegetação espontânea de uma parcela em pousio. Utilizou-se o delineamento em blocos ao acaso, com quatro repetições, implantado em um Latossolo Vermelho, textura média. Avaliou-se a produção de fitomassa seca 110 dias após a semeadura. A taxa de decomposição foi quantificada por meio de sacolas de náilon contendo os resíduos culturais, coletadas em intervalos regulares. Observou-se que milheto e crotalária são as coberturas gramínea e leguminosa com maior produção de fitomassa seca e acúmulo de N, nos dois períodos avaliados. A maior taxa de decomposição das plantas de cobertura e de liberação de nutrientes ocorre aos 42 dias após a dessecação. Os maiores tempos de meia-vida foram observados no período de menor precipitação pluvial.The objective of this work was to evaluate dry biomass production, decomposition rate and macronutrients release (N, P, Ca, Mg and S of cover crops cultural residues, in a no-till savanna soil. The cover crops tested were: pearl millet (Pennisetum americanum sin. typhoides, brachiaria grass (Brachiaria brizantha cv. Marandu, sorghum [Sorghum bicolor (L. Moench], pigeon pea [Cajanus cajan (L. Millsp.], sunn hemp (Crotalaria juncea L. and black oat (Avena strigosa Schreb, compared to a fallow plot (control. The experiment was carried out in an Oxisol, medium texture. A randomized block design, in a split-plot array in time

  19. Sandy River Delta Habitat Restoration Project, Annual Report 2001.

    Energy Technology Data Exchange (ETDEWEB)

    Kelly, Virginia; Dobson, Robin L.


    The Sandy River Delta is located at the confluence of the Sandy and Columbia Rivers, just east of Troutdale, Oregon. It comprises about 1,400 land acres north of Interstate 84, managed by the USDA Forest Service, and associated river banks managed by the Oregon Division of State Lands. Three islands, Gary, Flag and Catham, managed by Metro Greenspaces and the State of Oregon lie to the east, the Columbia River lies to the north and east, and the urbanized Portland metropolitan area lies to the west across the Sandy River. Sandy River Delta was historically a wooded, riparian wetland with components of ponds, sloughs, bottomland woodland, oak woodland, prairie, and low and high elevation floodplain. It has been greatly altered by past agricultural practices and the Columbia River hydropower system. Restoration of historic landscape components is a primary goal for this land. The Forest Service is currently focusing on restoration of riparian forest and wetlands. Restoration of open upland areas (meadow/prairie) would follow substantial completion of the riparian and wetland restoration. The Sandy River Delta is a former pasture infested with reed canary grass, blackberry and thistle. The limited over story is native riparian species such as cottonwood and ash. The shrub and herbaceous layers are almost entirely non-native, invasive species. Native species have a difficult time naturally regenerating in the thick, competing reed canary grass, Himalayan blackberry and thistle. A system of drainage ditches installed by past owners drains water from historic wetlands. The original channel of the Sandy River was diked in the 1930's, and the river diverted into the ''Little Sandy River''. The original Sandy River channel has subsequently filled in and largely become a slough. The FS acquired approximately 1,400 acres Sandy River Delta (SRD) in 1991 from Reynolds Aluminum (via the Trust for Public Lands). The Delta had been grazed for many years

  20. EAARL Coastal Topography - Sandy Hook 2007 (United States)

    Nayegandhi, Amar; Brock, John C.; Wright, C. Wayne; Stevens, Sara; Yates, Xan; Bonisteel, Jamie M.


    These remotely sensed, geographically referenced elevation measurements of Lidar-derived topography were produced as a collaborative effort between the U.S. Geological Survey (USGS), Florida Integrated Science Center (FISC), St. Petersburg, FL; the National Park Service (NPS), Northeast Coastal and Barrier Network, Kingston, RI; and the National Aeronautics and Space Administration (NASA), Wallops Flight Facility, VA. This project provides highly detailed and accurate datasets of Gateway National Recreation Area's Sandy Hook Unit in New Jersey, acquired on May 16, 2007. The datasets are made available for use as a management tool to research scientists and natural resource managers. An innovative airborne Lidar instrument originally developed at the NASA Wallops Flight Facility, and known as the Experimental Advanced Airborne Research Lidar (EAARL) was used during data acquisition. The EAARL system is a raster-scanning, waveform-resolving, green-wavelength (532-nanometer) Lidar designed to map near-shore bathymetry, topography, and vegetation structure simultaneously. The EAARL sensor suite includes the raster-scanning, water-penetrating full-waveform adaptive Lidar, a down-looking red-green-blue (RGB) digital camera, a high-resolution multi-spectral color infrared (CIR) camera, two precision dual-frequency kinematic carrier-phase GPS receivers and an integrated miniature digital inertial measurement unit, which provide for submeter georeferencing of each laser sample. The nominal EAARL platform is a twin-engine Cessna 310 aircraft, but the instrument may be deployed on a range of light aircraft. A single pilot, a Lidar operator, and a data analyst constitute the crew for most survey operations. This sensor has the potential to make significant contributions in measuring sub-aerial and submarine coastal topography within cross-environmental surveys. Elevation measurements were collected over the survey area using the EAARL system, and the resulting data were then

  1. Microstructure characteristics of cement-stabilized sandy soil using nanosilica

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    Asskar Janalizadeh Choobbasti


    Full Text Available An experimental program was conducted to explore the impact of nanosilica on the microstructure and mechanical characteristics of cemented sandy soil. Cement agent included Portland cement type II. Cement content was 6% by weight of the sandy soil. Nanosilica was added in percentages of 0%, 4%, 8% and 12% by weight of cement. Cylindrical samples were prepared with relative density of 80% and optimum water content and cured for 7 d, 28 d and 90 d. Microstructure characteristics of cement-nanosilica-sand mixtures after 90 d of curing have been explored using atomic force microscopy (AFM, scanning electron microscopy (SEM and X-ray diffraction (XRD tests. Effects of curing time on microstructure properties of cemented sandy soil samples with 0% and 8% nanosilica have been investigated using SEM test. Unconfined compression test (for all curing times and compaction test were also performed. The SEM and AFM tests results showed that nanosilica contributes to enhancement of cemented sandy soil through yielding denser, more uniform structure. The XRD test demonstrated that the inclusion of nanosilica in the cemented soil increases the intensity of the calcium silicate hydrate (CSH peak and decreases the intensity of the calcium hydroxide (CH peak. The results showed that adding optimum percentages of nanosilica to cement-stabilized sandy soil enhances its mechanical and microstructure properties.

  2. Hurricane Sandy, Disaster Preparedness, and the Recovery Model. (United States)

    Pizzi, Michael A


    Hurricane Sandy was the second largest and costliest hurricane in U.S. history to affect multiple states and communities. This article describes the lived experiences of 24 occupational therapy students who lived through Hurricane Sandy using the Recovery Model to frame the research. Occupational therapy student narratives were collected and analyzed using qualitative methods and framed by the Recovery Model. Directed content and thematic analysis was performed using the 10 components of the Recovery Model. The 10 components of the Recovery Model were experienced by or had an impact on the occupational therapy students as they coped and recovered in the aftermath of the natural disaster. This study provides insight into the lived experiences and recovery perspectives of occupational therapy students who experienced Hurricane Sandy. Further research is indicated in applying the Recovery Model to people who survive disasters. Copyright © 2015 by the American Occupational Therapy Association, Inc.

  3. Mercury in tropical and subtropical coastal environments (United States)

    Costa, Monica F.; Landing, William M.; Kehrig, Helena A.; Barletta, Mário; Holmes, Christopher D.; Barrocas, Paulo R. G.; Evers, David C.; Buck, David G.; Vasconcellos, Ana Claudia; Hacon, Sandra S.; Moreira, Josino C.; Malm, Olaf


    Anthropogenic activities influence the biogeochemical cycles of mercury, both qualitatively and quantitatively, on a global scale from sources to sinks. Anthropogenic processes that alter the temporal and spatial patterns of sources and cycling processes are changing the impacts of mercury contamination on aquatic biota and humans. Human exposure to mercury is dominated by the consumption of fish and products from aquaculture operations. The risk to society and to ecosystems from mercury contamination is growing, and it is important to monitor these expanding risks. However, the extent and manner to which anthropogenic activities will alter mercury sources and biogeochemical cycling in tropical and sub-tropical coastal environments is poorly understood. Factors as (1) lack of reliable local/regional data; (2) rapidly changing environmental conditions; (3) governmental priorities and; (4) technical actions from supra-national institutions, are some of the obstacles to overcome in mercury cycling research and policy formulation. In the tropics and sub-tropics, research on mercury in the environment is moving from an exploratory “inventory” phase towards more process-oriented studies. Addressing biodiversity conservation and human health issues related to mercury contamination of river basins and tropical coastal environments are an integral part of paragraph 221 paragraph of the United Nations document “The Future We Want” issued in Rio de Janeiro in June 2012. PMID:22901765

  4. Family Structures, Relationships, and Housing Recovery Decisions after Hurricane Sandy

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    Ali Nejat


    Full Text Available Understanding of the recovery phase of a disaster cycle is still in its infancy. Recent major disasters such as Hurricane Sandy have revealed the inability of existing policies and planning to promptly restore infrastructure, residential properties, and commercial activities in affected communities. In this setting, a thorough grasp of housing recovery decisions can lead to effective post-disaster planning by policyholders and public officials. The objective of this research is to integrate vignette and survey design to study how family bonds affected rebuilding/relocating decisions after Hurricane Sandy. Multinomial logistic regression was used to investigate respondents’ family structures before Sandy and explore whether their relationships with family members changed after Sandy. The study also explores the effect of the aforementioned relationship and its changes on households’ plans to either rebuild/repair their homes or relocate. These results were compared to another multinomial logistic regression which was applied to examine the impact of familial bonds on respondents’ suggestions to a vignette family concerning rebuilding and relocating after a hurricane similar to Sandy. Results indicate that respondents who lived with family members before Sandy were less likely to plan for relocating than those who lived alone. A more detailed examination shows that this effect was driven by those who improved their relationships with family members; those who did not improve their family relationships were not significantly different from those who lived alone, when it came to rebuilding/relocation planning. Those who improved their relationships with family members were also less likely to suggest that the vignette family relocate. This study supports the general hypothesis that family bonds reduce the desire to relocate, and provides empirical evidence that family mechanisms are important for the rebuilding/relocating decision

  5. Impact of polar ozone depletion on subtropical precipitation. (United States)

    Kang, S M; Polvani, L M; Fyfe, J C; Sigmond, M


    Over the past half-century, the ozone hole has caused a poleward shift of the extratropical westerly jet in the Southern Hemisphere. Here, we argue that these extratropical circulation changes, resulting from ozone depletion, have substantially contributed to subtropical precipitation changes. Specifically, we show that precipitation in the southern subtropics in austral summer increases significantly when climate models are integrated with reduced polar ozone concentrations. Furthermore, the observed patterns of subtropical precipitation change, from 1979 to 2000, are very similar to those in our model integrations, where ozone depletion alone is prescribed. In both climate models and observations, the subtropical moistening is linked to a poleward shift of the extratropical westerly jet. Our results highlight the importance of polar regions for the subtropical hydrological cycle.

  6. Porosidade e retenção de água em um argissolo sob manejos convencional e direto submetido a compressões unidimensionais Porosity and water retention in an acrisol under conventional and no-till systems under uniaxial compression

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    Edson Campanhola Bortoluzzi


    preparo no potencial de água de -100 kPa. Pode-se inferir que o solo sob sistema de preparo convencional foi mais sensível ao estresse mecânico que aquele sob plantio direto, evidenciando a diminuição da porosidade e consequentemente da proporção de ar.To date, little is known about the dynamics of water and air in porous spaces of soils exposed to mechanical stresses, mainly when the pressure is located on the pre-consolidation line. This study aimed to quantify the changes in the porous spaces of an Acrisol under two tillage systems, submitted to increasing one-dimensional compression, emphasizing the bulk density and water retention at two water potential levels. Undisturbed soil samples were collected under conventional tillage (CT and no-till (NT, with three replications, from the Ap surface horizon (0-0.075 m of an Red-Yellow Dystrophic Acrisol at the Universidade Federal de Santa Maria in Rio Grande do Sul State. The sample water content was standardized at -32 kPa in a Richards membrane-plate extractor and the samples were submitted to one-dimensional pressures of 0, 50, 100, and 200 kPa in an open-drained oedometric cell. After the trial, clods were pushed by hand and were submitted in four replications to two water potential levels (-1.600 and -100 kPa in a Richards membrane (cell. Sample volumes as well as gravimetric water contents were determined by weighing in kerosene after oven-drying at 105 °C. ANOVA was performed as well as regression analysis, whenever necessary. The response of soil bulk density to the increasing pressure was a linear function for SPD and a square function for SPD. In both management systems the water content was exponentially related with the stress levels. Variation in water retention can be explained by 85 % by the one-dimensional compression, which was positive for CT and negative for NT. At a water potential of -100 kPa the changes in bulk density and gravimetric water content were relevant in both management systems. It

  7. Alterações em atributos do solo decorrentes da aplicação de nitrogênio e palha em sistema semeadura direta na cultura do milho Changes in soil properties due to application of nitrogen and straw in maize grown under no-till system

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    Anderson Lange


    Full Text Available Nos últimos anos, tem-se procurado elevar os teores de C orgânico do solo e, ao mesmo tempo, aumentar a produtividade das culturas. Neste contexto, o sistema semeadura direta (SSD tem importante participação, principalmente na região dos Cerrados. Entretanto, para se alcançar altas produtividades, as gramíneas requerem a adição de doses elevadas de adubos nitrogenados. Este trabalho teve por objetivo avaliar as alterações no solo decorrentes da aplicação de palha e de N em solo cultivado com milho por 10 anos (1991-2001 em SSD. O experimento foi desenvolvido na Embrapa-Milho e Sorgo, em Sete Lagoas-MG, em um Latossolo Vermelho distrófico típico sob cerrado. Os tratamentos constaram da combinação de palha sobre o solo (0, 3, 6, 9 e 12Mg ha-1 de matéria seca dispostas nas parcelas, e de cinco níveis de N aplicados em cobertura (0, 40, 80, 120 e 160kg ha-1, na forma de uréia, dispostos nas subparcelas. Foram realizadas duas coletas de solo (antes e após uma calagem, nas profundidades de 0-0,025; 0,025-0,05; 0,05-0,10; 0,10-0,20; 0,20-0,40m. Análises químicas e físicas de rotina foram efetuadas usando-se métodos padrões. Os teores de C orgânico e de K foram influenciados pelas doses de palha e aumentaram à medida que se aumentou a aplicação de palha sobre o solo. A variação nas doses de N promoveu alterações no pH, nos teores de Ca, Mg e nas saturações por bases e por Al até a profundidade de 0,20m. A calagem superficial promoveu o aumento do pH do solo em profundidade e dos teores de Ca, até 0,20m, provavelmente devido à alta pluviosidade no período pós-calagem (1600mm em oito meses.Agricultural practices have been trying to increase the content of organic C in soils and at the same time to increase yields. In this context, the no-till system (NTS has an important role to play, particularly in the Cerrado region of Brazil. However, to reach high yields, the crops demand high inputs of N fertilizers. The

  8. Recomendação de adubação nitrogenada para trigo em sucessão ao silho e soja sob sistema plantio direto no Paraguai Nitrogen fertilizer recommendation for no-till wheat in succession to corn and soybean in Paraguay

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    Ademir Wendling


    Full Text Available O nitrogênio (N é um dos nutrientes mais requeridos pelo trigo e, muitas vezes, não é suprido nem na quantidade nem na época ideal. Devido à importância da adubação nitrogenada no trigo e à carência de informações disponíveis no Paraguai, foi desenvolvido este trabalho com o objetivo de propor uma recomendação nitrogenada para trigo sob sistema plantio direto. Cinco experimentos em rede foram realizados a campo, durante dois anos, em três departamentos do Paraguai, abrangendo os principais solos (Oxisols, Inceptisols e Ultisols e regiões produtoras (Alto Paraná, Itapúa e Missiones. Os tratamentos utilizados no trigo (Triticum aestivum foram cinco doses de N (0, 30, 60, 90 e 120 kg ha-1 após o milho (Zea mays e a soja (Glycine max, sendo também investigado o efeito residual de N aplicado no milho (0, 60, 120, 180 e 240 kg ha-1 na nutrição do trigo, em parcelas de 5 x 8 m, em delineamento de blocos ao acaso com três repetições. O trigo respondeu economicamente, em média, à dose de 35 kg ha-1 de N após a soja para produtividades em torno de 3.100 kg ha-1; após o milho, respondeu economicamente, em média, até 30 kg ha-1 de N, atingindo produtividade de 2.100 kg ha-1. No solo com teor de matéria orgânica maior que 4 %, verificou-se capacidade de suprir, sem adubação nitrogenada mineral, quantidade suficiente de N para alcançar produtividades de até 2.500 kg ha-1. O trigo respondeu à adubação residual de N aplicado no milho, elevando a produtividade de 1.800 (0 kg ha-1 para 2.300 kg ha-1 (com a dose estimada de 213 kg ha-1 de N aplicado no milho, na média de todos os locais.Nitrogen is one of the nutrients wheat needs most, but is often not supplied neither in the right quantity nor at the right time. Because of the importance of nitrogen fertilization and the lack of information available in Paraguay, this study was developed to establish a nitrogen fertilizer recommendation for wheat under no-till. Six

  9. Mycorrhizal colonization, spore density and diversity of arbuscular mycorrhizal fungi in Cerrado soil under no-till and conventional tillage systemsColonização micorrízica, densidade de esporos e diversidade de fungos micorrízicos arbusculares em solo de Cerrado sob plantio direto e convencional

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    José Luiz Rodrigues Torres


    Full Text Available The quest for sustainability in agricultural production through conservation management practices such as no-tillage, has favored the biochemical processes of soil, such as soil arbuscular mycorrhizal fungi (AMFs, which promote a significant increase in specific surface absorption of the root system of plants. The objective of this study was to evaluate the root colonization, spore density and diversity of AMFs in rhizosphere of corn and soybean grown under no-tillage with different cover crops and compared an area conventional tillage and fallow, in Uberaba, state of Minas Gerais. The corn and soybeans were rotated with millet, crotalaria and brachiaria. The experimental design was randomized blocks, with split plots. The experiment was established in 2000, and in 2007 assessed the colonization (COL and spore density (ESP (0.0-0.05m and 0.05-0.10m. In the layer of 0.0-0.10m evaluated the diversity of AMFs. It was found that there was a strong effect of culture on COL and ESP. However, the effect of the covers and management was seen only in 0.0-0.05m. The roots of corn has a higher percentages of COL and ESP compared with soybeans, for the coverage Brachiaria and millet. The mycorrhizal colonization of soybean and maize in Cerrado area was up 80% for soybeans and up 95% for corn. Conventional tillage soil the lowest number of AMFs species in relation to the coverage of millet and Brachiaria in no-till corn and soybeans. The principal components analysis with some chemical, physical and biological factors of soil shows the separation of the areas assessed, and the biological component (COL and ESP in the efficient separation of the areas under cultivation, for the conditions of this study.A busca da sustentabilidade na produção agrícola através de manejos conservacionistas, como o sistema plantio direto, tem favorecido os processos bioquímicos do solo como dos fungos micorrízicos arbusculares (FMAs, os quais promovem um aumento expressivo

  10. Coastal Topography--Northeast Atlantic Coast, Post-Hurricane Sandy, 2012: Lidar-extracted dune features (United States)

    U.S. Geological Survey, Department of the Interior — Dune crest and toe positions along a portion of the New York, Delaware, Maryland, Virginia, and North Carolina coastlines, post-Hurricane Sandy (Sandy was an October...

  11. 2012 U.S. Geological Survey Topographic Lidar: Northeast Atlantic Coast Post-Hurricane Sandy (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Binary point-cloud data were produced for a portion of the New York, Delaware, Maryland, Virginia, and North Carolina coastlines, post-Hurricane Sandy (Sandy was an...

  12. Coastal Topography--Northeast Atlantic Coast, Post-Hurricane Sandy, 2012: Digital elevation model (DEM) (United States)

    U.S. Geological Survey, Department of the Interior — A DEM was produced for a portion of the New York, Delaware, Maryland, Virginia, and North Carolina coastlines, post-Hurricane Sandy (Sandy was an October 2012...

  13. Coastal Topography--Northeast Atlantic Coast, Post-Hurricane Sandy, 2012 (United States)

    U.S. Geological Survey, Department of the Interior — Derived products of a portion of the New York, Delaware, Maryland, Virginia, and North Carolina coastlines, post-Hurricane Sandy (Sandy was an October 2012 hurricane...

  14. Effects of soil amendment on soil characteristics and maize yield in Horqin Sandy Land (United States)

    Zhou, L.; Liu, J. H.; Zhao, B. P.; Xue, A.; Hao, G. C.


    A 4-year experiment was conducted to investigate the inter-annual effects of sandy soil amendment on maize yield, soil water storage and soil enzymatic activities in sandy soil in Northeast China in 2010 to 2014. We applied the sandy soil amendment in different year, and investigated the different effects of sandy soil amendment in 2014. There were six treatments including: (1) no sandy soil amendment application (CK); (2) one year after applying sandy soil amendment (T1); (3) two years after applying sandy soil amendment(T2); (4) three years after applying sandy soil amendment(T3); (5)four years after applying sandy soil amendment(T4); (6) five years after applying sandy soil amendment (T5). T refers to treatment, and the number refers to the year after application of the sandy soil amendment. Comparing with CK, sandy soil amendments improved the soil water storage, soil urease, invertase, and catalase activity in different growth stages and soil layers, the order of soil water storage in all treatments roughly performed: T3 > T5 > T4 > T2 > T1 > CK. the order of soil urease, invertase, and catalase activity in all treatments roughly performed: T5 > T3 > T4 > T2 > T1 > CK. Soil application of sandy soil amendment significantly (p≤⃒0.05) increased the grain yield and biomass yield by 22.75%-41.42% and 29.92%-45.45% respectively, and maize yield gradually increased with the years go by in the following five years. Sandy soil amendment used in poor sandy soil had a positive effect on soil water storage, soil enzymatic activities and maize yield, after five years applied sandy soil amendment (T5) showed the best effects among all the treatments, and deserves further research.

  15. Structural stability and hydraulic conductivity of Nkpologu sandy ...

    African Journals Online (AJOL)


    single grain structure at the surface. The soils are predominantly sandy in texture with sand weighted average values of > 90 % in Sokoto and Illela coversand and > 80 % in Sangiwa coversand. The soils were acidic with pH values ranging from 4.6 to 5.4. Organic matter, exchangeable bases, CEC and base saturation were ...

  16. Effect of Tractor Forward Speed on Sandy Loam Soil Physical ...

    African Journals Online (AJOL)

    Field studies were conducted at the National Centre for Agricultural Mechanization (NCAM), Ilorin on a sandy loam soil to evaluate the effect of the imposition of different levels of tractor forward speed during tillage on some soil physical properties. The forward speed was varied from 1.0 to 10.6km/h: The depth of tillage was ...

  17. Compaction Behaviour of Akure Sandy Clay Loamy Soils | Manuwa ...

    African Journals Online (AJOL)

    Laboratory investigations were conducted to study the behaviors of sandy clay loam soil under uni-axial compression loading. The effects of applied pressure and moisture content on bulk density of soils were observed and subjected to regression analysis. The effect of applied pressure on bulk density could be described ...

  18. Microfungi diversity isolation from sandy soil of Acapulco touristic beaches (United States)

    Microscopic fungi diversity in marine sandy soil habitats is associated with key functions of beach ecosystems. There are few reports on their presence in Mexican beaches. Although standard methods to obtain the fungi from soil samples are established, the aim of this pilot study was to test the pla...

  19. Stability analysis of sandy slope considering anisotropy effect in ...

    Indian Academy of Sciences (India)

    This paper aims to investigate the effect of anisotropy of shear strength parameter on the stability of a sandy slope by performing the limit equilibrium analysis. Because of scarcity of mathematical equation for anisotropic friction angle of sand, at first, all results of principal stress rotation tests are processed by artificial neural ...

  20. effect of tractor forward speed on sandy loam soil physical ...

    African Journals Online (AJOL)

    Dr Obe

    . 51 ... Ilorin on a sandy loam soil to evaluate the effect of the imposition of different levels of tractor forward speed during tillage on some soil physical .... reported to have negative impacts to root growth and development (Negi; et al., 1980,.

  1. Organisms associated with the sandy-beach bivalve Donax serra ...

    African Journals Online (AJOL)

    the two trematode species found is described as new and its epidemiology is discussed briefly. No epibiota were found on the bivalve shell. *To whom correspondence should be addressed. The macrofauna of sandy beaches around South Africa is now well known, the dominant white sand mussel, Donax serra, being a ...

  2. Rapid Assessment of Anthropogenic Impacts on Exposed Sandy ...

    African Journals Online (AJOL)


    beach population: the wedge clam Donax hanleyanus in Uruguay. Marine Ecology. Progress Series, 123: 73-82. GHAPOHA, 2010. Tide tables. Ghana Ports and Harbours Authority. Tema. Guald, D. T & Buchanan. 1956. The fauna of sandy beaches in the Gold Coast. Oikos, 7: 293-301. Farrelly, C. A & Greenaway, P. 1994.

  3. Leaching behaviour of azoxystrobin in sandy loam soil

    African Journals Online (AJOL)

    Mr HMM Mzimela


    Aug 1, 2014 ... Key words: Leaching, azoxystrobin, sandy loam soil, column, residues. INTRODUCTION. Pesticides are one of the major technological developments of twentieth century. Whether natural or synthetic, they have toxicological significance and pose a potential risk when they persist in the environment. The.

  4. The Sandy Hook Elementary School shooting as tipping point (United States)

    Shultz, James M; Muschert, Glenn W; Dingwall, Alison; Cohen, Alyssa M


    Among rampage shooting massacres, the Sandy Hook Elementary School shooting on December 14, 2012 galvanized public attention. In this Commentary we examine the features of this episode of gun violence that has sparked strong reactions and energized discourse that may ultimately lead toward constructive solutions to diminish high rates of firearm deaths and injuries in the United States. PMID:28228989

  5. Growth and production of Bullia rhodostoma on an open sandy ...

    African Journals Online (AJOL)

    The plough shell, Bul/ia rhodostoma (Mollusca: Gastropoda), has been studied on an open sandy beach where it is a common scavenger. Samples taken over a year indicate hatching of young individuals from December to February. They reach a length of about 10 mm after 1 year and 40 mm after 10 years. The von ...

  6. Stability analysis of sandy slope considering anisotropy effect in ...

    Indian Academy of Sciences (India)

    strength anisotropy. Finally, considering the variability of soil shear strength parameters with loading orientation, the stability of a sandy slope with various geometries is analyzed by the limit equilibrium .... The participant of training, testing and validation subsets from the whole of records are 70, 15 and 15%, respectively.

  7. Structural Stability and Hydraulic Conductivity Of Nkpologu Sandy ...

    African Journals Online (AJOL)

    Studies were conducted in the runoff plots at the University of Nigeria Nsukka Teaching and Resesarch Farm in 2010 and 2011 to monitor the changes in structural stability and saturated hydraulic conductivity (Ksat) of Nkpologu sandy loam soil under different cover management practices. The management practices were ...

  8. Hurricane Sandy: An Educational Bibliography of Key Research Studies (United States)

    Piotrowski, Chris


    There, undoubtedly, will be a flurry of research activity in the "Superstorm" Sandy impact area on a myriad of disaster-related topics, across academic disciplines. The purpose of this study was to review the disaster research related specifically to hurricanes in the educational and social sciences that would best serve as a compendium…

  9. Microplastics in coastal and marine environments of the western tropical and sub-tropical Atlantic Ocean. (United States)

    Costa, Monica F; Barletta, Mário


    Microplastic pollution is a global issue. It is present even in remote and pristine coastal and marine environments, likely causing impacts of unknown scale. Microplastics are primary- and secondary-sourced plastics with diameters of 5 mm or less that are either free in the water column or mixed in sandy and muddy sediments. Since the early 1970s, they have been reported to pollute marine environments; recently, concern has increased as soaring amounts of microplastics in the oceans were detected and because the development of unprecedented processes involving this pollutant at sea is being unveiled. Coastal and marine environments of the western tropical and sub-tropical Atlantic Ocean (WTAO) are contaminated with microplastics at different quantities and from a variety of types. The main environmental compartments (water, sediments and biota) are contaminated, but the consequences are still poorly understood. Rivers and all scales of fishery activities are identified as the most likely sources of this pollutant to coastal waters; however, based on the types of microplastics observed, other maritime operations are also possible sources. Ingestion by marine biota occurs in the vertebrate groups (fish, birds, and turtles) in these environments. In addition, the presence of microplastics in plankton samples from different habitats of estuaries and oceanic islands is confirmed. The connectivity among environmental compartments regarding microplastic pollution is a new research frontier in the region.

  10. Imobilização de nitrogênio da uréia e do sulfato de amônio aplicado em pré-semeadura ou cobertura na cultura de milho, no sistema plantio direto Nitrogen immobilization of urea and ammonium sulphate applied to maize before planting or top-dressing in a no-till system

    Directory of Open Access Journals (Sweden)

    Waldo Alejandro Ruben Lara Cabezas


    valores foram, respectivamente, de 4,5 e 5,2 kg ha-1, mostrando menor proporção de N-imobilizado de SA, com a aplicação dos fertilizantes em cobertura. As produtividades de grãos obtidas com SA e U, independentemente da época de aplicação, foram de 8.543 e 7.767 kg ha-1, respectivamente. Na adubação em pré-semeadura do milho, o SA apresentou maior rapidez na ciclagem do N imobilizado-mineralizado (turnover, em relação a U, e, conseqüentemente, causou maior absorção do N pela cultura, como verificado na safra anterior. Em cobertura, no sulco de adubação, de forma similar à observada na safra anterior, somente houve imobilização significativa do N-U, retardando sua absorção pela planta.Ammonium sulfate (AS and urea (U, labeled with 15N, were applied to no-till maize, 33 days before and 10 days after sowing, at a single rate of 80 kg ha-1 of N incorporated 5-7 cm deep along furrows spaced 0.8 m. Corn was sown after black oat (Avena strigosa Schieb..The amount of immobilized N and of N-fertilizer recovered by corn plants was evaluated at the following plants stages: 4-5 leaves, 11-12 leaves, flowering, and at harvest. Treatments were applied in a randomized block design with three replications. The analysis of variance was performed based on one factorial scheme (2 x 6 with two sources in pre-planting (AS and U on six sampling dates, and on a second (2 x 3 with two sources in top-dressing on three sampling dates. This field experiment was carried out on a Typic Acrustox in Uberlandia, Minas Gerais state, Brazil. Pre-planting applications resulted in a maximal AS-N immobilization 22 days after fertilizer application (9.1 kg ha-1 or 11.4 % of applied N, whereas the maximum immobilization of U-N occurred 11 days after fertilizer application (46.5 kg ha-1 or 58.1 % of applied N. Until harvest, the plants (aerial part, grains and roots had accumulated 66.0 and 47.9 of AS-N and U-N, respectively (use efficiency of 82.5 and 59.9 % of applied N. N top

  11. Imobilização de nitrogênio da uréia e do sulfato de amônio aplicado em pré-semeadura ou cobertura na cultura de milho, no sistema plantio direto Nitrogen immobilization of urea and ammonium sulphate applied to maize before planting and as top-dressing in a no-till system

    Directory of Open Access Journals (Sweden)

    Waldo Alejandro Ruben Lara Cabezas


    SA e U, independentemente da época de aplicação, foram de 7.824 kg ha-1 e 6.977 kg ha-1, respectivamente. Na adubação em pré-semeadura do milho, o SA apresentou maior rapidez na ciclagem do N imobilizado-mineralizado ("turnover", em relação a U, e, conseqüentemente, causou maior assimilação do N pela cultura. Em cobertura, no sulco de adubação, somente houve imobilização do N-U, retardando a sua assimilação pela planta.In order to evaluate the amount of immobilized N and the amount of N-fertilizer recovered by corn plants at the stages:5-6 leaves, 11-12 leaves, flowering, and physiologic maturation, ammonium sulfate (AS and urea (U, labeled with 15N, were applied to maize in a no-till system 43 days before planting and 31 days after planting at a single rate of 80 kg ha-1 of N incorporated at 5-7 cm depth and in a spacing of 0.8 m. Corn was sown after black oat (Avena strigosa Schieb.. The treatments were applied in split-plots set up in the completely randomized design with three replications. The original plots with two N sources were halved for the application time factor (pre-planting and top-dressing application. The field experiment was carried out on a Typic Acrustox on the farm Floresta do Lobo, Uberlandia, state of Minas Gerais. Results show that in pre-planting application treatments the maximum N-AS immobilization occurred 19 days after the fertilizer application (13.3 kg ha-1 or 16.6 % of N applied whereas the maximum immobilization of N-U occurred 40 days after fertilizer application (13.7 kg ha-1 or 17.1 % of N applied. The highest amount of 15N-fertilizer taken up by corn plants was observed between the stages 5-6 leaves and 11-12 leaves, at ratios of 44.1 % of N-AS and 23.4 % of N-U. The immobilized N in the treatment with top-dressed AS was lower than 3.5 % of the applied N whereas in the treatment with top-dressed U it was 9.9 kg ha-1 and 7.9 kg ha-1 at the stages 11-12 leaves and flowering, respectively. The recovery of N

  12. A re-examination of the projected subtropical precipitation decline (United States)

    He, Jie; Soden, Brian J.


    A large-scale precipitation decline in the subtropics is a widely accepted projection of future climate change, but its causes and implications are uncertain. Two mechanisms are commonly used to explain the large-scale subtropical precipitation decline: an amplification of moisture export due to the increase in moisture and a poleward shift of subtropical subsidence associated with the poleward expansion of the Hadley cell. In an idealized experiment with abrupt CO2 increase, we find that the subtropical precipitation decline forms primarily in the fast adjustment to CO2 forcing during which neither of the two proposed mechanisms exists. Permitting the increase in moisture and the Hadley cell expansion does not substantially change the characteristics of the large-scale subtropical precipitation decline. This precipitation change should be interpreted as a response to the land-sea warming contrast, the direct radiative forcing of CO2 and, in certain regions, the pattern of SST changes. Moreover, the subtropical precipitation decline is projected predominately over oceans. Over subtropical land regions, the precipitation decline is muted or even reversed by the land-sea warming contrast.

  13. Superstorm Sandy and the Verdant Power RITE Project (United States)

    Corren, D.; Colby, J.; Adonizio, M.


    On October 29, 2012 Superstorm Sandy (formerly Hurricane Sandy) made landfall in New Jersey. One of the deadliest, and second-costliest hurricane in US history, Sandy was the largest Atlantic hurricane on record, with a diameter of 1,800 km. It was this unprecedented size, extreme central low pressure, and full-moon timing that created a storm surge which inundated New York City with record-breaking water levels, resulting in tremendous destruction of buildings and infrastructure. At its RITE (Roosevelt Island Tidal Energy) Project in New York City's East River, Verdant Power has been installing demonstration and commercial turbine systems since 2005, along with performing related environmental monitoring and measurements. The RITE site is located in the East Channel of the East River, on the east side of Roosevelt Island. All along the East River, large areas of the adjacent boroughs were impacted by Sandy, including flooding of the subway tunnels under the river. When Sandy struck, Verdant had recently concluded a two-week in-water test at RITE of a new rotor for its Gen5 KHPS (Kinetic Hydropower System) turbine, with funding assistance by partners NYSERDA and the US Department of Energy. While the turbine had already been removed from its mounting in the river bottom in September, Verdant continued to operate two water measurement instruments in the river. These acoustic Doppler current profilers (ADCPs) measure the 3-D water velocity at various heights in the water column, and are also equipped to provide water level data. Verdant is interested in the effects such an extreme storm could have on turbines and other equipment installed in this river reach, as is planned by Verdant under a 10-year commercial pilot project licensed by the Federal Energy Regulatory Commission (FERC) for up to 30 turbines. Associated equipment includes navigational aids (buoys and signage), which Verdant is required to maintain to exclude vessels from the project boundaries. The East

  14. Hurricane Sandy's flood frequency increasing from year 1800 to 2100. (United States)

    Lin, Ning; Kopp, Robert E; Horton, Benjamin P; Donnelly, Jeffrey P


    Coastal flood hazard varies in response to changes in storm surge climatology and the sea level. Here we combine probabilistic projections of the sea level and storm surge climatology to estimate the temporal evolution of flood hazard. We find that New York City's flood hazard has increased significantly over the past two centuries and is very likely to increase more sharply over the 21st century. Due to the effect of sea level rise, the return period of Hurricane Sandy's flood height decreased by a factor of ∼3× from year 1800 to 2000 and is estimated to decrease by a further ∼4.4× from 2000 to 2100 under a moderate-emissions pathway. When potential storm climatology change over the 21st century is also accounted for, Sandy's return period is estimated to decrease by ∼3× to 17× from 2000 to 2100.

  15. Subtropical Dust Storms and Downslope Wind Events (United States)

    Pokharel, Ashok Kumar; Kaplan, Michael L.; Fiedler, Stephanie


    We performed detailed mesoscale observational analyses and Weather Research and Forecasting (WRF) model simulations to study the terrain-induced downslope winds that generated dust-emitting winds at the beginning of three strong subtropical dust storms in three distinctly different regions of North Africa and the Arabian Peninsula. We revisit the Harmattan dust storm of 2 March 2004, the Saudi dust storm of 9 March 2009, and the Bodélé Depression dust storm of 8 December 2011 and use high-resolution WRF modeling to assess the dynamical processes during the onset of the storms in more depth. Our results highlight the generation of terrain-induced downslope winds in response to the transition of the atmospheric flow from a subcritical to supercritical state in all three cases. These events precede the unbalanced adjustment processes in the lee of the mountain ranges that produced larger-scale dust aerosol mobilization and transport. We see that only the higher-resolution data sets can resolve the mesoscale processes, which are mainly responsible for creating strong low-level terrain-induced downslope winds leading to the initial dust storms.

  16. Hurricane Sandy washover deposits on Fire Island, New York (United States)

    La Selle, SeanPaul M.; Lunghino, Brent D.; Jaffe, Bruce E.; Gelfenbaum, Guy; Costa, Pedro J.M.


    Washover deposits on Fire Island, New York, from Hurricane Sandy in 2012 were investigated a year after the storm to document the sedimentary characteristics of hurricane washover features. Sediment data collected in the field includes stratigraphic descriptions and photos from trenches, bulk sediment samples, U-channels, and gouge and push cores. Samples and push cores were further analyzed in the laboratory for grain size, density variations using x-ray computed tomography (CT), and surface microtexture using a scanning electron microscope (SEM). Elevation profiles of washover features were measured using Differential Global Positioning System (DGPS) with Real Time Kinematic processing. The DGPS elevations were compared to lidar (light detection and ranging) data from pre- and post-Sandy surveys to assess the degree to which washover deposit thicknesses changed within the year following deposition. Hurricane Sandy washover deposits as much as 1 meter thick were observed in trenches. Initial results show that the upper parts of the deposits have been reworked significantly in some places by wind, but there are still areas where the deposits are almost entirely intact. Where mostly intact, the washover deposits consist of massive or weakly laminated sand near the base, overlain by more strongly laminated sands.

  17. Brazilian sandy beaches: characteristics, ecosystem services, impacts, knowledge and priorities

    Directory of Open Access Journals (Sweden)

    Antonia Cecília Zacagnini Amaral

    Full Text Available ABSTRACT Sandy beaches constitute a key ecosystem and provide socioeconomic goods and services, thereby playing an important role in the maintenance of human populations and in biodiversity conservation. Despite the ecological and social importance of these ecosytems, Brazilian sandy beaches are significantly impacted by human interference, chemical and organic pollution and tourism, as well as global climate change. These factors drive the need to better understand the environmental change and its consequences for biota. To promote the implementation of integrated studies to detect the effects of regional and global environmental change on beaches and on other benthic habitats of the Brazilian coast, Brazilian marine researchers have established The Coastal Benthic Habitats Monitoring Network (ReBentos. In order to provide input for sample planning by ReBentos, we have conducted an intensive review of the studies conducted on Brazilian beaches and summarized the current knowledge about this environment. In this paper, we present the results of this review and describe the physical, biological and socioeconomics features of Brazilian beaches. We have used these results, our personal experience and worldwide literature to identify research projects that should be prioritized in the assessment of regional and global change on Brazilian sandy beaches. We trust that this paper will provide insights for future studies and represent a significant step towards the conservation of Brazilian beaches and their biodiversity.

  18. Longitudinal Impact of Hurricane Sandy Exposure on Mental Health Symptoms. (United States)

    Schwartz, Rebecca M; Gillezeau, Christina N; Liu, Bian; Lieberman-Cribbin, Wil; Taioli, Emanuela


    Hurricane Sandy hit the eastern coast of the United States in October 2012, causing billions of dollars in damage and acute physical and mental health problems. The long-term mental health consequences of the storm and their predictors have not been studied. New York City and Long Island residents completed questionnaires regarding their initial Hurricane Sandy exposure and mental health symptoms at baseline and 1 year later (N = 130). There were statistically significant decreases in anxiety scores (mean difference = -0.33, p stress disorder (PTSD) scores (mean difference = -1.98, p = 0.001) between baseline and follow-up. Experiencing a combination of personal and property damage was positively associated with long-term PTSD symptoms (ORadj 1.2, 95% CI [1.1-1.4]) but not with anxiety or depression. Having anxiety, depression, or PTSD at baseline was a significant predictor of persistent anxiety (ORadj 2.8 95% CI [1.1-6.8], depression (ORadj 7.4 95% CI [2.3-24.1) and PTSD (ORadj 4.1 95% CI [1.1-14.6]) at follow-up. Exposure to Hurricane Sandy has an impact on PTSD symptoms that persists over time. Given the likelihood of more frequent and intense hurricanes due to climate change, future hurricane recovery efforts must consider the long-term effects of hurricane exposure on mental health, especially on PTSD, when providing appropriate assistance and treatment.

  19. Longitudinal Impact of Hurricane Sandy Exposure on Mental Health Symptoms

    Directory of Open Access Journals (Sweden)

    Rebecca M. Schwartz


    Full Text Available Hurricane Sandy hit the eastern coast of the United States in October 2012, causing billions of dollars in damage and acute physical and mental health problems. The long-term mental health consequences of the storm and their predictors have not been studied. New York City and Long Island residents completed questionnaires regarding their initial Hurricane Sandy exposure and mental health symptoms at baseline and 1 year later (N = 130. There were statistically significant decreases in anxiety scores (mean difference = −0.33, p < 0.01 and post-traumatic stress disorder (PTSD scores (mean difference = −1.98, p = 0.001 between baseline and follow-up. Experiencing a combination of personal and property damage was positively associated with long-term PTSD symptoms (ORadj 1.2, 95% CI [1.1–1.4] but not with anxiety or depression. Having anxiety, depression, or PTSD at baseline was a significant predictor of persistent anxiety (ORadj 2.8 95% CI [1.1–6.8], depression (ORadj 7.4 95% CI [2.3–24.1 and PTSD (ORadj 4.1 95% CI [1.1–14.6] at follow-up. Exposure to Hurricane Sandy has an impact on PTSD symptoms that persists over time. Given the likelihood of more frequent and intense hurricanes due to climate change, future hurricane recovery efforts must consider the long-term effects of hurricane exposure on mental health, especially on PTSD, when providing appropriate assistance and treatment.

  20. Sandy Soil Microaggregates: Rethinking Our Understanding of Hydraulic Function

    Energy Technology Data Exchange (ETDEWEB)

    Paradiś, Ashley; Brueck, Christopher; Meisenheimer, Douglas; Wanzek, Thomas; Dragila, Maria Ines


    This study investigated the peculiar structure of microaggregates in coarse sandy soils that exhibit only external porosity and investigated their control on soil hydrology. The microstructure underpins a hydrologic existence that differs from finer textured soils where aggregates have internal porosity. Understanding the impact of these microaggregates on soil hydrology will permit improved agricultural irrigation management and estimates associated with ecosystem capacity and resiliency. Microstructure was investigated using a digital microscope, and aspects of the structure were quantified by sedimentation and computed microtomography. Sandy soil microaggregates were observed to be comprised of a solid sand-grain core that is coated with fines, presumably cemented by organic media. This microstructure leads to three distinct water pools during drainage: capillary water, followed by thick films (1–20 μm) enveloping the outer surfaces of the crusted microaggregates, followed by adsorbed thin films (<1 μm). The characteristics of the thick films were investigated using an analytical model. These films may provide as much as 10 to 40% saturation in the range of plant-available water. Using lubrication theory, it was predicted that thick film drainage follows a power law function with an exponent of 2. Thick films may also have a role in the geochemical evolution of soils and in ecosystem function because they provide contiguous water and gas phases at relatively high moisture contents. And, because the rough outer crust of these microaggregates can provide good niches for microbial activity, biofilm physics will dominate thick film processes, and consequently hydrologic, biologic, and geochemical functions for coarse sandy soils.

  1. Impact of Hurricane Sandy on salt marshes of New jersey (United States)

    Elsey-Quirk, Tracy


    Hurricane Sandy, one of the largest Atlantic hurricanes on record, made landfall as an extratropical cyclone on the coast of New Jersey (29 October 2012) along a track almost perpendicular to the coast. Ten days later a northeaster caused heavy precipitation and elevated water levels along the coast. Two years of pre-storm monitoring and research in marshes of Barnegat Bay and the Delaware Estuary provided an opportunity to evaluate the impacts of Hurricane Sandy and the succeeding northeaster across the region. Peak water levels during Sandy ranged from 111 to 184 cm above the marsh surface in Barnegat Bay and 75-135 cm above the marsh surface in the Delaware Estuary. Despite widespread flooding and damage to coastal communities, the storm had modest and localized impacts on coastal marshes of New Jersey. Measurements made on the marsh platform illustrated localized responses to the storms including standing biomass removal, and changes in peak biomass the following summer. Marsh surface and elevation changes were variable within marshes and across the region. Localized elevation changes over the storm period were temporary and associated with subsurface processes. Over the long-term, there was no apparent impact of the 2012 storms, as elevations and regression slopes pre- and several months post-storm were not significant. Vegetation changes in the summer following the fall 2012 storms were also variable and localized within and among marshes. These results suggest that Hurricane Sandy and the succeeding northeaster did not have a widespread long-term impact on saline marshes in this region. Possible explanations are the dissipation of surge and wave energy from the barrier island in Barnegat Bay and the extreme water levels buffering the low-lying marsh surface from waves, winds, and currents, and carrying suspended loads past the short-statured marsh grasses to areas of taller vegetation and/or structure. These findings demonstrate that major storms that have

  2. Crop Growing by Brackish Water Drip Irrigaton in Sandy Soil


    山根, 昌勝; 佐藤, 一郎


    Grain sorghum(Sorghum vulgare L.),cabbage (Brassica oleracea L.)and Japanese radish(Raphanus sativus L.)were grown in sandy soil under a plastic house,and irrigated either with fresh water, or with brackish water containing 2995 ppm of several dissolved salts,a nd using five kinds of drip irrigation emitters. The soil moisture contents of the brackish water plots were slight1l higher than those of the fresh water plots. In the brackish water plots,the pH values of soil suspension (H₂0,1:2.5) ...

  3. Large-Scale Experiments in a Sandy Aquifer in Denmark

    DEFF Research Database (Denmark)

    Jensen, Karsten Høgh; Bitsch, Karen Bue; Bjerg, Poul Løgstrup


    A large-scale natural gradient dispersion experiment was carried out in a sandy aquifer in the western part of Denmark using tritium and chloride as tracers. For both plumes a marked spreading was observed in the longitudinal direction while the spreading in the transverse horizontal and transverse...... vertical directions was very small. The horizontal transport parameters of the advection-dispersion equation were investigated by applying an optimization model to observed breakthrough curves of tritium representing depth averaged concentrations. No clear trend in dispersion parameters with travel...

  4. Remediation of Diesel Fuel Contaminated Sandy Soil using Ultrasonic Waves

    Directory of Open Access Journals (Sweden)

    Wulandari P.S.


    Full Text Available Ultrasonic cleaning has been used in industry for some time, but the application of ultrasonic cleaning in contaminated soil is just recently received considerable attention, it is a very new technique, especially in Indonesia. An ultrasonic cleaner works mostly by energy released from the collapse of millions of microscopic cavitations near the dirty surface. This paper investigates the use of ultrasonic wave to enhance remediation of diesel fuel contaminated sandy soil considering the ultrasonic power, soil particle size, soil density, water flow rate, and duration of ultrasonic waves application.

  5. Late Pleistocene glacial fluctuations in Cordillera Oriental, subtropical Andes (United States)

    Martini, Mateo A.; Kaplan, Michael R.; Strelin, Jorge A.; Astini, Ricardo A.; Schaefer, Joerg M.; Caffee, Marc W.; Schwartz, Roseanne


    The behavior of subtropical glaciers during Middle to Late Pleistocene global glacial maxima and abrupt climate change events, specifically in Earth's most arid low-latitude regions, remains an outstanding problem in paleoclimatology. The present-day climate of Cordillera Oriental, in arid northwestern Argentina, is influenced by shifts in subtropical climate systems, including the South American Summer Monsoon. To understand better past glacier-subtropical climates during the global Last Glacial Maximum (LGM, 26.5-19 ka) and other time periods, we combined geomorphic features with forty-two precise 10Be ages on moraine boulders and reconstructed paleo-equilibrium line altitudes (ELA) at Nevado de Chañi (24°S) in the arid subtropical Andes. We found a major glacial expansion at ∼23 ± 1.6 ka, that is, during the global LGM. Additional glacial expansions are observed before the global LGM (at ∼52-39 ka), and after, at 15 ± 0.5 and 12 ± 0.6 ka. The ∼15 ka glacial event was found on both sides of Chañi and the ∼12 ka event is only recorded on the east side. Reconstructed ELAs of the former glaciers exhibit a rise from east to west that resembles the present subtropical climate trajectory from the Atlantic side of the continent; hence, we infer that this climate pattern must have been present in the past. Based on comparison with other low-latitude paleoclimate records, such as those from lakes and caves, we infer that both temperature and precipitation influenced past glacial occurrence in this sector of the arid Andes. Our findings also imply that abrupt deglacial climate events associated with the North Atlantic, specifically curtailed meridional overturning circulation and regional cooling, may have had attendant impacts on low subtropical Southern Hemisphere latitudes, including the climate systems that affect glacial activity around Nevado de Chañi.

  6. The Ocean deserts:salt budgets of northern subtropical oceans and their

    KAUST Repository

    Carton, Jim


    The Ocean deserts: salt budgets of northern subtropical oceans and their relationship to climate variability The high salinity near surface pools of the subtropical oceans are the oceanic deserts, with high levels of evaporation and low levels of precip

  7. The bioremediation potential of marine sandy sediment microbiota

    Directory of Open Access Journals (Sweden)

    Dan Răzvan POPOVICIU


    Full Text Available The natural microbiota from marine sandy sediments on the Romanian sea coast was tested for resilience in case of hydrocarbon contamination, for estimating the number of (culturable hydrocarbon and lipid oil-degrading microorganisms and for determining the influence of inorganic nitrate and phosphate nutrients on hydrocarbon spill bioremediation process, by microcosm experiments.Results show that hydrocarbon contamination affects the bacteriobenthos both in terms of cell numbers and composition. Bacterial numbers showed a rapid decrease (28% in four days, followed by a relatively fast recovery (two weeks. The pollution favoured the increase of Gram-positive bacterial proportion (from around 25% to 33%Sandy sediment microbiota in both sites studied contained microorganisms able to use mineral or lipid oils as sole carbon sources, usually around 103-104/cm3, with variations according to the sediment grain size and substrate used.The biostimulation experiments showed that, in absence of water dynamism (and, implicitly, an efficient oxygenation, the addition of nitrogen and phosphorus can be ineffective and even inhibit the remediation process, probably due to eutrophication.

  8. Superstorm Sandy and the academic achievement of university students. (United States)

    Doyle, Matthew D; Lockwood, Brian; Comiskey, John G


    Much of the literature on the consequences of natural disasters has focused on their physical and psychological ramifications. Few researchers have considered how the impacts of a natural disaster can influence academic achievement. This study analyses data collected from nearly 300 students at a mid-sized, private university in the northeast United States to determine if the effects of Cyclone Sandy in 2012 are associated with measures of academic achievement. The findings reveal that experiencing headaches after the event resulted in a higher likelihood of students suffering a loss of academic motivation. In addition, experiencing headaches and a loss of academic motivation were correlated with a lower grade point average (GPA) during the semester in which Sandy made landfall. However, the more direct effects of the superstorm, including displacement and a loss of power, did not have a significant bearing on academic achievement. Lastly, the paper examines the implications for higher education policy and future research. © 2017 The Author(s). Disasters © Overseas Development Institute, 2017.

  9. Quality Assurance After a Natural Disaster: Lessons from Hurricane Sandy. (United States)

    Dickerson, Collin; Hsu, Yanshen; Mendoza, Sandra; Osman, Iman; Ogilvie, Jennifer; Patel, Kepal; Moreira, Andre L


    Biospecimen quality can vary depending on many pre- and post-collection variables. In this study, we consider a natural disaster as a post-collection variable that may have compromised the quality of frozen tissue specimens. To investigate this possible link, we compared the quality of nucleic acids, the level of antigenicity, and the preservation of histology from frozen specimens collected before and after the power outage caused by Hurricane Sandy. To analyze nucleic acid quality, we extracted both DNA and RNA and performed capillary electrophoresis to compare the quality and concentrations of the nucleic acids. To compare antigenicity, frozen sections were cut and immunostained for thyroid transcription factor 1 (TTF-1), a nuclear transcription protein commonly used as a diagnostic biomarker for multiple cancer types, including thyroid and lung cancers. Positive expression of TTF-1, as noted by homogenous nuclear staining, would demonstrate that the TTF-1 proteins could still bind antibodies and, therefore, that these proteins were not significantly degraded. Furthermore, representative frozen sections stained with hematoxylin and eosin were also assessed qualitatively by a trained pathologist to examine any possible histologic aberrations. Due to the similar quality of the tissue samples collected before and after the storm, Hurricane Sandy had no discernable effect on the quality of frozen specimens, and these specimens exposed to the natural disaster are still valuable research tools.

  10. Evaluation of environmental quality of sandy beaches in southeastern Brazil. (United States)

    Suciu, Marjorie C; Tavares, Davi C; Costa, Leonardo L; Silva, Marianna C L; Zalmon, Ilana R


    The effect of urbanization on the environmental quality of two sandy beaches was evaluated using metrics such as pH, dissolved oxygen, coliforms and solid waste. Urbanization effects on physicochemical metrics (pH and dissolved oxygen) were not significant. The coliforms concentration was below the established limit for primary contact, but it was significantly higher on beaches with highest recreational potential. Similarly, the abundance of solid waste was significantly higher in urbanized areas (~4.5 items/m2), and it was higher than what was found for 106 beaches worldwide. Plastic represented 84% of the total number of items and recreational activities were the main sources of debris (80%). Therefore, a balance between recreation and conservation actions, based on short-term (e.g. fines) and long-term measures (e.g. educational policies) is recommended. We demonstrate that the use of multiple metrics provides more robust estimates of the environmental quality of sandy beaches than a single impact metric. Copyright © 2017. Published by Elsevier Ltd.

  11. A Coordinated USGS Science Response to Hurricane Sandy (United States)

    Jones, S.; Buxton, H. T.; Andersen, M.; Dean, T.; Focazio, M. J.; Haines, J.; Hainly, R. A.


    In late October 2012, Hurricane Sandy came ashore during a spring high tide on the New Jersey coastline, delivering hurricane-force winds, storm tides exceeding 19 feet, driving rain, and plummeting temperatures. Hurricane Sandy resulted in 72 direct fatalities in the mid-Atlantic and northeastern United States, and widespread and substantial physical, environmental, ecological, social, and economic impacts estimated at near $50 billion. Before the landfall of Hurricane Sandy, the USGS provided forecasts of potential coastal change; collected oblique aerial photography of pre-storm coastal morphology; deployed storm-surge sensors, rapid-deployment streamgages, wave sensors, and barometric pressure sensors; conducted Light Detection and Ranging (lidar) aerial topographic surveys of coastal areas; and issued a landslide alert for landslide prone areas. During the storm, Tidal Telemetry Networks provided real-time water-level information along the coast. Long-term networks and rapid-deployment real-time streamgages and water-quality monitors tracked river levels and changes in water quality. Immediately after the storm, the USGS serviced real-time instrumentation, retrieved data from over 140 storm-surge sensors, and collected other essential environmental data, including more than 830 high-water marks mapping the extent and elevation of the storm surge. Post-storm lidar surveys documented storm impacts to coastal barriers informing response and recovery and providing a new baseline to assess vulnerability of the reconfigured coast. The USGS Hazard Data Distribution System served storm-related information from many agencies on the Internet on a daily basis. Immediately following Hurricane Sandy the USGS developed a science plan, 'Meeting the Science Needs of the Nation in the Wake of Hurricane Sandy-A U.S. Geological Survey Science Plan for Support of Restoration and Recovery'. The plan will ensure continuing coordination of internal USGS activities as well as

  12. Buoyancy-stirring interactions in a subtropical embayment: a ...

    African Journals Online (AJOL)

    ... were ~2–3 °C higher than those observed. The model also underestimated the intensity of stratification in the wet season. These shortcomings all suggest an overestimate of vertical mixing by the model's turbulence closure scheme. Keywords: buoyancy; density gradient; Maputo Bay; seasonal variation; subtropical zone; ...

  13. Effect of soil pH on sorption of salinomycin in clay and sandy soils

    African Journals Online (AJOL)


    In this study, sorption of salinomycin was measured in four agricultural soils, a clay soil with low organic matter content (LOM), a clay soil with high organic matter content (HOM), a sandy soil with. HOM, and a loamy sandy (LOM) soils, at three pH levels, namely 4, 7 and 9. Desorption studies was carried out using the batch ...

  14. Abrasive wear based predictive maintenance for systems operating in sandy conditions

    NARCIS (Netherlands)

    Woldman, M.; Tinga, Tiedo; van der Heide, Emile; Masen, Marc Arthur


    Machines operating in sandy environments are damaged by the abrasive action of sand particles that enter the machine and become entrapped between components and contacting surfaces. In the case of the military services the combination of a sandy environment and the wide range of tasks to be

  15. Validation of regression models for nitrate concentrations in the upper groundwater in sandy soils

    NARCIS (Netherlands)

    Sonneveld, M.P.W.; Brus, D.J.; Roelsma, J.


    For Dutch sandy regions, linear regression models have been developed that predict nitrate concentrations in the upper groundwater on the basis of residual nitrate contents in the soil in autumn. The objective of our study was to validate these regression models for one particular sandy region

  16. Profile distribution of total and available Sulphur and boron in sandy ...

    African Journals Online (AJOL)

    The total and available sulphur and boron forms were determined in sandy soils formed from sand dunes, sandy alluvial terrace and sandstone formation in northwestern Nigeria. Hot water and Morgan's solution (sodium acetate/acetic acid solution buffered at pH 4.8) were used as extractants for available boron while ...

  17. 76 FR 64341 - Big Sandy Pipeline, LLC; Notice of Cost and Revenue Study (United States)


    ... Energy Regulatory Commission Big Sandy Pipeline, LLC; Notice of Cost and Revenue Study Take notice that on April 8, 2011, Big Sandy Pipeline, LLC filed its cost and revenue study in compliance with the... or before the date as indicated below. Anyone filing a protest must serve a copy of that document on...

  18. Measuring Sandy Bottom Dynamics by Exploiting Depth from Stereo Video Sequences

    DEFF Research Database (Denmark)

    Musumeci, Rosaria E.; Farinella, Giovanni M.; Foti, Enrico


    In this paper an imaging system for measuring sandy bottom dynamics is proposed. The system exploits stereo sequences and projected laser beams to build the 3D shape of the sandy bottom during time. The reconstruction is used by experts of the field to perform accurate measurements and analysis...

  19. Effects Of Mixtures Of Pig Manure And Sandy Soil On The Growth Of ...

    African Journals Online (AJOL)

    A study was carried out to evaluate the effects of mixtures of various levels of pig manure with sandy soil on the growth of tomato (Lycopersicon esculentum Mill) seedlings. Pig manure was mixed with sandy soil at the rates of 0, 25, 50, 75 and 100% respectively on volume/volume basis of the dry materials, the treatments ...

  20. Water flow and pesticide transport in cultivated sandy soils : experimental data on complications

    NARCIS (Netherlands)

    Leistra, M.; Boesten, J.J.T.I.


    The risk of leaching of agricultural pesticides from soil to groundwater and water courses has to be evaluated. Complications in water flow and pesticide transport in humic-sandy and loamy-sandy soil profiles can be expected to increase the risk of leaching. Much of the precipitation water is

  1. Seasonal variation of bivalve larvae on an exposed sandy beach on Kashima-nada: Tips for the sandy beach recruitment process (United States)

    Sawada, Hideki; Saito, Hajime; Adachi, Kumiko; Toyohara, Haruhiko


    Bivalves are often the dominant macrobenthos species in exposed sandy beach environments. However, our understanding of their recruitment processes before post-settlement stages on sandy beaches with highly energetic environments is incomplete. To clarify the characteristics of the free-swimming planktonic stage that affects recruitment efficiency in sandy shore ecosystems, we investigated the temporal (weekly-biweekly) variation of bivalve planktonic larval concentration coupled with oceanographic conditions on an exposed sandy shore on the sea of Kashima-nada, Japan, from summer 2003 to autumn 2005. Larvae were observed throughout the year, but the surge of larval concentration composed of sandy beach and sessile bivalves occurred most prominently in summer, from August to September. The peak concentration of larvae during this season was more than 1000 times higher than in other seasons. The larval concentration was positively correlated with water temperature and northward wind velocity and negatively correlated with each of the nutrient concentrations. On the other hand, chlorophyll a concentration and salinity seemed to have little effect on the larval concentration. Based on this fundamental knowledge, further investigations about planktonic larvae in sandy beaches are needed.

  2. Wind-induced subduction at the South Atlantic subtropical front (United States)

    Calil, Paulo H. R.


    The South Atlantic Subtropical Front, associated with the eastward-flowing South Atlantic Current, separates the colder, nutrient-rich waters of the subpolar gyre from the warmer, nutrient-poor waters of the subtropical gyre. Perturbations to the quasi-geostrophic, eastward flow generate meanders and filaments which induce cross-frontal exchange of water properties. Down-front winds transport denser waters from the South over warm waters from the North, inducing convective instability and subduction. Such processes occur over spatial scales of the order of 1 km and thus require high horizontal spatial resolution. In this modeling study, a high-resolution (4 km) regional grid is embedded in a basin-wide configuration (12 km) of the South Atlantic Ocean in order to test the importance of submesoscale processes in water mass subduction along the subtropical front. Stronger and more numerous eddies obtained in the high-resolution run yield more intense zonal jets along the frontal zone. Such stronger jets are more susceptible to instabilities, frontogenesis, and the generation of submesoscale meanders and filaments with O(1) Rossby number. As a consequence, vertical velocities larger than 100 md 1 are obtained in the high-resolution run, one order of magnitude larger than in the low-resolution run. Wind-driven subduction occurs along the frontal region, associated with negative Ertel potential vorticity in the surface layer. Such processes are not observed in the low-resolution run. A passive tracer experiment shows that waters with density characteristics similar to subtropical mode waters are preferentially subducted along the frontal region. The wind-driven buoyancy flux is shown to be much larger than thermal or haline fluxes during the wintertime, which highlights the importance of the frictional component in extracting PV from the surface ocean and inducing subduction, a process that has been overlooked in subtropical mode water formation in the region.

  3. Coastal Topography--Northeast Atlantic Coast, Post-Hurricane Sandy, 2012: Lidar point-cloud data (LAS) (United States)

    U.S. Geological Survey, Department of the Interior — Binary point-cloud data were produced for a portion of the New York, Delaware, Maryland, Virginia, and North Carolina coastlines, post-Hurricane Sandy (Sandy was an...

  4. Swashed away? Storm impacts on sandy beach macrofaunal communities (United States)

    Harris, Linda; Nel, Ronel; Smale, Malcolm; Schoeman, David


    Storms can have a large impact on sandy shores, with powerful waves eroding large volumes of sand off the beach. Resulting damage to the physical environment has been well-studied but the ecological implications of these natural phenomena are less known. Since climate change predictions suggest an increase in storminess in the near future, understanding these ecological implications is vital if sandy shores are to be proactively managed for resilience. Here, we report on an opportunistic experiment that tests the a priori expectation that storms impact beach macrofaunal communities by modifying natural patterns of beach morphodynamics. Two sites at Sardinia Bay, South Africa, were sampled for macrofauna and physical descriptors following standard sampling methods. This sampling took place five times at three- to four-month intervals between April 2008 and August 2009. The second and last sampling events were undertaken after unusually large storms, the first of which was sufficiently large to transform one site from a sandy beach into a mixed shore for the first time in living memory. A range of univariate (linear mixed-effects models) and multivariate (e.g. non-metric multidimensional scaling, PERMANOVA) methods were employed to describe trends in the time series, and to explore the likelihood of possible explanatory mechanisms. Macrofaunal communities at the dune-backed beach (Site 2) withstood the effects of the first storm but were altered significantly by the second storm. In contrast, macrofauna communities at Site 1, where the supralittoral had been anthropogenically modified so that exchange of sediments with the beach was limited, were strongly affected by the first storm and showed little recovery over the study period. In line with predictions from ecological theory, beach morphodynamics was found to be a strong driver of temporal patterns in the macrofaunal community structure, with the storm events also identified as a significant factor, likely

  5. Visual Odometry for Planetary Exploration Rovers in Sandy Terrains

    Directory of Open Access Journals (Sweden)

    Linhui Li


    Full Text Available Abstract Visual odometry provides planetary exploration rovers with accurate knowledge of their position and orientation, which needs effective feature tracking results, especially in barren sandy terrains. In this paper, a stereovision based odometry algorithm is proposed for a lunar rover, which is composed of corner extraction, feature tracking and motion estimation. First, a morphology based image enhancement method is studied to guarantee enough corners are extracted. Second, a Random Sample Consensus (RANSAC algorithm is proposed to make a robust estimation of the fundamental matrix, which is the basic and critical part of feature matching and tracking. Then, the 6 degrees of freedom rover position and orientation is estimated by the RANSAC algorithm. Finally, experiments are performed in a simulated lunar surface environment using a prototype rover, which have confirmed the feasibility and effectiveness of the proposed method.

  6. Extraction Efficiency of Belonolaimus longicaudatus from Sandy Soil. (United States)

    McSorley, R; Frederick, J J


    Numbers of Belonolaimus longicaudatus extracted from sandy soils (91-92% sand) by sieving and centrifugation were only 40-55% of those extracted by sieving and incubation on a Baermann tray. Residues normally discarded at each step of the sieving plus Baermann tray extraction procedure were examined for nematodes to obtain estimates of extraction efficiencies. For third-stage and fourth-stage juveniles, males, and females, estimates of extraction efficiency ranged from 60 to 65% in one experiment and 73 to 82% in another. Estimated extraction efficiencies for second-stage juveniles were lower (33% in one experiment, 67% in another) due to losses during sieving. When sterilized soil was seeded with known numbers of B. longicaudatus, 60% of second-stage juveniles and 68-76% of other stages were recovered. Most stages of B. longicaudatus could be extracted from these soils by sieving plus Baermann incubation with an efficiency of 60-70%.

  7. Hurricane Sandy: Shared Trauma and Therapist Self-Disclosure. (United States)

    Rao, Nyapati; Mehra, Ashwin


    Hurricane Sandy was one of the most devastating storms to hit the United States in history. The impact of the hurricane included power outages, flooding in the New York City subway system and East River tunnels, disrupted communications, acute shortages of gasoline and food, and a death toll of 113 people. In addition, thousands of residences and businesses in New Jersey and New York were destroyed. This article chronicles the first author's personal and professional experiences as a survivor of the hurricane, more specifically in the dual roles of provider and trauma victim, involving informed self-disclosure with a patient who was also a victim of the hurricane. The general analytic framework of therapy is evaluated in the context of the shared trauma faced by patient and provider alike in the face of the hurricane, leading to important implications for future work on resilience and recovery for both the therapist and patient.

  8. Copper and zinc distribution coefficients for sandy aquifer materials

    DEFF Research Database (Denmark)

    Christensen, Thomas Højlund; Astrup, Thomas; Boddum, J. K.


    Distribution coe�cients (Kd) were measured for copper (Cu) and zinc (Zn) in laboratory batch experiments for 17 sandy aquifer materials at environmentally relevant solute concentrations (Cu: 5±300 mg/l, Zn: 20±3100 mg/l). The Kd values ranged two to three orders of magnitude (Cu: 70±10,800 l/ kg......; Zn: 6±22,800 l/kg) and correlating them to the characteristics of the aquifer material (particle size distribution, organic C content, surface area, pH) revealed good correlation with pH in the range 5.3± 8.9 (Cu: r 2=0.72; Zn: r 2=0.94). Including any other of the measured aquifer characteristics...

  9. Mitigation of Liquefaction in Sandy Soils Using Stone Columns (United States)

    Selcuk, Levent; Kayabalı, Kamil


    Soil liquefaction is one of the leading causes of earthquake-induced damage to structures. Soil improvement methods provide effective solutions to reduce the risk of soil liquefaction. Thus, soil ground treatments are applied using various techniques. However, except for a few ground treatment methods, they generally require a high cost and a lot of time. Especially in order to prevent the risk of soil liquefaction, stone columns conctructed by vibro-systems (vibro-compaction, vibro-replacement) are one of the traditional geotechnical methods. The construction of stone columns not only enhances the ability of clean sand to drain excess pore water during an earthquake, but also increases the relative density of the soil. Thus, this application prevents the development of the excess pore water pressure in sand during earthquakes and keeps the pore pressure ratio below a certain value. This paper presents the stone column methods used against soil liquefaction in detail. At this stage, (a) the performances of the stone columns were investigated in different spacing and diameters of columns during past earthquakes, (b) recent studies about design and field applications of stone columns were presented, and (c) a new design method considering the relative density of soil and the capacity of drenage of columns were explained in sandy soil. Furthermore, with this new method, earthquake performances of the stone columns constructed at different areas were investigated before the 1989 Loma Prieta and the 1994 Northbridge earthquakes, as case histories of field applications, and design charts were compiled for suitable spacing and diameters of stone columns with consideration to the different sandy soil parameters and earhquake conditions. Key Words: Soil improvement, stone column, excess pore water pressure

  10. Glider observations and modeling of sediment transport in Hurricane Sandy (United States)

    Miles, Travis; Seroka, Greg; Kohut, Josh; Schofield, Oscar; Glenn, Scott


    Regional sediment resuspension and transport are examined as Hurricane Sandy made landfall on the Mid-Atlantic Bight (MAB) in October 2012. A Teledyne-Webb Slocum glider, equipped with a Nortek Aquadopp current profiler, was deployed on the continental shelf ahead of the storm, and is used to validate sediment transport routines coupled to the Regional Ocean Modeling System (ROMS). The glider was deployed on 25 October, 5 days before Sandy made landfall in southern New Jersey (NJ) and flew along the 40 m isobath south of the Hudson Shelf Valley. We used optical and acoustic backscatter to compare with two modeled size classes along the glider track, 0.1 and 0.4 mm sand, respectively. Observations and modeling revealed full water column resuspension for both size classes for over 24 h during peak waves and currents, with transport oriented along-shelf toward the southwest. Regional model predictions showed over 3 cm of sediment eroded on the northern portion of the NJ shelf where waves and currents were the highest. As the storm passed and winds reversed from onshore to offshore on the southern portion of the domain waves and subsequently orbital velocities necessary for resuspension were reduced leading to over 3 cm of deposition across the entire shelf, just north of Delaware Bay. This study highlights the utility of gliders as a new asset in support of the development and verification of regional sediment resuspension and transport models, particularly during large tropical and extratropical cyclones when in situ data sets are not readily available.

  11. Quantifying human mobility perturbation and resilience in Hurricane Sandy.

    Directory of Open Access Journals (Sweden)

    Qi Wang

    Full Text Available Human mobility is influenced by environmental change and natural disasters. Researchers have used trip distance distribution, radius of gyration of movements, and individuals' visited locations to understand and capture human mobility patterns and trajectories. However, our knowledge of human movements during natural disasters is limited owing to both a lack of empirical data and the low precision of available data. Here, we studied human mobility using high-resolution movement data from individuals in New York City during and for several days after Hurricane Sandy in 2012. We found the human movements followed truncated power-law distributions during and after Hurricane Sandy, although the β value was noticeably larger during the first 24 hours after the storm struck. Also, we examined two parameters: the center of mass and the radius of gyration of each individual's movements. We found that their values during perturbation states and steady states are highly correlated, suggesting human mobility data obtained in steady states can possibly predict the perturbation state. Our results demonstrate that human movement trajectories experienced significant perturbations during hurricanes, but also exhibited high resilience. We expect the study will stimulate future research on the perturbation and inherent resilience of human mobility under the influence of hurricanes. For example, mobility patterns in coastal urban areas could be examined as hurricanes approach, gain or dissipate in strength, and as the path of the storm changes. Understanding nuances of human mobility under the influence of such disasters will enable more effective evacuation, emergency response planning and development of strategies and policies to reduce fatality, injury, and economic loss.

  12. Quantifying human mobility perturbation and resilience in Hurricane Sandy. (United States)

    Wang, Qi; Taylor, John E


    Human mobility is influenced by environmental change and natural disasters. Researchers have used trip distance distribution, radius of gyration of movements, and individuals' visited locations to understand and capture human mobility patterns and trajectories. However, our knowledge of human movements during natural disasters is limited owing to both a lack of empirical data and the low precision of available data. Here, we studied human mobility using high-resolution movement data from individuals in New York City during and for several days after Hurricane Sandy in 2012. We found the human movements followed truncated power-law distributions during and after Hurricane Sandy, although the β value was noticeably larger during the first 24 hours after the storm struck. Also, we examined two parameters: the center of mass and the radius of gyration of each individual's movements. We found that their values during perturbation states and steady states are highly correlated, suggesting human mobility data obtained in steady states can possibly predict the perturbation state. Our results demonstrate that human movement trajectories experienced significant perturbations during hurricanes, but also exhibited high resilience. We expect the study will stimulate future research on the perturbation and inherent resilience of human mobility under the influence of hurricanes. For example, mobility patterns in coastal urban areas could be examined as hurricanes approach, gain or dissipate in strength, and as the path of the storm changes. Understanding nuances of human mobility under the influence of such disasters will enable more effective evacuation, emergency response planning and development of strategies and policies to reduce fatality, injury, and economic loss.

  13. Posttraumatic Stress Disorder after Hurricane Sandy among Persons Exposed to the 9/11 Disaster. (United States)

    Caramanica, Kimberly; Brackbill, Robert M; Stellman, Steven D; Farfel, Mark R

    Traumatic exposure during a hurricane is associated with adverse mental health conditions post-event. The World Trade Center Health Registry provided a sampling pool for a rapid survey of persons directly affected by Hurricane Sandy in the New York City (NYC) metropolitan area in late October 2012. This study evaluated the relationship between Sandy experiences and Sandy-related posttraumatic stress disorder (PTSD) among individuals previously exposed to the September 11, 2001 (9/11) disaster. A total of 4,558 surveys were completed from April 10-November 7, 2013. After exclusions for missing data, the final sample included 2,214 (53.5%) respondents from FEMA-defined inundation zones and 1,923 (46.5%) from non-inundation zones. Sandy exposures included witnessing terrible events, Sandy-related injury, fearing for own life or safety of others, evacuation, living in a home that was flooded or damaged, property loss, and financial loss. Sandy-related PTSD was defined as a score of ≥44 on a Sandy-specific PTSD Checklist. PTSD prevalence was higher in the inundation zones (11.3%) and lower in the non-inundation zones (4.4%). The highest prevalence of Sandy-related PTSD was among individuals in the inundation zone who sustained an injury (31.2%), reported a history of 9/11-related PTSD (28.8%), or had low social support prior to the event (28.6%). In the inundation zones, significantly elevated adjusted odds of Sandy-related PTSD were observed among persons with a prior history of 9/11-related PTSD, low social support, and those who experienced a greater number of Sandy traumatic events. Sandy-related stress symptoms indicative of PTSD affected a significant proportion of persons who lived in flooded areas of the NYC metropolitan area. Prior 9/11-related PTSD increased the likelihood of Sandy-related PTSD, while social support was protective. Public health preparation for events similar to Sandy should incorporate outreach and linkages to care for persons with prior

  14. Riparian buffer zones as pesticide filters of no-till crops. (United States)

    Aguiar, Terencio R; Bortolozo, F R; Hansel, F A; Rasera, K; Ferreira, M T


    Several studies have pointed to the potential benefits of riparian vegetation as buffer zones for agricultural and industrial pollutants harmful to aquatic ecosystems. However, other studies have called into question its use as an ecological filter, questioning the widths and conditions for which they are effective as a filter. In this work, we have investigated the buffering capacity of the riparian one to retain pesticides in the water-saturated zone, on 27 sites composed by riparian buffer zones with different vegetation structure (woody, shrubs, or grass vegetation) and width (12, 36, and 60 m). Five pesticides were analyzed. The effectiveness of the filtering was largely influenced by the width and vegetation type of the buffer zone. In general, decreasing pesticide removal followed in this order wood > shrubs > grass. The 60 m woody buffer zone was the most effective in the removal of all the pesticides. Only atrazine was detected in this case (0.3 μg L(-1)). Furthermore, a linear correlation (R (2) > 0.97) was observed in their removal for all compounds and buffer zones studied. Thus, preserving the woody vegetation in the riparian zone is important for watershed management and groundwater quality in the no-tillage system in temperate climate.

  15. Biochar Effects on Soil Aggregate Properties Under No-Till Maize

    DEFF Research Database (Denmark)

    Khademalrasoul, Ataalah; Naveed, Muhammad; Heckrath, Goswin Johann


    -over-end shaking, a Yoder-type wet-sieving method, and an unconfined compression test in soil samples collected 7 and 19 months after final biochar application. The highest rates of biochar and swine manure application resulted in the highest aggregate stability and lowest clay dispersibility. Applying both...

  16. Virginia No-Till Fact Sheet Series. Number Six, Nitrogen Fertilizer Sources and Properties


    Alley, Marcus M., 1947-; Thomason, Wade Everett; Woodward, Timothy


    The most commonly available nitrogen fertilizer sources used in Virginia are urea, liquid urea-ammonium nitrate (UAN) solution, and ammonium sulfate. Ammonium nitrate is also available in some areas but its use is low relative to urea and UAN solution. Understanding the properties of these fertilizers enables managers to make better decisions as to the most effective way to use these fertilizers as well as to make economic comparisons.

  17. Effect of 25 years of no till management on soil microbial community structure (United States)

    Archived soil samples from three Colorado dryland sites under wheat-corn-fallow rotations were analyzed by qPCR and pyrosequencing to analyze the effect of 25-years of no tillage management of soil microbial community structure and composition. No tillage significantly increased bacteria abundance...

  18. Starter fertilizer for managing cover crop-based organic rotational no-till corn yields (United States)

    Weed control and N availability limit yield in organic corn production. Grass and legume cover crops are combined in mixtures to provide both weed and fertility management; however, additional fertility may be required to maximize corn yield. Research was conducted at Beltsville, MD, Kinston, NC, an...

  19. Impact of crop rotation and soil amendments on long-term no-tilled soybean yields (United States)

    Continuous cropping systems without cover crops are perceived as unsustainable for long-term yield and soil health. To test this, cropping sequence and cover crop effects on soybean (Glycine max L.) yields were assessed. Main effects were 10 cropping sequences of soybean, corn (Zea mays L.), and co...

  20. Continuous Cropping Systems Reduce Near-Surface Maximum Compaction in No-Till Soils (United States)

    Because of increased concerns over compaction in NT soils, it is important to assess how continuous cropping systems influence risks of soil compaction across a range of soils and NT management systems. We quantified differences in maximum bulk density (BDmax) and critical water content (CWC) by the...

  1. Composition, production, and loss of carbohydrates in subtropical shallow subtidal sandy sediments: Rapid processing and long-term retention revealed by 13C-labeling

    NARCIS (Netherlands)

    Oakes, J.M.; Eyre, B.D.; Middelburg, J.J.; Boschker, H.T.S.


    The composition and production of carbohydrates (mannose, rhamnose, fucose, galactose, glucose, and xylose) and their transfer among sediment compartments (microphytobenthos [MPB], bacteria, and detritus) was investigated through in situ labeling with 13C-bicarbonate. After 60 h, 13C was found in

  2. Shifts of the Subtropical Shelf Front controlled by atmospheric variations (United States)

    Balcerak, Ernie


    In the western South Atlantic, off the coast of South America, a band of cold, fresh, nutrient-rich Sub-Antarctic Shelf Water (SASW) meets warm, salty, nutrient-poor Subtropical Shelf Water (STSW) to form the Subtropical Shelf Front (STSF). This front is the shallow-water expression of the major Brazil-Malvinas Confluence Zone and has moved northward and southward during the Holocene (the past ~12,000 years). Bender et al. reconstruct the latitudinal shifts of the STSF over the past 11,000 calendar-equivalent years using records of oxygen and carbon stable isotope compositions of benthic foraminifera and total organic carbon and calcium carbonate content from a sediment record collected off Uruguay. These measurements serve as proxies for ocean water temperature and nutrient content, which can be used to distinguish the SASW and STSW.

  3. Processing potential of jellies from subtropical loquat cultivars

    Directory of Open Access Journals (Sweden)

    Paula Nogueira CURI


    Full Text Available Abstract To increase the availability to consumers and add more value to loquat (Eriobotrya japonica Lindl., which is a very perishable and seasonal fruit, and in order to identify which cultivars grown in subtropical regions are more suitable for jelly processing, the objective of this study was to evaluate the influence of different loquat cultivars (Fukuhara, Kurisaki, Mizumo, Mizuho and Mizauto grown in subtropical regions of Brazil on the physicochemical characteristics, rheological properties and sensory acceptance of the resulting jelly. Based on sensory acceptance the most suitable loquat cultivars for jelly processing are Kurisaki and Mizuho. In this study it was found that the consumer prefers a more acidic, less sweet, less firm or softer loquat jelly, clearer with a more intense red color.

  4. Inertia-induced accumulation of flotsam in the subtropical gyres (United States)

    Beron-Vera, F. J.; Olascoaga, M. J.; Lumpkin, R.


    Recent surveys of marine plastic debris density have revealed high levels in the center of the subtropical gyres. Earlier studies have argued that the formation of great garbage patches is due to Ekman convergence in such regions. In this work we report a tendency so far overlooked of drogued and undrogued drifters to accumulate distinctly over the subtropical gyres, with undrogued drifters accumulating in the same areas where plastic debris accumulate. We show that the observed accumulation is too fast for Ekman convergence to explain it. We demonstrate that the accumulation is controlled by finite-size and buoyancy (i.e., inertial) effects on undrogued drifter motion subjected to ocean current and wind drags. We infer that the motion of flotsam in general is constrained by similar effects. This is done by using a newly proposed Maxey-Riley equation which models the submerged (surfaced) drifter portion as a sphere of the fractional volume that is submerged (surfaced).

  5. [Fish community structure and its seasonal change in subtidal sandy beach habitat off southern Gouqi Island]. (United States)

    Wang, Zhen-Hua; Wang, Kai; Zhao, Jing; Zhang, Shou-Yu


    To understand the characteristics of fish community structure in sandy beach habitats of island reef water areas, and to evaluate the potential capacity of these habitats in local fish stock maintenance, fishes were monthly collected with multi-mesh trammel nets in 2009 from the subtidal sandy beach habitat off southern Gouqi Island, taking the adjacent rocky reef habitat as the control. alpha and beta species diversity indices, index of relative importance (IRI), relative catch rate, and dominance curve for abundance and biomass (ABC curve) were adopted to compare the fish species composition, diversity, and community pattern between the two habitats, and multivariate statistical analyses such as non-metric multidimensional scaling (nMDS) and cluster were conducted to discuss the fish assemblage patterns. A total of 63 fish species belonging to 11 orders, 38 families, and 56 genera were collected, of which, 46 fish species were appeared in the two habitats. Due to the appearance of more warm water species in sandy bottom, the fishes in subtidal sandy beach habitat showed much higher richness, and the abundance catch rate (ACR) from May to July was higher than that in rocky reef habitat. In most rest months, the ACR in subtidal sandy beach habitat also showed the similar trend. However, the species richness and diversity in spring and summer were significantly lower in subtidal sandy beach habitat than in rocky reef habitat, because of the high species dominance and low evenness in the sandy beach habitat. Japanese tonguefish (Paraplagusia japonica) was the indicator species in the sandy beach habitat, and dominated in early spring, later summer, autumn, and winter when the fishing pressure was not strong. In sandy bottom, a unique community structure was formed and kept in dynamic, due to the nursery use of sandy beach by Japanese anchovy (Engraulis japonicus) from May to July, the gathering of gray mullet (Mugil cephalus) in most months for feeding, and the large

  6. Flowering Control of Tuberose (Polianthes tuberosa L.) in Subtropical Conditions


    Huang, Kuang-Liang; Okubo, Hiroshi; 大久保, 敬


    Effects of temperature and the duration of corm storage on flowering and flower quality of tuberose were examined to establish the most practical method for controlled cut flower production in subtropical conditions. Low temperature storage did not increase cut flower production of the crop at all. Storage at 25℃ increased the loss of water content in the corms, but accelerated sprouting and flowering after planting and improved the quality of cut flowers when compared with low temperature tr...



    Hamilton Luiz Munari Vogel; Mauro Valdir Schumacher; Peter Trüby


    In the above ground biomass of a native forest or plantation are stored large quantities of nutrients, with few studies in the literature, especially concerning micronutrients. The present work aimed to quantify the micronutrients in above ground biomass in a Seasonal Subtropical forest in Itaara-RS, Brazil. For the above ground biomass evaluation, 20 trees of five different diameter classes were felled. The above ground biomass was separated in the following compartments: stem...

  8. Microbiome of Trichodesmium Colonies from the North Pacific Subtropical Gyre


    Mary R. Gradoville; Byron C Crump; Letelier, Ricardo M.; Church, Matthew J; White, Angelicque E.


    Filamentous diazotrophic Cyanobacteria of the genus Trichodesmium, often found in colonial form, provide an important source of new nitrogen to tropical and subtropical marine ecosystems. Colonies are composed of several clades of Trichodesmium in association with a diverse community of bacterial and eukaryotic epibionts. We used high-throughput 16S rRNA and nifH gene sequencing, carbon (C) and dinitrogen (N2) fixation assays, and metagenomics to describe the diversity and functional potentia...

  9. Content Analysis of Select YouTube Postings: Comparisons of Reactions to the Sandy Hook and Aurora Shootings and Hurricane Sandy. (United States)

    Miller, Eric D


    This study details an innovative and methodical content analysis of 2,207 YouTube comments from four different YouTube videos (e.g., breaking news or memorials) related to the 2012 Sandy Hook Elementary School and Aurora theater mass shootings and the catastrophic Hurricane Sandy. As expected, YouTube comments associated with the Sandy Hook shootings (particularly those from a memorial video) were especially likely to feature compassion and grief with lessened hostility. This study highlights differing online contexts by which individuals show grief and related emotions following man-made and natural calamities and how-even in an online environment-powerful situational contexts greatly guide behavior.

  10. EAARL-B Topography-Big Thicket National Preserve: Big Sandy Creek Corridor Unit, Texas, 2014 (United States)

    U.S. Geological Survey, Department of the Interior — A first-surface topography Digital Elevation Model (DEM) mosaic for the Big Sandy Creek Corridor Unit of Big Thicket National Preserve in Texas was produced from...

  11. Self-Reported and FEMA Flood Exposure Assessment after Hurricane Sandy: Association with Mental Health Outcomes

    National Research Council Canada - National Science Library

    Lieberman-Cribbin, Wil; Liu, Bian; Schneider, Samantha; Schwartz, Rebecca; Taioli, Emanuela


    .... Here we assess the concordance in self-reported and Federal Emergency Management (FEMA) flood exposure after Hurricane Sandy and determine the associations between flooding and anxiety, depression, and post-traumatic stress disorder...

  12. 2014 NOAA Ortho-rectified Mosaic of Hurricane Sandy Coastal Impact Area (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains ortho-rectified mosaic tiles at 0.35m GSD created for NOAA Integrated Ocean and Coastal Mapping (IOCM) initiative in Hurricane Sandy coastal...

  13. Impact of Sewage Sludge on Water Movement in Calcareous Sandy Soils

    Directory of Open Access Journals (Sweden)

    A.M. AI-Omran


    Full Text Available The present study was undertaken to investigate the changes in soil physical properties and their effect on water movement under ponded irrigation. Sewage sludge was applied to 10 cm soil depth at rates of 0.25. 75  and 100 Mg-ha-1 to two disturbed soils differing in CaCO3 content. The results showed that cumulative infiltration (1 decreased with an increase in sewage sludge rates. Basic infiltration for slightly calcareous sandy soil was higher than that of moderately calcareous sandy soil, laboratory measurements showed an exponential decrease in saturated hydraulic conductivity and an increase in available water capacity with an increase in sewage sludge rates. For both soils, water diffusivity (D(Q decreased with an increase in sewage sludge rates. The (oral values of slightly calcareous sandy soils were higher than those of moderately calcareous sandy soils.

  14. 2012 USGS EAARL-B Coastal Topography: Post-Sandy, First Surface (NJ) (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — ASCII xyz and binary point-cloud data, as well as a digital elevation model (DEM) of a portion of the New Jersey coastline, pre- and post-Hurricane Sandy (October...

  15. 76 FR 54800 - Sandy Alexander, Clifton, NJ; Notice of Negative Determination on Reconsideration (United States)


    ... Application for Reconsideration for the workers and former workers of Sandy Alexander, Clifton, New Jersey... facts not previously considered; or (3) if in the opinion of the Certifying Officer, a mis...

  16. EAARL-B Topography-Big Thicket National Preserve: Big Sandy Creek Unit, Texas, 2014 (United States)

    U.S. Geological Survey, Department of the Interior — A bare-earth topography digital elevation model (DEM) mosaic for the Big Sandy Creek Unit of Big Thicket National Preserve in Texas, was produced from remotely...

  17. EAARL-B Topography-Big Thicket National Preserve: Big Sandy Creek Unit, Texas, 2014 (United States)

    U.S. Geological Survey, Department of the Interior — A first-surface topography digital elevation model (DEM) mosaic for the Big Sandy Creek Unit of Big Thicket National Preserve in Texas, was produced from remotely...

  18. EAARL-B Topography-Big Thicket National Preserve: Big Sandy Creek Corridor Unit, Texas, 2014 (United States)

    U.S. Geological Survey, Department of the Interior — A bare-earth topography Digital Elevation Model (DEM) mosaic for the Big Sandy Creek Corridor Unit of Big Thicket National Preserve in Texas was produced from...

  19. 2012-2013 Post-Hurricane Sandy EAARL-B Submerged Topography - Barnegat Bay, New Jersey (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Binary point-cloud data for part of Barnegat Bay, New Jersey, post-Hurricane Sandy (October 2012 hurricane), were produced from remotely sensed, geographically...

  20. 2014 U.S. Geological Survey CMGP LiDAR: Post Sandy (New Jersey) (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — TASK NAME: USGS New Jersey CMGP Sandy Lidar 0.7 Meter NPS LIDAR lidar Data Acquisition and Processing Production Task USGS Contract No. G10PC00057 Task Order No....

  1. Assessing potential of biochar for increasing water‐holding capacity of sandy soils

    National Research Council Canada - National Science Library

    Basso, Andres S; Miguez, Fernando E; Laird, David A; Horton, Robert; Westgate, Mark


    Increasing the water‐holding capacity of sandy soils will help improve efficiency of water use in agricultural production, and may be critical for providing enough energy and food for an increasing global population...

  2. Phosphorus fractions in sandy soils of vineyards in southern Brazil

    Directory of Open Access Journals (Sweden)

    Djalma Eugênio Schmitt


    Full Text Available Phosphorus (P applications to vineyards can cause P accumulation in the soil and maximize pollution risks. This study was carried out to quantify the accumulation of P fractions in sandy soils of vineyards in southern Brazil. Soil samples (layers 0-5, 6-10 and 11-20 cm were collected from a native grassland area and two vineyards, after 14 years (vineyard 1 and 30 years (vineyard 2 of cultivation, in Santana do Livramento, southern Brazil, and subjected to chemical fractionation of P. Phosphorus application, especially to the 30-year-old vineyard 2, increased the inorganic P content down to a depth of 20 cm, mainly in the labile fractions extracted by anion-exchange resin and NaHCO3, in the moderately labile fraction extracted by 0.1 and 0.5 mol L-1 NaOH, and in the non-labile fraction extracted by 1 mol L-1 HCl, indicating the possibility of water eutrophication. Phosphorus application and grapevine cultivation time increased the P content in the organic fraction extracted by NaHCO3 from the 0-5 cm layer, and especially in the moderately labile fraction extracted by 0.1 mol L-1 NaOH, down to a depth of 20 cm.

  3. Heat transport dynamics at a sandy intertidal zone (United States)

    Befus, Kevin M.; Cardenas, M. Bayani; Erler, Dirk V.; Santos, Isaac R.; Eyre, Bradley D.


    Intertidal zones are spatially complex and temporally dynamic environments. Coastal groundwater discharge, including submarine groundwater discharge, may provide stabilizing conditions for intertidal zone permeable sediments. In this study, we integrated detailed time series temperature observations, porewater pressure measurements, and two-dimensional electrical resistivity tomography profiles to understand the coupled hydraulic-thermal regime of a tropical sandy intertidal zone in a fringing coral reef lagoon (Rarotonga, Cook Islands). We found three heating patterns across the 15 m study transect over tidal and diel periods: (1) a highly variable thermal regime dominated by swash infiltration and changes in saturation state in the upper foreshore with net heat import into the sediment, (2) a groundwater-supported underground stable, cool region just seaward of the intertidal slope break also importing heat into the subsurface, and (3) a zone of seawater recirculation that sustained consistently warm subsurface temperatures that exported heat across the sediment-water interface. Simple calculations suggested thermal conduction as the main heat transport mechanism for the shallow intertidal sediment, but deeper and/or multidimensional groundwater flow was required to explain temperature patterns beyond 20 cm depth. Temperature differences between the distinct hydrodynamic zones of the foreshore site resulted in significant thermal gradients that persisted beyond tidal and diel periods. The thermal buffering of intertidal zones by coastal groundwater systems, both at surface seeps and in the shallow subsurface, can be responsible for thermal refugia for some coastal organisms and hotspots for biogeochemical reactions.

  4. Evaluation of the Intel Sandy Bridge-EP server processor

    CERN Document Server

    Jarp, S; Leduc, J; Nowak, A; CERN. Geneva. IT Department


    In this paper we report on a set of benchmark results recently obtained by CERN openlab when comparing an 8-core “Sandy Bridge-EP” processor with Intel’s previous microarchitecture, the “Westmere-EP”. The Intel marketing names for these processors are “Xeon E5-2600 processor series” and “Xeon 5600 processor series”, respectively. Both processors are produced in a 32nm process, and both platforms are dual-socket servers. Multiple benchmarks were used to get a good understanding of the performance of the new processor. We used both industry-standard benchmarks, such as SPEC2006, and specific High Energy Physics benchmarks, representing both simulation of physics detectors and data analysis of physics events. Before summarizing the results we must stress the fact that benchmarking of modern processors is a very complex affair. One has to control (at least) the following features: processor frequency, overclocking via Turbo mode, the number of physical cores in use, the use of logical cores ...

  5. Sensible Heat Flux Related to Variations in Atmospheric Turbulence Kinetic Energy on a Sandy Beach (United States)



  6. Assessment of the Impact of Super Storm Sandy on Coral Reefs of Guantanamo Bay, Cuba (United States)


    TECHNICAL REPORT 2065 January 2015 Assessment of the Impact of Super Storm Sandy on Coral Reefs of Guantánamo Bay , Cuba...TECHNICAL REPORT 2065 January 2015 Assessment of the Impact of Super Storm Sandy on Coral Reefs of Guantánamo Bay , Cuba Cheryl...thank the staff of U.S. Navy Diving Locker, Guantánamo Bay , Cuba. Without their support, diving and boat operations would not have been accomplished

  7. Investigation of superstorm Sandy 2012 in a multi-disciplinary approach (United States)

    Kunz, M.; Mühr, B.; Kunz-Plapp, T.; Daniell, J. E.; Khazai, B.; Wenzel, F.; Vannieuwenhuyse, M.; Comes, T.; Elmer, F.; Schröter, K.; Fohringer, J.; Münzberg, T.; Lucas, C.; Zschau, J.


    At the end of October 2012, Hurricane Sandy moved from the Caribbean Sea into the Atlantic Ocean and entered the United States not far from New York. Along its track, Sandy caused more than 200 fatalities and severe losses in Jamaica, The Bahamas, Haiti, Cuba, and the US. This paper demonstrates the capability and potential for near-real-time analysis of catastrophes. It is shown that the impact of Sandy was driven by the superposition of different extremes (high wind speeds, storm surge, heavy precipitation) and by cascading effects. In particular the interaction between Sandy and an extra-tropical weather system created a huge storm that affected large areas in the US. It is examined how Sandy compares to historic hurricane events, both from a hydro-meteorological and impact perspective. The distribution of losses to different sectors of the economy is calculated with simple input-output models as well as government estimates. Direct economic losses are estimated about USD 4.2 billion in the Caribbean and between USD 78 and 97 billion in the US. Indirect economic losses from power outages is estimated in the order of USD 16.3 billion. Modelling sector-specific dependencies quantifies total business interruption losses between USD 10.8 and 15.5 billion. Thus, seven years after the record impact of Hurricane Katrina in 2005, Hurricane Sandy is the second costliest hurricane in the history of the United States.

  8. Hurricane Sandy (New Jersey): Mortality Rates in the Following Month and Quarter. (United States)

    Kim, Soyeon; Kulkarni, Prathit A; Rajan, Mangala; Thomas, Pauline; Tsai, Stella; Tan, Christina; Davidow, Amy


    To describe changes in mortality after Hurricane Sandy made landfall in New Jersey on October 29, 2012. We used electronic death records to describe changes in all-cause and cause-specific mortality overall, in persons aged 76 years or older, and by 3 Sandy impact levels for the month and quarter following Hurricane Sandy compared with the same periods in earlier years adjusted for trends. All-cause mortality increased 6% (95% confidence interval [CI] = 2%, 11%) for the month, 5%, 8%, and 12% by increasing Sandy impact level; and 7% (95% CI = 5%, 10%) for the quarter, 5%, 8%, and 15% by increasing Sandy impact level. In elderly persons, all-cause mortality rates increased 10% (95% CI = 5%, 15%) and 13% (95% CI = 10%, 16%) in the month and quarter, respectively. Deaths that were cardiovascular disease-related increased by 6% in both periods, noninfectious respiratory disease-related by 24% in the quarter, infection-related by 20% in the quarter, and unintentional injury-related by 23% in the month. Mortality increased, heterogeneous by cause, for both periods after Hurricane Sandy, particularly in communities more severely affected and in the elderly, who may benefit from supportive services.

  9. Investigation of superstorm Sandy 2012 in a multi-disciplinary approach

    Directory of Open Access Journals (Sweden)

    M. Kunz


    Full Text Available At the end of October 2012, Hurricane Sandy moved from the Caribbean Sea into the Atlantic Ocean and entered the United States not far from New York. Along its track, Sandy caused more than 200 fatalities and severe losses in Jamaica, The Bahamas, Haiti, Cuba, and the US. This paper demonstrates the capability and potential for near-real-time analysis of catastrophes. It is shown that the impact of Sandy was driven by the superposition of different extremes (high wind speeds, storm surge, heavy precipitation and by cascading effects. In particular the interaction between Sandy and an extra-tropical weather system created a huge storm that affected large areas in the US. It is examined how Sandy compares to historic hurricane events, both from a hydro-meteorological and impact perspective. The distribution of losses to different sectors of the economy is calculated with simple input-output models as well as government estimates. Direct economic losses are estimated about USD 4.2 billion in the Caribbean and between USD 78 and 97 billion in the US. Indirect economic losses from power outages is estimated in the order of USD 16.3 billion. Modelling sector-specific dependencies quantifies total business interruption losses between USD 10.8 and 15.5 billion. Thus, seven years after the record impact of Hurricane Katrina in 2005, Hurricane Sandy is the second costliest hurricane in the history of the United States.

  10. Effects of Freshwater Discharge in Sandy Beach Populations: The Mole Crab Emerita brasiliensis in Uruguay (United States)

    Lercari, D.; Defeo, O.


    Sandy beaches are ecosystems which are heavily affected by human activities. An example of this is freshwater discharges, which are known to change salinity, temperature and nutrient regimes and degrade nearshore environments. However, the effects of this kind of disturbance on sandy beach fauna have been little studied. This paper reports the spatial effects of a man-made freshwater canal discharge on the population structure, abundance and reproductive characteristics of the sandy beach mole crab Emerita brasiliensis. Along the 22 km of sandy beach sampled, the mole crab showed a marked longshore variability in population structure and abundance. Abundance of different population components (juveniles, males, females and ovigerous females) significantly decreased towards the canal. Population structure by sex and size, individual weight, fecundity and female maturity patterns at size also displayed a non-linear response to the distance from the freshwater discharge. Only the size structure of males did not follow this pattern. For males, spatial heterogeneity enhanced the detection of density-dependence at less disturbed sites. The authors conclude that artificial freshwater discharges could significantly influence the distribution, abundance and life-history traits of the biota of sandy beaches, and that further study of these ecosystems should include human activities as important factors affecting spatial and temporal trends. The need to consider different spatial and temporal scales in order to detect the effect of anthropogenically-driven impacts in sandy beach populations is stressed.

  11. Perfluoroalkylated substances in the global tropical and subtropical surface oceans. (United States)

    González-Gaya, Belén; Dachs, Jordi; Roscales, Jose L; Caballero, Gemma; Jiménez, Begoña


    In this study, perfluoroalkylated substances (PFASs) were analyzed in 92 surface seawater samples taken during the Malaspina 2010 expedition which covered all the tropical and subtropical Atlantic, Pacific and Indian oceans. Nine ionic PFASs including C6-C10 perfluoroalkyl carboxylic acids (PFCAs), C4 and C6-C8 perfluoroalkyl sulfonic acids (PFSAs) and two neutral precursors perfluoroalkyl sulfonamides (PFASAs), were identified and quantified. The Atlantic Ocean presented the broader range in concentrations of total PFASs (131-10900 pg/L, median 645 pg/L, n = 45) compared to the other oceanic basins, probably due to a better spatial coverage. Total concentrations in the Pacific ranged from 344 to 2500 pg/L (median = 527 pg/L, n = 27) and in the Indian Ocean from 176 to 1976 pg/L (median = 329, n = 18). Perfluorooctanesulfonic acid (PFOS) was the most abundant compound, accounting for 33% of the total PFASs globally, followed by perfluorodecanoic acid (PFDA, 22%) and perfluorohexanoic acid (PFHxA, 12%), being the rest of the individual congeners under 10% of total PFASs, even for perfluorooctane carboxylic acid (PFOA, 6%). PFASAs accounted for less than 1% of the total PFASs concentration. This study reports the ubiquitous occurrence of PFCAs, PFSAs, and PFASAs in the global ocean, being the first attempt, to our knowledge, to show a comprehensive assessment in surface water samples collected in a single oceanic expedition covering tropical and subtropical oceans. The potential factors affecting their distribution patterns were assessed including the distance to coastal regions, oceanic subtropical gyres, currents and biogeochemical processes. Field evidence of biogeochemical controls on the occurrence of PFASs was tentatively assessed considering environmental variables (solar radiation, temperature, chlorophyll a concentrations among others), and these showed significant correlations with some PFASs, but explaining small to moderate percentages of variability

  12. Phosphorus leaching from biosolids-amended sandy soils. (United States)

    Elliott, H A; O'Connor, G A; Brinton, S


    Increasing emphasis on phosphorus (P)-based nutrient management underscores the need to understand P behavior in soils amended with biosolids and manures. Laboratory and greenhouse column studies characterized P forms and leachability of eight biosolids products, chicken manure (CM), and commercial fertilizer (triple superphosphate, TSP). Bahiagrass (Paspalum notatum Flugge) was grown for 4 mo on two acid, P-deficient Florida sands, representing both moderate (Candler series: hyperthermic, uncoated Typic Quartzipsamments) and very low (Immokalee series: sandy, siliceous, hyperthermic Arenic Alaquods) P-sorbing capacities. Amendments were applied at 56 and 224 kg P(T) ha(-1), simulating P-based and N-based nutrient loadings, respectively. Column leachate P was dominantly inorganic and lower for biosolids P sources than TSP. For Candler soil, only TSP at the high P rate exhibited P leaching statistically greater (alpha = 0.05) than control (soil-only) columns. For the high P rate and low P-sorbing Immokalee soil, TSP and CM leached 21 and 3.0% of applied P, respectively. Leachate P for six biosolids was biological P removal process, exhibited significantly greater leachate P in both cake and pelletized forms (11 and 2.5% of applied P, respectively) than other biosolids. Biosolids P leaching was correlated to the phosphorus saturation index (PSI = [Pox]/[Al(ox) + Fe(ox)]) based on oxalate extraction of the pre-applied biosolids. For hiosolids with PSI < or = approximately 1.1, no appreciable leaching occurred. Only Largo cake (PSI = 1.4) and pellets (PSI = 1.3) exhibited P leaching losses statistically greater than controls. The biosolids PSI appears useful for identifying biosolids with potential to enrich drainage P when applied to low P-sorbing soils.

  13. Turbulent vertical diffusivity in the sub-tropical stratosphere

    Directory of Open Access Journals (Sweden)

    I. Pisso


    Full Text Available Vertical (cross-isentropic mixing is produced by small-scale turbulent processes which are still poorly understood and paramaterized in numerical models. In this work we provide estimates of local equivalent diffusion in the lower stratosphere by comparing balloon borne high-resolution measurements of chemical tracers with reconstructed mixing ratio from large ensembles of random Lagrangian backward trajectories using European Centre for Medium-range Weather Forecasts analysed winds and a chemistry-transport model (REPROBUS. We focus on a case study in subtropical latitudes using data from HIBISCUS campaign. An upper bound on the vertical diffusivity is found in this case study to be of the order of 0.5 m2 s−1 in the subtropical region, which is larger than the estimates at higher latitudes. The relation between diffusion and dispersion is studied by estimating Lyapunov exponents and studying their variation according to the presence of active dynamical structures.

  14. Phytoplankton Growth and Microzooplankton Grazing in the Subtropical Northeast Atlantic (United States)

    Cáceres, Carlos; Taboada, Fernando González; Höfer, Juan; Anadón, Ricardo


    Dilution experiments were performed to estimate phytoplankton growth and microzooplankton grazing rates during two Lagrangian surveys in inner and eastern locations of the Eastern North Atlantic Subtropical Gyre province (NAST-E). Our design included two phytoplankton size fractions (0.2–5 µm and >5 µm) and five depths, allowing us to characterize differences in growth and grazing rates between size fractions and depths, as well as to estimate vertically integrated measurements. Phytoplankton growth rates were high (0.11–1.60 d−1), especially in the case of the large fraction. Grazing rates were also high (0.15–1.29 d−1), suggesting high turnover rates within the phytoplankton community. The integrated balances between phytoplankton growth and grazing losses were close to zero, although deviations were detected at several depths. Also, O2 supersaturation was observed up to 110 m depth during both Lagrangian surveys. These results add up to increased evidence indicating an autotrophic metabolic balance in oceanic subtropical gyres. PMID:23935946

  15. Phytoplankton growth and microzooplankton grazing in the subtropical Northeast Atlantic.

    Directory of Open Access Journals (Sweden)

    Carlos Cáceres

    Full Text Available Dilution experiments were performed to estimate phytoplankton growth and microzooplankton grazing rates during two Lagrangian surveys in inner and eastern locations of the Eastern North Atlantic Subtropical Gyre province (NAST-E. Our design included two phytoplankton size fractions (0.2-5 µm and >5 µm and five depths, allowing us to characterize differences in growth and grazing rates between size fractions and depths, as well as to estimate vertically integrated measurements. Phytoplankton growth rates were high (0.11-1.60 d(-1, especially in the case of the large fraction. Grazing rates were also high (0.15-1.29 d(-1, suggesting high turnover rates within the phytoplankton community. The integrated balances between phytoplankton growth and grazing losses were close to zero, although deviations were detected at several depths. Also, O2 supersaturation was observed up to 110 m depth during both Lagrangian surveys. These results add up to increased evidence indicating an autotrophic metabolic balance in oceanic subtropical gyres.

  16. Hydrological implications of desertification: Degradation of South African semi-arid subtropical thicket

    NARCIS (Netherlands)

    Luijk, van G.; Cowling, R.M.; Riksen, M.J.P.M.; Glenday, J.


    Almost half of the 16,942 km2 of South Africa's subtropical thicket with a substantial Portulacaria afra (spekboom) component has been heavily degraded by domestic herbivores. The subtropical thicket biome is a drought-prone and water-stressed area, and many of the region's watersheds comprise of

  17. Vulnerable, But Why? Post-Traumatic Stress Symptoms in Older Adults Exposed to Hurricane Sandy. (United States)

    Heid, Allison R; Christman, Zachary; Pruchno, Rachel; Cartwright, Francine P; Wilson-Genderson, Maureen


    Drawing on pre-disaster, peri-disaster, and post-disaster data, this study examined factors associated with the development of post-traumatic stress disorder (PTSD) symptoms in older adults exposed to Hurricane Sandy. We used a sample of older participants matched by gender, exposure, and geographic region (N=88, mean age=59.83 years) in which one group reported clinically significant levels of PTSD symptoms and the other did not. We conducted t-tests, chi-square tests, and exact logistic regressions to examine differences in pre-disaster characteristics and peri-disaster experiences. Older adults who experienced PTSD symptoms reported lower levels of income, positive affect, subjective health, and social support and were less likely to be working 4 to 6 years before Hurricane Sandy than were people not experiencing PTSD symptoms. Those developing PTSD symptoms reported more depressive symptoms, negative affect, functional disability, chronic health conditions, and pain before Sandy and greater distress and feelings of danger during Hurricane Sandy. Exact logistic regression revealed independent effects of preexisting chronic health conditions and feelings of distress during Hurricane Sandy in predicting PTSD group status. Our findings indicated that because vulnerable adults can be identified before disaster strikes, the opportunity to mitigate disaster-related PTSD exists through identification and resource programs that target population subgroups. (Disaster Med Public Health Preparedness. 2016;10:362-370).

  18. What Would Happen to Superstorm Sandy Under the Influence of a Substantially Warmer Atlantic Ocean? (United States)

    Lau, William K. M.; Shi, J. J.; Tao, W. K.; Kim, K. M.


    Based on ensemble numerical simulations, we find that possible responses of Sandy-like superstorms under the influence of a substantially warmer Atlantic Ocean bifurcate into two groups. In the first group, storms are similar to present-day Sandy from genesis to extratropical transition, except they are much stronger, with peak Power Destructive Index (PDI) increased by 50-80%, heavy rain by 30-50%, and maximum storm size (MSS) approximately doubled. In the second group, storms amplify substantially over the interior of the Atlantic warm pool, with peak PDI increased by 100-160%, heavy rain by 70-180%, and MSS more than tripled compared to present-day Superstorm Sandy. These storms when exiting the warm pool, recurve northeastward out to sea, subsequently interact with the developing midlatitude storm by mutual counterclockwise rotation around each other and eventually amplify into a severe Northeastern coastal storm, making landfall over the extreme northeastern regions from Maine to Nova Scotia.

  19. Analysis of storm-tide impacts from Hurricane Sandy in New York (United States)

    Schubert, Christopher E.; Busciolano, Ronald J.; Hearn, Paul P.; Rahav, Ami N.; Behrens, Riley; Finkelstein, Jason S.; Monti, Jack; Simonson, Amy E.


    The hybrid cyclone-nor’easter known as Hurricane Sandy affected the mid-Atlantic and northeastern United States during October 28-30, 2012, causing extensive coastal flooding. Prior to storm landfall, the U.S. Geological Survey (USGS) deployed a temporary monitoring network from Virginia to Maine to record the storm tide and coastal flooding generated by Hurricane Sandy. This sensor network augmented USGS and National Oceanic and Atmospheric Administration (NOAA) networks of permanent monitoring sites that also documented storm surge. Continuous data from these networks were supplemented by an extensive post-storm high-water-mark (HWM) flagging and surveying campaign. The sensor deployment and HWM campaign were conducted under a directed mission assignment by the Federal Emergency Management Agency (FEMA). The need for hydrologic interpretation of monitoring data to assist in flood-damage analysis and future flood mitigation prompted the current analysis of Hurricane Sandy by the USGS under this FEMA mission assignment.

  20. Effects of sodium polyacrylate on water retention and infiltration capacity of a sandy soil. (United States)

    Zhuang, Wenhua; Li, Longguo; Liu, Chao


    Based on the laboratory study, the effects of sodium polyacrylate (SP) was investigated at 5 rates of 0, 0.08, 0.2, 0.5, and 1%, on water retention, saturated hydraulic conductivity(Ks), infiltration characteristic and water distribution profiles of a sandy soil. The results showed that water retention and available water capacity effectively increased with increasing SP rate. The Ks and the rate of wetting front advance and infiltration under certain pond infiltration was significantly reduced by increasing SP rate, which effectively reduced water in a sandy soil leaking to a deeper layer under the plough layer. The effect of SP on water distribution was obviously to the up layer and very little to the following deeper layers. Considering both the effects on water retention and infiltration capacity, it is suggested that SP be used to the sandy soil at concentrations ranging from 0.2 to 0.5%.

  1. Superstorm Sandy: How the New York University Psychiatry Residency Training Program Weathered the Storm. (United States)

    Capasso, Rebecca; Adler, Laura


    The teaching hospitals of the New York University psychiatry residency program were evacuated and then closed for a minimum of 3 months in the aftermath of Superstorm Sandy. Faculty and residents were deployed to alternate clinical sites. The authors examine the consequences of Superstorm Sandy and its implications for the New York University psychiatry residency training program. A survey was administered to faculty and residents. The authors tabulated 98 surveys, for which 24 % of faculty and 84 % of residents responded. Among respondents, 61 % believed that being involved in the evacuation of the hospitals was a positive experience. During deployment, most (85 %) found being placed with peers and supervisors to be beneficial, but there were significant disruptions. Despite facing multiple challenges including closed facilities, deployment to nonaffiliated hospitals, and exhausted personal resources, the training program continued to provide accredited clinical experiences, a core curriculum, and supervision for psychiatry residents during and after Superstorm Sandy.

  2. Nitrate source apportionment in a subtropical watershed using Bayesian model

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Liping; Han, Jiangpei; Xue, Jianlong; Zeng, Lingzao [College of Environmental and Natural Resource Sciences, Zhejiang Provincial Key Laboratory of Subtropical Soil and Plant Nutrition, Zhejiang University, Hangzhou, 310058 (China); Shi, Jiachun, E-mail: [College of Environmental and Natural Resource Sciences, Zhejiang Provincial Key Laboratory of Subtropical Soil and Plant Nutrition, Zhejiang University, Hangzhou, 310058 (China); Wu, Laosheng, E-mail: [College of Environmental and Natural Resource Sciences, Zhejiang Provincial Key Laboratory of Subtropical Soil and Plant Nutrition, Zhejiang University, Hangzhou, 310058 (China); Jiang, Yonghai [State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, 100012 (China)


    Nitrate (NO{sub 3}{sup −}) pollution in aquatic system is a worldwide problem. The temporal distribution pattern and sources of nitrate are of great concern for water quality. The nitrogen (N) cycling processes in a subtropical watershed located in Changxing County, Zhejiang Province, China were greatly influenced by the temporal variations of precipitation and temperature during the study period (September 2011 to July 2012). The highest NO{sub 3}{sup −} concentration in water was in May (wet season, mean ± SD = 17.45 ± 9.50 mg L{sup −1}) and the lowest concentration occurred in December (dry season, mean ± SD = 10.54 ± 6.28 mg L{sup −1}). Nevertheless, no water sample in the study area exceeds the WHO drinking water limit of 50 mg L{sup −1} NO{sub 3}{sup −}. Four sources of NO{sub 3}{sup −} (atmospheric deposition, AD; soil N, SN; synthetic fertilizer, SF; manure and sewage, M and S) were identified using both hydrochemical characteristics [Cl{sup −}, NO{sub 3}{sup −}, HCO{sub 3}{sup −}, SO{sub 4}{sup 2−}, Ca{sup 2+}, K{sup +}, Mg{sup 2+}, Na{sup +}, dissolved oxygen (DO)] and dual isotope approach (δ{sup 15}N–NO{sub 3}{sup −} and δ{sup 18}O–NO{sub 3}{sup −}). Both chemical and isotopic characteristics indicated that denitrification was not the main N cycling process in the study area. Using a Bayesian model (stable isotope analysis in R, SIAR), the contribution of each source was apportioned. Source apportionment results showed that source contributions differed significantly between the dry and wet season, AD and M and S contributed more in December than in May. In contrast, SN and SF contributed more NO{sub 3}{sup −} to water in May than that in December. M and S and SF were the major contributors in December and May, respectively. Moreover, the shortcomings and uncertainties of SIAR were discussed to provide implications for future works. With the assessment of temporal variation and sources of NO{sub 3}{sup −}, better

  3. Numerical modeling of salt marsh morphological change induced by Hurricane Sandy (United States)

    Hu, Kelin; Chen, Qin; Wang, Hongqing; Hartig, Ellen K.; Orton, Philip M.


    The salt marshes of Jamaica Bay serve as a recreational outlet for New York City residents, mitigate wave impacts during coastal storms, and provide habitat for critical wildlife species. Hurricanes have been recognized as one of the critical drivers of coastal wetland morphology due to their effects on hydrodynamics and sediment transport, deposition, and erosion processes. In this study, the Delft3D modeling suite was utilized to examine the effects of Hurricane Sandy (2012) on salt marsh morphology in Jamaica Bay. Observed marsh elevation change and accretion from rod Surface Elevation Tables and feldspar Marker Horizons (SET-MH) and hydrodynamic measurements during Hurricane Sandy were used to calibrate and validate the wind-waves-surge-sediment transport-morphology coupled model. The model results agreed well with in situ field measurements. The validated model was then used to detect salt marsh morphological change due to Sandy across Jamaica Bay. Model results indicate that the island-wide morphological changes in the bay's salt marshes due to Sandy were in the range of −30 mm (erosion) to +15 mm (deposition), and spatially complex and heterogeneous. The storm generated paired deposition and erosion patches at local scales. Salt marshes inside the west section of the bay showed erosion overall while marshes inside the east section showed deposition from Sandy. The net sediment amount that Sandy brought into the bay is only about 1% of the total amount of reworked sediment within the bay during the storm. Numerical experiments show that waves and vegetation played a critical role in sediment transport and associated wetland morphological change in Jamaica Bay. Furthermore, without the protection of vegetation, the marsh islands of Jamaica Bay would experience both more erosion and less accretion in coastal storms.

  4. Propagation of Love waves in a void medium over a sandy half space under gravity (United States)

    Patra, Pulak; Gupta, Asit Kumar; Kundu, Santimoy


    The present study investigates the propagation of Love wave in a void layer resting over a sandy half space under the effect of gravitational force. The equations of motion have been gathered separately for different layers, and the boundary conditions have been introduced for two different layers at their interface. The mathematical analysis of the problem has been dealt with the help of Whittaker's function by expanding it asymptotically up to linear terms. The study reveals that in such a situation there exist two different wave fronts for the two above-mentioned layers: one is for the effects of gravity and sandy parameters, whereas other is for the effect of void parameter.

  5. Propagation of Rayleigh waves in anisotropic layer overlying a semi-infinite sandy medium

    Directory of Open Access Journals (Sweden)

    P.C. Pal


    Full Text Available The present investigation deals with the propagation of Rayleigh waves in anisotropic layer overlying a sandy medium. Anisotropic material is in the nature of most general case i.e. of triclinic crystal and sandy medium is of alluvial soil type. The solutions for layer and half-space are obtained analytically. The displacement components in x and z directions are obtained for both the media. The dispersion relation is obtained subjected to certain boundary conditions. The special cases are considered. The numerical results are presented in the form of wave number and phase velocity (k − c analytical curves.

  6. Soil organic matter of a sandy soil influenced by agronomy and climate


    ELLMER, Frank


    Long term field experiments are being conducted at Humboldt University of Berlin (Germany) to obtain information regarding sustainable management of arable land with sandy soils. In Thyrow, a location in the south of Berlin with silty and sandy soil (85 % sand, 12 % silt, 3 % clay, 0.5 % Corg, pH 5.5) several experiments have been carried out since 1937. They include the study of the long-term effects of the agronomic factors of: crop rotation; organic fertilization; mineral ferti...

  7. Inertia-induced accumulation of flotsam in the subtropical gyres

    CERN Document Server

    Beron-Vera, Francisco J; Lumpkin, Rick


    Recent surveys of marine plastic debris density have revealed high levels in the center of the subtropical gyres. Earlier studies have argued that the formation of great garbage patches is due to Ekman convergence in such regions. In this work we report, for the first time, a tendency of satellite-tracked surface drifting buoys which have lost their sea anchors (drogues) to accumulate in the same regions of the world oceans that plastic debris accumulate. We show that the observed accumulation is too fast for Ekman convergence to explain it. We demonstrate that the accumulation is controlled by finite-size and buoyancy (i.e., inertial) effects on undrogued drifter motion subjected to ocean current and wind drags. We infer that the motion of flotsam in general is constrained by similar effects.

  8. Metal contamination of vineyard soils in wet subtropics (southern Brazil). (United States)

    Mirlean, Nicolai; Roisenberg, Ari; Chies, Jaqueline O


    The vine-growing areas in Brazil are the dampest in the world. Copper maximum value registered in this study was as much as 3200 mg kg(-1), which is several times higher than reported for vineyard soils in temperate climates. Other pesticide-derived metals accumulate in the topsoil layer, surpassing in the old vineyards the background value several times for Zn, Pb, Cr and Cd. Copper is transported to deeper soils' horizons and can potentially contaminate groundwater. The soils from basaltic volcanic rocks reveal the highest values of Cu extracted with CaCl(2), demonstrating a high capacity of copper transference into plants. When evaluating the risks of copper's toxic effects in subtropics, the soils from rhyolitic volcanic rocks are more worrisome, as the Cu extracted with ammonium acetate 1M surpasses the toxic threshold as much as 4-6 times.


    Directory of Open Access Journals (Sweden)

    Jose de Jesus Navar Chaidez


    Full Text Available This research work aimed at the study of the root allometry in subtropical Tamaulipan thornscrub and pine forest communities of Nuevo Leon, Mexico. By excavating each individual root of each of 20 trees per plant community, we developed root allometric equations for biomass, volume, total length and diameter. Covariance analysis, ancova, was employed to determine the statistical difference of these parameters between plant communities. Results indicate that pine plant trees have larger root volumes, longer root systems and higher root basic densities than trees of Tamaulipan thornscrub forests. This piece of information is key to estimate root biomass, volume, total length and diameter of roots of trees of these plant communities at the stand scale; important environmental information.Key words: Power equations, ancova, root biomass, volume, length and diameter.

  10. Marine debris collects within the North Pacific Subtropical Convergence Zone. (United States)

    Pichel, William G; Churnside, James H; Veenstra, Timothy S; Foley, David G; Friedman, Karen S; Brainard, Russell E; Nicoll, Jeremy B; Zheng, Quanan; Clemente-Colón, Pablo


    Floating marine debris, particularly derelict fishing gear, is a hazard to fish, marine mammals, turtles, sea birds, coral reefs, and even human activities. To ameliorate the economic and environmental impact of marine debris, we need to efficiently locate and retrieve dangerous debris at sea. Guided by satellite-derived information, we made four flights north of Hawaii in March and April 2005. During these aerial surveys, we observed over 1800 individual pieces of debris, including 122 derelict fishing nets. The largest debris concentrations were found just north of the North Pacific Transition Zone Chlorophyll Front (TZCF) within the North Pacific Subtropical Convergence Zone (STCZ). Debris densities were significantly correlated with sea-surface temperature (SST), chlorophyll-a concentration (Chla), and the gradient of Chla. A Debris Estimated Likelihood Index (DELI) was developed to predict where high concentrations of debris would be most likely in the North Pacific during spring and early summer.

  11. Biodiversity promotes tree growth during succession in subtropical forest.

    Directory of Open Access Journals (Sweden)

    Martin Barrufol

    Full Text Available Losses of plant species diversity can affect ecosystem functioning, with decreased primary productivity being the most frequently reported effect in experimental plant assemblages, including tree plantations. Less is known about the role of biodiversity in natural ecosystems, including forests, despite their importance for global biogeochemical cycling and climate. In general, experimental manipulations of tree diversity will take decades to yield final results. To date, biodiversity effects in natural forests therefore have only been reported from sample surveys or meta-analyses with plots not initially selected for diversity. We studied biomass and growth of subtropical forests stands in southeastern China. Taking advantage of variation in species recruitment during secondary succession, we adopted a comparative study design selecting forest plots to span a gradient in species richness. We repeatedly censored the stem diameter of two tree size cohorts, comprising 93 species belonging to 57 genera and 33 families. Tree size and growth were analyzed in dependence of species richness, the functional diversity of growth-related traits, and phylogenetic diversity, using both general linear and structural equation modeling. Successional age covaried with diversity, but differently so in the two size cohorts. Plot-level stem basal area and growth were positively related with species richness, while growth was negatively related to successional age. The productivity increase in species-rich, functionally and phylogenetically diverse plots was driven by both larger mean sizes and larger numbers of trees. The biodiversity effects we report exceed those from experimental studies, sample surveys and meta-analyses, suggesting that subtropical tree diversity is an important driver of forest productivity and re-growth after disturbance that supports the provision of ecological services by these ecosystems.

  12. Biodiversity promotes tree growth during succession in subtropical forest. (United States)

    Barrufol, Martin; Schmid, Bernhard; Bruelheide, Helge; Chi, Xiulian; Hector, Andrew; Ma, Keping; Michalski, Stefan; Tang, Zhiyao; Niklaus, Pascal A


    Losses of plant species diversity can affect ecosystem functioning, with decreased primary productivity being the most frequently reported effect in experimental plant assemblages, including tree plantations. Less is known about the role of biodiversity in natural ecosystems, including forests, despite their importance for global biogeochemical cycling and climate. In general, experimental manipulations of tree diversity will take decades to yield final results. To date, biodiversity effects in natural forests therefore have only been reported from sample surveys or meta-analyses with plots not initially selected for diversity. We studied biomass and growth of subtropical forests stands in southeastern China. Taking advantage of variation in species recruitment during secondary succession, we adopted a comparative study design selecting forest plots to span a gradient in species richness. We repeatedly censored the stem diameter of two tree size cohorts, comprising 93 species belonging to 57 genera and 33 families. Tree size and growth were analyzed in dependence of species richness, the functional diversity of growth-related traits, and phylogenetic diversity, using both general linear and structural equation modeling. Successional age covaried with diversity, but differently so in the two size cohorts. Plot-level stem basal area and growth were positively related with species richness, while growth was negatively related to successional age. The productivity increase in species-rich, functionally and phylogenetically diverse plots was driven by both larger mean sizes and larger numbers of trees. The biodiversity effects we report exceed those from experimental studies, sample surveys and meta-analyses, suggesting that subtropical tree diversity is an important driver of forest productivity and re-growth after disturbance that supports the provision of ecological services by these ecosystems.

  13. Subtropical circulation, Tibetan Plateau, and Asian Summer Monsoon (United States)

    Wu, G. X.


    The characteristics of the land-air-sea interaction in summer subtropics and their impacts on climate were revealed. It was shown that different kind of diabatic heating plays different roles in the formation of the subtropical circulation where the surface sensible heating associated with the land-sea distribution plays a fundamentally important role, and the three spatial- scales of atmospheric forcing contribute in various ways to the formation of aridity/desert over the western parts of continents and wet/monsoon over the eastern parts. Thus monsoon and desert coexist as twin features. It was identified that the onset of the Asian summer monsoon (ASM) consists of three dynamically consequential stages: the onset first occurs over the eastern Bay of Bengal (BOB) in early May, which is followed by the onset over the South China Sea in mid-May, and the Indian Monsoon onset in early June. During such an onset progression, the formation, maintenance and evolution of the South Asian High (SAH) play a significant role in generating the upper tropospheric dumping. In the lower troposphere, the development of the BOB monsoon onset vortex, the ASM onset barrier, the cross equatorial SST gradient and the forced convection over the eastern Arabian Sea also regulate the onset evolution. In winter the Tibetan Plateau (TP) can inspire a stationary dipole-type atmospheric wave, forming a specific climate pattern in Asia. In spring, such a dipole circulation forms the unique persistent rainfall over Southern China. The TP forcing can also anchor the ASM onset over the BOB by generating the unique short- life BOB SST warm pool and modulating the SAH in the upper troposphere. In summer the thermal forcing of the Tibetan-Iranian Plateau plays a significant role in controlling the Asian monsoon by transporting water vapor from the sea to the land for the genesis of continental monsoon. The TP thermal forcing also modulates the regional climate variability in different time scales.

  14. The fate of fresh and stored 15N-labelled sheep urine and urea applied to a sandy and a sandy loam soil using different application strategies

    DEFF Research Database (Denmark)

    Sørensen, P.; Jensen, E.S.


    The fate of nitrogen from N-15-labelled sheep urine and urea applied to two soils was studied under field conditions. Labelled and stored urine equivalent to 204 kg N ha(-1) was either incorporated in soil or applied to the soil surface prior to sowing of Italian ryegrass (Lolium multiflorum L.),...... mineralized in the sandy loam soil, when urine was applied prior to sowing. Thus, the fertilizer effect of urine N may be significantly lower than that of urea N on fine-textured soils, even when gaseous losses of urine N are negligible.......The fate of nitrogen from N-15-labelled sheep urine and urea applied to two soils was studied under field conditions. Labelled and stored urine equivalent to 204 kg N ha(-1) was either incorporated in soil or applied to the soil surface prior to sowing of Italian ryegrass (Lolium multiflorum L.......), or it was applied to ryegrass one month after sowing. In a sandy loam soil, 62% of the incorporated urine N and 78% of the incorporated urea N was recovered in three cuts of herbage after 5 months. In a sandy soil, 51-53% of the labelled N was recovered in the herbage and the distribution of labelled N in plant...

  15. Maize productivity and mineral N dynamics following different soil fertility management practices on a depleted sandy soil in Zimbabwe

    NARCIS (Netherlands)

    Chikowo, R.; Mapfumo, P.; Nyamugafata, P.; Giller, K.E.


    There is a need for an improved understanding of nitrogen (N) dynamics in depleted sandy soils in southern Africa. A field experiment was conducted to evaluate the performance of different soil fertility improvement practices on a degraded granitic sandy soil in Zimbabwe. Legumes capable of

  16. 76 FR 2703 - Draft Environmental Impact Statement for the Big Sandy Rancheria Band of Western Mono Indians... (United States)


    ... Bureau of Indian Affairs Draft Environmental Impact Statement for the Big Sandy Rancheria Band of Western... Affairs (BIA) as lead agency, with the Big Sandy Rancheria Band of Western Mono Indians (Tribe) as a... and comment and announces the availability of copies of the document and the date, time and location...

  17. Restauração da estrutura do solo por sequências culturais implantadas em semeadura direta, e sua relação com a erosão hídrica em distintas condições físicas de superfície Restoration of the soil structure by crop sequences established in no-till, as related to water erosion in distinct surface physical conditions

    Directory of Open Access Journals (Sweden)

    Jeane Cruz Portela


    , 2007. The six erosion tests, in intervals of about a week, were performed from October to December, 2007. The soil used is an Ultisol, with a sandy clay loam texture in the surface layer and 0.115 m m-1 average slope steepness, and an advanced degree of degradation. The rains were applied with a rotating-boom rainfall simulator, at a constant intensity of 64 mm h-1; for 1-3 h. For this study, water and soil loss data were adjusted to a rainfall duration of 1.5 h. Properties of soil and plants were measured in the experimental plots and water erosion in the surface runoff. The crop sequences and erosion tests influenced the results of the study significantly, with greater differences in the latter than in the former. The erosive process was more influenced by the external or soil surface than the internal or subsurface physical conditions. In general, all crop sequences were effective in restoring the soil structure in the experimental period. The sequence involving teosinte controlled the rainfall erosion process most effectively with regard to soil and water loss and the one involving corn+cowpea and pearl millet with regard to soil loss. The highest soil and water losses in the study were observed from the soil surface with no mobilization and little crop residue cover, regardless of the presence or type of crust, but especially when this latter was slightly cracked prior to rainfall application. The soil surface entirely covered by crop residue, be it untilled or freshly chiseled, controlled runoff effectively and impeded erosion completely. Soil and water losses from the freshly-disked soil surface chiseled a month earlier, although the soil was the most mobilized of all and bare, were practically zero, opposite to what was expected.

  18. Evaluation of a laser land-based mobile mapping system for monitoring sandy coasts

    NARCIS (Netherlands)

    Bitenc, M.; Lindenbergh, R.C.; Khoshelham, K.; Van Waarden, A.P.


    The Dutch coast is characterized by sandy beaches flanked by dunes. Its morphology is essential for the defense against flooding of the hinterland. Therefore it is monitored on a yearly basis by Airborne Laser Scanning (ALS). However, it is recognized that most erosion of the beach and first dune

  19. Study Design and Results of a Population-Based Study on Perceived Stress Following Hurricane Sandy. (United States)

    Schwartz, Rebecca; Liu, Bian; Sison, Cristina; Kerath, Samantha M; Breil, Trista; Murphy, Lisa; Taioli, Emanuela


    Hurricane Sandy was one of the deadliest storms in US history, with at least 162 deaths and numerous injuries. This research aimed to quantify the impact of Hurricane Sandy on the New York metropolitan area. The project included 601 volunteers aged at least 18 years who were recruited in Nassau, Suffolk, Queens, and Richmond counties and Staten Island between 2013 and 2014 through close partnerships with coalition community leaders. Participants completed a self-administered questionnaire on demographics and behavioral factors and a 35-point check off list on hurricane exposure. Perceived stress was assessed by using the 10-item Perceived Stress Scale (PSS). Participants had a mean stress score of 15.6 (SD=7.3; vs general population mean of 13.0), with 30.14% of the sample categorized as "high stress" (mean≥20). In the multivariable regression analysis, age was significantly negatively associated with PSS score. A reported history of mental health issues, Hispanic ethnicity, and overall exposure to Hurricane Sandy were statistically significantly associated with PSS score in a positive direction. Perceived stress was high in areas affected by Hurricane Sandy and was significantly associated with individual hurricane exposure. This study is a first step toward defining what segments of the population are more vulnerable and informing intervention and emergency preparedness efforts. (Disaster Med Public Health Preparedness. 2015;10:325-332).

  20. Rehabilitation of the nematode fauna in a phytostabilized, heavily zinc-contaminated, sandy soil

    NARCIS (Netherlands)

    Bouwman, L.A.; Vangronsveld, J.


    Background, Aim and Scope. The Maatheide in Lommel, Belgium, is an extremely metal contaminated, sandy area where vegetation has disappeared over ca. 130 hectares due to the activities of a former pyrometallurgical zinc smelter. To reduce the environmental impact of this area a rehabilitation

  1. Efficacy of exclosures in conserving local shrub biodiversity in xeric sandy grassland, Inner Mongolia, China (United States)

    Feng-Rui Li; Zhi-Yu Zhou; Li-Ya Zhao; Ai-Sheng Zhang; Ling-Fen Kang


    This study investigated the abundance and frequency of occurrence of all shrub species present in the standing vegetation at four sites, including a 5-year exclosure (protected grassland) and three adjacent unprotected grazing sites that had been subjected to different levels of degradation (light, moderate and severe), in xeric sandy grassland of Inner Mongolia for...

  2. Testing PESTLA using two modellers for bentazone and ethoprophos in a sandy soil

    NARCIS (Netherlands)

    Boesten, J.J.T.I.; Gottesb ren, B.


    Two modellers tested the PESTLA model (version 2.3.1) against results of a field study on bentazone and ethoprophos behaviour in a sandy soil. Both modellers achieved an acceptable description of the measured moisture profiles but only after calibration of the soil hydraulic properties. Both could

  3. Geochemical processes at a fresh/seawater interface in a shallow sandy aquifer

    DEFF Research Database (Denmark)

    Andersen, Martin Søgaard; Iversen, Vibeke Margrethe Nyvang; Postma, Diederik Jan


    Chemical processes in a natural fresh-/seawater mixing zone were studied in a shallow sandy aquifer. The dominant redox-processes are sulfate reduction and methanogenesis. Methanogenesis produces CO2, which causes calcite dissolution. The produced calcium induces ion exchange with sodium. The final...... result of these interactions between different types of geochemical processes is an anoxic groundwater enriched in bicarbonate and sodium....

  4. Changes in the intertidal community structure after a mass mortality event in sandy beaches of Argentina

    NARCIS (Netherlands)

    Dadon, J.R.


    After a massive mortality of the dominant species (the clam Mesodesma mactroides) occurred in 1995, changes in the intertidal community in sandy beaches of Argentina were monitored. Eight sampling stations were established in a 40 km open stretch and samples were taken every October each year up to

  5. A hybrid beach morphology model applied to a high energy sandy beach

    NARCIS (Netherlands)

    Karunarathna, H.; Ranasinghe, Ranasinghe W M R J B; Reeve, D.E.


    In this paper, the application of a hybrid coastal morphodynamic model to forecast inter-annual beach change is discussed through the prediction of beach change in a high energy sandy beach over a period of 5 years. The modelling approach combines a ‘reduced-physics’ formulation with a data-driven

  6. EAARL-B Coastal Topography--Eastern New Jersey, Hurricane Sandy, 2012: First Surface (United States)

    U.S. Geological Survey, Department of the Interior — ASCII xyz and binary point-cloud data, as well as a digital elevation model (DEM) of a portion of the New Jersey coastline, pre- and post-Hurricane Sandy (October...

  7. Contribution of individual sorbents to the control of heavy metal activity in sandy soil

    NARCIS (Netherlands)

    Weng, L.; Temminghoff, E.J.M.; Riemsdijk, van W.H.


    A multisurface model is used to evaluate the contribution of various sorption surfaces to the control of heavy metal activity in sandy soil samples at pH 3.7-6.1 with different sorbent contents. This multisurface model considers soil as a set of independent sorption surfaces, i.e. organic matter

  8. Vertical gradients in the fauna and oxidation of two exposed sandy ...

    African Journals Online (AJOL)

    Vertical profiles of oxygenation and fauna were measured in two exposed sandy beaches. At the less exposed site the whole upper metre of sediment was oxidized although the redox potential discontinuity started at 85 cm. Meiofauna were concentrated in the upper 40 cm and protozoa in the upper 55 cm, but bacteria ...

  9. Limits to intensity of milk production in sandy areas in The Netherlands

    NARCIS (Netherlands)

    Aarts, H.F.M.; Habekotté, B.; Keulen, van H.


    Agricultural land in sandy areas is mainly in use by dairy farms. As a result of intensive fertilisation and irrigation, environmental quality is threatened by lost nutrients and lowered groundwater levels. Therefore, Dutch government put decreasing limits to losses of nutrients, with lowest values

  10. 2012 USACE Post-Hurricane Sandy Topographic LiDAR: Eastern Long Island, New York (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — TASK ORDER NAME: EASTERN LONG ISLAND, NEW YORK LIDAR ACQUISITION FOR HURRICANE SANDY RESPONSE CONTRACT NUMBER: W912P9-10-D-0533 TASK ORDER NUMBER: W81C8X23208588...

  11. Effects of soil moisture content and temperature on methane uptake by grasslands on sandy soils.

    NARCIS (Netherlands)

    Pol-Van Dasselaar, van den A.; Beusichem, van M.L.; Oenema, O.


    Aerobic grasslands may consume significant amounts of atmospheric methane (CH4). We aimed (i) to assess the spatial and temporal variability of net CH4 fluxes from grasslands on aerobic sandy soils, and (ii) to explain the variability in net CH4 fluxes by differences in soil moisture content and

  12. Use of olive mill wastewater (OMW) to decrease hydrophobicity in sandy soil

    NARCIS (Netherlands)

    Diamantis, V.; Pagorogon, L.; Gazani, E.; Doerr, S.H.; Pliakas, F.; Ritsema, C.J.


    This study explores the potential effectiveness of olive mill wastewater (OMW) as an alternative to industrial surfactants in decreasing hydrophobicity in sandy soil. The OMW was obtained from a storage lagoon and characterized by high concentrations of short-chain fatty acids, mainly butyric,


    Directory of Open Access Journals (Sweden)

    Potapov Ivan Aleksandrovich


    Full Text Available Results of calculations and experimental researches of suffosion stability of sandy soils are provided in the article. The authors have assessed the prospects for the application of standard methodologies to demonstrate the need to take account of the filtrate properties in the course of projecting potential suffusion process development patterns typical for sandy soils. The principal attention must be driven to the value of the kinematic viscosity of filtered liquids. Any assessment of filtration-related interaction of the flow of liquid with sandy soils must be backed by the gradation analysis of soils and the analysis of their homogeneity, as well as the mineralogical and morphological analysis. The morphological study of sands of various geneses, performed hereunder, is based on the methodology that takes account of both the shape of sand particles and the structure of their surface. The proposed methodology makes it possible to assess extensive sand specimen rather than separate sand particles to assure the representative sampling to assure the accuracy of the morphological analysis. The authors provide the data that cover the research of sands of various geneses demonstrating varied granulometric and mineral composition, as well as various morphological peculiarities of correlation with the filtrates that have different values of kinematic viscosity. The methodological research completed by the authors has indicated an urgent need to perform laboratory and field researches of suffosion instability of sandy soils in varied geoecological environments typical for urban lands exposed to anthropogenic pollutions.

  14. The Sandy Hook Elementary School shooting as tipping point: "This Time Is Different". (United States)

    Shultz, James M; Muschert, Glenn W; Dingwall, Alison; Cohen, Alyssa M


    Among rampage shooting massacres, the Sandy Hook Elementary School shooting on December 14, 2012 galvanized public attention. In this Commentary we examine the features of this episode of gun violence that has sparked strong reactions and energized discourse that may ultimately lead toward constructive solutions to diminish high rates of firearm deaths and injuries in the United States.

  15. Amelioration of sandy soils in drought stricken areas through use of ...

    African Journals Online (AJOL)


    Uganda Journal of Agricultural Sciences by National Agricultural Research Organisation is licensed under a Creative ... Under field conditions, Ca-bentonite was applied on sandy soils in the drought-prone Lwabiyata sub county, Nakasongola district in ... standard methods (Okalebo et al., 1993). To study the effect of ...

  16. Amelioration of sandy soils in drought stricken areas through use of ...

    African Journals Online (AJOL)

    Soil moisture shortage is a major limiting factor to agricultural production in eastern Africa, in view of increased drought incidences and seasonal rainfall variability. This study evaluated the potential for Ca-bentonite (a 2:1 clay mineral) as a possible amendment for increased moisture retention by sandy soils in drought ...

  17. Modeling the growth and migration of sandy shoals on ebb-tidal deltas

    NARCIS (Netherlands)

    Ridderinkhof, W.; de Swart, H. E.; van der Vegt, M.; Hoekstra, P.


    Coherent sandy shoals that migrate toward the downdrift coast are observed on many ebb-tidal deltas. In this study, processes that cause the growth and migration of shoals on ebb-tidal deltas are identified. Moreover, the effect of the incident wave energy and the tidal prism of an inlet on the

  18. Modelling dune erosion, overwash and breaching at Fire Island (NY) during hurricane Sandy

    NARCIS (Netherlands)

    De Vet, P.L.M.; McCall, R.T.; Den Bieman, J.P.; Stive, M.J.F.; Van Ormondt, M.


    In 2012, Hurricane Sandy caused a breach at Fire Island (NY, USA), near Pelican Island. This paper aims at modelling dune erosion, overwash and breaching processes that occured during the hurricane event at this stretch of coast with the numerical model XBeach. By using the default settings, the

  19. Experimental study on piping in sandy gravel foundations considering effect of overlying clay

    Directory of Open Access Journals (Sweden)

    Shuang Wang


    Full Text Available The influence of the overlying clay on the progression of piping in the sandy gravel foundation of water-retaining structures is often neglected. In order to study this influence, an experimental investigation was conducted on a laboratory-scale model. It was discovered that the critical hydraulic gradient and the area of the piping tunnel increase when the overlying clay thickens. With a thicker clay layer, erosion of the sandy gravel below the clay layer occurs later, but, once the erosion starts, the erosion rate is very high and the average velocity of water seeping through the cross-section of the sandy gravel increases rapidly due to the low deformability of the thick clay layer. Furthermore, it was found that the progression of piping is a complicated and iterative process involving erosion of fine particles, clogging of pores, and flushing of the clogged pores. Two types of erosion have been identified in the progression of piping: one causes the tunnel to advance upstream, and the other increases the depth of the tunnel. The results show that the overlying clay is an important factor when evaluating piping in sandy gravel foundations of water-retaining structures.

  20. 78 FR 46999 - Additional Waivers and Alternative Requirements for Hurricane Sandy Grantees in Receipt of... (United States)


    .... Waiver to permit some activities in support of the tourism industry (State of New York only). In the notice published on April 19, 2013, the Department granted the State of New York a waiver to allow the... several Hurricane Sandy grantees--the State of New York and the State of New Jersey. II. Applicable Rules...

  1. 78 FR 78486 - Notice of Funding Availability for Resilience Projects in Response to Hurricane Sandy (United States)


    .... Estimated repair costs for expected damage events must be supported by engineering reports, transit studies... Federal Transit Administration Notice of Funding Availability for Resilience Projects in Response to Hurricane Sandy AGENCY: Federal Transit Administration (FTA), DOT. ACTION: Notice of funding availability...

  2. Optimising crude oil biodegradation in a sandy loam soil using a ...

    African Journals Online (AJOL)

    The impacts of addition of cow dung and poultry manure alone and in combination with surfactants and/or alternate carbon substrates on crude oil biodegradation in a sandy loam soil were investigated. At a 1.0% (w/w) concentration of the mixture of cow dung and poultry manure, addition of the alternate carbon substrates ...

  3. Spatial and temporal small-scale variation in groundwater quality of a shallow sandy aquifer

    DEFF Research Database (Denmark)

    Bjerg, Poul Løgstrup; Christensen, Thomas Højlund


    The groundwater quality of a shallow unconfined sandy aquifer has been characterized for pH, alkalinity, chloride, nitrate, sulfate, calcium, magnesium, sodium and potassium in terms of vertical and horizontal variations (350 groundwater samples). The test area is located within a farmland lot...

  4. 2012 USACE Post Sandy Topographic LiDAR: Virginia and Maryland (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — TASK ORDER NAME: VIRGINIA AND MARYLAND LIDAR ACQUISITION FOR SANDY RESPONSE CONTRACT NUMBER: W912P9-10-D-0533 TASK ORDER NUMBER: W81C8X2314841 Woolpert Project...

  5. 2012 USACE Post Sandy Topographic LiDAR: Eastern Long Island, New York (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — TASK ORDER NAME: EASTERN LONG ISLAND, NEW YORK LIDAR ACQUISITION FOR SANDY RESPONSE CONTRACT NUMBER: W912P9-10-D-0533 TASK ORDER NUMBER: W81C8X23208588 Woolpert...

  6. Importance of phytodetritus and microphytobenthos for heterotrophs in a shallow subtidal sandy sediment

    NARCIS (Netherlands)

    Evrard, V.; Huettel, M.; Cook, P.L.M.; Soetaert, K.; Heip, C.H.R.; Middelburg, J.J.


    The relative importance of allochthonous phytodetritus deposition and autochthonous microphytobenthos (MPB) production for benthic consumers in an organic carbon (C-org)-poor sandy sediment was assessed using a C-13-stable isotope natural abundance study combined with a dual C-13-tracer addition

  7. Irrigation initiation timing in soybean grown on sandy soils in Northeast Arkansas (United States)

    Irrigation initiation timing was evaluated in furrow-irrigated soybean field with sandy soils in Mississippi County, AR. A major objective of this 2015 study was to validate and expand irrigation timing recommendations that pair plant growth measures with weather cues including use of local weather ...

  8. Lessons from a Disturbance Experiment in the Intertidal Zone of an Exposed Sandy Beach (United States)

    Schoeman, D. S.; Mclachlan, A.; Dugan, J. E.


    Exposed sandy beaches are important, sensitive and widespread coastal habitats. Although they have been studied for more than 50 years, investigators have been reluctant to attempt manipulative experiments due to the dynamic nature of these environments. Consequently, the ecology of exposed sandy beaches remains relatively poorly understood. We conducted a community-level, manipulative experiment involving a simulated anthropogenic disturbance on an exposed microtidal sandy beach in the Eastern Cape, South Africa; the first of its kind and scale. This study comprised pre- and post-impact sampling at an experimental site and two control sites. The impact involved excavating and removing a 200 m2quadrat of sand from the mid-intertidal of the experimental site to a depth of 0·3 m. The intention was to address the prediction that anthropogenic disturbances would be detectable if appropriate spatial and temporal scales were investigated. The following variables were monitored: transect gradient; species richness; macrofaunal abundance; and both the abundance and biomass of the dominant infaunal species, the beach clam Donax serra Röding. Analyses revealed significant differences in temporal patterns of all response variables amongst sites. Some evidence linked these changes to the experimental disturbance, although impacts appear temporary, being ameliorated within, at most, one semi-lunar cycle. This confirms that it is possible to successfully conduct manipulative experiments on exposed sandy beaches. However, the uncontrollable, natural dynamics of the beach face, as expressed by intertidal gradient, contributed significantly to the description of spatio-temporal variation in biotic response variables. It is concluded that to isolate treatment effects from those of natural variation, two advances are necessary on the current research approach. First, experimental designs must take cognizance of the fact that exposed, microtidal sandy beaches have little in common

  9. Assessing the effects of subtropical forest fragmentation on leaf nitrogen distribution using remote sensing data

    CSIR Research Space (South Africa)

    Cho, Moses A


    Full Text Available Subtropical forest loss resulting from conversion of forest to other land-cover types such as grassland, secondary forest, subsistence crop farms and small forest patches affects leaf nitrogen (N) stocks in the landscape. This study explores...

  10. The Role of Subtropical Intrusion in the Development of Typhoon Usagi (5W) 2007

    National Research Council Canada - National Science Library

    DeLeon, Raymund P


    ... of a decaying baroclinic system in the WNP. This analysis of the formation of Usagi points to sub-tropical intrusion of a strong lower-tropospheric baroclinic system undergoing decay as potential seedlings for typhoon formation in areas...

  11. Gooseneck barnacles (Lepas spp.) ingest microplastic debris in the North Pacific Subtropical Gyre

    National Research Council Canada - National Science Library

    Goldstein, Miriam C; Goodwin, Deborah S


    Substantial quantities of small plastic particles, termed "microplastic," have been found in many areas of the world ocean, and have accumulated in particularly high densities on the surface of the subtropical gyres...

  12. Simulation of Greenhouse Management in the Subtropics. Part II: Scenario Study for the Summer Season

    NARCIS (Netherlands)

    Luo, Weihong; Stanghellini, C.; Dai, Jianfeng; Wang, Xiaohan; Zwart, de H.F.; Bu, Chongxing


    Adaptation of a greenhouse climate management strategy to local climate conditions is important for the improvement of resource use efficiency of greenhouse crop production. In this paper the optimal greenhouse climate management under hot, humid, subtropical summer conditions was investigated

  13. Influenza-associated hospitalization in a subtropical city.

    Directory of Open Access Journals (Sweden)

    Chit Ming Wong


    Full Text Available The impact of influenza on morbidity and hospitalization in the tropics and subtropics is poorly quantified. Uniquely, the Hong Kong Special Administrative Region has computerized hospital discharge diagnoses on 95% of total bed days, allowing disease burden for a well-defined population to be accurately assessed.Influenza-associated morbidity and hospitalization was assessed by Poisson regression models for weekly counts of hospitalizations in Hong Kong during 1996 to 2000, using proportions of positive influenza types A (H1N1 and H3N2 and B isolations in specimens sent for laboratory diagnosis as measures of influenza virus circulation. We adjusted for annual trend, seasonality, temperature, and relative humidity, as well as respiratory syncytial virus circulation. We found that influenza was significantly associated with hospitalization for acute respiratory disease (International Classification of Diseases version 9 codes [ICD9] 460-466 and 480-487 and its subcategory pneumonia and influenza (ICD9 480-487 for all age groups. The annual rates of excess hospitalization per 100,000 population for acute respiratory diseases for the age groups 0-14, 15-39, 40-64, 65-74, and 75+ were 163.3 (95% confidence interval [CI], 135-190, 6.0 (95% CI, 2.7-8.9, 14.9 (95% CI, 10.7-18.8, 83.8 (95% CI, 61.2-104.2, and 266 (95% CI, 198.7-330.2, respectively. Influenza was also associated with hospitalization for cerebrovascular disease (ICD9 430-438 for those aged over 75 y (55.4; 95% CI, 23.1-87.8; ischemic heart disease (ICD9 410-414 for the age group 40-64 y (5.3; 95% CI, 0.5-9.5 and over 75 y (56.4; 95% CI, 21.1-93.4; and diabetes mellitus (ICD9 250 for all age groups older than 40 y.Influenza has a major impact on hospitalization due to cardio-respiratory diseases as well as on cerebrovascular disease, ischemic heart disease, and diabetes mellitus in the tropics and subtropics. Better utilization of influenza vaccine during annual epidemics in the tropics

  14. Nitrate source apportionment in a subtropical watershed using Bayesian model. (United States)

    Yang, Liping; Han, Jiangpei; Xue, Jianlong; Zeng, Lingzao; Shi, Jiachun; Wu, Laosheng; Jiang, Yonghai


    Nitrate (NO3-) pollution in aquatic system is a worldwide problem. The temporal distribution pattern and sources of nitrate are of great concern for water quality. The nitrogen (N) cycling processes in a subtropical watershed located in Changxing County, Zhejiang Province, China were greatly influenced by the temporal variations of precipitation and temperature during the study period (September 2011 to July 2012). The highest NO3- concentration in water was in May (wet season, mean±SD=17.45±9.50 mg L(-1)) and the lowest concentration occurred in December (dry season, mean±SD=10.54±6.28 mg L(-1)). Nevertheless, no water sample in the study area exceeds the WHO drinking water limit of 50 mg L(-1) NO3-. Four sources of NO3(-) (atmospheric deposition, AD; soil N, SN; synthetic fertilizer, SF; manure & sewage, M&S) were identified using both hydrochemical characteristics [Cl-, NO3-, HCO3-, SO42-, Ca2+, K+, Mg2+, Na+, dissolved oxygen (DO)] and dual isotope approach (δ15N-NO3- and δ(18)O-NO3-). Both chemical and isotopic characteristics indicated that denitrification was not the main N cycling process in the study area. Using a Bayesian model (stable isotope analysis in R, SIAR), the contribution of each source was apportioned. Source apportionment results showed that source contributions differed significantly between the dry and wet season, AD and M&S contributed more in December than in May. In contrast, SN and SF contributed more NO3- to water in May than that in December. M&S and SF were the major contributors in December and May, respectively. Moreover, the shortcomings and uncertainties of SIAR were discussed to provide implications for future works. With the assessment of temporal variation and sources of NO3-, better agricultural management practices and sewage disposal programs can be implemented to sustain water quality in subtropical watersheds. Copyright © 2013 Elsevier B.V. All rights reserved.

  15. Spatial and temporal patterns of eastern Australia subtropical coral communities.

    Directory of Open Access Journals (Sweden)

    Steven J Dalton

    Full Text Available Despite increases in the frequency and intensity of disturbances on coral reefs over the past few decades, the response of subtropical coral assemblages to climate change is poorly understood. To address this knowledge gap on Australian reefs and provide a baseline for future comparisons, we quantified spatial (10-100's of kilometres and temporal (decadal patterns of benthic assemblages across a latitudinal gradient along the east Australian coastline (23.5° S to 31.5° S. Benthic community composition was quantified at six locations from the southern Great Barrier Reef, Queensland (Heron Reef, 23.5° S, 152° E to northern New South Wales (31° S, 153.1° E and at Lord Howe Island (31.5° S, 159.1° E. Our results indicate significant latitudinal differences in benthic assemblages, while community composition at some sites was more similar to those hundreds of kilometres away than to that of neighbouring reefs. A general trend was observed with decreasing cover of Acroporidae with increasing latitude, corresponding with an increasing cover of Pocilloporidae and Dendrophylliidae. Heron Reef comprised a high proportion of Acropora corals (43% total coral cover and coralline algae (44%. In contrast, high-latitude reefs were dominated by mixed coral assemblages (0-52% and high macroalgal cover (16-27%. Decadal comparisons of high-latitude reefs showed regional stability of benthic assemblages (9 out of 11 assemblages remained stable at > 75% similarity, during a period of warming oceans (0.15-0.24°C per decade. Such temporal stability suggests that eastern Australian subtropical communities may be more resistant than tropical reef communities that have experienced assembly shifts caused by perturbations associated with recent global climate change. Despite the clear differences in the structure of coral assemblages evident in our spatial surveys, we suggest that the temporal stability of high-latitude reefs may provide a limited refuge for

  16. Enhanced warming of the subtropical mode water in the North Pacific and North Atlantic (United States)

    Sugimoto, Shusaku; Hanawa, Kimio; Watanabe, Tomowo; Suga, Toshio; Xie, Shang-Ping


    Over the past six decades, the subtropical surface ocean has warmed at rates close to those of global mean surface ocean temperature except in western boundary current regions where the surface warming is locally enhanced by a factor of two. Changes in the subsurface ocean, however, remain unclear because of lack of data. Compiling historical temperature measurements--some available for the first time--here we show that the subtropical mode water has warmed over the past six decades in both the North Pacific and North Atlantic. The rate of the warming is twice as large in the mode waters than at the surface. Subtropical mode waters are important water masses of vertically uniform temperature that are a few hundred metres thick and distributed widely in the main thermocline of the subtropical oceans. The enhanced warming of subtropical mode waters can be traced back to the surface warming in the formation regions along the western boundary current extensions. Furthermore, we detect increased temperature stratification and decreased dissolved oxygen in the subtropical mode waters. The latter change has clear implications for predicting biogeochemical responses to climate warming.

  17. The 2014 summer coral bleaching event in subtropical Hong Kong. (United States)

    Xie, James Y; Lau, Dickey C C; Kei, Keith; Yu, Vriko P F; Chow, Wing-Kuen; Qiu, Jian-Wen


    We reported a coral bleaching event that occurred in August-September 2014 in Hong Kong waters based on video transect surveys conducted at eight sites. The bleaching affected eight species of corals with different growth forms. Bleaching at seven of the eight study sites was minor, affecting only 0.4-5.2% colonies and 0.8-10.0% coral-covered area. Sharp Island East, however, suffered from a moderate level of bleaching, with 13.1% colonies and 30.1% coral-covered area affected. Examination of the government's environmental monitoring data indicated abnormal water quality conditions preceding and during the bleaching event. Follow-up field surveys of tagged colonies showed that 76% of them had fully recovered, 12% partially recovered, and 12% suffered from mortality. These results indicate that the subtropical corals of Hong Kong are not immune to bleaching, and there is a need to study their responses under climate change scenarios. Copyright © 2016. Published by Elsevier Ltd.

  18. Eddy properties in the Subtropical Countercurrent, Western Philippine Sea (United States)

    Ramp, S. R.; Colosi, J. A.; Worcester, P. F.; Bahr, F. L.; Heaney, K. D.; Mercer, J. A.; Van Uffelen, L. J.


    An array of six oceanographic moorings with acoustic and environmental sensors was deployed in the central Philippine Sea from April 2010 to April 2011. The location spanned 18-23°N, 124 - 130°E in the Subtropical Countercurrent (STCC). The most prominent feature of the data set was a densely-packed eddy field with about equal numbers of cyclones and anticyclones moving westward at 6-12 km d-1. Eddies of either sign displaced the thermocline about ±50 m and had surface velocities exceeding 110 cm s-1. While warm eddies were slightly larger than cold eddies, the distance to maximum radial velocity was similar for both at about 65 km, close to the local Rossby radius of deformation. The steepness parameter U/c in the eddies ranged from 3 to 10, accompanied by relative vorticity of order 0.1-0.3 f, suggesting nonlinear, quasigeostrophic features with trapped cores rather than linear waves. This was borne out by the water mass analysis which showed high salinity, high spice North Pacific Tropical Water (NPTW) being transported westward in the warm eddy cores. The total KE and APE in eddies of both signs was about 1×1015 J with 85% of the APE and 74% of the KE located above 250 m depth. This equipartitioning of energy suggests mature eddies near equilibrium, that had been evolving for some time as they propagated into the area from the east.


    Directory of Open Access Journals (Sweden)

    Hamilton Luiz Munari Vogel


    Full Text Available In the above ground biomass of a native forest or plantation are stored large quantities of nutrients, with few studies in the literature, especially concerning micronutrients. The present work aimed to quantify the micronutrients in above ground biomass in a Seasonal Subtropical forest in Itaara-RS, Brazil. For the above ground biomass evaluation, 20 trees of five different diameter classes were felled. The above ground biomass was separated in the following compartments: stem wood, stem bark, branches and leaves. The contents of B, Cu, Fe, Mn and Zn in the biomass samples were determined. The stock of micronutrients in the biomass for each component was obtained based on the estimated dry biomass, multiplied by the nutrient content. The total production of above ground biomass was estimated at 210.0 Mg.ha-1. The branches, stem wood, stem bark and leaves corresponded to 48.8, 43.3, 5.4 and 2.4% of the above ground biomass. The lower levels of B, Cu, Fe and Mn are in stem wood, except for Zn; in the branches and trunk wood are the largest stocks of B, Cu, Fe and Mn. In the branches, leaves and trunk bark are stored most micronutrients, pointing to the importance of these to remain on the soil.

  20. Modeling and evaluation of greenhouse for floriculture in subtropics

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, K.S.; Jha, Madan K.; Tiwari, K.N.; Singh, Amanpreet [Agricultural and Food Engineering Department, Indian Institute of Technology, Kharagpur 721302 (India)


    Greenhouse technology provides favorable microclimate for year round cultivation of crops. Floricultural production in the greenhouse is an attractive venture for subtropical India due to its economic and aesthetic value. However, production and quality of flowers suffer due to high summer temperatures. Hence, development of a reliable model to predict the microclimate of greenhouse is necessary to manage the crop production and to optimize the design. Experiments were conducted in two different shape and size of greenhouses to evaluate the microclimate and crop performance. A simple dynamic model was developed to predict air temperature, vapor pressure and canopy temperatures. Submodels of natural ventilation and crop transpiration constituted the sensible and latent heat transfers in the greenhouse. The model was validated for Gerbera crop cultivation during winter and summer seasons. Good agreement was found between the predicted and observed values of temperature with RMSE values of 0.73 C and 0.87 C during winter and summer seasons, respectively. Sensitivity analysis of the model showed that width of side opening and angle of roof vent influenced the model performance considerably. It was concluded that the model can be used as a design tool for prediction of microclimate in the greenhouse for floricultural production. (author)

  1. Phylogenetic congruence between subtropical trees and their associated fungi. (United States)

    Liu, Xubing; Liang, Minxia; Etienne, Rampal S; Gilbert, Gregory S; Yu, Shixiao


    Recent studies have detected phylogenetic signals in pathogen-host networks for both soil-borne and leaf-infecting fungi, suggesting that pathogenic fungi may track or coevolve with their preferred hosts. However, a phylogenetically concordant relationship between multiple hosts and multiple fungi in has rarely been investigated. Using next-generation high-throughput DNA sequencing techniques, we analyzed fungal taxa associated with diseased leaves, rotten seeds, and infected seedlings of subtropical trees. We compared the topologies of the phylogenetic trees of the soil and foliar fungi based on the internal transcribed spacer (ITS) region with the phylogeny of host tree species based on matK, rbcL, atpB, and 5.8S genes. We identified 37 foliar and 103 soil pathogenic fungi belonging to the Ascomycota and Basidiomycota phyla and detected significantly nonrandom host-fungus combinations, which clustered on both the fungus phylogeny and the host phylogeny. The explicit evidence of congruent phylogenies between tree hosts and their potential fungal pathogens suggests either diffuse coevolution among the plant-fungal interaction networks or that the distribution of fungal species tracked spatially associated hosts with phylogenetically conserved traits and habitat preferences. Phylogenetic conservatism in plant-fungal interactions within a local community promotes host and parasite specificity, which is integral to the important role of fungi in promoting species coexistence and maintaining biodiversity of forest communities.

  2. Plastic pollution in the South Pacific subtropical gyre. (United States)

    Eriksen, Marcus; Maximenko, Nikolai; Thiel, Martin; Cummins, Anna; Lattin, Gwen; Wilson, Stiv; Hafner, Jan; Zellers, Ann; Rifman, Samuel


    Plastic marine pollution in the open ocean of the southern hemisphere is largely undocumented. Here, we report the result of a (4489 km) 2424 nautical mile transect through the South Pacific subtropical gyre, carried out in March-April 2011. Neuston samples were collected at 48 sites, averaging 50 nautical miles apart, using a manta trawl lined with a 333 μm mesh. The transect bisected a predicted accumulation zone associated with the convergence of surface currents, driven by local winds. The results show an increase in surface abundance of plastic pollution as we neared the center and decrease as we moved away, verifying the presence of a garbage patch. The average abundance and mass was 26,898 particles km(-2) and 70.96 g km(-2), respectively. 88.8% of the plastic pollution was found in the middle third of the samples with the highest value of 396,342 particles km(-2) occurring near the center of the predicted accumulation zone. Copyright © 2013 Elsevier Ltd. All rights reserved.


    Directory of Open Access Journals (Sweden)

    Marcelo Eduardo Freres Stipp


    Full Text Available The sandy lands are a process of scouring with sand forming a sandy area, which correspondsto a reworking of the sands due its constant mobility, involving the transformation of notsolids deposits is sandy areas. This work tried to establish the characterization of thisphenomenon of scouring with sand in a local level, occurring in arenaceous areas in theNortheast of the state of Paraná, specifically in the urban site of Paranavaí. It was also madean evaluation of the environmental degradation as well as different causes for what provokedthese sandy areas. Being an area with a high level of soil decomposition with the highwaysroutes crossing it, it was necessary, besides bibliographic data that allowed a theoretical basis,a research applied in order to supply subsides for future planning related to the spaceorganization. The evolution of the use and soil occupation in this area has been processedwithin an urban planning which considered by no account neither soil characteristic, thevegetation nor the predominant climate in that region. The mechanisms of region atmospherecirculation were analyzed, the alterations or attributes of the climate as well, aiming toidentify the genesis of the erosion sandy and possible time and space distribution. Initially, themain characteristics of the region were collected, components e processes working on the landmodel. It was observed how it worked and the use and occupation of the soil in past times andcurrently. During 2004, using the Environmental Fragility Letter, the areas of erosion wereidentified, ravines and strong erosion that compounds the first stages of the focused problem.The sandy land is a process that involves erosion, transport, e accumulation, meaning most oftimes the loosing of Biosphere productivity. For monitoring these risk areas some measuringcanes were made to measure the soil loss, which were used in several spots of erosion in theurban area in Paranavaí. The measurement happened in

  4. Near-real-time Forensic Disaster Analysis: experiences from hurricane Sandy (United States)

    Kunz, Michael; Mühr, Bernhard; Schröter, Kai; Kunz-Plapp, Tina; Daniell, James; Khazai, Bijan; Wenzel, Friedemann; Vannieuwenhuyse, Marjorie; Comes, Tina; Münzberg, Thomas; Elmer, Florian; Fohringer, Joachim; Lucas, Christian; Trieselmann, Werner; Zschau, Jochen


    Hurricane Sandy was the last tropical cyclone of the 2012 Northern Atlantic Hurricane season that made landfall. It moved on an unusual track from the Caribbean to the East Coast of the United States from 24 to 30 October as a Category 1 and 2 Hurricane according to the Saffir-Simpson Scale. Along its path, the severe storm event caused widespread damage including almost 200 fatalities. In the early hours of 30 October, Sandy made landfall near Atlantic City, N.J. Sandy was an extraordinary event due to its multihazard nature and several cascading effects in the aftermath. From the hydro-meteorological perspective, most unusual was the very large spatial extent of up to 1,700 km. High wind speeds were associated with record breaking storm surges at the U.S. Mid- Atlantic and New England Coast during high (astronomical) tide, leading to widespread flooding. Though Sandy was not the most severe storm event in terms of wind speed and precipitation, the impact in the U.S. was enormous with total damage estimates of up to 90 billion US (own estimate from Dec. 2012). Although much better data emerge weeks after such an event, the Forensic Disaster Analysis (FDA) Task Force of the Center for Disaster Management and Risk Reduction Technology (CEDIM) made an effort to obtain a comprehensive and holistic overview of the causes, hazardous effects and consequences associated with Sandy immediately after landfall at the U.S. coast on 30 October 2012. This was done in an interdisciplinary way by collecting and compiling scattered and distributed information from available databases and sources via the Internet, by applying own methodologies and models for near-real time analyses developed in recent years, and by expert knowledge. This contribution gives an overview about the CEDIM-FDA analyses' results. It describes the situation that led to the extraordinary event, highlights the interaction of the tropical cyclone with other hydro-meteorological events, and examines the

  5. Rheological Parameters as Affected by Water Tension in Subtropical Soils

    Directory of Open Access Journals (Sweden)

    Patricia Pértile


    Full Text Available ABSTRACT Rheological parameters have been used to study the interaction between particles and the structural strength of soils subjected to mechanical stresses, in which soil composition and water content most strongly affect soil resistance to deformation. Our objective was to evaluate the effect of water tension on rheological parameters of soils with different mineralogical, physical, and chemical composition. Surface and subsurface horizons of four Oxisols, two Ultisols, one Alfisol, and one Vertisol were physically and chemically characterized; their rheological parameters were obtained from amplitude sweep tests under oscillatory shear on disturbed soil samples that were saturated and subjected to water tension of 1, 3, 6, and 10 kPa. In these samples, the rheological parameters linear viscoelastic deformation limit (γL, maximum shear stress (τmax, and integral z were determined. By simple regression analysis of the rheological parameters as a function of soil water tension, we observed increased mechanical strength with increasing water tension up to at least 6 kPa, primarily due to increased capillary forces in the soil. However, increased elasticity assessed by γL was not as expressive as the increase in structural rigidity assessed by τmax and integral z. Elastic deformation of the soil (γL increases with the increase in the number of bonds among particles, which depend on the clay, total carbon, expansive clay mineral, and cation contents; however, maximum shear resistance (τmax and structural stiffness (integral z mainly increase with clay, kaolinite, and oxide content by increasing the strength of interparticle bonds. A decrease in mechanical strength occurs for water tension of 10 kPa (the lowest water content evaluated in sandy horizons or in horizons with a high proportion of resistant microaggregates (pseudosand, when associated with low bulk density, due to fewer points of contact between soil particles and therefore

  6. Nitrogen and Carbon Leaching in Repacked Sandy Soil with Added Fine Particulate Biochar

    DEFF Research Database (Denmark)

    Bruun, Esben W.; Petersen, Carsten; Strobel, Bjarne W.


    of leachate came to about 3.0 water filled pore volumes (WFPVs). Our study revealed a high mobility of labile C components originating from the fine particulate fast pyrolysis biochar. This finding highlights a potential risk of C leaching coupled with the use of fast pyrolysis biochars for soil amendment......Biochar amendment to soil may affect N turnover and retention, and may cause translocation of dissolved and particulate C. We investigated effects of three fine particulate biochars made of wheat (Triticum aestivum L.) straw (one by slow pyrolysis and two by fast pyrolysis) on N and C leaching from...... repacked sandy soil columns (length: 51 cm). Biochar (2 wt%), ammonium fertilizer (NH4+, amount corresponding to 300 kg N ha-1) and an inert tracer (bromide) were added to a 3-cm top layer of sandy loam, and the columns were then irrigated with constant rate (36 mm d-1) for 15 d. The total amount...

  7. Hurricane Sandy Economic Impacts Assessment: A Computable General Equilibrium Approach and Validation

    Energy Technology Data Exchange (ETDEWEB)

    Boero, Riccardo [Los Alamos National Laboratory; Edwards, Brian Keith [Los Alamos National Laboratory


    Economists use computable general equilibrium (CGE) models to assess how economies react and self-organize after changes in policies, technology, and other exogenous shocks. CGE models are equation-based, empirically calibrated, and inspired by Neoclassical economic theory. The focus of this work was to validate the National Infrastructure Simulation and Analysis Center (NISAC) CGE model and apply it to the problem of assessing the economic impacts of severe events. We used the 2012 Hurricane Sandy event as our validation case. In particular, this work first introduces the model and then describes the validation approach and the empirical data available for studying the event of focus. Shocks to the model are then formalized and applied. Finally, model results and limitations are presented and discussed, pointing out both the model degree of accuracy and the assessed total damage caused by Hurricane Sandy.

  8. Attitudes towards relocation following Hurricane Sandy: should we stay or should we go? (United States)

    Bukvic, Anamaria; Owen, Graham


    This study explores the dilemma of whether to rebuild or relocate from the areas devastated by Hurricane Sandy in 2012. Since disasters represent the discernible manifestation of other complex coastal hazards, they offer a window of opportunity to engage residents in the dialogue on relocation as sometimes the most effective risk reduction strategy. The following research evaluates attitudes towards relocation and willingness to consider buyout among 46 surveyed households located in highly-affected communities five months after Sandy. It also gauges perceptions of coastal risks and recovery concerns as drivers of relocation, the level of support for different adaptation strategies, and preferences related to the relocation process itself on how and where to relocate and with what type of assistance. Responses indicate that, even though residents prefer structural solutions to address coastal hazards, they are not fully opposed to the possibility of relocation mostly for personal health and safety reasons. © 2017 The Author(s). Disasters © Overseas Development Institute, 2017.

  9. Fine organic particles in a sandy beach system (Puck Bay, Baltic Sea

    Directory of Open Access Journals (Sweden)

    Lech Kotwicki


    Full Text Available A total of over 550 samples of particulate organic matter (POM were obtained from swash and groundwater samples taken on a monthly basis from seven localities on the sandy shores of Puck Bay in 2002 and 2003. Sandy sediment cores from the swash zone were collected to assess the amount of POM in the pore waters. The mean annual concentrations of POM varied between localities from 20 to 500 mg in groundwater and from 6 to 200 mg dm-3 in swash water. The carbon/nitrogen (C/N ratio in suspended matter was always higher in groundwater (annual mean 12 than in swash water (annual mean 7. The C/N ratio indicates a local, algal origin of POM in the shallow coastal zone.


    Directory of Open Access Journals (Sweden)

    Katarzyna Kamińska


    Full Text Available The paper aimed at the determination of the California Bearing Ratio of a stabilised and unstabilised fine-grained mineral soil. A clayey-sandy silt with the addition of 3, 6 and 10% of road stabilisers Solidex and Solidex A was used for the tests. The tests were carried out in the press Tritech 50 at the loading of 22 and 44 N. The stabilised samples were subjected to 7-days treatment, whereas unstabilised 4-days treatment. Stabilization with the applied road binders brought positive effects, there occurred a significant improvement in the mechanical properties of the clayey-sandy silt. The better binder, which significantly increased the value of the CBR ratio, was Solidex A. The use of hydraulic binders is of a great importance in road building, because their addition improves the mechanical properties of weaker mineral soils.

  11. Transitions in climate and energy discourse between Hurricanes Katrina and Sandy

    CERN Document Server

    Cody, Emily M; Bagrow, James P; Dodds, Peter Sheridan; Danforth, Christopher M


    Although climate change and energy are intricately linked, their explicit connection is not always prominent in public discourse and the media. Disruptive extreme weather events, including hurricanes, focus public attention in new and different ways, offering a unique window of opportunity to analyze how a focusing event influences public opinion. Simultaneously shaping and reflecting public discourse, media coverage of extreme weather events reflects public opinion of climate issues. Here we analyze climate and energy media coverage of Hurricanes Katrina (2005) and Sandy (2012) using topic models, mathematical techniques used to discover abstract topics within a set of documents. Our results demonstrate that post-Katrina media coverage does not contain a climate change topic, and the energy topic is limited to discussion of energy prices, markets, and the economy with almost no explicit linkages made between energy and climate change. In contrast, post-Sandy media coverage does contain a prominent climate ch...

  12. Sensitivity of leachate and fine contents on electrical resistivity variations of sandy soils. (United States)

    Yoon, G L; Park, J B


    Laboratory pilot tests were performed to investigate the relationship between electrical resistivity and contaminated soil properties. Three different sandy soils and leachate collected from one of the industrial waste landfill sites in Korea were mixed to simulate contaminated soil conditions. The values of electrical resistivity of the soils were measured using laboratory scaled resistivity cone penetrometer probe. In the experiments, electrical resistivity was observed in terms of water content, unit weight, saturation degree of the soils, and leachate concentration. The experimental results show that the electrical resistivity of the sandy soils depends largely on the water content and electrical properties of pore water rather than unit weight and types of soils. The amount of fines can have significant effect on electrical properties of soils. Direct correlation with contamination in such soils may not be valid here. The results suggest that the electrical resistivity measurement is well suited and applicable for monitoring and delineation of contaminants in the subsurface.

  13. Coastal Topography--Northeast Atlantic Coast, Post-Hurricane Sandy, 2012: Lidar and digital elevation model (DEM) tile index (United States)

    U.S. Geological Survey, Department of the Interior — This data represents the tile index for lidar data collected for the U.S. Geological Survey in November 2012 following Hurricane Sandy, which made landfall in the...

  14. The Effect of Chloride and Sulfate Ions on the Adsorption of Cd 2+ on Clay and Sandy Loam Egyptian Soils

    National Research Council Canada - National Science Library

    Mohamed E. EL-Hefnawy; Elmetwaly M. Selim; Faiz F. Assaad; Ali I. Ismail


      Adsorption of Cd2+ on two types of Egyptian soils: clay (alluvial) and sandy loam (calcareous), was studied. Effect of changing the matrix electrolyte type and concentration was used to mimic the natural soil salts...

  15. The Effect of Chloride and Sulfate Ions on the Adsorption of Cd2+on Clay and Sandy Loam Egyptian Soils

    National Research Council Canada - National Science Library

    EL-Hefnawy, Mohamed E; Selim, Elmetwaly M; Assaad, Faiz F; Ismail, Ali I


    Adsorption of Cd2+ on two types of Egyptian soils: clay (alluvial) and sandy loam (calcareous), was studied. Effect of changing the matrix electrolyte type and concentration was used to mimic the natural soil salts...

  16. The effect of chloride and sulfate ions on the adsorption of Cd2+ on clay and sandy loam Egyptian soils

    National Research Council Canada - National Science Library

    El-Hefnawy, Mohamed E; Selim, Elmetwaly M; Assaad, Faiz F; Ismail, Ali I


    Adsorption of Cd(2+) on two types of Egyptian soils: clay (alluvial) and sandy loam (calcareous), was studied. Effect of changing the matrix electrolyte type and concentration was used to mimic the natural soil salts...

  17. Gateway National Recreational Area - Sandy Hook Unit : automated fee entrance plaza and intelligent transportation system technical requirements (United States)


    The Volpe National Transportation Systems Center (Volpe Center) is providing technical : support to Sandy Hook, a unit of the Gateway National Recreation Area, in the planning and : concept development for possible Intelligent Transportation Systems ...

  18. 2013-2014 U.S. Geological Survey CMGP LiDAR: Post Sandy (New York City) (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — TASK NAME: USGS New York CMGP Sandy Lidar 0.7 Meter NPS LIDAR lidar Data Acquisition and Processing Production Task USGS Contract No. G10PC00057 Task Order No....

  19. Morpho-physiological characterization of soybean genotypes under subtropical environment

    Directory of Open Access Journals (Sweden)

    Al-Hadi Gaffar M.A.


    Full Text Available Soybean is a promising oilseed crop in rice-based cropping systems in South and Southeast Asia. In spite of immense scope of its expansion, the crop is not being popular to the farmers because of poor yield of the existing cultivars. Therefore, this study evaluated eighty-soybean genotypes of diverse growth habits with a view to searching genotype(s of desirable morpho-physiological characters and high yield potential. Sixteen quantitative plant traits were evaluated to classify the genotypes into different groups using various multivariate methods. A wide range of variation was found in almost all qualitative plant traits. The study reveals that plants tend to become taller as the phenological cycle is longer. Seed yield was the product of the number of pods per plant, pod weight and seeds per pod. The first three components of principal component analysis explained 75% of the total variations of the soybean genotypes. Using Dendrogram from cluster analysis, the genotypes were grouped into six clusters. The maximum number of genotypes was concentrated in cluster 5 followed by clusters 4. The phenology, plant height, the number of pods and seed yield were the important discriminating variables in grouping the genotypes. The number of pods per plant displayed the principal role in explaining the maximum variance in the genotypes. The clustering pattern of the genotypes revealed that the genotypes under cluster 2 and cluster 6 were long statures, late maturing and produced higher seed yield. The genotype G00003 under cluster 2 is the best entry giving the highest seed yield. From cluster 6, the genotype G00209 could be the better choice for much better seed yield. The cluster 3 genotypes were comparatively early maturing and gave reasonable yield. It is concluded that the genotypes under clusters 2 and 6 and 3 can be important resources for developing a high yielding variety and sustainability of growing soybean in the subtropical conditions.

  20. Ammonia emission from subtropical crop land area in India (United States)

    Datta, A.; Sharma, S. K.; Harit, R. C.; Kumar, V.; Mandal, T. K.; Pathak, H.


    Ammonia (NH3) emission from wheat (November to April) and rice (July to October) crops was measured using the chemiluminescence method at a subtropical agricultural area of India during 2009-2010. Samples were collected from the canopy height during different growth stages of wheat crop to study the variations of NH3 emission during different growth stages of the crop. Background atmospheric concentration of NH3 was measured at 5 m height at the study site. Background NH3 concentration was subtracted from the NH3 concentration at crop canopy height to estimate the emission of NH3 from crop canopy. The NH3 emission from the wheat crop were recorded as 33.3 to 57.0; 15.3 to 29.2; 10.3 to 28.0; 8.7 to 23.9 and 13.9 to 28.9 μg m-2 d-1 during sowing, crown root initiation (CRI), panicle initiation, grain filling and maturity stages of the crop respectively. The NH3 emission followed a diurnal pattern with significant correlation with ambient temperature at different crop growth stages. Cumulative seasonal NH3 emission to the atmosphere was accounted for the loss of ˜10% of applied N-fertilizer during the wheat crop growing period. Immediate increase in NH3 emission was recorded from rice crop, grown under temperature gradient tunnel (TGT). However, the NH3 emission inside the TGT decreases within 3-4 h after the N-fertilizer application. Continuous estimation of NH3 concentration at the crop canopy inside the TGT, suggests that the NH3 emission to the atmosphere reaches its peak within ˜20 h of N-fertilizer application and continues up to 5 d following a diurnal pattern.

  1. Transport in the Subtropical Lowermost Stratosphere during CRYSTAL-FACE (United States)

    Pittman, Jasna V.; Weinstock, elliot M.; Oglesby, Robert J.; Sayres, David S.; Smith, Jessica B.; Anderson, James G.; Cooper, Owen R.; Wofsy, Steven C.; Xueref, Irene; Gerbig, Cristoph; hide


    We use in situ measurements of water vapor (H2O), ozone (O3), carbon dioxide (CO2), carbon monoxide (CO), nitric oxide (NO), and total reactive nitrogen (NO(y)) obtained during the CRYSTAL-FACE campaign in July 2002 to study summertime transport in the subtropical lowermost stratosphere. We use an objective methodology to distinguish the latitudinal origin of the sampled air masses despite the influence of convection, and we calculate backward trajectories to elucidate their recent geographical history. The methodology consists of exploring the statistical behavior of the data by performing multivariate clustering and agglomerative hierarchical clustering calculations, and projecting cluster groups onto principal component space to identify air masses of like composition and hence presumed origin. The statistically derived cluster groups are then examined in physical space using tracer-tracer correlation plots. Interpretation of the principal component analysis suggests that the variability in the data is accounted for primarily by the mean age of air in the stratosphere, followed by the age of the convective influence, and lastly by the extent of convective influence, potentially related to the latitude of convective injection [Dessler and Sherwuud, 2004]. We find that high-latitude stratospheric air is the dominant source region during the beginning of the campaign while tropical air is the dominant source region during the rest of the campaign. Influence of convection from both local and non-local events is frequently observed. The identification of air mass origin is confirmed with backward trajectories, and the behavior of the trajectories is associated with the North American monsoon circulation.

  2. Nitric Acid Uptake on Subtropical Cirrus Cloud Particles (United States)

    Popp, P. J.; Gao, R. S.; Marcy, T. P.; Fahey, D. W.; Hudson, P. K.; Thompson, T. L.; Kaercher, B.; Ridley, B. A.; Weinheimer, A. J.; Knapp, D. J.; hide


    The redistribution of HNO3 via uptake and sedimentation by cirrus cloud particles is considered an important term in the upper tropospheric budget of reactive nitrogen. Numerous cirrus cloud encounters by the NASA WB-57F high-altitude research aircraft during the Cirrus Regional Study of Tropical Anvils and Cirrus Layers-Florida Area Cirrus Experiment (CRYSTAL-FACE) were accompanied by the observation of condensed-phase HNO3 with the NOAA chemical ionization mass spectrometer. The instrument measures HNO3 with two independent channels of detection connected to separate forward and downward facing inlets that allow a determination of the amount of HNO3 condensed on ice particles. Subtropical cirrus clouds, as indicated by the presence of ice particles, were observed coincident with condensed-phase HNO3 at temperatures of 197-224 K and pressures of 122-224 hPa. Maximum levels of condensed-phase HNO3 approached the gas-phase equivalent of 0.8 ppbv. Ice particle surface coverages as high as 1.4 # 10(exp 14) molecules/ square cm were observed. A dissociative Langmuir adsorption model, when using an empirically derived HNO3 adsorption enthalpy of -11.0 kcal/mol, effectively describes the observed molecular coverages to within a factor of 5. The percentage of total HNO3 in the condensed phase ranged from near zero to 100% in the observed cirrus clouds. With volume-weighted mean particle diameters up to 700 ?m and particle fall velocities up to 10 m/s, some observed clouds have significant potential to redistribute HNO3 in the upper troposphere.

  3. Diagnostics of subtropical plants functional state by cluster analysis

    Directory of Open Access Journals (Sweden)

    Oksana Belous


    Full Text Available The article presents an application example of statistical methods for data analysis on diagnosis of the adaptive capacity of subtropical plants varieties. We depicted selection indicators and basic physiological parameters that were defined as diagnostic. We used evaluation on a set of parameters of water regime, there are: determination of water deficit of the leaves, determining the fractional composition of water and detection parameters of the concentration of cell sap (CCS (for tea culture flushes. These settings are characterized by high liability and high responsiveness to the effects of many abiotic factors that determined the particular care in the selection of plant material for analysis and consideration of the impact on sustainability. On the basis of the experimental data calculated the coefficients of pair correlation between climatic factors and used physiological indicators. The result was a selection of physiological and biochemical indicators proposed to assess the adaptability and included in the basis of methodical recommendations on diagnostics of the functional state of the studied cultures. Analysis of complex studies involving a large number of indicators is quite difficult, especially does not allow to quickly identify the similarity of new varieties for their adaptive responses to adverse factors, and, therefore, to set general requirements to conditions of cultivation. Use of cluster analysis suggests that in the analysis of only quantitative data; define a set of variables used to assess varieties (and the more sampling, the more accurate the clustering will happen, be sure to ascertain the measure of similarity (or difference between objects. It is shown that the identification of diagnostic features, which are subjected to statistical processing, impact the accuracy of the varieties classification. Selection in result of the mono-clusters analysis (variety tea Kolhida; hazelnut Lombardsky red; variety kiwi Monty

  4. Storm Aerosol Environments and Aerosol Sources in Subtropical South America (United States)

    Cancelada, M.; Salio, P. V.; Nesbitt, S. W.


    Several studies have shown a strong interaction in the subtropical area of Southeastern South America (SESA) between deep moist convection and the presence of the South American low level jet (SALLJ), which advects humidity and heat from tropical latitudes creating ideal conditions in the environment for convective activity. Moreover, the SALLJ is considered an important mechanism for transport of gases and particulate matter emitted in tropical South America. Biomass burning season associated with deforestation and land clearing for agricultural use is observed in these regions principally from August to October. Past studies have shown, through modeling and in-situ measurements, an increase in optical depth and Angstrom exponent during SALLJ events. Evidence of an increase in aerosol loading during burning biomass season, along with favorable conditions for deep moist convection activity, supports the hypothesis of an indirect effect from aerosols in convective development in SESA. The objective of this work is to characterize aerosol environments in SESA associated with the presence of mesoscale convective system development. High aerosol concentration events during biomass burning season from 2002 to 2015 were detected using corrected aerosol optical depth (CAOD) with 10-km horizontal resolution from Moderate Resolution Imaging Spectroradiometer (MODIS) Aerosol Products. Environmental variables from NCEP Climate Forecast System Reanalysis (CFSR) were examined to detect SALLJ events and deep moist convection development was observed through infrared channel from GOES. This combination of aerosol data and SALLJ presence determined a data-set for polluted and non-polluted environments. A remarkable correlation between higher values of CAOD in central Argentina and SALLJ was found. A case of study with evidence of SALLJ, high CAOD values and strong convection development was examined. A Weather Research and Forecasting (WRF) simulation has been performed in order

  5. Long-Term Observations of Dust Storms in Sandy Desert Environments (United States)

    Yun, Hye-Won; Kim, Jung-Rack; Choi, Yun-Soo


    Mineral dust occupies the largest portion of atmospheric aerosol. Considering the numerous risks that dust poses for socioeconomic and anthropogenic activities, it is crucial to understand sandy desert environments, which frequently generate dust storms and act as a primary source of atmospheric aerosol. To identify mineral aerosol mechanisms, it is essential to monitor desert environmental factors involving dust storm generation in the long term. In this study, we focused on two major environmental factors: local surface roughness and soil moisture. Since installments of ground observation networks in sandy deserts are unfeasible, remote sensing techniques for mining desert environmental factors were employed. The test area was established within the Badain Jaran and Kubuqi Deserts in Inner Mongolia, China, where significant seasonal aeolian processes emit mineral dust that influences all of East Asia. To trace local surface roughness, we employed a multi-angle imaging spectroradiometer (MISR) image sequence to extract multi-angle viewing (MAV) topographic parameters such as normalized difference angular index, which represents characteristics of the target desert topography. The backscattering coefficient from various space-borne SAR and stereotopography were compared with MAV observations to determine calibrated local surface roughness. Soil moisture extraction techniques from InSAR-phase coherence stacks were developed and compiled with advanced scatterometer (ASCAT) soil moisture data. Combined with metrological information such as the European Centre for Medium-Range Weather Forecasts (ECMWF) ERA interim, correlations between intensity of sand dune activity as a proxy of aeolian processes in desert environments, surface wind conditions, and surface soil moisture were traced. Overall, we have confirmed that tracking sandy desert aeolian environments for long-term observations is feasible with space-borne, multi-sensor observations when combined with

  6. Regime Shift in Sandy Beach Microbial Communities following Deepwater Horizon Oil Spill Remediation Efforts


    Annette Summers Engel; Gupta, Axita A.


    Sandy beaches support a wide variety of underappreciated biodiversity that is critical to coastal ecosystems. Prior to the 2010 Deepwater Horizon oil spill, the diversity and function of supratidal beach sediment microbial communities along Gulf of Mexico coastlines were not well understood. As such, it was unclear if microbial community compositional changes would occur following exposure to beached oil, if indigenous communities could biodegrade oil, or how cleanup efforts, such as sand was...

  7. Self-Reported and FEMA Flood Exposure Assessment after Hurricane Sandy: Association with Mental Health Outcomes. (United States)

    Lieberman-Cribbin, Wil; Liu, Bian; Schneider, Samantha; Schwartz, Rebecca; Taioli, Emanuela


    Hurricane Sandy caused extensive physical and economic damage; the long-term mental health consequences are unknown. Flooding is a central component of hurricane exposure, influencing mental health through multiple pathways that unfold over months after flooding recedes. Here we assess the concordance in self-reported and Federal Emergency Management (FEMA) flood exposure after Hurricane Sandy and determine the associations between flooding and anxiety, depression, and post-traumatic stress disorder (PTSD). Self-reported flood data and mental health symptoms were obtained through validated questionnaires from New York City and Long Island residents (N = 1231) following Sandy. Self-reported flood data was compared to FEMA data obtained from the FEMA Modeling Task Force Hurricane Sandy Impact Analysis. Multivariable logistic regressions were performed to determine the relationship between flooding exposure and mental health outcomes. There were significant discrepancies between self-reported and FEMA flood exposure data. Self-reported dichotomous flooding was positively associated with anxiety (ORadj: 1.5 [95% CI: 1.1-1.9]), depression (ORadj: 1.7 [1.3-2.2]), and PTSD (ORadj: 2.5 [1.8-3.4]), while self-reported continuous flooding was associated with depression (ORadj: 1.1 [1.01-1.12]) and PTSD (ORadj: 1.2 [1.1-1.2]). Models with FEMA dichotomous flooding (ORadj: 2.1 [1.5-2.8]) or FEMA continuous flooding (ORadj: 1.1 [1.1-1.2]) were only significantly associated with PTSD. Associations between mental health and flooding vary according to type of flood exposure measure utilized. Future hurricane preparedness and recovery efforts must integrate micro and macro-level flood exposures in order to accurately determine flood exposure risk during storms and realize the long-term importance of flooding on these three mental health symptoms.

  8. Mycorrhizal population on various cropping systems on sandy soil in dryland area of North Lombok, Indonesia

    Directory of Open Access Journals (Sweden)



    Full Text Available Abstract. Astiko W, Fauzi MT, Sukartono. 2016. Mycorrhizal population on various cropping systems on sandy soil in dryland area of North Lombok, Indonesia. Nusantara Bioscience 8: 66-70. Inoculation of arbuscular mycorrhizal fungi (AMF on maize in sandy soil is expected to have positive implications for the improvement of AMF population and nutrient uptake. However, how many increases in the AMF population and nutrient uptake in the second cycle of a certain cropping system commonly cultivated by the farmers after growing their corn crop have not been examined. Since different cropping systems would indicate different increases in the populations of AMF and nutrient uptake. This study aimed to determine the population AMF and nutrient uptake on the second cropping cycle of corn-based cropping systems which utilized indigenous mycorrhizal fungi on sandy soil in dryland area of North Lombok, West Nusa Tenggara, Indonesia. For that purpose, an experiment was conducted at the Akar-Akar Village in Bayan Sub-district of North Lombok, designed according to the Randomized Complete Block Design, with four replications and six treatments of cropping cycles (P0 = corn-soybean as a control, in which the corn plants were not inoculated with AMF; P1 = corn-soybean, P2 = corn-peanut, P3 = corn-upland rice, P4 = corn-sorghum, and P5 = corn-corn, in which the first cycle corn plants were inoculated with AMF. The results indicated that the mycorrhizal populations (spore number and infection percentage were highest in the second cycle sorghum, achieving 335% and 226% respectively, which were significantly higher than those in the control. Increased uptake of N, P, K and Ca the sorghum plants at 60 DAS of the second cropping cycle reached 200%; 550%; 120% and 490% higher than in the control. The soil used in this experiment is rough-textured (sandy loam, so it is relatively low in water holding capacity and high porosity.

  9. Use of dolomite phosphate rock (DPR) fertilizers to reduce phosphorus leaching from sandy soil. (United States)

    Chen, G C; He, Z L; Stoffella, P J; Yang, X E; Yu, S; Calvert, D


    There is increasing concern over P leaching from sandy soils applied with water-soluble P fertilizers. Laboratory column leaching experiments were conducted to evaluate P leaching from a typical acidic sandy soil in Florida amended with DPR fertilizers developed from dolomite phosphate rock (DPR) and N-Viro soil. Ten leaching events were carried out at an interval of 7 days, with a total leaching volume of 1,183 mm equivalent to the mean annual rainfall of this region during the period of 2001-2003. Leachates were collected and analyzed for total P and inorganic P. Phosphorus in the leachate was dominantly reactive, accounting for 67.7-99.9% of total P leached. Phosphorus leaching loss mainly occurred in the first three leaching events, accounting for 62.0-98.8% of the total P leached over the whole period. The percentage of P leached (in the total P added) from the soil amended with water-soluble P fertilizer was higher than those receiving the DPR fertilizers. The former was up to 96.6%, whereas the latter ranged from 0.3% to 3.8%. These results indicate that the use of N-Viro-based DPR fertilizers can reduce P leaching from sandy soils.

  10. Effect of pore-size distribution on the collapse behaviour of anthropogenic sandy soil deposits

    Directory of Open Access Journals (Sweden)

    Baille Wiebke


    Full Text Available In the former open-pit mines of the Lusatian region in Germany, several liquefaction events have occurred during the recent years in the anthropogenic deposits made of very loose sandy soils. These events are related to the rising ground water table after the stop of controlled ground water lowering. The very loose state is due to the formation of sand aggregates (pseudo-grains during the deposition process. The pseudo-grains enclose larger voids of dimension greater than the single sand grain. Wetting induced collapse of the pseudo-grains is presumed to be one of the possible mechanisms triggering liquefaction. In the present study, the effect of larger voids on the wetting induced deformation behaviour of sandy soils is experimentally investigated by laboratory box tests. The deformation field in the sample during wetting was measured using Digital Image Correlation (DIC technique. The results show that the observed deformations are affected by the pore size distribution, thus the amount of voids between the pseudo-grains (macro-void ratio and the voids inside the pseudo-grains (matrix void ratio. The global void ratio of a sandy soil is not sufficient as single state parameter, but the pore size distribution has to be taken into account, experimentally as well as in modelling.

  11. An observational and modeling study of extratropical transition of Hurricane Sandy in 2012 (United States)

    Fu, Dan; Li, Pengyuan; Fu, Gang


    Around 30 October 2012, Hurricane Sandy made landfall along the New Jersey shoreline after its completion of extratropical transition and transformation into an extratropical cyclone. The strong gale induced a catastrophic storm surge, and caused 72 death and damage of more than 50 billion. In this paper, the evolutionary process and spatial structure of the Hurricane Sandy during its extratropical transition were investigated by using Weather Research and Forecasting (WRF) version 3.3.1 modeling results and National Center for Environmental Prediction (NCEP) Coupled Forecast System model version 2 reanalysis datasets (CFSv2). It is found that during the upper-level trough interaction on 29 October, Sandy gradually fused with a pre-existing mid-latitude low-pressure system, and finished the re-intensification. WRF modeling results showed that the second peak occurred mainly due to the enhanced vertical motion, reduced vertical wind shear as well as the supplement of potential vorticity resulting from trough interaction over the southeast of Great Lakes. The cold continental air from the back of trough was encircled within the warm core system cyclonically, forming the characteristic of warm seclusion.

  12. Tuberculosis control activities before and after Hurricane Sandy--northeast and mid-Atlantic states, 2012. (United States)


    On October 29, 2012, Hurricane Sandy struck the U.S. northeast and mid-Atlantic seaboard; the effects of the storm extended to southeastern and midwestern states and to eastern Canada. At the time, 1,899 residents in the most affected areas were undergoing treatment for tuberculosis (TB) disease or infection. To ascertain the operational abilities of state and local TB programs during and after the storm and to determine whether lessons learned from a previous hurricane were effective in ensuring continuity of TB patient care, CDC interviewed staff members at all of the affected state and city TB control programs, including those in areas with power outages and flooded streets, tunnels, and subway lines. The interviews determined that continuity of care for TB patients in programs affected by Hurricane Sandy was better preserved than it had been during and after Hurricane Katrina in August 2005. This improvement might be attributed to 1) preparedness measures learned from Hurricane Katrina (e.g., preparing line lists of patients, providing patients with as-needed medications, and making back-up copies of patient records in advance of the storm) and 2) less widespread displacement of persons after Hurricane Sandy than occurred after Hurricane Katrina. Maintaining readiness among clinicians and TB control programs to respond to natural disasters remains essential to protecting public health and preserving TB patients' continuity of care.

  13. Long-term Recovery From Hurricane Sandy: Evidence From a Survey in New York City. (United States)

    Petkova, Elisaveta P; Beedasy, Jaishree; Oh, Eun Jeong; Sury, Jonathan J; Sehnert, Erin M; Tsai, Wei-Yann; Reilly, Michael J


    This study aimed to examine a range of factors influencing the long-term recovery of New York City residents affected by Hurricane Sandy. In a series of logistic regressions, we analyzed data from a survey of New York City residents to assess self-reported recovery status from Hurricane Sandy. General health, displacement from home, and household income had substantial influences on recovery. Individuals with excellent or fair health were more likely to have recovered than were individuals with poor health. Those with high and middle income were more likely to have recovered than were those with low income. Also, individuals who had not experienced a decrease in household income following Hurricane Sandy had higher odds of recovery than the odds for those with decreased income. Additionally, displacement from the home decreased the odds of recovery. Individuals who applied for assistance from the Build it Back program and the Federal Emergency Management Agency had lower odds of recovering than did those who did not apply. The study outlines the critical importance of health and socioeconomic factors in long-term disaster recovery and highlights the need for increased consideration of those factors in post-disaster interventions and recovery monitoring. More research is needed to assess the effectiveness of state and federal assistance programs, particularly among disadvantaged populations. (Disaster Med Public Health Preparedness. 2017;page 1 of 4).

  14. Modelling the length of microbiological protection zones around phreatic sandy aquifers in The Netherlands. (United States)

    van der Wielen, P W J J; Blokker, M; Medema, G J


    The aim of the current study was to calculate the size of protection zones around (sub)oxic and anoxic sandy aquifers without confining layers using a virus infection and transport model. The maximum allowable virus infection risk was 10(-4)/person/year at the 95% confidence level. Model results demonstrated that phreatic (sub)oxic sandy aquifers in The Netherlands required protection areas with a residence time of 43-117 d to ensure that the maximum virus infection risk would not be exceeded. This was 0.7-2 x the current guideline of 60d. In contrast, phreatic anoxic sandy aquifers without confining layers needed protection zones of 555-898d to stay below the maximum virus infection risk, 9.5-15 x the current guideline. A sensitivity analysis of the model demonstrated that the calculated protection zone was most sensitive for virus inactivation rate and collision efficiency. Values of both parameters were predicted from values obtained from previously published field and laboratory studies. At present, as it is unknown if these values can also be used at other locations, model results should be interpreted with care.

  15. Vulnerability of Older Adults in Disasters: Emergency Department Utilization by Geriatric Patients After Hurricane Sandy. (United States)

    Malik, Sidrah; Lee, David C; Doran, Kelly M; Grudzen, Corita R; Worthing, Justin; Portelli, Ian; Goldfrank, Lewis R; Smith, Silas W


    Older adults are a potentially medically vulnerable population with increased mortality rates during and after disasters. To evaluate the impact of a natural disaster on this population, we performed a temporal and geospatial analysis of emergency department (ED) use by adults aged 65 years and older in New York City (NYC) following Hurricane Sandy's landfall. We used an all-payer claims database to analyze demographics, insurance status, geographic distribution, and health conditions for post-disaster ED visits among older adults. We compared ED patterns of use in the weeks before and after Hurricane Sandy throughout NYC and the most afflicted evacuation zones. We found significant increases in ED utilization by older adults (and disproportionately higher in those aged ≥85 years) in the 3 weeks after Hurricane Sandy, especially in NYC evacuation zone one. Primary diagnoses with notable increases included dialysis, electrolyte disorders, and prescription refills. Secondary diagnoses highlighted homelessness and care access issues. Older adults display heightened risk for worse health outcomes with increased ED visits after a disaster. Our findings suggest the need for dedicated resources and planning for older adults following a natural disaster by ensuring access to medical facilities, prescriptions, dialysis, and safe housing and by optimizing health care delivery needs to reduce the burden of chronic disease. (Disaster Med Public Health Preparedness. 2017;page 1 of 10).

  16. Hurricane Sandy washover deposits on southern Long Beach Island, New Jersey (United States)

    Bishop, James M.; Richmond, Bruce M.; Zaremba, Nicholas J.; Lunghino, Brent D.; Kane, Haunani H.


    Sedimentologic and topographic data from Hurricane Sandy washover deposits were collected from southern Long Beach Island, New Jersey, in order to document changes to the barrier-island beaches, dunes, and coastal wetlands caused by Hurricane Sandy and subsequent storm events. These data will provide a baseline dataset for use in future coastal change descriptive and predictive studies and assessments. The data presented here were collected as part of the U.S. Geological Survey’s Barrier Island and Estuarine Wetland Physical Change Assessment Project (, which aims to assess ecological and societal vulnerability that results from long- and short-term physical changes to barrier islands and coastal wetlands. This report describes data that were collected in April 2015, approximately 2½ years after Hurricane Sandy’s landfall on October 29, 2012. During the field campaign, washover deposits were photographed and described, and sediment cores, sediment samples, and surface-elevation data were collected. Data collected during this study, including sample locations and elevations, core photographs, computed tomography scans, descriptive core logs, sediment grain-size data, and accompanying Federal Geographic Data Committee metadata, are available in the associated U.S. Geological Survey data release (Bishop and others, 2016;

  17. Historical grassland desertification changes in the Horqin Sandy Land, Northern China (1985-2013). (United States)

    Li, Jinya; Xu, Bin; Yang, Xiuchun; Qin, Zhihao; Zhao, Lina; Jin, Yunxiang; Zhao, Fen; Guo, Jian


    Since rural reforms in the 1980s, both the state and local governments of China have devoted great efforts to combating desertification through a number of eco-environmental restoration campaigns, resulting in burgeoning contention at all levels of government and sparking public concern. Monitoring and accurately assessing the statuses and trends of grassland desertification are important for developing effective restoration strategies. The Horqin Sandy Land (HSL), a very typical desertified grassland (DG) with better hydrothermal conditions among sandy lands in north China, was recently selected (1985-2013) to assess the spatiotemporal dynamic performances of grassland desertification before and after implementing restoration projects. Landsat images (TM/ETM+/OLI), field investigations and expert review were integrated to form a classification scheme for the HSL. Then, spectral mixture analysis and the decision-tree method were used to extract bare-sand ratios and vegetation cover fraction dynamics. A favourable phenomenon of DG was seen to be reversed in an accelerated pace during 2001-2013, despite challenge from both climatic and anthropogenic factors. However, overexploitation of grassland (especially for farming) and ground water for irrigation has led to remarkable decreases in the ground water level in recent decades, which should be highly concerning regarding the formulation of restoration campaigns in the sandy land.

  18. Personality diatheses and Hurricane Sandy: effects on post-disaster depression. (United States)

    Kopala-Sibley, D C; Kotov, R; Bromet, E J; Carlson, G A; Danzig, A P; Black, S R; Klein, D N


    According to diathesis-stress models, personality traits, such as negative emotionality (NE) and positive emotionality (PE), may moderate the effects of stressors on the development of depression. However, relatively little empirical research has directly examined whether NE and PE act as diatheses in the presence of stressful life events, and no research has examined whether they moderate the effect of disaster exposure on depressive symptoms. Hurricane Sandy, the second costliest hurricane in US history, offers a unique opportunity to address these gaps. A total of 318 women completed measures of NE and PE 5 years prior to Hurricane Sandy. They were also assessed for lifetime depressive disorders on two occasions, the latter occurring an average of 1 year before the hurricane. Approximately 8 weeks after the disaster (mean = 8.40, s.d. = 1.48 weeks), participants completed a hurricane stress exposure questionnaire and a measure of current depressive symptoms. Adjusting for lifetime history of depressive disorders, higher levels of stress from Hurricane Sandy predicted elevated levels of depressive symptoms, but only in participants with high levels of NE or low levels of PE. These findings support the role of personality in the development of depression and suggest that personality traits can be useful in identifying those most vulnerable to major stressors, including natural disasters.

  19. Exploring Water Level Sensitivity for Metropolitan New York during Sandy (2012 Using Ensemble Storm Surge Simulations

    Directory of Open Access Journals (Sweden)

    Brian A. Colle


    Full Text Available This paper describes storm surge simulations made for Sandy (2012 for the Metropolitan New York (NYC area using the Advanced Circulation (ADCIRC model forced by the Weather Research and Forecasting (WRF model. The atmospheric forecast uncertainty was quantified using 11-members from an atmospheric Ensemble Kalman Filter (EnKF system. A control WRF member re-initialized every 24 h demonstrated the capability of the WRF-ADCIRC models to realistically simulate the 2.83 m surge and 4.40 m storm tide (surge + astronomical tide above mean lower low water (MLLW for NYC. Starting about four days before landfall, an ensemble of model runs based on the 11 “best” meteorological predictions illustrate how modest changes in the track (20–100 km and winds (3–5 m s−1 of Sandy approaching the New Jersey coast and NYC can lead to relatively large (0.50–1.50 m storm surge variations. The ensemble also illustrates the extreme importance of the timing of landfall relative to local high tide. The observed coastal flooding was not the worst case for this particular event. Had Sandy made landfall at differing times, locations and stages of the tide, peak water levels could have been up to 0.5 m higher than experienced.

  20. Prevalence of Balantidium coli infection in sows in Hunan province, subtropical China. (United States)

    Yin, De-Ming; Lv, Cong-Cong; Tan, Lei; Zhang, Tie-Niu; Yang, Cheng-Zhi; Liu, Yi; Liu, Wei


    Balantidium coli is a cosmopolitan parasitic-opportunistic pathogen that can be found throughout the world. However, little information is available about prevalence of B. coli in pigs in China. In the present study, the prevalence of B. coli in pigs was investigated in Hunan province, subtropical China, between January 2012 and August 2014. A total of 3925 diarrheic fecal samples from nine representative administrative regions in Hunan province, subtropical China, were examined for the presence of B. coli cysts and/or trophozoites using microscopy after sedimentation with water. The overall prevalence of B. coli in pigs was 36.9 % (1450/3925). The present survey revealed high circulation of B. coli in pigs in Hunan province, subtropical China, which poses potential threats to human health. The results of the present investigation have important implications for the control of B. coli infections in pigs in Hunan province, subtropical China. To our knowledge, this is the first comprehensive report of B. coli prevalence in sows in Hunan province, subtropical China.

  1. The status of sandy beach science: Past trends, progress, and possible futures (United States)

    Nel, Ronel; Campbell, Eileen E.; Harris, Linda; Hauser, Lorenz; Schoeman, David S.; McLachlan, Anton; du Preez, Derek R.; Bezuidenhout, Karien; Schlacher, Thomas A.


    Open-ocean sandy beaches are coastal ecosystems with growing relevance in the face of global change. They provide key ecosystem services, such as storm buffering, nutrient cycling, water purification, nursery habitats for resource species, and feeding-breeding habitats for focal species (e.g. endangered sea turtles and shorebirds), and have also become nodes for economic development and cultural use. As a result, beaches face a range of threats, primarily from extractive use, habitat modification and development, sea-level rise and coastal squeeze. Consequently, balancing conservation of the ecosystem and sustainable use of the goods and services is particularly important for sandy shores. Thus, the only way to ensure their protection and continued provision of their valuable services, especially in a period of rapid global change, will be to apply knowledge generated from sound science in beach conservation and management. Here we aim to (1) identify and outline the broad ecological paradigms in sandy beach science; (2) report on a citation analysis of the published literature of the past 63 years (1950-2013) to provide context regarding the topics and location of research, the size and institutional composition of the research teams; and (3) investigate whether beach ecology can and has been incorporated into integrated coastal zone management practices. Past research was framed by specific paradigms (chiefly the Swash Exclusion Hypothesis and derivatives), which can be identified with distinct principles and concepts unique to beaches. Most of the sandy beach literature comes from only a few countries (dominated by USA, South Africa, Brazil and Italy), published by small research teams (institutes. The field has yet to establish large multi-disciplinary teams to undertake rigorous experimental science in order to contribute to general ecological theory. Despite the constraints, beach science is responding to new challenges, with increasing use of the latest

  2. The Department of the Interior Strategic Sciences Group and its Response to Hurricane Sandy (United States)

    Ludwig, K. A.; Machlis, G. E.; Applegate, D.


    This presentation will describe the history, mission, and current activities of the newly formed Department of the Interior (DOI) Strategic Sciences Group (SSG), with a focus on its response to Hurricane Sandy and lessons learned from using scenario building to support decision making. There have been several environmental crises of national significance in recent years, including Hurricane Katrina (2005), large-scale California wildfires (2007-2008), the Deepwater Horizon oil spill (2010), and Hurricane Sandy (2012). Such events are complex because of their impacts on the ecology, economy, and people of the affected locations. In these and other environmental disasters, the DOI has had significant responsibilities to protect people and resources and to engage in emergency response, recovery, and restoration efforts. In recognition of the increasingly critical role of strategic science in responding to such complex events, the DOI established the SSG by Secretarial Order in 2012. Its purpose is to provide the DOI with science-based assessments and interdisciplinary scenarios of environmental crises affecting Departmental resources; rapidly assemble interdisciplinary teams of scientists from government, academia, and non-governmental organizations to conduct such work; and provide results to DOI leadership as usable knowledge to support decision making. March 2013 was the SSG's first deployment since its formation. The SSG's charge was to support DOI's participation on the Hurricane Sandy Rebuilding Task Force by developing scenarios of Hurricane Sandy's environmental, economic, and social consequences in the New York/New Jersey area and potential interventions that could improve regional resilience to future major storms. Over the course of one week, the SSG Sandy team (Operational Group Sandy) identified 13 first-tier consequences and 17 interventions. The SSG briefed DOI leadership, Task Force representatives, and other policy makers in both Washington, DC and

  3. The culture of Tilapia species in tropical and subtropical conditions

    Directory of Open Access Journals (Sweden)

    De Maeseneer, J.


    Full Text Available Although since long known by African fishermen it is only in the last 40 years that Tilapia has been recognized as one of the most promising groups of fish species for culture. The initial successes for culture in Central Africa were followed by several failures mainly because of excessive breeding and early sexual maturity in shallow waterbodies as ponds. From the present knowledge it appears that tilapia has a great future for increasing the productivity in unmanaged environments as man-made lakes and reservoirs primarily destined for the production of hydro-electricity. Careful stocking of paddies and irrigation canals can solve a number of biological problems associated with them and provide an additional though valuable high-protein food source. Great future offers also the culture of tilapia in traditional pond culture especially in polyculture with members of the carp family, mullets and waterfowl in areas of the tropical and subtropical belt. In coastal ponds T, mossambica is a valuable species for sanitary reasons. The culture of tilapia in small farm ponds often meets with failure owing to excessive breeding and stunting unless the all-male technique can be applied through government input and encouragement. As a rule this type of production will be the least attractive. Although Tilapia spp. do not achieve the largest individu al growth their tolerance towards adverse conditions and their acceptance of a wide variety of foodstuffs, primarily waste products from agriculture, their resistance to diseases and (at least in some species their tolerance of crowded environments make them suitable subject for cultures in raceways, circular tanks and cages. Through heavy inputs of water and pelletized feeds nearly incredible annual yields as 2 000 tonnes per ha of water surface (1 and more were realized. This means that this type of production surpasses by far any other known form of animal husbandry but it needs high technological input (thus

  4. Decomposing functional trait associations in a Chinese subtropical forest. (United States)

    Li, Xuefei; Pei, Kequan; Kéry, Marc; Niklaus, Pascal A; Schmid, Bernhard


    Functional traits, properties of organisms correlated with ecological performance, play a central role in plant community assembly and functioning. To some extents, functional traits vary in concert, reflecting fundamental ecological strategies. While "trait syndromes" characteristic of e.g. fast-growing, early-successional vs. competitive, late-successional species are recognized in principle, less is known about the environmental and genetic factors at the source of trait variation and covariation within plant communities. We studied the three leaf traits leaf half-life (LHL), leaf mass per area (LMA) and nitrogen concentration in green leaves (Ngreen) and the wood trait wood density (WD) in 294 individuals belonging to 45 tree or shrub species in a Chinese subtropical forest from September 2006 to January 2009. Using multilevel ANOVA and decomposition of sums of products, we estimated the amount of trait variation and covariation among species (mainly genetic causes), i.e. plant functional type (deciduous vs. evergreen species), growth form (tree vs. shrub species), family/genus/species differences, and within species (mainly environmental causes), i.e. individual and season. For single traits, the variation between functional types and among species within functional types was large, but only LMA and Ngreen varied significantly among families and thus showed phylogenetic signal. Trait variation among individuals within species was small, but large temporal variation due to seasonal effects was found within individuals. We did not find any trait variation related to soil conditions underneath the measured individuals. For pairs of traits, variation between functional types and among species within functional types was large, reflecting a strong evolutionary coordination of the traits, with LMA, LHL and WD being positively correlated among each other and negatively with Ngreen. This integration of traits was consistent with a putative stem-leaf economics spectrum

  5. Observation of new particle formation in subtropical urban environment

    Directory of Open Access Journals (Sweden)

    H. C. Cheung


    Full Text Available The aim of this study was to characterise the new particle formation events in a subtropical urban environment in the Southern Hemisphere. The study measured the number concentration of particles and its size distribution in Brisbane, Australia during 2009. The variation of particle number concentration and nucleation burst events were characterised as well as the particle growth rate which was first reported in urban environment of Australia. The annual average NUFP, NAitken and NNuc were 9.3×103, 3.7×103 and 5.6×103 cm−3, respectively. Weak seasonal variation in number concentration was observed. Local traffic exhaust emissions were a major contributor of the pollution (NUFP observed in morning which was dominated by the Aitken mode particles, while particles formed by secondary formation processes contributed to the particle number concentration during afternoon. Overall, 65 nucleation burst events were identified during the study period. Nucleation burst events were classified into two groups, with and without particles growth after the burst of nucleation mode particles observed. The average particle growth rate of the nucleation events was 4.6 nm h−1 (ranged from 1.79–7.78 nm h−1. Case studies of the nucleation burst events were characterised including (i the nucleation burst with particle growth which is associated with the particle precursor emitted from local traffic exhaust emission, (ii the nucleation burst without particle growth which is due to the transport of industrial emissions from the coast to Brisbane city or other possible sources with unfavourable conditions which suppressed particle growth and (iii interplay between the above two cases which demonstrated the impact of the vehicle and industrial emissions on the variation of particle number concentration and its size

  6. Stormwater quality from extensive green roofs in a subtropical region (United States)

    Onis Pessoa, Jonas; Allasia, Daniel; Tassi, Rutineia; Vaz Viega, Juliana; Fensterseifer, Paula


    Green roofs have increasingly become an integral part of urban environments, mainly due to their aesthetic benefits, thermal comfort and efficiency in controlling excess runoff. However, the effects of this emerging technology in the qualitative characteristics of rainwater is still poorly understood. In this study was evaluated the effect of two different extensive green roofs (EGRs) and a traditional roof built with corrugated fiber cement sheets (control roof) in the quality of rainwater, in a subtropical climate area in the city of Santa Maria, in southern Brazil. The principal variant between the two EGRs were the type of plant species, time since construction, soil depth and the substrate characteristics. During the monitoring period of the experiment, between the months of April and December of 2015 fourteen rainfall events were selected for qualitative analysis of water from the three roofs and directly from rainfall. It was analyzed physical (turbidity, apparent color, true color, electrical conductivity, total solids, dissolved solids, suspended solids and temperature), chemical (pH, phosphate, total nitrogen, nitrate, nitrite, chloride, sulfate, BOD, iron and total hardness), heavy metals (copper, zinc, lead and chromium) and microbiological parameters (total coliforms and E. coli). It was also characterized the substrates used in both extensive green roofs. The results showed that the quality of the water drained from EGR s was directly influenced by their substrates (in turn containing significant levels of nutrients, organic matter and some metals). The passage of rainwater through green roofs and control roof resulted in the elevation of pH, allowing the conversion of the slightly acidic rainfall into basic water. Similarly, on both types of roofs occurred an increase of the values of most of the physical, chemical and microbiological parameters compared to rainwater. This same trend was observed for heavy metals, although with a much smaller degree

  7. Quantifying and Predicting Hydrologic Pathways in Subtropical Depressional Isolated Wetlands (United States)

    Min, J.; Perkins, D. B.; Jawitz, J. W.


    Depressional isolated wetlands exhibit highly transient hydrologic characteristics, which complicates assessment of the hydrologic connection between these systems and uplands. Compared to boundary-fixed water bodies, it is more difficult to measure or estimate each hydrologic pathway because the wetland flooded area changes dramatically in over short time periods. Here, we report a water budget analysis based on routinely collected hydrometeorological monitoring data. Monitoring was carried out over three years in four ditch-linked depressional wetlands of about 1 to 6 ha in the Lake Okeechobee basin, FL. The main objectives of this study were to quantify hydrologic pathways in these subtropical wetlands, which have rarely been tried, and examine how raising ditch outlet elevation would affect the hydrology and phosphorus retention capacity using a mass balance model developed based on the hydrologic quantification. Volume-based water budget components were measured or estimated independently. Rainfall, wetland stage, and upland groundwater level were measured on a daily basis and wetland stage-flooded area relationships were developed from bathymetric surveys. Daily evapotranspiration was estimated using the FAO Penman-Monteith method; ditch outflow was estimated using Manning’s roughness equation; direct runoff was estimated using the NRCS runoff curve number method; indirect runoff, defined as rainfall-induced flow from upland to wetland due to low soil water storage capacity of the unsaturated soil at the wetland-upland border, was estimated using the average capillary rising depth; and groundwater exchange was estimated with average hydraulic conductivity derived using the modified Dupuit equation under a constrained water budget framework. Runoff contributed between 34% and 144% as much water as rainfall at individual wetlands and groundwater inflow was less than 5% of total inflow. Ditch outflow from the systems was highly variable ranging from less than

  8. Serological Survey of Hantavirus in Inhabitants from Tropical and Subtropical Areas of Brazil

    Directory of Open Access Journals (Sweden)

    Felipe Alves Morais


    Full Text Available Brazil has reported more than 1,600 cases of hantavirus cardiopulmonary syndrome (HPS since 1993, with a 39% rate of reported fatalities. Using a recombinant nucleocapsid protein of Araraquara virus, we performed ELISA to detect IgG antibodies against hantavirus in human sera. The aim of this study was to analyze hantavirus antibody levels in inhabitants from a tropical area (Amazon region in Rondônia state and a subtropical (Atlantic Rain Forest region in São Paulo state, Brazil. A total of 1,310 serum samples were obtained between 2003 and 2008 and tested by IgG-ELISA, and 82 samples (6.2%, of which 62 were from the tropical area (5.8% and 20 from the subtropical area (8.3%, tested positive. Higher levels of hantavirus antibody were observed in inhabitants of the populous subtropical areas compared with those from the tropical areas in Brazil.

  9. The post-2002 global surface warming slowdown caused by the subtropical Southern Ocean heating acceleration (United States)

    Oka, A.; Watanabe, M.


    The warming rate of global mean surface temperature slowed down during 1998-2012. Previous studies pointed out role of increasing ocean heat uptake during this global warming slowdown, but its mechanism remains under discussion. Our numerical simulations, in which wind stress anomaly in the equatorial Pacific is imposed from reanalysis data, suggest that subsurface warming in the equatorial Pacific took place during initial phase of the global warming slowdown (1998-2002), as previously reported. It is newly clarified that the Ekman transport from tropics to subtropics is enhanced during the later phase of the slowdown (after 2002) and enhanced subtropical Ekman downwelling causes accelerated heat storage below depth of 700 m in the subtropical Southern Ocean, leading to the post-2002 global warming slowdown. Observational data of ocean temperature also support this scenario. This study provides clear evidence that deeper parts of the Southern Ocean play a critical role in the post-2002 warming slowdown.

  10. Interannual and Decadal Changes in Salinity in the Oceanic Subtropical Gyres (United States)

    Bulusu, Subrahmanyam


    There is evidence that the global water cycle has been undergoing an intensification over several decades as a response to increasing atmospheric temperatures, particularly in regions with skewed evaporation - precipitation (E-P) patterns such as the oceanic subtropical gyres. Moreover, observational data (rain gauges, etc.) are quite sparse over such areas due to the inaccessibility of open ocean regions. In this work, a comparison of observational and model simulations are conducted to highlight the potential applications of satellite derived salinity from NASA Aquarius Salinity mission, NASA Soil Moisture and Ocean Salinity (SMOS), and ESA's Soil Moisture Active Passive (SMAP). We explored spatial and temporal salinity changes (and trends) in surface and subsurface in the oceanic subtropical gyres using Argo floats salinity data, Simple Ocean Data Assimilation (SODA) reanalysis, Estimating the Circulations & Climate of the Ocean GECCO (German ECCO) model simulations, and Hybrid Coordinate Ocean Model (HYCOM). Our results based on SODA reanalysis reveals that a positive rising trend in sea surface salinity in the subtropical gyres emphasizing evidence for decadal intensification in the surface forcing in these regions. Zonal drift in the location of the salinity maximum of the south Pacific, north Atlantic, and south Indian regions implies a change in the mean near-surface currents responsible for advecting high salinity waters into the region. Also we found out that an overall salinity increase within the mixed layer, and a subsurface salinity decrease at depths greater than 200m in the global subtropical gyres over 61 years. We determine that freshwater fluxes at the air-sea interface are the primary drivers of the sea surface salinity (SSS) signature over these open ocean regions by quantifying the advective contribution within the surface layer. This was demonstrated through a mixed layer salinity budget in each subtropical gyre based on the vertically

  11. Carbon dynamics in no-till soil due to the use of industrial organic waste and mineral fertilizer

    National Research Council Canada - National Science Library

    Romaniw, Jucimare; Sá, João Carlos de Moraes; Padilha, Alessandra Aparecida; Ramos, Fabrícia da Silva; Eurich, Guilherme; Bressan, Pamela Thaísa


    ABSTRACTThe use of organic waste from industrial processes in agriculture is a strategy not only for improving soil properties but also for promoting the utilization of recycled nutrients by market...

  12. Creating Carbon Offsets in Agriculture through No-till cultivation: A Meta-Analysis of Costs and Carbon Benefits

    NARCIS (Netherlands)

    Manley, J.; Kooten, van G.C.; Moeltner, K.; Johnson, D.W.


    Carbon terrestrial sinks are often seen as a low-cost alternative to fuel switching and reduced fossil fuel use for lowering atmospheric CO2. To determine whether this is true for agriculture, one meta-regression analysis (52 studies, 536 observations) examines the costs of switching from

  13. Effects of Zero Tillage (No-Till) Conservation Agriculture on soil physical and biological properties and their contributions to sustainability (United States)

    Landers, John N.; Rass, Gerard; de Freitas, Pedro L.; Basch, Gottlieb; González Sanchez, Emilio J.; Tabaglio, Vincenzo; Kassan, Amir; Derpsch, Rolf; Friedrich, Theodor; Giupponi, Luca


    Not cultivating soil, rotating crops over the years, and leaving crop residues on the surface in the practice of zero tillage/conservation agriculture (ZT/CA) reverses the historically accelerating degradation of soil organic matter (SOM) and soil structure, while increasing soil biological activity by a factor of 2 to 4. The results of this are many: (a) not cultivating reduces soil compaction, leaving old root holes to facilitate internal drainage, averts the pulverization of soil aggregates and formation of pans, reduces draft power for planting and gives shelter, winter food and nesting sites for fauna, (b) crop residues on the surface practically eliminate wind and water erosion, reduce soil moisture loss through the mulch effect, slow spring warm-up (possibly offset by a lower specific heat demand with less water retention in surface soil) and act as a reserve of organically-compounded nutrients (as they decompose to humus), (c) more SOM means higher available water and nutrient retention, higher biological activity year round (enhancing biological controls), higher levels of water-stable aggregates and a positive carbon sink in incremental SOM. The positive impacts for society are: (i) more and cheaper food, (ii) reduced flood and drought-induced famine risks, (iii) a positive carbon sink in SOM and possible reductions in NO2 emissions, (iv) cleaner water and greater aquifer recharge due to reduced runoff, (v) cleaner air through effective elimination of dust as a product of cultivation (vi) less water pollution and greater aquifer recharge from reduced rainfall runoff, (vii) farm diesel consumption halved, (viii) reduced demand for (tropical) de-forestation, by permitting crop expansion on steeper lands, (ix) increased wildlife populations (skylarks, plovers, partridge and peccaries) and (x) an improved conservation mindset in farmers. It is notable that, in spite of successful practitioners in all European countries, mainstream adoption is still to come: Europés ZT/CA area is 1.35 million hectares, while the world area is now some 125 million and growing at a rate of 7 million hectares per year. More scientific measurements of the benefits of this system are required, both to assist adoption and to trigger policy measures. In the EEC, CAP reform (greening) needs to consider making environmental services payments for these social benefits since a reduction in single farm payments is ineluctable and carbon footprint reduction is of the essence, in the face of constantly-rising fuel prices and the need to cut GHG emissions. Therefore, as the principal farm tool which offers an effective and immediate solution towards positive changes in soil quality, productivity and sustainability, ZT/CA adoption needs financial incentives, which have high economic and environmental returns to society.

  14. Long-term no-till and stover retention each decrease the global warming potential of irrigated continuous corn (United States)

    Over the last 50 years, the most increase in cultivated land area globally has been due to a doubling of irrigated land. Long-term agronomic management impacts on soil organic carbon (SOC) stocks, soil greenhouse gas (GHG) emis-sions, and global warming potential (GWP) in irrigated systems, however,...

  15. Soil Physical Quality and Soybean Yield as Affected by Chiseling and Subsoiling of a No-Till Soil

    Directory of Open Access Journals (Sweden)

    Luis Alberto Lozano


    Full Text Available ABSTRACT The concept of soil physical quality (SPQ is currently under discussion, and an agreement about which soil physical properties should be included in the SPQ characterization has not been reached. The objectives of this study were to evaluate the ability of SPQ indicators based on static and dynamic soil properties to assess the effects of two loosening treatments (chisel plowing to 0.20 m [ChT] and subsoiling to 0.35 m [DL] on a soil under NT and to compare the performance of static- and dynamic-based SPQ indicators to define soil proper soil conditions for soybean yield. Soil sampling and field determinations were carried out after crop harvest. Soil water retention curve was determined using a tension table, and field infiltration was measured using a tension disc infiltrometer. Most dynamic SPQ indicators (field saturated hydraulic conductivity, K0, effective macroporosity, εma, total connectivity and macroporosity indexes [CwTP and Cwmac] were affected by the studied treatments, and were greater for DL compared to NT and ChT (K0 values were 2.17, 2.55, and 4.37 cm h-1 for NT, ChT, and DL, respectively. However, static SPQ indicators (calculated from the water retention curve were not capable of distinguishing effects among treatments. Crop yield was significantly lower for the DL treatment (NT: 2,400 kg ha-1; ChT: 2,358 kg ha-1; and DL: 2,105 kg ha1, in agreement with significantly higher values of the dynamic SPQ indicators, K0, εma, CwTP, and Cwmac, in this treatment. The results support the idea that SPQ indicators based on static properties are not capable of distinguishing tillage effects and predicting crop yield, whereas dynamic SPQ indicators are useful for distinguishing tillage effects and can explain differences in crop yield when used together with information on weather conditions. However, future studies, monitoring years with different weather conditions, would be useful for increasing knowledge on this topic.

  16. Irrigation and cultivar effects in no-till, cover crop, and conventional tillage systems in Arkansas Cotton. (United States)

    This field experiment was conducted in association with a long term tillage study established in fall 2007 at the Judd Hill Foundation Research Farm in Northeast Arkansas to assess agronomic and environmental impacts of conservation tillage systems. In component studies in 2016 we evaluated performa...

  17. Carbon Balance of No-Till Soybean with Winter Wheat Cover Crop in the Southeastern United States (United States)

    Gebremedhin, M. T.; Loescher, H.; Tsegaye, T.


    The southeast is an important agricultural region in the U.S. and key component of the continental carbon budget. Croplands in the region store a substantial amount of soil organic carbon (C). However, their C sink status may be altered under the projected changes in precipitation pattern for the region. The study was conducted at Winfred Thomas Agricultural Research Station, Hazel Green, Alabama (2007-2009). We investigated the seasonal and interannual variation in net ecosystem exchange of CO2 (NEE) of winter wheat (Tricticum aestivum) and soybean (Glycine max) using the eddy covariance method. Annual C balance ranged from the highest source in 2007 (NEE = 100 g C m-2 y-1) to sink (-20 g C m-2 y-1) in 2009. Annual ecosystem respiration (Re) ranged between 750 and 1013 g C m-2 y-1, while gross ecosystem productivity (GEP) was 650-1034 g C m-2 y-1. Seasonal NEE for soybean ranged between 42 and -66 g C m-2. Stronger winter wheat NEE (-80.0, -80.4, -40.0 g C m-2 for 2007, 2008 and 2009) than soybean suggested the importance of winter C uptakes offsetting summer C losses. Re was controlled by air temperature, and it varied between 286 and 542 g C m-2 for soybean, and between 160 and 313 g C m-2 for winter wheat. Precipitation was key determinant of C balance implying larger C release during drought periods. During fallow months, the site was C source. If we include removal of grain off site, this system could become a C source under all conditions.

  18. In situ validation of fungal N translocation to cereal rye mulches under no-till soybean production (United States)

    Grass cover crop shoots can be used as a mulch to suppress weeds. Physical control (light and temperature) of weeds appear to be the primary mechanism with chemical control (allelopathy) playing a smaller role. However, limitations of nitrogen availability to weeds in a soybean crop have been identi...

  19. Crop rotation and seasonal effects on fatty acid profiles of neutral and phospholipids extracted from no-till agricultural soils

    DEFF Research Database (Denmark)

    Ferrari, Alejandro E.; Ravnskov, Sabine; Larsen, John


    . Highrotation (HR) management consisted in maize–wheat–soybean intense rotation including cover crops.Low rotation (LR) management trend to soybean monocultures. Soils from nearby naturalenvironments (NEs) were used as references. Fatty acids concentration in soils (nmol/g) decreased c.a.50% from summer...

  20. Cultivares de soja sob plantio direto em Latossolo Vermelho compactado = Soybean cultivars under no-till on a compacted oxisol

    Directory of Open Access Journals (Sweden)

    Neyde Fabíola Balarezo Giarola


    Full Text Available O processo de compactação pode modificar os atributos físicos do solo a ponto de limitar o potencial genético de desenvolvimento de culturas agrícolas ou de cultivares mais sensíveis. O objetivo deste trabalho foi avaliar, em Latossolo Vermelho Eutroférrico típico, a resposta de parâmetros de produção de cultivares de soja (Glycine max L. Merrill e atributos físicos do solo ao sistema plantio direto em condições de lavoura e com compactação adicional. O estudo foi conduzido na C-Vale Cooperativa Agroindustrial, em Palotina, Estado do Paraná. Foram avaliados dois tratamentos de solo: sistema plantio direto sem compactação adicional (SPD-C0 e sistema plantio direto com compactação adicional (PD-C1, e cinco cultivares de soja: (1 Coodetec 204, (2 Coodetec 215, (3 Monsoy 5942,(4 Embrapa 48 e (5 Spring. Adotou-se o delineamento experimental inteiramente casualizado em esquema fatorial 5 X 2. Os atributos de solo avaliados foram: densidade do solo, porosidade total, macro e microporosidade. Nas plantas, foram avaliadas as seguintes variáveis: fitomassa seca, altura de plantas, altura de inserção da primeira vagem, massa demil grãos e produtividade. Os resultados demonstraram que as variáveis de produção das cultivares de soja não foram influenciados pelos diferentes níveis de compactação do solo, e as diferenças observadas se deveram às características das próprias cultivares.The compaction process can promote changes in the physical attributes of soil, to the point of limiting the genetic potential for the development of more sensitive agricultural crops or cultivars. Thegoal of this study was to evaluate, on a clayed Red Latosol (Oxisol, the response of production parameters of different varieties of soybean (Glycine max and physical attributes of soil under tillage farming, and with additional compression. The study was conducted at C-Valley Agroindustrial Cooperative, in Palotina (Paraná State. Two treatments of soil were evaluated: no-tillage without additional compaction (PD-C0 and no-tillage with additional compaction (PD-C1, and five varieties of soybeans: (1 Coodetec 204, (2 Coodetec 215, (3 Monsoy 5942, (4 Embrapa 48 and (5 Spring. A completely randomized experimental design in a 5 x 2 factorial scheme was adopted. The attributes of soil evaluated were: bulk density, totalporosity, macro- and microporosity. In the plants, the following parameters were assessed: harvesting dates, plant height, height of insertion of the first pod, mass of one thousand grains and productivity. The results showed that the parameters for the production of soybean cultivars were not influenced by the different levels of soil compaction, and the differences observed were due to the characteristics of the cultivars themselves.

  1. The Storm Surge and Sub-Grid Inundation Modeling in New York City during Hurricane Sandy

    Directory of Open Access Journals (Sweden)

    Harry V. Wang


    Full Text Available Hurricane Sandy inflicted heavy damage in New York City and the New Jersey coast as the second costliest storm in history. A large-scale, unstructured grid storm tide model, Semi-implicit Eulerian Lagrangian Finite Element (SELFE, was used to hindcast water level variation during Hurricane Sandy in the mid-Atlantic portion of the U.S. East Coast. The model was forced by eight tidal constituents at the model’s open boundary, 1500 km away from the coast, and the wind and pressure fields from atmospheric model Regional Atmospheric Modeling System (RAMS provided by Weatherflow Inc. The comparisons of the modeled storm tide with the NOAA gauge stations from Montauk, NY, Long Island Sound, encompassing New York Harbor, Atlantic City, NJ, to Duck, NC, were in good agreement, with an overall root mean square error and relative error in the order of 15–20 cm and 5%–7%, respectively. Furthermore, using large-scale model outputs as the boundary conditions, a separate sub-grid model that incorporates LIDAR data for the major portion of the New York City was also set up to investigate the detailed inundation process. The model results compared favorably with USGS’ Hurricane Sandy Mapper database in terms of its timing, local inundation area, and the depth of the flooding water. The street-level inundation with water bypassing the city building was created and the maximum extent of horizontal inundation was calculated, which was within 30 m of the data-derived estimate by USGS.

  2. Estimation of nitrogen pools in irrigated potato production on sandy soil using the model SUBSTOR.

    Directory of Open Access Journals (Sweden)

    Rishi Prasad

    Full Text Available Recent increases in nitrate concentrations in the Suwannee River and associated springs in northern Florida have raised concerns over the contributions of non-point sources. The Middle Suwannee River Basin (MSRB is of special concern because of prevalent karst topography, unconfined aquifers and sandy soils which increase vulnerability of the ground water contamination from agricultural operations--a billion dollar industry in this region. Potato (Solanum tuberosum L. production poses a challenge in the area due to the shallow root system of potato plants, and low water and nutrient holding capacity of the sandy soils. A four-year monitoring study for potato production on sandy soil was conducted on a commercial farm located in the MSRB to identify major nitrogen (N loss pathways and determine their contribution to the total environmental N load, using a partial N budget approach and the potato model SUBSTOR. Model simulated environmental N loading rates were found to lie within one standard deviation of the observed values and identified leaching loss of N as the major sink representing 25 to 38% (or 85 to 138 kg ha(-1 N of the total input N (310 to 349 kg ha(-1 N. The crop residues left in the field after tuber harvest represented a significant amount of N (64 to 110 kg ha(-1 N and posed potential for indirect leaching loss of N upon their mineralization and the absence of subsequent cover crops. Typically, two months of fallow period exits between harvest of tubers and planting of the fall row crop (silage corn. The fallow period is characterized by summer rains which pose a threat to N released from rapidly mineralizing potato vines. Strategies to reduce N loading into the groundwater from potato production must focus on development and adoption of best management practices aimed on reducing direct as well as indirect N leaching losses.

  3. Estimation of nitrogen pools in irrigated potato production on sandy soil using the model SUBSTOR. (United States)

    Prasad, Rishi; Hochmuth, George J; Boote, Kenneth J


    Recent increases in nitrate concentrations in the Suwannee River and associated springs in northern Florida have raised concerns over the contributions of non-point sources. The Middle Suwannee River Basin (MSRB) is of special concern because of prevalent karst topography, unconfined aquifers and sandy soils which increase vulnerability of the ground water contamination from agricultural operations--a billion dollar industry in this region. Potato (Solanum tuberosum L.) production poses a challenge in the area due to the shallow root system of potato plants, and low water and nutrient holding capacity of the sandy soils. A four-year monitoring study for potato production on sandy soil was conducted on a commercial farm located in the MSRB to identify major nitrogen (N) loss pathways and determine their contribution to the total environmental N load, using a partial N budget approach and the potato model SUBSTOR. Model simulated environmental N loading rates were found to lie within one standard deviation of the observed values and identified leaching loss of N as the major sink representing 25 to 38% (or 85 to 138 kg ha(-1) N) of the total input N (310 to 349 kg ha(-1) N). The crop residues left in the field after tuber harvest represented a significant amount of N (64 to 110 kg ha(-1) N) and posed potential for indirect leaching loss of N upon their mineralization and the absence of subsequent cover crops. Typically, two months of fallow period exits between harvest of tubers and planting of the fall row crop (silage corn). The fallow period is characterized by summer rains which pose a threat to N released from rapidly mineralizing potato vines. Strategies to reduce N loading into the groundwater from potato production must focus on development and adoption of best management practices aimed on reducing direct as well as indirect N leaching losses.

  4. Human recreation alters behaviour profiles of non-breeding birds on open-coast sandy shores (United States)

    Schlacher, Thomas A.; Nielsen, Tara; Weston, Michael A.


    Sandy beaches are primarily valued for their amenity and property values rather than for their ecological functions and properties. Some human usage of beaches potentially conflicts with the conservation and management of wildlife, such as beach-dwelling birds, on sandy shorelines. Because responses by birds to environmental change, including disturbance by humans, often involve behaviours that carry fitness costs, we quantify behaviour profiles of birds in relation to human occurrence along 200 km of sandy shoreline in Eastern Australia, including the large conservation area of Fraser Island. Disturbance to birds on these shores was considerable: 1) birds encountered motorized vehicles (cars, trucks, buses etc.) during 80% of focal bird observation bouts, 2) birds were flushed in over half (up to 86% in individual species) of all bouts, and 3) individuals spent, on average, one-third of their time on disturbance-related behaviours; this was particularly prevalent for Crested Terns (Thalasseus bergii) which were alert 42% of the time and spent 12% of their time escaping from human stimuli. Overall, this study demonstrated that motorized traffic is the prime agent of disturbance to birds on these beaches, resulting in frequent and time-consuming escape behaviours. These findings also emphasize that management of vehicle-based recreation on beaches needs to be re-aligned to meet conservation requirements in addition to providing leisure opportunities in National Parks and beyond; we identify some salient issue for this development: a) encouragement of social norms that promote environmentally benign beach use not involving motor vehicles, b) creation of spatial refuges for beach wildlife from traffic and other non-compatible uses, and c) investment in developing complementary management actions such as effective set-back distances.

  5. Estimation of Variability Characteristics of Regional Drought during 1964–2013 in Horqin Sandy Land, China

    Directory of Open Access Journals (Sweden)

    Yongfang Wang


    Full Text Available Drought has an important influence on the hydrological cycle, ecological system, industrial and agricultural production, and social life. Based on the different time scales of characteristics of drought variability, the standardized precipitation evapotranspiration index (SPEI, a multi-timescale index with consideration of evaporation, was used in this study to estimate the spatial and temporal variability characteristics of drought. Climatic data from 15 meteorological stations across Horqin Sandy Land during 1964–2013 were used to calculate the SPEI of 1, 3, 6, and 12 months. In order to examine the relationship between droughts and other variables, 10 extreme climate indices were calculated based on the daily precipitation and maximum/mean/minimum temperature data of 15 meteorological stations, and linkages between SPEI-12 and atmosphere indices were established using by the cross wavelet transform method. The results indicated that the climate of Horqin Sandy Land had a tendency towards drought conditions, which is particularly apparent from the year 2000 onwards. During the study period, drought events were frequent in the region. Mild drought occurred in a quarter of the month, with that of moderate, severe, and extreme drought accounting for 0.11, 0.05, and 0.02 of the total months. The spatial trend of multi-timescale drought revealed that there was an increase in the severity of drought throughout Horqin Sandy Land, among which the magnitude in southern parts was larger than that of northern parts. The results also showed that the short time scale drought negatively correlated with precipitation extremes and positively correlated with temperature extremes. Furthermore, the long time scale drought (SPEI-12 was associated with atmosphere indices. Significant resonance periods were found between El Nino southern oscillation (ENSO, the East Asian summer monsoon index (EASMI, and SPEI-12.

  6. Influence of Particle Shape on Drag Coefficient for Commonly Occuring Sandy Particles in Coastal Areas

    Directory of Open Access Journals (Sweden)

    Chitra Arora


    Full Text Available A well defined relationship connecting settling velocity with sediment geometry and ambient properties is an essential pre-requisite for coastal and hydraulic engineering studies. An established relationship for settling velocity of sandy particles assuming spherical shape geometry is available in the literature. In reality, the sediment particles need not be spherical at all times, which influences settling velocity that is strongly biased to the drag coefficient. Based on quantitative comparison with measured data collected at Oahu Islands located in the Hawaiian archipelago, USA this work provides a relationship between drag coefficient and particle shape factor for sand grains viz; sand, sandy loam and fine sandy loam typically found in coastal environment (typical size ranges from 0.05 to 2.0 mm. The particle Reynolds number and shape factor are evaluated for each grain. The drag coefficient evaluated as function of nominal diameter and Reynolds number show a positive correlation over a wide range of shape factors used in this study. A comprehensive correlation has been developed of the drag coefficient for non-spherical particles as a function of Reynolds number and particle shape. Further a regression analysis was performed on the functional dependence of drag coefficient on particle shape. Based on this study, it could be advocated the validity of Krumbien shape factor holds well for the above characterized grain size and various particle shapes considered. Hence, the settling velocity of particles has a functional dependence on estimated drag coefficient with important implications for modeling sediment transport and swash zone hydrodynamics.

  7. Throughfall patterns of a Subtropical Atlantic Forest in Brazil (United States)

    Macedo Sá, João Henrique; Borges Chaffe, Pedro Luiz; Yuimi de Oliveira, Debora; Nery Giglio, Joana; Kobiyama, Masato


    The interception process is responsible for the spatial and temporal redistribution of the precipitation that reaches the ground. This process is important especially in forested areas since it influences recycling of moisture from the air and also the amount of water that effectively reaches the ground. The contact of the precipitation with the canopy influences on the water quality, increasing the concentration of various nutrients in the throughfall (Tf) and stemflow (Sf). Brazil, only about 8% of the original Atlantic Forest cover remains. That is an important biome and little is known about the characteristics of rainfall interception of this forest. The total interception loss in forested areas is usually formulated as the gross precipitation (P) minus the sum of the throughfall (Tf) and the stemflow (Sf). The stems characteristics influence on Sf, meanwhile, the value of Tf strongly depends on the canopy and leaf structures. Because of the complex structure of the canopy, these characteristics are usually expressed by the simpler Leaf Area Index (LAI) or the Canopy Cover Fraction (CCF). The Araponga river experimental catchment (ARA) with 5.3 ha is on the northern plateau of Santa Catarina State, southern Brazil. It is an area completely covered by secondary subtropical Atlantic Forest, the regional climate is the Köppen Cfb type, i.e., temperate climate without dry season and with warm summer (the mean temperature of the hottest month is always under 22°C). The objectives of the present study were (i) to evaluate the spatial and temporal variation of canopy cover; (ii) to influence of the interception process on the precipitation quality; and (iii) to explore the relation between canopy cover and throughfall. Inside the catchment, 9 Tf gauges were installed 40 cm above the soil surface in order to include the interception by shrub. 28 hand-made gauges were installed on a circular area of 3 m radius to analyze the spatial variability of throughfall. During

  8. Influence of manganese fertilizer on efficiency of grapes on sandy soils of the Chechen Republic

    Directory of Open Access Journals (Sweden)

    Batukaev A.A.


    Full Text Available As a result of the studies, there has been obtained new information about the manganese influence on productivity of grape plantations, on sandy soils of the Chechen Republic. Manganese fertilizing of 4 kg active ingredient per 1 ha, against the background of nitrogen 90 kg, phosphorus 90 kg and potassium 90 kg/ha, made it into a phase of grape sap flow, which contributes to higher yields, increase of the sugar content of the berries and a significant decrease in juice acidity, in comparison with other options.

  9. Superstorm Sandy marine debris wash-ups on Long Island - What happened to them? (United States)

    Swanson, R Lawrence; Lwiza, Kamazima; Willig, Kaitlin; Morris, Kaitlin


    Superstorm Sandy generated huge quantities of debris in the Long Island, NY coastal zone. However, little appears to have been washed offshore to eventually be returned to Long Island's beaches as marine debris wash-ups. Information for our analysis includes debris collection statistics, very high resolution satellite images, along with wind and sea level data. Rigorous debris collection efforts along with meteorological conditions following the storm appear to have reduced the likelihood of debris wash-ups. Copyright © 2016 Elsevier Ltd. All rights reserved.

  10. Promoting Community Preparedness and Resilience: A Latino Immigrant Community-Driven Project Following Hurricane Sandy. (United States)

    Cuervo, Isabel; Leopold, Les; Baron, Sherry


    As community residents and recovery workers, Latino immigrants play important roles after disasters, yet are rarely included in preparedness planning. A community-university-labor union partnership created a demonstration project after Hurricane Sandy to strengthen connections to disaster preparedness systems to increase community resilience among Latino immigrant communities in New York and New Jersey. Building ongoing ties that connect workers and community-based organizations with local disaster preparedness systems provided mutual benefits to disaster planners and local immigrant communities, and also had an impact on national disaster-related initiatives.

  11. Assessment of physical and chemical indicators of sandy soil quality for sustainable crop production (United States)

    Lipiec, Jerzy; Usowicz, Boguslaw


    Sandy soils are used in agriculture in many regions of the world. The share of sandy soils in Poland is about 55%. The aim of this study was to assess spatial variability of soil physical and chemical properties affecting soil quality and crop yields in the scale of field (40 x 600 m) during three years of different weather conditions. The experimental field was located on the post glacial and acidified sandy deposits of low productivity (Szaniawy, Podlasie Region, Poland). Physical soil quality indicators included: content of sand, silt, clay and water, bulk density and those chemical: organic carbon, cation exchange capacity, acidity (pH). Measurements of the most soil properties were done at spring and summer each year in topsoil and subsoil layer in 150 points. Crop yields were evaluated in places close to measuring points of the soil properties. Basic statistics including mean, standard deviation, skewness, kurtosis minimal, maximal and correlations between the soil properties and crop yields were calculated. Analysis of spatial dependence and distribution for each property was performed using geostatistical methods. Mathematical functions were fitted to the experimentally derived semivariograms that were used for mapping the soil properties and crop yield by kriging. The results showed that the largest variations had clay content (CV 67%) and the lowest: sand content (5%). The crop yield was most negatively correlated with sand content and most positively with soil water content and cation exchange capacity. In general the exponential semivariogram models fairly good matched to empirical data. The range of semivariogram models of the measured indicators varied from 14 m to 250 m indicate high and moderate spatial variability. The values of the nugget-to-sill+nugget ratios showed that most of the soil properties and crop yields exhibited strong and moderate spatial dependency. The kriging maps allowed identification of low yielding sub-field areas that

  12. Storm influence on the burial of objects in a shallow sandy shelf environment


    Papili, S.; T. Wever; Dupont, Y.; Van Lancker, V.


    For rapid assessments of occurrences of sea mines or objects, and probability modelling of object burial mechanisms, knowledge is needed on sediment processes under a variety of hydro meteorological conditions. One approach is to use test mines that record burial mechanisms over longer time periods.A Burial Recording Mine (BRM) was deployed in the Belgian part of the North Sea, in water depths of 7 to 12 m. The area is predominantly sandy, with a continuous spectrum of small- to medium and la...

  13. Compost amendment of sandy soil affects soil properties and greenhouse tomato productivity

    DEFF Research Database (Denmark)

    Arthur, Emmanuel; Cornelis, W.; Razzaghi, Fatemeh


    Sandy soils, with low productivity, could be improved by compost application to sustain crop production. This study aimed to examine the effect of three compost types (vegetable, fruit and yard waste compost, garden waste compost, and spent mushroom compost) on basic properties of a loamy sand...... and significantly decreased bulk density, with no effect on plant available water compared to the control. Fresh and dry fruit weights were significantly increased after compost addition. Plant height, leaf number, stem diameter, and total biomass did not significantly improve after compost addition. Spent mushroom...

  14. Residents’ Experiences of Privacy and Comfort in Multi-Storey Apartment Dwellings in Subtropical Brisbane

    Directory of Open Access Journals (Sweden)

    Rosemary Kennedy


    Full Text Available Dwellings in multi-storey apartment buildings (MSAB are predicted to increase dramatically as a proportion of housing stock in subtropical cities over coming decades. The problem of designing comfortable and healthy high-density residential environments and minimising energy consumption must be addressed urgently in subtropical cities globally. This paper explores private residents’ experiences of privacy and comfort and their perceptions of how well their apartment dwelling modulated the external environment in subtropical conditions through analysis of 636 survey responses and 24 interviews with residents of MSAB in inner urban neighbourhoods of Brisbane, Australia. The findings show that the availability of natural ventilation and outdoor private living spaces play important roles in resident perceptions of liveability in the subtropics where the climate is conducive to year round “outdoor living”. Residents valued choice with regard to climate control methods in their apartments. They overwhelmingly preferred natural ventilation to manage thermal comfort, and turned to the air-conditioner for limited periods, particularly when external conditions were too noisy. These findings provide a unique evidence base for reducing the environmental impact of MSAB and increasing the acceptability of apartment living, through incorporating residential attributes positioned around climate-responsive architecture.

  15. Atlanta ariejansseni, a new species of shelled heteropod from the Southern Subtropical Convergence Zone (Gastropoda, Pterotracheoidea)

    NARCIS (Netherlands)

    Wall-Palmer, D.; Burridge, A.K.; Peijnenburg, K.T.C.A.


    The Atlantidae (shelled heteropods) is a family of microscopic aragonite shelled holoplanktonic gastropods with a wide biogeographical distribution in tropical, sub-tropical and temperate waters. The aragonite shell and surface ocean habitat of the atlantids makes them particularly susceptible to

  16. Precipitation controls on nutrient budgets in subtropical and tropical forests and the implications under changing climate (United States)

    Chang, Chung-Te; Wang, Lih-Jih; Huang, Chuan, Jr.; Liu, Chiung-Pin; Wang, Chiao-Ping; Lin, Neng-Huei; Wang, Lixin; Lin, Teng-Chiu


    Biological, geological and hydrological drivers collectively control forest biogeochemical cycling. However, based on a close examination of recent literature, we argue that the role of hydrological control particularly precipitation on nutrient budgets is significantly underestimated in subtropical and tropical forests, hindering our predictions of future forest nutrient status under a changing climate in these systems. To test this hypothesis, we analyzed two decades of monthly nutrient input and output data in precipitation and streamwater from a subtropical forested watershed in Taiwan, one of the few sites that has long-term nutrient input-output data in the tropics and subtropics. The results showed that monthly input and output of all ions and budgets (output - input) of most ions were positively correlated with precipitation quantity and there was a surprisingly greater net ion export during the wet growing season, indicating strong precipitation control on the nutrient budget. The strong precipitation control is also supported by the divergence of acidic precipitation and near neutral acidity of streamwater, with the former being independent from precipitation quantity but the latter being positively related to precipitation quantity. An additional synthesis of annual precipitation quantity and nutrient budgets of 32 forests across the globe showed a strong correlation between precipitation quantity and nutrient output-input budget, indicating that strong precipitation control is ubiquitous at the global scale and is particularly important in the humid tropical and subtropical forests. Our results imply that climate change could directly affect ecosystem nutrient cycling in the tropics through changes in precipitation pattern and amount.

  17. Variations of Soil Microbial Community Structures Beneath Broadleaved Forest Trees in Temperate and Subtropical Climate Zones. (United States)

    Yang, Sihang; Zhang, Yuguang; Cong, Jing; Wang, Mengmeng; Zhao, Mengxin; Lu, Hui; Xie, Changyi; Yang, Caiyun; Yuan, Tong; Li, Diqiang; Zhou, Jizhong; Gu, Baohua; Yang, Yunfeng


    Global warming has shifted climate zones poleward or upward. However, understanding the responses and mechanism of microbial community structure and functions relevant to natural climate zone succession is challenged by the high complexity of microbial communities. Here, we examined soil microbial community in three broadleaved forests located in the Wulu Mountain (WLM, temperate climate), Funiu Mountain (FNM, at the border of temperate and subtropical climate zones), or Shennongjia Mountain (SNJ, subtropical climate). Although plant species richness decreased with latitudes, the microbial taxonomic α-diversity increased with latitudes, concomitant with increases in soil total and available nitrogen and phosphorus contents. Phylogenetic NRI (Net Relatedness Index) values increased from -0.718 in temperate zone (WLM) to 1.042 in subtropical zone (SNJ), showing a shift from over dispersion to clustering likely caused by environmental filtering such as low pH and nutrients. Similarly, taxonomy-based association networks of subtropical forest samples were larger and tighter, suggesting clustering. In contrast, functional α-diversity was similar among three forests, but functional gene networks of the FNM forest significantly (P climate zones. Using a strategy of space-for-time substitution, we predict that poleward climate range shift will lead to decreased microbial taxonomic α-diversities in broadleaved forest.

  18. Stability and activity of anaerobic sludge from UASB reactors treating sewage in subtropical regions

    NARCIS (Netherlands)

    Seghezzo, L.; Cuevas, C.M.; Trupiano, A.P.; Guerra, R.G.; Gonzalez, S.M.; Zeeman, G.; Lettinga, G.


    The production of small amounts of well-stabilized biological sludge is one of the main advantages of upflow anaerobic sludge bed (UASB) reactors over aerobic wastewater treatment systems. In this work, sludge produced in three pilot-scale UASB reactors used to treat sewage under subtropical

  19. Continuous growth of the giant grass Zizaniopsis bonariensis in subtropical wetlands

    NARCIS (Netherlands)

    Finkler Ferreira, T.; Nes, van E.H.; Motta Marques, da D.


    1. Zizaniopsis bonariensis (giant grass) is an emergent macrophyte species endemic to subtropical wetlands in Brazil, Argentina, Paraguay and Uruguay. In this study, we show the effects of its continuous clonal reproduction and its 'phalanx' growth strategy in the Taim Wetland (southern Brazil). 2.

  20. Modelling spatial heterogeneity of phytoplankton in Lake Mangueira, a large shallow subtropical lake in South Brazil

    NARCIS (Netherlands)

    Fragoso, C.R.; Motta Marques, D.M.L.; Collischonn, W.; Tucci, C.E.M.; Nes, van E.H.


    We present a model describing phytoplankton growth in Lake Mangueira, a large subtropical lake in the Taim Hydrological System in South Brazil (817 km2, average depth 2 m). The horizontal 2D model consists of three modules: (a) a detailed hydrodynamic module for shallow water, which deals with

  1. Potential for biotic resistance from herbivores to tropical and subtropical plant invasions in aquatic ecosystems

    NARCIS (Netherlands)

    Petruzella, A.; Grutters, B.M.C.; Thomaz, S.M.; Bakker, E.S.


    Invasions of tropical and subtropical aquatic plants threaten biodiversity and cause ecological and economic impacts worldwide. An urgent question is whether native herbivores are able to inhibit the spread of these alien species thus providing biotic resistance. The potential for biotic resistance

  2. Diurnal ozone cycle in the tropical and subtropical marine boundary layer

    NARCIS (Netherlands)

    Laat, A.T.J. de; Lelieveld, J.


    A conceptual analysis of diurnal ozone (O3 ) changes in the marine boundary layer (MBL) is presented. Such changes are most pronounced downwind of O3 sources in tropical and subtropical latitudes, and during summer at higher latitudes. Previously, it has been assumed that daytime photochemical O3

  3. Geomorphology, disturbance, and the soil and vegetation of two subtropical wet steepland watersheds of Puerto Rico. (United States)

    Ariel E. Lugo F.N. Scatena


    Relationships between landforms, soil nutrients, forest structure, and the relative importance of different disturbances were quantified in two subtropical wet steepland watersheds in Puerto Rico. Ridges had fewer landslides and treefall gaps, more above-ground biomass, older aged stands, and greater species richness than other landscape positions. Ridge soils had...

  4. Seasonal influenza vaccine policy, use and effectiveness in the tropics and subtropics - a systematic literature review

    NARCIS (Netherlands)

    Hirve, S.; Lambach, P.; Paget, J.; Vandemaele, K.; Fitzner, J.; Zhang, W.


    AIM: The evidence needed for tropical countries to take informed decisions on influenza vaccination is scarce. This article reviews policy, availability, use and effectiveness of seasonal influenza vaccine in tropical and subtropical countries. METHOD: Global health databases were searched in three

  5. Individual size but not additional nitrogen regulates tree carbon sequestration in a subtropical forest (United States)

    Wu, Jianping; Duan, Honglang; Liu, Wenfei; Wei, Xiaohua; Liao, Yingchun; Fan, Houbao


    Recent studies have indicated that tree carbon accumulation in subtropical forests has been negatively affected by global change phenomena such as warming and drought. However, the long-term effect of nitrogen addition on plant carbon storage remains poorly understood in these regions. In this study, we conducted a 10-year field experiment examining the effect of experimental N addition on plant growth and carbon storage in a subtropical Chinese fir forest. The N levels were 0 (control), 60, 120, and 240 kg ha-1 yr-1, and the N effects on tree carbon were divided into stand and individual levels. The results indicated that tree carbon storage at the stand scale was not affected by long-term N addition in the subtropical forest. By contrast, significant impacts of different tree size classes on carbon sequestration were found under different N treatments, which indicated that the amount of plant carbon sequestration was significantly enhanced with tree size class. Our findings highlight the importance of community structure and growth characteristics in Chinese fir forests, in which individual size but not additional N regulates tree carbon sequestration in this subtropical forest.

  6. Analyzing the efficacy of subtropical urban forests in offsetting carbon emissions from cities (United States)

    Francisco Escobedo; Sebastian Varela; Min Zhao; John E. Wagner; Wayne Zipperer


    Urban forest management and policies have been promoted as a tool to mitigate carbon dioxide (CO2) emissions. This study used existing CO2 reduction measures from subtropical Miami-Dade and Gainesville, USA and modeled carbon storage and sequestration by trees to analyze policies that use urban forests to offset carbon emissions. Field data were analyzed, modeled, and...

  7. Experimental evidence for a phylogenetic Janzen-Connell effect in a subtropical forest

    NARCIS (Netherlands)

    Liu, Xubing; Liang, Minxia; Etienne, Rampal S.; Wang, Yongfan; Staehelin, Christian; Yu, Shixiao

    Observational evidence increasingly suggests that the JanzenConnell effect extends beyond the species boundary. However, this has not been confirmed experimentally. Herein, we present both observational and experimental evidence for a phylogenetic JanzenConnell effect. In a subtropical forest in


    The low subtropical zone is the most populated and seriously degraded area in China; therefore, highly efficient restoration of degraded lands is the key to sustainable development of this region. An agro-forest restoration mode consisting of an Acacia mangium forest, a Citrus re...

  9. Subtropical Fruit Fly Invasions into Temperate Fruit Fly Territory in California's San Joaquin Valley (United States)

    Subtropical fruit fly species including peach fruit fly, Bactrocera zonata (Saunders); melon fly, B. cucurbitae (Coquillett); oriental fruit fly, B. dorsalis (Hendel); and Mediterranean fruit fly, Ceratitis capitata Weidemann, have been detected in the past decade in the San Joaquin Valley of Califo...

  10. Transformation and fate of microphytobenthos carbon in subtropical shallow subtidal sands: A

    NARCIS (Netherlands)

    Oakes, J.M.; Eyre, B.D.; Middelburg, J.J.


    Microphytobenthos (MPB) in photic sediments are highly productive but the fate of this production remains uncertain. Over 33 d, tracing of C-13 from added bicarbonate in subtropical shallow subtidal sand showed rapid transfer of MPB-derived carbon to deeper sediment; below 2 cm (31% within 60 h) and

  11. The western boundary current of the seasonal subtropical gyre in the Bay of Bengal

    Digital Repository Service at National Institute of Oceanography (India)

    Shetye, S.R.; Gouveia, A.D.; Shenoi, S.S.C.; Sundar, D.; Michael, G.S.; Nampoothiri, G.

    , and monthly mean wind stress, we propose that the poleward current is the western boundary current of a seasonal anticyclonic subtropical gyre which forms in the Bay during January, is best developed during March-April, and decays by June. The gyre...

  12. Influence of isentropic transport on seasonal ozone variations in the lower stratosphere and subtropical upper troposphere (United States)

    Jing, P.; Cunnold, D. M.; Yang, E.-S.; Wang, H.-J.


    The isentropic cross-tropopause ozone transport has been estimated in both hemispheres in 1999 based on the potential vorticity mapping of Stratospheric Aerosol and Gas Experiment 11 ozone measurements and contour advection calculations using the NASA Goddard Space Flight Center Global and Modeling Assimilation Office analysis. The estimated net isentropic stratosphere-to-troposphere ozone flux is approx.118 +/- 61 x 10(exp9)kg/yr globally within the layer between 330 and 370 K in 1999; 60% of it is found in the Northern Hemisphere, and 40% is found in the Southern Hemisphere. The monthly average ozone fluxes are strongest in summer and weakest in winter in both hemispheres. The seasonal variations of ozone in the lower stratosphere (LS) and upper troposphere (UT) have been analyzed using ozonesonde observations from ozonesonde stations in the extratropics and subtropics, respectively. It is shown that observed ozone levels increase in the UT over subtropical ozonesonde stations and decrease in the LS over extratropical stations in late spring/early summer and that the ozone increases in the summertime subtropical UT are unlikely to be explained by photochemical ozone production and diabatic transport alone. We conclude that isentropic transport is a significant contributor to ozone levels in the subtropical upper troposphere, especially in summer.

  13. Lysogenic infection in sub-tropical freshwater cyanobacteria cultures and natural blooms

    NARCIS (Netherlands)

    Steenhauer, L.M.; Pollard, P.C.; Brussaard, C.P.D.; Säwström, C.


    Lysogeny has been reported for a few freshwater cyanobacteria cultures, but it is unknown how prevalent it is in freshwater cyanobacteria in situ. Here we tested for lysogeny in (a) cultures of eight Australian species of subtropical freshwater cyanobacteria; (b) seven strains of one species:


    Murrell, Michael C. and Emile M. Lores. 2004. Phytoplankton and Zooplankton Seasonal Dynamics in a Subtropical Estuary: Importance of Cyanobacteria. J. Plankton Res. 26(3):371-382. (ERL,GB 1190). A seasonal study of phytoplankton and zooplankton was conducted from 1999-20...

  15. Evaluation of Colilert-18 for Detection of Coliforms and Eschericha coli in Subtropical Freshwater (United States)

    Chao, Kuo-Kuang; Chao, Chen-Ching; Chao, Wei-Liang


    The accuracy of Colilert-18 as a test for coliforms and Escherichia coli in subtropical freshwater was evaluated by using API 20E strips and fatty acid methyl ester analysis. The false-positive and -negative rates of detection were 7.4 and 3.5%, respectively, for E. coli and 9.6 and 6.3%, respectively, for coliforms. PMID:14766614

  16. Evaluation of Colilert-18 for Detection of Coliforms and Eschericha coli in Subtropical Freshwater


    Chao, Kuo-Kuang; Chao, Chen-Ching; Chao, Wei-Liang


    The accuracy of Colilert-18 as a test for coliforms and Escherichia coli in subtropical freshwater was evaluated by using API 20E strips and fatty acid methyl ester analysis. The false-positive and -negative rates of detection were 7.4 and 3.5%, respectively, for E. coli and 9.6 and 6.3%, respectively, for coliforms.

  17. Evaluation of Colilert-18 for detection of coliforms and Eschericha coli in subtropical freshwater. (United States)

    Chao, Kuo-Kuang; Chao, Chen-Ching; Chao, Wei-Liang


    The accuracy of Colilert-18 as a test for coliforms and Escherichia coli in subtropical freshwater was evaluated by using API 20E strips and fatty acid methyl ester analysis. The false-positive and -negative rates of detection were 7.4 and 3.5%, respectively, for E. coli and 9.6 and 6.3%, respectively, for coliforms.

  18. Sensitivity to low-temperature events: Implications for CO2 dynamics in subtropical coastal ecosystems (United States)

    Sparkle L. Malone; Jordan Barr; Jose D. Fuentes; Steven F. Oberbauer; Christina L. Staudhammer; Evelyn E. Gaiser; Gregory Starr


    We analyzed the ecosystem effects of low-temperature events (<5 °C) over 4 years (2009-2012) in subtropical short and long hydroperiod freshwater marsh and mangrove forests within Everglades National Park. To evaluate changes in ecosystem productivity, we measured temporal patterns of CO2 and the normalized difference vegetation index over the study period. Both...

  19. Ordinal abundance and richness of millipedes (Arthropoda: Diplopoda) in a subtropical wet forest in Puerto Rico (United States)

    Christina M. Murphy; Grizelle Gonzalez; Juliana. Belén


    Millipedes, among other soil fauna, are important components of ecosystems because of their role in nutrient cycling. In this study, we quantified the density, biomass, and richness (in terms of order) of millipedes along a toposequence (ridges, slopes, and valleys) and different ground layers (litter, humus, 0-5 cm soil depth, and 5-10 cm soil depth) in a subtropical...

  20. Seasonal influenza vaccine policy, use and effectiveness in the tropics and subtropics: a systematic literature review.

    NARCIS (Netherlands)

    Hirve, S.; Lambach, P.; Paget, J.; Vandemaele, K.; Fitzner, J.; Zhang, W.


    Aim: The evidence needed for tropical countries to take informed decisions on influenza vaccination is scarce. This paper reviews policy, availability, use and effectiveness of seasonal influenza vaccine in tropical and subtropical countries. Method: Global health databases were searched in three

  1. Diet preferences of goats in a subtropical dry forest and implications for habitat management (United States)

    Genie M. Fleming; Joseph Wunderle Jr.; David N. Ewert


    As part of an experimental study of using controlled goat grazing to manage winter habitat of the Kirtland’s warbler (Setophaga kirtlandii), an endangered Nearctic neotropical migratory bird, we evaluated diet preferences of domesticated goats within early successional subtropical dry forest in The Bahamas. We expected goats would show a low preference for two plants (...

  2. Comparison of stream nutrient conditions in a subtropical lowland watershed to EPA suggested criteria (United States)

    April Mason; Y. Jun Xu; Johnny M. Grace


    Nutrients such as nitrogen, phosphorus and organic carbon are essential to the health and diversity of stream ecosystems. However, excess nutrients can cause eutrophication, resulting in overgrowth of aquatic plants and decline of the ecosystem diversity. A paired-watershed study was initiated in a subtropical forested watershed within the Ouachita River Basin in...

  3. Understanding the life of a sandy beach polychaete of functional importance - Scolelepis squamata (Polychaeta: Spionidae) on Belgian sandy beaches (northeastern Atlantic, North Sea) (United States)

    Speybroeck, Jeroen; Alsteens, Lotte; Vincx, Magda; Degraer, Steven


    The cosmopolitan sandy beach polychaete Scolelepis squamata constitutes an important food resource for juvenile flatfish and wading birds in the northeastern Atlantic, thus playing an important role in sandy beach ecosystem functioning. However, its population dynamics and life history in this part of the world have gone widely uninvestigated. Eight beach transects on Belgian sandy beaches were sampled monthly from October 2003 until October 2004, in order to investigate seasonal trends in the species' abundance, biomass, secondary production, and patterns in reproduction and zonation. Average density, modal density and modal biomass (ash-free dry weight) (mean average density = 169 ± 9 SE ind/m 2; mean modal density = 505 ± 38 SE ind/m 2; mean modal biomass = 0.25 ± 0.02 SE g/m 2) did not exhibit major seasonal changes, whereas average biomass (0.081 ± 0.005 SE g/m 2) and individuals and biomass per strip transect (IST = 16286 ± 1330 SE ind/m; BMST = 7.8 + 0.7 SE g/m) did, peaking in May 2004. Production was calculated at 1.9 g/(m 2*year) (size-frequency method, SFM) and 0.88 g/(m 2*year) (mass specific growth rate method, MSGR) and mean annual biomass was 0.797 g/m 2; resulting in a P/B ratio of 2.40/year (SFM) and 1.11/year (MSGR), which is intermediate to moderately low compared to other polychaete species. Gravid individuals were found from February until August and a single recruitment period was observed from July until September. An average sex ratio of 1.41 ± 0.08 SE was calculated, with a female predominance. Highest densities (>200 ind/m 2) were mostly found above 3 m above MLLWS and at a median grain size from 190 to 320 μm. Average modal or peak density along each transect was situated from 3.95 m up to 4.40 m above MLLWS, in contrast to some other studies where the species was restricted to mid-tidal levels. Significant differences in elevation of peak density were found between non-gravid (411 ± 4 SE cm) and gravid (402 ± 5 SE cm) animals

  4. Topographic variation in aboveground biomass in a subtropical evergreen broad-leaved forest in China.

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    Dunmei Lin

    Full Text Available The subtropical forest biome occupies about 25% of China, with species diversity only next to tropical forests. Despite the recognized importance of subtropical forest in regional carbon storage and cycling, uncertainties remain regarding the carbon storage of subtropical forests, and few studies have quantified within-site variation of biomass, making it difficult to evaluate the role of these forests in the global and regional carbon cycles. Using data for a 24-ha census plot in east China, we quantify aboveground biomass, characterize its spatial variation among different habitats, and analyse species relative contribution to the total aboveground biomass of different habitats. The average aboveground biomass was 223.0 Mg ha(-1 (bootstrapped 95% confidence intervals [217.6, 228.5] and varied substantially among four topographically defined habitats, from 180.6 Mg ha(-1 (bootstrapped 95% CI [167.1, 195.0] in the upper ridge to 245.9 Mg ha(-1 (bootstrapped 95% CI [238.3, 253.8] in the lower ridge, with upper and lower valley intermediate. In consistent with our expectation, individual species contributed differently to the total aboveground biomass of different habitats, reflecting significant species habitat associations. Different species show differently in habitat preference in terms of biomass contribution. These patterns may be the consequences of ecological strategies difference among different species. Results from this study enhance our ability to evaluate the role of subtropical forests in the regional carbon cycle and provide valuable information to guide the protection and management of subtropical broad-leaved forest for carbon sequestration and carbon storage.

  5. Comparison of wastewater-associated contaminants in the bed sediment of Hempstead Bay, New York, before and after Hurricane Sandy (United States)

    Fisher, Shawn C.; Phillips, Patrick; Brownawell, Bruce J.; Browne, James


    Changes in bed sediment chemistry of Hempstead Bay (HB) have been evaluated in the wake of Hurricane Sandy, which resulted in the release of billions of liters of poorly-treated sewage into tributaries and channels throughout the bay. Surficial grab samples (top 5 cm) collected before and (or) after Hurricane Sandy from sixteen sites in HB were analyzed for 74 wastewater tracers and steroid hormones, and total organic carbon. Data from pre- and post-storm comparisons of the most frequently detected wastewater tracers and ratios of steroid hormone and of polycyclic aromatic hydrocarbon concentrations indicate an increased sewage signal near outfalls and downstream of where raw sewage was discharged. Median concentration of wastewater tracers decreased after the storm at sites further from outfalls. Overall, changes in sediment quality probably resulted from a combination of additional sewage inputs, sediment redistribution, and stormwater runoff in the days to weeks following Hurricane Sandy.

  6. Does human pressure affect the community structure of surf zone fish in sandy beaches? (United States)

    Costa, Leonardo Lopes; Landmann, Júlia G.; Gaelzer, Luiz R.; Zalmon, Ilana R.


    Intense tourism and human activities have resulted in habitat destruction in sandy beach ecosystems with negative impacts on the associated communities. To investigate whether urbanized beaches affect surf zone fish communities, fish and their benthic macrofaunal prey were collected during periods of low and high human pressure at two beaches on the Southeastern Brazilian coast. A BACI experimental design (Before-After-Control-Impact) was adapted for comparisons of tourism impact on fish community composition and structure in urbanized, intermediate and non-urbanized sectors of each beach. At the end of the summer season, we observed a significant reduction in fish richness, abundance, and diversity in the high tourist pressure areas. The negative association between visitors' abundance and the macrofaunal density suggests that urbanized beaches are avoided by surf zone fish due to higher human pressure and the reduction of food availability. Our results indicate that surf zone fish should be included in environmental impact studies in sandy beaches, including commercial species, e.g., the bluefish Pomatomus saltatrix. The comparative results from the less urbanized areas suggest that environmental zoning and visitation limits should be used as effective management and preservation strategies on beaches with high conservation potential.

  7. Influence of mycorrhizal fungi on the growth and development of sandy everlasting Helichrysum arenarium (L. Moench.

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    Anna K. Sawilska


    Full Text Available The significance of root colonization by mycorrhizal fungi for the growth and development of Helichrysum arenarium was investigated in two independent experiments. In the first experiment the association of root colonization level with the pluviothermal conditions within the growing season and the age of a natural plant population was analyzed. In the second one, under controlled conditions, the influence of artificial inoculation with the arbuscular fungus Glomus intraradices on the features of plants raised from achenes was studied. It was shown that hydrothermal conditions during blooming period had a greater influence on reproduction processes of sandy everlasting than both the population age (the secondary succession progress and the level of root colonization by mycorrhizal fungi. High amount of precipitation at plant generative development phase positively influences the potential and actual fertility of ramets. The presence of arbuscular fungus in the soil favors the growth and development of sandy everlasting specimens at their early growing stages: they have a better-developed root system and a greater photosynthetic area.

  8. Adsorption capacity of chosen sandy ground with respect to contaminants relocating with groundwater

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    Aniszewski Andrzej


    Full Text Available One of the most important problems concerning contaminant transport in the ground is the problem related to the definition of parameters characterizing the adsorption capacity of ground for the chosen contaminants relocating with groundwater. In this paper, for chloride and sulfate indicators relocating in sandy ground, the numerical values of retardation factors (Ra (treated as average values and pore groundwater velocities with adsorption (ux/Ra (in micro-pore ground spaces are taken into consideration. Based on 2D transport equation the maximal dimensionless concentration values (C*max c in the chosen ground cross-sections were calculated. All the presented numerical calculations are related to the unpublished measurement series which was marked in this paper as: October 1982. For this measurement series the calculated concentration values are compared to the measured concentration ones (C*max m given recently to the author of this paper. In final part of this paper the parameters characterizing adsorption capacity (Ra, ux/Ra are also compared to the same parameters calculated for the two earlier measurement series. Such comparison also allowed for the estimation of a gradual in time depletion of adsorption capacity for the chosen sandy ground.

  9. Gender differences in psychological reactions to Hurricane Sandy among New York Metropolitan Area residents. (United States)

    Hamama-Raz, Yaira; Palgi, Yuval; Shrira, Amit; Goodwin, Robin; Kaniasty, Krzysztof; Ben-Ezra, Menachem


    Hurricane Sandy was a natural disaster of large proportions--a category 3 storm at its peak intensity that struck New York Metropolitan Area on October, 2012. The death and destruction caused by a hurricane can rise numerous of mental health vulnerabilities such as, acute stress disorder, posttraumatic stress disorder, depression, and anxiety. Gender has been identified as one critical variable that can impact vulnerability to adverse effects of trauma, as well as how these reactions are managed. The present research provides an evaluation of gender differences regarding posttraumatic stress symptoms, recollections of national disasters and fears of future negative life events. It also aims to explore information seeking and sources of assistance that were utilized during Hurricane Sandy. An online survey sample of 1,000 people from New York Metropolitan Area completed a battery of self-report questionnaires four weeks after the storm. Results revealed that recollections of national disaster and fear of future events were found to be significantly different among women compared to men. Additionally, women were more inclined toward information seeking through Facebook than men, although no gender differences emerged when examining sources of support. The results indicate that disaster practitioners should tailor gender sensitive interventions.

  10. GPS detection of ultra-low-frequency crustal resonance caused by Hurricane Sandy (United States)

    Zhang, J.; Holt, W. E.; Blewitt, G.


    Using 5-minute solutions of vertical component GPS, processed from the CORS network, we observe spatially correlated displacements that appear to propagate for several hundreds of kilometers within the Northeastern U.S., just after the landfall of Hurricane Sandy. This displacement field lasts for about 4.5 hours and shows great attenuation when propagating from the coast into the mainland. Its amplitude is about 10 times bigger than that predicted by a static loading using traditional theory and models. We interpret the propagation of the time-dependent vertical displacement field as a Biot slow wave associated with a medium containing abundant water-filled fractures in the crust. This ultra-long period wave appears to have been excited by the large storm surge that impacted the coastal region during, and just prior to, the Sandy landfall. Our interpretation predicts three key features simultaneously: strong attenuation, low wave speed (no more than 100 m/s) and high displacement amplification (about 10 times). The observations may suggest that poroelastic behavior plays an important role in elastodynamics for the crust, especially for ultra low frequency loading.

  11. Light pollution reduces activity, food consumption and growth rates in a sandy beach invertebrate. (United States)

    Luarte, T; Bonta, C C; Silva-Rodriguez, E A; Quijón, P A; Miranda, C; Farias, A A; Duarte, C


    The continued growth of human activity and infrastructure has translated into a widespread increase in light pollution. Natural daylight and moonlight cycles play a fundamental role for many organisms and ecological processes, so an increase in light pollution may have profound effects on communities and ecosystem services. Studies assessing ecological light pollution (ELP) effects on sandy beach organisms have lagged behind the study of other sources of disturbance. Hence, we assessed the influence of this stressor on locomotor activity, foraging behavior, absorption efficiency and growth rate of adults of the talitrid amphipod Orchestoidea tuberculata. In the field, an artificial light system was assembled to assess the local influence of artificial light conditions on the amphipod's locomotor activity and use of food patches in comparison to natural (ambient) conditions. Meanwhile in the laboratory, two experimental chambers were set to assess amphipod locomotor activity, consumption rates, absorption efficiency and growth under artificial light in comparison to natural light-dark cycles. Our results indicate that artificial light have significantly adverse effects on the activity patterns and foraging behavior of the amphipods, resulting on reduced consumption and growth rates. Given the steady increase in artificial light pollution here and elsewhere, sandy beach communities could be negatively affected, with unexpected consequences for the whole ecosystem. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Utilization of Sandy Soil as the Primary Raw Material in Production of Unfired Bricks

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    Guilan Tao


    Full Text Available In this study, attempts were made to use sandy soil as the main raw material in making unfired bricks. The sprayed-cured brick specimens were tested for compressive and flexural strength, rate of water absorption, percentage of voids, bulk density, freezing/thawing, and water immersion resistance. In addition, the microstructures of the specimens were also studied using scanning electron microscope (SEM and X-ray diffraction (XRD technique. The test results show that unfired brick specimens with the addition of ground-granulated blast-furnace slag (GGBS tend to achieve better mechanical properties when compared with the specimens that added cement alone, with GGBS correcting particle size distribution and contributing to the pozzolanic reactions and the pore-filling effects. The test specimens with the appropriate addition of cement, GGBS, quicklime, and gypsum are dense and show a low water absorption rate, a low percentage of voids, and an excellent freezing/thawing and water immersion resistance. The SEM observation and XRD analysis verify the formation of hydrate products C–S–H and ettringite, providing a better explanation of the mechanical and physical behavior and durability of the derived unfired bricks. The results obtained suggest that there is a technical approach for the high-efficient comprehensive utilization of sandy soil and provide increased economic and environmental benefits.

  13. Microhabitat use by two rocky shore gastropods in an intertidal sandy substrate with rocky fragments

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    A. Turra

    Full Text Available Sandy beaches in some areas of the São Sebastião Channel in southeastern Brazil have unremittingly undergone a variety of impacts, including the deposition of rock fragments in the intertidal region. Consequently, these environments support a rich fauna comprising both sandy beach and rocky shore organisms. Two rocky shore gastropods, Tegula viridula and Morula nodulosa, are particularly abundant in such environments. An evaluation of the use of microhabitats by these two species revealed that they occupy the available microhabitats in different proportions and the presence of one species is associated with the absence of the other. Morula nodulosa is randomly dispersed, occupying mostly areas with rock fragments covered with sediment and branching brown algae. Tegula viridula shows a clumped dispersion associated with the patchiness of the microhabitats used: the presence of encrusting green algae and absence of sediment and branching brown algae covering the rocks. These findings suggest T. viridula has a lower tolerance than M. nodulosa to sand inundation of the rocky fragments, a stochastic event common to the environment in question.

  14. Effect of coastal urbanization on sandy beach coleoptera Phaleria maculata (Kulzer, 1959) in northern Chile. (United States)

    González, Sergio A; Yáñez-Navea, Katherine; Muñoz, Mauricio


    The beetle Phaleria maculata is a common inhabitant of the upper intertidal fringe of Chilean beaches. Anthropogenic intervention in coastal areas has increased intensely, leading to changes in the flora and fauna of sandy beaches. To examine the impact of human activities on P. maculata, we studied several beaches along the northern Chilean coast. Beaches were characterized based on morphodynamics and the level of intervention, leading to the estimation of an "Urbanization Index" based on various indicators. The analysis showed a significant inverse correlation between the rate of urbanization and night sky quality. Larval and adult beetles were almost absent on beaches with high levels of urbanization. The results of simple and multiple correlations based on nMDS ordination showed an inverse relationship between increases in urbanization and the abundance of beetles. Because darkling beetles are very sensitive to human interventions on sandy beaches, we suggest that they are ideal indicator organisms for the health of these environments. Copyright © 2014 Elsevier Ltd. All rights reserved.

  15. [Influencing mechanism of several shrubs and subshrubs on soil fertility in Keerqin sandy land]. (United States)

    Su, Yongzhong; Zhao, Halin; Zhang, Tonghui


    Keerqin sandy land is one of serious desertification areas in the semiarid zone of north China, and shrubs are the dominant plant life form and play an important role in the region. The effects of "fertile island" and rhizosphere of several shrubs and subshrubs were studied. The results showed that the concentrations of organic C, total N and total P, and values of electrical conductivity (EC) in the soils under the canopy of shrubs increased by 56%, 51%, 37%, and 51%, respectively, compared with those of the soils in open spaces, but there was no significant difference in pH value between the soils under shrub canopies and in open spaces. Shrub rhizosphere soils had significant higher contents of organic C, total N, and values of EC as well as lower pH value compared to the bulk soils, but there was no significant difference in total P between rhizosphere and bulk soils. There were close relationships between the properties in soils under shrub canopies and the rhizosphere soils, indicating that the development of "fertile island" were favorable to root growth and induced greater amount of rhizodeposition, and vice versa. Soils under Artemisia frigida and Caragada microphylla canopies and rhizospheres had significant higher organic C and total N contents than those of Artemisia halodendron and Salix gordejvii. This results suggested that shrubs were of vital importance for accumulation of nutrients and maintenance of soil fertility in Keerqin sandy land ecosystem.


    Directory of Open Access Journals (Sweden)

    Ahmad Hayam Brilian


    Full Text Available Komunikasi terjadi antara mahluk hidup yang satu dengan yang lain. Komunikasi yang sering digunakan oleh manusia adalah komunikasi verbal. Namun, beberapa orang yang menderita kecacatan parah tidak mampu berkomunikasi dengan baik. Penderita cacat parah tidak mampu menuliskan kata yang dikehendaki, apalagi untuk berkomunikasi secara lisan karena mengalami gangguan syaraf. Namun beberapa penderita cacat parah masih bisa mengedipkan matanya dengan normal. Sehingga perlu dibangun sebuah metode yang mampu menerjemahkan kedipan mata menjadi kata verbal. Salah satu bentuk pengkodean yang sering dipakai adalah sandi morse. Pemilihan ini disebabkan karena pola-pola yang terdapat pada sandi morse dapat ditirukan dengan menggunakan kedipan mata. Pada pengerjaan penelitian ini, sinyal electrooculogram (EOG diekstrak dari sinyal electroenchepalogram (EEG yang didapatkan dari perangkat Neurosky Mindwave. Tahap pertama dalam pengerjaan penelitian ini adalah desain sistem penerima data dari perangkat. Data yang diperoleh akan diekstraksi dengan menggunakan filter bandpass. Filter bandpass cenderung memberikan tren dari sinyal EEG karena cukup baik dalam membersihkan noise. Tren sinyal yang didapatkan diasumsikan sebagai sinyal EOG. Sinyal EOG hasil filterisasi akan diperkecil ukuran panjangnya untuk mempercepat proses klasifikasi dengan menggunakan k-nearest neighbor dan dynamic time warping. Dengan menggunakan data yang diambil dari 3 subjek uji, didapatkan nilai rata-rata akurasi sebesar 96,3%.

  17. Changes in physical properties of sandy soil after long-term compost treatment (United States)

    Aranyos, József Tibor; Tomócsik, Attila; Makádi, Marianna; Mészáros, József; Blaskó, Lajos


    Studying the long-term effect of composted sewage sludge application on chemical, physical and biological properties of soil, an experiment was established in 2003 at the Research Institute of Nyíregyháza in Hungary. The applied compost was prepared from sewage sludge (40%), straw (25%), bentonite (5%) and rhyolite (30%). The compost was ploughed into the 0-25 cm soil layer every 3rd year in the following amounts: 0, 9, 18 and 27 Mg ha-1 of dry matter. As expected, the compost application improved the structure of sandy soil, which is related with an increase in the organic matter content of soil. The infiltration into soil was improved significantly, reducing the water erosion under simulated high intensity rainfall. The soil compaction level was reduced in the first year after compost re-treatment. In accordance with the decrease in bulk density, the air permeability of soil increased tendentially. However, in the second year the positive effects of compost application were observed only in the plots treated with the highest compost dose because of quick degradation of the organic matter. According to the results, the sewage sludge compost seems to be an effective soil improving material for acidic sandy soils, but the beneficial effect of application lasts only for two years.

  18. Electrical Resistivity Based Empirical Model For Delineating Some Selected Soil Properties On Sandy-Loam Soil

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    Full Text Available Electrical Resistivity ER survey was conducted on a Sandy-loam soil with a view to evaluate some selected soil properties. Electrical Resistivity was measured from the soil surface at 0 0.3 m ER30 and 0 0.9 m ER90 soil depths using multi-electrode Wenner array and Miller 400D resistance meter. Soil samples were collected to a depth 0.3 m at points where ER was measured and analyzed for properties such as Organic Matter OM Cation Exchange Capacity CEC Soil Water Content SWC Sand Silt and Clay contents using standard methods. The results indicated that lower ER areas exhibit higher content of soil properties than higher ER areas. The ER90 correlates insignificantly to the soil properties while ER30 correlates significantly to the soil properties except clay r 0.63 - 0.75. The relationship between ER30 and soil properties were best fitted to multiple linear regression R2 0.90 and Boltzmann distribution R2 0.80 - 0.84. The study indicates the ability of ER to delineate some soil properties influencing yield on sandy-loam soil. This will help farmers take decisions that can improve yields.

  19. Hurricane Sandy and Adaptation Pathways in New York: Lessons from a First-Responder City (United States)

    Rosenzweig, Cynthia; Solecki, William


    Two central issues of climate change have become increasingly evident: Climate change will significantly affect cities; and rapid global urbanization will increase dramatically the number of individuals, amount of critical infrastructure, and means of economic production that are exposed and vulnerable to dynamic climate risks. Simultaneously, cities in many settings have begun to emerge as early adopters of climate change action strategies including greenhouse gas mitigation and adaptation. The objective of this paper is to examine and analyze how officials of one city - the City of New York - have integrated a flexible adaptation pathways approach into the municipality's climate action strategy. This approach has been connected with the City's ongoing response to Hurricane Sandy, which struck in the October 2012 and resulted in damages worth more than US$19 billion. A case study narrative methodology utilizing the Wise et al. conceptual framework (see this volume) is used to evaluate the effectiveness of the flexible adaptation pathways approach in New York City. The paper finds that Hurricane Sandy serves as a ''tipping point'' leading to transformative adaptation due to the explicit inclusion of increasing climate change risks in the rebuilding effort. The potential for transferability of the approach to cities varying in size and development stage is discussed, with elements useful across cities including the overall concept of flexible adaptation pathways, the inclusion of the full metropolitan region in the planning process, and the co-generation of climate-risk information by stakeholders and scientists.

  20. Assessment of Fate of Thiodicarb Pesticide in Sandy Clay Loam Soil

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    M. A. Bajeer


    Full Text Available In present study the fate of thiodicarb pesticide in sandy clay loam soil was investigated through its adsorption and leaching using HPLC. Experimental results revealed that thiodicarb follows first order kinetic with rate constant value of 0.711 h-1 and equilibrium study showed that Freundlich model was best fitted with multilayer adsorption capacity 3.749 mol/g and adsorption intensity 1.009. Therefore, adsorption of thiodicarb was multilayer, reversible and non-ideal. Leaching study has indicated intermediate mobility of thiodicarb with water due to its solubility, while field study showed the non-leacher nature. However both adsorption and leaching were heavily affected by soil characteristics. As the soil taken was sandy clay loam hence due to clay texture adsorption was higher because of vacant sites existing and greater surface area. For this the pesticide has remained adsorbed in above 20 cm soil layer as clearly seen from field study, minor amount was recorded in third layer of soil having 21-30 cm depth. The leached amount of thiodicarb in first and last part of water was 1.075 and 0.003 ng/µl. The general trend observed for adsorption in column and field soil was decreased downwards from 2.027 to 0.618 and 5.079 to 0.009 ng/µl.

  1. Projectile Penetration into Sandy Soil Confined by a Honeycomb-Like Structure

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    Weiming Luo


    Full Text Available HPS (Honeycomb-like Protective Structure is a newly proposed protective structure filled with sandy soil. In order to investigate the penetration resistance of the structure, numerical simulations based on SPH method had been carried out by using LS-DYNA, which are corresponding to the experiments. The calibrated model leads to reasonable predictions of the dynamic responses and damage modes of the HPS. More situations were carried out taking factors influencing the penetration into consideration, including point of impact, angle of impact, and projectile caliber. Penetration mode was established by analyzing the energy dissipation and investigating the mechanism from the phenomenological viewpoint. Simulation results show that the resisting forces and the torque that act on the long rod projectile would be greater than those acting on the short one when instability occurred. Besides, approximate 45° angle of impact was formed in the case of off-axis, which has a certain influence on the ballistic stability, resulting in more kinetic energy of projectile dissipating in HPS and less depth of penetration. The kinetic energy of projectile dissipated in sandy soil largely and the strip slightly, and the former was greater than the sum of the latter.

  2. Human activity accelerating the rapid desertification of the Mu Us Sandy Lands, North China (United States)

    Miao, Yunfa; Jin, Heling; Cui, Jianxin


    Over the past several thousand years, arid and semiarid China has experienced a series of asynchronous desertification events in its semiarid sandy and desert regions, but the precise identification of the driving forces of such events has remained elusive. In this paper we identify two rapid desertification events (RDEs) at ~4.6 ± 0.2 ka BP and ~3.3 ± 0.2 ka BP from the JJ Profile, located in the eastern Mu Us Sandy Lands. These RDEs appear to have occurred immediately following periods marked by persistently frequent and intense fires. We argue that such fire patterns, directly linked to an uncontrolled human use of vegetation as fuel, played a key role in accelerating RDEs by ensuring that the land surface was degraded beyond the threshold required for rapid desertification. This would suggest that the future use of a massive and sustained ecological program of vegetation rehabilitation should reduce the risk of destructive fire. PMID:26961705

  3. Decomposition of the organic matter of natural and concentrated vinasse in sandy and clayey soils. (United States)

    Possignolo-Vitti, Nadia Valério; Bertoncini, Edna Ivani; Vitti, André Cesar


    Vinasse has been used as fertilizer by sugarcane growers, due to its potential to completely replace mineral fertilizers. However, if the application is not adequate, this practice may cause environmental contamination. This study used a respirometry test to evaluate the organic matter (OM) decomposition present in natural vinasse and concentrated vinasse (CV), with or without urea addition. The experiment involved two soil types and two types of vinasse at different application rates. The vinasse chemical characterization showed high levels of pseudo-total potassium (K) in both vinasses, which are not considered in the application rates. Decomposition rates above 90% and between 70 and 80% were obtained for sandy and clayey soils, respectively, over a brief 41-day period, indicating rapid OM decomposition. Positive priming effect was observed for CV and CV + urea treatments in sandy soil. An important implication of these findings revealed that K not available in vinasse was released in the soil solution by the OM mineralization, indicating the possibility of overestimation in the vinasse application rates. Therefore, K pseudo-total values should be considered in the calculation of the vinasse application rates. However, studies involving K mobility into soil are needed to validate this hypothesis.

  4. Zeolite and Hucalcia as Coating Material for Improving Quality of NPK Fertilizer in Costal Sandy Soil

    Directory of Open Access Journals (Sweden)



    Full Text Available he growth and yield of plants are mainly a function of the quantity of fertilizer and water. In coastal sandy soil, nutrient losses and dry soils are seriously problems. The objective of the research was to study effect of zeolite and hucalci concentrations as NPK coating materials on NPK qualities i.e. water adsorption and release of N, P and K. The research used a coastal sandy soil as media. It was conducted in a laboratory of Soil Science Department, Gadjah Mada University from July to August 2009. Experimental design used was a factorial in a completely randomized design. The first factor was hucalci concentration, consisted of 10% (H1, 20% (H2, and 30% (H3. The second factor was zeolite concentration, consisted of 25% (Z1, 50% (Z2, 75% (Z3, and 100% (Z4. NPK fertilizer (without coating used as a control. The results showed that hucalci and zeolite had a capability to increase water adsorption and to retard the release of N, P, K. The coated NPK with hucalci 30% and zeolite 100% had the highest quality in water absorption, water retention and release of nutrients.

  5. Hurricane Sandy science plan: impacts of storm surge, including disturbed estuarine and bay hydrology (United States)

    Caskie, Sarah A.


    Hurricane Sandy devastated some of the most heavily populated eastern coastal areas of the Nation. With a storm surge peaking at more than 19 feet, the powerful landscape-altering destruction of Hurricane Sandy is a stark reminder of why the Nation must become more resilient to coastal hazards. In response to this natural disaster, the U.S. Geological Survey (USGS) received a total of $41.2 million in supplemental appropriations from the Department of the Interior (DOI) to support response, recovery, and rebuilding efforts. These funds support a science plan that will provide critical scientific information necessary to inform management decisions for recovery of coastal communities, and aid in preparation for future natural hazards. This science plan is designed to coordinate continuing USGS activities with stakeholders and other agencies to improve data collection and analysis that will guide recovery and restoration efforts. The science plan is split into five distinct themes: • Coastal topography and bathymetry • Impacts to coastal beaches and barriers

  6. Deposition of large organic particles (macrodetritus in a sandy beach system (Puck Bay, Baltic Sea

    Directory of Open Access Journals (Sweden)

    Lech Kotwicki


    Full Text Available The aim of this study was to evaluate the amount of organic macrodetritus deposited on the sandy shores of the southern Baltic, and to determine the type of washout material and their chemical composition (carbon and nitrogen.     Over 900 samples of macrodetritus (particles retained on a 0.5 mm sieve were collected from seven sampling locations along a 120 km stretch of coastline in Poland at monthly intervals in 2002. Analysis of the C and N content of several categories of detritus supplied information about seasonal changes in and the ageing of algal debris, and indicated that the amount of carrion is constant; the latter is apparently always metabolised very rapidly. The annual deposition of macroalgal detritus on this coast was estimated at 15 000 tonnes fresh weight, that is around 75% of the primary production of filamentous macroalgae in Puck Bay.     In comparison with the amounts of kelp deposited on sandy beaches in South Africa (Griffiths & Stenton-Dozey 1981, the massive seaweed washouts on Mediterranean beaches (Morand & Briand 1996, or the deposition of algal mats in the northern Baltic (Norkko & Bonsdorff 1996a, the quantities of macrodetritus on the shore in the study area are average, even allowing for the fact that the Baltic Sea is highly eutrophic (HELCOM 2005.

  7. Effect of Coated Urea with Humic-Calcium on Transformation of Nitrogen in Coastal Sandy Soil: A Soil Column Method

    Directory of Open Access Journals (Sweden)



    Full Text Available Effect of Coated Urea with Humic-Calcium on Transformation of Nitrogen in Coastal Sandy Soil: A Soil ColumnMethod (Sulakhudin, A Syukur, D Shiddieq and T Yuwono: In coastal sandy soil, mainly nitrogen losses due toleaching resulted to low fertilizer efficiency. Slow-release N fertilizers are proposed to minimize these losses, andhumic-calcium coated urea has been examined. A soil column method was used to compare the effects of coated ureawith humic-calcium on transformation and leaching loss of N in coastal sandy soil. The experiment aid to compare twokinds sources of humic substances (cow manure and peat which mixed with calcium as coated urea on transformation,vertical distribution and leaching N in coastal sandy soil. The concentration of humic-calcium coated urea i.e.1%, 5%and 10% based on their weight. The results showed that urea coated with humic-calcium from cow manure (UCHMand humic-calcium from peat (UCHP increased the N total and available N in the soil and decreased leaching loss ofN from the soil column. Compared to UCHP, UCHM in all concentration showed N-nitrate higher than N-ammonium onincubation length 2, 4 and 6 weeks. The N leached from a costal sandy soil with application coated urea with UCHMranged from 21.18% to 23.72% of the total N added as fertilizer, for coated urea with UCHP they ranged between21.44% and 23.25%, whereas for urea (control reached 29.48%. Leaching losses of mineral N were lower when ureacoated with UCHM compared to urea coated with UCHP or urea fertilizer. The study concluded that the UCHM isbetter than UCHP in decreasing N leached from coastal sandy soil

  8. Hurricane Sandy 2013 National Wetlands Inventory Habitat Classification (habitat analysis of coastal federal lands located within high impact zones of Hurricane Sandy, October 2012) (United States)

    Jones, William R.


    Hurricane Sandy directly hit the Atlantic shoreline of New Jersey during several astronomical high tide cycles in late October, 2012. The eastern seaboard areas are subject to sea level rise and increased severity and frequency of storm events, prompting habitat and land use planning changes. Wetland Aquatic Research Center (WARC) has conducted detailed mapping of marine and estuarine wetlands and deepwater habitats, including beaches and tide flats, and upland land use/land cover, using specially-acquired aerial imagery flown at 1-meter resolution.These efforts will assist the U.S. Fish and Wildlife Service (USFWS) continuing endeavors to map the barrier islands adhering to Coastal Barrier Resources Act (CBRA) guidelines. Mapped areas consist of selected federal lands including, National Park Service areas, USFWS National Wildlife Refuges, and selected CBRA Units, including barrier islands and marshes in New York and New Jersey. These vital wetland areas are important for migratory waterfowl and neotropical bird habitats, wildlife food chain support and nurseries for shellfish and finfish populations. Coastal wetlands also play an important function as storm surge buffers. This project includes mapping of dominant estuarine wetland plant species useful for wetland functional analysis and wildlife evaluation and management concerns. It also aims to integrate with and offer updated databases pertinent to: USFWS NWR and NWI programs, NOAA tide flats and beaches data, FEMA flood zone data, Natural Heritage Endangered and Threated Species, watershed management, and state and local land use planning.

  9. Quantifying the synergistic effect of the precipitation and land use on sandy desertification at county level: a case study in Naiman Banner, Northern China. (United States)

    Xiaodong, Ge; Jinren, Ni; Zhenshan, Li; Ronggui, Hu; Xin, Ming; Qing, Ye


    Assessing the driving forces of sandy desertification is fundamental and important for its control. It has been widely accepted that both climatic conditions and land use have great impact on sandy desertification in northern China. However, the relative role and synergistic effect of each driving force of sandy desertification are still not clear. In this paper, an indicator named as SI was defined to represent the integrated probability of sandy desertification caused by land use. A quantitative method was developed for characterizing the relative roles of annual precipitation and land use to sandy desertification in both spatial and temporal dimensions at county level. Results showed that, at county level, land use was the main cause of sandy desertification for Naiman Banner since 1987-2009. In the case of spatial dimension, the different combination of land use types decided the distribution of sandy desertification probability and finally decided the spatial pattern of bared sand land. In the case of temporal dimension, the synergistic effect of land use and precipitation highly influenced the spatial distribution of sandy desertification. Copyright © 2013 Elsevier Ltd. All rights reserved.

  10. Hurricane Sandy's Fingerprint: Ripple Bedforms at an Inner Continental Shelf Sorted Bedform Field Site (United States)

    DuVal, C.; Trembanis, A. C.; Beaudoin, J. D.; Schmidt, V. E.; Mayer, L. A.


    The hydrodynamics and seabed morphodynamics on the inner continental shelf and near shore environments have increasing relevance with continued development of near shore structures, offshore energy technologies and artificial reef construction. Characterizing the stresses on and response of the seabed near and around seabed objects will inform best practices for structural design, seabed mine and unexploded ordnance detection, and archaeological and benthic habitat studies. As part of an ONR funded project, Delaware's Redbird Reef is being studied for object scour and sorted bedform morphodynamics (Trembanis et al., in press). Central to this study are the effects of large storm events, such as Hurricane Sandy, which have had significant impact on the seafloor. Previous studies of inner shelf bedform dynamics have typically focused on near bed currents and bed stressors (e.g. Trembanis et al., 2004), sorted bedforms (e.g. Green et al., 2004) and object scour (e.g. Quinn, 2006; Trembanis et al., 2007; Mayer et al., 2007), but our understanding of the direct effects of objects and object scour on bedform morphodynamics is still incomplete. With prominent sorted bedform ripple fields, the Delaware Redbird artificial reef site, composed of 997 former New York City subway cars, as well as various military vehicles, tugboats, barges and ballasted tires, has made an ideal study location (Raineault et al., 2013 and 2011). Acoustic mapping of the Redbird reef three days prior to Sandy and two days after the following nor'easter, captured the extensive effects of the storms to the site, while acoustic Doppler current profilers characterized both the waves and bottom currents generated by the storm events. Results of the post-Sandy survey support the theory of sorted bedform evolution proposed by Murray and Thieler (2004). Acoustic imagery analysis indicates a highly energized and mobile bed during the storms, leading to self-organization of bedforms and creation of large

  11. Sandy River Delta Habitat Restoration : Annual Report, January 2008 - March 2009.

    Energy Technology Data Exchange (ETDEWEB)

    Dobson, Robin [USDA Forest Service, Columbia River Gorge National Scenic Area


    During the period 2008-2009, there were 2 contracts with BPA. One (38539) was dealing with the restoration work for 2007 and the other (26198) was an extension on the 2006 contract including the NEPA for Dam removal on the old channel of the Sandy River. For contract 38539, the Sandy River Delta Habitat Restoration project continued its focus on riparian hardwood reforestation with less emphasis on wetlands restoration. Emphasis was placed on Sundial Island again due to the potential removal of the dike and the loss of access in the near future. AshCreek Forest Management was able to leverage additional funding from grants to help finance the restoration effort; this required a mid year revision of work funded by BPA. The revised work not only continued the maintenance of restored hardwood forests, but was aimed to commence the restoration of the Columbia River Banks, an area all along the Columbia River. This would be the final restoration for Sundial Island. The grant funding would help achieve this. Thus by 2011, all major work will have been completed on Sundial Island and the need for access with vehicles would no longer be required. The restored forests continued to show excellent growth and development towards true riparian gallery forests. Final inter-planting was commenced, and will continue through 2010 before the area is considered fully restored. No new wetland work was completed. The wetlands were filled by pumping in early summer to augment the water levels but due to better rainfall, no new fuel was required to augment existing. Monitoring results continued to show very good growth of the trees and the restoration at large was performing beyond expectations. Weed problems continue to be the most difficult issue. The $100,000 from BPA planned for forest restoration in 2008, was augmented by $25,000 from USFS, $120,000 from OR150 grant, $18,000 from LCREP, and the COE continued to add $250,000 for their portion. Summary of the use of these funds are

  12. [Effects of desertification on C and N storages in grassland ecosystem on Horqin sandy land]. (United States)

    Zhao, Ha-lin; Li, Yu-qiang; Zhou, Rui-lian


    Sandy grassland is widespread in northern China, where desertification is very common because of overgrazing and estrepement. However, little is known about the effects of desertification on grassland C and N storages in this region. A field survey was conducted on Horqin sandy grassland, and desertification gradients were established to evaluate the effects of desertification on C and N storages in soil, plant, and litter. The results showed that desertification had deep effects on the contents and storages of grassland C and N. The C and N contents and storages in the grassland decreased significantly with increasing desertification degree. Comparing with those in un-desertified grassland, the C and N contents in lightly, moderately, heavily, and severely desertified grasslands decreased by 56.06% and 48.72%, 78.43% and 74.36%, 88.95% and 84.62%, and 91.64% and 84.62% in 0-100 cm soil layer, and by 8.61% and 6.43%, 0.05% and 25.71%, 2.58% and 27.14%, and 8. 61% and 27. 86% in plant components, respectively. Relevantly, the C and N storages decreased by 50.95% and 43.38%, 75.19% and 71.04%, 86.76% and 81.48%, and 91.17% and 83.17% in plant underground components in 0-100 cm soil layer, and by 25.08% and 27.62%, 30.90% and 46.55%, 73.84% and 80.62%, and 90.89% and 87.31% in plant aboveground components, respectively. In 2000, the total area of desertified grassland in Horqin sandy land was 30152. 7 km2, and the C and N loss via desertification reached up to 107.53 and 9.97 Mt, respectively. Correlation analysis indicated that the decrease of soil C and N contents was mainly come from the decreased soil fine particles caused by wind erosion in the process of desertification, and the degradation of soil texture- and nutrient status led finally to the rapid decrease of C and N storages in plant biomass and litter.

  13. Experimental evidences on the scaling behavior of a sandy porous media. (United States)

    Fallico, C.; Straface, S.; Chidichimo, F.; Ferrante, A. P.; De Bartolo, S.


    Various authors treated the scaling of the hydrodispersive parameters in porous media. Nevertheless several studies and reports finding in literature on this matter, specifically on the dispersivity increases with scale of measurement, are based on a statistical or experimental approach (Neuman, 1990; Wheatcraft & Tylor, 1988; Clauser, 1992; Schulze-Makuch, 2005). Following this last approach, we analysed the scale behaviour of a sandy porous media, the grain size of which was characterized carefully in laboratory. For this aim we carried out several tracer tests on three cylindrical samples of the considered sandy soil. The diameter of these samples was the same, equal to 0.0635 m, and the lengths respectively equal to 0.15 m, 0.30 m and 0.60 m. At the bottom and the top of the cylindrical sample two membrane were located to allow the water flow. The water arrived in the sample from the bottom by a plastic tube and came out from the top to exclude the presence of air in the soil sample. The flow was produced by a peristaltic pump, able to develop different rates and therefore different flow velocities. For all tests the utilized tracer was NaCl, that was melted in 50 ml of solution with concentration of 5 g/l. The letting in of the solution was performed immediately up pump, by a connection of plastic tubes and a tap. The tests was carried out at first letting in the tracer in short times and after repeating it with continuous letting in. In this way the tests was carried out, repeating them five times with different rates and, therefore, velocities. For each of test the breakthrough curves were obtained and successively the longitudinal dispersivity (αL) and the coefficient of longitudinal dispersion (DL) were calculated. These values, considering also the lengths of the samples, allowed to verify the scaling behaviour of the examined sandy porous media. In fact a specific law to describe the increase of αL with scale was determined. Analogously another law was

  14. Hurricane Sandy: Caught in the eye of the storm and a city's adaptation response (United States)

    Orton, P. M.; Horton, R. M.; Blumberg, A. F.; Rosenzweig, C.; Solecki, W.; Bader, D.


    The NOAA RISA program has funded the seven-institution Consortium for Climate Risk in the Urban Northeast (CCRUN) for the past five years to serve stakeholder needs in assessing and managing risks from climate variability and change. When Hurricane Sandy struck, we were in an ideal position, making flood forecasts and communicating NOAA forecasts to the public with dozens of media placements, translating the poorly understood flood forecasts into human dimensions. In 2013 and 2015, by request of New York City (NYC), we worked through the NYC Panel on Climate Change to deliver updated climate risk assessment reports, to be used in the post-Sandy rebuilding and resiliency efforts. These utilized innovative methodologies for probabilistic local and regional sea level change projections, and contrasted methods of dynamic versus (the more common) static flood mapping. We participated in a federal-academic partnership that developed a Sea Level Tool for Sandy Recovery that integrates CCRUN sea level rise projections with policy-relevant FEMA flood maps, and now several updated flood maps and coastal flood mapping tools (NOAA, FEMA, and USACE) incorporate our projections. For the adaptation response, we helped develop NYC's $20 billion flood adaptation plan, and we were on a winning team under the Housing and Urban Development Rebuild By Design (RBD) competition, a few of the many opportunities that arose with negligible additional funding and which CCRUN funds supported. Our work at times disrupted standard lines of thinking, but NYC showed an openness to altering course. In one case we showed that an NYC plan of wetland restoration in Jamaica Bay would provide no reduction in flooding unless deep-dredged channels circumventing them were shallowed or narrowed. In another, the lead author's RBD team challenged the notion at one location that levees were the solution to accelerating sea level rise, developing a plan to use ecological breakwaters and layered components of

  15. Mapping canopy gaps in an indigenous subtropical coastal forest using high resolution WorldView-2 data

    CSIR Research Space (South Africa)

    Malahlela, O


    Full Text Available Invasive species usually colonize canopy gaps in tropical and sub-tropical forests, which results in loss of native species. Therefore, an understanding of the location and distribution of canopy gaps will assist in predicting the occurrence...

  16. Artificial long-day photoperiod in the subtropics increases milk production in goats giving birth in late autumn

    National Research Council Canada - National Science Library

    Flores, M J; Flores, J A; Elizundia, J M; Mejía, A; Delgadillo, J A; Hernández, H


    Two experiments were conducted to determine whether exposure to a photoperiod of artificial long days in autumn increased milk yield in subtropical goats milked once (Exp. I) or twice daily (Exp. II). In Exp...

  17. Satellite detection of orographic gravity‐wave activity in the winter subtropical stratosphere over Australia and Africa

    National Research Council Canada - National Science Library

    Eckermann, S. D; Wu, D. L


    Orographic gravity‐wave (OGW) parameterizations in models produce waves over subtropical mountain ranges in Australia and Africa that propagate into the stratosphere during austral winter and deposit momentum, affecting weather and climate...

  18. Investigation on the components removed in loss on ignition test of sandy crushed construction and demolition waste. (United States)

    Asakura, Hiroshi; Yamada, Masato; Inoue, Yuzo; Watanabe, Yoichi; Ono, Yusaku


    Processed sandy residue generated from mixed construction and demolition waste (mixed C&D-W) was investigated for possible deposition in landfill. The basic properties and the components removed in the loss on ignition (LOI) test were examined. The target material for decreasing LOI was elucidated and the validity of LOI used as landfill standard for inert industrial solid waste was discussed. LOI of most of the samples was above 5% and therefore, in principle, processed sandy residue should not be deposited in inert-type landfill. As LOI of sandy residue was mainly due to bound water, the LOI could not be decreased to below 5% even if wood, which is the major organic matter in the sandy residue, was removed. However, decreasing the amount of wood could lead to a subsequent decrease in the amount of dissolved organic matter. Therefore, the LOI of processed mixed C&D-W used as landfill standard for inert industrial solid waste should be re-evaluated.

  19. Volatilization of tri-allate, ethoprophos and parathion measured with four methods after spraying on a sandy soil

    NARCIS (Netherlands)

    Bor, G.; Berg, van den F.; Smelt, J.H.; Smidt, R.A.; Peppel-Groen, van de A.E.; Leistra, M.


    At about eleven times after application of tri-allate, ethoprophos and parathion to a sandy soil, their rates of volatilization were determined by the aerodynamic method (AD), the Bowen-ratio method (BR), the theoretical-profile method (TP) and the Box method. The volatilization was highest for

  20. Movement of water, bromide ion and the pesticides ethoprophos and bentazone measured in a sandy soil in Vredepeel (The Netherlands)

    NARCIS (Netherlands)

    Boesten, J.J.T.I.; Pas, van der L.J.T.


    The aim of this study was to collect a data set suitable for testing pesticide leaching models in the case of a Dutch sandy soil with a shallow groundwater table. The movement of water, bromide ion and the behaviour of the pesticides ethoprophos and bentazone was studied. The substances were applied

  1. Movement of water, bromide and the pesticides ethoprophos and bentazone in a sandy soil: the Vredepeel data set

    NARCIS (Netherlands)

    Boesten, J.J.T.I.; Pas, van der L.J.T.


    The aim of this study was to collect a data set suitable for testing pesticide leaching models in the case of a Dutch sandy soil with a shallow groundwater table. The movement of water, bromide ion and the behaviour of the pesticides ethoprophos and bentazone was studied. The substances were applied

  2. Effects of deposition of heavy-metal-polluted harbor mud on microbial diversity and metal resistance in sandy marine sediments

    DEFF Research Database (Denmark)

    Toes, Ann-Charlotte M; Finke, Niko; Kuenen, J Gijs


    Deposition of dredged harbor sediments in relatively undisturbed ecosystems is often considered a viable option for confinement of pollutants and possible natural attenuation. This study investigated the effects of deposition of heavy-metal-polluted sludge on the microbial diversity of sandy...

  3. Transport of humic and fulvic acids in relation to metal mobility in a copper-contaminated acid sandy soil

    NARCIS (Netherlands)

    Weng, L.; Fest, E.P.M.J.; Filius, J.; Temminghoff, E.J.M.; Riemsdijk, van W.H.


    The transport of inorganic and organic pollutants in water and soil can be strongly influenced by the mobility of natural dissolved organic matter (DOM). In this paper, the transport of a humic acid (HA) and a fulvic acid (FA) in a copper-contaminated acid sandy soil was studied. The data showed

  4. Ni adsorption and Ni-Al LDH precipitation in a sandy aquifer: An experimental and mechanistic modeling study

    NARCIS (Netherlands)

    Regelink, I.C.; Temminghoff, E.J.M.


    Mining activities and industries have created nickel (Ni) contaminations in many parts of the world. The objective of this study is to increase our understanding of Ni adsorption and Nickel-Aluminium Layered Double Hydroxide (Ni-Al LDH) precipitation to reduce Ni mobility in a sandy soil aquifer. At

  5. Hydrological Components of a Young Loblolly Pine Plantation on a Sandy Soil with Estimates of Water Use and Loss (United States)

    Deborah A. Abrahamson; Phillip M. Dougherty; Stanley J. Zarnoch


    Fertilizer and irrigation treatments were applied in a 7- to l0-year-old loblolly pine (Pinus taeda L.) plantation on a sandy soil near Laurinburg, North Carolina. Rainfall, throughfall, stemflow, and soil water content were measured throughout the study period. Monthly interception losses ranged from 4 to 15% of rainfall. Stemflow ranged from 0.2...

  6. Impacts of long-term waste-water irrigation on the development of sandy Luvisols: consequences for metal pollutant distributions

    NARCIS (Netherlands)

    Oort, van F.; Jongmans, A.G.; Lamy, I.; Baize, D.; Chevallier, P.


    Studies relating macro- and microscopic aspects of impacts of long-term contaminative practices on soils are scarce. We performed such an approach by assessing the fate of metal pollutants in an area close to Paris, where sandy Luvisols were irrigated for 100 years with urban waste water. As a

  7. Woodland dynamics as a result of settlement relocation on Pleistocene sandy soils in The Netherlands (200 BC – 1400 AD).

    NARCIS (Netherlands)

    Groenewoudt, B.; Spek, Mattheus


    In this paper we investigate the potential of charcoal kilns as indicators (proxy data) of the interaction between settlement dynamics and the history of woodland presence, composition and structure. The results demonstrate that in our research area (Pleistocene sandy soils of the Netherlands)

  8. Biochar increases plant-available water in a sandy loam soil under an aerobic rice crop system

    NARCIS (Netherlands)

    Melo Carvalho, de M.T.; Holanda Nunes Maia, de A.; Madari, B.E.; Bastiaans, L.; Oort, van P.A.J.; Heinemann, A.B.; Soler da Silva, M.A.; Petter, F.A.; Marimon-Junior, B.H.; Meinke, H.B.


    The main objective of this study was to assess the impact of biochar rate (0, 8, 16 and 32 Mg ha-1) on the water retention capacity (WRC) of a sandy loam Dystric Plinthosol. The applied biochar was a by-product of slow pyrolysis (~450 °C) of eucalyptus wood, milled to pass through a 2000 µm sieve

  9. Subsidence estimation of breakwater built on loosely deposited sandy seabed foundation: Elastic model or elasto-plastic model

    Directory of Open Access Journals (Sweden)

    Jianhua Shen


    Full Text Available In offshore area, newly deposited Quaternary loose seabed soils are widely distributed. There are a great number of offshore structures has been built on them in the past, or will be built on them in the future due to the fact that there would be no very dense seabed soil foundation could be chosen at planed sites sometimes. However, loosely deposited seabed foundation would bring great risk to the service ability of offshore structures after construction. Currently, the understanding on wave-induced liquefaction mechanism in loose seabed foundation has been greatly improved; however, the recognition on the consolidation characteristics and settlement estimation of loose seabed foundation under offshore structures is still limited. In this study, taking a semi-coupled numerical model FSSI-CAS 2D as the tool, the consolidation and settlement of loosely deposited sandy seabed foundation under an offshore breakwater is investigated. The advanced soil constitutive model Pastor-Zienkiewics Mark III (PZIII is used to describe the quasi-static behavior of loose sandy seabed soil. The computational results show that PZIII model is capable of being used for settlement estimation problem of loosely deposited sandy seabed foundation. For loose sandy seabed foundation, elastic deformation is the dominant component in consolidation process. It is suggested that general elastic model is acceptable for subsidence estimation of offshore structures on loose seabed foundation; however, Young's modulus E must be dependent on the confining effective stress, rather than a constant in computation.

  10. 78 FR 7780 - Sunshine Act Meeting; FCC Announces Further Details for the First Post-Superstorm Sandy Field... (United States)


    ... networks during natural disasters and in other times of crisis. The first hearing will facilitate a wider... remind the public that presentations to decision-making personnel--including those that address network... Sandy, and help inform recommendations and actions to strengthen wired and wireless networks in the face...

  11. Performance on Addition and Subtraction Problems: Results from Achievement Monitoring Tests--Sandy Bay Study, Working Paper No. 325. (United States)

    Romberg, Thomas A.; And Others

    This paper reports the results from one of a series of related, collaborative studies carried out in Sandy Bay, Tasmania, Australia, in 1979 and 1980, examining how young children acquire the skills to represent and solve addition and subtraction problems. The purpose of this study was to relate children's cognitive processing capabilities and…

  12. EAARL Coastal Topography--Sandy Hook Unit, Gateway National Recreation Area, New Jersey, Post-Nor'Ida, 2009 (United States)

    U.S. Geological Survey, Department of the Interior — A digital elevation model (DEM) of a portion of the Sandy Hook Unit of the Gateway National Recreation Area in New Jersey, post-Nor'Ida (November 2009 nor'easter)...

  13. Impacts of acid deposition on concentrations and fluxes of solutes in acid sandy forest soils in the Netherlands.

    NARCIS (Netherlands)

    Vries, de W.; Grinsven, van J.J.M.; Breemen, van N.; Leeters, E.E.J.M.; Jansen, P.C.


    This article summarizes the most important impacts of acid atmospheric deposition on the soil solution chemistry of acid sandy forest soils in the Netherlands, by comparing and interpreting data from soil solution monitoring studies (18 stands) and a national soil solution survey (150 stands).

  14. Lasting effects of soil health improvements with management changes in cotton-based cropping systems in a sandy soil (United States)

    The soil microbial component is essential for sustainable agricultural systems and soil health. This study evaluated the lasting impacts of 5 years of soil health improvements from alternative cropping systems compared to intensively tilled continuous cotton (Cont. Ctn) in a low organic matter sandy...

  15. Garlic mustard and its effects on soil microbial communities in a sandy pine forest in central Illinois (United States)

    Alexander B. Faulkner; Brittany E. Pham; Truc-Quynh D. Nguyen; Kenneth E. Kitchell; Daniel S. O' Keefe; Kelly D. McConnaughay; Sherri J. Morris


    This study evaluated the impacts of garlic mustard (Alliaria petiolata), an invasive species, on soil microbial community dynamics in a pine plantation on sandy soils in central Illinois. In situ soil carbon dioxide efflux was significantly greater in invaded sites. Similarly, in vitro carbon mineralization was significantly greater for soils...

  16. 2013-2014 U.S. Geological Survey CMGP LiDAR: Post Sandy (MA, NH, RI) (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — TASK NAME: New England CMGP Sandy Lidar LiDAR Data Acquisition and Processing Production Task USGS Contract No. G10PC00057 Task Order No. G13PD00796 Woolpert Order...

  17. Target Diameter Models for Leuce Poplar Stands Growing on Sandy Soils

    Directory of Open Access Journals (Sweden)

    RÉDEI, Károly


    Full Text Available The fact that certain ecological factors fundamentally influencing tree growth have become unfavourable in Hungary in recent years, has led to the more extensive use of white poplar (and its hybrids in afforestation and forest regeneration. An intensive integrated research and development work has been carried out on the growth of Leuce poplars on sandy soils, including primarily the white poplar (Populus alba and its natural hybrid the grey poplar (Populus x canescens. The research revealed several factors influencing stand growth. The study presents a new, simplified tending operation model for Leuce poplar stands, as well as age, growing space and target diameter models suitable for qualitaty log production and for mass assortments. The simplicity of these practice-oriented models may foster the qualitative development of Leuce poplar management in Hungary.

  18. Effects of biochar and manure amendments on water vapor sorption in a sandy loam soil

    DEFF Research Database (Denmark)

    Arthur, Emmanuel; Tuller, Markus; Moldrup, Per


    properties of soils, especially on water retention at low matric potentials. To overcome this knowledge gap, the effects of combined BC (0 to 100 Mg ha-1) and manure (21 and 42 Mg ha-1) applications on water vapor sorption and specific surface area was investigated for a sandy loam soil. In addition......, potential impacts of BC aging were evaluated. All considered BC-amendment rates led to a distinct increase of water retention, especially for low matric potentials. The observed increases were attributed to a significant increase of soil organic matter contents and specific surface areas in BCamended soils....... Hysteresis of the water vapor sorption isotherms increased with increasing BC application rates. Biochar age did not significantly affect vapor sorption and SSA....

  19. Predictivity strength of the spatial variability of phenanthrene sorption across two sandy loam fields

    DEFF Research Database (Denmark)

    Soares, Antonio; Paradelo Pérez, Marcos; Møldrup, Per


    at the unsaturated zone, bulk topsoil samples were taken from the plough layer along two sandy loam fields with different texture and organic carbon (OC) content (140 samples in total). Batch experiments were performed by using the single-point adsorption method. Both related ranges for the contaminant partition...... coefficient, KD (L kg-1) and the organic carbon partition coefficient, KOC (L kg-1) agreed with the most frequently used models for PAH partitioning, as OC revealed a higher affinity towards sorption. More complex models, by applying different OC components, such as non-complexed organic carbon (NCOC......), and complexed organic carbon (COC) separately, were related with these findings, in particular if considering a sub-set of samples that included samples with Dexter n models proved...

  20. Simulation and control of morphological changes due to dam removal in the Sandy River, Oregon, USA

    Directory of Open Access Journals (Sweden)

    Y. Ding


    Full Text Available A one-dimensional channel evolution simulation model (CCHE1D is applied to assess morphological changes in a reach of the Sandy River, Oregon, USA, due to the Marmot Dam removal in 2007. Sediment transport model parameters (e.g. sediment transport capacity, bed roughness coefficient were calibrated using observed bed changes after the dam removal. The validated model is then applied to assess long-term morphological changes in response to a 10-year hydrograph selected from historical storm water records. The long-term assessment of sedimentation gives a reasonable prediction of morphological changes, expanding erosion in reservoir and growing deposition immediately downstream of the dam site. This prediction result can be used for managing and planning river sedimentation after dam removal. A simulation-based optimization model is also applied to determine the optimal sediment release rates during dam-removal that will minimize the morphological changes in the downstream reaches.

  1. Simulation and control of morphological changes due to dam removal in the Sandy River, Oregon, USA (United States)

    Ding, Y.; Altinakar, M. S.


    A one-dimensional channel evolution simulation model (CCHE1D) is applied to assess morphological changes in a reach of the Sandy River, Oregon, USA, due to the Marmot Dam removal in 2007. Sediment transport model parameters (e.g. sediment transport capacity, bed roughness coefficient) were calibrated using observed bed changes after the dam removal. The validated model is then applied to assess long-term morphological changes in response to a 10-year hydrograph selected from historical storm water records. The long-term assessment of sedimentation gives a reasonable prediction of morphological changes, expanding erosion in reservoir and growing deposition immediately downstream of the dam site. This prediction result can be used for managing and planning river sedimentation after dam removal. A simulation-based optimization model is also applied to determine the optimal sediment release rates during dam-removal that will minimize the morphological changes in the downstream reaches.

  2. Biochar amendment to coarse sandy subsoil improves root growth and increases water retention

    DEFF Research Database (Denmark)

    Bruun, Esben; Petersen, C. T.; Hansen, E.


    barley (Hordeum vulgare cv. Anakin) was grown in soil columns (diameter: 30 cm) prepared with 25 cm topsoil, 75 cm biochar-amended subsoil, and 30 cm un-amended subsoil lowermost placed on an impervious surface. Low-temperature gasification straw-biochar (at 0, 0.50, 1.0, 2.0, and 4.0 wt%) and slow......Crop yields and yield potentials on Danish coarse sandy soils are strongly limited due to restricted root growth and poor water and nutrient retention. We investigated if biochar amendment to subsoil can improve root development in barley and significantly increase soil water retention. Spring...... residues from bioenergy technologies such as straw-biochar is a promising option. © 2014 British Society of Soil Science....

  3. Analyzing Tropical Waves Using the Parallel Ensemble Empirical Model Decomposition Method: Preliminary Results from Hurricane Sandy (United States)

    Shen, Bo-Wen; Cheung, Samson; Li, Jui-Lin F.; Wu, Yu-ling


    In this study, we discuss the performance of the parallel ensemble empirical mode decomposition (EMD) in the analysis of tropical waves that are associated with tropical cyclone (TC) formation. To efficiently analyze high-resolution, global, multiple-dimensional data sets, we first implement multilevel parallelism into the ensemble EMD (EEMD) and obtain a parallel speedup of 720 using 200 eight-core processors. We then apply the parallel EEMD (PEEMD) to extract the intrinsic mode functions (IMFs) from preselected data sets that represent (1) idealized tropical waves and (2) large-scale environmental flows associated with Hurricane Sandy (2012). Results indicate that the PEEMD is efficient and effective in revealing the major wave characteristics of the data, such as wavelengths and periods, by sifting out the dominant (wave) components. This approach has a potential for hurricane climate study by examining the statistical relationship between tropical waves and TC formation.

  4. Pore-size distribution and compressibility of coarse sandy subsoil with added biochar

    DEFF Research Database (Denmark)

    Petersen, C. T.; Hansen, E.; Larsen, H. H.


    the effects of two fine-grained gasification biochars made of straw (LTST) and other materials (LTSN) and of one fast pyrolysis straw biochar (FPST) on pore-size distribution and soil compressibility when added to coarse sandy subsoil. Water retention and therefore pore-size distribution were affected...... systematically. All biochars converted drainable pore space with pore diameters in the range 60–300 µm into water-retaining pores of size 0.2–60 µm, which was taken as an estimate of available water capacity (AWC). Effects were linear over the whole range of biochar (0–4% by mass). The effect of LTST and LTSN...

  5. Eleven years' effect of conservation practices for temperate sandy loams: II. Soil pore characteristics

    DEFF Research Database (Denmark)

    Abdollahi, Lotfallah; Munkholm, Lars Juhl


    Conservation agriculture (CA) is regarded by many as a sustainable intensification strategy. Minimal soil disturbance in combination with residue retention are important CA components. This study examined the long-term effects of crop rotation, residue retention, and tillage on soil pore...... characteristics of two Danish sandy loams. Rotation R2 is a rotation of winter crops (mainly cereals) with residues retained, rotation R3 a mix of winter and spring crops (mainly cereals) with residues removed, and rotation R4 the same mix of winter and spring crops, but with residues retained. Each rotation...... included the tillage treatments: moldboard plowing to 20-cm depth (MP), harrowing to 8- to 10-cm depth (H) and direct drilling (D). Soil cores were taken from the topsoil (4–8, 12–16, 18–27 cm) in mid-autumn 2013 and early spring 2014. Water retention, air permeability, and gas diffusivity was determined...

  6. Field analysis: Physical and biological BTEX removal in a sandy aquifer

    Energy Technology Data Exchange (ETDEWEB)

    Sturman, P.J.; Cunningham, A.B. [Montana State Univ., Bozeman, MT (United States). Center for Biofilm Engineering; Wolfram, J.H. [Idaho National Engineering Lab., Idaho Falls, ID (United States); Niehaus, S. [Gosling-Czubak Associates, Traverse City, MI (United States)


    A sandy aquifer contaminated with dissolved phase BTEX compounds is currently being remediated through a combination of physical processes (pump and treat) and enhanced in-situ biodegradation. Extensive data collected from site monitoring and pump-back wells, along with knowledge of site sorptive and hydrodynamic properties, allowed the calculation of a contaminant mass balance, from which in-situ biotransformation was estimated. Data indicates that pump and treat removals of dissolved BTEX accounts for approximately half of the total reduction in BTEX mass on the site. Oxygen utilization data implicates biodegradation as responsible for the majority of remaining contaminant mass removal. Contaminant reductions in-situ appear to be associated with zones of increased contaminant-oxygen mixing located immediately downgradient from site injection wells.

  7. Documentation and hydrologic analysis of Hurricane Sandy in New Jersey, October 29–30, 2012 (United States)

    Suro, Thomas P.; Deetz, Anna; Hearn, Paul


    In 2012, a late season tropical depression developed into a tropical storm and later a hurricane. The hurricane, named “Hurricane Sandy,” gained strength to a Category 3 storm on October 25, 2012, and underwent several transitions on its approach to the mid-Atlantic region of the eastern coast of the United States. By October 28, 2012, Hurricane Sandy had strengthened into the largest hurricane ever recorded in the North Atlantic and was tracking parallel to the east coast of United States, heading toward New Jersey. On October 29, 2012, the storm turned west-northwest and made landfall near Atlantic City, N.J. The high winds and wind-driven storm surge caused massive damage along the entire coastline of New Jersey. Millions of people were left without power or communication networks. Many homes were completely destroyed. Sand dunes were eroded, and the barrier island at Mantoloking was breached, connecting the ocean with Barnegat Bay.Several days before the storm made landfall in New Jersey, the U.S. Geological Survey (USGS) made a decision to deploy a temporary network of storm-tide sensors and barometric pressure sensors from Virginia to Maine to supplement the existing USGS and National Oceanic and Atmospheric Administration (NOAA) networks of permanent tide monitoring stations. After the storm made landfall, the USGS conducted a sensor data recovery and high-water-mark collection campaign in cooperation with the Federal Emergency Management Agency (FEMA).Peak storm-tide elevations documented at USGS tide gages, tidal crest-stage gages, temporary storm sensor locations, and high-water-mark sites indicate the area from southern Monmouth County, N.J., north through Raritan Bay, N.J., had the highest peak storm-tide elevations during this storm. The USGS tide gages at Raritan River at South Amboy and Raritan Bay at Keansburg, part of the New Jersey Tide Telemetry System, each recorded peak storm-tide elevations of greater than 13 feet (ft)—more than 5 ft

  8. Marine meiofauna, carbon and nitrogen mineralization in sandy and soft sediments of Disko Bay, West Greenland

    DEFF Research Database (Denmark)

    Rysgaard, S.; Christensen, P.B.; Sørensen, Martin Vinther


    layers of the sediment. Algal photosynthetic activity and nitrogen uptake reduced nitrogen effluxes and denitrification rates. Sulfate reduction was the most important pathway for carbon mineralization in the sediments of the shallow-water station. In contrast, high bottom-water NO3- concentrations...... and was, together with organotrophic O-2 respiration, the most important pathway for carbon mineralization within these sediments. The obtained process rates were comparable to mineralization rates from much warmer localities, suggesting that benthic mineralization in arctic marine environments......Organic carbon mineralization was studied in a shallow-water (4 m), sandy sediment and 2 comparatively deep-water (150 and 300 m), soft sediments in Disko Bay, West Greenland. Benthic microalgae inhabiting the shallow-water locality significantly affected diurnal O-2 conditions within the surface...

  9. Developing a sustainable child and family service system after a community tragedy: Lessons from Sandy Hook. (United States)

    Hoagwood, Kimberly Eaton; Olin, Su-Chin Serene; Wang, Nicole M; Pollock, Michele; Acri, Mary; Glaeser, Elizabeth; Whitmyre, Emma D; Storfer-Isser, Amy; Horwitz, Sarah McCue


    This paper describes a systematic approach to assessing community services post-Sandy Hook shooting. An evaluation team was invited to develop a sustainability plan for community services in Newtown. Service organizations, providers and families were interviewed. Descriptive statistics were used to characterize the range of services; respondent perspectives were coded using content analysis. We found that Newtown has a broad array of community services, but respondent groups varied in their perceptions of service adequacy. Consensus existed about core components of an ideal service system, including centralizing access; coordinating care; personalizing and tailoring services for families; and providing evidence-based care. The strategic community assessment approach developed here may inform how communities examine their service capacity and develop sustainability plans post-disaster.

  10. Gas diffusion-derived tortuosity governs saturated hydraulic conductivity in sandy soils

    DEFF Research Database (Denmark)

    Masis Melendez, Federico; Deepagoda Thuduwe Kankanamge Kelum, Chamindu; de Jonge, Lis Wollesen


    Accurate prediction of saturated hydraulic conductivity (Ksat) is essential for the development of better distributed hydrological models and area-differentiated risk assessment of chemical leaching. The saturated hydraulic conductivity is often estimated from basic soil properties such as particle...... size distribution or, more recently, soil-air permeability. However, similar links to soil gas diffusivity (Dp/Do) have not been fully explored even though gas diffusivity is a direct measure of connectivity and tortuosity of the soil pore network. Based on measurements for a coarse sandy soil....../Do model to measured data, and subsequently linked to the cementation exponent of the wellestablished Revil and Cathles predictive model for saturated hydraulic conductivity. Furthermore, a two-parameter model, analogue to the Kozeny-Carman equation, was developed for the Ksat - Dp/Do relationships. All 44...

  11. Impact of Hurricane Sandy on the Shoreface and Inner Shelf, Offshore Long Island: Evidence for Ravinement? (United States)

    Goff, J. A.; Austin, J. A.; Flood, R. D.; Schwab, W. C.; Denny, J. F.; Christensen, B. A.; Browne, C. M.; Saustrup, S.


    In January 2013, approximately two months after Hurricane Sandy made landfall in the Mid-Atlantic Bight, a scientific team from the University of Texas Institute for Geophysics, partnering with colleagues at Adelphi and Stony Brook universities and the USGS, conducted marine geophysical and surficial sampling surveys both offshore and in the inshore bays of Long Island, NY. The primary scientific goal was to assess the impact of the storm on the shoreface and inner shelf. Sandy made landfall as a post-tropical cyclone near Brigantine, NJ, with 70-kt maximum sustained winds. However, its unusual trajectory and massive size created record storm surges along the heavily-populated NJ and NY coastlines. As a result, infrastructure in the NY metropolitan area was damaged, and the Long Island barrier island system was both breached in places and elsewhere seriously eroded. The surveys included ten days of operations aboard Stony Brook's R/V Seawolf, offshore of Long Beach and Fire Island, barrier islands south of Long Island, complementing ongoing land-based studies of Sandy's impact on the NY-NJ barrier island system. Data collection involved multibeam bathymetric swath mapping, CHIRP very high resolution acoustic subbottom profiling, and surface sediment (grab) sampling to provide ground truth for the geophysical data. We surveyed regions that had been previously surveyed, both by Stony Brook in 2001 and 2005 to support reef management, and by the USGS for coastal sedimentary research, most recently in 2011 offshore Fire Island. These areas include shoreface-attached sand ridges that may be exchanging sand with the barrier island shoreface. We focus on before-and-after data comparisons on the shoreface and inner shelf, searching in particular for evidence that the storm contributed significantly to ravinement, either by wave- or current-forced erosion along the shoreface or via migration of shoreface-attached or detached sand ridges on the inner shelf. The interpreted

  12. Physiological Responses of Jatropha to Drought Stress in Coastal Sandy Land Conditions

    Directory of Open Access Journals (Sweden)

    Bambang Djadmo Kertonegoro


    Full Text Available Jatropha curcas L., an important tropical biofuel crop, is reputed for its drought resistance, however, its ability to perform in dry conditions has still hardly been investigated. Changes in leaf water status, chlorophyll content, leaf surface temperature, stomatal conductance, proline and abcisic acid (ABA content, transpiration and photosynthetic rate were studied in four Jatropha genotypes (IP-1A, IP-2M, Local superior and Yellow leaf and subjected to drought stress in coastal sandy land conditions in Central Java, Indonesia. Drought stress significantly decreased the leaf water status, leaf chlorophyll content, stomatal conductance, transpiration and photosynthetic rate, and increased leaf temperature, proline and ABA content. Resistant genotypes (IP-1A and IP-2M had significantly higher leaf water status, chlorophyll content and photosynthetic rate than susceptible genotypes (Local superior and Yellow leaf. There were no differences between the Jatropha genotypes on leaf temperature, stomatal conductance and transpiration rate.

  13. Sidewinding with minimal slip: Snake and robot ascent of sandy slopes

    CERN Document Server

    Marvi, Hamidreza; Gravish, Nick; Astley, Henry; Travers, Matthew; Hatton, Ross L; Mendelson, Joseph R; Choset, Howie; Hu, David L; Goldman, Daniel I


    Limbless organisms such as snakes can navigate nearly all terrain. In particular, desert-dwelling sidewinder rattlesnakes (Crotalus cerastes) operate effectively on inclined granular media (such as sand dunes) that induce failure in field-tested limbless robots through slipping and pitching. Our laboratory experiments reveal that as granular incline angle increases, sidewinder rattlesnakes increase the length of their body in contact with the sand. Implementing this strategy in a physical robot model of the snake enables the device to ascend sandy slopes close to the angle of maximum slope stability. Plate drag experiments demonstrate that granular yield stresses decrease with increasing incline angle. Together, these three approaches demonstrate how sidewinding with contact-length control mitigates failure on granular media.

  14. Spatial variability of hydraulic conductivity of an unconfined sandy aquifer determined by a mini slug test

    DEFF Research Database (Denmark)

    Bjerg, Poul Løgstrup; Hinsby, Klaus; Christensen, Thomas Højlund


    The spatial variability of the hydraulic conductivity in a sandy aquifer has been determined by a mini slug test method. The hydraulic conductivity (K) of the aquifer has a geometric mean of 5.05 × 10−4 m s−1, and an overall variance of 1n K equal to 0.37 which corresponds quite well to the results...... obtained by two large scale tracer experiments performed in the aquifer. A geological model of the aquifer based on 31 sediment cores, proposed three hydrogeological layers in the aquifer concurrent with the vertical variations observed with respect to hydraulic conductivity. The horizontal correlation...... length of the hydraulic conductivity has been determined for each of the three hydrogeological layers and is found to be small (1–2.5 m). The asymptotic longitudinal dispersivity of the aquifer has been estimated from the variance in hydraulic conductivity and the horizontal correlation length...

  15. Effect of Particle Size and Soil Compaction on Gas Transport Parameters in Variably Saturated, Sandy Soils

    DEFF Research Database (Denmark)

    Hamamoto, Shoichiro; Møldrup, Per; Kawamoto, Ken


    the water retention curve), both exhibiting similar and exponential relationships with D50. Under variably saturated conditions, higher Dp and ka in coarser sand (larger D50) were observed due to rapid gas diffusion and advection through the less tortuous large-pore networks. In addition, soil compaction......The soil gas diffusion coefficient (Dp) and air permeability (ka) and their dependency on soil air content ( ) control gas diffusion and advection in soils. This study investigated the effects of average particle size (D50) and dry bulk density ( b) on Dp and ka for six sandy soils under variably...... saturated conditions. Data showed that particle size markedly affects the effective diameter of the drained pores active in leading gas through the sample at –100 cm H2O of soil water matric potential (calculated from Dp and ka) as well as the average pore diameter at half saturation (calculated from...

  16. Adolescent mass shootings: developmental considerations in light of the Sandy Hook shooting. (United States)

    Rice, Timothy R; Hoffman, Leon


    Adolescent mass shootings are a special subset of mass killings, which continue despite significant preventative public health efforts. It is often held that these individuals have few salient warning signs that could have been identified. This piece proposes that mass shootings committed by adolescent and post-adolescent young males must be understood from a developmental perspective. The hypothesis proposed in this paper is that such killings occur as the result of the adolescent's frustrated effort to progress along normative development. The goal of normative separation from maternal figures by the boy is presented as a potential risk factor when this goal is thwarted. Childhood case material from the perpetrator of a recent adolescent mass shooting, the Sandy Hook shooting, is discussed as an illustration of this hypothesis. Implications for public health measures and for individualized treatment are presented and developed.

  17. The macroinfauna of the Galician sandy beaches (NW Spain) affected by the Prestige oil-spill. (United States)

    Junoy, J; Castellanos, C; Viéitez, J M; de la Huz, M R; Lastra, M


    Eighteen sandy beaches were sampled along the 1659 km of the Galician coast (NW Spain) six months after the Prestige oil-spill to study the impact of the fuel and the clean-up activities on the macroinfauna community. A transect was extended at each beach, from above the drift line to below the swash line at five sampled levels; at each level six 0.05 m2 replicates were taken to a depth of 30 cm and sieved through a 1mm mesh, and the organisms collected and preserved. Results were compared with previous data obtained using the same procedures. The macroinfauna was numerically dominated by the amphipod Pontocrates arenarius, the isopod genus Eurydice, the polychaete Scolelepis squamata, and the amphipod Talitrus saltator. As a result of the Prestige oil-spill and the clean-up activities, beach populations were reduced, with Eurydice and S. squamata as the most affected taxa.

  18. Interannual Variability of Methane and Nitrous Oxide in the North Pacific Subtropical Gyre (United States)

    Wilson, Samuel T.; Ferrón, Sara; Karl, David M.


    The temporal variability of two important greenhouse gases, methane (CH4) and nitrous oxide (N2O), is reported for the upper water column at Station ALOHA in the North Pacific Subtropical Gyre. Measured concentrations of N2O conform to predicted values with an increase in saturation during the summer period. In contrast, CH4 is less predictable and shows an approximate 2 year transition from a state of oversaturation in surface waters to equilibrium values in 2015, implying a change in net CH4 production. The decrease in CH4 followed on from fluctuations in phosphate concentrations supporting the hypothesized link between microbial metabolism of phosphorus and the global biogeochemical cycle of CH4. At this current time, future trends in the net CH4 production in the North Pacific Subtropical Gyre are uncertain and specifically whether the surface ocean will be a net source or sink for CH4.

  19. Health problems among international travellers: from a subtropical region to tropical and non-tropical regions. (United States)

    Pai, Hsiu-Hua; Lai, Jin-Lin


    International travel may be associated with the risk of a wide range of infectious diseases. This study was designed to obtain information on the health problems among international travellers from a subtropical region to the neighbouring tropical, subtropical, and temperate regions. Health problems among international travellers from Taiwan to the Philippines, Malaysia, Indonesia, Singapore, Vietnam, Thailand (tropical group), Hong Kong, Macao, China and Japan (non-tropical group) were surveyed through the telephone. Of 649 travellers surveyed, 8.2% had one or more health problems and insect bite (3.4%) and coughing or sore throats (3.2%) were the most important symptoms. The rate of coughing or sore throats was significantly higher among those returned from the non-tropical regions. However, no associations were found between health problems and the demographic factors, travel style or travelling duration of travel.

  20. Rainfall reductions over Southern Hemisphere semi-arid regions: the role of subtropical dry zone expansion. (United States)

    Cai, Wenju; Cowan, Tim; Thatcher, Marcus


    Since the late 1970s, Southern Hemisphere semi-arid regions such as southern-coastal Chile, southern Africa, and southeastern Australia have experienced a drying trend in austral autumn, predominantly during April and May. The rainfall reduction coincides with a poleward expansion of the tropical belt and subtropical dry zone by around 2°-3° in the same season. This has raised questions as to whether the regional rainfall reductions are attributable to this poleward expansion. Here we show that the impact of the poleward subtropical dry-zone shift is not longitudinally uniform: a clear shift occurs south of Africa and across southern Australia, but there is no evidence of a poleward shift in the southern Chilean sector. As such, a poleward shift of climatological April-May rainfall can explain most of the southeastern Australia rainfall decline, a small portion of the southern Africa rainfall trend, but not the autumn drying over southern Chile.