WorldWideScience

Sample records for affecting soil fauna

  1. Soil fauna and organic amendment interactions affect soil carbon and crop performance in semi-arid West Africa

    OpenAIRE

    Ouédraogo, E.; Brussaard, L.; Stroosnijder, L.

    2007-01-01

    A field experiment was conducted at Kaibo in southern Burkina Faso on an Eutric Cambisol during the 2000 rainy season to assess the interaction of organic amendment quality and soil fauna, affecting soil organic carbon and sorghum ( Sorghum bicolor L. Moench) performance. Plots were treated with the pesticides Dursban and Endosulfan to exclude soil fauna or left untreated. Sub-treatments consisted of surface-placed maize straw ( C/N ratio= 58), Andropogon straw ( C/N ratio= 153), cattle dung ...

  2. Factors affecting soil fauna feeding activity in a fragmented lowland temperate deciduous woodland.

    Science.gov (United States)

    Simpson, Jake E; Slade, Eleanor; Riutta, Terhi; Taylor, Michele E

    2012-01-01

    British temperate broadleaf woodlands have been widely fragmented since the advent of modern agriculture and development. As a result, a higher proportion of woodland area is now subject to edge effects which can alter the efficiency of ecosystem functions. These areas are particularly sensitive to drought. Decomposition of detritus and nutrient cycling are driven by soil microbe and fauna coactivity. The bait lamina assay was used to assess soil fauna trophic activity in the upper soil horizons at five sites in Wytham Woods, Oxfordshire: two edge, two intermediate and one core site. Faunal trophic activity was highest in the core of the woodland, and lowest at the edge, which was correlated with a decreasing soil moisture gradient. The efficiency of the assay was tested using four different bait flavours: standardised, ash (Fraxinus excelsior L.), oak (Quercus robur L.), and sycamore (Acer pseudoplatanus L.). The standardised bait proved the most efficient flavour in terms of feeding activity. This study suggests that decomposition and nutrient cycling may be compromised in many of the UK's small, fragmented woodlands in the event of drought or climate change. PMID:22235311

  3. Soil fauna and soil functions: a jigsaw puzzle

    Directory of Open Access Journals (Sweden)

    MariaJ.I.Briones

    2014-04-01

    Full Text Available Terrestrial ecologists and soil modelers have traditionally portrayed the inhabitants of soil as a black box labeled as "soil fauna" or "decomposers or detritivores” assuming that they just merely recycle the deposited dead plant material. Soil is one of the most diverse habitats on Earth and contains one of the most diverse assemblages of living organisms; however, the opacity of this world has severely limited our understanding of their functional contributions to soil processes and to ecosystem resilience. Traditional taxonomy, based on morphological and anatomical aspects, is becoming replaced by rapid processing molecular techniques (e.g. with marker gene-based approaches. However, this may be impracticable in many ecological studies and consequently, the majority of the current knowledge, still contributes little to our understanding of their role in ecosystem functioning. Over the years, different workers have produced several ‘functional classifications’ based on the body width, feeding regime, certain behavioral and reproductive aspects and ecological niches of soil organisms. Unfortunately, the information available is severely restricted to ‘major’ groups. A better physiological and metabolic understanding of when and how a complex community of soil organisms access nutrients, alter their environment and in turn, affect soil processes, will allow a more realistic quantitative evaluation of their ecological roles in the biogeochemical cycles. Here, I review the applicability of the available approaches, highlight future research challenges and propose a dynamic conceptual framework that could improve our ability to solve this functional puzzle.

  4. SOIL FAUNA CHARACTERIZATION IN Eucalyptus spp. PLANTATIONS

    Directory of Open Access Journals (Sweden)

    Juliana Garlet

    2013-08-01

    Full Text Available http://dx.doi.org/10.5902/1980509810545Forest soils provide good conditions for the development and the establishment of soil fauna, manly by the deposition of litter. However, monoculture systems conducted in a single substrate by providing food, can promote the development of certain animal groups over others, causing outbreaks of pest species. The aim of this study was to characterize the soil fauna and its relationship with meteorological variables, in plantations of Eucalyptus spp. This study was conducted in six stands of Eucalyptus from three species: Eucalyptus dunni Maiden, Eucalyptus grandis Maiden and Eucalyptus grandis x Eucalyptus urophylla S. T. Blake (clone hybrid and two ages (planted in 2006 and 2007.

  5. On the contribution of the soil fauna to the macropores

    Science.gov (United States)

    Barontini, Stefano; Vitale, Paolo; Comincini, Mattia; Pezzotti, Dario; Peli, Marco; Armiraglio, Stefano; Tomirotti, Massimo; Ranzi, Roberto

    2016-04-01

    Soil fauna play an important role in characterizing the soil structure, and they are one of the main macropore sources, together with roots, swelling and local erosion. In an hydrological perspective, according to most of the authors, macropores are meati with meaningfully small capillary action, that is with a characteristic transverse-length greater than some tens of micrometers. Macropores importance is crucial for the hydrological cycle, as they are seat of preferential flow and they contribute to key hydrological processes, viz infiltration, percolation and subsurface runoff. In the framework of a wider investigation which aims at deepening the comprehension of the role played by the macropores in characterising the soil hydrological response (at spatial scales from the local to the slope one), we present a literature reanalysis focused on the capability of soil fauna to dig nests, holes, burrows, and subsoil tunnels and rooms. Particularly we examinated data about fauna with dimensions ranging from small arthropods and anellids to some big chordates. As a result we present a classification approach which aims at enlightening the hydrological features of the holes, e.g. structure, length, main direction, tortuosity, transverse section, displaced soil volume, hydraulic radius, digging technique, affected soil layers, in view of comparing the hydrological fallouts of different soil diggers.

  6. The effect of soil fauna on carbon sequestration in soil

    Czech Academy of Sciences Publication Activity Database

    Frouz, Jan; Pižl, Václav; Kaneda, Satoshi; Šimek, Miloslav

    2008-01-01

    Roč. 10, - (2008). ISSN 1029-7006. [EGU General Assembly 2008. 13.04.2008-18.04.2008, Vienna] Institutional research plan: CEZ:AV0Z60660521 Keywords : soil fauna * carbon sequestration * soil Subject RIV: EH - Ecology, Behaviour

  7. SOIL FAUNA CHARACTERIZATION IN Eucalyptus spp. PLANTATIONS

    OpenAIRE

    Juliana Garlet; Ervandil Correa Costa; Jardel Boscardin

    2013-01-01

    http://dx.doi.org/10.5902/1980509810545Forest soils provide good conditions for the development and the establishment of soil fauna, manly by the deposition of litter. However, monoculture systems conducted in a single substrate by providing food, can promote the development of certain animal groups over others, causing outbreaks of pest species. The aim of this study was to characterize the soil fauna and its relationship with meteorological variables, in plantations of Eucalyptus spp. This ...

  8. Community structures of soil fauna in reclaimed copper mine tailings and suburb forest land

    Directory of Open Access Journals (Sweden)

    Yongheng Zhu

    2012-11-01

    Full Text Available Soil fauna were very important for the ecological reconstruction of mine tailings. We investigated community characteristics of soil fauna at two sites, including reclamated copper-mine-tailings (RCMT and suburb forest land of reclamated copper-mine-tailings (SFL in Tongling City to test and illustrate the value of soil fauna for mitigating the impacts of heavy metal pollution. In the spring of 2011, we established four transects (150 m at the two sites and collected soil samples of macro-, meso- and micro- soil fauna from four depths (0–5 cm, 5–10 cm, 10–15 cm, 15–20 cm at 13 30 cm× 30 cm sampling quadrats. Our results showed that at RCMT, the Acarina, Collembola and Nematoda were dominant groups; the Formicidae, Coleoptera larvae, Oligochaeta, Diptera larvae and Diplura were frequent groups; and the additional 16 groups were less commonly encountered. While at SFL the Collembola and Acarina were dominant groups and the Nematoda and Oligochaeta were frequent groups. Overall abundance of soil fauna at RCMT were significantly less than that of SFL (F=20.65, P<0.01, and number of faunal groups were lower at RCMT (F=5.88, P<0.05. We did not find a significant difference between the density of macro-soil fauna at RCMT and SFL, but found that the density of meso- and micro- soil fauna at RCMT was significantly lower than that of SFL (F=29.99, P<0.01. The Shannon-Wiener diversity index (H at RCMT was higher than that of SFL (F=24.06, P<0.01, but DG diversity index was lower at RCMT compared to SFL (F=4.75, P<0.05. There was evident surface aggregation of soil fauna at RCMT, especially in the differences between the first layer and the other layers of the soil profile (Find.=17.80, Fgro.=33.33, P<0.01. Redundancy analysis indicated that soil macro-, dry-type, wet-type meso- and micro-fauna at different habitats were differentially affected by various environmental factors. At reclaimed land with higher copper concentrations, we found a higher

  9. Effects of of Habitats and Pesticides on Aerobic Capacity and Survival of Soil Fauna

    Institute of Scientific and Technical Information of China (English)

    G. TRIPATHI; B. M. SHARMA

    2005-01-01

    arthropods as well as total soil fauna. Acari was least affected by γ-BHC and maximally affected (72%) in response to quinalphos. The effect of γ-BHC was fairly similar on Coleoptera, Collembola, other arthropod and total soil fauna suggesting almost similar sensitivity to this pesticide. Likewise, quinalphos was similarly effective on Collemobola and other soil arthropods. Application of carbaryl decreased Acari and Coleoptera population but increased Collembola, other arthropods and total faunal populations. However, application of cypermethrin significantly reduced the population of Acari, Coleoptera, Collembola and total soil fauna and increased the population of other soil arthropods. In both the cases, acarine population was least affected. Conclusion The observations show the habitat-specific variation in aerobic capacity of soil fauna. However, pesticide-dependent loss in population might be due to impairment of aerobic capacity of soil inhabiting animals in desert.

  10. Preliminary Response of Soil Fauna to Simulated N Deposition in Three Typical Subtropical Forests

    Institute of Scientific and Technical Information of China (English)

    XU Guo-Liang; MO Jiang-Ming; ZHOU Guo-Yi; FU Sheng-Lei

    2006-01-01

    A field-scale experiment arranged in a complete randomized block design with three N addition treatments including a control (no addition of N), a low N (5 g m-2 year-1), and a medium N (10 g m-2 year-1) was performed in each of the three typical forests, a pine (Pinus massoniana Lamb.) forest (PF), a pine-broadleaf mixed forest (MF) and a mature monsoon evergreen broadleaf forest (MEBF), of the Dinghushan Biosphere Reserve in subtropical China to study the response of soil fauna community to additions of N. Higher NH4+ and NO3- concentrations and a lower soil pH occurred in the medium N treatment of MEBF, whereas the NO3- concentration was the lowest in PF after the additions of N. The response of the density, group abundance and diversity index of soil fauna to addition of N varied with the forest type,and all these variables decreased with increasing N under MEBF but the trend was opposite under PF. The N treatments had no significant effects on these variables under MF. Compared with the control plots, the medium N treatment had significant negative effect on soil fauna under MEBF. The group abundance of soil fauna increased significantly with additions of higher N rates under PF. These results suggested that the response of soil fauna to N deposition varied with the forest type and N deposition rate, and soil N status is one of the important factors affecting the response of soil fauna to N deposition.

  11. CHARACTERIZATION OF SOIL AND LITTER FAUNA IN DIFFERENT COCOA AGROECOSYSTEMS

    Science.gov (United States)

    The objective of this study was to characterize the density and diversity of meso and macro-fauna of soils located under cacao agrosystems of southern Bahia, Brazil. The researched areas studied were: Cacao improved with Erythrina spp. shade tree (CRE); Cacao under an improved cabruca (CRC); Cacao ...

  12. Climate and litter quality differently modulate the effects of soil fauna on litter decomposition across biomes

    OpenAIRE

    García-Palacios, Pablo; Maestre, Fernando T.; Kattge, Jens; Wall, Diana H.

    2013-01-01

    Climate and litter quality have been identified as major drivers of litter decomposition at large spatial scales. However, the role played by soil fauna remains largely unknown, despite its importance for litter fragmentation and microbial activity. We synthesized litterbag studies to quantify the effect sizes of soil fauna on litter decomposition rates at the global and biome scales, and to assess how climate, litter quality and soil fauna interact to determine such rates. Soil fauna consist...

  13. EFFECTS OF SOIL FAUNA ON LITTER DECOMPOSITION

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Forest litter is the physical makeup part of forest ecosystem. The rate of decomposition of forest litter is low in temperate and cool temperate zones. There is important significance to search and utilize the function of soil animals, in order to probe the material circulation and energy flow in forest ecosystem. We selected three kinds of mesh bag with different mesh size, in which, large pore mesh bag is large enough to permit the activities of all kinds of soil animals, medium mesh bag is designed to exclude the function of soil macrofauna, while small mesh bag is small enough to exclude the effects of any kind of soil animals as far as possible. The decomposition time is three years. The studying results show that: the decomposing speed of the bags with big meshes, under functions of all kinds of soil animals, faster than the bags with medium meshes, under functions of medium and small soil animals, as well as the bags with small meshes that excluding all possibility of functions of soil animals; in the process of decomposition of litter, relationship of the litter lost weight with number of soil animals is not obvious clearly; the degree of functions of soil animals to soft litter higher than hard litter; according to the analysis of diversity index, no regular changes will happen to the diversity of soil animals as the time of decomposing samples lengthen.

  14. Soil fauna research in Poland: earthworms (Lumbricidae

    Directory of Open Access Journals (Sweden)

    Pączka Grzegorz

    2015-06-01

    Full Text Available Living organisms are the foundation of ecosystem services. Of particular notice is zooedaphone, often underestimated and basically unknown to the general public. The present review summarizes the current state of knowledge related to earthworms occurring in natural and anthropogenically altered habitats in Poland, in the context of the requirement for protection of soil biodiversity.

  15. Impact of agricultural practices on selected soil decomposers fauna

    International Nuclear Information System (INIS)

    Soil decomposers fauna i.e. collembolan, mites and nematodes were studied and compared between and within sites in relation to site, treatment and time of collection in Shambat arable and El Rwakeeb dry land. Comparison of results between sites showed that population density/volume of decomposers fauna sampled from Shambat site exceeded their assemblages sampled from El Rawakeeb site. Treatment application in form of cattle manure and neem leaves powder were observed to induce insignificant changes in the three faunal groups between the two sites. Temporal variations showed significant annual variations and insignificant seasonal variations between the two sites. Within each site, population density/volume of each of collembolan, mites and nematodes increased in response to cattle manure application in both sites. Whereas, neem leaves powder application induced a significant decrease in population density/volume of collembola in both sites. These results are generally attributed to variability of soil properties which may add to the suitability of Shambat soil to El Rawakeeb one for the survival of decomposers fauna. Within each site, increase in population density/volume of these fauna upon cattle manure application was attributed to ability of cattle manure to improve soil properties and to provide food. The negative effect of neem leaves powder on mites and nematodes was attributed to neem toxicity, whereas, its positive effects on collembolan was attributed to the ability of collembolan to withstand neem toxicity, collembolan probably physiologically resistant and the neem powder provided food, thus increasing its numbers compared to the central treatment.(Author)

  16. No adverse effect of genetically modified antifungal wheat on decomposition dynamics and the soil fauna community--a field study.

    Directory of Open Access Journals (Sweden)

    Caroline Duc

    Full Text Available The cultivation of genetically modified (GM plants has raised several environmental concerns. One of these concerns regards non-target soil fauna organisms, which play an important role in the decomposition of organic matter and hence are largely exposed to GM plant residues. Soil fauna may be directly affected by transgene products or indirectly by pleiotropic effects such as a modified plant metabolism. Thus, ecosystem services and functioning might be affected negatively. In a litterbag experiment in the field we analysed the decomposition process and the soil fauna community involved. Therefore, we used four experimental GM wheat varieties, two with a race-specific antifungal resistance against powdery mildew (Pm3b and two with an unspecific antifungal resistance based on the expression of chitinase and glucanase. We compared them with two non-GM isolines and six conventional cereal varieties. To elucidate the mechanisms that cause differences in plant decomposition, structural plant components (i.e. C∶N ratio, lignin, cellulose, hemicellulose were examined and soil properties, temperature and precipitation were monitored. The most frequent taxa extracted from decaying plant material were mites (Cryptostigmata, Gamasina and Uropodina, springtails (Isotomidae, annelids (Enchytraeidae and Diptera (Cecidomyiidae larvae. Despite a single significant transgenic/month interaction for Cecidomyiidae larvae, which is probably random, we detected no impact of the GM wheat on the soil fauna community. However, soil fauna differences among conventional cereal varieties were more pronounced than between GM and non-GM wheat. While leaf residue decomposition in GM and non-GM wheat was similar, differences among conventional cereals were evident. Furthermore, sampling date and location were found to greatly influence soil fauna community and decomposition processes. The results give no indication of ecologically relevant adverse effects of antifungal GM

  17. Does soil fauna increase carbon mineralization or carbon sequestration in soil

    Czech Academy of Sciences Publication Activity Database

    Frouz, Jan

    České Budějovice : Institute of Soil Biology BC AS CR, 2009. s. 22. [Central European Workshop on Soil Zoology /10./. 21.04.2009-24.04.2009, České Budějovice] Institutional research plan: CEZ:AV0Z60660521 Keywords : soil fauna * carbon mineralization * carbon sequestration Subject RIV: EH - Ecology, Behaviour

  18. Soil fauna communities and microbial respiration in high Arctic tundra soils at Zackenberg, Northeast Greenland

    DEFF Research Database (Denmark)

    Sørensen, Louise I.; Holmstrup, Martin; Maraldo, Kristine;

    2006-01-01

    The soil fauna communities were described for three dominant vegetation types in a high arctic site at Zackenberg, Northeast Greenland. Soil samples were extracted to quantify the densities of mites, collembolans, enchytraeids, diptera larvae, nematodes and protozoa. Rates of microbial respiration...... were also assessed. Collembolans were found in highest densities in dry heath soil, about 130,000 individuals m-2, more than twice as high as in mesic heath soils. Enchytraeids, diptera larvae and nematodes were also more abundant in the dry heath soil than in mesic heath soils, whereas protozoan...... densities (naked amoeba and heterotrophic flagellates) were equal. Respiration rate of unamended soil was similar in soil from the three plots. However, a higher respiration rate increase in carbon + nutrient amended soil and the higher densities of soil fauna (with the exception of mites and protozoa) in...

  19. Fauna inhibit nitrogen mineralization in no-tilled soil, but not in tilled soil

    Czech Academy of Sciences Publication Activity Database

    Toyota, Ayu; Frouz, Jan; Hynšt, Jaroslav

    České Budějovice : Institute of Soil Biology, BC ASCR, 2011. s. 49. ISBN 978-80-86525-19-8. [Central European Workshop on Soil Zoology /11./. 11.04.2011-14.04.2011, České Budějovice] Institutional research plan: CEZ:AV0Z60660521 Keywords : soil fauna * nitrogen mineralization * no-tilled soil Subject RIV: EH - Ecology, Behaviour

  20. Contrasting effects of soil fauna on the nitrogen dynamics of tillage and no-tillage soils

    Czech Academy of Sciences Publication Activity Database

    Toyota, Ayu; Frouz, Jan; Hynšt, Jaroslav

    Xalapa : Instituto de Ecología, A.C, 2010. s. 153. [International Symposium on Earthworm Ecology /9./. 05.09.2010-10.09.2010, Xalapa] Institutional research plan: CEZ:AV0Z60660521 Keywords : soil fauna * nitrogen dynamics * tillage and no-tillage soils Subject RIV: EH - Ecology, Behaviour

  1. Soil and freshwater nematodes of the Iberian fauna: A synthesis

    Directory of Open Access Journals (Sweden)

    Peña-Santiago, R.

    2006-12-01

    Full Text Available The first available compilation of Iberian soil and freshwater nematodes is presented in this paper. The inventory is currently made up of 981 species belonging to 236 genera, 77 families and 12 orders. Data of the Iberian nematode fauna are compared with other components of the Iberian biota, as well as the nematode fauna of other geographical regions. Quantitative and qualitative aspects of the nematode inventory are analyzed and discussed, paying special attention to the kind of information available for each species, and concluding that practically one-third of Iberian species are deficiently characterized and need further study. Endemicity of Iberian species is also considered: 143 species, 14.6% of the total, are restricted (in their distribution to the Iberian geography, most of them being members of the orders Dorylaimida (87 and Tylenchida (29, which are also the most diversified nematode taxa. Practical or applied interest of knowledge of the Iberian nematode fauna is commented and supported with examples and recent contributions. Finally, an alphabetical list of the species, ordered by specific name, is provided.

    En esta contribución se presenta una recopilación de las especies ibéricas de nematodos de suelo y de agua dulce, la primera de este tipo realizada hasta el momento. El inventario actual lo componen 981 especies de 236 géneros, 77 familias y 12 órdenes. Los datos correspondiente a la fauna ibérica de nematodos se compara con la de otros táxones de la biota ibérica. Se analizan y se discuten distintos aspectos cuantitativos y cualitativos de la fauna nematológica, con especial énfasis en el tipo de información disponible sobre cada especie, y se concluye que casi una tercera parte de las especies ibéricas permanecen insuficientemente caracterizadas, razón por la cual requieren de estudios adicionales. La endemicidad de las especies es así mismo objeto de atención: 143 especies, un 14.6% del total est

  2. Soil salinization as a stress factor for soil fauna

    OpenAIRE

    Duarte, Gabriel Alexandre Isidoro

    2011-01-01

    A existência de condições desfavoráveis no solo (p.e. um agente químico) pode influenciar a presença de organismos de solo ou parâmetros do ciclo de vida tais como a reprodução da fauna do solo num local específico. Logo, a resposta de evitamento e o sucesso reprodutivo de organismos em locais contaminados pode ser utilizada como uma primeira ferramenta de avaliação de risco ecológico, já que respostas negativas de evitamento ou reprodução significam que deverá haver algum...

  3. Dynamics of Soil Fauna in Da Hinggan Mountains, Northeast China

    Institute of Scientific and Technical Information of China (English)

    ZHANG Xueping; SUN Yuan; HUANG Lirong

    2009-01-01

    The dynamics of soil animals was studied in seven representative forest communities in the north of the Da Hinggan Mountains, Northeast China. The results indicate that it was distinctive in the changes of the numbers of soil animals and groups and diversity in relationship with seasons for macrofauna and torso-micro fauna in the study area. The numbers of the observed soil animals in different months were: October>August>June. Group number was larger in August and October, but smaller in June. The change of diversity index in different months was: August>June>October. The biomass for macrofanna in different months was: October>June>August. The composition and number of each functional group was relatively stable. In the community of the predominant soil environment, the percentage of saprophagous animals was higher than carnivorous animals and herbivorous animals. The dynamics changes of saprophagous and carnivorous animals were distinctive, increasing from June to October, while the change of herbivorous animals was unremarkable.

  4. Soil tillage, physical disturbance and fauna population: a case study in western Iran

    Science.gov (United States)

    Moradi, Jabbar

    2015-04-01

    As a vital biological habitat for a great number of organisms and a medium for soil food web, soil has a great importance in regulating the two main life-supporting processes: production and decomposition. For more sustainable agricultural systems, understanding the mechanisms shaping soil fauna populations is of great importance specially in semi-arid regions with low organic matter soils. In this regard a two year study in 2008 and 2009 was conducted in western Iran to see the consequences of implementing three different tillage systems (conventional, minimum and no tillage) and three levels of organic matter amendment (0, 20 and 40 ton.ha-1 of cattle manure) over the population of soil fauna (i.e. earthworms, mite, springtail and nematodes) in three different sampling periods each year. In the second year BD decreased in the tillage treatments with mechanical turmoil but seems it started to increase in conventional tillage that can be due to higher decomposition of organic matter as the result of aeration and mixing of organic matter with the soil but shows a decrease pattern for the other two which can be due to less and no disturbance and as a result less elimination of soil aggregates. Observed earthworm populations were low besides of their patchy distribution that made the numbers unreliable to be interpreted. Soil mites showed no change regarding to treatments implemented which highlighted the importance of the need to observations in the suborder level and some other environmental variables. Soil springtails were reduced by soil tillage indicating their sensitivity to the disturbance in their physical habitat. Nematodes were mainly affected by organic matter. They showed an increase in their population (113 N.100g soil-1) in 2008 with application of 40 ton.ha-1 of cattle manure but in the second year because of the remaining effects of cattle manure the changes has been observed in response to the disturbance induced by tillage with the lowest numbers in

  5. Microelement contents of litter, soil fauna and soil in Pinus koralensis and mixed broad-leaved forest

    Institute of Scientific and Technical Information of China (English)

    LI Jinxia; YIN Xiuqin; DONG Weihua

    2007-01-01

    The Mn,Zn and Cu contents of litter,soil fauna and soil in Pinus koraiensis and mixed broad-leaved forest in Liangshui Nature Reserve of Xiaoxing'an Mountains were analyzed in this paper,results showed that the tested microelement contents in the litter,soil fauna and soil followed the order:Mn>Zn>Cu,but varied with environmental components,for Mn the order is soil>litter>soil fauna,for Zn is soil fauna>litter and soil,and for Cu is soil fauna>soil>litter.The change range of the tested microelement contents in litter was larger in broad-leaved forest than those in coniferous forest.Different soil fauna differed in their microelementenrichment capability,the highest content of Mn,Zn and Cu existed in earthworm,centipede and diplopod,respectively.The contents of the tested microelements in soil fauna had significant correlations with their environmental background values,litter decomposition rate,food habit of soil fauna,and its absorbing selectively and enrichment to microelements.The microelements contained in 5-20 cm soil horizon were more than those in 0-5 cm humus layer,and their dynamics differed in various horizons.

  6. Soil fauna in forest and coffee plantations from the Sierra Nevada de Santa Mar ta, Colombia

    International Nuclear Information System (INIS)

    Two research stations (M inca, 700 m altitude and Maria Ter esa, 790 m altitude) were established in the Sierra Nevada de Santa Mar ta in places to study the soil fauna associated with forest and coffee plantations. Soil fauna was collected using pitfall and Bailer's traps. Samples were taken from litter as well as from horizons 0, A and B. individuals collected were identified to family level. Diversity, abundance and frequency indexes were used to compare fauna composition at both sites. Significant differences were found between the two research sites as well as with data from other high altitude forest in the Sierra Nevada de Santa Mar ta

  7. Do high ungulate densities stress soil fauna in temperate forest ecosystems?

    Czech Academy of Sciences Publication Activity Database

    Tajovský, Karel; Pižl, Václav; Háněl, Ladislav; Starý, Josef; Frouz, Jan; Aurová, Klára; Kalčík, Jiří

    Curitiba : Positivo University, 2008. [Biodiversity, Conservation and Sustainable Management of Soil Animals. International Colloquium on Soil Zoology /15./. 25.08.2008-29.08.2008, Curitiba] R&D Projects: GA ČR(CZ) GA526/06/1348 Institutional research plan: CEZ:AV0Z60660521 Keywords : ungulate densities * soil fauna * temperate forest ecosystems Subject RIV: EH - Ecology, Behaviour

  8. Do soil macro-fauna and micro-flora interact synergistically in leaf litter decomposition?

    Czech Academy of Sciences Publication Activity Database

    Špaldoňová, Alexandra; Frouz, Jan

    Coimbra: University of Coimbra, 2012. s. 181. [International Colloquium on Soil Zoology /16./. 06.08.2012-10.08.2012, Coimbra] Institutional support: RVO:60077344 Keywords : soil macro-fauna * soil micro-flora * leaf litter decomposition Subject RIV: EH - Ecology, Behaviour

  9. Soil fauna abundance and diversity in a secondary semi-evergreen forest in Guadeloupe (Lesser Antilles): influence of soil type and dominant tree species

    OpenAIRE

    Loranger-Merciris, Gladys; Imbert, Daniel; Bernhard-Reversat, France; PONGE, Jean-François; Lavelle, Patrick

    2007-01-01

    International audience The importance of secondary tropical forests regarding the maintenance of soil fauna abundance and diversity is poorly known. The aims of this study were (1) to describe soil fauna abundance and diversity and (2) to assess the determinants of soil fauna abundance and diversity in two stands of a tropical semi-evergreen secondary forest. Soil macrofauna and microarthropod abundance and soil macrofauna diversity were described at two sites developed on different soils ...

  10. Microbial biomass and soil fauna during the decomposition of cover crops in no-tillage system

    Directory of Open Access Journals (Sweden)

    Luciano Colpo Gatiboni

    2011-08-01

    Full Text Available The decomposition of plant residues is a biological process mediated by soil fauna, but few studies have been done evaluating its dynamics in time during the process of disappearance of straw. This study was carried out in Chapecó, in southern Brazil, with the objective of monitoring modifications in soil fauna populations and the C content in the soil microbial biomass (C SMB during the decomposition of winter cover crop residues in a no-till system. The following treatments were tested: 1 Black oat straw (Avena strigosa Schreb.; 2 Rye straw (Secale cereale L.; 3 Common vetch straw (Vicia sativa L.. The cover crops were grown until full flowering and then cut mechanically with a rolling stalk chopper. The soil fauna and C content in soil microbial biomass (C SMB were assessed during the period of straw decomposition, from October 2006 to February 2007. To evaluate C SMB by the irradiation-extraction method, soil samples from the 0-10 cm layer were used, collected on eight dates, from before until 100 days after residue chopping. The soil fauna was collected with pitfall traps on seven dates up to 85 days after residue chopping. The phytomass decomposition of common vetch was faster than of black oat and rye residues. The C SMB decreased during the process of straw decomposition, fastest in the treatment with common vetch. In the common vetch treatment, the diversity of the soil fauna was reduced at the end of the decomposition process.

  11. Fauna-associated Changes in Chemical and Biochemical Properties of Soil

    Institute of Scientific and Technical Information of China (English)

    G. TRIPATHI; B. M. SHARMA

    2006-01-01

    Objective To study the impacts of abundance of woodlice, termites, and mites on some functional aspects of soil in order to elucidate the specific role of soil fauna in improving soil fertility in desert. Methods Fauna-rich sites were selected as experimental sites and adjacent areas were taken as control. Soil samples were collected from both sites. Soil respiration was measured at both sites. The soil samples were sent to laboratory, their chemical and biochemical properties were analyzed.Results Woodlice showed 25% decrease in organic carbon and organic matter as compared to control site. Whereas termites and mites showed 58% and 16% decrease in organic carbon and organic matter. In contrast, available nitrogen (nitrate and ammonical both) and phosphorus exhibited 2-fold and 1.2-fold increase, respectively. Soil respiration and dehydrogenase activity at the sites rich in woodlice, termites and mites produced 2.5-, 3.5- and 2-fold increases, respectively as compared to their control values. Fauna-associated increase in these biological parameters clearly reflected fauna-induced microbial activity in soil. Maximum decrease in organic carbon and increase in nitrate-nitrogen and ammonical-nitrogen, available phosphorus, soil respiration and dehydrogenase activity were produced by termites and minimum by mites reflecting termite as an efficient soil improver in desert environment. Conclusion The soil fauna-associated changes in chemical (organic carbon, nitrate-nitrogen, ammonical-nitrogen, phosphorus) and biochemical (soil respiration, dehydrogenase activity) properties of soil improve soil health and help in conservation of desert pedoecosystem.

  12. Quantification of soil fauna metabolites and dead mass as humification sources in forest soils

    Science.gov (United States)

    Chertov, O. G.

    2016-01-01

    The analysis of publications on soil food webs (FWs) allowed calculation of the contents of soil fauna metabolites and dead mass, which can serve as materials for humification. Excreta production of FWmicrofauna reaches 570 kg/ha annually, but the liquid excreta of protozoa and nematodes compose about 25%. The soil fauna dead mass can be also maximally about 580 kg/ha per year. However, up to 70% of this material is a dead mass of bacteria, protozoa, and nematodes. The undecomposed forest floor (L) has low values of these metabolites in comparison with the raw humus organic layer (F + H). The mass of these metabolites is twice lower in Ah. Theoretical assessment of earthworms' role in SOM formation shows that the SOM amount in fresh coprolites can be 1.4 to 4.5-fold higher than SOM in the bulk soil in dependence on food assimilation efficiency, the soil: litter ratio in the earthworms' ration, and SOM quantity in the bulk soil. Excreta production varies from 0.2 to 1.9% of the total SOM pool annually, including 0.15-1.5% of excrements of arthropods and enchytraeidae, but the amount of arthropods' dead mass comprises 0.2-0.4%. The calculated values of the SOM increase due to earthworms' coprolites are of the same order (0.9-2.7% of SOM pool annually). These values of SOM-forming biota metabolites and dead mass are close to the experimental and simulated data on labile and stable SOM fractions decomposition in forest soils (about 2% annually). Therefore, these biota's products can play a role to restock SOM decrease due to mineralization.

  13. Characterization of soil fauna under the influence of mercury atmospheric deposition in Atlantic Forest, Rio de Janeiro, Brazil.

    Science.gov (United States)

    Buch, Andressa Cristhy; Correia, Maria Elizabeth Fernandes; Teixeira, Daniel Cabral; Silva-Filho, Emmanoel Vieira

    2015-06-01

    The increasing levels of mercury (Hg) found in the atmosphere arising from anthropogenic sources, have been the object of great concern in the past two decades in industrialized countries. Brazil is the seventh country with the highest rate of mercury in the atmosphere. The major input of Hg to ecosystems is through atmospheric deposition (wet and dry), being transported in the atmosphere over large distances. The forest biomes are of strong importance in the atmosphere/soil cycling of elemental Hg through foliar uptake and subsequent transference to the soil through litter, playing an important role as sink of this element. Soil microarthropods are keys to understanding the soil ecosystem, and for such purpose were characterized by the soil fauna of two Units of Forest Conservation of the state of the Rio de Janeiro, inwhich one of the areas suffer quite interference from petrochemicals and industrial anthropogenic activities and other area almost exempts of these perturbations. The results showed that soil and litter of the Atlantic Forest in Brazil tend to stock high mercury concentrations, which could affect the abundance and richness of soil fauna, endangering its biodiversity and thereby the functioning of ecosystems. PMID:26040748

  14. Contribution of soil fauna to soil functioning in degraded environments: a multidisciplinary approach

    Science.gov (United States)

    Gargiulo, Laura; Mele, Giacomo; Moradi, Jabbar; Kukla, Jaroslav; Jandová, Kateřina; Frouz, Jan

    2016-04-01

    The restoration of the soil functions is essential for the recovery of highly degraded sites and, consequently, the study of the soil fauna role in the soil development in such environments has great potential from a practical point of view. The soils of the post-mining sites represent unique models for the study of the natural ecological succession because mining creates similar environments characterized by the same substrate, but by different ages according to the year of closure of mines. The aim of this work was to assess the contribution of different species of macrofauna on the evolution of soil structure and on the composition and activity of the microbial community in soil samples subjected to ecological restoration or characterized by spontaneous ecological succession. For this purpose, an experimental test was carried out in two sites characterized by different post-mining conditions: 1) natural succession, 2) reclamation with planting trees. These sites are located in the post-mining area of Sokolov (Czech Republic). For the experimental test repacked soil cores were prepared in laboratory with sieved soil sampled from the two sites. The soil cores were prepared maintaining the sequence of soil horizons present in the field. These samples were inoculated separately with two genera of earthworms (Lumbricus and Aporrectodea) and two of centipedes (Julida and Polydesmus). In particular, based on their body size, were inoculated for each cylinder 2 individuals of millipedes, 1 individual of Lumbricus and 4 individuals of Aporrectodea. For each treatment and for control samples 5 replicates were prepared and all samples were incubated in field for 1 month in the two original sampling sites. After the incubation the samples were removed from the field and transported in laboratory in order to perform the analysis of microbial respiration, of PLFA (phospholipid-derived fatty acids) and ergosterol contents and finally for the characterization of soil structure

  15. Insect fauna in soil at different grassland ecosystems at Sobral, state of Ceará, Brazil

    OpenAIRE

    Gislane dos Santos Sousa; Silvia Cristenia da Silva Xavier; Petronio Emanuel Timbó Braga

    2013-01-01

    The aim of this study was perform a surveillance of the insect fauna in soil in three grassland ecosystems of experimental farm Vale do Acaraú of Universidade Estadual Vale do Acaraú at Sobral, state of Ceará, Brazil, by the using of traps soil, with fortnightly collections, from March 2011 to February 2012. To characterize the insect fauna established a distribution pattern, whereas the rates of occurrence and dominance of species grouped by order, as an indicator of the frequency and the oc...

  16. Theory of ecological resilience and their application to soil fauna studies

    Czech Academy of Sciences Publication Activity Database

    Sterzyńska, M.; Nicia, P.; Pižl, Václav; Starý, Josef; Tajovský, Karel

    České Budějovice : Institute of Soil Biology, BC ASCR, 2013. s. 54. ISBN 978-80-86525-23-5. [Central European Workshop on Soil Zoology /12./. 08.04.2013-11.04.2013, České Budějovice] Grant ostatní: National Science Center(PL) 1562/B/p01/2011/40 Institutional support: RVO:60077344 Keywords : ecological resilience * soil fauna Subject RIV: EH - Ecology, Behaviour

  17. The invertebrate fauna of anthropogenic soils in the High-Arctic settlement of Barentsburg, Svalbard

    Directory of Open Access Journals (Sweden)

    Torstein Solhøy

    2013-05-01

    Full Text Available The terrestrial environment of the High Arctic consists of a mosaic of habitat types. In addition to the natural habitat diversity, various human-influenced types may occur. For the resident invertebrate fauna, these anthropogenic habitats may be either unusually favourable or detrimental. In the town of Barentsburg, Svalbard, soils were imported for the greenhouses from southern Russia. These soils were subsequently discarded outside the greenhouses and have become augmented with manure from the cowsheds. Both the greenhouse and the cowsheds are now derelict. This site represents an unusually nutrient-rich location with considerable development of organic soils, in stark contrast to the naturally forming organic soils in Svalbard, which are typically thin and nutrient poor. Few previous studies have examined the soil invertebrate communities of human-disturbed or -created habitats in the Arctic. In an often nutrient-poor terrestrial environment, it is unclear how the invertebrate fauna will react to such nutrient enhancement. In these soils, 46 species of invertebrates were determined. Eleven species have not been recorded from other habitats in Svalbard and are hence likely to have been introduced. The native species assemblage in the anthropogenic soils was not atypical for many natural sites in Svalbard. Despite the enriched organic soils and highly ameliorated winter temperature conditions, the soil invertebrate fauna biodiversity does not appear to be enhanced beyond the presence of certain probably introduced species.

  18. Response of soil fauna to simulated nitrogen deposition: A nursery experiment in Subtropical China

    Institute of Scientific and Technical Information of China (English)

    XU Guo-liang; MO Jiang-ming; FU Sheng-lei; PER Gundersen; ZHOU Guo-yi; XUE Jing-Hua

    2007-01-01

    We studied the responses of soil fauna to a simulated nitrogen deposition in nursery experimental plots in Subtropical China. Dissolved NH4NO3 was applied to the soil by spraying twice per month for 16 months, starting January 2003 with treatments of 0, 5, 10, 15 and 30 gN/(m2·a). Soil fauna was sampled after 6, 9, 13 and 16 months of treatment in three soil depths (0-5 cm, 5-10 cm, 10-15 cm). Soil available N increased in correspondence with the increasing N treatment, whereas soil pH decreased. Bacterial and fungal densities were elevated by the N treatment. Soil fauna increased in the lower nitrogen treatments but decreased in the higher N treatments, which might indicate that there was a threshold around 10 gN/(m2·a) for the stimulating effects of N addition. The N effects were dependent on the soil depth and sampling time. The data also suggested that the effects of the different N treatments were related to the level of N saturation, especially the concentration of NO3- in the soil.

  19. Soil fauna and diversity of animals in mining landscape of Karvina region Czech Republic

    International Nuclear Information System (INIS)

    To study development of edaphon, esp. animals living on the top of the soil-epigeon, in relation to natural succession, were utilized the extreme different habitats from devastated landscape of Karvina region, Czech republic. Using the method of ground traps was collected numerous biological material of epigeon fauna at the spoil heap of the Dukla and Lazy face working area, in Karvina region. During two years of the research 2002-2004 was collected about 20 thousand examples. The fauna of epigeon, top horizon of the soil, was recovered and determined 24 taxons. The samples were analyzed according to several ecological criteria like an abundance, dominance, diversity and frequency. Special interest was paid to the succession and biodiversity of flora and fauna of spoil heap the reclamation process. Plants and animals that are adapted to specific conditions of life. First results show that the succession of community of edaphon is faster then succession of community of plants. (author)

  20. The effect of plant diversity manipulation on the succession of soil fauna in an abandoned arable field

    Czech Academy of Sciences Publication Activity Database

    Pižl, Václav; Starý, Josef; Balík, Vladimír

    Rouen : Université de Rouen, 2004. s. 13. [International Colloquium on Soil Zoology and Ecology /14./. 30.08.2004-03.09.2004, Rouen] Keywords : plant diversity manipulation * soil fauna * abandoned arable field Subject RIV: EH - Ecology, Behaviour

  1. H.5. Impact of acidification, eutrophication, forest management and liming on soil fauna

    Czech Academy of Sciences Publication Activity Database

    Rusek, Josef

    Praha : Ministerstvo životního prostředí ČR, 2003, s. 150-156. ISBN 80-7212-190-1 Institutional research plan: CEZ:AV0Z6066911 Keywords : acidification * forest management * soil fauna Subject RIV: EH - Ecology, Behaviour

  2. The invertebrate fauna of anthropogenic soils in the High-Arctic settlement of Barentsburg, Svalbard

    OpenAIRE

    Coulson, Steve J.; Fjellberg, Arne; Dariusz J. Gwiazdowicz; Lebedeva, Natalia V.; Elena N. Melekhina; Solhøy, Torstein; Erséus, Christer; Maraldo, Kristine; Miko, Ladislav; Schatz, Heinrich; Rüdiger M. Schmelz; Søli, Geir; Stur,Elisabeth

    2013-01-01

    The terrestrial environment of the High Arctic consists of a mosaic of habitat types. In addition to the natural habitat diversity, various human-influenced types may occur. For the resident invertebrate fauna, these anthropogenic habitats may be either unusually favourable or detrimental. In the town of Barentsburg, Svalbard, soils were imported for the greenhouses from southern Russia. These soils were subsequently discarded outside the greenhouses and have become augmented with manure from...

  3. Development of soil fauna in meadows restored on arable land: Initial phases of successional development

    Czech Academy of Sciences Publication Activity Database

    Tajovský, Karel; Pižl, Václav; Starý, Josef; Balík, Vladimír; Frouz, Jan; Schlaghamerský, J.; Háněl, Ladislav; Rusek, Josef; Kalčík, Jiří

    České Budějovice : Institute of Soil Biology ASCR, 2005, s. 181-186. ISBN 80-86525-04-X. [Contributions to soil Zoology in Central Europe I. Central European Workshop on Soil Zoology /7./. České Budějovice (CZ), 14.04.2003-16.04.2003] R&D Projects: GA ČR(CZ) GA526/02/0036 Institutional research plan: CEZ:AV0Z6066911 Keywords : meadow restoration * soil fauna * succession Subject RIV: EH - Ecology, Behaviour

  4. Atmospheric deposition of mercury in Atlantic Forest and ecological risk to soil fauna

    Science.gov (United States)

    Cristhy Buch, Andressa; Cabral Teixeira, Daniel; Fernandes Correia, Maria Elizabeth; Vieira Silva-Filho, Emmanoel

    2014-05-01

    The increasing levels of mercury (Hg) found in the atmosphere nowadays has a great contribution from anthropogenic sources and has been a great concern in the past two decades in industrialized countries. Brazil is the seventh country with the highest rate of mercury in the atmosphere. Certainly, the petroleum refineries have significant contribution, seen that 100 million m3 of crude oil are annually processed. These refineries contribute with low generation of solid waste; however, a large fraction of Hg can be emitted to the atmosphere. There are sixteen refineries in Brazil, three of them located in the state of Rio de Janeiro. The Hg is a toxic and hazardous trace element, naturally found in the earth crust. The major input of Hg to ecosystems is through atmospheric deposition (wet and dry), being transported in the atmosphere over large distances. The forest biomes are of great importance in the atmosphere/soil cycling of elemental Hg through foliar uptake and subsequent transfer to the soil through litterfall, which play an important role as Hg sink. The Atlantic Forest of Brazil is the greater contributor of fauna and flora biodiversity in the world and, according to recent studies, this biome has the highest concentrations of mercury in litter in the world, as well as in China, at Subtropical Forest. Ecotoxicological assessments can predict the potential ecological risk of Hg toxicity in the soil can lead to impact the soil fauna and indirectly other trophic levels of the food chain within one or more ecosystems. This study aims to determine mercury levels that represent risks to diversity and functioning of soil fauna in tropical forest soils. The study is conducted in two forest areas inserted into conservation units of Rio de Janeiro state. One area is located next to an important petroleum refinery in activity since fifty-two years ago, whereas the other one is located next to other refinery under construction (beginning activities in 2015), which will

  5. [Composition and Density of Soil Fauna in the Region with Enhanced Radioactivity Level (Komi Republic, Vodnyi)].

    Science.gov (United States)

    Kolesnikova, A A; Kudrin, A A; Konakova, T N; Taskaeva, A A

    2015-01-01

    Studies on the influence of high levels of radiation on soil fauna were carried out in 2012 in the territory formed as a result of the activity of the enterprise for extraction and production of radium from reservoir water and waste of uranium ore from 1931 to 1956. At present the local radioactive pollution in this area is caused by the presence of heavy natural radionuclides 226Ra, 238U and products of their disintegration in soils. The oppression of soil invertebrate.fauna in pine forests and meadows with high levels of radionuclides and heavy metals is revealed. Also shown is the decrease in the number and density of different taxonomic groups of invertebrates, reduction of the diversity and spectrum of trophic groups and vital forms in the area with a high content of radionuclides in soil. Our results are in agreement with the results obtained by the similar studies showing negative influence of high-level ionizing radiation on soil fauna. PMID:26310020

  6. Is the effect of trees on soil properties mediated by soil fauna? A case study from post-mining sites

    Czech Academy of Sciences Publication Activity Database

    Frouz, J.; Livečková, M.; Albrechtová, J.; Chroňáková, Alica; Cajthaml, Tomáš; Pižl, Václav; Háněl, Ladislav; Starý, Josef; Baldrian, Petr; Lhotáková, Z.; Šimáčková, H.; Cepáková, Šárka

    2013-01-01

    Roč. 309, December (2013), s. 87-95. ISSN 0378-1127 R&D Projects: GA ČR GAP504/12/1288; GA MŠk LC06066 Institutional support: RVO:60077344 ; RVO:61388971 Keywords : bioturbation * earthworms * foliage chemistry * microorganisms * reclamation * soil fauna Subject RIV: EH - Ecology, Behaviour Impact factor: 2.667, year: 2013

  7. Altitudinal distribution of soil fauna in the Khibiny Massif

    Science.gov (United States)

    Zenkova, I. V.; Pozharskaya, V. V.; Pokhil'Ko, A. A.

    2011-09-01

    Data on the taxonomic and trophic composition, population density, and biomass of invertebrates in the soils of the main mountain vegetation zones of the Khibiny Mountains—taiga, subalpine, and alpine—are obtained. The degree of similarity between soil faunal complexes in different vegetation zones within the studied slope is higher than that between zonal biocenoses of Murmansk oblast. The mountain tundra zone differs from the zonal tundra in a higher population density and taxonomic diversity of invertebrates, which are similar to those in the northern taiga podzols. At the same time, invertebrate complexes in the mountain taiga zone are poorer than those in the zonal plain taiga soils. The analysis of invertebrate taxa present in all the studied mountain vegetation zones demonstrates similar effects of the altitudinal and latitudinal zonality on the species composition of invertebrates. A conclusion is made about a higher functional activity of saprotrophs in the high-humus soils enriched in biogenic elements of the Khibiny Mountains in comparison with the functional activity of saprotrophs in the zonal plain podzols.

  8. Effects of ivermectin application on the diversity and function of dung and soil fauna: Regulatory and scientific background information.

    Science.gov (United States)

    Adler, Nicole; Bachmann, Jean; Blanckenhorn, Wolf U; Floate, Kevin D; Jensen, John; Römbke, Jörg

    2016-08-01

    The application of veterinary medical products to livestock can impact soil organisms in manure-amended fields or adversely affect organisms that colonize dung pats of treated animals and potentially retard the degradation of dung on pastures. For this reason, the authorization process for veterinary medicinal products in the European Union includes a requirement for higher-tier tests when adverse effects on dung organisms are observed in single-species toxicity tests. However, no guidance documents for the performance of higher-tier tests are available. Hence, an international research project was undertaken to develop and validate a proposed test method under varying field conditions of climate, soil, and endemic coprophilous fauna at Lethbridge (Canada), Montpellier (France), Zurich (Switzerland), and Wageningen (The Netherlands). The specific objectives were to determine if fecal residues of an anthelmintic with known insecticidal activity (ivermectin) showed similar effects across sites on 1) insects breeding in dung of treated animals, 2) coprophilous organisms in the soil beneath the dung, and 3) rates of dung degradation. By evaluating the effects of parasiticides on communities of dung-breeding insects and soil fauna under field conditions, the test method meets the requirements of a higher-tier test as mandated by the European Union. The present study provides contextual information on authorization requirements for veterinary medicinal products and on the structure and function of dung and soil organism communities. It also provides a summary of the main findings. Subsequent studies on this issue provide detailed information on different aspects of this overall project. Environ Toxicol Chem 2016;35:1914-1923. © 2015 SETAC. PMID:26573955

  9. How does litter cover, litter diversity and fauna affect sediment discharge and runoff?

    Science.gov (United States)

    Goebes, Philipp; Seitz, Steffen; Kühn, Peter; Scholten, Thomas

    2013-04-01

    Litter cover plays a major role in soil erosion processes. It is known that litter cover reduces erosivity of raindrops, decreases sediment discharge and lowers runoff volume compared to bare ground. However, in the context of biodiversity, the composition of litter cover, its effect on sediment discharge and runoff volume and their influence on soil erosion have not yet been analyzed in detail. Focusing on initial soil erosion (splash), our experimental design is designated to get a better understanding of these mechanisms. The experiments were carried out within the DFG research unit "Biodiversity and Ecosystem Functioning (BEF)-China" in subtropical China. The "New Integrated Litter Experiment (NILEx)" used as platform combining different subprojects of BEF-China dealing with "decomposition and nutrient cycling", "mechanisms of soil erosion" and "functional effects of herbivores, predators and saproxylics" in one experiment. In NILEx, 96 40cm x 40cm runoff plots on two hill slopes inside a castanea molissima forest plantation have been installed and filled with seven different types of litter cover. 16 one-species plots, 24 two-species plots, 4 four-species plots and 4 bare ground plots have been set up, each replicated once. We prepared 48 Plots with traps (Renner solution) for soil macrofauna (diplopods and collembola), so half of the plots were kept free from fauna while the other half was accessible for fauna. Rainfall was generated artificially by using a rainfall simulator with a continuous and stable intensity of 60 mm/h. Our experiments included two runs of 20 minutes duration each, both conducted at two different time steps (summer 2012 and autumn 2012). Runoff volume and sediment discharge were measured every 5 minutes during one rainfall run. Litter coverage and litter mass were recorded at the beginning (summer 2012) and at the end of the experiment (autumn 2012). Our results show that sediment discharge as well as runoff volume decreases

  10. Effects of wildfire and prescribed burning on soil fauna in boreal coniferous forests

    OpenAIRE

    Malmström, Anna

    2006-01-01

    Fire is considered as the most important disturbance agent in many ecosystems. In northern Europe, fire suppression is today highly effective. This has led to a reduction of species that are dependent on fire for their long-term survival. Above ground positive responses of animal diversity to fire are common, whereas the knowledge of the responses of soil fauna to fire is fairly poor. The main aim of this thesis was to determine effects of wildfire and prescribed burning on survival and recov...

  11. [Community traits of soil fauna in forestlands converted from cultivated lands in limestone red soil region of Ruichang, Jiangxi Province of China].

    Science.gov (United States)

    Li, Tao; Liu, Yuan-Qiug; Guo, Sheng-Mao; Ke, Guo-Qing; Zhang, Zhao; Xiao, Xu-Bao; Liu, Wu

    2012-04-01

    This paper studied the variations of the community composition and individuals' number of soil fauna in limestone red soil region of Ruichang, Jiangxi Province after six years of converting cultivated lands into forestlands. Three converted forestlands, including the lands of mixed multiple-species forest, bamboo-broadleaved forest, and tree-seedling integration, were selected as test objects, with cultivated lands as the comparison. A total of 34 orders, 17 classes, and 6 phyla of soil fauna were observed in the converted forestlands. The dominant group was Nematoda, accounting for 86.7% of the total, whereas Acarina, Enchytraeidae, and Collembola were the common groups. In the cultivated lands, soil fauna had 21 orders, 10 classes, and 5 phyla. The dominant group was also Nematoda, accounting 86.7% of the total, and Acarina and Enchytraeidae were the common groups. In the converted forestlands, the group number of rare species was greater than that in the cultivated lands (30 vs. 18), and, except in winter, the group number and average density were significantly higher than those in the cultivated lands (P soil fauna in the soil profiles showed an obvious surface accumulation, which was more apparent in converted forestlands than in cultivated lands, and the individuals' number had significant differences between the surface (0-5 cm) layer and the 5-10 cm and 10-15 cm layers (P soil fauna in the converted forestlands had a seasonal variation ranked in the order of summer > autumn > spring > winter, and there was a significant difference between summer-autumn and spring-winter. The average density of the soil fauna also had a seasonal variation but ranked as autumn > summer > spring > winter, and the differences among the seasons were significant (P soil fauna was significantly higher in converted forestlands than in cultivated lands, and was the highest in mixed multiple-species forestland and the least in tree-seedling integration land. PMID:22803453

  12. Insect fauna in soil at different grassland ecosystems at Sobral, state of Ceará, Brazil

    Directory of Open Access Journals (Sweden)

    Gislane dos Santos Sousa

    2013-02-01

    Full Text Available The aim of this study was perform a surveillance of the insect fauna in soil in three grassland ecosystems of experimental farm Vale do Acaraú of Universidade Estadual Vale do Acaraú at Sobral, state of Ceará, Brazil, by the using of traps soil, with fortnightly collections, from March 2011 to February 2012. To characterize the insect fauna established a distribution pattern, whereas the rates of occurrence and dominance of species grouped by order, as an indicator of the frequency and the occurrence of the amount of captured. At the end, we collected and identified a total of 17,008 specimens of insects belonging to 11 orders, namely: Blattariae, Coleoptera, Dermaptera, Diptera, Hemiptera, Hymenoptera, Isoptera, Lepidoptera, Odonata, Orthoptera and Mantodea. The Order Hymenoptera was the one that stood out the largest number of individuals captured, attributing the presence of large amount of ants, are still considered common to the three ecosystems studied, according to the method employed.

  13. Seasonal exposure to drought and air warming affects soil Collembola and mites.

    Directory of Open Access Journals (Sweden)

    Guo-Liang Xu

    Full Text Available Global environmental changes affect not only the aboveground but also the belowground components of ecosystems. The effects of seasonal drought and air warming on the genus level richness of Collembola, and on the abundance and biomass of the community of Collembola and mites were studied in an acidic and a calcareous forest soil in a model oak-ecosystem experiment (the Querco experiment at the Swiss Federal Research Institute WSL in Birmensdorf. The experiment included four climate treatments: control, drought with a 60% reduction in rainfall, air warming with a seasonal temperature increase of 1.4 °C, and air warming + drought. Soil water content was greatly reduced by drought. Soil surface temperature was slightly increased by both the air warming and the drought treatment. Soil mesofauna samples were taken at the end of the first experimental year. Drought was found to increase the abundance of the microarthropod fauna, but reduce the biomass of the community. The percentage of small mites (body length ≤ 0.20 mm increased, but the percentage of large mites (body length >0.40 mm decreased under drought. Air warming had only minor effects on the fauna. All climate treatments significantly reduced the richness of Collembola and the biomass of Collembola and mites in acidic soil, but not in calcareous soil. Drought appeared to have a negative impact on soil microarthropod fauna, but the effects of climate change on soil fauna may vary with the soil type.

  14. Efeito de restos da cultura do abacaxizeiro e de agrobio na fauna do solo Effect of residues of pineaplle plant and agrobio in the soil fauna

    Directory of Open Access Journals (Sweden)

    Alecsandra de Almeida

    2010-12-01

    Full Text Available Objetivou-se avaliar o efeito de restos culturais de abacaxizeiro (Ananas comosus L. 'Smooth Cayenne' na fauna de artrópodes,em cultivos em campo. As mudas, do tipo filhote, foram plantadas no mês de junho, em um Latossolo Vermelho Amarelo, que recebeu 0, 30 e 60t/ha de restos de abacaxizeiro, aplicados superficialmente e incorporados a 10cm de profundidade, com e sem a adição do biofertilizante-Agrobio10% (v/v. Foram coletadas amostras a 05 cm de profundidade aos 90, 210, 330 e 450 dias após a aplicação dos resíduos. Identificou-se, durante os 15 meses de avaliações, o predomínio de Acari e Collembola. A maior densidade de animais foi observada na primeira amostragem, aos 90 dias após a adição dos restos. No entanto, diferenças na abundância da fauna de solo só foram observadas, 330 dias após a adição dos resíduos.This study was conducted under field conditions, in order to determine the effect of pineapple crop (Ananas comosus L. residues on the edaphic arthropod fauna. Slips were planted in June, in Red-Yellow Latossol , with crop residues in amounts of 0, 30 and 60 t/ha, placed on the surface or tilled under 10cm, with and without 10% (v/v Agrobio biofertilizer applied along with the residues and sprayed monthly at 3% (v/v two months after planting. Soil samples were collected from the top 5.0 cm of soil at 90, 210, 330 and 450 days after the application of residues. Over 15 months, the predominance of Acari and Collembolan was observed. The highest density of animals was observed in the first sample, at 90 days after the addition of residues. Nevertheless, differences in soil fauna abundance between treatments were not detected until 330 days after soil management with crop residues.

  15. Evaluation of meso fauna soil as bio-indicator of environmental quality in forests remnants in the city of São Paulo - Preliminary Results

    Science.gov (United States)

    Patucci, Natalia; Oliveira, Deborah

    2014-05-01

    Soil quality is particularly through composition and structure, as well as by, measured by physical and chemical indicators, as well as by living organisms contained therein, which play the most varied ecological functions. The abundance and diversity of soil macrofauna in ecosystems can be affected by many factors, precisely because these organisms are sensitive to environmental changes, whether induced or natural. Thus, soil populations can be measured as bioindicators, since changes in the community may indicate possible changes in soil functioning. This research aims to survey the biodiversity of meso soil fauna environments with remaining Atlantic Forest (Fontes do Ipiranga park, Cantareira park and Jaraguá park) in order to detect specific features and significant changes in ecological function performed by these soil communities. The project aims to develop an overview of multivariate understanding about soil, especially the relation of variation of pedofauna with the occurring physical and chemical modifications in order to be able to prove the adaptation of soil fauna with variations in temperature, humidity, sunshine, influence of vegetation, soil genesis and topographic gradient. According to Lavelle & Spain (2001), the temperature and humidity are the main factors that activate the metabolic regulation in subjects of soil fauna, which ultimately determine their spatial distribution, periods of increased activity, peculiarities and significant changes, the function of these communities in the substrate. Two combining sampling will be performed, one in the rainy season, in January, and another in the dry season, in July, with the purpose of measuring the diversity of populations according to seasonality. Invertebrates associated soil interface - burlap (Moreira et al, 2010) will be caught by pitfall traps, which will be distributed in three installments by park, containing a sampling gride with nine equidistant points 30 meters of each other. Through

  16. Disturbance-diversity relationships for soil fauna are explained by faunal community biomass in a salt marsh

    NARCIS (Netherlands)

    Thakur, Madhav Prakash; Berg, Matty P.; Eisenhauer, Nico; van Langevelde, Frank

    2014-01-01

    Disturbance-diversity relationships have long been studied in ecology with a unimodal relationship as the key prediction. Although this relationship has been widely contested, it is rarely tested for soil invertebrate fauna, an important component of terrestrial biodiversity. We tested disturbance-d

  17. Soil fauna across Central European sandstone ravines with temperature inversion: From cool and shady to dry and hot places

    Czech Academy of Sciences Publication Activity Database

    Schlaghamerský, J.; Devetter, Miloslav; Háněl, Ladislav; Tajovský, Karel; Starý, Josef; Tuf, I.H.; Pižl, Václav

    2014-01-01

    Roč. 83, November (2014), s. 30-38. ISSN 0929-1393 Grant ostatní: EEA Financial Mechanism(NO) CZ0048 Institutional research plan: CEZ:AV0Z60660521 Institutional support: RVO:60077344 Keywords : soil fauna * ravines * gorges * environmental gradients * species richnes * drought Subject RIV: EH - Ecology, Behaviour Impact factor: 2.644, year: 2014

  18. Soil pH and earthworms affect herbage nitrogen recovery from solid cattle manure in production grassland

    NARCIS (Netherlands)

    Rashid, M.I.; Goede, de R.G.M.; Corral Nunez, G.A.; Brussaard, L.; Lantinga, E.A.

    2014-01-01

    Long term use of inorganic fertilisers and reduced organic matter inputs have contributed to acidification of agricultural soils. This strongly affects the soil dwelling fauna and nutrient mineralisation. Organic fertilisers such as solid cattle manure (SCM) resurge as an option to overcome this aci

  19. Interactions between soil development, vegetation and soil fauna during spontaneous succession in post mining sites

    Czech Academy of Sciences Publication Activity Database

    Frouz, Jan; Prach, Karel; Pižl, Václav; Háněl, Ladislav; Starý, Josef; Tajovský, Karel; Materna, J.; Balík, Vladimír; Kalčík, Jiří; Řehounková, K.

    2008-01-01

    Roč. 44, č. 1 (2008), s. 109-121. ISSN 1164-5563 R&D Projects: GA ČR GA526/01/1055; GA ČR(CZ) GA526/06/0728; GA AV ČR 1QS600660505 Institutional research plan: CEZ:AV0Z60660521; CEZ:AV0Z60050516 Keywords : succession * soil microstructure * soil formation Subject RIV: EH - Ecology, Behaviour Impact factor: 0.888, year: 2008

  20. Investigation of Wetland Soil Properties affecting Optimum Soil Cultivation

    OpenAIRE

    Babatunde, O. O.; K.A. Adeniran

    2010-01-01

    An investigation was carried out on wetland (fadama) soil properties affecting optimum soil cultivation. A cone penetrometerand a shear vane apparatus (19 mm) were used to determine the cone index and the torque that cause the soil to shearat different moisture contents. The study shows that the cone index and shear vane of fadama soils increased with depth anddecreased with increase in moisture content. High moisture content reduced the soil cohesion. The internal frictional angleof the soil...

  1. Development of metabarcoding for tracking changes of soil fauna community under stress by application of ash

    DEFF Research Database (Denmark)

    Qin, J; de Groot, G.A.; Hansen, L. H.;

    Ash is a waste product from combustion of bio-fuel in power plants. Application of ash on soil ensures nutrient recycling, but detrimental ecotoxicological consequences may arise since ash is a complex mixture that may contain compounds affecting soil invertebrates and their food and habitat...... species. DNA metabarcoding, which couples the principle of DNA barcoding with next generation sequencing technology, has the potential to simplify community diversity monitoring. However, sampling and DNA extraction methods for the purpose of soil microarthropod metabarcoding have not been yet fully...

  2. Effects of the increased radium content in soil on the soil fauna

    International Nuclear Information System (INIS)

    The effect of elevated radioactive background due to the presence of natural radionuclide of radium-226 on soil animals has been studied. The areas being studied (1-2 hectares) had the elevated radioactivity ranging from 50 to 4000 μR/hour and were located on an over-flood-lands terrace with meadow vegetation in the mid-taiga subzone. Histological examination of tegmental epithelium and middle intestine (tissues in direct contact with radium-contaminated soil) was performed on Dendrobaena octaedra (Sav.) and Dendrodrillus rubidus (Sav.) collected from areas with 4000μR/hour radioactivity. A comparison of the results with data obtained earlier for surface animals inhabiting the same areas has corroborated that settled animals inhabiting contaminated areas for a long time suffer from retardation of development and disturbances in the functioning of body epithelium and of the intestine. The effect of radiation on soil animals can be observed in areas with far lower radioactivity (100-200μR/hour), probably due to their closer contact with radium-contaminated soil. The most convenient object for monitoring of the effects of elevated background radioactivity is the earthworm, which is irradiated not only from outside but also from the smallowed soil

  3. Loss of soil (macro)fauna due to the expansion of Brazilian sugarcane acreage.

    Science.gov (United States)

    Franco, André L C; Bartz, Marie L C; Cherubin, Maurício R; Baretta, Dilmar; Cerri, Carlos E P; Feigl, Brigitte J; Wall, Diana H; Davies, Christian A; Cerri, Carlos C

    2016-09-01

    Land use changes (LUC) from pasture to sugarcane (Saccharum spp.) crop are expected to add 6.4Mha of new sugarcane land by 2021 in the Brazilian Cerrado and Atlantic Forest biomes. We assessed the effects of these LUC on the abundance and community structure of animals that inhabit soils belowground through a field survey using chronosequences of land uses comprising native vegetation, pasture, and sugarcane along a 1000-km-long transect across these two major tropical biomes in Brazil. Macrofauna community composition differed among land uses. While most groups were associated with samples taken in native vegetation, high abundance of termites and earthworms appeared associated with pasture soils. Linear mixed effects analysis showed that LUC affected total abundance (X(2)(1)=6.79, p=0.03) and taxa richness (X(2)(1)=6.08, p=0.04) of soil macrofauna. Abundance increased from 411±70individualsm(-2) in native vegetation to 1111±202individualsm(-2) in pasture, but decreased sharply to 106±24individualsm(-2) in sugarcane soils. Diversity decreased 24% from native vegetation to pasture, and 39% from pasture to sugarcane. Thus, a reduction of ~90% in soil macrofauna abundance, besides a loss of ~40% in the diversity of macrofauna groups, can be expected when sugarcane crops replace pasture in Brazilian tropical soils. In general, higher abundances of major macrofauna groups (ants, coleopterans, earthworms, and termites) were associated with higher acidity and low contents of macronutrients and organic matter in soil. This study draws attention for a significant biodiversity loss belowground due to tropical LUC in sugarcane expansion areas. Given that many groups of soil macrofauna are recognized as key mediators of ecosystem processes such as soil aggregation, nutrients cycling and soil carbon storage, our results warrant further efforts to understand the impacts of altering belowground biodiversity and composition on soil functioning and agriculture performance

  4. Soil macrofauna webmasters of ecosystem

    Science.gov (United States)

    Frouz, Jan

    2015-04-01

    The role of plant roots and microflora in shaping many ecosystem processes is generally appreciated in the contrary rho role of soil mcrofauna in this context is assumed to be negligible and rather anecdotic. But more than half of the litter fall is consumed by soil fauna and soil fauna can also consume and or translocation substantial amount of soil. Here we demonstrate on example of post mining chronosequences how site colonization by soil fauna affect composition of whole soil biota community, plant succession and soil formation. Filed and laboratory experiments show that decomposition of fauna feces may be sped up compare to litter at the very beginning but in long term fauna feces decompose slower than litter. This is also supported by micro morphological observation which shows that fauna feces form substantial part of soil. Fauna feces also induce lover or even negative priming effect when introduced in soil in comparison with litter that triggers positive priming effect. Laboratory experiment show that fauna effect is context sensitive and is more pronounced in systems already affected by soil fauna. Soil mixing by soil fauna consequently affect environmental conditions in soils such as water holding capacity or nutrient availability, it also affect composition of decomposer food web including microbial community (fungal bacterial ratio) which feed back in alternation of plant community composition during succession This fauna activity is not constant everywhere the higher effect of fauna activity on litter layer was observed in temperate soils of deciduous forests and with litter having CN between 20-30. In conclusion soil fauna use directly only small proportion of energy in the litter but can substantially affect soil carbon turnover, soil formation, decomposer food web and plant community.

  5. Biological functioning of PAH-polluted and thermal desorption-treated soils assessed by fauna and microbial bioindicators.

    Science.gov (United States)

    Cébron, Aurélie; Cortet, Jérôme; Criquet, Stéven; Biaz, Asmaa; Calvert, Virgile; Caupert, Cécile; Pernin, Céline; Leyval, Corinne

    2011-11-01

    A large number of soil bioindicators were used to assess biological diversity and activity in soil polluted with polycyclic aromatic hydrocarbons (PAHs) and the same soil after thermal desorption (TD) treatment. Abundance and biodiversity of bacteria, fungi, protozoa, nematodes and microarthropods, as well as functional parameters such as enzymatic activities and soil respiration, were assessed during a two year period of in situ monitoring. We investigated the influence of vegetation (spontaneous vegetation and Medicago sativa) and TD treatment on biological functioning. Multivariate analysis was performed to analyze the whole data set. A principal response curve (PRC) technique was used to evaluate the different treatments (various vegetation and contaminated vs. TD soil) contrasted with control (bare) soil over time. Our results indicated the value of using a number of complementary bioindicators, describing both diversity and functions, to assess the influence of vegetation on soil and discriminate polluted from thermal desorption (TD)-treated soil. Plants had an influence on the abundance and activity of all organisms examined in our study, favoring the whole trophic chain development. However, although TD-treated soil had a high abundance and diversity of microorganisms and fauna, enzymatic activities were weak because of the strong physical and chemical modifications of this soil. PMID:21392572

  6. Variation of Soil Fauna Community in Eucalyptus grandis Plantation Before and After Felling Disturbance%采伐干扰前后巨桉人工林土壤动物群落比较

    Institute of Scientific and Technical Information of China (English)

    肖玖金; 张健; 黄玉梅; 马红星; 李旭东

    2011-01-01

    In order to understand the response of soil animal community to harvesting disturbance and evaluate the ecological etfect of a eucalypt plantation, an investigation on soil fauna was carried out in the eucalypt (Eucalyptus grandis) plantation which was planted in 1997 and harvested in August 2006. Soil macro-fauna were picked up by hand. Nematodes and mesofauna were separated and collected from the soil samples by Baermann and Tullgren methods, respectively. Totally, 5 578 individuals of soil fauna, belonging to 4 phyla, 10 classes and 25 orders were collected before and after felling disturbance, and the individuals of soil fauna were 1 290 fewer than those before felling. Individuals were easier affected by felling disturbance than group numbers. Acarina, Hymenoptera and Nematode occupied 91.76% of the total decreased individuals, Collembolan 88.99%of the total increased individuals, and other soil fauna changed insignificantly. The meso-micro soil fauna (including those collected by Baermann and Tullgren methods) were mainly distributed in top soil layer, which was negatively correlated with soil temperature, and positively with soil organic content and soil moisture. The felling disturbance represented a significant effect on meso-micro soil fauna (P < 0.01). Shannon-Wiener (H') and Pielou (J) indexes increased significantly ( P > 0.05), DG index decreased extremely significantly ( P < 0.01), Simpson(C) index of plot A decreased and plot B increased, indicating that havesting disturbance had induced significant eftects on the structure of soil fauna in the eucalypt plantation. Tab 6, Ref 33%为了解采伐干扰对巨桉人工林土壤动物的影响,采用手捡法和干湿漏斗法对四川省洪雅县巨桉人工林采伐干扰前和干扰后土壤动物群落进行调查.结果显示:巨桉人工林采伐干扰前后共获大中小型土壤动物5 578头,分属4门10纲25目,采伐干扰后共减少1 290头,类群数减少了3个.采伐干扰前

  7. Effects of tillage mode on the diversity of soil meso- and micro-fauna%耕作方式对中小型土壤动物多样性影响

    Institute of Scientific and Technical Information of China (English)

    战丽莉; 许艳丽; 张兴义; 潘凤娟; 裴希超; 刘振宇

    2012-01-01

    moldboard plough and rotary tillage and between no tillage and reduced tillage. Combined tillage kept the surface accumulation of soil fauna. The diversity, evenness, and dominance of the soil fauna under reduced tillage were higher than those under other tillage modes. It was suggested that tillage mode could affect the community structure of soil meso- and micro-fauna, and conservation tillage (combined tillage and reduced tillage) could benefit the stability of soil faunal community structure and kept the surface accumulation of soil fauna in vertical distribution.

  8. Análise multivariada da fauna edáfica em diferentes sistemas de preparo e cultivo do solo Multivariate analysis of soil fauna under different soil tillage and crop management systems

    Directory of Open Access Journals (Sweden)

    Dilmar Baretta

    2006-11-01

    Full Text Available O objetivo deste trabalho foi avaliar o efeito de sistemas de preparo e cultivo do solo sobre a diversidade de animais da fauna edáfica, por meio de técnicas de análise multivariada. Na análise canônica discriminante, os preparos conservacionistas com sucessão de culturas foram separados em relação aos tratamentos com rotação de culturas. Os grupos Acarina, Hymenoptera, Isopoda e Collembola, e o índice de Shannon (H foram os atributos que mais contribuíram para separar os tratamentos. A análise de correspondência mostrou forte associação dos grupos Acarina e Hymenoptera com o tratamento semeadura direta com sucessão de culturas, e do grupo Collembola com o preparo convencional.The objective of this work was to evaluate the effect of different soil tillage and crop management systems on soil fauna groups, by means of multivariate analysis. In the canonical discriminant analysis the conservation soil management systems with crop succession were discriminated in relation to other treatments with crop rotation. The groups Acarina, Hymenoptera, Isopoda, and Collembola, and the Shannon index (H showed the highest contribution for the discrimination between treatments. The correspondence analysis showed a strong association between Acarina and Hymenoptera groups with the treatment no-tillage with crop succession, and between Collembola group with the conventional tillage system.

  9. Evaluating the Applicability of Phi Coefficient in Indicating Habitat Preferences of Forest Soil Fauna Based on a Single Field Study in Subtropical China.

    Directory of Open Access Journals (Sweden)

    Yang Cui

    Full Text Available Phi coefficient directly depends on the frequencies of occurrence of organisms and has been widely used in vegetation ecology to analyse the associations of organisms with site groups, providing a characterization of ecological preference, but its application in soil ecology remains rare. Based on a single field experiment, this study assessed the applicability of phi coefficient in indicating the habitat preferences of soil fauna, through comparing phi coefficient-induced results with those of ordination methods in charactering soil fauna-habitat(factors relationships. Eight different habitats of soil fauna were implemented by reciprocal transfer of defaunated soil cores between two types of subtropical forests. Canonical correlation analysis (CCorA showed that ecological patterns of fauna-habitat relationships and inter-fauna taxa relationships expressed, respectively, by phi coefficients and predicted abundances calculated from partial redundancy analysis (RDA, were extremely similar, and a highly significant relationship between the two datasets was observed (Pillai's trace statistic = 1.998, P = 0.007. In addition, highly positive correlations between phi coefficients and predicted abundances for Acari, Collembola, Nematode and Hemiptera were observed using linear regression analysis. Quantitative relationships between habitat preferences and soil chemical variables were also obtained by linear regression, which were analogous to the results displayed in a partial RDA biplot. Our results suggest that phi coefficient could be applicable on a local scale in evaluating habitat preferences of soil fauna at coarse taxonomic levels, and that the phi coefficient-induced information, such as ecological preferences and the associated quantitative relationships with habitat factors, will be largely complementary to the results of ordination methods. The application of phi coefficient in soil ecology may extend our knowledge about habitat preferences

  10. Evaluating the Applicability of Phi Coefficient in Indicating Habitat Preferences of Forest Soil Fauna Based on a Single Field Study in Subtropical China.

    Science.gov (United States)

    Cui, Yang; Wang, Silong; Yan, Shaokui

    2016-01-01

    Phi coefficient directly depends on the frequencies of occurrence of organisms and has been widely used in vegetation ecology to analyse the associations of organisms with site groups, providing a characterization of ecological preference, but its application in soil ecology remains rare. Based on a single field experiment, this study assessed the applicability of phi coefficient in indicating the habitat preferences of soil fauna, through comparing phi coefficient-induced results with those of ordination methods in charactering soil fauna-habitat(factors) relationships. Eight different habitats of soil fauna were implemented by reciprocal transfer of defaunated soil cores between two types of subtropical forests. Canonical correlation analysis (CCorA) showed that ecological patterns of fauna-habitat relationships and inter-fauna taxa relationships expressed, respectively, by phi coefficients and predicted abundances calculated from partial redundancy analysis (RDA), were extremely similar, and a highly significant relationship between the two datasets was observed (Pillai's trace statistic = 1.998, P = 0.007). In addition, highly positive correlations between phi coefficients and predicted abundances for Acari, Collembola, Nematode and Hemiptera were observed using linear regression analysis. Quantitative relationships between habitat preferences and soil chemical variables were also obtained by linear regression, which were analogous to the results displayed in a partial RDA biplot. Our results suggest that phi coefficient could be applicable on a local scale in evaluating habitat preferences of soil fauna at coarse taxonomic levels, and that the phi coefficient-induced information, such as ecological preferences and the associated quantitative relationships with habitat factors, will be largely complementary to the results of ordination methods. The application of phi coefficient in soil ecology may extend our knowledge about habitat preferences and distribution

  11. Fire affects root decomposition, soil food web structure, and carbon flow in tallgrass prairie

    OpenAIRE

    Shaw, E. Ashley; Denef, Karolien; Milano de Tomasel, Cecilia; Cotrufo, M. Francesca; Wall, Diana H

    2016-01-01

    Root litter decomposition is a major component of carbon (C) cycling in grasslands, where it provides energy and nutrients for soil microbes and fauna. This is especially important in grasslands where fire is common and removes aboveground litter accumulation. In this study, we investigated whether fire affects root decomposition and C flow through the belowground food web. In a greenhouse experiment, we applied 13C-enriched big bluestem (Andropogon gerardii) root litter to ...

  12. Effects of Mangrove Zonation and the Physicochemical Parameters of Soil on the Distribution of Macrobenthic Fauna in Kadolkele Mangrove Forest, a Tropical Mangrove Forest in Sri Lanka

    OpenAIRE

    Navodha Dissanayake; Upali Chandrasekara

    2014-01-01

    The ecology of the macrobenthic fauna of the mangrove forests has received little attention compared to the mangrove flora. The present study was aimed at filling this information gap and investigated if the diversity and distribution of macrobenthic fauna at Kadolkele mangrove forest, a pristine mangrove forest situated at the Negombo estuary in Sri Lanka, are governed by the mangrove zonation and variation of physicochemical parameters of the mangrove soil. Since the aerial photographs iden...

  13. Brachiaria species affecting soil nitrification

    OpenAIRE

    Adalton Mazetti Fernandes; Gabriel José Massoni de Andrade; Emerson de Freitas Cordova de Souza; Ciro Antonio Rosolem

    2011-01-01

    Nitrification can lead to substantial losses of the applied N through nitrate leaching and N2O emission. The regulation of nitrification may be a strategy to improve fertilizer N recovery and increase its agronomic efficiency. The objective of this study was to evaluate the inhibiting capacity of nitrification in soil by Brachiaria species. The greenhouse experiment was conducted using pots with 10 dm³ of a Red Latosol sample. The treatments consisted of the cultivation of three forage specie...

  14. Effects of ivermectin application on the diversity and function of dung and soil fauna: Regulatory and scientific background information

    DEFF Research Database (Denmark)

    Adler, Nicole; Blanckenhorn, Wolf U; Bachmann, Jean;

    2016-01-01

    on communities of dung-breeding insects and soil fauna under field conditions, the test method meets the requirements of a higher-tier test as mandated by the European Union. The present study provides contextual information on authorization requirements for veterinary medicinal products and on the structure...... and function of dung and soil organism communities. It also provides a summary of the main findings. Subsequent studies on this issue provide detailed information on different aspects of this overall project....... for veterinary medicinal products in the European Union includes a requirement for higher-tier tests when adverse effects on dung organisms are observed in single-species toxicity tests. However, no guidance documents for the performance of higher-tier tests are available. Hence, an international research...

  15. Soil physical properties affecting soil erosion in tropical soils

    International Nuclear Information System (INIS)

    The total vegetated land area of the earth is about 11,500 hectare. Of this, about 12% is in South America. Of this, about 14% is degraded area. Water erosion, chemical degradation, wind erosion, and physical degradation have been reported as main types of degradation. In South America water erosion is a major process for soil degradation. Nevertheless, water erosion can be a consequence of degradation of the soil structure, especially the functional attributes of soil pores to transmit and retain water, and to facilitate root growth. Climate, soil and topographic characteristics determine runoff and erosion potential from agricultural lands. The main factors causing soil erosion can be divided into three groups: Energy factors: rainfall erosivity, runoff volume, wind strength, relief, slope angle, slope length; Protection factors: population density, plant cover, amenity value (pressure for use) and land management; and resistance factors: soil erodibility, infiltration capacity and soil management. The degree of soil erosion in a particular climatic zone, with particular soils, land use and socioeconomic conditions, will always result from a combination of the above mentioned factors. It is not easy to isolate a single factor. However, the soil physical properties that determine the soil erosion process, because the deterioration of soil physical properties is manifested through interrelated problems of surface sealing, crusting, soil compaction, poor drainage, impeded root growth, excessive runoff and accelerated erosion. When an unprotected soil surface is exposed to the direct impact of raindrops it can produce different responses: Production of smaller aggregates, dispersed particles, particles in suspension and translocation and deposition of particles. When this has occurred, the material is reorganized at the location into a surface seal. Aggregate breakdown under rainfall depends on soil strength and a certain threshold kinetic energy is needed to start

  16. Investigation of Wetland Soil Properties affecting Optimum Soil Cultivation

    Directory of Open Access Journals (Sweden)

    O.O. Babatunde

    2010-01-01

    Full Text Available An investigation was carried out on wetland (fadama soil properties affecting optimum soil cultivation. A cone penetrometerand a shear vane apparatus (19 mm were used to determine the cone index and the torque that cause the soil to shearat different moisture contents. The study shows that the cone index and shear vane of fadama soils increased with depth anddecreased with increase in moisture content. High moisture content reduced the soil cohesion. The internal frictional angleof the soil was 37.90. The following values were obtained for soil cohesion 112 kN/m2, 62 kN/m2, 38 kN/m2, 30 kN/m2, and12 kN/m2 at moisture contents of 0%, 5%, 10%, 15% and 20% respectively. Moisture content between 10% -15% (dry basisappeared ideal for cultivation of the soil. For this soil the critical moisture content was found to be 23.72%. Moisture contentbeyond the critical level needs to be drained before cultivation is carried out.

  17. Fauna del suelo en bosques y cafetales de la Sierra Nevada de Santa Marta, Colombia Soil fauna in forest and coffee plantations from the Sierra Nevada de Santa Marta, Colombia

    Directory of Open Access Journals (Sweden)

    Camero R. Edgar

    2002-11-01

    Full Text Available

    En la Sierra Nevada de Santa Marta se establecieron dos estaciones de muestreo en las localidades de Minca a 700 m de altitud y María Teresa a 790 m, para realizar comparaciones de la fauna asociada a los suelos de plantaciones de café y de bosques naturales. Las colecciones se realizaron tanto en la hojarasca como en los horizontes  subsuperficiales O, Ay B de las dos coberturas vegetales mediante el empleo de trampas Pitfall y Berlesse y se utilizaron índices de diversidad, abundancia relativa y frecuencia para comparar su composici6n biológica, la cual se determine a nivel de familia. Los resultados mostraron diferencias significativas, tanto en la composición como en la abundancia y frecuencia de los grupos colectados en los dos tipos de ecosistemas, así Como variaciones altitudinales significativas al comparar los resultados obtenidos en los bosques nativos con trabajos hechos en zonas de mayor altitud en este sistema montañoso.

    Two research stations (Minca, 700 m altitude and Marfa Teresa, 790 m altitude were established in the Sierra Nevada de Santa Marta in places to study the soil fauna associated with forest and coffee plantations. Soil fauna was collected using Pitfall and Berlesse traps. Samples were taken from litter as well as from horizons O, A and B. Individuals collected were identified to family level. Diversity, abundance and frequency indexes were used to compare fauna composition at both sites. Significant differences were found between the two research sites as well as with data from other high altitude forest in the Sierra Nevada de Santa Marta.

  18. Evaluating the Applicability of Phi Coefficient in Indicating Habitat Preferences of Forest Soil Fauna Based on a Single Field Study in Subtropical China

    OpenAIRE

    Cui, Yang; Wang, Silong; Yan, Shaokui

    2016-01-01

    Phi coefficient directly depends on the frequencies of occurrence of organisms and has been widely used in vegetation ecology to analyse the associations of organisms with site groups, providing a characterization of ecological preference, but its application in soil ecology remains rare. Based on a single field experiment, this study assessed the applicability of phi coefficient in indicating the habitat preferences of soil fauna, through comparing phi coefficient-induced results with those ...

  19. Fauna of soil nematodes (Nematoda) in coal post-mining sites in Illinois, USA

    Czech Academy of Sciences Publication Activity Database

    Háněl, Ladislav

    České Budějovice : Institute of Soil Biology, BC ASCR, 2011. s. 25. ISBN 978-80-86525-19-8. [Central European Workshop on Soil Zoology /11./. 11.04.2011-14.04.2011, České Budějovice] R&D Projects: GA MŠk ME08019 Institutional research plan: CEZ:AV0Z60660521 Keywords : soil nematodes * coal post mining sites * Illinois Subject RIV: EH - Ecology, Behaviour

  20. Earthworms and priming of soil organic matter - The impact of food sources, food preferences and fauna - microbiota interactions

    Science.gov (United States)

    Potthoff, Martin; Wichern, Florian; Dyckmans, Jens; Joergensen, Rainer Georg

    2016-04-01

    Earthworms deeply interact with the processes of soil organic matter turnover in soil. Stabilization of carbon by soil aggregation and in the humus fraction of SOM are well known processes related to earthworm activity and burrowing. However, recent research on priming effects showed inconsistent effects for the impact of earthworm activity. Endogeic earthworms can induce apparent as well as true positive priming effects. The main finding is almost always that earthworm increase the CO2 production from soil. The sources of this carbon release can vary and seem to depend on a complex interaction of quantity and quality of available carbon sources including added substrates like straw or other compounds, food preferences and feeding behavior of earthworms, and soil properties. Referring to recent studies on earthworm effects on soil carbon storage and release (mainly Eck et al. 2015 Priming effects of Aporrectodea caliginosa on young rhizodeposits and old soil organic matter following wheat straw addition, European Journal of Soil Biology 70:38-45; Zareitalabad et al. 2010 Decomposition of 15N-labelled maize leaves in soil affected by endogeic geophagous Aporrectodea caliginosa, Soil Biology and Biochemistry 42(2):276-282; and Potthoff et al. 2001 Short-term effects of earthworm activity and straw amendment on the microbial C and N turnover in a remoistened arable soil after summer drought, Soil Biology and Biochemistry 33(4):583-591) we summaries the knowledge on earthworms and priming and come up with a conceptual approach and further research needs.

  1. Do soil fauna really hasten litter decomposition? A meta-analysis of enclosure studies

    Czech Academy of Sciences Publication Activity Database

    Frouz, J.; Roubíčková, A.; Heděnec, P.; Tajovský, Karel

    2015-01-01

    Roč. 68, May-June (2015), s. 18-24. ISSN 1164-5563 Grant ostatní: GA ČR(CZ) GAP504/12/1288 Institutional support: RVO:60077344 Keywords : Invertebrates * bioturbation * soil organic matter * carbon cycle * litter bag Subject RIV: DF - Soil Science Impact factor: 1.719, year: 2014

  2. Epigeal fauna of a degraded soil treated with mineral fertilizer and compound cellulose cultivated of tree species

    Science.gov (United States)

    Giácomo, R. G.; de Arruda, O. G.; Souto Filho, S. N.; Alves, M. C.; Pereira, M. G.; Frigério, G. C.

    2012-04-01

    The aim of this study was to investigate the behavior of the epigeal fauna in a degraded soil in the recovery process after one year of cultivated with tree species. The experiment was established in February 2010 in Mato Grosso do Sul, Brazil. The experimental design was randomized blocks in split plots with five treatments and four replications. In the main plots, pure cultivation of Eucalyptus urograndis (exotic species - hybrids) and Mabea fistulifera Mart. (native species) and the subplot treatments: Control; D0 - without fertilization; DM - mineral fertilizer according to crop need; DC - with compost manure according to crop need (10 t ha-1); D15 - 15 t ha-1 and D20 - 20 t ha-1 of the compound. In February of the years 2010 and 2011 were installed in the central region of each treatment two traps "pitt fall" which remained for seven days in the field. We calculated Shannon diversity and Pielou evenness indices, and richness of wildlife activity groups. The results were analyzed by ANOVA and Scott Knott test at 5% significance level. In 2010, the area with M. fistulifera, was captured a total of 2697 organisms distributed mainly in: Hymenoptera with 45.83% of the total collected, Collembola (36.93%), Hemiptera Heteroptera (6.56%). In the area with E. urograndis, 1938 organisms were captured, being 50.67% of the order Hymenoptera, Collembola 26.83%, 7.59% Hemiptera Heteroptera. It was found that there was no significant difference between treatments and between species for all variables. Collected in 2011 were 4970 organisms in 56.22% of the order Hymenoptera, Collembola 18.49% and 7.12% beetle in the area of M. fistulifera. In the area of E. urograndis were 4200 organisms, 55.29% (Hymenoptera), 23.79% (Collembola) and 5.86% (Coleoptera). It appears that the activity values and richness of the fauna groups were significantly higher in treatments with organic fertilization in both cultive. It is concluded that after one year there was a variation of the dominant

  3. Effects of a complete removal of harvest residues on the soil fauna; Effekter av GROT-uttag paa biologisk maangfald hos markfaunan

    Energy Technology Data Exchange (ETDEWEB)

    Persson, Tryggve; Ahlstroem, Kerstin; Lindberg, Niklas [Swedish Univ. of Agricultural Sciences, Uppsala (Sweden). Dept. of Ecology and Environmental Research

    2005-02-01

    The aim was to assess the effects of a complete removal of harvest residues (slash) from forest clear-cuts in relation to a situation with 1,2 and 4 times normal amount of harvest residues on the diversity of soil fauna. The study was made at two sites, Asa in Smaaland and Turbo in Dalarna. The comparison also included uncut, mature forests surrounding the clear-cuts. Ideally, the study should have continued for several years, but because of limited economy, the study focused on the period 1.5 year after the clear-cut. The soil fauna groups reported here are Enchytraeidae, Tardigrada, Diptera and Oribatida. The results show that clear-cutting leads to a marked decline in the density and species number of oribatid mites and an increase in the density (but not species) of Enchytraeidae. Slash removal could not be shown to affect the species number of oribatids. Certain species clearly decreased in number after slash removal, but the species were normally present, although in low numbers, 1.5 year after the clear-cut. Some Diptera species (larvae) were solely observed below the heaps of slash, but the results are too circumstantial for a certain conclusion. The short period between the treatment start and the sampling limits the generality of the findings. The generation times of most oribatid mites are one year or more. There are studies indicating that some species have generation times up to 2-3 years. If the sensitive life stages are the juveniles, presence of long-lived adults may hide detrimental effects. This means that the study has covered too short a time to conclude whether removal of slash will affect oribatid diversity. Consequently, we cannot exclude the possibility that removal of harvest residues can result in a threat to the diversity of oribatid mites. To be able to answer the question in a satisfactorily manner, a follow-up study is needed during forthcoming years. In conclusion, removal of slash had small effects on enchytraeid species and reduced

  4. Distribution of Pill Millipedes (Arthrosphaera) and Associated Soil Fauna in the Western Ghats and West Coast of India

    Institute of Scientific and Technical Information of China (English)

    K. M. ASHWINI; K. R. SRIDHAR

    2008-01-01

    Seven sampling sites in each of three biomes (Western Ghats, foothills of Western Ghats and west coast) of south-western India were investigated to study the distribution, abundance and ecology of pill millipedes (Arthrosphaera) and associated fauna in relation to edaphic features. Abundance and biomass of Arthrosphaera and other millipedes were the highest in Western Ghats, while earthworms were in foothills. Arthrosphaera magna and Arthrosphaera spp. were common in Western Ghats and foothills respectively, while no Arthrosphaera were found in the west coast. None of the sampling sites consisted of more than one species of Arthrosphaera. Biomass of Arthrosphaera, other millipedes and earthworms significantly differed in Western Ghats (P = 9.48 × 10-7) and foothills (P = 1.35 × 10-8), as did the biomass of species of Arthrosphaera (P = 2.76 × 10-7) between Western Ghats and foothills. Correlation analysis revealed that biomass of Arthrosphaera was significantly (P = 0.01, r = 0.45) correlated with soil organic carbon rather than other edaphic fea-tures (pH, phosphate, calcium and magnesium). Distribution pattern, abundance, biomass and ecology of Arthrosphaera of Western Ghats in relation to soil qualities were compared with millipedes of other regions of the world.

  5. Caracterização da fauna edáfica em diferentes coberturas vegetais na região norte Fluminense Characterization of soil fauna in different vegetation covers in the northern Fluminense region (RJ

    Directory of Open Access Journals (Sweden)

    Maria Kellen da S. Moço

    2005-07-01

    Full Text Available O sistema solo-serapilheira é o habitat natural para grande variedade de organismos, que diferem em tamanho e metabolismo, responsáveis por inúmeras funções. O monitoramento dos grupos de fauna no sistema solo-serapilheira permite não só uma inferência sobre a funcionalidade destes organismos, mas também uma indicação simples da complexidade ecológica dessas comunidades. O presente trabalho teve como objetivo caracterizar a distribuição da fauna edáfica nos compartimentos solo e serapilheira em duas épocas do ano e em cinco diferentes coberturas vegetais (eucalipto, floresta não preservada, floresta preservada, capoeira, pasto no Norte Fluminense. As coberturas de floresta natural, especialmente das florestas preservadas e não preservadas, mostraram, de maneira geral, valores de densidade e riqueza de fauna superiores aos de eucalipto e pasto, tanto no solo quanto na serapilheira, nas duas épocas de coleta. Em geral, não houve preferência dos grupos de fauna pelos compartimentos solo e serapilheira. A densidade de fauna, riqueza de espécies, índice de Shannon e índice de Pielou também variaram conforme a época de coleta, sendo, no verão, estabelecidas maiores diferenças entre as diferentes coberturas vegetais estudadas do que no inverno. O índice de Pielou foi a variável mais estável e, portanto, mais apropriada para o estudo da dissimilaridade entre as coberturas vegetais em termos de distribuição dos grupos de fauna.The soil-litter system is a natural habitat for a great variety of organisms that differ in size and metabolism and are responsible for numerous functions. The study of groups of organism in the soil-litter system allows not only to make inferences on the functionality of these organisms, but also is a simple indication of the ecological complexity in these communities. Our study aimed at characterizing the distribution of groups of organism in soil and litter compartments in two seasons of the year

  6. An Open-source Low-cost Portable Apparatus for Soil Fauna Sampling

    Science.gov (United States)

    Daliakopoulos, Ioannis; Wagner, Karl; Grillakis, Manolis; Apostolakis, Antonios; Tsanis, Ioannis

    2016-04-01

    A low-cost apparatus for the extraction of living soil animals from soil or litter samples is presented. The main unit consists of a modular bank system with three horizontal shelves designed to accommodate lamps and soil samples over funnel and jar systems for animal collection, thus serving as a practical and standardized modification of the well-documented Berlese-Tullgren funnel. Shelves are vertically adjustable, sliding on 5 mm threaded rods and securing with wing nuts for easy assembly/disassembly and stability. Shelf material is 4 mm plywood (or similar), laser-cut (or similar) to accommodate lamp sockets, tubes and funnels at respective levels. Soil samples are inserted in 10 cm tubes from standard Ø50 mm PVC piping that can also function as direct collection corers for softer soils. Tubes are fitted in the tube bank shelf, each directly under a 25 W reflector lamp and over a funnel and jar system. Lamps are located 25 mm over the tubes' top creating a relatively constant 10 oC temperature gradient that drives soil animals away from heat and light, and towards the bottom end of the tube which is fitted with a suitable fabric mesh. Standard 106 ml panelled jars, filled with a safe-to-handle preservative (e.g. propylene glycol) to the lower end of the funnel fitted in them, trap and preserve soil organisms until identification. The apparatus offers flat-pack portability and scalability using low-cost standard material. Design specifications and Drawing eXchange Format (dxf) files for apparatus reproduction are provided.

  7. Tillage system affects microbiological properties of soil

    Science.gov (United States)

    Delgado, A.; de Santiago, A.; Avilés, M.; Perea, F.

    2012-04-01

    Soil tillage significantly affects organic carbon accumulation, microbial biomass, and subsequently enzymatic activity in surface soil. Microbial activity in soil is a crucial parameter contributing to soil functioning, and thus a basic quality factor for soil. Since enzymes remain soil after excretion by living or disintegrating cells, shifts in their activities reflect long-term fluctuations in microbial biomass. In order to study the effects of no-till on biochemical and microbiological properties in comparison to conventional tillage in a representative soil from South Spain, an experiment was conducted since 1982 on the experimental farm of the Institute of Agriculture and Fisheries Research of Andalusia (IFAPA) in Carmona, SW Spain (37o24'07''N, 5o35'10''W). The soil at the experimental site was a very fine, montomorillonitic, thermic Chromic Haploxerert (Soil Survey Staff, 2010). A randomized complete block design involving three replications and the following two tillage treatments was performed: (i) Conventional tillage, which involved mouldboard plowing to a depth of 50 cm in the summer (once every three years), followed by field cultivation to a depth of 15 cm before sowing; crop residues being burnt, (ii) No tillage, which involved controlling weeds before sowing by spraying glyphosate and sowing directly into the crop residue from the previous year by using a planter with double-disk openers. For all tillage treatments, the crop rotation (annual crops) consisted of winter wheat, sunflower, and legumes (pea, chickpea, or faba bean, depending on the year), which were grown under rainfed conditions. Enzymatic activities (ß-glucosidase, dehydrogenase, aryl-sulphatase, acid phosphatase, and urease), soil microbial biomass by total viable cells number by acridine orange direct count, the density of cultivable groups of bacteria and fungi by dilution plating on semi-selective media, the physiological profiles of the microbial communities by BiologR, and the

  8. Biosolids applied to agricultural land: Influence on structural and functional endpoints of soil fauna on a short- and long-term scale.

    Science.gov (United States)

    Coors, Anja; Edwards, Mark; Lorenz, Pascale; Römbke, Jörg; Schmelz, Rüdiger M; Topp, Edward; Waszak, Karolina; Wilkes, Graham; Lapen, David R

    2016-08-15

    Biosolids have well-documented crop and soil benefits similar to other sources of organic amendment, but there is environmental concern due to biosolids-associated pollutants. The present study investigated two field sites that had received biosolids at commercial-scale rates in parallel to associated field sections which were managed similarly but without receiving biosolids (controls). The investigated endpoints were abundance and diversity of soil organisms (nematodes, enchytraeids and earthworms) and soil fauna feeding activity as measured by the bait lamina assay. Repeated sampling of one of the field sites following the only biosolids application demonstrated an enrichment effect typical for organic amendments, which was mostly exhausted after 44months. After an initial suppression, the proportion of free-living plant-parasitic nematodes tended to increase in the biosolids-amended soil over time. Yet, none of the endpoints at this site indicated significant negative effects resulting from the biosolids until 44months post application. In contrast to the repeatedly tilled first field site, the second one was left fallow after three biosolids applications, and was sampled 96months post last application. It was only at this field site that potential evidence for a long-term impact of biosolids was detected with regard to two endpoints: earthworm abundance and structure of the nematode assemblage. Agricultural management and correlation with abiotic soil parameters explained the observed difference in earthworm abundance. Yet, the development of a highly structured and mature nematode assemblage at the control but not at the biosolids-amended section of this fallow field could not be explained by such correlations nor by soil metal concentrations. Overall, the present study found only weak evidence for negative long-term impacts of biosolids applied at commercial rates on soil fauna. High-level community parameters such as the nematode structure index (SI

  9. Fauna of soil nematodes (Nematoda) in coal post-mining sites in Illinois, USA

    Czech Academy of Sciences Publication Activity Database

    Háněl, Ladislav

    2013-01-01

    Roč. 77, č. 2 (2013), s. 103-112. ISSN 1211-376X R&D Projects: GA MŠk ME08019 Institutional research plan: CEZ:AV0Z60660521 Institutional support: RVO:60077344 Keywords : soil zoology * ecology * Nematoda * species and generic richness * faunal similarity Subject RIV: EH - Ecology, Behaviour

  10. Fauna Data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Records of fauna (animals), and environmental change derived from animal fossils. Parameter keywords describe what was measured in this data set. Additional summary...

  11. Effect of leaf litter quantity and type on forest soil fauna and biological quality

    OpenAIRE

    Zhizhong Yuan; Yang Cui; Shaokui Yan

    2013-01-01

    It is important to assess forest litter management. Here we examined the effects of leaf litter addition on the soil faunal community in Huitong subtropical forest region in Hunan Province, China. The microcosm experiment involving leaf-litter manipulation using a block and nested experimental design, respectively, was established in May, 2011. In the block design, the effects of litter quantity and its control were examined, while in the nested design a comparison was made of litter quality ...

  12. Ectomycorrhizal activity as affected by soil liming

    Energy Technology Data Exchange (ETDEWEB)

    Andersson, Solbritt

    1996-05-01

    Acidification of the forest soils in southern Sweden due to atmospheric deposition has become evident during recent decades. To counteract further acidification, liming of forests in the most affected areas has been proposed. Most forest trees in the temperate and boreal forest ecosystems live in symbiosis with ectomycorrhizal fungi, and their uptake of mineral nutrients from the soil is greatly influenced by the symbiosis. In this thesis effects of liming on ectomycorrhiza have been studied in relation to effects on root colonization, fungal growth and nitrogen uptake. In field experiments the effects of liming on ectomycorrhizal colonization of root tips were variable, possibly due to different soil types and climatic variations. However, a changed mycorrhizal community structure could be detected. Laboratory studies also showed that the substrate may influence the outcome of lime applications; the nutrient status of the substrate had a marked effect on how mycelial growth was affected by liming. Under the experimental conditions used in the studies presented in this thesis, liming reduced the uptake of nitrogen and phosphorus by both mycorrhizal and non-mycorrhizal plants. The amount of extractable nitrogen and phosphorus in the peat was also reduced by liming. The latter could be due to either microbial or chemical immobilization. The lime induced decrease in nitrogen uptake was stronger in non-mycorrhizal plants than in mycorrhizal plants. Thus, the mycorrhizal plants had a higher ability to deal with the negative effects of liming on nitrogen availability. This was not the case for phosphorus. The lime induced decrease in phosphorus uptake was stronger for mycorrhizal plants, and in the highest lime treatment there was no significant difference between the mycorrhizal and the non-mycorrhizal spruce plants. 76 refs, 2 figs, 1 tab

  13. Integration of biodiversity in soil quality monitoring : baselines for microbial and soil fauna parameters for different land-use types

    OpenAIRE

    Cluzeau, D.; Guernion, M.; Chaussod, R.; Martin-Laurent, F.; Villenave, Cécile; Cortet, J.; Ruiz-Camacho, N.; Pernin, C.; Mateille, Thierry; Philippot, L.; Bellido, A.; Rouge, L.; Arrouays, D; Bispo, A; Peres, G

    2012-01-01

    The French programme Reseau de Mesures de la Qualite des Sols - Biodiversite was carried out at a regional scale (Brittany, west part of France) i) to produce a first statement regarding soil biodiversity, ii) to identify bioindicators of anthropic constraints, and iii) to determine baseline values for several biological groups depending on land uses. In this study, 109 monitoring sites were investigated using a systematic framework (a 16 km x 16 km regular grid). Six biological groups were s...

  14. Fauna europaea

    DEFF Research Database (Denmark)

    Pape, Thomas; Beuk, Paul; Pont, Adrian Charles; Shatalkin, Anatole I; Ozerov, Andrey L; Woźnica, Andrzej J; Merz, Bernhard; Bystrowski, Cezary; Raper, Chris; Bergström, Christer; Kehlmaier, Christian; Clements, David K; Greathead, David; Kameneva, Elena Petrovna; Nartshuk, Emilia; Petersen, Johan Frederik Torp; Weber, Gisela; Bächli, Gerhard; Geller-Grimm, Fritz; Van de Weyer, Guy; Tschorsnig, Hans-Peter; de Jong, Herman; van Zuijlen, Jan-Willem; Vaňhara, Jaromír; Roháček, Jindřich; Ziegler, Joachim; Majer, József; Hůrka, Karel; Holston, Kevin; Rognes, Knut; Greve-Jensen, Lita; Munari, Lorenzo; de Meyer, Marc; Pollet, Marc; Speight, Martin C D; Ebejer, Martin John; Martinez, Michel; Carles-Tolrá, Miguel; Földvári, Mihály; Chvála, Milan; Barták, Miroslav; Evenhuis, Neal L; Chandler, Peter J; Cerretti, Pierfilippo; Meier, Rudolf; Rozkosny, Rudolf; Prescher, Sabine; Gaimari, Stephen D; Zatwarnicki, Tadeusz; Zeegers, Theo; Dikow, Torsten; Korneyev, Valery A; Richter, Vera Andreevna; Michelsen, Verner; Tanasijtshuk, Vitali N; Mathis, Wayne N; Hubenov, Zdravko; de Jong, Yde

    2015-01-01

    Fauna Europaea provides a public web-service with an index of scientific names (including important synonyms) of all extant multicellular European terrestrial and freshwater animals and their geographical distribution at the level of countries and major islands (east of the Urals and excluding th...

  15. Contribution of Soil Fauna to Foliar Litter-Mass Loss in Winter in an Ecotone between Dry Valley and Montane Forest in the Upper Reaches of the Minjiang River.

    Directory of Open Access Journals (Sweden)

    Yan Peng

    Full Text Available Litter decomposition during winter can provide essential nutrients for plant growth in the subsequent growing season, which plays important role in preventing the expansion of dry areas and maintaining the stability of ecotone ecosystems. However, limited information is currently available on the contributions of soil fauna to litter decomposition during winter in such ecosystems. Therefore, a field experiment that included litterbags with two different mesh sizes (0.04 mm and 3 mm was conducted to investigate the contribution of soil fauna to the loss of foliar litter mass in winter from November 2013 to April 2014 along the upper reaches of the Minjiang River. Two litter types of the dominant species were selected in each ecosystem: cypress (Cupressus chengiana and oak (Quercus baronii in ecotone; cypress (Cupressus chengiana and clovershrub (Campylotropis macrocarpa in dry valley; and fir (Abies faxoniana and birch (Betula albosinensis in montane forest. Over one winter incubation, foliar litter lost 6.0%-16.1%, 11.4%-26.0%, and 6.4%-8.5% of initial mass in the ecotone, dry valley and montane forest, respectively. Soil fauna showed obvious contributions to the loss of foliar litter mass in all of the ecosystems. The highest contribution (48.5%-56.8% was observed in the ecotone, and the lowest contribution (0.4%-25.8% was observed in the montane forest. Compared with other winter periods, thawing period exhibited higher soil fauna contributions to litter mass loss in ecotone and dry valley, but both thawing period and freezing period displayed higher soil fauna contributions in montane forest. Statistical analysis demonstrated that the contribution of soil fauna was significantly correlated with temperature and soil moisture during the winter-long incubation. These results suggest that temperature might be the primary control factor in foliar litter decomposition, but more active soil fauna in the ecotone could contribute more in litter

  16. EFFECT OF ”KOMBA-KOMBA” PRUNING COMPOST AND PLANTING TIME OF MUNGBEAN IN INTERCROPPING WITH MAIZE ON YIELD AND SOIL FAUNA

    Directory of Open Access Journals (Sweden)

    Laode Sabaruddin

    2014-02-01

    Full Text Available Soil fauna plays an important role in decomposition and nutrient mineralization. The objective of this research was to study the effect of "komba-komba" compost and planting time of mungbean intercropped with maize on yield and soil fauna. The research was conducted in research station of Agricultural Faculty, Haluoleo University. The experiment was laid out using split plot design with two factors ("komba-komba" compost and planting time of mungbean intercropped with maize. The result indicated that the highest net assimilation rate (NAR of mungbean 5.78 g per cm2 per week was obtained in the komba-komba compost 10 ton per ha with planting time of mungbean at 14 days after planting (DAP maize whereas NAR of maize 5.50 g per cm2 per week was obtained in the planting time of mungbean at 14 DAP maize. Coleoptera and Hymenoptera (Formicidae were dominant and Shannon's diversity index ranged between 0.32 and 1.28. LER values tended to increase with the addition of "komba-komba" compost in soil and time variation of planting mungbean intercropped with maize. The relation between Shannon's diversity and LER values was variable.

  17. Soil Aeration Variability as Affected by Reoxidation

    Institute of Scientific and Technical Information of China (English)

    A.WOLI(N)SKA; Z.ST(E)PNIEWSKA

    2013-01-01

    The interplay between soil physical parameters during the recovery from anoxic stresses (reoxidation) is largely unrecognized.This study was conducted to characterise the soil aeration status and derive correlations between variable aeration factors during reoxidation.Surface layers (0-30 cm) of three soil types,Haplic Phaeozem,Mollic Gleysol,and Eutric Cambisol (FAO soil group),were selected for analysis.The moisture content was determined for a range of pF values (0,1.5,2.2,2.7,and 3.2),corresponding to the available water for microorganisms and plant roots.The variability of a number of soil aeration parameters,such as water potential (pF),air-filled porosity (Eg),oxygen diffusion rate (ODR),and redox potential (Eh),were investigated.These parameters were found to be interrelated in most cases.There were significant (P < 0.001) negative correlations of pF,Eg,and ODR with Eh.A decrease in water content as a consequence of soil reoxidation was manifested by an increase in the values of aeration factors in the soil environment.These results contributed to understanding of soil redox processes during recovery from flooding and might be useful for development of agricultural techniques aiming at soil reoxidation and soil fertility optimisation.

  18. Can transgenic maize affect soil microbial communities?

    Science.gov (United States)

    Mulder, Christian; Wouterse, Marja; Raubuch, Markus; Roelofs, Willem; Rutgers, Michiel

    2006-09-29

    The aim of the experiment was to determine if temporal variations of belowground activity reflect the influence of the Cry1Ab protein from transgenic maize on soil bacteria and, hence, on a regulatory change of the microbial community (ability to metabolize sources belonging to different chemical guilds) and/or a change in numerical abundance of their cells. Litter placement is known for its strong influence on the soil decomposer communities. The effects of the addition of crop residues on respiration and catabolic activities of the bacterial community were examined in microcosm experiments. Four cultivars of Zea mays L. of two different isolines (each one including the conventional crop and its Bacillus thuringiensis cultivar) and one control of bulk soil were included in the experimental design. The growth models suggest a dichotomy between soils amended with either conventional or transgenic maize residues. The Cry1Ab protein appeared to influence the composition of the microbial community. The highly enhanced soil respiration observed during the first 72 h after the addition of Bt-maize residues can be interpreted as being related to the presence of the transgenic crop residues. This result was confirmed by agar plate counting, as the averages of the colony-forming units of soils in conventional treatments were about one-third of those treated with transgenic straw. Furthermore, the addition of Bt-maize appeared to induce increased microbial consumption of carbohydrates in BIOLOG EcoPlates. Three weeks after the addition of maize residues to the soils, no differences between the consumption rate of specific chemical guilds by bacteria in soils amended with transgenic maize and bacteria in soils amended with conventional maize were detectable. Reaped crop residues, comparable to post-harvest maize straw (a common practice in current agriculture), rapidly influence the soil bacterial cells at a functional level. Overall, these data support the existence of short

  19. Can surfactants affect management of non-water repellent soils?

    Science.gov (United States)

    Surfactants affect the water relations of water repellent soils but may or may not affect those of wettable soils. We studied the effects of three surfactants, Aquatrols IrrigAid Gold®, an ethylene oxide/propylene oxide block copolymer, and an alkyl polyglycoside, along with untreated tap water as ...

  20. Chloride concentration affects soil microbial community

    Czech Academy of Sciences Publication Activity Database

    Gryndler, Milan; Rohlenová, Jana; Kopecký, Jan; Matucha, Miroslav

    2008-01-01

    Roč. 71, č. 7 (2008), s. 1401-1408. ISSN 0045-6535 R&D Projects: GA ČR GA526/05/0636 Institutional research plan: CEZ:AV0Z50200510; CEZ:AV0Z50380511 Keywords : soil chloride * terminal restriction fragments * soil microorganisms Subject RIV: EE - Microbiology, Virology Impact factor: 3.054, year: 2008

  1. Fauna Europaea

    DEFF Research Database (Denmark)

    Pape, Thomas; Beuk, Paul; Pont, Adrian Charles;

    2015-01-01

    Fauna Europaea provides a public web-service with an index of scientific names (including important synonyms) of all extant multicellular European terrestrial and freshwater animals and their geographical distribution at the level of countries and major islands (east of the Urals and excluding the...... population density, and the more fertile habitats are extensively cultivated. This has undoubtedly increased the extinction risk for numerous species of brachyceran flies, yet with the recent re-discovery of Thyreophoracynophila (Panzer), there are no known cases of extinction at a European level. However...

  2. Fauna Europaea

    DEFF Research Database (Denmark)

    Michelsen, Verner

    ,000 taxon names, including 145,000 accepted (sub)species, assembled by a large network of (>400) leading specialists, using advanced electronic tools for data collations with data quality assured through sophisticated validation routines. Fauna Europaea started in 2000 as an EC funded FP5 project and...... Europaea provides a public web portal at faunaeur.org with links to other key biodiversity services, is installed as a taxonomic backbone in wide range of biodiversity services and actively contributes to biodiversity informatics innovations in various initiatives and EC programs....

  3. The ash in forest fire affected soils control the soil losses. Part 1. The pioneer research

    Science.gov (United States)

    Cerdà, Artemi; Pereira, Paulo

    2013-04-01

    After forest fires, the ash and the remaining vegetation cover on the soil surface are the main protection against erosion agents. The control ash exert on runoff generation mechanism was researched during the 90's (Cerdà, 1998a; 1998b). This pioneer research demonstrated that after forest fires there is a short period of time that runoff and surface wash by water is controlled by the high infiltration rates achieved by the soil, which were high due to the effect of ash acting as a mulch. The research of Cerdà (1998a; 1998b) also contributed to demonstrate that runoff was enhanced four month later upon the wash of the ash by the runoff, but also due to the removal of ash due to dissolution and water infiltration. As a consequence of the ephemeral ash cover the runoff and erosion reached the peak after the removal of the ash (usually four month), and for two years the soil erosion reached the peak (Cerdà, 1998a). Research developed during the last decade shown that the ash and the litter cover together contribute to reduce the soil losses after the forest fire (Cerdà and Doerr, 2008). The fate of the ash is related to the climatic conditions of the post-fire season, as intense thunderstorms erode the ash layer and low intensity rainfall contribute to a higher infiltration rate and the recovery of the vegetation. Another, key factor found during the last two decades that determine the fate of the ash and the soil and water losses is the impact of the fauna (Cerdà and Doerr, 2010). During the last decade new techniques were developed to study the impact of ash in the soil system, such as the one to monitor the ash changes by means of high spatial resolution photography (Pérez Cabello et al., 2012), and laboratory approaches that show the impact of ash as a key factor in the soil hydrology throughout the control they exert on the soil water repellency (Bodí et al., 2012). Laboratory approaches also shown that the fire severity is a key factor on the ash chemical

  4. Ruzigrass affecting soil-phosphorus availability

    Directory of Open Access Journals (Sweden)

    Alexandre Merlin

    2013-12-01

    Full Text Available The objective of this work was to evaluate the effectiveness of ruzigrass (Urochloaruziziensis in enhancing soil-P availability in areas fertilized with soluble or reactive rock phosphates. The area had been cropped for five years under no-till, in a system involving soybean, triticale/black-oat, and pearl millet. Previously to the five-year cultivation period, corrective phosphorus fertilization was applied once on soil surface, at 0.0 and 80 kg ha-1 P2O5, as triple superphosphate or Arad rock phosphate. After this five-year period, plots received the same corrective P fertilization as before and ruzigrass was introduced to the cropping system in the stead of the other cover crops. Soil samples were taken (0-10 cm after ruzigrass cultivation and subjected to soil-P fractionation. Soybean was grown thereafter without P application to seed furrow. Phosphorus availability in plots with ruzigrass was compared to the ones with spontaneous vegetation for two years. Ruzigrass cultivation increased inorganic (resin-extracted and organic (NaHCO3 soil P, as well as P concentration in soybean leaves, regardless of the P source. However, soybean yield did not increase significantly due to ruzigrass introduction to the cropping system. Soil-P availability did not differ between soluble and reactive P sources. Ruzigrass increases soil-P availability, especially where corrective P fertilization is performed.

  5. 烘虫温度和时间对中小型土壤动物烘虫分离效果的影响%Baking Temperature and Time on the Effect of Soil Meso-and Micro-fauna Separation Results

    Institute of Scientific and Technical Information of China (English)

    铁烈华; 张林成; 冯茂松; 白文玉; 王玲; 何沛

    2015-01-01

    and 32 ℃ respectively,and the baking temperature of shallow soil had been better to control at 36℃,in order to getting the better separation results.The process of baking soil meso-and micro-fauna could be completed within 18 h at exactly the right temperature,and that was mainly fo-cused on the first 13 h,and 4 h latter,after beginning baking,the separation effects still re-mained high.Generally,variation of separation effect with baking temperature is a single pak curve,the baking temperature is too low or too high will affect the separation effect.When bak- ing temperature bellowed 35 ℃,the different of separation effect is also obvious.[Conclusion]The variation of separation effect with baking temperature generally showed a single peak curve, and the differences were significant,so it will affect the separation effects while the temperature is too low or too high.When baking temperature bellowed 35 ℃,the different of separation effect was also obvious.Baking separation effects have nothing to do with stand structure,but it relates to the depth of soil.There is no direct relationship between length of baking time and stand struc-ture and the soil fauna's abundance on per unit area.But there is a relationship between the sepa-ration effects of dry soil fauna baking and soil animals categories.When the separation results of deep dry and wet soil meso-and micro-fauna are best,the temperature are 34 ℃ and 32 ℃.But the shallow soil is best to control the baking temperature at 36 ℃,in order to getting the better separation results.The process of baking soil meso-and micro-fauna can be completed in 18 h,and it is mainly concentrated at front 13 h.

  6. Soil warming affects soil organic matter chemistry of all density fractions of a mountain forest soil

    Science.gov (United States)

    Schnecker, Jörg; Wanek, Wolfgang; Borken, Werner; Schindlbacher, Andreas

    2016-04-01

    Rising temperatures enhance microbial decomposition of soil organic matter (SOM) and increase thereby the soil CO2 efflux. Elevated microbial activity might differently affect distinct SOM pools, depending on their stability and accessibility. Soil fractions derived from density fractionation have been suggested to represent SOM pools with different turnover times and stability against microbial decomposition. We here investigated the chemical and isotopic composition of bulk soil and three different density fractions of forest soils from a long term warming experiment in the Austrian Alps. At the time of sampling the soils in this experiment had been warmed during the snow-free period for 8 consecutive years. During that time no thermal adaptation of the microbial community could be identified and CO2 release from the soil continued to be elevated by the warming treatment. Our results which included organic C content, total N content, δ13C, δ 14C, δ 15N and the chemical composition, identified by pyrolysis-GC/MS, showed no significant differences in bulk soil between warming treatment and control. The differences in the three individual fractions (free particulate organic matter, occluded particulate organic matter and mineral associated organic matter) were mostly small and the direction of warming induced change was variable with fraction and sampling depth. We did however find statistically significant effects of warming in all density fractions from 0-10 cm depth, 10-20 cm depth or both. Our results also including significant changes in the supposedly more stable mineral associated organic matter fraction where δ 13C values decreased at both sampling depths and the relative proportion of N-bearing compounds decreased at a sampling depth of 10-20 cm. All the observed changes can be attributed to an interplay of enhanced microbial decomposition of SOM and increased root litter input. This study suggests that soil warming destabilizes all density fractions of

  7. Structural relationships among vegetation, soil fauna and humus form in a subalpine forest ecosystem: a Hierarchical Multiple Factor Analysis (HMFA)

    OpenAIRE

    Bernier, Nicolas; F. Gillet

    2012-01-01

    Aboveground vegetation, four belowground fauna groups and humus composition have been analyzed in order to investigate the links between autotrophic and heterotrophic communities in a Norway-spruce mountain forest in Tours-en-Savoie (France). The aboveground plant community was recorded in small patches corresponding to contrasting microhabitats. Animal communities and humus layers were sampled within the same patches. The relationships between humus profile, faunistic and floristic compositi...

  8. Salt-affected soils of Russia: Solved and unsolved problems

    Science.gov (United States)

    Pankova, E. I.

    2015-02-01

    Data on salt-affected soils of Russia are analyzed. Three major problems of current research are outlined: (1) adequate diagnosis of soil salinization, (2) mapping and assessment of the areas of salt-affected soils, and (3) monitoring of the state of soil salinization. On the basis of recent publications, priority tasks and challenges for further research in this field are discussed. First, the notion of salt-affected soils should be specified with due respect for the diagnostic criteria of soil salinization. Second, in the assessment of these soils, not only the degree of salinization but also the chemistry of salts and the depth of the upper salt-bearing horizon should be taken into account. Third, to calculate the areas of salt-affected soils and to perform their monitoring, satellite images meeting specified requirements should be used. These requirements depend on the land use and cultivated crops. Modern technologies of the interpretation of satellite images should be applied for these purposes. Recent studies devoted to the monitoring of the salt status of irrigated and virgin soils of arid regions are discussed.

  9. Soil water repellency affects production and transport of CO2 and CH4 in soil

    Science.gov (United States)

    Urbanek, Emilia; Qassem, Khalid

    2016-04-01

    Soil moisture is known to be vital in controlling both the production and transport of C gases in soil. Water availability regulates the decomposition rates of soil organic matter by the microorganisms, while the proportion of water/air filled pores controls the transport of gases within the soil and at the soil-atmosphere interface. Many experimental studies and process models looking at soil C gas fluxes assume that soil water is uniformly distributed and soil is easily wettable. Most soils, however, exhibit some degree of soil water repellency (i.e. hydrophobicity) and do not wet spontaneously when dry or moderately moist. They have restricted infiltration and conductivity of water, which also results in extremely heterogeneous soil water distribution. This is a world-wide occurring phenomenon which is particularly common under permanent vegetation e.g. forest, grass and shrub vegetation. This study investigates the effect of soil water repellency on microbial respiration, CO2 transport within the soil and C gas fluxes between the soil and the atmosphere. The results from the field monitoring and laboratory experiments show that soil water repellency results in non-uniform water distribution in the soil which affects the CO2 and CH4 gas fluxes. The main conclusion from the study is that water repellency not only affects the water relations in the soil, but has also a great impact on greenhouse gas production and transport and therefore should be included as an important parameter during the sites monitoring and modelling of gas fluxes.

  10. Characteristics of Salt Affected Soil and Its Amelioration by Trees

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Salt-affected soils extensively distribute on the earth.Although the causes are various,generally speaking salinization occurrence results from the accumulation of free salts to an extent that causes degradation of vegetation and soils.Besides,irrational human practices have increased soil salinity by allowing excess recharging of groundwater to change the natural balance of the water cycle in the landscape. This reduces the suitability to plant growth and increases the potential for other forms of land ...

  11. Factors Affecting Sensitivity of Variable Charge Soils to Acid Rain

    Institute of Scientific and Technical Information of China (English)

    WANGJING-HUA

    1995-01-01

    The sensitivity of a large number of variable charge soils to acid rain was evaluated through examining pH-H2SO4 input curves.Two derivative parameters,the consumption of hydrogen ions by the soil and the acidtolerant limit as defined as the quantity of sulfuric acid required to bring the soil to pH 3.5 in a 0.001mol L-1 Ca(NO3)2 solution,were used.The sensitivity of variable charge soils was higher than that of constant charge soils,due to the predominance of kaolinite in clay mineralogical composition.Among these soils the sensitivity was generally of the order lateritic red soil>red soil> latosol.For a given type of soil within the same region the sensitivity was affected by parent material,due to differences in clay minerals and texture.The sensitivity of surface soil may be lower or higher than that of subsiol,depending on whether organic matter or texture plays the dominant role in determining the buffering capacity.Paddy soils consumed more acid within lower range of acid input when compared with upland soils,due to the presence of more exchangeable bases,but consumed less acid within higher acid input range,caused by the decrease in clay content.

  12. Factors Affecting Soil Microbial Community Structure in Tomato Cropping Systems

    Science.gov (United States)

    Soil and rhizosphere microbial communities in agroecosystems may be affected by soil, climate, plant species, and management. We identified some of the most important factors controlling microbial biomass and community structure in an agroecosystem utilizing tomato plants with the following nine tre...

  13. Factors Affecting Diffusion of Ions in Soils

    Institute of Scientific and Technical Information of China (English)

    LICHENG-BAO; YANGDING-QING

    1993-01-01

    In this work the diffusion coefficients of Na+,K+,Ca2+,NO3- and Cl- ions were estimated in terms of measuring apparent direct current (DC) conductivities of latosol,red soil and yellow-brown earth containing,respectively,NaNO3,NCl,and CaCl2 of different concentrations (0.005,0.05,0.10,and 0.15 mol/L) in the case of moisture contents ranging from wet to water saturation.The results showed that when bulk density,moisture content,and electrolyte concentration were constant,the diffusion coefficients of cations were in the order Na+>K+>Ca2+ except for Na+ and K+ in latosol,while the order for anions was NO3->Cl-.The diffusion coefficients (Di) of cations and anions were linearly proportional to volumetric moisture content (θ) as electrolyte concentration and bulk density were unchanged.When moisture content and bulk density were constant,the diffusion coefficients of cations decreased,to varying extents,with the increase of electrolyte concentration,and the decrement in different soils followed the order yellow-brown earth> red soil> latosol,but the decrement order of different cations was Na+>K+>Ca2+.

  14. Tuber Formation in Potatoes as Affected by Soil Moisture

    International Nuclear Information System (INIS)

    In potatoes, tuber formation is generally confined to the top 10 cm of the soil, while root development is concentrated in layers below this depth. An experiment was designed primarily to study how the soil-moisture climate of the ''tuber zone'' would affect potato growth. A common ''root zone'' was chosen by setting the seed tubers on the surface of a loam soil. On top of this a 10 cm soil layer was placed to act as a tuber zone. Soil texture and moisture were the factors used to establish four different physical environments of the applied top layer. Soil moisture was regulated throughout the growing season by means of the neutron method. Potato growth was studied by means of successively harvesting the treatment plots. Various growth development stages could be differentiated where the moisture climate had significant effects not only on the rate, but also on the nature of the growth and the state of health of the potato plants. (author)

  15. Burning management in the tallgrass prairie affects root decomposition, soil food web structure and carbon flow

    Science.gov (United States)

    Shaw, E. A.; Denef, K.; Milano de Tomasel, C.; Cotrufo, M. F.; Wall, D. H.

    2015-09-01

    Root litter decomposition is a major component of carbon (C) cycling in grasslands, where it provides energy and nutrients for soil microbes and fauna. This is especially important in grasslands where fire is a common management practice and removes aboveground litter accumulation. In this study, we investigated whether fire affects root decomposition and C flow through the belowground food web. In a greenhouse experiment, we applied 13C-enriched big bluestem (Andropogon gerardii) root litter to intact tallgrass prairie soil cores collected from annually burned (AB) and infrequently burned (IB) treatments at the Konza Prairie Long Term Ecological Research (LTER) site. Incorporation of 13C into microbial phospholipid fatty acids and nematode trophic groups was measured on six occasions during a 180-day decomposition study to determine how C was translocated through the soil food web. Results showed significantly different soil communities between treatments and higher microbial abundance for IB. Root decomposition occurred rapidly and was significantly greater for AB. Microbes and their nematode consumers immediately assimilated root litter C in both treatments. Root litter C was preferentially incorporated in a few groups of microbes and nematodes, but depended on burn treatment: fungi, Gram-negative bacteria, Gram-positive bacteria, and fungivore nematodes for AB and only omnivore nematodes for IB. The overall microbial pool of root litter-derived C significantly increased over time but was not significantly different between burn treatments. The nematode pool of root litter-derived C also significantly increased over time, and was significantly higher for the AB treatment at 35 and 90 days after litter addition. In conclusion, the C flow from root litter to microbes to nematodes is not only measurable, but significant, indicating that higher nematode trophic levels are critical components of C flow during root decomposition which, in turn, is significantly

  16. Key soil functional properties affected by soil organic matter - evidence from published literature

    Science.gov (United States)

    Murphy, Brian

    2015-07-01

    The effect of varying the amount of soil organic matter on a range of individual soil properties was investigated using a literature search of published information largely from Australia, but also included relevant information from overseas. Based on published pedotransfer functions, soil organic matter was shown to increase plant available water by 2 to 3 mm per 10 cm for each 1% increase in soil organic carbon, with the largest increases being associated with sandy soils. Aggregate stability increased with increasing soil organic carbon, with aggregate stability decreasing rapidly when soil organic carbon fell below 1.2 to 1.5 5%. Soil compactibility, friability and soil erodibility were favourably improved by increasing the levels of soil organic carbon. Nutrient cycling was a major function of soil organic matter. Substantial amounts of N, P and S become available to plants when the soil organic matter is mineralised. Soil organic matter also provides a food source for the microorganisms involved in the nutrient cycling of N, P, S and K. In soils with lower clay contents, and less active clays such as kaolinites, soil organic matter can supply a significant amount of the cation exchange capacity and buffering capacity against acidification. Soil organic matter can have a cation exchange capacity of 172 to 297 cmol(+)/kg. As the cation exchange capacity of soil organic matter varies with pH, the effectiveness of soil organic matter to contribute to cation exchange capacity below pH 5.5 is often minimal. Overall soil organic matter has the potential to affect a range of functional soil properties.

  17. Fractionation of Heavy Metals in Soils as Affected by Soil Types and Metal Load Quantity

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Two series of soil subsamples, by spiking copper (Cu), lead (Pb), zinc (Zn) and cadmium (Cd) in anorthogonal design, were prepared using red soil and brown soil, respectively. The results indicated that heavymetal fractions in these soil subsamples depended not only on soil types, but also on metal loading quantityas well as on interactions among metals in soil. Lead and Cu in red soil appeared mostly in weakly specificallyadsorbed (WSA), Fe and Mn oxides bound (OX), and residual (RES) fractions. Zinc existed in all fractionsexcept organic bound one, and Cd was major in water soluble plus exchangeable (SE) one. Different fromthe results of red soil, Pb and Cu was present in brown soil in all fractions except organic one, but over 75%of Zn and 90% of Cd existed only in SE fraction. Meanwhile, SE fraction for any metal in red soil was lowerthan that in brown soil and WSA and OX fractions were higher. It is in agreement with low cation exchangecapacity and large amounts of metal oxides included in red soil. Metal fractions in soil, especially for watersoluble plus exchangeable one, were obviously influenced by other coexisting metals. The SE fraction ofheavy metals increased with increasing loading amounts of metals in red soil but not obviously in brown soil,which suggest that metal availability be easily affected by their total amounts spiked in red soil. In addition,more metals in red soil were extracted with 0.20 mol L-1 NH4Cl (pH 5.40) than that with 1.0 mol L-1Mg(NO3)2 (pH 7.0), but the reverse happened in brown soil, implicating significantly different mechanismsof metal desorption from red soil and brown soil.

  18. Physical properties of magnesium affected soils in Colombia

    International Nuclear Information System (INIS)

    Magnesium has some capacity to develop higher exchangeable sodium levels in clays and soil materials. The Mg+2 accumulation on the exchange complex of soils to a very high saturation levels affect their physical, chemical and biological properties. Colombia has a large area of these soils, located mainly in the main rivers valleys and in the Caribbean Region. In the Cauca River Valley there are about 117,000 hectares affected. There is a lack of information about the soil forming processes, the Mg+2 effects on soils, the type and source of compounds responsible for the magnesium enrichment, their relationship with the landscape and the way this accumulation occurs. To identify and quantify soil Mg+2 enriched areas over 2500 soil profiles from different landscape positions of the Cauca River Valley were studied. The information was processed to generate Mg-saturation maps, to identify the different soil profile types and to estimate the affected area. A topographic sequence from the alluvial inundation plain to the hills was used to explore the presence of diagnostic horizons and to determine the main soil characteristics and genetic, mineralogical or chemical evidences of soil forming processes. Two 180 kilometer transects parallel to the river were used to: a) study the type and source of Mg-compounds responsible for the Mg-enrichment and the way this accumulation occurs. b) the soil hydraulic properties like infiltration, saturated hydraulic conductivity and matrix potential at different depths were also measured. Samples of nine profiles were collected and the porosity and soil volume changes at different water content were examined. The program RETC was used for prediction of the hydraulic properties of non saturated soils. These properties involved the retention curve, the function of hydraulic conductivity and the diffusivity of the water in the soil. By grouping together the soil profiles, five main type of Mg-affected soils were identified as being

  19. Bacterial Communities in Malagasy Soils with Differing Levels of Disturbance Affecting Botanical Diversity

    OpenAIRE

    Blasiak, Leah C.; Schmidt, Alex W.; Andriamiarinoro, Honoré; Mulaw, Temesgen; Rasolomampianina, Rado; Wendy L Applequist; Birkinshaw, Chris; Rejo-Fienena, Félicitée; Lowry, Porter P.; Schmidt, Thomas M; Hill, Russell T.

    2014-01-01

    Madagascar is well-known for the exceptional biodiversity of its macro-flora and fauna, but the biodiversity of Malagasy microbial communities remains relatively unexplored. Understanding patterns of bacterial diversity in soil and their correlations with above-ground botanical diversity could influence conservation planning as well as sampling strategies to maximize access to bacterially derived natural products. We present the first detailed description of Malagasy soil bacterial communitie...

  20. Genetic by environment interactions affect plant–soil linkages

    OpenAIRE

    Pregitzer, Clara C; Joseph K Bailey; Schweitzer, Jennifer A.

    2013-01-01

    The role of plant intraspecific variation in plant–soil linkages is poorly understood, especially in the context of natural environmental variation, but has important implications in evolutionary ecology. We utilized three 18- to 21-year-old common gardens across an elevational gradient, planted with replicates of five Populus angustifolia genotypes each, to address the hypothesis that tree genotype (G), environment (E), and G × E interactions would affect soil carbon and nitrogen dynamics be...

  1. Effects of sewage sludge addition to Norway spruce seedlings on nitrogen availability and soil fauna in clear-cut areas

    International Nuclear Information System (INIS)

    Anaerobically digested and composted sewage sludge (CSS) has been suggested to be a slow-release fertilizer in forestry and an alternative to quick-release inorganic fertilizers. The effects of CSS with or without added carbohydrate on inorganic nitrogen availability and on soil animals were tested in two Norway spruce plantations. Half of the seedlings were individually fertilized with CSS, and the rest were left as controls. Solid sucrose was added to half of the fertilized and untreated seedlings. Soil samples were taken in the autumn in the first and the second year after the treatments. CSS increased soil NH4–N (2100%), the proportion of soil NO3–N, and the N concentration of spruce needles. CSS greatly reduced the abundances of enchytraeids, tardigrades and collembolans, but increased the proportion and abundance of bacterial-feeding nematodes irrespective of carbohydrate addition. A better stabilization method needs to be developed before CSS can be used as a forest fertilizer. -- Highlights: •Spruces were fertilized with anaerobically digested and composted sewage sludge (CSS). •CSS increased soil N, proportion of NO3–N, and N concentration of spruce needles. •CSS reduced the abundances of enchytraeids, tardigrades and collembolans. •CSS increased the proportion and abundance of bacterial-feeding nematodes. •Sucrose did not reduce N pools or counteract negative CSS effects on soil animals. -- Composting and carbohydrate addition do not mitigate the harmful effects of anaerobically digested sewage sludge in boreal forest soil

  2. Fire affects root decomposition, soil food web structure, and carbon flow in tallgrass prairie

    Science.gov (United States)

    Shaw, E. Ashley; Denef, Karolien; Milano de Tomasel, Cecilia; Cotrufo, M. Francesca; Wall, Diana H.

    2016-05-01

    Root litter decomposition is a major component of carbon (C) cycling in grasslands, where it provides energy and nutrients for soil microbes and fauna. This is especially important in grasslands where fire is common and removes aboveground litter accumulation. In this study, we investigated whether fire affects root decomposition and C flow through the belowground food web. In a greenhouse experiment, we applied 13C-enriched big bluestem (Andropogon gerardii) root litter to intact tallgrass prairie soil cores collected from annually burned (AB) and infrequently burned (IB) treatments at the Konza Prairie Long Term Ecological Research (LTER) site. Incorporation of 13C into microbial phospholipid fatty acids and nematode trophic groups was measured on six occasions during a 180-day decomposition study to determine how C was translocated through the soil food web. Results showed significantly different soil communities between treatments and higher microbial abundance for IB. Root decomposition occurred rapidly and was significantly greater for AB. Microbes and their nematode consumers immediately assimilated root litter C in both treatments. Root litter C was preferentially incorporated in a few groups of microbes and nematodes, but depended on burn treatment: fungi, Gram-negative bacteria, Gram-positive bacteria, and fungivore nematodes for AB and only omnivore nematodes for IB. The overall microbial pool of root-litter-derived C significantly increased over time but was not significantly different between burn treatments. The nematode pool of root-litter-derived C also significantly increased over time, and was significantly higher for the AB treatment at 35 and 90 days after litter addition. In conclusion, the C flow from root litter to microbes to nematodes is not only measurable but also significant, indicating that higher nematode trophic levels are critical components of C flow during root decomposition, which, in turn, is significantly affected by fire. Not

  3. Composition and seasonal dynamics of soil fauna at jujube forest in Northern region of Shaanxi%陕北枣林土壤动物组成与季节动态

    Institute of Scientific and Technical Information of China (English)

    刘长海; 骆有庆; 陈宗礼; 廉振民

    2011-01-01

    目的 探讨枣林生态系统不同季节对土壤动物群落结构特征的影响,为枣林健康及其害虫生态调控提供基础资料.方法 选取延安万花山、延川县、清涧县、佳县4个样点7个样地,分别于2007年3,6,9,11月对陕北枣林土壤动物进行调查,通过手拣方法、干漏斗法和湿漏斗法采集和分离土壤动物.结果 获得4 029只土壤动物,属于22目;从枣林不同季节土壤动物群落多样性重要指标来分析,四季的交替对土壤动物群落组成、数量及多样性产生影响.结论 陕北枣林土壤动物群落多样性的四季变化为:秋季>夏季>春季>冬季.%Aim To study the impact of different seasons in jujube forest ecosystems in terms of composition and dynamics of soil fauna, and to provide basic data for jujube health and ecological regulation of pests. Methods The acquisition of macro-soil-fauna was mainly by hand-sorting. The dry funnel and wet funnel were separately used for separating and extracting meso-micro soil fauna, at 7 plots of 4 sample points, including Yan' an Wanhua Mountain, Yanchuan County, Qingjian County, Jia County, in March, June, September and November in 2007. Results 4 029 soil animals diversity have been identified, which belong to 22 orders. The analysis which is about diversity important indexes of soil fauna in different seasons of jujube forest shows that the succession of four seasons has influence on the composition, quantity and diversity of soil fauna community. Conclusion The seasonal change pattern of diversity of soil fauna groups of jujube forest in Northern area of Shaanxi is: autumn > summer > spring > winter.

  4. Risk characterization and remedial management of TPH-affected soils

    International Nuclear Information System (INIS)

    A risk-based remedial program for petroleum hydrocarbon affected soils has been implemented at a large land parcel in California. The site is the former location of a manufacturing facility that had been in operation since the 1940s. As a result of various activities related to parts manufacturing, several large areas of soil were found to contain various petroleum products. The primary sources of petroleum hydrocarbons included cutting oils, lubricating oils, fuels, and hydraulic oils associated with the site operations. Concentrations of total petroleum hydrocarbons (TPH) as high as 100,000 mg/kg were identified in soil. These high concentrations of TPH were identified at depths up to 60 feet below ground surface (bgs), with the vadose zone extending to depths of more than 150 feet bgs. Within California, traditional cleanup levels for TPH-affected soils typically range from 100 to 1,000 mg/kg. Because of the client's desire to sell the property for rapid development, the remedial alternative of excavation and off-haul was deemed too time consuming and costly. The estimated costs associated with this remediation which potentially involved soil removal to 100--120 feet exceeded $20 million and could take up to one year to complete. To meet the schedule requirements for site remediations as well as significantly reduce the overall project cost, the authors undertook a risk-based approach to assess if remediation of the TPH-affected soils was required

  5. Effects of sewage sludge addition to Norway spruce seedlings on nitrogen availability and soil fauna in clear-cut areas.

    Science.gov (United States)

    Nieminen, Jouni K; Räisänen, Mikko

    2013-07-01

    Anaerobically digested and composted sewage sludge (CSS) has been suggested to be a slow-release fertilizer in forestry and an alternative to quick-release inorganic fertilizers. The effects of CSS with or without added carbohydrate on inorganic nitrogen availability and on soil animals were tested in two Norway spruce plantations. Half of the seedlings were individually fertilized with CSS, and the rest were left as controls. Solid sucrose was added to half of the fertilized and untreated seedlings. Soil samples were taken in the autumn in the first and the second year after the treatments. CSS increased soil NH4-N (2100%), the proportion of soil NO3-N, and the N concentration of spruce needles. CSS greatly reduced the abundances of enchytraeids, tardigrades and collembolans, but increased the proportion and abundance of bacterial-feeding nematodes irrespective of carbohydrate addition. A better stabilization method needs to be developed before CSS can be used as a forest fertilizer. PMID:23603467

  6. Pesticide interactions with soils affected by olive oil mill wastewater

    Science.gov (United States)

    Keren, Yonatan; Bukhanovsky, Nadezhda; Borisover, Mikhail

    2013-04-01

    Soil pesticide sorption is well known to affect the fate of pesticides, their bioavailability and the potential to contaminate air and water. Soil - pesticide interactions may be strongly influenced by soil organic matter (SOM) and organic matter (OM)-rich soil amendments. One special OM source in soils is related to olive oil production residues that may include both solid and liquid wastes. In the Mediterranean area, the olive oil production is considered as an important field in the agricultural sector. Due to the significant rise in olive oil production, the amount of wastes is growing respectively. Olive oil mill waste water (OMWW) is the liquid byproduct in the so-called "three phase" technological process. Features of OMWW include the high content of fatty aliphatic components and polyphenols and their often-considered toxicity. One way of OMWW disposal is the land spreading, e.g., in olive orchards. The land application of OMWW (either controlled or not) is supposed to affect the multiple soil properties, including hydrophobicity and the potential of soils to interact with pesticides. Therefore, there is both basic and applied interest in elucidating the interactions between organic compounds and soils affected by OMWW. However, little is known about the impact of OMWW - soil interactions on sorption of organic compounds, and specifically, on sorption of agrochemicals. This paper reports an experimental study of sorption interactions of a series of organic compounds including widely used herbicides such as diuron and simazine, in a range of soils that were affected by OMWW (i) historically or (ii) in the controlled land disposal experiments. It is demonstrated that there is a distinct increase in apparent sorption of organic chemicals in soils affected by OMWW. In selected systems, this increase may be explained by increase in SOM content. However, the SOM quality places a role: the rise in organic compound - soil interactions may both exceed the SOM

  7. Spatial heterogeneity of soil biochar content affects soil quality and wheat growth and yield.

    Science.gov (United States)

    Olmo, Manuel; Lozano, Ana María; Barrón, Vidal; Villar, Rafael

    2016-08-15

    Biochar (BC) is a carbonaceous material obtained by pyrolysis of organic waste materials and has been proposed as a soil management strategy to mitigate global warming and to improve crop productivity. Once BC has been applied to the soil, its imperfect and incomplete mixing with soil during the first few years and the standard agronomic practices (i.e. tillage, sowing) may generate spatial heterogeneity of the BC content in the soil, which may have implications for soil properties and their effects on plant growth. We investigated how, after two agronomic seasons, the spatial heterogeneity of olive-tree prunings BC applied to a vertisol affected soil characteristics and wheat growth and yield. During the second agronomic season and just before wheat germination, we determined the BC content in the soil by an in-situ visual categorization based on the soil darkening, which was strongly correlated to the BC content of the soil and the soil brightness. We found a high spatial heterogeneity in the BC plots, which affected soil characteristics and wheat growth and yield. Patches with high BC content showed reduced soil compaction and increased soil moisture, pH, electrical conductivity, and nutrient availability (P, Ca, K, Mn, Fe, and Zn); consequently, wheat had greater tillering and higher relative growth rate and grain yield. However, if the spatial heterogeneity of the soil BC content had not been taken into account in the data analysis, most of the effects of BC on wheat growth would not have been detected. Our study reveals the importance of taking into account the spatial heterogeneity of the BC content. PMID:27110980

  8. The Stability of Unsaturated Soil Slope Affected by Rainfall Seeping

    Institute of Scientific and Technical Information of China (English)

    Zhang Shilin; Wang Guochen; Shao Longtan

    2007-01-01

    Because rainfall seeping makes losing stability of unsaturated soil slope, and arouses great loss to production and human being safety, the stability of unsaturated soil slope has been researched by many scholars recently. This article mainly uses the model for the prediction of shear strength with respect to soil suction, developed by Vanapalli and Fredlund to formulate rainfall seeping how to affect the stability of unsaturated soil slope. Firstly, volumetric water content of unsaturated soil slope changes with rainfall duration, and effective saturation changes with its volumetric water content. Secondly, soil volume weight changes with its volumetric water content. Thirdly, matric suction also changes with its volumetric water content. According to these causes, this article researches how much they make the contribution to the minimum safety coefficient respectively. At last, these factors roundly considered, this article gets the rule of minimum safety coefficient of unsaturated soil slope with rainfall duration that is minimum safety coefficient gradually increasing firstly, then decreasing that is composed of two sectors, first is slowly decreasing, then is fast decreasing after some value.

  9. Use of Contour Maps of Water Depths to Predict Flora and Fauna Abundance in Moist Soil Management

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The goal of this project was to develop a technique to quantitatively predict the area of moist soil that would be exposed as a result of a water drawdown of any...

  10. The effect of topsoil removal in restored heathland on soil fauna, topsoil microstructure, and cellulose decomposition: implications for ecosystem restoration

    Czech Academy of Sciences Publication Activity Database

    Frouz, Jan; van Diggelen, R.; Pižl, Václav; Starý, Josef; Háněl, Ladislav; Tajovský, Karel; Kalčík, Jiří

    2009-01-01

    Roč. 18, č. 14 (2009), s. 3963-3978. ISSN 0960-3115 Institutional research plan: CEZ:AV0Z60660521 Keywords : restoration * soil formation * oribatid mites Subject RIV: EH - Ecology, Behaviour Impact factor: 2.066, year: 2009

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

    Directory of Open Access Journals (Sweden)

    Patricia Pértile

    2016-01-01

    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

  12. Prolonged Soil Frost Affects Hydraulics and Phenology of Apple Trees.

    Science.gov (United States)

    Beikircher, Barbara; Mittmann, Claudia; Mayr, Stefan

    2016-01-01

    Restoration of an adequate water supply in spring is a prerequisite for survival of angiosperm trees in temperate regions. Trees must re-establish access to soil water and recover xylem functionality. We thus hypothesized that prolonged soil frost impairs recovery and affects hydraulics and phenology of Malus domestica var. 'Golden Delicious.' To test this hypothesis, over two consecutive winters the soil around some trees was insulated to prolong soil frosting, From mid-winter to early summer, the level of native embolism, the water and starch contents of wood, bark and buds were quantified at regular intervals and findings correlated with various phenological parameters, xylogenesis and fine root growth. The findings confirm that prolonged soil frost affects tree hydraulics and phenology but the severity of the effect depends on the climatic conditions. In both study years, percentage loss of hydraulic conductivity (PLC) decreased from about 70% at the end of winter to about 10% in May. Thereby, xylem refilling strongly coincided with a decrease of starch in wood and bark. Also treated trees were able to restore their hydraulic system by May but, in the warm spring of 2012, xylem refilling, the increases in water content and starch depolymerization were delayed. In contrast, in the cold spring of 2013 only small differences between control and treated trees were observed. Prolongation of soil frost also led to a delay in phenology, xylogenesis, and fine root growth. We conclude that reduced water uptake from frozen or cold soils impairs refilling and thus negatively impacts tree hydraulics and growth of apple trees in spring. Under unfavorable circumstances, this may cause severe winter damage or even dieback. PMID:27379146

  13. Green roof soil system affected by soil structural changes: A project initiation

    Science.gov (United States)

    Jelínková, Vladimíra; Dohnal, Michal; Šácha, Jan; Šebestová, Jana; Sněhota, Michal

    2014-05-01

    Anthropogenic soil systems and structures such as green roofs, permeable or grassed pavements comprise appreciable part of the urban watersheds and are considered to be beneficial regarding to numerous aspects (e.g. carbon dioxide cycle, microclimate, reducing solar absorbance and storm water). Expected performance of these systems is significantly affected by water and heat regimes that are primarily defined by technology and materials used for system construction, local climate condition, amount of precipitation, the orientation and type of the vegetation cover. The benefits and potencies of anthropogenic soil systems could be considerably threatened in case when exposed to structural changes of thin top soil layer in time. Extensive green roof together with experimental green roof segment was established and advanced automated monitoring system of micrometeorological variables was set-up at the experimental site of University Centre for Energy Efficient Buildings as an interdisciplinary research facility of the Czech Technical University in Prague. The key objectives of the project are (i) to characterize hydraulic and thermal properties of soil substrate studied, (ii) to establish seasonal dynamics of water and heat in selected soil systems from continuous monitoring of relevant variables, (iii) to detect structural changes with the use of X-ray Computed Tomography, (iv) to identify with the help of numerical modeling and acquired datasets how water and heat dynamics in anthropogenic soil systems are affected by soil structural changes. Achievements of the objectives will advance understanding of the anthropogenic soil systems behavior in conurbations with the temperate climate.

  14. Climate change affects carbon allocation to the soil in shrublands

    DEFF Research Database (Denmark)

    Gorissen, A.; Tietema, A.; Joosten, N.N.;

    2004-01-01

    Climate change may affect ecosystem functioning through increased temperatures or changes in precipitation patterns. Temperature and water availability are important drivers for ecosystem processes such as photosynthesis, carbon translocation, and organic matter decomposition. These climate changes...... may affect the supply of carbon and energy to the soil microbial population and subsequently alter decomposition and mineralization, important ecosystem processes in carbon and nutrient cycling. In this study, carried out within the cross-European research project CLIMOOR, the effect of climate change...... in the growing season. Differences in climate, soil, and plant characteristics resulted in a gradient in the severity of the drought effects on net carbon uptake by plants with the impact being most severe in Spain, followed by Denmark, with the UK showing few negative effects at significance levels of p less...

  15. Fauna of soil nematodes and other soil micro-mesofauna in spruce clearings in the Šumava Mts., Czech Republic

    Czech Academy of Sciences Publication Activity Database

    Háněl, Ladislav

    České Budějovice : Institute of Soil Biology AS CR, 2001. s. 43. [Central European Workshop on Soil Zoology /6./. 23.04.2001-25.04.2001, České Budějovice] Institutional research plan: CEZ:AV0Z6066911 Subject RIV: EH - Ecology, Behaviour

  16. How will climate change affect vine behaviour in different soils?

    Science.gov (United States)

    Leibar, Urtzi; Aizpurua, Ana; Morales, Fermin; Pascual, Inmaculada; Unamunzaga, Olatz

    2014-05-01

    and water-deficit had a clear influence on the grape phenological development and composition, whilst soil affected root configuration and anthocyanins concentration. Effects of climate change and water availability on different soil conditions should be considered to take full advantage or mitigate the consequences of the future climate conditions.

  17. Effect of biosolid waste compost on soil respiration in salt-affected soils

    Science.gov (United States)

    Raya, Silvia; Gómez, Ignacio; García, Fuensanta; Navarro, José; Jordán, Manuel Miguel; Belén Almendro, María; Martín Soriano, José

    2013-04-01

    A great part of mediterranean soils are affected by salinization. This is an important problem in semiarid areas increased by the use of low quality waters, the induced salinization due to high phreatic levels and adverse climatology. Salinization affects 25% of irrigated agriculture, producing important losses on the crops. In this situation, the application of organic matter to the soil is one of the possible solutions to improve their quality. The main objective of this research was to asses the relation between the salinity level (electrical conductivity, EC) in the soil and the response of microbial activity (soil respiration rate) after compost addition. The study was conducted for a year. Soil samples were collected near to an agricultural area in Crevillente and Elche, "El Hondo" Natural Park (Comunidad de Regantes from San Felipe Neri). The experiment was developed to determine and quantify the soil respiration rate in 8 different soils differing in salinity. The assay was done in close pots -in greenhouse conditions- containing soil mixed with different doses of sewage sludge compost (2, 4 and 6%) besides the control. They were maintained at 60% of water holding capacity (WHC). Soil samples were analyzed every four months for a year. The equipment used to estimate the soil respiration was a Bac-Trac and CO2 emitted by the soil biota was measured and quantified by electrical impedance changes. It was observed that the respiration rate increases as the proportion of compost added to each sample increases as well. The EC was incremented in each sampling period from the beginning of the experiment, probably due to the fact that soils were in pots and lixiviation was prevented, so the salts couldńt be lost from soil. Over time the compost has been degraded and, it was more susceptible to be mineralized. Salts were accumulated in the soil. Also it was observed a decrease of microbial activity with the increase of salinity in the soil. Keywords: soil

  18. Copper phytoavailability and uptake by Elsholtzia splendens from contaminated soil as affected by soil amendments.

    Science.gov (United States)

    Peng, Hong-Yun; Yang, Xiao-E; Jiang, Li-Ying; He, Zhen-Li

    2005-01-01

    Pot and field experiments were conducted to evaluate bioavailability of Cu in contaminated paddy soil (PS) and phytoremediation potential by Elsholtzia splendens as affected by soil amendments. The results from pot experiment showed that organic manure (M) applied to the PS not only remarkably raised the H2O exchangeable Cu, which were mainly due to the increased exchangeable and organic fractions of Cu in the PS by M, but also stimulated plant growth and Cu accumulation in E. splendens. At M application rate of 5.0%, shoot Cu concentration in the plant increased by four times grown on the PS, so as to the elevated shoot Cu accumulation by three times as compared to the control. In the field trial, soil amendments by M and furnace slag (F), and soil preparations like soil capping (S) and soil discing (D) were performed in the PS. Soil capping and discing considerably declined total Cu in the PS. Application of M solely or together with F enhanced plant growth and increased H2O exchangeable Cu levels in the soil. The increased extractability of Cu in the rhizosphere of E. splendens was noted, which may have mainly attributed to the rhizospheric acidification and chelation by dissolved organic matter (DOM), thus resulting in elevating Cu uptake and accumulation by E. splendens. Amendments with organic manure plus furnace slag (MF) to the PS caused the highest exactable Cu with saturated H2O in the rhizospheric soil of E. splendens after they were grown for 170 days in the PS, thus achieving 1.74 kg Cu ha(-1) removal from the contaminated soil by the whole plant of E. splendens at one season, which is higher than those of the other soil treatments. The results indicated that application of organic manure at a proper rate could enhance Cu bioavailability and increase effectiveness of Cu phytoextraction from the contaminated soil by the metal-tolerant and accumulating plant species (E. splendens). PMID:15792303

  19. Factors affecting potassium fixation in seven soils under 15-year long-term fertilization

    Institute of Scientific and Technical Information of China (English)

    ZHANG HuiMin; XU MingGang; ZHANG WenJu; HE XinHua

    2009-01-01

    Potassium (K) fixation by seven soils, including black soil, fluvo-aquic soil, grey desert soil, loess soil, paddy soil, red soil and purple soil, was determined by laboratory simulation under a fifteen-year-pe-riod of long-term fertilization. Factors affecting soil K fixation were then discussed by factor analysis and stepwise regression. Magnitude of soil K fixation rate was as follows: the black soil > the purple soil > the loess soil > the fluvo-aquic soil > the paddy soil > the grey desert soil > the red soil. Our re-sulta showed that soil K fixation capacity was significantly affected by the clay mineral types in the soils. Potassium fixation capacity of soils, whose 2:1 layer silicates were dominant minerals, was af-fected by two components extracted by the method of principal component analysis: the first including soil available K, slow available K and K+ saturation, and the second including cation exchange capacity (CEC), soil organic matter (SOM) and <0.002 mm clay contents. Potassium fixation rate was mainly af-fected by K+ saturation and CEC with lower added K concentration (from 0.4 to 1.6 g/L), and by K+ saturation and <0.002 mm clay content with higher added K concentration (from 2.4 to 4.0 g/L).

  20. Fauna del suelo en bosques y cafetales de la Sierra Nevada de Santa Marta, Colombia Soil fauna in forest and coffee plantations from the Sierra Nevada de Santa Marta, Colombia

    OpenAIRE

    Camero R. Edgar

    2002-01-01

    En la Sierra Nevada de Santa Marta se establecieron dos estaciones de muestreo en las localidades de Minca a 700 m de altitud y María Teresa a 790 m, para realizar comparaciones de la fauna asociada a los suelos de plantaciones de café y de bosques naturales. Las colecciones se realizaron tanto en la hojarasca como en los horizontes  subsuperficiales O, Ay B de las dos coberturas vegetales mediante el empleo de trampas Pitfall y Berlesse y se utilizaron índices d...

  1. Fauna of soil nematodes and other soil micro-mesofauna in spruce clearings in the Šumava Mts., Czech Republic

    Czech Academy of Sciences Publication Activity Database

    Háněl, Ladislav

    České Budějovice : Institute of Soil Biology AS CR, 2002, s. 45-49. ISBN 80-86525-00-7. [Central European Workshop on Soil Zoology /6./. České Budějovice (CZ), 23.04.2001-25.04.2001] R&D Projects: GA ČR GA206/99/1416 Institutional research plan: CEZ:AV0Z6066911 Keywords : Nematoda * Enchytraeidae * spruce clearings Subject RIV: EH - Ecology, Behaviour

  2. Soil hydraulic properties of topsoil along two elevation transects affected by soil erosion

    Science.gov (United States)

    Nikodem, Antonin; Kodesova, Radka; Jaksik, Ondrej; Jirku, Veronika; Fer, Miroslav; Klement, Ales; Zigova, Anna

    2013-04-01

    This study is focused on the comparison of soil hydraulic properties of topsoil that is affected by erosion processes. Studied area is characterized by a relatively flat upper part, a tributary valley in the middle and a colluvial fan at the bottom. Haplic Chernozem reminded at the flat upper part of the area. Regosols were formed at steep parts of the valley. Colluvial Chernozem and Colluvial soils were formed at the bottom parts of the valley and at the bottom part of the studied field. Two transects and five sampling sites along each one were selected. The soil-water retention curves measured on the undisturbed 100-cm3 soil samples taken after the tillage and sowing of winter wheat (October 2010) were highly variable and no differences between sampling sites within the each transect were detected. Variability of soil-water retention curves obtained on soil samples taken after the wheat harvest (August 2011) considerably deceased. The parts of the retention curves, which characterized the soil matrix, were very similar. The main differences between the soil-water retention curves were found in parts, which corresponded to larger capillary pores. The fractions of the large capillary pores (and also saturated soil water-contents) were larger after the harvest (soil structure reestablishment) than that after the tillage and sawing (soil structure disturbance). Greater amount of capillary pores was observed in soils with better developed soil structure documented on the micromorphological images. The saturated hydraulic conductivities (Ks) and unsaturated hydraulic conductivities (K) for the pressure head of -2 cm of topsoil were also measured after the wheat harvest using Guelph permeameter and Minidisk tensiometer, respectively. The highest Ks values were obtained at the steepest parts of the elevation transects, that have been the most eroded. The Ks values at the bottom parts decreased due to the sedimentation processes of eroded soil particles. The change of the

  3. Crop production in salt affected soils: A biological approach

    International Nuclear Information System (INIS)

    Plant are susceptible to deleterious effects of various abiotic and biotic stresses, thus grossly affecting the growth and productivity. Amongst the abiotic stresses, soil salinity is most significant and prevalent in both developed and developing countries. As a consequences, good productive lands are being desertified at a very high pace. To combat this problem various approaches involving soil management and drainage are underway but with little success. It seems that a durable solution of the salinity and water-logging problems may take a long time and we may have to learn to live with salinity and to find other ways to utilize the affected lands fruitfully. A possible approach could be to tailor plants to suit the deleterious environment. The saline-sodic soils have excess of sodium, are impermeable, have little or no organic matter and are biologically almost dead. Introduction of a salt tolerant crop will provide a green cover and will improve the environment for biological activity, increase organic matter and will improve the soil fertility. The plant growth will result in higher carbon dioxide levels, and would thus create acidic conditions in the soil which would dissolve the insoluble calcium carbonate and will help exchange sodium with calcium ions on the soil complex. The biomass produced could be used directly as fodder or by the use of biotechnological and other procedures it could be converted into other value added products. However, in order to tailor plants to suit these deleterious environments, acquisition of better understanding of the biochemical and genetic aspects of salt tolerance at the cellular/molecular level is essential. For this purpose model systems have been carefully selected to carry out fundamental basic research that elucidates and identifies the major factors that confer salt tolerance in a living system. With the development of modern biotechnological methods it is now possible to introduce any foreign genetic material known

  4. Does the different mowing regime affect soil biological activity and floristic composition of thermophilous Pieniny meadow?

    Science.gov (United States)

    Józefowska, Agnieszka; Zaleski, Tomasz; Zarzycki, Jan

    2016-04-01

    The study area was located in the Pieniny National Park in the Carpathian Mountain (Southern Poland). About 30% of Park's area is covered by meadows. The climax stage of this area is forest. Therefore extensive use is indispensable action to keep semi-natural grassland such as termophilous Pieniny meadows, which are characterized by a very high biodiversity. The purpose of this research was to answer the question, how the different way of mowing: traditional scything (H), and mechanical mowing (M) or abandonment of mowing (N) effect on the biological activity of soil. Soil biological activity has been expressed by microbial and soil fauna activity. Microbial activity was described directly by count of microorganisms and indirectly by enzymatic activity (dehydrogenase - DHA) and the microbial biomass carbon content (MBC). Enchytraeidae and Lumbricidae were chosen as representatives of soil fauna. Density and species diversity of this Oligochaeta was determined. Samples were collected twice in June (before mowing) and in September (after mowing). Basic soil properties, such as pH value, organic carbon and nitrogen content, moisture and temperature, were determined. Mean count of vegetative bacteria forms, fungi and Actinobacteria was higher in H than M and N. Amount of bacteria connected with nitrification and denitrification process and Clostridium pasteurianum was the highest in soil where mowing was discontinued 11 years ago. The microbial activity measured indirectly by MBC and DHA indicated that the M had the highest activity. The soil biological activity in second term of sampling had generally higher activity than soil collected in June. That was probably connected with highest organic carbon content in soil resulting from mowing and the end of growing season. Higher earthworm density was in mowing soil (220 and 208 individuals m‑2 in H and M respectively) compare to non-mowing one (77 ind. m‑2). The density of Enchytraeidae was inversely, the higher

  5. Factors causing spatial heterogeneity in soil properties, plant cover, and soil fauna in a non-reclaimed post-mining site

    Czech Academy of Sciences Publication Activity Database

    Frouz, J.; Kalčík, Jiří; Velichová, V.

    2011-01-01

    Roč. 37, č. 11 (2011), s. 1910-1913. ISSN 0925-8574 R&D Projects: GA MŠk 2B08023 Institutional research plan: CEZ:AV0Z60660521 Keywords : soil chemistry * vegetation * invertebrates Subject RIV: EH - Ecology, Behaviour Impact factor: 3.106, year: 2011

  6. Spatial and temporal variability of soil hydraulic properties of topsoil affected by soil erosion

    Science.gov (United States)

    Nikodem, Antonin; Kodesova, Radka; Jaksik, Ondrej; Jirku, Veronika; Klement, Ales; Fer, Miroslav

    2014-05-01

    This study is focused on the comparison of soil hydraulic properties of topsoil that is affected by erosion processes. In order to include variable morphological and soil properties along the slope three sites - Brumovice, Vidim and Sedlčany were selected. Two transects (A, B) and five sampling sites along each one were chosen. Soil samples were taken in Brumovice after the tillage and sowing of winter wheat in October 2010 and after the wheat harvest in August 2011. At locality Vidim and Sedlčany samples were collected in May and August 2012. Soil hydraulic properties were studied in the laboratory on the undisturbed 100-cm3 soil samples placed in Tempe cells using the multi-step outflow test. Soil water retention data points were obtained by calculating water balance in the soil sample at each pressure head step of the experiment. The single-porosity model in HYDRUS-1D was applied to analyze the multi-step outflow and to obtain the parameters of soil hydraulic properties using the numerical inversion. The saturated hydraulic conductivities (Ks) and unsaturated hydraulic conductivities (Kw) for the pressure head of -2 cm of topsoil were also measured after the harvest using Guelph permeameter and Minidisk tensiometer, respectively. In general soil water retention curves measured before and after vegetation period apparently differed, which indicated soil material consolidation and soil-porous system rearrangement. Soil water retention curves obtained on the soil samples and hydraulic conductivities measured in the field reflected the position at the elevation transect and the effect of erosion/accumulation processes on soil structure and consequently on the soil hydraulic properties. The highest Ks values in Brumovice were obtained at the steepest parts of the elevation transects, that have been the most eroded. The Ks values at the bottom parts decreased due to the sedimentation of eroded soil particles. The change of the Kw values along transects didn't show

  7. Soil Properties Affecting the Reductive Capacity of Volcanic Ash Soils in Korea

    Science.gov (United States)

    Chon, C.; Ahn, J.; Kim, K.; Park, K.

    2008-12-01

    Volcanic ash soils or Andisols have distinct chemical and mineralogical properties. The unique chemical properties of Andisols are due to their Al-rich elemental composition, the highly reactive nature of their colloidal fractions, and their large surface area. The soils that developed from volcanic ash on Jeju Island, Korea, were classified as typical Andisols. The soils had an acidic pH, high water content, high organic matter, and clay-silty texture. The crystalline minerals in the samples were mainly ferromagnesian minerals, such as olivine and pyroxene, and iron oxides, such as magnetite and hematite derived from basaltic materials. A large amount of gibbsite was found in the subsurface horizon as a secondary product of the migration of excess Al. In addition, we found that considerable amounts of poorly ordered minerals like allophane and ferrihydrite were present in the Jeju soils. The SiO2 contents were lower than those of other soil orders, while the Al2O3 and Fe2O3 contents were higher. These results reflect some of the important chemical properties of Andisols. The chromium (VI/III) redox couple was used in the reductive capacity measurement. The mean reductive capacity of the Jeju soils was 6.53 mg/L reduced Cr(VI), which is 5.1 times higher than that of non-volcanic ash soils from inland Korea. The reductive capacity of the inland soils was correlated with the total carbon content. Such a high capacity for the reduction of soluble Cr(VI) must also be due to the relatively high carbon contents of the Jeju soils. Nevertheless, despite having 20 times higher total carbon contents, there was no correlation between the reductive capacity of the Jeju soils and the carbon content. These results imply that the reductive capacity of Jeju soils is not only controlled by the carbon content, but is also affected by other soil properties. Correlations of the reductive capacity with major elements showed that Al and Fe were closely connected to the reductive

  8. Saltcedar (Tamarix ramosissima) Invasion Alters Decomposer Fauna and Plant Litter Decomposition in a Temperate Xerophytic Deciduous Forest

    OpenAIRE

    José Camilo Bedano; Laura Sacchi; Evangelina Natale; Herminda Reinoso

    2014-01-01

    Plant invasions may alter the soil system by changing litter quality and quantity, thereby affecting soil community and ecosystem processes. We investigated the effect of Tamarix ramosissima invasion on the decomposer fauna and litter decomposition process, as well as the importance of litter quality in decomposition. Litter decomposition and decomposer communities were evaluated in two monospecific saltcedar forests and two native forests in Argentina, in litterbags containing either local l...

  9. Macrofauna assemblage composition and soil moisture interact to affect soil ecosystem functions

    Science.gov (United States)

    Collison, E. J.; Riutta, T.; Slade, E. M.

    2013-02-01

    Changing climatic conditions and habitat fragmentation are predicted to alter the soil moisture conditions of temperate forests. It is not well understood how the soil macrofauna community will respond to changes in soil moisture, and how changes to species diversity and community composition may affect ecosystem functions, such as litter decomposition and soil fluxes. Moreover, few studies have considered the interactions between the abiotic and biotic factors that regulate soil processes. Here we attempt to disentangle the interactive effects of two of the main factors that regulate soil processes at small scales - moisture and macrofauna assemblage composition. The response of assemblages of three common temperate soil invertebrates (Glomeris marginata Villers, Porcellio scaber Latreille and Philoscia muscorum Scopoli) to two contrasting soil moisture levels was examined in a series of laboratory mesocosm experiments. The contribution of the invertebrates to the leaf litter mass loss of two common temperate tree species of contrasting litter quality (easily decomposing Fraxinus excelsior L. and recalcitrant Quercus robur L.) and to soil CO2 fluxes were measured. Both moisture conditions and litter type influenced the functioning of the invertebrate assemblages, which was greater in high moisture conditions compared with low moisture conditions and on good quality vs. recalcitrant litter. In high moisture conditions, all macrofauna assemblages functioned at equal rates, whereas in low moisture conditions there were pronounced differences in litter mass loss among the assemblages. This indicates that species identity and assemblage composition are more important when moisture is limited. We suggest that complementarity between macrofauna species may mitigate the reduced functioning of some species, highlighting the importance of maintaining macrofauna species richness.

  10. Soil Components Affecting Phosphate Sorption Parameters of Acid Paddy Soils in Guangdong Province

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Soil components affecting phosphate sorption parameters were studied using acid paddy soils derived from basalt, granite, sand-shale and the Pearl River Delta sediments, respectively, in Guangdong Province.For each soil, seven 2.50 g subsamples were equilibrated with 50 mL 0.02 mol L-1 (pH=7.0) of KCl containing 0, 5, 10, 15, 25, 50 and 100 ng P kg-1, respectively, in order to derive P sorption parameters (P sorption maximum, P sorption intensity factor and maximum buffer capacity) by Langmuir isotherm equation. It was shown that the main soil components influencing phosphate sorption maximum (Xm) included soil clay, pH,amorphous iron oxide (Feo) and amorphous aluminum oxide (Alo), with their effects in the order of Alo >Feo > pH > clay. Among these components, pH had a negative effect, and the others had a positive effect.Organic matter (OM) was the only soil component influencing P sorption intensity factor (K). The main components influencing maximum phosphate buffer capacity (MBC) consisted of soil clay, OM, pH, Feo and Alo, with their effects in the order of Alo > OM > pH > Feo > clay. Path analysis indicated that among the components with positive effects on maximum phosphate buffer capacity (MBC), the effect was in the order of Alo > Feo > Clay, while among the components with negative effects, OM > pH. OM played an important role in mobilizing phosphate in acid paddy soils mainly through decreasing the sorption intensity of phosphate by soil particles.

  11. Do Land Characteristics Affect Farmers’ Soil Fertility Management?

    Institute of Scientific and Technical Information of China (English)

    Tan Shu-hao

    2014-01-01

    Soil fertility management (SFM) has important implications for sustaining agricultural development and food self-sufifciency. Better understanding the determinants of farmers’ SFM can be a great help to the adoption of effective SFM practices. Based on a dataset of 315 plots collected from a typical rice growing area of South China, this study applied statistical method and econometric models to examine the impacts of land characteristics on farmers’ SFM practices at plot scale. Main results showed that in general land characteristics affected SFM behaviors. Securer land tenure arrangements facilitated effective practices of SFM through more diversiifed and more soil-friendly cropping pattern choices. Plot size signiifcantly reduced the intensities of phosphorus and potassium fertilizer application. Given other factors, 1 ha increase in plot size might reduce 3.0 kg ha-1 P2O5 and 1.8 kg ha-1 K2O. Plots far from the homestead were paid less attention in terms of both chemical fertilizers and manure applications. Besides, plots with better quality were put more efforts on management by applying more nitrogen and manure, and by planting green manure crops. Signiifcant differences existed in SFM practices between the surveyed villages with different socio-economic conditions. The ifndings are expected to provide important references to the policy-making incentive for improving soil quality and crop productivity.

  12. 内蒙古高原东南缘森林草原交错带土壤动物群落特征%Characteristics of soil fauna community structure in forest-steppe ecotone on Southeastern Inner Mongolia Plateau

    Institute of Scientific and Technical Information of China (English)

    高立杰; 侯建华; 安哲; 高宝嘉

    2013-01-01

    To investigate the characteristics of soil fauna community structure in forest-steppe ecotone on Southeastern Inner Mongolia Plateau,the soil fauna communities from 4 different vegetation zones were investigated.A total of 53 722 soil fauna were collected and classified into 6 phyla,11 classes,and 27 orders,respectively.The dominant groups were Coleoptera,Stylommatophora,Microdrile oligochaetes,Collembola and Hymenoptera among macro-soil-fauna; whereas the dominant groups were Collembola and Acarina among soil meso-and micro-fauna; and the dominant group was Rhabditidia among soil animals of wet type.The individual numbers and the group numbers were declining with the transition from the forest zone to the steppe zone,among which forest zone and forest-meadow area had the highest number of groups as well as the meadowsteppe area in the ecotone and forest zone had the highest number of individuals.Besides,there are differences in numbers and compositions of the dominant groups of soil animal in different vegetation zones and significant difference especially in density-group index (DG),Pielou evenness index (J) and Simpson dominance index (C).The individual numbers and group numbers of soil animals in different vegetation zones showed clear surface assembly.The maximum of the group numbers appeared in summer in all the vegetation zones,but the maximum of the individual numbers in forest-meadow zone and forest zone appeared in autumn.There were not only significant seasonal differences in density-group index in different vegetation zones (except in forest zone) but also differences in the composition and abundance of the dominant groups of soil animals in different seasons.%为了解内蒙古高原东南缘森林草原交错带土壤动物群落特征,对这一地区不同植被地带中的土壤动物进行了调查.共捕获土壤动物53 722只,隶属于6门11纲27目(类).大型土壤动物优势类群为鞘翅目、柄眼目、小蚓类、弹尾目和膜翅目,

  13. Pesticide soil contamination mainly affects earthworm male reproductive parameters

    Institute of Scientific and Technical Information of China (English)

    EduardoBustos-Obregon; RogerIzigaGoicochea

    2002-01-01

    Aim:To explore the effect of exposure to commercial Parathion(Pc)on the reproductive parameters(sperm and cocoon production and genotoxicity on male germ cells),the survival,the body weight and the gross anatomical changes in Eisenia foetida.Methods:Three doses of Pc(1478,739and 444mg/kg of soil)and three thme intervals of exposure(5,15and30days)were used.Results:Alltreated amimals were affected.An acute genotoxic effect,revealed by DNAfragmentation(comet assay),was seen by 5days,Alterations in reproductive parameters were conspicuous in regard to the number of sperm,cocoons and worms born,and the histological observation of the gonads and seminal receptacles.In addition,the body weight and survival rate were decreased,Neuromuscular function was also affected.Conclusion:Earthworms are suitable bioindicators of chemical contamination of the soil,their advantage being their easy and economical handling.

  14. Does the natural "microcosm" created by Tuber aestivum affect soil microarthropods? A new hypothesis based on Collembola in truffle culture

    OpenAIRE

    Menta, Cristina; Garcia Montero, Luis Gonzaga; Pinto, Stefania; Delia Conti, Federica; Baroni, Giampietro; Maresi, Mattia

    2014-01-01

    microarthropods play an important role in fungi dispersion, but little is still known about the interaction between truffle and soil microarthropods. The aim of this study was to investigate the ability of the truffle Tuber aestivum to modify soil biogeochemistry (i.e. create a zone of scarce vegetation around the host plant, called a burn or brûlé) and to highlight the effects of the brûlé on the soil fauna community. We compared soil microarthropod communities found in the soil inside versu...

  15. Soil organic carbon pools and stocks in permafrost-affected soils on the tibetan plateau.

    Directory of Open Access Journals (Sweden)

    Corina Dörfer

    Full Text Available The Tibetan Plateau reacts particularly sensitively to possible effects of climate change. Approximately two thirds of the total area is affected by permafrost. To get a better understanding of the role of permafrost on soil organic carbon pools and stocks, investigations were carried out including both discontinuous (site Huashixia, HUA and continuous permafrost (site Wudaoliang, WUD. Three organic carbon fractions were isolated using density separation combined with ultrasonic dispersion: the light fractions (1.6 g cm(-3 of mineral associated organic matter (MOM. The fractions were analyzed for C, N, and their portion of organic C. FPOM contained an average SOC content of 252 g kg(-1. Higher SOC contents (320 g kg(-1 were found in OPOM while MOM had the lowest SOC contents (29 g kg(-1. Due to their lower density the easily decomposable fractions FPOM and OPOM contribute 27% (HUA and 22% (WUD to the total SOC stocks. In HUA mean SOC stocks (0-30 cm depth account for 10.4 kg m(-2, compared to 3.4 kg m(-2 in WUD. 53% of the SOC is stored in the upper 10 cm in WUD, in HUA only 39%. Highest POM values of 36% occurred in profiles with high soil moisture content. SOC stocks, soil moisture and active layer thickness correlated strongly in discontinuous permafrost while no correlation between SOC stocks and active layer thickness and only a weak relation between soil moisture and SOC stocks could be found in continuous permafrost. Consequently, permafrost-affected soils in discontinuous permafrost environments are susceptible to soil moisture changes due to alterations in quantity and seasonal distribution of precipitation, increasing temperature and therefore evaporation.

  16. Soil organic matter transformation in cryoturbated horizons of permafrost affected soils

    Science.gov (United States)

    Capek, Petr; Diakova, Katerina; Dickopp, Jan-Erik; Barta, Jiri; Santruckova, Hana; Wild, Birgit; Schnecker, Joerg; Guggenberg, Georg; Gentsch, Norman; Hugelius, Gustaf; Kuhry, Peter; Lashchinsky, Nikolaj; Gittel, Antje; Schleper, Christa; Mikutta, Robert; Palmtag, Juri; Shibistova, Olga; Urich, Tim; Zimov, Sergey; Richter, Andreas

    2014-05-01

    Cryoturbated soil horizons are special feature of permafrost affected soils. These soils are known to store great amount of organic carbon and cryoturbation undoubtedly contribute to it to large extent. Despite this fact there is almost no information about soil organic matter (SOM) transformation in cryoturbated horizons. Therefore we carried out long term incubation experiment in which we inspect SOM transformation in cryoturbated as well as in organic and mineral soil horizons under different temperature and redox regimes as potential drivers. We found out that lower SOM transformation in cryoturbated horizons compared to organic horizons was mainly limited by the amount of microbial biomass, which is extremely low in absolute numbers or expressed to SOM concentration. The biochemical transformation ensured by extracellular enzymes is relatively high leading to high concentrations of dissolved organic carbon in cryoturbated horizons. Nevertheless the final step of SOM transformation leading to C mineralization to CO2 or CH4 seems to be restricted by low microbial biomass. Critical step of biochemical transformation of complex SOM is dominated by phenoloxidases, which break down complex organic compounds to simple ones. Their oxygen consumption greatly overwhelms oxygen consumption of the whole microbial community. However the phenoloxidase activity shows strong temperature response with optimum at 13.7° C. Therefore we suggest that apparent SOM stability in cryoturbated horizons, which is expressed in old C14 dated age, is caused by low amount of microbial biomass and restricted diffusion of oxygen to extracellular enzymes in field.

  17. Soil solid materials affect the kinetics of extracellular enzymatic reactions

    Science.gov (United States)

    Lammirato, C.; Miltner, A.; Kästner, M.

    2009-04-01

    INTRODUCTION Soil solid materials affect the degradation processes of many organic compounds by decreasing the bioavailability of substrates and by interacting with degraders. The magnitude of this effect in the environment is shown by the fact that xenobiotics which are readily metabolized in aquatic environments can have long residence times in soil. Extracellular enzymatic hydrolysis of cellobiose (enzyme: beta-glucosidase from Aspergillus niger) was chosen as model degradation process since it is easier to control and more reproducible than a whole cell processes. Furthermore extracellular enzymes play an important role in the environment since they are responsible for the first steps in the degradation of organic macromolecules; beta-glucosidase is key enzyme in the degradation of cellulose and therefore it is fundamental in the carbon cycle and for soil in general. The aims of the project are: 1) quantification of solid material effect on degradation, 2) separation of the effects of minerals on enzyme (adsorption →change in activity) and substrate (adsorption →change in bioavailability). Our hypothesis is that a rate reduction in the enzymatic reaction in the presence of a solid phase results from the sum of decreased bioavailability of the substrate and decreased activity of enzyme molecules. The relative contribution of the two terms to the overall effect can vary widely depending on the chemical nature of the substrate, the properties of the enzyme and on the surface properties of the solid materials. Furthermore we hypothesize that by immobilizing the enzyme in an appropriate carrier the adsorption of enzymes to soil materials can be eliminated and that therefore immobilization can increase the overall reaction rate (activity loss caused by immobilization activity loss caused by adsorption to soil minerals). MATERIALS AND METHODS Enzymatic kinetic experiments are carried out in homogeneous liquid systems and in heterogeneous systems where solid

  18. Soil surface properties affected by organic by-products

    OpenAIRE

    Pachepsky Ya.A.; Rawls W.J.; Fournier L.L.; Filgueira R.R.; Sikora L.J.

    2002-01-01

    The beneficial effects of amending soils with organic by-products include improvement of both chemical and physical factors. Very few studies have investigated changes in the soil specific surface area (SSA) after amendments with manures or composts. Soil samples were taken from plots before and after four years� application of manures, composts or nitrogen fertilizer. A corn-wheat-soybean rotation was grown. Soil samples were tested for changes in water retention at �15 bar, bu...

  19. The Response of Diversity of Soil Fauna Community to Three Cropping Patterns%土壤动物群落多样性对3种种植模式的响应研究

    Institute of Scientific and Technical Information of China (English)

    徐培智; 解开治; 李康活; 陈建生; 唐拴虎; 张发宝; 黄旭

    2012-01-01

    为合理筛选适宜种植模式,维持农业的可持续发展提供参考.采用手捡法和改进的Tullgren干漏斗法,研究休闲轮作(FRCs)、稻菜轮作(RVCs)、蔬菜连作(VCCs)3种种植模式下,土壤动物群落组成及多样性.结果表明,3个处理样点共获得各类土壤动物526只,经鉴定有3门9纲14目.与VCCs、FRCs处理相比,RVCs处理条件下引发了一些类群的发生与消长,造成了部分类群的缺失,形成了不同的优势类群.土壤动物数量0~15 cm土层均多于15~30 cm土层,分别较15~30 cm土层多出15.7%、86.6%和110.0%.RVCs处理Shannon-Weiner指数(月)、Pielou均匀性指数(E)、Simpson优势度指数(C)均为最大,且0~15 cm土层高于15~30 cm土层.土壤动物类群的相似性综合分析表明,VCCs处理与FRCs处理类群的相似性系数较高,与RVCs处理类群的相似性系数较小.%To create a reference by which to select optimal planting patterns, and maintain sustainable development of farmland ecosystems, the hand retrieval and Tullgren dry funnel methods were used to study community composition and diversity of soil fauna in three different cropping patterns; fallow rotation cycles (FRCs), rice-vegetable rotation cycles (RVCs), and vegetable continuous cropping cycles (VCCs). A total of 526 fauna were observed within the three rotation systems, belonging to 9 different phylogenetic classes and 14 different orders. The soil fauna diversity of the VCC, RFC and RVC patterns within the 0-15 cm soil layer averaged respective 15.7%, 86.6% and 110.0% higher than the 15-30 cm soil layer. The Shannon-Wiener index (H), Pielou evenness index (E), and Simpson Dominance index (C) of RVC treatment all reflected highest diversity within the RVC rotation system, as compared to the other two rotation patterns.

  20. Enhancing productivity of salt affected soils through crops and cropping system

    International Nuclear Information System (INIS)

    The reclamation of salt affected soils needs the addition of soil amendment and enough water to leach down the soluble salts. The operations may also include other simple agronomic techniques to reclaim soils and to know the crops and varieties that may be grown and other management practices which may be followed on such soils (Khan, 2001). The choice of crops to be grown during reclamation of salt affected soils is very important to obtain acceptable yields. This also decides cropping systems as well as favorable diversification for early reclamation, desirable yield and to meet the other requirements of farm families. In any salt affected soils, the following three measures are adopted for reclamation and sustaining the higher productivity of reclaimed soils. 1. Suitable choice of crops, forestry and tree species; 2. Suitable choice of cropping and agroforestry system; 3. Other measures to sustain the productivity of reclaimed soils. (author)

  1. The role of snow cover and soil freeze/thaw cycles affecting boreal-arctic soil carbon dynamics

    Directory of Open Access Journals (Sweden)

    Y. Yi

    2015-07-01

    Full Text Available Northern Hemisphere permafrost affected land areas contain about twice as much carbon as the global atmosphere. This vast carbon pool is vulnerable to accelerated losses through mobilization and decomposition under projected global warming. Satellite data records spanning the past 3 decades indicate widespread reductions (∼ 0.8–1.3 days decade−1 in the mean annual snow cover extent and frozen season duration across the pan-Arctic domain, coincident with regional climate warming trends. How the soil carbon pool responds to these changes will have a large impact on regional and global climate. Here, we developed a coupled terrestrial carbon and hydrology model framework with detailed 1-D soil heat transfer representation to investigate the sensitivity of soil organic carbon stocks and soil decomposition to changes in snow cover and soil freeze/thaw processes in the Pan-Arctic region over the past three decades (1982–2010. Our results indicate widespread soil active layer deepening across the pan-Arctic, with a mean decadal trend of 6.6 ± 12.0 (SD cm, corresponding with widespread warming and lengthening non-frozen season. Warming promotes vegetation growth and soil heterotrophic respiration, particularly within surface soil layers (≤ 0.2 m. The model simulations also show that seasonal snow cover has a large impact on soil temperatures, whereby increases in snow cover promote deeper (≥ 0.5 m soil layer warming and soil respiration, while inhibiting soil decomposition from surface (≤ 0.2 m soil layers, especially in colder climate zones (mean annual T ≤ −10 °C. Our results demonstrate the important control of snow cover in affecting northern soil freeze/thaw and soil carbon decomposition processes, and the necessity of considering both warming, and changing precipitation and snow cover regimes in characterizing permafrost soil carbon dynamics.

  2. Atmospheric Deposition of Heavy Metals in Soil Affected by Different Soil Uses of Southern Spain

    Science.gov (United States)

    Acosta, J. A.; Faz, A.; Martínez-Martínez, S.; Bech, J.

    2009-04-01

    Heavy metals are a natural constituent of rocks, sediments and soils. However, the heavy metal content of top soils is also dependent on other sources than weathering of the indigenous minerals; input from atmospheric deposition seems to be an important pathway. Atmospheric deposition is defined as the process by which atmospheric pollutants are transferred to terrestrial and aquatic surfaces and is commonly classified as either dry or wet. The interest in atmospheric deposition has increased over the past decade due to concerns about the effects of deposited materials on the environment. Dry deposition provides a significant mechanism for the removal of particles from the atmosphere and is an important pathway for the loading of heavy metals into the soil ecosystem. Within the last decade, an intensive effort has been made to determine the atmospheric heavy metal deposition in both urban and rural areas. The main objective of this study was to identification of atmospheric heavy metals deposition in soil affected by different soil uses. Study area is located in Murcia Province (southeast of Spain), in the surroundings of Murcia City. The climate is typically semiarid Mediterranean with an annual average temperature of 18°C and precipitation of 350 mm. In order to determine heavy metals atmospheric deposition a sampling at different depths (0-1 cm, 1-5 cm, 5-15 cm and 15-30 cm) was carried out in 7 sites including agricultural soils, two industrial areas and natural sites. The samples were taken to the laboratory where, dried, passed through a 2 mm sieve, and grinded. For the determination of the moisture the samples were weighed and oven dried at 105 °C for 24 h. The total amounts of metals (Pb, Cu, Pb, Zn, Cd, Mn, Ni and Cr) were determined by digesting the samples with nitric/perchoric acids and measuring with ICP-MS. Results showed that zinc contamination in some samples of industrial areas was detected, even this contamination reaches 30 cm depth; thus it is

  3. Cadmium content of plants as affected by soil cadmium concentration

    Energy Technology Data Exchange (ETDEWEB)

    Lehoczky, E. [Pannon Univ. of Agricultural Sciences, Keszthely (Hungary); Szabados, I.; Marth, P. [Plant Health and Soil Conservation Station, Higany (Hungary)

    1996-12-31

    Pot experiments were conducted in greenhouse conditions to study the effects of increasing cadmium (Cd) levels on biomass production and Cd contents in corn, (Zea mays L.), garlic (Allium sativum L.), and spinach (Spinacia oleracea L.). Plants were grown in two soil types: Eutric cambisol soil and A gleyic luvisol soil. Spinach proved to be the most sensitive to Cd treatments as its biomass considerably decreased with the increasing Cd levels. Cadmium contents of the three crops increased with increasing levels of Cd applications. Statistical differences were observed in the Cd contents of crops depending on soil type. With the same Cd rates, Cd tissue concentration of test plants grown in the strongly acidic Gleyic luvisol soil were many times higher than that of plants grown in a neutral Eutric cambisol soil. 14 refs., 4 tabs.

  4. Elucidating key factors affecting radionuclide aging in soils

    International Nuclear Information System (INIS)

    Mechanistic studies allow at present to describe the processes governing the short-term interaction of radiostrontium and radiocaesium in soils. The initial sorption step can be described through the estimation of the soil-soil solution distribution coefficient from soil parameters, as cationic exchange capacity, radiocaesium interception potential and concentration of competing ions in the soil solution. After the initial soil-radionuclide interaction, a fraction of radionuclide is no longer available for exchange with the solution, and it remains fixed in the solid fraction. At present, the initial fixed fraction of a radionuclide in a given soil cannot be predicted from soil properties. Besides, little is known about soil and environmental factors (e.g., temperature; hydric regime) provoking the increase in the fixed fraction with time, the so-called aging process. This process is considered to control the reduction of food contamination with time at contaminated scenarios. Therefore, it is crucial to be able to predict the radionuclide aging in the medium and long term for a better risk assessment, especially when a decision has to be made between relying on natural attenuation versus implementing intervention actions. Here we study radiostrontium and radiocaesium aging in a set of soils, covering a wide range of soil types of contrasting properties (e.g., loamy calcareous; podzol; chernozem, organic). Three factors are separately and simultaneously tested: time elapsed since contamination, temperature and hydric regime. Changes in the radionuclide fixed fraction are estimated with a leaching test based on the use of a mild extractant solution. In addition to this, secondary effects on the radiocaesium interception potential in various soils are also considered. (author)

  5. Fauna Europaea: Gastrotricha

    Science.gov (United States)

    d`Hondt, Jean-Loup; Kisielewski, Jacek; Todaro, M. Antonio; Tongiorgi, Paolo; Guidi, Loretta; Grilli, Paolo

    2015-01-01

    Abstract Fauna Europaea provides a public web-service with an index of scientific names (including important synonyms) of all living European land and freshwater animals, their geographical distribution at country level (up to the Urals, excluding the Caucasus region), and some additional information. The Fauna Europaea project covers about 230,000 taxonomic names, including 130,000 accepted species and 14,000 accepted subspecies, which is much more than the originally projected number of 100,000 species. This represents a huge effort by more than 400 contributing specialists throughout Europe and is a unique (standard) reference suitable for many users in science, government, industry, nature conservation and education. Gastrotricha are a meiobenthic phylum composed of 813 species known so far (2 orders, 17 families) of free-living microinvertebrates commonly present and actively moving on and into sediments of aquatic ecosystems, 339 of which live in fresh and brackish waters. The Fauna Europaea database includes 214 species of Chaetonotida (4 families) plus a single species of Macrodasyida incertae sedis. This paper deals with the 224 European freshwater species known so far, 9 of which, all of Chaetonotida, have been described subsequently and will be included in the next database version. Basic information on their biology and ecology are summarized, and a list of selected, main references is given. As a general conclusion the gastrotrich fauna from Europe is the best known compared with that of other continents, but shows some important gaps of knowledge in Eastern and Southern regions. PMID:26379467

  6. Soil-Structural Stability as Affected by Clay Mineralogy, Soil Texture and Polyacrylamide Application

    Science.gov (United States)

    Soil-structural stability (expressed in terms of aggregate stability and pore size distribution) depends on (i) soil inherent properties, (ii) extrinsic condition prevailing in the soil that may vary temporally and spatially, and (iii) addition of soil amendments. Different soil management practices...

  7. Medicinal Mushroom Growth as Affected by Non-Axenic Casing Soil

    Institute of Scientific and Technical Information of China (English)

    D. C. ZIED; M. T. A. MINHONI; J. KOPYTOWSKI-FILHO; L. BARBOSA; M. C. N. ANDRADE

    2011-01-01

    Ten different casing soils were collected from two soils at two depths (0.2 and 2.0 m below soil surface) to examine the relationships between the physical properties of non-axenic casing soil and yield, number and weight of the medicinal mushroom Agaricus blazei ss. Heinemann. The results showed that soil clay content and bulk density were negatively correlated with the mushroom yield,respectively, but soil silt content and water-holding capacity were found to be positively correlated with the yield. The number of mushrooms was negatively correlated with soil water-holding capacity but positively correlated with soil clay, bulk density and porosity.The weight of mushroom was positively correlated with the content of soil fine sand and negatively correlated with the contents of soil coarse sand, total sand and clay. Neither soil depth nor different soil combinations affected the yield and number of mushrooms, but the mushroom weight was affected by the soil combinations and soil depth, so interplay in the fructification process with the physical characteristics of casing is complicated.

  8. Few apparent short-term effects of elevated soil temperature and increased frequency of summer precipitation on the abundance and taxonomic diversity of desert soil micro- and meso-fauna

    Science.gov (United States)

    Darby, B.J.; Neher, D.A.; Housman, D.C.; Belnap, J.

    2011-01-01

    Frequent hydration and drying of soils in arid systems can accelerate desert carbon and nitrogen mobilization due to respiration, microbial death, and release of intracellular solutes. Because desert microinvertebrates can mediate nutrient cycling, and the autotrophic components of crusts are known to be sensitive to rapid desiccation due to elevated temperatures after wetting events, we studied whether altered soil temperature and frequency of summer precipitation can also affect the composition of food web consumer functional groups. We conducted a two-year field study with experimentally-elevated temperature and frequency of summer precipitation in the Colorado Plateau desert, measuring the change in abundance of nematodes, protozoans, and microarthropods. We hypothesized that microfauna would be more adversely affected by the combination of elevated temperature and frequency of summer precipitation than either effect alone, as found previously for phototrophic crust biota. Microfauna experienced normal seasonal fluctuations in abundance, but the effect of elevated temperature and frequency of summer precipitation was statistically non-significant for most microfaunal groups, except amoebae. The seasonal increase in abundance of amoebae was reduced with combined elevated temperature and increased frequency of summer precipitation compared to either treatment alone, but comparable with control (untreated) plots. Based on our findings, we suggest that desert soil microfauna are relatively more tolerant to increases in ambient temperature and frequency of summer precipitation than the autotrophic components of biological soil crust at the surface.

  9. Cobalt in alluvial Egyptian soils as affected by industrial activities

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Twenty-five surface (0-20 cm) soil samples were collected from different locations in Egypt representing non-polluted,moderately and highly polluted soils. The aim of this study was to evaluate total Co content in alluvial soils of Delta in Egypt using the delayed Neturen activation analysis technique (DNAA). The two prominent gamma ray lines at 1173.2 and 1332.5 keV was efficiently used for 60Co determination. Co content in non-polluted soil samples ranged between 13.12 to 23.20 ppm Co with an average of 18.16*4.38 ppm. Cobalt content in moderately polluted soils ranged between 26.5 to 30.00 ppm with an average of 28.3*1.3 ppm. The highest Co levels (ranged from 36 to 64.69 ppm with an average of 51.9*9.5); were observed in soil samples collected from, either highly polluted agricultural soils due to prolonged irrigation with industrial wastewater or surface soil samples from industrial sites.

  10. PHOSPHORUS FORMS IN CALCAREOUS SOIL AS AFFECTED BY IRRIGATION WATER SALINITY

    OpenAIRE

    ABOU HUSSIEN, E.A.; RADWAN, S.A.; KHALIL, R.A.; HAMAD, M.M.

    2012-01-01

    This study was carried out on five calcareous soils of Egypt characterized by different content (%) of calcium carbonate (CaCO3) and other physical and chemical properties to study their content of different forms of phosphorus and its affected by soil properties and irrigation water salinity. The tested calcareous soils were used in a greenhouse experiment, where these soils were planted by barley and irrigated by tap water and four sources of artificial saline water. The artificial saline ...

  11. Bacteria and protozoa in soil microhabitats as affected by earthworms

    DEFF Research Database (Denmark)

    Winding, Anne; Rønn, Regin; Hendriksen, Niels B.

    1997-01-01

    , were compared. The total, viable, and culturable number of bacteria, the metabolic potentials of bacterial populations, and the number of protozoa and nematodes were determined in soil size fractions. Significant differences between soil fractions were shown by all assays. The highest number of......-cyano-2,3-ditolyl tetrazolim chloride (CTC)-reducing bacteria explained a major part of the variation in the number of protozoa. High protozoan activity and predation thus coincided with high bacterial activity. In soil with elm leaves, fungal growth is assumed to inhibit bacterial and protozoan...... activity. In soil with elm leaves and earthworms, earthworm activity led to increased culturability of bacteria, activity of protozoa, number of nematodes, changed metabolic potentials of the bacteria, and decreased differences in metabolic potentials between bacterial populations in the soil fractions...

  12. Moderately haloalkaliphilic actinomycetes in salt-affected soils

    Science.gov (United States)

    Zvyagintsev, D. G.; Zenova, G. M.; Oborotov, G. V.

    2009-12-01

    It was found that the population density of actinomycetes in solonchaks and saline desert soils varied from hundreds to tens of thousands of colony-forming units (CFUs) per 1 g of soil depending on soil type and was by 1-3 orders of magnitude lower than the number of mycelial bacteria in main soil types. Actinomycetes grow actively in saline soils, and the length of their mycelium reaches 140 m per 1 g of soil. Domination of moderately halophilic, alkaliphilic, and haloalkaliphilic actinomycetes, which grow well under 5% NaCl and pH 8-9, is a specific feature of actinomycetal complexes in saline soils. Representatives of Streptomyces and Micromonospora genera were found among the haloalkaliphilic actinomycetes. Micromonospores demonstrated lower (than streptomycetes) adaptability to high salt concentrations. Investigation of the phylogenetic position of isolated dominant haloalkaliphilic strains of streptomycetes performed on the basis of sequencing of the gene 16S rRNA enabled identifying these strains as Streptomyces pluricolorescens and S. prunicolor.

  13. Bacterial communities in Malagasy soils with differing levels of disturbance affecting botanical diversity.

    Science.gov (United States)

    Blasiak, Leah C; Schmidt, Alex W; Andriamiarinoro, Honoré; Mulaw, Temesgen; Rasolomampianina, Rado; Applequist, Wendy L; Birkinshaw, Chris; Rejo-Fienena, Félicitée; Lowry, Porter P; Schmidt, Thomas M; Hill, Russell T

    2014-01-01

    Madagascar is well-known for the exceptional biodiversity of its macro-flora and fauna, but the biodiversity of Malagasy microbial communities remains relatively unexplored. Understanding patterns of bacterial diversity in soil and their correlations with above-ground botanical diversity could influence conservation planning as well as sampling strategies to maximize access to bacterially derived natural products. We present the first detailed description of Malagasy soil bacterial communities from a targeted 16S rRNA gene survey of greater than 290,000 sequences generated using 454 pyrosequencing. Two sampling plots in each of three forest conservation areas were established to represent different levels of disturbance resulting from human impact through agriculture and selective exploitation of trees, as well as from natural impacts of cyclones. In parallel, we performed an in-depth characterization of the total vascular plant morphospecies richness within each plot. The plots representing different levels of disturbance within each forest did not differ significantly in bacterial diversity or richness. Changes in bacterial community composition were largest between forests rather than between different levels of impact within a forest. The largest difference in bacterial community composition with disturbance was observed at the Vohibe forest conservation area, and this difference was correlated with changes in both vascular plant richness and soil pH. These results provide the first survey of Malagasy soil bacterial diversity and establish a baseline of botanical diversity within important conservation areas. PMID:24465484

  14. Bacterial communities in Malagasy soils with differing levels of disturbance affecting botanical diversity.

    Directory of Open Access Journals (Sweden)

    Leah C Blasiak

    Full Text Available Madagascar is well-known for the exceptional biodiversity of its macro-flora and fauna, but the biodiversity of Malagasy microbial communities remains relatively unexplored. Understanding patterns of bacterial diversity in soil and their correlations with above-ground botanical diversity could influence conservation planning as well as sampling strategies to maximize access to bacterially derived natural products. We present the first detailed description of Malagasy soil bacterial communities from a targeted 16S rRNA gene survey of greater than 290,000 sequences generated using 454 pyrosequencing. Two sampling plots in each of three forest conservation areas were established to represent different levels of disturbance resulting from human impact through agriculture and selective exploitation of trees, as well as from natural impacts of cyclones. In parallel, we performed an in-depth characterization of the total vascular plant morphospecies richness within each plot. The plots representing different levels of disturbance within each forest did not differ significantly in bacterial diversity or richness. Changes in bacterial community composition were largest between forests rather than between different levels of impact within a forest. The largest difference in bacterial community composition with disturbance was observed at the Vohibe forest conservation area, and this difference was correlated with changes in both vascular plant richness and soil pH. These results provide the first survey of Malagasy soil bacterial diversity and establish a baseline of botanical diversity within important conservation areas.

  15. Mycelial actinobacteria in salt-affected soils of arid territories of Ukraine and Russia

    Science.gov (United States)

    Grishko, V. N.; Syshchikova, O. V.; Zenova, G. M.; Kozhevin, P. A.; Dubrova, M. S.; Lubsanova, D. A.; Chernov, I. Yu.

    2015-01-01

    A high population density (up to hundreds of thousands or millions CFU/g soil) of mycelial bacteria (actinomycetes) is determined in salt-affected soils of arid territories of Ukraine, Russia, and Turkmenistan. Of all the studied soils, the lowest amounts of actinomycetes (thousands and tens of thousands CFU/g soil) are isolated from sor (playa) and soda solonchaks developed on the bottoms of drying salt lakes in Buryatia and in the Amu Darya Delta. Actinomycetes of the Streptomyces, Micromonospora, and Nocardiopsis genera were recorded in the studied soils. It is found that conditions of preincubation greatly affect the activity of substrate consumption by the cultures of actinomycetes. This could be attributed to changes in the metabolism of actinomycetes as a mechanism of their adaptation to the increased osmotic pressure of the medium. The alkali tolerance of halotolerant actinomycetes isolated from the salt-affected soils is experimentally proved.

  16. Land use type significantly affects microbial gene transcription in soil.

    Science.gov (United States)

    Nacke, Heiko; Fischer, Christiane; Thürmer, Andrea; Meinicke, Peter; Daniel, Rolf

    2014-05-01

    Soil microorganisms play an essential role in sustaining biogeochemical processes and cycling of nutrients across different land use types. To gain insights into microbial gene transcription in forest and grassland soil, we isolated mRNA from 32 sampling sites. After sequencing of generated complementary DNA (cDNA), a total of 5,824,229 sequences could be further analyzed. We were able to assign nonribosomal cDNA sequences to all three domains of life. A dominance of bacterial sequences, which were affiliated to 25 different phyla, was found. Bacterial groups capable of aromatic compound degradation such as Phenylobacterium and Burkholderia were detected in significantly higher relative abundance in forest soil than in grassland soil. Accordingly, KEGG pathway categories related to degradation of aromatic ring-containing molecules (e.g., benzoate degradation) were identified in high abundance within forest soil-derived metatranscriptomic datasets. The impact of land use type forest on community composition and activity is evidently to a high degree caused by the presence of wood breakdown products. Correspondingly, bacterial groups known to be involved in lignin degradation and containing ligninolytic genes such as Burkholderia, Bradyrhizobium, and Azospirillum exhibited increased transcriptional activity in forest soil. Higher solar radiation in grassland presumably induced increased transcription of photosynthesis-related genes within this land use type. This is in accordance with high abundance of photosynthetic organisms and plant-infecting viruses in grassland. PMID:24553913

  17. Time Lapse Electrical Imaging of Salt Affected Soil and Groundwater

    Science.gov (United States)

    Hayley, Kevin

    This research was conducted to test the hypothesis that time-lapse electrical resistivity imaging (ERI) could be used as an effective tool for monitoring remediation of salt affected soil and groundwater. A time-lapse 3D ERI survey conducted over the span of 3 years was used to observe changes in an oilfield brine plume undergoing remediation using a tile drainage network. A theoretical model was modified to incorporate the results of an electrical conductivity (EC) temperature laboratory experiment and a linear EC temperature relationship was calibrated for the 0--25°C range. Using the linear approximation and theoretical model observed temperature and saturation variations could be accounted for in bulk EC measurements. ERI inversion parameters were selected to produce a model with the best agreement with collocated push tool conductivity logs, and the strongest correlation with core salinity measurements. The ERI models were transformed into salinity estimates in order to produce salt concentration maps and salt removal estimates. A temperature correction method was developed that acted on the collected electrical resistivity data, rather than on the inversion model. A data correction was sought in order to remove the effect of inversion smoothing from the temperature correction and to compensate for temperature prior to inversion opening the possibility of using time-lapse inversion techniques. First the data were inverted to produce a model, and then the model was converted to a standard temperature equivalent model using the previously developed EC temperature relationship. The difference between synthetic datasets produced using the inversion model and the standard temperature equivalent model was used as a data temperature correction factor and applied to the collected data. A simultaneous time-lapse inversion method was developed and compared to previously published methods. The simultaneous approach consisted of inverting the time-lapse datasets together

  18. Soil-aquifer phenomena affecting groundwater under vertisols: a review

    Science.gov (United States)

    Kurtzman, D.; Baram, S.; Dahan, O.

    2016-01-01

    Vertisols are cracking clayey soils that (i) usually form in alluvial lowlands where, normally, groundwater pools into aquifers; (ii) have different types of voids (due to cracking), which make flow and transport of water, solutes and gas complex; and (iii) are regarded as fertile soils in many areas. The combination of these characteristics results in the unique soil-aquifer phenomena that are highlighted and summarized in this review. The review is divided into the following four sections: (1) soil cracks as preferential pathways for water and contaminants: in this section lysimeter-to basin-scale observations that show the significance of cracks as preferential-flow paths in vertisols, which bypass matrix blocks in the unsaturated zone, are summarized. Relatively fresh-water recharge and groundwater contamination from these fluxes and their modeling are reviewed; (2) soil cracks as deep evaporators and unsaturated-zone salinity: deep sediment samples under uncultivated vertisols in semiarid regions reveal a dry (immobile), saline matrix, partly due to enhanced evaporation through soil cracks. Observations of this phenomenon are compiled in this section and the mechanism of evapoconcentration due to air flow in the cracks is discussed; (3) impact of cultivation on flushing of the unsaturated zone and aquifer salinization: the third section examines studies reporting that land-use change of vertisols from native land to cropland promotes greater fluxes through the saline unsaturated-zone matrix, eventually flushing salts to the aquifer. Different degrees of salt flushing are assessed as well as aquifer salinization on different scales, and a comparison is made with aquifers under other soils; (4) relatively little nitrate contamination in aquifers under vertisols: in this section we turn the light on observations showing that aquifers under cultivated vertisols are somewhat resistant to groundwater contamination by nitrate (the major agriculturally related

  19. Monitoring of soil water storage along elevation transech on morphological diverse study-sites affected by soil erosion

    Science.gov (United States)

    Jaksik, Ondrej; Kodesova, Radka; Nikodem, Antonin; Fer, Miroslav; Klement, Ales; Kratina, Josef

    2015-04-01

    Soil water availability is one of the key factors determining plant growth. Spatial distribution of soil water content is influenced by many factors. For the field-scale, one of the most important factors is terrain and its shape. The goal of our study was to characterize soil water storage within the soil profile with respect to terrain attributes. Two morphologically diverse study sites were chosen, in order to monitor soil water storage during vegetation season. The first site Brumovice in located in the Southern Moravian Region. The original soil unit was Haplic Chernozem developed on loess, which was gradually degraded by soil erosion. In the steepest parts, due to substantial loss of soil material, soil is transformed to Regosol. As a result of consequently sedimentation of previously eroded material in toe slopes and terrain depressions colluvial soils are formed. The second site Vidim is placed in the Central Bohemia. Dominant soil unit in wider area is Haplic Luvisol on loess loam. Similar process of progressive soil transformation was identified. On each study site, two elevation transects were delimited, where each consists of 5 monitoring spots. Access tubes were installed in order to measure soil moisture in six different depths (10, 20, 30 40, 60 a 100 cm) using Profile Probe PR2. The monitoring was conducted during vegetation season: April - July 2012 in Brumovice and May - July 2013 in Vidim. The average soil water contents were calculated for following three layers: topsoil A (0-20 cm), subsoil B (20-40cm), and substrate (40-100cm). The soil water storage within the soil profile was also expressed. Sensors TMS3 were also used for continual soil water content monitoring in the depth of 0-15 cm. In addition undisturbed soil samples were taken from topsoil to measure soil hydraulic properties using the multistep outflow experiment. Data were used to assess retention ability of erosion affected soils. The soil water storage and particularly average

  20. Factors affecting the selection of a soil water sensing technology

    International Nuclear Information System (INIS)

    Reviews of soil moisture measurement technologies are counterproductive in attempting to identify the single approach that has the best overall performance for a range of soil, crop and landscape conditions. Not only does such an approach preclude the addition of new technologies, but it also obscures the fact that we have available today sensors and technologies that cover most field conditions, are well understood in terms of technical capability and are mechanically and electronically reliable. This review defines decision-making processes for assessing the characteristics, good and bad, of technology in relation to project objectives. Two processes are needed. The first links soil texture and scale of variability with the nature of the project, single-plant to catchment scale, to the needs for soil water measurement. The second lists the capabilities of some devices and shows how they can be selected to accommodate necessary criteria. It is concluded that the 'best technology' is a function of the project and soil conditions. (author)

  1. Fauna europaea: Diptera - brachycera.

    Science.gov (United States)

    Pape, Thomas; Beuk, Paul; Pont, Adrian Charles; Shatalkin, Anatole I; Ozerov, Andrey L; Woźnica, Andrzej J; Merz, Bernhard; Bystrowski, Cezary; Raper, Chris; Bergström, Christer; Kehlmaier, Christian; Clements, David K; Greathead, David; Kameneva, Elena Petrovna; Nartshuk, Emilia; Petersen, Frederik T; Weber, Gisela; Bächli, Gerhard; Geller-Grimm, Fritz; Van de Weyer, Guy; Tschorsnig, Hans-Peter; de Jong, Herman; van Zuijlen, Jan-Willem; Vaňhara, Jaromír; Roháček, Jindřich; Ziegler, Joachim; Majer, József; Hůrka, Karel; Holston, Kevin; Rognes, Knut; Greve-Jensen, Lita; Munari, Lorenzo; de Meyer, Marc; Pollet, Marc; Speight, Martin C D; Ebejer, Martin John; Martinez, Michel; Carles-Tolrá, Miguel; Földvári, Mihály; Chvála, Milan; Barták, Miroslav; Evenhuis, Neal L; Chandler, Peter J; Cerretti, Pierfilippo; Meier, Rudolf; Rozkosny, Rudolf; Prescher, Sabine; Gaimari, Stephen D; Zatwarnicki, Tadeusz; Zeegers, Theo; Dikow, Torsten; Korneyev, Valery A; Richter, Vera Andreevna; Michelsen, Verner; Tanasijtshuk, Vitali N; Mathis, Wayne N; Hubenov, Zdravko; de Jong, Yde

    2015-01-01

    Fauna Europaea provides a public web-service with an index of scientific names (including important synonyms) of all extant multicellular European terrestrial and freshwater animals and their geographical distribution at the level of countries and major islands (east of the Urals and excluding the Caucasus region). The Fauna Europaea project comprises about 230,000 taxonomic names, including 130,000 accepted species and 14,000 accepted subspecies, which is much more than the originally projected number of 100,000 species. Fauna Europaea represents a huge effort by more than 400 contributing taxonomic specialists throughout Europe and is a unique (standard) reference suitable for many user communities in science, government, industry, nature conservation and education. The Diptera-Brachycera is one of the 58 Fauna Europaea major taxonomic groups, and data have been compiled by a network of 55 specialists. Within the two-winged insects (Diptera), the Brachycera constitute a monophyletic group, which is generally given rank of suborder. The Brachycera may be classified into the probably paraphyletic 'lower brachyceran grade' and the monophyletic Eremoneura. The latter contains the Empidoidea, the Apystomyioidea with a single Nearctic species, and the Cyclorrhapha, which in turn is divided into the paraphyletic 'aschizan grade' and the monophyletic Schizophora. The latter is traditionally divided into the paraphyletic 'acalyptrate grade' and the monophyletic Calyptratae. Our knowledge of the European fauna of Diptera-Brachycera varies tremendously among families, from the reasonably well known hoverflies (Syrphidae) to the extremely poorly known scuttle flies (Phoridae). There has been a steady growth in our knowledge of European Diptera for the last two centuries, with no apparent slow down, but there is a shift towards a larger fraction of the new species being found among the families of the nematoceran grade (lower Diptera), which due to a larger number of small

  2. Different tree species affect soil respiration spatial distribution in a subtropical forest of southern Taiwan

    Science.gov (United States)

    Chiang, Po-Neng; Yu, Jui-Chu; Wang, Ya-nan; Lai, Yen-Jen

    2014-05-01

    Global forests contain 69% of total carbon stored in forest soil and litter. But the carbon storage ability and release rate of warming gases of forest soil also affect global climate change. Soil carbon cycling processes are paid much attention by ecological scientists and policy makers because of the possibility of carbon being stored in soil via land use management. Soil respiration contributed large part of terrestrial carbon flux, but the relationship of soil respiration and climate change was still obscurity. Most of soil respiration researches focus on template and tropical area, little was known that in subtropical area. Afforestation is one of solutions to mitigate CO2 increase and to sequestrate CO2 in tree and soil. Therefore, the objective of this study is to clarify the relationship of tree species and soil respiration distribution in subtropical broad-leaves plantation in southern Taiwan. The research site located on southern Taiwan was sugarcane farm before 2002. The sugarcane was removed and fourteen broadleaved tree species were planted in 2002-2005. Sixteen plots (250m*250m) were set on 1 km2 area, each plot contained 4 subplots (170m2). The forest biomass (i.e. tree height, DBH) understory biomass, litter, and soil C were measured and analyzed at 2011 to 2012. Soil respiration measurement was sampled in each subplot in each month. The soil belongs to Entisol with over 60% of sandstone. The soil pH is 5.5 with low base cations because of high sand percentage. Soil carbon storage showed significantly negative relationship with soil bulk density (p<0.001) in research site. The differences of distribution of live tree C pool among 16 plots were affected by growth characteristic of tree species. Data showed that the accumulation amount of litterfall was highest in December to February and lowest in June. Different tree species planted in 16 plots, resulting in high spatial variation of litterfall amount. It also affected total amount of litterfall

  3. Pyrosequencing-based assessment of bacterial community structure in mine soils affected by mining subsidence

    Institute of Scientific and Technical Information of China (English)

    Li Yuanyuan a; Chen Longqian a; ⇑; Wen Hongyu b; Zhou Tianjian a; Zhang Ting a

    2014-01-01

    Based on the 454 pyrosequencing approach, this research evaluated the influence of coal mining subsi-dence on soil bacterial diversity and community structure in Chinese mining area. In order to characterize the bacterial community comparatively, this study selected a field experiment site with coal-excavated subsidence soils and an adjacent site with non-disturbed agricultural soils, respectively. The dataset com-prises 24512 sequences that are affiliated to the 7 phylogenetic groups: proteobacteria, actinobacteria, bacteroidetes, gemmatimonadetes, chloroflexi, nitrospirae and unclassified phylum. Proteobacteria is the largest bacterial phylum in all samples, with a marked shift of the proportions of alpha-, beta-, and gammaproteobacteria. The results show that undisturbed soils are relatively more diverse and rich than subsided soils, and differences in abundances of dominant taxonomic groups between the two soil groups are visible. Compared with the control, soil nutrient contents decline achieves significant level in subsided soils. Correlational analysis showed bacterial diversity indices have significantly positive corre-lation with soil organic matter, total N, total P, and available K, but in negative relation with soil salinity. Ground subsidence noticeably affects the diversity and composition of soil microbial community. Degen-eration of soil fertility and soil salinization inhibits the sole-carbon-source metabolic ability of microbial community, leading to the simplification of advantage species and uneven distribution of microbial spe-cies. This work demonstrates the great potential of pyrosequencing technique in revealing microbial diversity and presents background information of microbial communities of mine subsidence land.

  4. Physical mechanisms of plant roots affecting weathering and leaching of loess soil

    Institute of Scientific and Technical Information of China (English)

    LI; Yong; ZHANG; Qingwen; WAN; Guojiang; HUANG; Ronggui; PIAO; Hechun; BAI; Lingyu; LI; Lu

    2006-01-01

    Plant roots have potential impacts on soil mineral weathering and leaching. Our objective is to understand the physical mechanisms of plant roots affecting weathering and leaching of loess soil. Root densities were measured through the method of a large-size dug profile, and transport fluxes of soil elements were determined using an undisturbed monolith soil infiltration device on the hilly and gully regions of the Chinese Loess Plateau. The results show that the improvement effects of soil environment by plant roots are mainly controlled by the density and weight of the fibrous roots with the diameters less than 1 mm. Plant roots have the stronger effects on soil physical properties than chemical properties. The principal components analysis (PCA) indicates that soil physical properties by plant roots account for 56.7% of variations in soil environment whereas soil chemical properties and pH contribute about 24.2% of the soil variations. The roles of plant roots in controlling soil weathering and leaching increased in the following order: infiltration enhancement > increase of bioactive substance > stabilization of soil structure. The effects of plant roots on soil mineral weathering and leaching can be quantified using the multiple regression models with the high prediction accuracies developed in this study.

  5. Self diffusion coefficient of phosphorus in different soils of Egypt as affected by soil moisture and phosphate fertilizer

    International Nuclear Information System (INIS)

    The effect of soil water content and phosphate fertilization vz. phosphate diffusion on plant growth and p-uptake was studied by use of tracer technique. Two experiments were conducted using three different Egyptian soils, i.e. clay from Bahtim, loamy from Burg El-Arab and sandy loam from Abou-Zaabal. The first was a laboratory experiment and aimed to determine the self diffusion coefficient of 32P, sup(D)P, in these different soils, as affected by soil moisture content and phosphate fertilization. The second was a pot experiment conducted to further investigate the uptake and dry matter yield of corn plants under the same conditions mentioned in the first experiment. The data revealed that as the P applied was raised from 0 to 100 Kgp/Fed, the values of sup(D)P were increased with different magnitude according to the soil texture and its moisture content. The highest values for the sup(D)P were of the clay soil of Bahtim, while the lowest were of the sandy loam soil of Abou-Zaabal. The data showed the positive trends towards increasing the sup(D)P values with increasing soil moisture contents. The study of pot experiment showed that plant uptake of P is closely related to the diffusion coefficient of P in soils. The practical implication of the present study indicates that more phosphorus needs to be applied to crops during periods of moisture stress than during periods of adequate soil moisture level to provide optimum phosphorus nutrition to plants. The clay soils should show less tendency toward P deficiency during dry conditions than would sandy soils having less clay. Similarly, irrigation should help to overcome P-deficiencies, particularly on light-textured soils. (author)

  6. Influences affecting the soil-water characteristic curve

    Institute of Scientific and Technical Information of China (English)

    ZHOU Jian; YU Jian-lin

    2005-01-01

    The soil-water characteristic curve (SWCC) is the primary partially saturated soil information as its behavior and properties can be derived from it. Although there have been many studies of unsaturated soils and the SWCC, there is still no combined constitutive model that can simulate soil characteristics accurately. In cases when hydraulic hysteresis is dominant (e.g.under cyclic loading) it is particularly important to use the SWCC. In the past decades, several mathematical expressions have been proposed to model the curve. There are various influences on the SWCC as a source of information, so the curves obtained from conventional tests often cannot be directly applied;and the mathematical expressions from one scenario cannot be used to simulate another situation. The effects of void ratio, initial water content, stress state and high suction were studied in this work revealing that water content and stress state are more important than the other effects;but that the influences tend to decrease when suction increases. The van Genuchten model was modified to simulate better the changes in the degree of saturation at low values of suction. Predictions were compared with experimental results to determine the simulation capability of the model.

  7. Low-Temperature Biochar Affects an Eroded Calcareous Soil

    Science.gov (United States)

    Previous research showed little benefit from using a high temperature, high pH biochar for improving the fertility of eroded calcareous soils. We thus explored the potential of an activated, low-temperature, low pH biochar to improve their fertility status. In a microcosm study conducted at 20 de...

  8. Factors that affect the association of radionuclides with soil phases

    International Nuclear Information System (INIS)

    The use of field experiments to investigate the chemical or physical associations of some radionuclides with soil phases is limited by low levels of activity and complicated by the number of phases involved. Sequential extraction procedures provide one means of evaluating the relative importance of various phases in disposition. Although the separation steps may not be absolutely selective, these schemes can be used in a comparative manner to rationalise changes in association and disposition that can occur as soil conditions alter. In this way they can give a direction for specific laboratory studies and be of value in the prediction of the consequences of land contamination - an important aspect of radiological protection. In this paper the authors draw upon field and laboratory studies of the disposition of artificial radionuclides to illustrate the effects of changes in, for example, iron or organic content. The variety of soil types that are amenable to field studies is restricted. Complementary laboratory experiments are therefore essential. Results show that the generalisations often applied to radionuclide availability are not always approximate and that although predictions of disposition can sometimes be made on the basis of gross soil characteristics, this capability is limited and a more rigorous approach is desirable in extreme cases. The specificity of the extraction procedure is discussed and evidence is presented to support the participation of the residual phase which was previously observed in field studies of plutonium and americium

  9. Effect of brushwood transposition on the leaf litter arthropod fauna in a cerrado area

    Directory of Open Access Journals (Sweden)

    Paula Cristina Benetton Vergílio

    2013-10-01

    Full Text Available The results of ecological restoration techniques can be monitored through biological indicators of soil quality such as the leaf litter arthropod fauna. This study aimed to determine the immediate effect of brushwood transposition transferred from an area of native vegetation to a disturbed area, on the leaf litter arthropod fauna in a degraded cerrado area. The arthropod fauna of four areas was compared: a degraded area with signal grass, two experimental brushwood transposition areas, with and without castor oil plants, and an area of native cerrado. In total, 7,660 individuals belonging to 23 taxa were sampled. Acari and Collembola were the most abundant taxa in all studied areas, followed by Coleoptera, Diptera, Hemiptera, Hymenoptera, and Symphyla. The brushwood transposition area without castor oil plants had the lowest abundance and dominance and the highest diversity of all areas, providing evidence of changes in the soil community. Conversely, the results showed that the presence of castor oil plants hampered early succession, negatively affecting ecological restoration in this area.

  10. Sorption of tannin-C by soils affects soil cation exchange capacity

    Science.gov (United States)

    Some tannins, produced by plants, are able to sorb to soil, and thus influence soil organic matter and nutrient cycling. However, studies are needed that compare sorption of tannins to other related phenolic compounds, evaluate their effects across a broad range of soils, and determine if sorption ...

  11. Soil nematodes (Nematoda) in the Voděradské bučiny National Nature Reserve, Czech Republic - an overall characterisation of the fauna

    Czech Academy of Sciences Publication Activity Database

    Háněl, Ladislav

    České Budějovice : Institute of Soil Biology, BC ASCR, 2013. s. 26. ISBN 978-80-86525-23-5. [Central European Workshop on Soil Zoology /12./. 08.04.2013-11.04.2013, České Budějovice] R&D Projects: GA ČR(CZ) GA206/93/0276 Institutional support: RVO:60077344 Keywords : soil nematodes * Voděradské bučiny National Nature Reserve Subject RIV: EH - Ecology, Behaviour

  12. Root activity, some crops as affected by soil strength

    International Nuclear Information System (INIS)

    To find out the relationship between soil strength and root activity of different crops, the experiment was conducted on Haryana Agricultural University Farm, Hissar. Open drums were placed one foot deep. 5 cm thick densities 1.4 (Control), 1.6 and 1.8 g/cc were placed at 25 cm depth in various drums. Test crops taken were pea, gram, wheat and barley. Bulk density of higher order in combination with low moisture levels resulted in more detrimental effects on root penetration of the crop in general but at some stages significant interaction between bulk density and moisture was observed where low moisture favoured the root entry through the compacted layers of soil. (author)

  13. Soil Diversity as Affected by Land Use in China: Consequences for Soil Protection

    Directory of Open Access Journals (Sweden)

    Wei Shangguan

    2014-01-01

    Full Text Available Rapid land-use change in recent decades in China and its impact on terrestrial biodiversity have been widely studied, particularly at local and regional scales. However, the effect of land-use change on the diversity of soils that support the terrestrial biological system has rarely been studied. Here, we report the first effort to assess the impact of land-use change on soil diversity for the entire nation of China. Soil diversity and land-use effects were analyzed spatially in grids and provinces. The land-use effects on different soils were uneven. Anthropogenic soils occupied approximately 12% of the total soil area, which had already replaced the original natural soils. About 7.5% of the natural soil classes in China were in danger of substantial loss, due to the disturbance of agriculture and construction. More than 80% of the endangered soils were unprotected due to the overlook of soil diversity. The protection of soil diversity should be integrated into future conservation activities.

  14. Structure of domination of fauna in soil of central flood plain of the Samara river in the conditions of experimental heavy metal pollution

    Directory of Open Access Journals (Sweden)

    O. М. Kunah

    2005-09-01

    Full Text Available The analysisresults of the soil animal complexes structure under in situ experimental heavy metal contamination are presented. The heavy metalsaffect the soil community over a year by changing the dominant structure of animal complexes. The main trend of changing dominant structure of the abundance and biomass is the decrease of absolute dominant and unimportantspecies role and the increase of the role of secondary species and dominants.

  15. Factors Affecting Anion Movement and Retention in Four Forest Soils

    OpenAIRE

    D. W. Johnson; Cole, D. W.; Van Miegroet, Helga; Horng, F. W.

    1986-01-01

    Three hypotheses concerning the movement and retention of anions in forest soils were tested in a series of laboratory and field studies on two Tennessee Ultisols with mixed deciduous forest cover and two Washington Inceptisols, one with deciduous (red alder Alnus rubra Bong.) and one with coniferous [Douglas-fir, Pseudotsuga menziesii (Mirb.) Franco] forest cover. The first hypothesis, that sulfate and phosphate retention was related to adsorption to free Fe and Al oxides, which were in turn...

  16. Urban legacies and soil management affect the concentration and speciation of trace metals in Los Angeles community garden soils

    International Nuclear Information System (INIS)

    Heavy metals in urban soils can compromise human health, especially in urban gardens, where gardeners may ingest contaminated dust or crops. To identify patterns of urban garden metal contamination, we measured concentrations and bioavailability of Pb, As, and Cd in soils associated with twelve community gardens in Los Angeles County, CA. This included sequential extractions to partition metals among exchangeable, reducible, organic, or residual fractions. Proximity to road increased all metal concentrations, suggesting vehicle emissions sources. Reducible Pb increased with neighborhood age, suggesting leaded paint as a likely pollutant source. Exchangeable Cd and As both increased with road proximity. Only cultivated soils showed an increase in exchangeable As with road proximity, potentially due to reducing humic acid interactions while Cd bioavailability was mitigated by organic matter. Understanding the geochemical phases and metal bioavailability allows incorporation of contamination patterns into urban planning. - Highlights: • Road proximity, legacies, and management affect garden soil metal concentrations. • Soil near old houses had high reducible Pb, likely due to lead paint. • Pb, As, and Cd all increased with proximity to road. • As and Cd reacted with organic matter to become more or less bioavailable to crops. - Road proximity, legacies, and management affect garden soil metal concentrations. Soil near old houses had high reducible Pb due to lead paint, while all metals increased near the road

  17. Fauna venenosa mundial

    OpenAIRE

    Fernández Rubio, Fidel; Moreno Fernández-Caparrós, Luis; Soriano, Óscar

    2015-01-01

    La proyección de las Fuerzas Armadas a otros escenarios fuera del territorio nacional hace necesario disponer de actualizada información sobre las especies venenosas. Siendo la biogeografía médica uno de los epígrafes a tener presente en los documentos de inteligencia sanitaria, la publicación recoge y describe los hábitos de toda la fauna venenosa terrestre y acuática; indica sus características morfológicas para identificar las especies venenosas mortales; señala las regiones donde se asie...

  18. Hydraulic properties of typical salt-affected soils in Jiangsu Province,China

    Institute of Scientific and Technical Information of China (English)

    CHEN Xiaomin; SHEN Qirong; XU Yangchun

    2007-01-01

    Every year about 1,500 ha of land is reclaimed from the sea along the coastline of Jiangsu Province,China.It is important to characterize the hydraulic properties of this reclaimed land to be able to predict and manage salt and water movement for amelioration of these saline soils.In this paper,we report hydraulic properties of these salt-affected soils.The pressure-plate method,constant head method,the crust method and Klute's method were used in this study.The satu rated hydraulic conductivities of the soils ranged from 128.66 to 141.26 cm/day and decreased with increasing soil depth.The unsaturated hydraulic conductivities followed an expo nential function of pressure head.The soil water retention curves were similar for three soil layers in the soil.The satu rated water content,field capacity and wilting point decreased with increasing soil depth.Plant available water contents of the three layers in the soil profile were 0.21,0.20 and 0.19 cm3/cm3,respectively.The unsaturated soil water diffu sivity of the studied soils ranged from 0.07 to 10.46 cm2/min,and was related to the water content via an exponential relationship.

  19. Soil-restoration rate and initial soil formation trends on example of anthropogenically affected soils of opencast mine in Kursk region, Russian Federation

    Science.gov (United States)

    Pigareva, Tatiana

    2015-04-01

    The mining industry is one of the main factors which anthropogenically change the environment. Mining process results in removing of the rocks and mechanical changes of considerable amounts of ground. One of the main results of mining arising of antropic ecosystems as well as increasing of the new created soils total area is technosols. The main factor controlling the soil formation in postmining environment is the quality of spoiled materials. Initial soil formation has been investigated on spoils of the largest iron ore extraction complex in Russia - Mikhailovsky mining and concentration complex which is situated in Kursk region, Russia. Investigated soils are presented by monogenetic weak developed soils of different age (10-15-20 years). Young soils are formed on the loess parent materials (20 year-old soil), or on a mix of sand and clay overburdens (15 and 10-year-old soils). Anthropogenically affected soils are characterized by well-developed humus horizon which is gradually replaced by weakly changed soil-building rocks (profile type A-C for 10-, 15-years old soils, and A-AC-C for 20 years old soils). Gray-humus soils are characterized by presence of diagnostic humus horizon gradually replaced by soil-building rock. The maximum intensity of humus accumulation has been determined in a semi-hydromorphic 10-year-old soil developed on the mixed heaps which is connected with features of water-air conditions complicating mineralization of plant remnants. 20-year-old soil on loess is characterized by rather high rate of organic substances accumulation between all the automorphous soils. It was shown that one of the most effective restoration ways for anthropogenically affected soils is a biological reclamation. Since overburdens once appeared on a day surface are overgrown badly in the first years, they are subject to influence of water and wind erosion. Our researchers have found out that permanent grasses are able to grow quickly; they accumulate a considerable

  20. Minimum quantity of urban refuse compost affecting physical and chemical soil properties

    Directory of Open Access Journals (Sweden)

    Andrea Rocchini

    2011-02-01

    Full Text Available The increasing production of urban waste requires urgent responses because of various environmental problems that arise when urban refuse is stored in landfills or incinerated. Recycling of domestic waste and composting of its organic fraction has been indicated as a possible disposal solution. A three-year experiment was conducted to quantify the minimum rate of urban refuse compost (URC addition able to improve some physical and chemical soil properties at the lowest cost and environmental impact. URC was added to a silty clay soil and to a sandy loam soil 0%, 3%, 6%, 9% rate (w/w. Samplings were made 12, 24 and 36 months after URC application. To study the only effect of compost on soil due to its interaction with the soil matrix, each soil-compost mixture was divided into three boxes and kept outdoors weed free. After 12 months, 3% URC resulted the minimum quantity able to ameliorate several soil properties. In silty clay soil this rate significantly ameliorated microaggregate stability and hydraulic conductivity, but negative effects were observed on electrical conductivity. After 24 months, 3% rate significantly increased soil organic matter content. In the sandy loam soil, after 12 months, 3% rate of URC determined a positive effect on organic matter and cone resistance in dry soil condition. Electrical conductivity increased at 3% URC addition. The minimum URC quantity affecting hydraulic conductivity and plastic limit was 6%, and 9% for the liquid limit. Under these experimental conditions, the lowest rate (3% of URC incorporation to soils appears to be the minimum quantity able to improve most of the soil properties influencing fertility. What the results show is that, to achieve sustainability of urban refuse compost application to agricultural soil, further research is needed to investigate soil property changes in the range between 0% and 3%.

  1. Minimum quantity of urban refuse compost affecting physical and chemical soil properties

    Directory of Open Access Journals (Sweden)

    Paolo Bazzoffi

    Full Text Available The increasing production of urban waste requires urgent responses because of various environmental problems that arise when urban refuse is stored in landfills or incinerated. Recycling of domestic waste and composting of its organic fraction has been indicated as a possible disposal solution. A three-year experiment was conducted to quantify the minimum rate of urban refuse compost (URC addition able to improve some physical and chemical soil properties at the lowest cost and environmental impact. URC was added to a silty clay soil and to a sandy loam soil 0%, 3%, 6%, 9% rate (w/w. Samplings were made 12, 24 and 36 months after URC application. To study the only effect of compost on soil due to its interaction with the soil matrix, each soil-compost mixture was divided into three boxes and kept outdoors weed free. After 12 months, 3% URC resulted the minimum quantity able to ameliorate several soil properties. In silty clay soil this rate significantly ameliorated microaggregate stability and hydraulic conductivity, but negative effects were observed on electrical conductivity. After 24 months, 3% rate significantly increased soil organic matter content. In the sandy loam soil, after 12 months, 3% rate of URC determined a positive effect on organic matter and cone resistance in dry soil condition. Electrical conductivity increased at 3% URC addition. The minimum URC quantity affecting hydraulic conductivity and plastic limit was 6%, and 9% for the liquid limit. Under these experimental conditions, the lowest rate (3% of URC incorporation to soils appears to be the minimum quantity able to improve most of the soil properties influencing fertility. What the results show is that, to achieve sustainability of urban refuse compost application to agricultural soil, further research is needed to investigate soil property changes in the range between 0% and 3%.

  2. Sorption interactions of organic compounds with soils affected by agricultural olive mill wastewater.

    Science.gov (United States)

    Keren, Yonatan; Borisover, Mikhail; Bukhanovsky, Nadezhda

    2015-11-01

    The organic compound-soil interactions may be strongly influenced by changes in soil organic matter (OM) which affects the environmental fate of multiple organic pollutants. The soil OM changes may be caused by land disposal of various OM-containing wastes. One unique type of OM-rich waste is olive mill-related wastewater (OMW) characterized by high levels of OM, the presence of fatty aliphatics and polyphenolic aromatics. The systematic data on effects of the land-applied OMW on organic compound-soil interactions is lacking. Therefore, aqueous sorption of simazine and diuron, two herbicides, was examined in batch experiments onto three soils, including untreated and OMW-affected samples. Typically, the organic compound-soil interactions increased following the prior land application of OMW. This increase is associated with the changes in sorption mechanisms and cannot be attributed solely to the increase in soil organic carbon content. A novel observation is that the OMW application changes the soil-sorbent matrix in such a way that the solute uptake may become cooperative or the existing ability of a soil sorbent to cooperatively sorb organic molecules from water may become characterized by a larger affinity. The remarkable finding of this study was that in some cases a cooperative uptake of organic molecules by soils makes itself evident in distinct sigmoidal sorption isotherms rarely observed in soil sorption of non-ionized organic compounds; the cooperative herbicide-soil interactions may be characterized by the Hill model coefficients. However, no single trend was found for the effect of applied OMW on the mechanisms of organic compound-soil interactions. PMID:26183941

  3. Effectiveness of Organic Wastes as Fertilizers and Amendments in Salt-Affected Soils

    Directory of Open Access Journals (Sweden)

    Mariangela Diacono

    2015-04-01

    Full Text Available Excessive salt rate can adversely influence the physical, chemical, and biological properties of soils, mainly in arid and semi-arid world regions. Therefore, salt-affected soils must be reclaimed to maintain satisfactory fertility levels for increasing food production. Different approaches have been suggested to solve these issues. This short review focuses on selected studies that have identified organic materials (e.g., farmyard manures, different agro-industrial by-products, and composts as effective tools to improve different soil properties (e.g., structural stability and permeability in salt-affected soils. Organic fertilization is highly sustainable when compared to other options to date when taken into consideration as a solution to the highlighted issues. However, further experimental investigations are needed to validate this approach in a wider range of both saline and sodic soils, also combining waste recycling with other sustainable agronomic practices (crop rotations, cover crops use, etc..

  4. Biochar pyrolyzed at two temperatures affects Escherichia coli transport through a sandy soil.

    Science.gov (United States)

    Bolster, Carl H; Abit, Sergio M

    2012-01-01

    The incorporation of biochar into soils has been proposed as a means to sequester carbon from the atmosphere. An added environmental benefit is that biochar has also been shown to increase soil retention of nutrients, heavy metals, and pesticides. The goal of this study was to evaluate whether biochar amendments affect the transport of Escherichia coli through a water-saturated soil. We looked at the transport of three E. coli isolates through 10-cm columns packed with a fine sandy soil amended with 2 or 10% (w/w) poultry litter biochar pyrolyzed at 350 or 700°C. For all three isolates, mixing the high-temperature biochar at a rate of 2% into the soil had no impact on transport behavior. When added at a rate of 10%, a reduction of five orders of magnitude in the amount of E. coli transported through the soil was observed for two of the isolates, and a 60% reduction was observed for the third isolate. Mixing the low-temperature biochar into the soil resulted in enhanced transport through the soil for two of the isolates, whereas no significant differences in transport behavior were observed between the low-temperature and high-temperature biochar amendments for one isolate. Our results show that the addition of biochar can affect the retention and transport behavior of E. coli and that biochar application rate, biochar pyrolysis temperature, and bacterial surface characteristics were important factors determining the transport of E. coli through our test soil. PMID:22218181

  5. Soil acidity as affecting micronutrients concentration, nitrato reductase enzyme activity and yield in upland rice plants

    Directory of Open Access Journals (Sweden)

    Edemar Moro

    2013-12-01

    Full Text Available The lowest grain yield of rice under no-tillage system (NTS in relation to the conventional system may be due to the predominance nitrate in the soil and the low nitrate reductase activity. Another reason may be caused by micronutrient deficiency because of superficially soil acidity corrections. Therefore, the objective of this study was to evaluate the changes caused by soil pH in the N forms in the soil, micronutrients concentration in rice plants, nitrate reductase activity, yield of rice and its components. The experiment was performed in a greenhouse conditions. The experimental design was a completely randomized in a factorial three (levels of soil acidity x five (micronutrients sources with four replications. The addition of micronutrients does not affect levels of nitrate and ammonium in the soil; soil acidity significantly affects levels of nitrate and ammonium in the soil, concentration of micronutrients in rice plants and crop yield and its components; medium soil acidity (pH 5.5 result in medium to high levels of Cu and Fe, medium level of Zn and Mn, high nitrate reductase activity, resulting in higher dry matter, tillers, panicles, spikelets, weight of 100 grains and hence grain yield.

  6. Thallium occurrence and partitioning in soils and sediments affected by mining activities in Madrid province (Spain)

    Energy Technology Data Exchange (ETDEWEB)

    Gomez-Gonzalez, M.A.; Garcia-Guinea, J. [National Museum of Natural Sciences, CSIC, Jose Gutierrez Abascal 2, 28006 Madrid (Spain); Laborda, F. [Group of Analytical Spectroscopy and Sensors Group, Institute of Environmental Sciences, University of Zaragoza, Pedro Cerbuna 12, 50009 Zaragoza (Spain); Garrido, F., E-mail: fernando.garrido@mncn.csic.es [National Museum of Natural Sciences, CSIC, Jose Gutierrez Abascal 2, 28006 Madrid (Spain)

    2015-12-01

    Thallium (Tl) and its compounds are toxic to biota even at low concentrations but little is known about Tl concentration and speciation in soils. An understanding of the source, mobility, and dispersion of Tl is necessary to evaluate the environmental impact of Tl pollution cases. In this paper, we examine the Tl source and dispersion in two areas affected by abandoned mine facilities whose residues remain dumped on-site affecting to soils and sediments of natural water courses near Madrid city (Spain). Total Tl contents and partitioning in soil solid phases as determined by means of a sequential extraction procedure were also examined in soils along the riverbeds of an ephemeral and a permanent streams collecting water runoff and drainage from the mines wastes. Lastly, electronic microscopy and cathodoluminescence probe are used as a suitable technique for Tl elemental detection on thallium-bearing phases. Tl was found mainly bound to quartz and alumino-phyllosilicates in both rocks and examined soils. Besides, Tl was also frequently found associated to organic particles and diatom frustules in all samples from both mine scenarios. These biogenic silicates may regulate the transfer of Tl into the soil-water system. - Highlights: • Abandoned mine residues are Tl sources in soils of Madrid catchment area. • Tl was associated to quartz and aluminosilicates in both rocks and soils. • Tl was frequently found associated to organic particles and diatom frustules. • Cathodoluminescence is a suitable technique for Tl detection on soils and rocks.

  7. Thallium occurrence and partitioning in soils and sediments affected by mining activities in Madrid province (Spain)

    International Nuclear Information System (INIS)

    Thallium (Tl) and its compounds are toxic to biota even at low concentrations but little is known about Tl concentration and speciation in soils. An understanding of the source, mobility, and dispersion of Tl is necessary to evaluate the environmental impact of Tl pollution cases. In this paper, we examine the Tl source and dispersion in two areas affected by abandoned mine facilities whose residues remain dumped on-site affecting to soils and sediments of natural water courses near Madrid city (Spain). Total Tl contents and partitioning in soil solid phases as determined by means of a sequential extraction procedure were also examined in soils along the riverbeds of an ephemeral and a permanent streams collecting water runoff and drainage from the mines wastes. Lastly, electronic microscopy and cathodoluminescence probe are used as a suitable technique for Tl elemental detection on thallium-bearing phases. Tl was found mainly bound to quartz and alumino-phyllosilicates in both rocks and examined soils. Besides, Tl was also frequently found associated to organic particles and diatom frustules in all samples from both mine scenarios. These biogenic silicates may regulate the transfer of Tl into the soil-water system. - Highlights: • Abandoned mine residues are Tl sources in soils of Madrid catchment area. • Tl was associated to quartz and aluminosilicates in both rocks and soils. • Tl was frequently found associated to organic particles and diatom frustules. • Cathodoluminescence is a suitable technique for Tl detection on soils and rocks

  8. Biochemical resistance of pyrogenic organic matter in fire-affected mineral soils of Southern Europe

    Science.gov (United States)

    Knicker, H.; González Vila, F. J.; Clemente Salas, L.

    2012-04-01

    Incorporated into the soil, naturally formed pyrogenic organic matter (PyOM) is considered as highly recalcitrant, but direct estimation of PyOM decomposition rates are scarce. With this aim in mind, we subjected organic matter (OM) of fire-affected and unaffected soils to biochemical degradation under laboratory conditions and monitored CO2 production over a period of seven months. The soils derived from fire affected and unaffected areas of the Sierra de Aznalcóllar and the Doñana National Park, Southern Spain. Virtual fractionation of the solid-state 13C nuclear magnetic resonance (NMR) spectra of the fire affected soils into fire-unaffected soil organic matter (SOM) and PyOM yielded charcoal C contributions of 30 to 50% to the total organic C (Corg) of the sample derived from the Aznalcóllar region. Fitting the respiration data with a double exponential decay model revealed a fast carbon flush during the first three weeks of the experiment. Solid-state 13C NMR spectroscopy evidenced the contribution of aromatic moieties of the PyOM to this initial carbon release and to the biosynthesis of new microbial biomass. The input of PyOM resulted in an increase of the mean residence time (MRT) of the slow OM pool of the soil by a factor of 3 to 4 to approximately 40 years which rises doubts rises doubts about the presumed big influence of PyOM as an additional C-sink in soils. On the other hand, although being small the difference in turnover rates is evident and has some major implication with respect to long-term alteration of the chemical composition of OM in fire-affected soils. Based on the obtained results and the analysis of PyOM in other soil systems, a conceptual model is presented which can explain the different behavior of PyOM under different soil conditions.

  9. Decreasing seagrass density negatively influences associated fauna

    OpenAIRE

    Rosemary M McCloskey; Unsworth, Richard K. F.

    2015-01-01

    Seagrass meadows globally are disappearing at a rapid rate with physical disturbances being one of the major drivers of this habitat loss. Disturbance of seagrass can lead to fragmentation, a reduction in shoot density, canopy height and coverage, and potentially permanent loss of habitat. Despite being such a widespread issue, knowledge of how such small scale change affects the spatial distribution and abundances of motile fauna remains limited. The present study investigated fish and macro...

  10. Effects of rock fragments on water dynamics in a fire-affected soil

    Science.gov (United States)

    Gordillo-Rivero, Ángel J.; García-Moreno, Jorge; Jordán, Antonio; Zavala, Lorena M.

    2014-05-01

    Rock fragments (RF) are common in the surface of Mediterranean semiarid soils, and have important effects on the soil physical (bulk density and porosity) and hydrological processes (infiltration, evaporation, splash erosion and runoff generation) (Poesen and Lavee, 1994; Rieke-Zapp et al., 2007). In some cases, RFs in Mediterranean areas have been shown to protect bare soils from erosion risk (Cerdà, 2001; Martínez-Zavala, Jordán, 2008; Zavala et al., 2010). Some of these effects are much more relevant when vegetation cover is low or has been reduced after land use change or other causes, as forest fires. Although very few studies exist, the interest on the hydrological effects of RFs in burned areas is increasing recently. After a forest fire, RFs may contribute significantly to soil recovery. In this research we have studied the effect of surface and embedded RFs on soil water control, infiltration and evaporation in calcareous fire-affected soils from a Mediterranean area (SW Spain). For this study, we selected an area with soils derived from limestone under holm oak forest, recently affected by a moderate severity forest fire. The proportion of RF cover showed a significant positive relation with soil water-holding capacity and infiltration rates, although infiltration rate reduced significantly when RF cover increased above a certain threshold. Soil evaporation rate decreased with increasing volumetric content of RFs and became stable with RF contents approximately above 30%. Evaporation also decreased with increasing RF cover. When RF cover increased above 50%, no significant differences were observed between burned and control vegetated plots. REFERENCES Poesen, J., Lavee, H. 1994. Rock fragments in top soils: significance and processes. Catena Supplement 23, 1-28. Cerdà, A. 2001. Effect of rock fragment cover on soil infiltration, interrill runoff and erosion. European Journal of Soil Science 52, 59-68. DOI: 10.1046/j.1365-2389.2001.00354.x. Rieke

  11. Mineralization and carbon turnover in subarctic heath soil as affected by warming and additional litter

    DEFF Research Database (Denmark)

    Rinnan, Riikka; Michelsen, Anders; Baath, Erland;

    2007-01-01

    carbon turnover (measured as changes in the pools during a growing-season-long field incubation of soil cores in situ). The mainly N limited bacterial communities had shifted slightly towards limitation by C and P in response to seven growing seasons of warming. This and the significantly increased...... bacterial growth rate under warming may partly explain the observed higher C loss from the warmed soil. This is furthermore consistent with the less dramatic increase in the contents of dissolved organic carbon (DOC) and dissolved organic N (DON) in the warmed soil than in the soil from ambient temperature...... during the field incubation. The added litter did not affect the carbon content, but it was a source of nutrients to the soil, and it also tended to increase bacterial growth rate and net mineralization of P. The inorganic N pool decreased during the field incubation of soil cores, especially in the...

  12. Antimony mobility in Japanese agricultural soils and the factors affecting antimony sorption behavior

    International Nuclear Information System (INIS)

    The mobility of antimony (Sb) in Japanese agricultural soils was studied by radiotracer experiments using 124Sb tracer. The soil-solution distribution coefficients (K d) of Sb were measured for 110 soil samples. These K ds ranged from 1 to 2065 L kg-1; the geometric mean was 62 L kg-1 excluding one extremely high value, 2065 L kg-1. Experimental measurement of K d showed a decrease with both increasing pH and increasing phosphate concentration. The latter suggested that one aspect of the Sb sorption phenomena in Japanese soil was influenced by specific adsorption of anions such as phosphate. However, other aspects could not be explained by this specific adsorption mechanism, because only 20-40% of soil-sorbed Sb could be extracted by phosphate solution. - Antimony mobility in tested Japanese agricultural soils was generally low and was affected by pH and phosphate concentration

  13. Fractionation of Uranium Forms as Affected by Spiked Soil Treatment and Soil Type

    International Nuclear Information System (INIS)

    In a fractionation experiment Uranium forms were compared in two soil types (Mostorud and Elgabalelasfar soil). Also, the variation of U forms due to soil treatment (spiking) were studied. In case of Mostorud soil the initial U - fractions were 45.63 % as residual form, 20.69 % organically bound 16.36 % Mn and Fe oxides bound, 9.76% Carbonate form, 7.41 % exchangeable fractions and 0.15% water soluble fractions. These fractions varied significantly when the soil was spiked with 200 mg U/Kg soil to 46.88 %, 23.19 %, 9.97 %, 16.07 %, 3.79% and 0.10% for residual, organically, Mn- Fe oxide, carbonate, exchangeable and water soluble fractions respectively. These result showed significant reduction in U-ex fraction forms and Mn- Fe bound forms with significant increase in U- carbonate form due to U application. In case of Elgabalelasfar soil, the main U - fractions were 57.42% as residual form (relatively higher residual - U form in the clayey soil) 16.10 % organically bound, 13.78% Mn and Fe oxides bound, 7.22 % Carbonate form, 5.23 % exchangeable fractions and 0.25 % water soluble fractions The application of 200 mg U/Kg soil resulted in a significant changes in U - Fractions distribution as follows : 59.26 % , 11.27 % , 19.59 % , 6.84 % , 2.90 % and 0.14 % for residual , organic , Mn- Fe oxides , carbonate, exchangeable and water soluble fractions , respectively.

  14. Comparison of Soil Fauna (Oribatids and Enchytraeids)Between Conventional and Organic (Tillage and No—Tillage Practices)Farming Crop Fields in Japan

    Institute of Scientific and Technical Information of China (English)

    M.FUJITA; S.FUJIYAMA

    2001-01-01

    The major soil animal groups,enchyraeid worms and oribatid mites,were compared in the abundance and diversity between conventional fields(CT)and organic farming fields with tillage(OT) or no-tillage(ON)practices,The values of abundance,species richness,diversity and evenness were significantly larger in OT and ON than in CT,indicating that the abundance and diversity in organic farming fields were greater than those in conventional farming,The community structure of enchytraeid genera was different between OT and ON,Enchytraeus was the most abundant in OT ,while Fridericia in ON,The abundance of oribatids in OT was similar th that in ON,while the species richness and diversity in the former were smaller,These results suggeste that no-tilage practice under organic management might comtribute to the improvement in quality of soil mesofauna.

  15. Soil Diversity as Affected by Land Use in China: Consequences for Soil Protection

    OpenAIRE

    Wei Shangguan; Peng Gong; Lu Liang; YongJiu Dai; Keli Zhang

    2014-01-01

    Rapid land-use change in recent decades in China and its impact on terrestrial biodiversity have been widely studied, particularly at local and regional scales. However, the effect of land-use change on the diversity of soils that support the terrestrial biological system has rarely been studied. Here, we report the first effort to assess the impact of land-use change on soil diversity for the entire nation of China. Soil diversity and land-use effects were analyzed spatially in grids and pro...

  16. Key biogeochemical factors affecting soil carbon storage in Posidonia meadows

    Science.gov (United States)

    Serrano, Oscar; Ricart, Aurora M.; Lavery, Paul S.; Mateo, Miguel Angel; Arias-Ortiz, Ariane; Masque, Pere; Rozaimi, Mohammad; Steven, Andy; Duarte, Carlos M.

    2016-08-01

    Biotic and abiotic factors influence the accumulation of organic carbon (Corg) in seagrass ecosystems. We surveyed Posidonia sinuosa meadows growing in different water depths to assess the variability in the sources, stocks and accumulation rates of Corg. We show that over the last 500 years, P. sinuosa meadows closer to the upper limit of distribution (at 2-4 m depth) accumulated 3- to 4-fold higher Corg stocks (averaging 6.3 kg Corg m-2) at 3- to 4-fold higher rates (12.8 g Corg m-2 yr-1) compared to meadows closer to the deep limits of distribution (at 6-8 m depth; 1.8 kg Corg m-2 and 3.6 g Corg m-2 yr-1). In shallower meadows, Corg stocks were mostly derived from seagrass detritus (88 % in average) compared to meadows closer to the deep limit of distribution (45 % on average). In addition, soil accumulation rates and fine-grained sediment content (factors within the meadow. We conclude that there is a need to improve global estimates of seagrass carbon storage accounting for biogeochemical factors driving variability within habitats.

  17. Organic Matter Decomposition in Red Soil as Affected by Earthworms

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The earthworms Pheretima carnosa, Drawida gisti and Eisenia foetida were studied to compare their contributions to the decomposition of various organic materials surface-applied on red soil in a 165-day greenhouse experiment. The native species Pheretima carnosa and Drawida gisti were equally effective in accelerating the decomposition of maize residue, according to fresh body weight, while commercial species Eisenia foetida had no significant influence on dry mass loss of maize residue. Liming with CaCO3 or CaO showed little effect on maize residue breakdown involved by Pheretima carnosa, but it inhibited this process involved by Drawida gisti. The capability of Pheretima carnosa to the decomposition of five kinds of organic materials was thoroughly examined. The dry mass losses in worm treatments were in the order of soybean residue > maize residue > pig manure > semi-decayed maize > ryegrass. However, the relative contributions of the earthworm to dry mass loss were in the order of pig manure (89.8%) > semi-decayed maize residue (49.1%) > maize residue (29.4%) > soybean residue (20.9%) > ryegrass residue (16.5%). Pheretima carnosa consumed 20~120 mg dry weight of organic material per gram fresh weight of biomass per day.

  18. Effects of Olive Mill Wastewater on Soil Microarthropods and Soil Chemistry in Two Different Cultivation Scenarios in Israel and Palestinian Territories

    OpenAIRE

    Markus Peter Kurtz; Benjamin Peikert; Carsten Brühl; Arnon Dag; Isaac Zipori; Jawad Hasan Shoqeir; Gabriele Ellen Schaumann

    2015-01-01

    Although olive mill wastewater (OMW) is often applied onto soil and is known to be phytotoxic, its impact on soil fauna is still unknown. The objective of this study was to investigate how OMW spreading in olive orchards affects Oribatida and Collembola communities, physicochemical soil properties and their interdependency. For this, we treated plots in two study sites (Gilat, Bait Reema) with OMW. Among others, the sites differed in irrigation practice, soil type and climate. We observed tha...

  19. Characterizing Soil Organic Matter Degradation Levels in Permafrost-affected Soils using Infrared Spectroscopy

    Science.gov (United States)

    Matamala, R.; Jastrow, J. D.; Calderon, F.; Liang, C.; Miller, R. M.; Ping, C. L.; Michaelson, G. J.; Hofmann, S.

    2014-12-01

    Diffuse-reflectance Fourier-transform mid-infrared spectroscopy (MidIR) was used to (1) investigate soil quality along a latitudinal gradient of Alaskan soils, and in combination with soil incubations, (2) to assess the relative lability of soil organic matter in the active layer and upper permafrost for some of those soils. Twenty nine sites were sampled along a latitudinal gradient (78.79 N to 55.35 N deg). The sites included 8 different vegetation types (moss/lichen, non-acidic and acidic tundra, shrub areas, deciduous forests, mixed forests, coniferous forests, and grassland). At each site, soils were separated by soil horizons and analyzed for pH, cation exchange capacity (CEC), organic and inorganic C, and total N. Samples were also scanned to obtain MidIR spectra, and ratios of characteristic bands previously suggested as indicators of organic matter quality or degradation level were calculated. Principal component analysis showed that axis 1 explained 70% of the variation and was correlated with the general Organic:Mineral ratio, soil organic C, total N, and CEC, but not with vegetation type. Axis 2 explained 25% of the variation and was correlated with most of the band ratios, with negative values for the condensation index (ratio of aromatic to aliphatic organic matter) and positive values for all humification ratios (HU1: ratio of aliphatic to polysaccharides; HU2: ratio of aromatics to polysaccharides; and HU3 ratio of lignin/phenols to polysaccharides) suggesting that axis 2 variations were related to differences in level of soil organic matter degradation. Active organic, active mineral and permafrost layers from selected tundra sites were incubated for two months at -1, 1, 4, 8 and 16 ⁰C. The same band ratios were correlated with total CO2 mineralized during the incubations. Data from 4⁰C showed that the cumulative respired CO2 from the active organic layer across all sites was negatively correlated with the HU1 humification ratio, suggesting

  20. Effectiveness of Organic Wastes as Fertilizers and Amendments in Salt-Affected Soils

    OpenAIRE

    Mariangela Diacono; Francesco Montemurro

    2015-01-01

    Excessive salt rate can adversely influence the physical, chemical, and biological properties of soils, mainly in arid and semi-arid world regions. Therefore, salt-affected soils must be reclaimed to maintain satisfactory fertility levels for increasing food production. Different approaches have been suggested to solve these issues. This short review focuses on selected studies that have identified organic materials (e.g., farmyard manures, different agro-industrial by-products, and composts)...

  1. Imaging Spectroscopy of salt-affected soils: Model-based integrated method

    OpenAIRE

    Farifteh, Jamshid

    2007-01-01

    In the literature, a compound process (a series of processes, together) termed as salinization/alkalinization, is referred to as the most frequently occurring land degradation type in semi and arid regions. These processes are the product of a complex interaction of various factors, which cause changes within a time period of about a decade, generally irreversible, resulting in increase of salt in soils. Excessive salts precipitation in soil profile develops to the formation of salt-affected ...

  2. Investigation of Factors Affecting Cracking Behavior in Paddy Soils (Case study: Guilan province)

    OpenAIRE

    M. R. Yazdani; M. Parsinejad; A.R Sepaskhah; Davatgar, N.; S. Araghinejad

    2015-01-01

    Intermittent irrigation of paddy fields with long intervals can cause cracks in heavy soils, facilitate loss of water and finally damage the crop. This study was carried out in order to investigate the cracking trend and some other factors affecting soil cracking in four different physiographical areas of paddy field. The study areas were Rasht, Shanderman, Astaneh and Khomam in Guilan province. The experiment was carried out in paddy fields with transplanted rice by determining the physical ...

  3. Assessing Soil Quality in Areas Affected by Sulfide Mining. Application to Soils in the Iberian Pyrite Belt (SW Spain

    Directory of Open Access Journals (Sweden)

    Isabel González

    2011-11-01

    Full Text Available The characterization, evaluation and remediation of polluted soils is one of the present environmental challenges to be addressed in the coming years. The origin of trace elements in soils can be either geogenic or anthropogenic, but only the latter is interesting from a legal point of view. The hazard of the pollutants in the soils not only depends on their total concentration, but particularly on their availability. The mobility of the trace elements depends on their speciation, and it is also affected by several soil parameters. Mining activity is one of the most important anthropogenic causes of soil pollution. As a case study, this work is focused in the Riotinto mining area (Iberian Pyrite Belt, IPB, SW Spain. The IPB is one of the most important metallogenic provinces in the world and it has been exploited for thousands of years. The disposal of mining residues has produced important sources of contamination by trace elements and acidic waters affecting soils and rivers. In addition to these problems, the closure of mines in the Pyrite Belt at the end of the 20th Century has led to a great loss of employment, which has caused the development of an intensive agriculture of citrus fruits as a new source of income. The intensive growing of citrus fruits and the traditional subsistence agriculture have been developed surrounding the mining areas and on floodplains near to mining sites. The level of soil pollution has not been taken into account in these cases, nor has its impact on the health of the inhabitants of these areas. Therefore, it is of great interest to study the current state of the cultivated soils and the sources and types of contaminants derived from mining activity in order to program its decontamination, where appropriate, according to legislation. In order to know the present and future hazard posed by the soils chemical and mineralogical speciation has been carried out, given that the availability of a metal depends on the

  4. [Sizes of soil macropores and related main affecting factors on a vegetated basalt slope].

    Science.gov (United States)

    Guan, Qi; Xu, Ze-Min; Tian, Lin

    2013-10-01

    The landslide on vegetated slopes caused by extreme weather has being increased steadily, and the preferential flow in soil macropores plays an important role in the landslide. By using water breakthrough curve and Poiseuille equation, this paper estimated the radius range, amount, and average volume of soil macropores on a vegetated basalt slope of Maka Mountain, Southwest China, and analyzed the distribution of the soil macropores and the main affecting factors. In the study area, the radius of soil macropores ranged from 0.3 to 1.8 mm, mainly between 0.5 and 1.2 mm. The large-radius macropores (1.4-1.8 mm) were lesser, while the small-radius macropores (soil profile, soil macropores were more in upper layers and lesser in deeper layers. The average volume of the macropores contributed 84.7% to the variance of steady effluent rate. Among the factors affecting the average volume of the large macropores, vegetations root mass had a linear relationship, with the correlation coefficient being 0.70, and soil organic matter content also had a linear relationship, with the correlation coefficient being 0.64. PMID:24483084

  5. Půdní fauna - modelové skupiny

    Czech Academy of Sciences Publication Activity Database

    Pižl, Václav; Rusek, Josef; Starý, Josef; Tajovský, Karel

    České Budějovice : Jihočeská univerzita v Českých Budějovicích, 2004, s. 177-183. ISBN 80-7040-756-5 Institutional research plan: CEZ:AV0Z6066911 Keywords : soil fauna * model groups Subject RIV: EH - Ecology, Behaviour

  6. Soil pollution state as affected by different soil fertility regulation measures

    International Nuclear Information System (INIS)

    The content of 14 chemical elements was measured in the soil of ten long-term field trials located in different climatic zones of Lithuania. Soil samples were taken from the control (untreated) and anthropogenic (fertilized with mineral NPK and/or organic fertilizers, limed) treatment plots. The samples were analyzed by the AAS method and directly analyzed with X-rays upon fine grinding (for Sr). In the western zone of Lithuania the anthropogenic impact (liming with fertilizing) resulted in statistically significant increase in the content of 4 elements (B, Ni, Sr, Zn). In the eastern zone 3 elements (Cu, Co, Sr) showed significant differences. Soil contamination index was exceeded significantly (up to 2 versus the background levels) only for Sr (2.14 times) in the western zone

  7. Co-contaminants and factors affecting the sorption behaviour of two sulfonamides in pasture soils

    International Nuclear Information System (INIS)

    We investigated the effect of soil pH, organic carbon, ionic strength and steroid hormones on the sorption of sulfamethoxazole (SMO) and sulfachloropyridazine (SCP) in three pastoral soils of New Zealand. A model linking sorbate speciation with species-specific sorption coefficients describing the pH dependence of the apparent sorption coefficients was used to derive the fraction of each species of SMO. All soils displayed a decrease in sorption when pH was increased, with SMO exhibiting the highest sorption at pH 2. The cationic form of SMO appeared to sorb more close to pH ≥ pKa1 and, when pH ≥ pKa2 (6.5, 7.5 and 8.5) the anionic species seems to dominate, however, its sorption affinity to all soils was low. SMO sorption was affected by ionic strengths and organic carbon content, while the presence of hormones showed only a subtle decrease in SCP sorption in a selected model pasture soil. -- Highlights: •The effect of OC content on sulfamethoxazole sorption is nullified by the pH effect. •Steroid hormone has a subtle influence on the sulfachloropyridazine sorption in pastoral soil. •Increased hormone concentrations decrease sulfachloropyridazine sorption in soils. -- Sorption affinity of SMO and SCP are strongly governed by multitude of factors, and variations in these factors can be significant when manure and fertilisers are added to soil

  8. Spatial variability of soil nitrogen in a hilly valley: Multiscale patterns and affecting factors.

    Science.gov (United States)

    Zhang, Shirong; Xia, Chunlan; Li, Ting; Wu, Chungui; Deng, Ouping; Zhong, Qinmei; Xu, Xiaoxun; Li, Yun; Jia, Yongxia

    2016-09-01

    Estimating the spatial distribution of soil nitrogen at different scales is crucial for improving soil nitrogen use efficiency and controlling nitrogen pollution. We evaluated the spatial variability of soil total nitrogen (TN) and available nitrogen (AN) in the Fujiang River Valley, a typical hilly region composed of low, medium and high hills in the central Sichuan Basin, China. We considered the two N forms at single hill, landscape and valley scales using a combined method of classical statistics, geostatistics and a geographic information system. The spatial patterns and grading areas of soil TN and AN were different among hill types and different scales. The percentages of higher grades of the two nitrogen forms decreased from low, medium to high hills. Hill type was a major factor determining the spatial variability of the two nitrogen forms across multiple scales in the valley. The main effects of general linear models indicated that the key affecting factors of soil TN and AN were hill type and fertilization at the single hill scale, hill type and soil type at the landscape scale, and hill type, slope position, parent material, soil type, land use and fertilization at the valley scale. Thus, the effects of these key factors on the two soil nitrogen forms became more significant with upscaling. PMID:27135562

  9. Comparison of Soil Fauna (Oribatids and Enchytraeids){1mm BetweenConventional and Organic (Tillage and No-1mm TillagePractices) Farming Crop Fields in Japan

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The major soil animal groups, enchytraeid worms and oribatid mites,were compared in the abundance and diversity between conventionalfields (CT) and organic farming fields with tillage (OT) or no-tillage(ON) practices. The values of abundance, species richness, diversityand evenness were significantly larger in OT and ON than in CT,indicating that the abundance and diversity in organic farming fieldswere greater than those in conventional farming. The communitystructure of enchytraeid genera was different between OT and ON.{ Enchytraeus was the most abundant in OT, whileFridericia in ON. The abundance of oribatids in OT was similarto that in ON, while the species richness and diversity in the formerwere smaller. These results suggested that no-tillage practice underorganic management might contribute to the improvement in quality ofsoil mesofauna.

  10. Growth and phosphorus uptake of sorghum plants in salt affected soil as affected by organic materials composted with rock phosphate

    International Nuclear Information System (INIS)

    A field experiment was conducted to determine the influence of different organic materials, Farm yard manure (FYM), Humic acid (HA) and Press mud (PM) and their composts prepared with rock phosphate on the growth and phosphorus (P) uptake of sorghum (Sorghum bicolor L.). The experiment was conducted in Randomized Complete Block design with three replication in salt affected soil at research farm of botanical garden Azakhel Nowshera during kharif 2012. Fertilizers were applied at the rate of 120- 90-60 kg ha/sup -1/ N, P and K, respectively. The source of N was urea and organic materials in composted and non composted form. Single super phosphate, rock phosphate, organic materials and their composts were used as P source, while sulphate of potash was used as source of K. The organic materials were applied before crop sowing at recommended level on the basis of their P content. The maximum and significantly (p=0.05) increased sorghum total dry matter yield of 23733 kg ha/sup -1/, emergence m/sup -2/ of 142 and plant height of 147 cm were observed in the treatment where composts of FYM, HA and PM were applied in combination. Increase in soil organic matter content was recorded by the application of composts of different organic materials, while decreasing trend was found in the values of soil electrical conductivity (ECe) and sodium adsorption ratio (SAR). Maximum plant N uptake of 159 kg ha/sup -1/, P uptake of 62.5 kg ha/sup -1/ and K uptake of 557 kg ha/sup -1/ were noted in the treatment where a combination of composts of FYM, HA and PM were added. Results suggest that the use of composts of different organic materials and RP are environment friendly and have the potential to improve sorghum growth, plants nutrient uptake and ameliorate salt affected soils. (author)

  11. Soil hydraulic properties of topsoil along two elevation transects affected by soil erosion

    Czech Academy of Sciences Publication Activity Database

    Nikodem, A.; Kodešová, R.; Jakšík, O.; Jirků, V.; Fér, M.; Klement, A.; Žigová, Anna

    2013-01-01

    Roč. 15, - (2013). ISSN 1607-7962. [EGU General Assembly /10./. 07.04.2013-12.04.2013, Vienna] Institutional support: RVO:67985831 Keywords : topsoil * hydraulic properties * erosion processes Subject RIV: DF - Soil Science http://meetingorganizer.copernicus.org/EGU2013/EGU2013-7924.pdf

  12. Emission and distribution of fumigants as affected by soil moistures in three different textured soils

    Science.gov (United States)

    Stringent environmental regulations are being developed to control the emission of soil fumigants to reduce air pollution. Water application is a low-cost strategy for fumigant emission control and applicable for a wide range of commodity groups, especially those with low profit margins. Although it...

  13. Fauna Europaea: Helminths (Animal Parasitic)

    Czech Academy of Sciences Publication Activity Database

    Gibson, D. I.; Bray, R. A.; Hunt, D.; Georgiev, B. B.; Scholz, Tomáš; Harris, P.D.; Bakke, T.A.; Pomajska, T.; Niewiadomska, K.; Kostadinova, Aneta; Tkach, V.; Bain, O.; Durette-Desset, M.-C.; Gibbons, L.; Moravec, František; Petter, A.; Dimitrova, Z.M.; Buchmann, K.; Valtonen, E. T.; de Jong, Y.

    -, č. 2 (2014), e1060. ISSN 1314-2828 Institutional support: RVO:60077344 Keywords : Acanthocephala * Biodiversity * Biodiversity Informatics * Cestoda * Fauna Europaea * Helminth * Monogenea * Nematoda * Parasite * Taxonomic indexing * Taxonomy * Trematoda * Zoology Subject RIV: EB - Genetics ; Molecular Biology

  14. Golf courses and wetland fauna

    OpenAIRE

    Colding, Johan; Lundberg, Jakob; Lundberg, Stefan; Andersson, Erik

    2009-01-01

    Golf courses are often considered to be chemical-intensive ecosystems with negative impacts on fauna. Here we provide evidence that golf courses can contribute to the support and conservation of wetland fauna, i.e., amphibians and macroinvertebrates. Comparisons of amphibian occurrence, diversity of macroinvetebrates, and occurrence of species of conservation concern were made between permanent freshwater ponds surveyed on golf courses around Sweden's capital city, Stockholm, and off-course p...

  15. Synchrotron microtomographic quantification of geometrical soil pore characteristics affected by compaction

    Science.gov (United States)

    Udawatta, Ranjith P.; Gantzer, Clark J.; Anderson, Stephen H.; Assouline, Shmuel

    2016-05-01

    Soil compaction degrades soil structure and affects water, heat, and gas exchange as well as root penetration and crop production. The objective of this study was to use X-ray computed microtomography (CMT) techniques to compare differences in geometrical soil pore parameters as influenced by compaction of two different aggregate size classes. Sieved (diameter soil cores of 5 by 5 mm (average porosities were 0.44 and 0.35) were imaged at 9.6 μm resolution at the Argonne Advanced Photon Source (synchrotron facility) using X-ray CMT. Images of 58.9 mm3 volume were analyzed using 3-Dimensional Medial Axis (3-DMA) software. Geometrical characteristics of the spatial distributions of pore structures (pore radii, volume, connectivity, path length, and tortuosity) were numerically investigated. Results show that the coordination number (CN) distribution and path length (PL) measured from the medial axis were reasonably fit by exponential relationships P(CN) = 10-CN/Co and P(PL) = 10-PL/PLo, respectively, where Co and PLo are the corresponding characteristic constants. Compaction reduced porosity, average pore size, number of pores, and characteristic constants. The average pore radii (63.7 and 61 µm; p density than the high-density treatment. Aggregate size also influenced measured geometrical pore parameters. This analytical technique provides a tool for assessing changes in soil pores that affect hydraulic properties and thereby provides information to assist in assessment of soil management systems.

  16. Yield and Nicotine Content of Flue-Cured Tobacco as Affected by Soil Nitrogen Mineralization

    Institute of Scientific and Technical Information of China (English)

    JU Xiao-Tang; CHAO Feng-Chun; LI Chun-Jian; JIANG Rong-Feng; P.CHRISTIE; ZHANG Fu-Suo

    2008-01-01

    Nitrogen (N) supply is the most important factor affecting yield and quality of flue-cured tobacco (FCT).A field experiment and an in situ incubation method were used to study the effects of soil N mineralization in the later stages of growth on yield and nicotine content of FCT in Fenggang and Jiusha,Guizhou Province.The yield and market value of FCT at Fenggang were much lower than those at Jinsha.However,the nicotine content of middle and upper leaves was much higher at Fenggang than at Jiusha when the same rate of fertilizer N was applied,which might be due to a higher N supply capacity at the Fenggang site.At later stages of growth (7-16 weeks after transplanting),the soil net N mineralization at Fenggang (56 kg N ha-1) was almost double that at Jiusha (30 kg N ha-1).While soil NHa-N and NO3-N were almost exhausted by the plants or leached 5 weeks after transplanting,the N taken up at the later growth stages at Fenggang were mainly derived from soil N mineralization,which contributed to a high nicotine content in the upper leaves.The order of soil N contribution to N buildup in different leaves was:upper leaves > middle leaves > lower leaves.Thus,soil N mineralization at late growth stages was an important factor affecting N accumulation and therefore the nicotine content in the upper leaves.

  17. Thallium occurrence and partitioning in soils and sediments affected by mining activities in Madrid province (Spain).

    Science.gov (United States)

    Gomez-Gonzalez, M A; Garcia-Guinea, J; Laborda, F; Garrido, F

    2015-12-01

    Thallium (Tl) and its compounds are toxic to biota even at low concentrations but little is known about Tl concentration and speciation in soils. An understanding of the source, mobility, and dispersion of Tl is necessary to evaluate the environmental impact of Tl pollution cases. In this paper, we examine the Tl source and dispersion in two areas affected by abandoned mine facilities whose residues remain dumped on-site affecting to soils and sediments of natural water courses near Madrid city (Spain). Total Tl contents and partitioning in soil solid phases as determined by means of a sequential extraction procedure were also examined in soils along the riverbeds of an ephemeral and a permanent streams collecting water runoff and drainage from the mines wastes. Lastly, electronic microscopy and cathodoluminescence probe are used as a suitable technique for Tl elemental detection on thallium-bearing phases. Tl was found mainly bound to quartz and alumino-phyllosilicates in both rocks and examined soils. Besides, Tl was also frequently found associated to organic particles and diatom frustules in all samples from both mine scenarios. These biogenic silicates may regulate the transfer of Tl into the soil-water system. PMID:26218566

  18. Monitoring of soil chemical characteristics with time as affected by irrigation with saline water

    International Nuclear Information System (INIS)

    A lysimeter study was conducted to investigate the effect of irrigation with saline water on soil chemical characteristics at two depth (0-20) and (20-40 cm).Both fertilized (60, 120 KgN/ha) and unfertilized (0) soil were simulated in a total of 84 lysimeter. Data indicated that the electric conductivity (EC) values tended to increase with time intervals also EC-values as affected by soil depth after 105 days were high in 20 cm depth as compared to 40 cm depth. Chloride concentration did not reflect great variations as affected by time of nitrogen application where the values were nearly closed to each other. At the end of the experiment, much of Cl- content was occurred in the second layer of soil depth (20-40) as compared to depth of 0-20 cm. This was the case under all salinity levels. The irrigation with fresh water did not reflect any significant different in EC values between 120 KgN/ha , 60 KgN/ha or soil depth, however, it tend to increase with increasing water salinity levels. There were no much differences between the nitrogen application time (T1, T2 and T3). In contrast with Cl-, sodium was remained in the upper layer of 0-20 cm soil depth but still increase with increasing water salinity levels.

  19. Monitoring of Soil Chemical Characteristics with Time as Affected by Irrigation with Saline Water

    International Nuclear Information System (INIS)

    A lysimeter study was conducted to investigate the effect of irrigation with saline water on soil chemical characteristics at two depth (0-20) and (20-40 cm). Both fertilized (60, 120 Kg N/ha) and unfertilized (0) soil were simulated in a total of 84 lysimeter. Data indicated that the electric conductivity (EC) values tended to increase with time intervals also EC- values as affected by soil depth after 105 days were high in 20 cm depth as compared to 40 cm depth. Chloride concentration did not reflect great variations as affected by time of nitrogen application where the values were nearly closed to each other. At the end of the experiment, much of Cl- content was occurred in the second layer of soil depth (20-40) as compared to depth of 0-20 cm. This was the case under all salinity levels. The irrigation with fresh water did not reflect any significant different in EC values between 120 Kg N/ha, 60 Kg N/ha or soil depth, however, it tend to increase with increasing water salinity levels. There were no much differences between the nitrogen application time (T1, T2 and T3). In contrast with Cl-, sodium was remained in the upper layer of 0-20 cm soil depth but still increase with increasing water salinity levels.

  20. Assessment of radionuclides in the drone affected soils of North Waziristan Agency and Orakzai Agency (abstract)

    International Nuclear Information System (INIS)

    When the drone affected soils of North Waziristan and Orakzai Agency were exposed to high resolution gamma ray spectrometry technique to determine the activity concentration levels the results were quite alarming. The results revealed that the mean concentration for the activity of the natural radionuclides including /sup 226/Ra, /sup 232/Th, and /sup 40/K were 42.37 +- 1.85, 47.18 +- 3.45 and 471.28 +- 23.77 Bq kg/sup -1/ respectively. On the other hand the anthropogenic activities were adding radioactive Cs 137 to soils of drone affected areas of North Waziristan and Orakzai Agency with the mean activity concentration of 5.95 +- 0.25 Bq kg/sup -1/. The maximum activity concentration of /sup 137/Cs was in North Waziristan affected soil with the value of 15.15 +- 0.39. /sup 137/Cs is an anthropogenic radionuclide produced as a fission product. However the presence of /sup 137/Cs in all the soil samples reveals the anthropogenic changes in the soils. The exact source of the introduction of /sup 137/Cs is assumed to be drone bombardment. /sup 137/Cs has radioactive half life of 30.17 years and it decays by emitting gamma and beta radiations. These gamma radiations can create havoc in our environment. (author)

  1. Nitrous Oxide and Methane Emissions as Affected by Water, Soil and Nitrogen

    Institute of Scientific and Technical Information of China (English)

    XIONG Zheng-Qin; XING Guang-Xi; ZHU Zhao-Liang

    2007-01-01

    Specific management of water regimes,soil and N in China might play an important role in regulating N2O and CH4 emissions in rice fields.Nitrous oxide and methane emissions from alternate non-flooded/flooded paddies were monitored simultaneously during a 516-day incubation with lysimeter experiments.Two N sources (15N-(NH4)2SO4 and 15N-labeled milk vetch)were applied to two contrasting paddies:one derived from Xiashu loess(Loess)and one from Quaternary red clay(Clay).Both N2O and CH4 emissions were significantly higher in soil Clay than in soil Loess during the flooded period.For both soil,N2O emissions peaked at the transition periods shortly after the beginning of the flooded and non-flooded seasons.Soil type affected N2O emission patterns.In soil Clay,the emission peak during the transition period from non-flooded to flooded conditions was much higher than the peak during the transition period from flooded to non-flooded conditions.In soil Loess,the emission peak during the transition period from flooded to non-flooded conditions was obviously higher than the peak during the transition period from non-flooded to flooded conditions except for milk vetch treatment.Soil type also had a significant effect on CH4 emissions during the flooded season,over which the weighted average flux was 111 mg C m-2 h-1 and 2.2 mg C m-2 h-1 from Clay and Loess,respectively.Results indicated that it was the transition in the water regime that dominated N2O emissions while it was the soil type that dominated CH4 emissions during the flooded season.Anaerobic oxidation of methane possibly existed in soil Loess during the flooded season.

  2. Distribution and retention of Cs radioisotopes in soil affected by Fukushima nuclear plant accident

    International Nuclear Information System (INIS)

    There was a large release of radio cesium (134Cs and 137Cs) to the atmosphere during Fukushima Daiichi Nuclear Power Plant (FDNPP) accident and contaminated soil over a vast area, due to fallout activity. Therefore, studies on the behavior of radio cesium especially migration in soil and its retention on soil particles is very important for external dose assessment and root uptake. We have determined the sorption coefficient (Kd) for Cs using laboratory batch method in soil samples collected from a contaminated area affected by FDNPP accident and the effect of various soil parameters on the Kd value has been studied. We have noticed that Cs sorption is mostly influenced by cation exchange process and sorbed on the surface of clay particles. From vertical depth profile of Cs in soil shows most of it is retained on the top layer within 5cm thickness. Sequential extraction of soil using various reagents may be helpful to understand better on the mechanism of Cs retention. (author)

  3. On the structural factors of soil humic matter related to soil water repellence in fire-affected soils

    Science.gov (United States)

    Almendros, G.; González-Vila, F. J.; González-Pérez, J. A.; Knicker, H.; De la Rosa, J. M.; Dettweiler, C.; Hernández, Z.

    2012-04-01

    In order to elucidate the impact of forest fires on physical and chemical properties of the soils as well as on the chemical composition of the soil organic matter, samples from two Mediterranean soils with contrasted characteristics and vegetation (O horizon, Lithic Leptosols under Quercus ilex and Pinus pinaster) and one agricultural soil (Ap horizon, Luvisol) were heated at 350 °C in laboratory conditions for three successive steps up to 600 s. The C- and N-depletion in the course of the heating showed small changes up to an oxidation time of 300 s. On the other side, and after 600 s, considerable C-losses (between 21% in the Luvisol and 50% in the Leptosols) were observed. The relatively low N-depletion ca. 4% (Luvisol) and 21% (Leptosol under pine) suggested preferential loss of C and the subsequent relative enrichment of nitrogen. Paralleling the progressive depletion of organic matter, the Leptosols showed a significant increase of both pH and electrical conductivity. The former change paralleled the rapid loss of carboxyl groups, whereas the latter point to the relative enrichment of ash with a bearing on the concentration of inorganic ions, which could be considered a positive effect for the post-fire vegetation. The quantitative and qualitative analyses by solid-state 13C NMR spectra of the humic fractions in the samples subjected to successive heating times indicate significant concentration of aromatic structures newly-formed in the course of the dehydration and cyclization of carbohydrates (accumulation of black carbon-type polycyclic aromatic structures), and probably lipids and peptides. The early decarboxylation, in addition to the depletion of O-alkyl hydrophilic constituents and further accumulation of secondary aromatic structures resulted in the dramatic increase in the soil water drop penetration time. It was confirmed that this enhancement of the soil hydrophobicity is not related to an increased concentration of soil free lipid, but is

  4. Cropping history affects nodulation and symbiotic efficiency of distinct hairy vetch genotypes with resident soil rhizobia

    Science.gov (United States)

    Presence of compatible rhizobia strains is essential for nodulation and BNF of hairy vetch (Vicia villosa, HV). We evaluated how past HV cultivation affects nodulation and nitrogen fixation across host genotypes. Five groups of HV genotypes were inoculated with soil dilutions from six paired fields,...

  5. Investigations of Gamasina mites in natural and man-affected soils in Latvia (Acari: Mesostigmata)

    NARCIS (Netherlands)

    Salmane, I.

    2003-01-01

    Investigations of Gamasina mites in natural and man-affected soils in Latvia (Acari: Mesostigmata) A short overview is presented on Gamasina material collected in 22 natural and man-disturbed habitats in Latvia. Species diversity, average density and species dominance were investigated. Altogether 1

  6. Soil Erosion as Affected by Polyacrylamide Application Under Simulated Furrow Irrigation with Saline Water

    Institute of Scientific and Technical Information of China (English)

    DOU Chao-Yin; LI Fa-Hu; L. S.WU

    2012-01-01

    The reduction of soil and water losses under furrow.irrigation with saline water is important to environnental protection and agricultural production.The objective of this study was to determine the effect of polyacrylamide (pAM) application on soil infiltration and erosion under simulated furrow irrigation with saline water.Polyacrylamide was applied by dissolving it in irrigation water at the rates of 1.5,7.5,and 15.0 mg L-1 or spreading it as a powder on soil surface at the rates of 0.3,15,3.0,and 6.0 g m-2,respectively.The electrolyte concentration of tested irrigation water was 10 and 30 mmolc L-1 and its sodium adsorption ratio (SAR) was 0.5,10.0,and 20.0 (mmol(c) L-1)0.5.Distilled water was used as a control for irrigation water quality.Results indicated that the electrolyte concentration and SAR generally did not significantly affect soil and water losses after PAM application.Infiltration rate and total infiltration volume decreased with the increase of PAM application rate.Polyacrylamide application in both methods significantly reduced soil erosion,but PAM application rate did not significantly affect it.The solution PAM application was more effective in controlling soil erosion than the powdered PAM application,but the former exerted a greater adverse influence on soil infiltration than the latter.Under the same total amounts,the powdered PAM application resulted in a 38.2%-139.6% granter infiltration volume but a soil mass loss of 1.3-3.4 times greater than the solution PAM apllication.

  7. Organic matter protection as affected by the mineral soil matrix: allophanic vs. non-allophanic volcanic ash soils

    Science.gov (United States)

    Nierop, K. G. J.; Kaal, J.; Jansen, B.; Naafs, D. F. W.

    2009-04-01

    Volcanic ash soils (Andosols) contain the largest amounts of organic carbon of all mineral soil types. Chemical (complexes of organic matter with allophane, Al/Fe) and physical (aggregation) mechanisms are protecting the carbon from decomposition. While allophanic Andosols are dominated by short range order minerals such as allophane, imogolite and ferrihydrite, organic matter-Al/Fe complexes dominate non-allophanic Andosols. Consequently, chemical interactions between the mineral soil matrix and organic matter differ between these two soil types. This difference could potentially lead to different organic matter compositions. In this study, the organic matter of Ah horizons of an allophanic Andosol with a non-allophanic Andosol from Madeira Island is compared using analytical pyrolysis. Both volcanic soil types showed a relative decrease of lignin-derived pyrolysis products with depth, but this decrease was more pronounced in the allophanic Andosol. Polysaccharides were more abundant in the allophanic Ah horizon, particularly at lower depth, and this was also the case for the non-plant-derived N-containing polysaccharide chitin. Most likely, these biopolymers are adsorbed onto short range order minerals such as allophane and therefore were better protected in the allophanic Andosol. In addition, the higher chitin contents combined with the more pronounced lignin degradation suggests a higher fungal activity. Aliphatic pyrolysis products (n-alkenes/n-alkanes, fatty acids) were relatively more enriched in the non-allophanic Andosol. Lower microbial activity caused by the more acidic pH and higher levels of (toxic) aluminium are the most plausible reasons for the accumulation of these compounds in the non-allophanic Andosol. Although the allophanic and non-allophanic Andosol resembled each other in containing biopolymer groups of the same orders of magnitudes, in particular the contents of chitin and aliphatic compounds were distinctly affected by the differences in

  8. Biogeochemical weathering of serpentinites: An examination of incipient dissolution affecting serpentine soil formation

    International Nuclear Information System (INIS)

    Highlights: • Dissolution of primary minerals is important to porosity generation in serpentinites. • Mineral weathering extent in serpentinites follows the order Fe > Mg > Al rich minerals. • Fe-oxidizing bacteria may mediate Fe-rich primary and serpentine mineral alteration. • Serpentinite weathering is strongly impacted by degree of serpentinization. - Abstract: Serpentinite rocks, high in Mg and trace elements including Ni, Cr, Cd, Co, Cu, and Mn and low in nutrients such as Ca, K, and P, form serpentine soils with similar chemical properties resulting in chemically extreme environments for the biota that grow upon them. The impact of parent material on soil characteristics is most important in young soils, and therefore the incipient weathering of serpentinite rock likely has a strong effect on the development of serpentine soils and ecosystems. Additionally, porosity generation is a crucial process in converting rock into a soil that can support vegetation. Here, the important factors affecting the incipient weathering of serpentinite rock are examined at two sites in the Klamath Mountains, California. Serpentinite-derived soils and serpentinite rock cores were collected in depth profiles from each sampling location. Mineral dissolution in weathered serpentinite samples, determined by scanning electron microscopy, energy dispersive spectrometry, electron microprobe analyses, and synchrotron microXRD, is consistent with the order, from most weathered to least weathered: Fe-rich pyroxene > antigorite > Mg-rich lizardite > Al-rich lizardite. These results suggest that the initial porosity formation within serpentinite rock, impacting the formation of serpentine soil on which vegetation can exist, is strongly affected both by the presence of non-serpentine primary minerals as well as the composition of the serpentine minerals. In particular, the presence of ferrous Fe appears to contribute to greater dissolution, whereas the presence of Al within the

  9. Land-use systems affect Archaeal community structure and functional diversity in western Amazon soils

    Directory of Open Access Journals (Sweden)

    Acácio Aparecido Navarrete

    2011-10-01

    Full Text Available The study of the ecology of soil microbial communities at relevant spatial scales is primordial in the wide Amazon region due to the current land use changes. In this study, the diversity of the Archaea domain (community structure and ammonia-oxidizing Archaea (richness and community composition were investigated using molecular biology-based techniques in different land-use systems in western Amazonia, Brazil. Soil samples were collected in two periods with high precipitation (March 2008 and January 2009 from Inceptisols under primary tropical rainforest, secondary forest (5-20 year old, agricultural systems of indigenous people and cattle pasture. Denaturing gradient gel electrophoresis of polymerase chain reaction-amplified DNA (PCR-DGGE using the 16S rRNA gene as a biomarker showed that archaeal community structures in crops and pasture soils are different from those in primary forest soil, which is more similar to the community structure in secondary forest soil. Sequence analysis of excised DGGE bands indicated the presence of crenarchaeal and euryarchaeal organisms. Based on clone library analysis of the gene coding the subunit of the enzyme ammonia monooxygenase (amoA of Archaea (306 sequences, the Shannon-Wiener function and Simpson's index showed a greater ammonia-oxidizing archaeal diversity in primary forest soils (H' = 2.1486; D = 0.1366, followed by a lower diversity in soils under pasture (H' = 1.9629; D = 0.1715, crops (H' = 1.4613; D = 0.3309 and secondary forest (H' = 0.8633; D = 0.5405. All cloned inserts were similar to the Crenarchaeota amoA gene clones (identity > 95 % previously found in soils and sediments and distributed primarily in three major phylogenetic clusters. The findings indicate that agricultural systems of indigenous people and cattle pasture affect the archaeal community structure and diversity of ammonia-oxidizing Archaea in western Amazon soils.

  10. Compost amendment of sandy soil affects soil properties and greenhouse tomato productivity

    DEFF Research Database (Denmark)

    Arthur, Emmanuel; Cornelis, W.; Razzaghi, Fatemeh

    2012-01-01

    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...

  11. Soil hydraulic properties affected by topsoil thickness in cultivated switchgrass and corn-soybean rotation production systems

    Science.gov (United States)

    Loss of productive topsoil by soil erosion over time can reduce the productive capacity of soil and can significantly affect soil hydraulic properties. This study evaluated the effects of reduced topsoil thickness and perennial switchgrass (Panicum virgatum L.) versus corn (Zea mays L.)/soybean [Gly...

  12. Phosphorus geochemistry in a Brazilian semiarid mangrove soil affected by shrimp farm effluents.

    Science.gov (United States)

    Nóbrega, G N; Otero, X L; Macías, F; Ferreira, T O

    2014-09-01

    Wastewater discharge from shrimp farming is one of the main causes of eutrophication in mangrove ecosystems. We investigated the phosphorus (P) geochemistry in mangrove soils affected by shrimp farming effluents by carrying out a seasonal study of two mangrove forests (a control site (CS); a site affected by shrimp farm effluents (SF)). We determined the soil pH, redox potential (Eh), total organic carbon (TOC), total phosphorus (TP), and dissolved P. We also carried out sequential extraction of the P-solid phases. In SF, the effluents affected the soil physicochemical conditions, resulting in lower Eh and higher pH, as well as lower TOC and higher TP than in CS. Organic P forms were dominant in both sites and seasons, although to a lesser extent in SF. The lower TOC in SF was related to the increased microbial activity and organic matter decomposition caused by fertilization. The higher amounts of P oxides in SF suggest that the effluents alter the dominance of iron and sulfate reduction in mangrove soils, generating more reactive Fe that is available for bonding to phosphates. Strong TP losses were recorded in both sites during the dry season, in association with increased amounts of exchangeable and dissolved P. The higher bioavailability of P during the dry season may be attributed to increased mineralization of organic matter and dissolution of Ca-P in response to more oxidizing and acidic conditions. The P loss has significant environmental implications regarding eutrophication and marine productivity. PMID:24838803

  13. Soil water balance as affected by throughfall in gorse ( Ulex europaeus, L.) shrubland after burning

    Science.gov (United States)

    Soto, Benedicto; Diaz-Fierros, Francisco

    1997-08-01

    The role of fire in the hydrological behaviour of gorse shrub is studied from the point of view of its effects on vegetation cover and throughfall. In the first year after fire, throughfall represents about 88% of gross rainfall, whereas in unburnt areas it is 58%. Four years after fire, the throughfall coefficients are similar in burnt and unburnt plots (about 6096). The throughfall is not linearly related to vegetation cover because an increase in cover does not involve a proportional reduction in throughfall. The throughfall predicted by the two-parameter exponential model of Calder (1986, J. Hydrol., 88: 201-211) provides a good fit with the observed throughfall and the y value of the model reflects the evolution of throughfall rate. The soil moisture distribution is modified by fire owing to the increase of evaporation in the surface soil and the decrease of transpiration from deep soil layers. Nevertheless, the use of the old root system by sprouting vegetation leads to a soil water profile in which 20 months after the fire the soil water is similar in burnt and unburnt areas. Overall, soil moisture is higher in burnt plots than in unburnt plots. Surface runoff increases after a fire but does not entirely account for the increase in throughfall. Therefore the removal of vegetation cover in gorse scrub by fire mainly affects the subsurface water flows.

  14. Movement of Phosphorus in a Calcareous Soil as Affected by Humic Acid

    Institute of Scientific and Technical Information of China (English)

    DU Zhen-Yu; WANG Qing-Hua; LIU Fang-Chun; MA Hai-Lin; MA Bing-Yao; S.S.MALHI

    2013-01-01

    When humic acid (HA) and phosphorus (P) fertilizer are simultaneously applied to soil,HA may affect the movement of P.A laboratory incubation experiment was conducted to quantify the effects of a commercial HA product co-applied with monocalcium phosphate (MCP) on the distance of P movement and the concentration of P in various forms at different distances from the P fertilizer application site in a calcareous soil from northern China.Fertilizer MCP (at a rate equivalent to 26.6 kg P ha-1) was applied alone or in combination with HA (at 254.8 kg HA ha-1) to the surface of soil packed in cylinders (150 mm high and 50 mm internal diameter),and then incubated at 320 g kg-1 moisture content for 7 and 28 d periods.Extraction and analysis of each 2 mm soil layer in columns showed that the addition of HA to MCP increased the distance of P movement and the concentrations of water-extractable P,acid-extractable P and Olsen P in soil.The addition of HA to MCP could enhance P availability by increasing the distance of P movement and the concentration of extractable P in soil surrounding the P fertilizer.

  15. Soil amendment affects Cd uptake by wheat - are we underestimating the risks from chloride inputs?

    Science.gov (United States)

    Dahlin, A Sigrun; Eriksson, Jan; Campbell, Colin D; Öborn, Ingrid

    2016-06-01

    Many parts of the world are investigating the efficacy of recycling nutrient resources to agriculture from different industry and domestic sectors as part of a more circular economy. The complex nature of recycled products as soil amendments coupled to the large diversity of soil types and their inherent properties make it difficult to optimize the benefits and minimize the risks from potentially toxic elements often present in recycled materials. Here we investigated how wheat grain cadmium (Cd) concentration was affected by soil amendments, namely human urine and biogas digestate compared to traditional farm manures and mineral fertilizers. We show that Cl(-) inadvertently added to soils with e.g. urine or biogas digestate strongly increased crop Cd concentrations, largely by mobilizing inherent soil Cd. This resulted in wheat grain Cd levels that could result in exceeding recommended WHO limits for dietary intake. This was evident even in soils with low inherent Cd content and when Cd inputs were low. The future of a circular economy that helps to underpin global food security needs to ensure that the effects of applying complex materials to different types of agricultural land are fully understood and do not jeopardize food safety. Modified from Wivstad et al. (2009). PMID:26974588

  16. Do soil fertilization and forest canopy foliage affect the growth and photosynthesis of Amazonian saplings?

    Directory of Open Access Journals (Sweden)

    Nilvanda dos Santos Magalhães

    2014-02-01

    Full Text Available Most Amazonian soils are highly weathered and poor in nutrients. Therefore, photosynthesis and plant growth should positively respond to the addition of mineral nutrients. Surprisingly, no study has been carried out in situ in the central Amazon to address this issue for juvenile trees. The objective of this study was to determine how photosynthetic rates and growth of tree saplings respond to the addition of mineral nutrients, to the variation in leaf area index of the forest canopy, and to changes in soil water content associated with rainfall seasonality. We assessed the effect of adding a slow-release fertilizer. We determined plant growth from 2010 to 2012 and gas exchange in the wet and dry season of 2012. Rainfall seasonality led to variations in soil water content, but it did not affect sapling growth or leaf gas exchange parameters. Although soil amendment increased phosphorus content by 60 %, neither plant growth nor the photosynthetic parameters were influenced by the addition of mineral nutrients. However, photosynthetic rates and growth of saplings decreased as the forest canopy became denser. Even when Amazonian soils are poor in nutrients, photosynthesis and sapling growth are more responsive to slight variations in light availability in the forest understory than to the availability of nutrients. Therefore, the response of saplings to future increases in atmospheric [CO2] will not be limited by the availability of mineral nutrients in the soil.

  17. Sodic soil properties and sunflower growth as affected by byproducts of flue gas desulfurization.

    Directory of Open Access Journals (Sweden)

    Jinman Wang

    Full Text Available The main component of the byproducts of flue gas desulfurization (BFGD is CaSO(4, which can be used to improve sodic soils. The effects of BFGD on sodic soil properties and sunflower growth were studied in a pot experiment. The experiment consisted of eight treatments, at four BFGD rates (0, 7.5, 15 and 22.5 t ha(-1 and two leaching levels (750 and 1200 m(3 ha(-1. The germination rate and yield of the sunflower increased, and the exchangeable sodium percentage (ESP, pH and total dissolved salts (TDS in the soils decreased after the byproducts were applied. Excessive BFGD also affected sunflower germination and growth, and leaching improved reclamation efficiency. The physical and chemical properties of the reclaimed soils were best when the byproducts were applied at 7.5 t ha(-1 and water was supplied at 1200 m(3·ha(-1. Under these conditions, the soil pH, ESP, and TDS decreased from 9.2, 63.5 and 0.65% to 7.8, 2.8 and 0.06%, and the germination rate and yield per sunflower reached 90% and 36.4 g, respectively. Salinity should be controlled by leaching when sodic soils are reclaimed with BFGD as sunflower growth is very sensitive to salinity during its seedling stage.

  18. Salt—Water Dynamics in Highly Salinized Topsoil of Salt—Affected Soil During Water Infiltration

    Institute of Scientific and Technical Information of China (English)

    WANGXUE-FENG; YOUWEN-RUI; 等

    1991-01-01

    Continuous monitoring of salt and water movement in the soil profile of highly salinized topsoil under steadystate infiltration was conducted.It gives that salt and water dynamics during convection-diffusion period can be divided into three stages:1.formation of a salt peak,2.the salt peak moving downwards till the appearance of the summit of the salt peak,3.the salt peak moving further downwards with the peak value decreasing.Results show that the maximum salt peak appears at the same depth if soil texture and outflow condition are the same.Factors affecting salt and water movement and ion components in the outflow solution underinfiltration are discussed.

  19. Linking hydraulic properties of fire-affected soils to infiltration and water repellency

    Science.gov (United States)

    Moody, J.A.; Kinner, D.A.; Ubeda, X.

    2009-01-01

    Heat from wildfires can produce a two-layer system composed of extremely dry soil covered by a layer of ash, which when subjected to rainfall, may produce extreme floods. To understand the soil physics controlling runoff for these initial conditions, we used a small, portable disk infiltrometer to measure two hydraulic properties: (1) near-saturated hydraulic conductivity, Kf and (2) sorptivity, S(??i), as a function of initial soil moisture content, ??i, ranging from extremely dry conditions (??i water repellency that influences Kf and S(??i). Values of Kf ranged from 4.5 ?? 10-3 to 53 ?? 10-3 cm s-1 for ash; from 0.93 ?? 10-3 to 130 ?? 10-3 cm s-1 for reference soils; and from 0.86 ?? 10-3 to 3.0 ?? 10-3 cm s-1, for soil unaffected by fire, which had the lowest values of Kf. Measurements indicated that S(??i) could be represented by an empirical non-linear function of ??i with a sorptivity maximum of 0.18-0.20 cm s-0.5, between 0.03 and 0.08 cm3 cm-3. This functional form differs from the monotonically decreasing non-linear functions often used to represent S(??i) for rainfall-runoff modeling. The sorptivity maximum may represent the combined effects of gravity, capillarity, and adsorption in a transitional domain corresponding to extremely dry soil, and moreover, it may explain the observed non-linear behavior, and the critical soil-moisture threshold of water repellent soils. Laboratory measurements of Kf and S(??i) are the first for ash and fire-affected soil, but additional measurements are needed of these hydraulic properties for in situ fire-affected soils. They provide insight into water repellency behavior and infiltration under extremely dry conditions. Most importantly, they indicate how existing rainfall-runoff models can be modified to accommodate a possible two-layer system in extremely dry conditions. These modified models can be used to predict floods from burned watersheds under these initial conditions.

  20. Scaling preferential flow processes in agricultural soils affected by tillage and trafficking at the field scale

    Science.gov (United States)

    Filipović, Vilim; Coquet, Yves

    2016-04-01

    There is an accumulation of experimental evidences that agricultural soils, at least the top horizons affected by tillage practices, are not homogeneous and present a structure that is strongly dependent on farming practices like tillage and trafficking. Soil tillage and trafficking can create compacted zones in the soil with hydraulic properties and porosity which are different from those of the non-compacted zones. This spatial variability can strongly influence transport processes and initiate preferential flow. Two or three dimensional models can be used to account for spatial variability created by agricultural practices, but such models need a detailed assessment of spatial heterogeneity which can be rather impractical to provide. This logically raises the question whether and how one dimensional model may be designed and used to account for the within-field spatial variability in soil structure created by agricultural practices. Preferential flow (dual-permeability) modelling performed with HYDRUS-1D will be confronted to classical modelling based on the Richards and convection-dispersion equations using HYDRUS-2D taking into account the various soil heterogeneities created by agricultural practices. Our goal is to derive one set of equivalent 1D soil hydraulic parameters from 2D simulations which accounts for soil heterogeneities created by agricultural operations. A field experiment was carried out in two phases: infiltration and redistribution on a plot by uniform sprinkle irrigation with water or bromide solution. Prior to the field experiment the soil structure of the tilled layer was determined along the face of a large trench perpendicular to the tillage direction (0.7 m depth and 3.1 m wide). Thirty TDR probes and tensiometers were installed in different soil structural zones (Δ compacted soil and Γ macroporous soil) which ensured soil water monitoring throughout the experiment. A map of bromide was constructed from small core samples (4 cm diam

  1. Effect of subsurface drainage on salt movement and distribution in salt-affected soils

    International Nuclear Information System (INIS)

    This study was carried out to evaluate different subsurface drainage treatments (combinations of depth and spacing) on salt movement and distribution. The soil is clay and the drainage was designed according to the steady-state condition (Hooghoudt's equation). Three spacings and two depths resulted in six drainage treatments. Soil samples represented the initial state of every treatment and after 14 months they (cotton followed by wheat) were analysed. The data show that drain depth has its effective role in salt leaching, while drain spacing has its effect on salt distribution in the soil profile. The leaching rate of each specific ion is also affected by the different drainage treatments. In general, the salt movement and distribution should be taken into consideration when evaluating the design of drainage systems. (author)

  2. Metal concentrations in soil paste extracts as affected by extraction ratio.

    Science.gov (United States)

    Tack, Filip M G; Dezillie, Nic; Verloo, Marc G

    2002-04-01

    Saturated paste extracts are sometimes used to estimate metal levels in the soil solution. To assess the significance of heavy-metal concentrations measured in saturation extracts, soil paste extracts were prepared with distilled water in amounts ranging from 60-200% of the moisture content at saturation. Trace metals behaved as if a small pool consistently was dissolved independent of the extraction ratio applied. Metal concentrations in the solution hence were not buffered by the solid phase, but the observed behaviour would allow the estimation of metal concentrations in the soil solution as a function of moisture content. The behaviour of iron and manganese suggested that some microbial reduction occurred. The intensity increased with increasing extraction ratio but not to the extent of affecting dissolution of trace elements. PMID:12805950

  3. Metal Concentrations in Soil Paste Extracts as Affected by Extraction Ratio

    Directory of Open Access Journals (Sweden)

    Filip M.G. Tack

    2002-01-01

    Full Text Available Saturated paste extracts are sometimes used to estimate metal levels in the soil solution. To assess the significance of heavy-metal concentrations measured in saturation extracts, soil paste extracts were prepared with distilled water in amounts ranging from 60–200% of the moisture content at saturation. Trace metals behaved as if a small pool consistently was dissolved independent of the extraction ratio applied. Metal concentrations in the solution hence were not buffered by the solid phase, but the observed behaviour would allow the estimation of metal concentrations in the soil solution as a function of moisture content. The behaviour of iron and manganese suggested that some microbial reduction occurred. The intensity increased with increasing extraction ratio but not to the extent of affecting dissolution of trace elements.

  4. Exo-polysaccharides (eps) producing biofilm bacteria in improving physico-chemical characteristics of the salt- affected soils

    International Nuclear Information System (INIS)

    A greenhouse study was conducted to compare the effect of inoculation of an EPS-producing bacterial strain (isolated from roots of wheat plants grown in a salt-affected soil) on the extent of soil aggregation around roots of wheat plants grown for 15 or 30 days in saline and non-saline soils. The results showed that the association of the inoculated EPS-producing bacterium was higher with roots of the inoculated wheat plants grown in saline than non-saline soil. This higher association of the EPS-producing bacterium with roots of wheat plants could be attributed to the effect of soluble salts content of the salt-affected soil. An increase in soil aggregation around roots of the inoculated wheat plants grown in saline soil over control could be beneficial in terms of improving physico-chemical characteristics of the salt-affected soils. Thus it could be concluded that inoculation of EPS- producing bacteria could help ameliorate fertility and productivity of the salt-affected. An enhanced productivity of the salt-affected soils would lead to improved environmental conditions of surroundings of the salt-affected lands. (author)

  5. Soil physical and hydrological properties as affected by long-term addition of various organic amendments

    Science.gov (United States)

    Eden, Marie; Völkel, Jörg; Mercier, Vincent; Labat, Christophe; Houot, Sabine

    2014-05-01

    The use of organic residues as soil amendments in agriculture not only reduces the amount of waste needing to be disposed of; it may also lead to improvements in soil properties, including physical and hydrological ones. The present study examines a long-term experiment called "Qualiagro", run jointly by INRA and Veolia Environment in Feucherolles, France (near Paris). It was initiated in 1998 on a loess-derived silt loam (787 g/kg silt, 152 g/kg clay) and includes ten treatments: four types of organic amendments and a control (CNT) each at two levels of mineral nitrogen (N) addition: minimal (Nmin) and optimal (Nopt). The amendments include three types of compost and farmyard manure (FYM), which were applied every other year at a rate of ca. 4 t carbon ha-1. The composts include municipal solid waste compost (MSW), co-compost of green wastes and sewage sludge (GWS), and biowaste compost (BIO). The plots are arranged in a randomized block design and have a size of 450 m²; each treatment is replicated four times (total of 40 plots). Ca. 15 years after the start of the experiment soil organic carbon (OC) had continuously increased in the amended plots, while it remained stable or decreased in the control plots. This compost- or manure-induced increase in OC plays a key role, affecting numerous dependant soil properties like bulk density, porosity and water retention. The water holding capacity (WHC) of a soil is of particular interest to farmers in terms of water supply for plants, but also indicates soil quality and functionality. Addition of OC may affect WHC in different ways: carbon-induced aggregation may increase larger-pore volume and hence WHC at the wet end while increased surface areas may lead to an increased retention of water at the dry end. Consequently it is difficult to predict (e.g. with pedotransfer functions) the impact on the amount of water available for plants (PAW), which was experimentally determined for the soils, along with the entire range

  6. Bacterial population succession and adaptation affected by insecticide application and soil spraying history

    Directory of Open Access Journals (Sweden)

    Hideomi eItoh

    2014-08-01

    Full Text Available Although microbial communities have varying degrees of exposure to environmental stresses such as chemical pollution, little is known on how these communities respond to environmental disturbances and how past disturbance history affects these community-level responses. To comprehensively understand the effect of organophosphorus insecticide application on microbiota in soils with or without insecticide-spraying history, we investigated the microbial succession in response to the addition of fenitrothion (O,O-dimethyl O-(3-methyl-p-nitrophenyl phosphorothioate, abbreviated as MEP by culture-dependent experiments and deep sequencing of 16S rRNA genes. Despite similar microbial composition at the initial stage, microbial response to MEP application was remarkably different between soils with and without MEP-spraying history. MEP-degrading microbes more rapidly increased in the soils with MEP-spraying history, suggesting that MEP-degrading bacteria might already exist at a certain level and could quickly respond to MEP re-treatment in the soil. Culture-dependent and -independent evaluations revealed that MEP-degrading Burkholderia bacteria are predominant in soils after MEP application, limited members of which might play a pivotal role in MEP-degradation in soils. Notably, deep sequencing also revealed that some methylotrophs dramatically increased after MEP application, strongly suggesting that these bacteria play a role in the consumption and removal of methanol, a harmful derivative from MEP-degradation, for better growth of MEP-degrading bacteria. This comprehensive study demonstrated the succession and adaptation processes of microbial communities under MEP application, which were critically affected by past experience of insecticide-spraying.

  7. Evaluation of soil characteristics potentially affecting arsenic concentration in paddy rice (Oryza sativa L.)

    Energy Technology Data Exchange (ETDEWEB)

    Bogdan, Katja, E-mail: katja.bogdan@pflern.uni-hannover.d [Institute of Plant Nutrition, Leibniz Universitaet Hannover, Herrenhaeuser Str. 2, 30419 Hannover (Germany); Schenk, Manfred K., E-mail: schenk@pflern.uni-hannover.d [Institute of Plant Nutrition, Leibniz Universitaet Hannover, Herrenhaeuser Str. 2, 30419 Hannover (Germany)

    2009-10-15

    Paddy rice may contribute considerably to the human intake of As. The knowledge of soil characteristics affecting the As content of the rice plant enables the development of agricultural measures for controlling As uptake. During field surveys in 2004 and 2006, plant samples from 68 fields (Italy, Po-area) revealed markedly differing As concentration in polished rice. The soil factors total As{sub (aquaregia)}, pH, grain size fractions, total C, plant available P{sub (CAL)}, poorly crystalline Fe{sub (oxal.)} and plant available Si{sub (Na-acetate)} content that potentially affect As content of rice were determined. A multiple linear regression analysis showed a significant positive influence of the total As{sub (aquaregia)} and plant available P{sub (CAL)} content and a negative influence of the poorly crystalline Fe{sub (oxal.)} content of the soil on the As content in polished rice and rice straw. Si concentration in rice straw varied widely and was negatively related to As content in straw and polished rice. - Field selection for total As, poorly crystalline Fe and plant available P in soil might contribute to control As content of paddy rice.

  8. Patterns of woody plant species diversity in Lebanon as affected by climatic and soil properties

    International Nuclear Information System (INIS)

    Lebanese biodiversity is threatened by tourist and urban development, political instability, over-collection of medicinal and aromatic plants, lack of compliance to the regulations prohibiting over-exploitation from the wild, over-grazing and forest fires. A large number of the native species have unexplored economic potential for either medicinal or ornamental use. One way to preserve these species is by propagation and reintroduction into appropriate habitats. However, this requires an understanding of the species biology and environment. The relationship of nine species to the soil and climatic conditions in eight sites along an altitudinal gradient was studied. Individual species were counted and identified within transects at each site. Climatic data were collected and soil samples were taken and analyzed for soil texture, soil pH, EC, CaCO3, organic matter content and the following nutrients: Ca, Mn, Na, Fe, P, K, Cu, Mg, and Zn. Each ecosystem had a unique environment that could be described using the first two factors (70.3 % of variation) in a Factor Analysis of the six most important variables. Some species densities were affected by soil conditions (the first factor) while climatic conditions (the second factor) explained the densities of other species. Recommendations are made for the in-situ and ex-situ preservations of the nine species and their ecosystems.(author)

  9. The Electrochemical Properties of Biochars and How They Affect Soil Redox Properties and Processes

    Directory of Open Access Journals (Sweden)

    Stephen Joseph

    2015-07-01

    Full Text Available Biochars are complex heterogeneous materials that consist of mineral phases, amorphous C, graphitic C, and labile organic molecules, many of which can be either electron donors or acceptors when placed in soil. Biochar is a reductant, but its electrical and electrochemical properties are a function of both the temperature of production and the concentration and composition of the various redox active mineral and organic phases present. When biochars are added to soils, they interact with plant roots and root hairs, micro-organisms, soil organic matter, proteins and the nutrient-rich water to form complex organo-mineral-biochar complexes Redox reactions can play an important role in the development of these complexes, and can also result in significant changes in the original C matrix. This paper reviews the redox processes that take place in soil and how they may be affected by the addition of biochar. It reviews the available literature on the redox properties of different biochars. It also reviews how biochar redox properties have been measured and presents new methods and data for determining redox properties of fresh biochars and for biochar/soil systems.

  10. Changes in canopy structure and ant assemblages affect soil ecosystem variables as a foundation species declines

    OpenAIRE

    Ellison, Aaron M.; Kendrick, J.A.; Classen, A.T.; Ribbons, R.R.

    2015-01-01

    The decline of Tsuga canadensis (eastern hemlock) – a foundation tree species – due to infestation by Adelges tsugae (hemlock woolly adelgid) or its complete removal from a stand by salvage logging dramatically affects associated faunal assemblages. Among these assemblages, species composition (richness and abundance) of ants increases rapidly as T. canadensis is lost from the stands. Because ants live and forage at the litter-soil interface, we hypothesized that environmental changes caused ...

  11. Vineyard floor management affects soil, plant nutrition, and grape yield and quality

    OpenAIRE

    Smith, Richard; Bettiga, Larry; Cahn, Michael; Baumgartner, K.; L E Jackson; Bensen, Tiffany

    2008-01-01

    Management of the vineyard floor affects soil and crop productivity, as well as runoff and sediment that leave the vineyard. In Monterey County, weed control is typically conducted in a 4-foot-wide area under the vines, while cover crops are planted in the middles between vine rows. This 5-year multidisciplinary study in a low rainfall vineyard evaluated the impact of weed control strategies (cultivation, pre-emergence and post-emergence herbicides) in the vine rows, factorially arranged with...

  12. Soil water retention and structure stability as affected by water quality

    Directory of Open Access Journals (Sweden)

    Amrakh I. Mamedov

    2014-04-01

    Full Text Available In arid and semi-arid zones with a short water resources studying the effects of water quality on soil water retention and structure is important for the development of effective soil and water conservation and management practices. Three water qualities (electrical conductivity, EC ~ 2, 100 and 500 μS cm-1 with a low SAR representing rain, canal-runoff and irrigation water respectively and semi-arid loam and clay soils were tested to evaluate an effect of soil texture and water quality on water retention, and aggregate and structure stability using the high energy moisture characteristic (HEMC method. The water retention curves obtained by the HEMC method were characterized by the modified van Genuchten (1980 model that provides (i model parameters α and n, which represent the location (of the inflection point and the steepness of the S-shaped water retention curve respectively, and (ii a volume of drainable pores (VDP, which is an indicator for the quantity of water released by the tested sample over the range of suction studied, and modal suction (MS, which corresponds to the most frequent pore sizes, and soil structure index, SI =VDP/MS. Generally (i treatments significantly affected the shape of the water retention curves (α and n and (ii contribution of soil type, water EC, and wetting rate and their interaction had considerable effect on the stability induces and model parameters. Most of changes due to the water quality and wetting condition were in the range of matric potential (ψ, 1.2-2.4; and 2.4-5.0 J kg-1 (pore size 125-250 μm and 60-125 μm. The VDP, SI and α increased, and MS and n decreased with the increase in clay content, water EC and the decrease in rate of aggregate wetting. The SI increased exponentially with the increase in VDP, and with the decrease in MS. Contribution of water EC on stability indices and model parameters was not linear and was soil dependent, and could be more valuable at medium water EC. Effect of

  13. Impacts of airborne pollutants on soil fauna

    Czech Academy of Sciences Publication Activity Database

    Rusek, Josef; Marshall, V. G.

    2000-01-01

    Roč. 31, - (2000), s. 395-423. ISSN 0066-4162 R&D Projects: GA ČR GA206/93/0276; GA ČR GA206/99/1416; GA AV ČR IAA6066702; GA AV ČR KSK2017602 Institutional research plan: CEZ:AV0Z6066911 Subject RIV: EH - Ecology, Behaviour Impact factor: 6.195, year: 2000

  14. Biochar affects soil organic matter cycling and microbial functions but does not alter microbial community structure in a paddy soil.

    Science.gov (United States)

    Tian, Jing; Wang, Jingyuan; Dippold, Michaela; Gao, Yang; Blagodatskaya, Evgenia; Kuzyakov, Yakov

    2016-06-15

    The application of biochar (BC) in conjunction with mineral fertilizers is one of the most promising management practices recommended to improve soil quality. However, the interactive mechanisms of BC and mineral fertilizer addition affecting microbial communities and functions associated with soil organic matter (SOM) cycling are poorly understood. We investigated the SOM in physical and chemical fractions, microbial community structure (using phospholipid fatty acid analysis, PLFA) and functions (by analyzing enzymes involved in C and N cycling and Biolog) in a 6-year field experiment with BC and NPK amendment. BC application increased total soil C and particulate organic C for 47.4-50.4% and 63.7-74.6%, respectively. The effects of BC on the microbial community and C-cycling enzymes were dependent on fertilization. Addition of BC alone did not change the microbial community compared with the control, but altered the microbial community structure in conjunction with NPK fertilization. SOM fractions accounted for 55% of the variance in the PLFA-related microbial community structure. The particulate organic N explained the largest variation in the microbial community structure. Microbial metabolic activity strongly increased after BC addition, particularly the utilization of amino acids and amines due to an increase in the activity of proteolytic (l-leucine aminopeptidase) enzymes. These results indicate that microorganisms start to mine N from the SOM to compensate for high C:N ratios after BC application, which consequently accelerate cycling of stable N. Concluding, BC in combination with NPK fertilizer application strongly affected microbial community composition and functions, which consequently influenced SOM cycling. PMID:26974565

  15. Does temperature of charcoal creation affect subsequent mineralization of soil carbon and nitrogen?

    Science.gov (United States)

    Pelletier-Bergeron, S.; Bradley, R.; Munson, A. D.

    2012-04-01

    Forest fire is the most common form of natural disturbance of boreal forest ecosystems and has primordial influence on successional processes. This may be due in part to the pre-disturbance vegetation development stage and species composition, but these successional pathways could also vary with differences in fire behavior and consequently in fire intensity, defined as the energy released during various phases of a fire. Fire intensity may also affect soil C and N cycling by affecting the quality of the charcoal that is produced. For example, the porosity of coal tends to increase with increasing temperature at which it is produced Higher porosity would logically increase the surface area to which dissolved soil molecules, such as tannins and other phenolics, may be adsorbed. We report on a microcosm study in which mineral and organic soils were jointly incubated for eight weeks with a full factorial array of treatments that included the addition of Kalmia tannins, protein, and wood charcoal produced at five different temperatures. A fourth experimental factor comprised the physical arrangement of the material (stratified vs. mixed), designed to simulate the effect of soil scarification after fire and salvage harvest. We examined the effects of these treatments on soil C and N mineralisation and soil microbial biomass. The furnace temperature at which the charcoal was produced had a significant effect on its physico-chemical properties; increasing furnace temperatures corresponded to a significant increase in % C (P<0.001), and a significant decrease in %O (P<0.001) and %H (P<0.001). Temperature also had significant impacts on microporosity (surface area and volume). Temperature of production had no effect (P=0.1355) on soil microbial biomass. We observed a linear decreasing trend (P<0.001) in qCO2 with increasing temperature of production, which was mainly reflected in a decline in basal respiration. Finally, we found a significant interaction (P=0.010) between

  16. Effects of Altered Temperature & Precipitation on Soil Bacterial & Microfaunal Communities as Mediated by Biological Soil Crusts

    Energy Technology Data Exchange (ETDEWEB)

    Neher, Deborah A. [University of Vermont

    2004-08-31

    With increased temperatures in our original pot study we observed a decline in lichen/moss crust cover and with that a decline in carbon and nitrogen fixation, and thus a probable decline of C and N input into crusts and soils. Soil bacteria and fauna were affected negatively by increased temperature in both light and dark crusts, and with movement from cool to hot and hot to hotter desert climates. Crust microbial biomass and relative abundance of diazotrophs was reduced greatly after one year, even in pots that were not moved from their original location, although no change in diazotroph community structure was observed. Populations of soil fauna moved from cool to hot deserts were affected more negatively than those moved from hot to hotter deserts.

  17. Fauna Europaea: Helminths (Animal Parasitic)

    NARCIS (Netherlands)

    D.I. Gibson; R.A. Bray; D. Hunt; B.B. Georgiev; T. Scholz; P.D. Harris; T.A. Bakke; T. Pojmanska; K. Niewiadomska; A. Kostadinova; V. Tkach; O. Bain; M.C. Durette-Desset; L. Gibbons; F. Moravec; A. Petter; Z.M. Dimitrova; K. Buchmann; E.T. Valtonen; Y. de Jong

    2014-01-01

    Fauna Europaea provides a public web-service with an index of scientific names (including important synonyms) of all living European land and freshwater animals, their geographical distribution at country level (up to the Urals, excluding the Caucasus region), and some additional information. The Fa

  18. Soil and Litter Animals.

    Science.gov (United States)

    Lippert, George

    1991-01-01

    A lesson plan for soil study utilizes the Tullgren extraction method to illustrate biological concepts. It includes background information, equipment, collection techniques, activities, and references for identification guides about soil fauna. (MCO)

  19. Soil Properties and Wheat Growth and Nutrients as Affected by Compost Amendment Under Saline Water Irrigation

    Institute of Scientific and Technical Information of China (English)

    A. M. MAHDY

    2011-01-01

    A greenhouse experiment was conducted to test and compare the suitability of saline compost and saline irrigation water for nutrient status amendment of a slightly productive sandy clay loam soil,to study the macronutrient utilization and dry matter production of wheat (Triticum aestivum c.v.Gemmiza 7) grown in a modified soil environment and to determine the effects of compost and saline irrigation water on soil productivity.The sandy clay loam soil was treated with compost of five rates (0,24,36,48,and 60 m3 ha-1,equivalent to 0,3,4.5,and 6 g kg-1 soil,respectively) and irrigation water of four salinity levels (0.50 (tap water),4.9,6.3,and 8.7 dS m-1).The results indicated that at harvest,the electrical conductivity (EC) of the soil was significantly (P < 0.05) changed by the compost application as compared to thecontrol.In general,the soil salinity significantly increased with increasing application rates of compost.Soluble salts,K,C1,HCO3,Na,Ca,and Mg,were significantly increased by the compost treatment.Soil sodium adsorption ratio (SAR) was significantly affected by the salinity levels of the irrigation water,and showed a slight response to the compost application.The soil organic carbon content was also significantly (P < 0.05) affected by application of compost,with a maximum value of 31.03 g kg-1 recorded at the compost rate of 60 m3 ha-1 and the irrigation water salinity level of 8.7 dS m-1 and a minimum value of 12.05 g kg-1 observed in the control.The compost application produced remarkable increases in wheat shoot dry matter production.The maximum dry matter production (75.11 g pot-1) occurred with 60 m3 ha-1 compost and normal irrigation water,with a minimum of 19.83 g pot-1 with no addition of compost and irrigation water at a salinity level of 8.70 dS m-1.Significant increases in wheat shoot contents of K,N,P,Na,and C1 were observed with addition of compost.The relatively high shoot N values may be attributed to increases in N availability in

  20. Pyrene fate affected by humic acid amendment in soil slurry systems

    Directory of Open Access Journals (Sweden)

    McLean Joan E

    2008-09-01

    Full Text Available Abstract Background Humic acid (HA has been found to affect the solubility, mineralization, and bound residue formation of polycyclic aromatic hydrocarbons (PAHs. However, most of the studies on the interaction between HA and PAH concentrated on one or two of the three phases. Few studies have provided a simple protocol to demonstrate the overall effects of HA on PAH distribution in soil systems for all three phases. Methods In this study, three doses of standard Elliott soil HA (ESHA, 15, 187.5, and 1,875 μg ESHA/g soil slurry, were amended to soil slurry systems. 14C-pyrene was added to the systems along with non-radiolabeled pyrene; 14C and 14CO2 were monitored for each system for a period of 120 days. Results The highest amendment dose significantly increased the 14C fraction in the aqueous phase within 24 h, but not after that time. Pyrene mineralization was significantly inhibited by the highest dose over the 120-day study. While organic solvent extractable 14C decreased with time in all systems, non-extractable or bound 14C was significantly enhanced with the highest dose of ESHA addition. Conclusion Amendment of the highest dose of ESHA to pyrene contaminated soil was observed to have two major functions. The first was to mitigate CO2 production significantly by reducing 14CO2 from 14C pyrene mineralization. The second was to significantly increase stable bound 14C formation, which may serve as a remediation end point. Overall, this study demonstrated a practical approach for decontamination of PAH contaminated soil. This approach may be applicable to other organic contaminated environments where active bioremediation is taking place.

  1. Multiple factors affect diversity and abundance of ammonia-oxidizing microorganisms in iron mine soil.

    Science.gov (United States)

    Xing, Yi; Si, Yan-Xiao; Hong, Chen; Li, Yang

    2015-07-01

    Ammonia oxidation by microorganisms is a critical process in the nitrogen cycle. In this study, four soil samples collected from a desert zone in an iron-exploration area and others from farmland and planted forest soil in an iron mine surrounding area. We analyzed the abundance and diversity of ammonia-oxidizing archaea (AOA) and ammonia-oxidizing bacteria (AOB) in iron-mining area near the Miyun reservoir using ammonia monooxygenase. A subunit gene (amoA) as molecular biomarker. Quantitative polymerase chain reaction was applied to explore the relationships between the abundance of AOA and AOB and soil physicochemical parameters. The results showed that AOA were more abundant than AOB and may play a more dominant role in the ammonia-oxidizing process in the whole region. PCR-denaturing gradient gel electrophoresis was used to analyze the structural changes of AOA and AOB. The results showed that AOB were much more diverse than AOA. Nitrosospira cluster three constitute the majority of AOB, and AOA were dominated by group 1.1b in the soil. Redundancy analysis was performed to explore the physicochemical parameters potentially important to AOA and AOB. Soil characteristics (i.e. water, ammonia, organic carbon, total nitrogen, available phosphorus, and soil type) were proposed to potentially contribute to the distributions of AOB, whereas Cd was also closely correlated to the distributions of AOB. The community of AOA correlated with ammonium and water contents. These results highlight the importance of multiple drivers in microbial niche formation as well as their affect on ammonia oxidizer composition, both which have significant consequences for ecosystem nitrogen functioning. PMID:25860433

  2. Biological soil crusts emit large amounts of NO and HONO affecting the nitrogen cycle in drylands

    Science.gov (United States)

    Tamm, Alexandra; Wu, Dianming; Ruckteschler, Nina; Rodríguez-Caballero, Emilio; Steinkamp, Jörg; Meusel, Hannah; Elbert, Wolfgang; Behrendt, Thomas; Sörgel, Matthias; Cheng, Yafang; Crutzen, Paul J.; Su, Hang; Pöschl, Ulrich; Weber, Bettina

    2016-04-01

    Dryland systems currently cover ˜40% of the world's land surface and are still expanding as a consequence of human impact and global change. In contrast to that, information on their role in global biochemical processes is limited, probably induced by the presumption that their sparse vegetation cover plays a negligible role in global balances. However, spaces between the sparse shrubs are not bare, but soils are mostly covered by biological soil crusts (biocrusts). These biocrust communities belong to the oldest life forms, resulting from an assembly between soil particles and cyanobacteria, lichens, bryophytes, and algae plus heterotrophic organisms in varying proportions. Depending on the dominating organism group, cyanobacteria-, lichen-, and bryophyte-dominated biocrusts are distinguished. Besides their ability to restrict soil erosion they fix atmospheric carbon and nitrogen, and by doing this they serve as a nutrient source in strongly depleted dryland ecosystems. In this study we show that a fraction of the nitrogen fixed by biocrusts is metabolized and subsequently returned to the atmosphere in the form of nitric oxide (NO) and nitrous acid (HONO). These gases affect the radical formation and oxidizing capacity within the troposphere, thus being of particular interest to atmospheric chemistry. Laboratory measurements using dynamic chamber systems showed that dark cyanobacteria-dominated crusts emitted the largest amounts of NO and HONO, being ˜20 times higher than trace gas fluxes of nearby bare soil. We showed that these nitrogen emissions have a biogenic origin, as emissions of formerly strongly emitting samples almost completely ceased after sterilization. By combining laboratory, field, and satellite measurement data we made a best estimate of global annual emissions amounting to ˜1.1 Tg of NO-N and ˜0.6 Tg of HONO-N from biocrusts. This sum of 1.7 Tg of reactive nitrogen emissions equals ˜20% of the soil release under natural vegetation according

  3. Fractionation of Added Cadmium in Submerged Soils as Affected by Organic Materials

    Institute of Scientific and Technical Information of China (English)

    WANGGUO; GAOSHAN; 等

    1999-01-01

    The effect of three organic materials(rice straw,Chinese milk vetch and pig manure)on the fractionation of cadmium added into two soils(a red soil and a fluvo-aquic soil) was studied using submerged incubation experiment.The organic materials increased soil soild organic carbon(SOC),pH value,the concentration of active Si in all the treatments and active Fe and Mn in some treatments.Accumulated SOC caused directly the increase of Cd bound to solid organic matter and consequently the decrease of exchangeable Cd.Higher active Si and pH,as well as lower Eh,were also responsible for the reduction of exchangeable Cd.Cd bound to mn oxide was positively correlated with pH values and rose significantly after one-month incubation,but decreased after three-month incubation.Cd bound to amporphous Fe oxide increased with the incubation time,but was not affected significantly by adding organic materials.

  4. Radiation use-efficiency of field beans as affected by soil phosphorus management

    International Nuclear Information System (INIS)

    A simple approach to modeling dry matter production is based on the assumption that radiation‐use efficiency (RUE), which is the amount of dry weight produced per unit of intercepted photosynthetically active radiation (IPAR), is relatively constant for crops adequately supplied with water and nutrients. Recent evidences, however, indicate that RUE is not constant but is strongly affected by environment. Soil stresses also appear to affect RUE but few responses have been documented. Growth analysis data from a field experiment were used to compute RUE of field beans grown at differential phosphorus (P) regimes. The main objective of this study was to assess the effects of soil P management on RUE. Applied P rates significantly increased RUE with values ranging from 0.86 g M/J at 0 kg P/ha to 1.09 g M/J at 200 kg P/ha. The relationship between total dry matter and cumulative EPAR was linear at low P regimes but resembled a curvilinear relationship at high P regimes. The RUE of beans under high soil P regimes was not constant but decreased over time. (author)

  5. Trifolium isthmocarpum Brot, a salt-tolerant wild leguminous forage crop in salt-affected soils

    Directory of Open Access Journals (Sweden)

    Kawtar Bennani

    2013-08-01

    Full Text Available Plant scientists are investigating the potential of previously unexploited legume species where environmental and biological stresses constrain the use of more conventional forage crops or where these species are better suited to the needs of sustainable agriculture. Trifolium isthmocarpum Brot., Moroccan clover, occurs as a weed in different habitats in Morocco. It grows in moderately saline areas, where traditional forage legumes cannot be cultivated; however, it has not been widely studied despite its good palatability. The salt tolerance was studied between natural field conditions and glasshouse. The extensive field studies have recorded the species in many different habitats ranging from healthy agricultural lands to abandoned saline areas. The plants maintained high nodulation capacity (ranging between 60% and 97% and nitrogenase activities (average 2.04 µmol C2H4 plant-1 h-1 in different habitats. Shoot systems of plants collected from salt-affected soils exhibited higher concentrations of Na+ and Cl- than those collected from healthy soils. Greenhouse experiments showed that germination percentage and vigor value of the studied species was not significantly (P > 0.05 affected at 160 mM NaCl, and that 25% of the germination ability was maintained when growing on substrats containing 240 mM NaCl. The growth rate of seedlings was not signicantly affected by 160 mM NaCl but was reduced by 38% under 240 mM NaCl. Leaf succulence and indices of leaf water status did not differ among the salt treatments, whereas relative water content was reduced by only 8% and water content at saturation increased by about 12% at high salt concentrations in the growing medium. This study suggest recommending the cultivation of T. isthmocarpum in salt-affected soils, which are widespread and pose a problem for the farmers of Morocco and other countries in the world’s arid belt.

  6. Distribution of radiocesium and radiostrontium in undisturbed soil affected by Fukushima nuclear power plant accident

    International Nuclear Information System (INIS)

    contaminated with 90Sr. To understand the geochemical behavior of Cs and Sr, distribution coefficient (Kd) and soil parameters have been determined experimentally and the important parameters affecting Cs and Sr sorption have been identified. The present study will be useful for understanding the migration processes and for long-term prediction of activity depth profiles in soil. (author)

  7. Degradation of soil fumigants as affected by initial concentration and temperature.

    Science.gov (United States)

    Ma, Q L; Gan, J; Papiernik, S K; Becker, J O; Yates, S R

    2001-01-01

    Soil fumigation using shank injection creates high fumigant concentration gradients in soil from the injection point to the soil surface. A temperature gradient also exists along the soil profile. We studied the degradation of methyl isothiocyanate (MITC) and 1,3-dichloropropene (1,3-D) in an Arlington sandy loam (coarse-loamy, mixed, thermic Haplic Durixeralf) at four temperatures and four initial concentrations. We then tested the applicability of first-order, half-order, and second-order kinetics, and the Michaelis-Menten model for describing fumigant degradation as affected by temperature and initial concentration. Overall, none of the models adequately described the degradation of MITC and 1,3-D isomers over the range of the initial concentrations. First-order and half-order kinetics adequately described the degradation of MITC and 1,3-D isomers at each initial concentration, with the correlation coefficients greater than 0.78 (r2> 0.78). However, the derived rate constant was dependent on the initial concentration. The first-order rate constants varied between 6 and 10x for MITC for the concentration range of 3 to 140 mg kg(-1), and between 1.5 and 4x for 1,3-D isomers for the concentration range of 0.6 to 60 mg kg(-1), depending on temperature. For the same initial concentration range, the variation in the half-order rate constants was between 1.4 and 1.7x for MITC and between 3.1 and 6.1x for 1,3-D isomers, depending on temperature. Second-order kinetics and the Michaelis-Menten model did not satisfactorily describe the degradation at all initial concentrations. The degradation of MITC and 1,3-D was primarily biodegradation, which was affected by temperature between 20 and 40 degrees C, following the Arrhenius equation (r2 > 0.74). PMID:11476506

  8. Does deciduous tree species identity affect carbon storage in temperate soils?

    Science.gov (United States)

    Jungkunst, Hermann; Schleuß, Per; Heitkamp, Felix

    2015-04-01

    Forest soils contribute roughly 70 % to the global terrestrial soil organic carbon (SOC) pool and thus play a vital role in the global carbon cycle. It is less clear, however, whether temperate tree species identity affects SOC storage beyond the coarse differentiation between coniferous and deciduous trees. The most important driver for soil SOC storage definitely is the fine mineral fraction (clay and fine silt) because of its high sorption ability. It is difficult to disentangle any additional biotic effects since clay and silt vary considerably in nature. For experimental approaches, the process of soil carbon accumulation is too slow and, therefore, sound results cannot be expected for decades. Here we will present our success to distinguish between the effects of fine particle content (abiotic) and tree species composition (biotic) on the SOC pool in an old-growth broad-leaved forest plots along a tree diversity gradient , i.e., 1- (beech), 3- (plus ash and lime tree)- and 5-(plus maple and hornbeam) species. The particle size fractions were separated first and then the carbon concentrations of each fraction was measured. Hence, the carbon content per unit clay was not calculated, as usually done, but directly measured. As expected, the variation in SOC content was mainly explained by the variations in clay content but not entirely. We found that the carbon concentration per unit clay and fine silt in the subsoil was by 30-35% higher in mixed than in monospecific stands indicating a significant species identity or species diversity effect on C stabilization. In contrast to the subsoil, no tree species effects was identified for the topsoil. Indications are given that the mineral phase was already carbon saturated and thus left no more room for a possible biotic effect. Underlying processes must remain speculative, but we will additionally present our latest microcosm results, including isotopic signatures, to underpin the proposed deciduous tree species

  9. Water treatment residuals and biosolids co-applications affect phosphatases in a semi-arid rangeland soil

    Science.gov (United States)

    Biosolids and water treatment residuals (WTR) land co-application has not been extensively studied, but may be beneficial by sorbing excess biosolids-borne or soil P onto WTR, reducing the likelihood of off-site movement. Reduction of excess soil P may affect the role of specific P-cleaving enzymes...

  10. Selection pressure, cropping system and rhizosphere proximity affect atrazine degrader populations and activity in s-triazine adapted soil

    Science.gov (United States)

    Atrazine degrader populations and activity in s-triazine adapted soils are likely affected by interactions among and (or) between s-triazine application frequency, crop production system, and proximity to the rhizosphere. A field study was conducted on an s-triazine adapted soil to determine the ef...

  11. Changes in Soil Properties Under the Influences of Cropping and Drip Irrigation During the Reclamation of Severe Salt-Affected Soils

    Institute of Scientific and Technical Information of China (English)

    TAN Jun-li; KANG Yue-hu

    2009-01-01

    Reclamation of salt-affected land plays an important role in mitigating the pressure of agricultural land due to competition with industry and construction in China. Drip irrigation was found to be an effective method to reclaim salt-affected land. In order to improve the effect of reclamation and sustainability of salt-affected land production, a field experiment (with reclaimed 1-3 yr fields) was carried out to investigate changes in soil physical, chemical, and biological properties during the process of reclamation with cropping maize and drip irrigation. Results showed that soil bulk density in 0-20 cm soil layer decreased from 1.71 g cm-3 in unreclaimed land to 1.44 g cm-3 in reclaimed 3 yr fields, and saturated soil water content of 0-10 cm layer increased correspondingly from 20.3 to 30.2%. Both soil salinity and pH value in 0-40 cm soil layer dropped markedly after reclaiming 3 yr. Soil organic matter content reduced, while total nitrogen, total phosphorus, and total potassium all tended to increase after cropping and drip irrigation. The quantities of bacteria, actinomycete, and fungi in 0-40 cm soil layer all greatly increased with increase of reclaimed years, and they tended to distribute homogeneously in 0-40 cm soil profile. The urease activity and alkaline phosphatase activity in 0-40 era soil layers were also enhanced, but the sucrase activity was not greatly changed. These results indicated that after crop cultivation and drip irrigation, soil physical environment and nutrients status were both improved. This was benefit for microorganism's activity and plant's growth.

  12. SOIL QUALITY AND CROP PRODUCTIVITY AS AFFECTED BY DIFFERENT SOIL MANAGEMENT SYSTEMS IN ORGANIC AGRICULTURE "TILMAN-ORG Session"

    OpenAIRE

    Willekens, Koen; Vandecasteele, Bart; De Vliegher, Alex

    2014-01-01

    A multi-year trial was conducted to compare soil management strategies (tillage and fertilization) with regard to their effect on crop performance and soil quality. Two soil management systems were assessed. Farm compost application was combined with reduced non-inversion tillage, whereas animal manure was incorporated by conventional tillage with a moldboard plough. With regard to soil quality, a reduced tillage practice in combination with compost application seemed to be favorable for soil...

  13. Response of oxidative enzyme activities to nitrogen deposition affects soil concentrations of dissolved organic carbon

    Science.gov (United States)

    Waldrop, M.P.; Zak, D.R.

    2006-01-01

    Recent evidence suggests that atmospheric nitrate (NO3- ) deposition can alter soil carbon (C) storage by directly affecting the activity of lignin-degrading soil fungi. In a laboratory experiment, we studied the direct influence of increasing soil NO 3- concentration on microbial C cycling in three different ecosystems: black oak-white oak (BOWO), sugar maple-red oak (SMRO), and sugar maple-basswood (SMBW). These ecosystems span a broad range of litter biochemistry and recalcitrance; the BOWO ecosystem contains the highest litter lignin content, SMRO had intermediate lignin content, and SMBW leaf litter has the lowest lignin content. We hypothesized that increasing soil solution NO 3- would reduce lignolytic activity in the BOWO ecosystem, due to a high abundance of white-rot fungi and lignin-rich leaf litter. Due to the low lignin content of litter in the SMBW, we further reasoned that the NO3- repression of lignolytic activity would be less dramatic due to a lower relative abundance of white-rot basidiomycetes; the response in the SMRO ecosystem should be intermediate. We increased soil solution NO3- concentrations in a 73-day laboratory incubation and measured microbial respiration and soil solution dissolved organic carbon (DOC) and phenolics concentrations. At the end of the incubation, we measured the activity of ??-glucosidase, N-acetyl-glucosaminidase, phenol oxidase, and peroxidase, which are extracellular enzymes involved with cellulose and lignin degradation. We quantified the fungal biomass, and we also used fungal ribosomal intergenic spacer analysis (RISA) to gain insight into fungal community composition. In the BOWO ecosystem, increasing NO 3- significantly decreased oxidative enzyme activities (-30% to -54%) and increased DOC (+32% upper limit) and phenolic (+77% upper limit) concentrations. In the SMRO ecosystem, we observed a significant decrease in phenol oxidase activity (-73% lower limit) and an increase in soluble phenolic concentrations

  14. Mite species (Acari: Mesostigmata new and rare to Polish fauna, inhabiting the soil of broadleaved forests dominated by small-leaved lime (Tilia cordata Mill. in Kwidzyn Forest District (N Poland

    Directory of Open Access Journals (Sweden)

    FALEŃCZYK-KOZIRÓG KATARZYNA

    2014-06-01

    Full Text Available During a two-year study on mites of the order Mesostigmata in broadleaved forest stands dominated by small-leaved lime (Tilia cordata Mill., 117 mite species were identified. Among them, 3 had been so far rarely recorded in Poland (Haemogamasus nidi, Stylochirus rovenensis and Eugamasus crassitarsis and 2 were classified as new to the Polish fauna (Veigaia sibirica and Digamasellus perpusillus.

  15. Relationships between soil properties and community structure of soil macroinvertebrates in oak-history forests along an acidic deposition gradient

    Energy Technology Data Exchange (ETDEWEB)

    Kuperman, R.G. [Argonne National Lab., IL (United States). Environmental Assessment Div.

    1996-02-01

    Soil macroinvertebrate communities were studied in ecologically analogous oak-hickory forests across a three-state atmospheric pollution gradient in Illinois, Indiana, and Ohio. The goal was to investigate changes in the community structure of soil fauna in study sites receiving different amounts of acidic deposition for several decades and the possible relationships between these changes and physico-chemical properties of soil. The study revealed significant differences in the numbers of soil animals among the three study sites. The sharply differentiated pattern of soil macroinvertebrate fauna seems closely linked to soil chemistry. Significant correlations of the abundance of soil macroinvertebrates with soil parameters suggest that their populations could have been affected by acidic deposition in the region. Abundance of total soil macroinvertebrates decreased with the increased cumulative loading of acidic deposition. Among the groups most sensitive to deposition were: earthworms gastropods, dipteran larvae, termites, and predatory beetles. The results of the study support the hypothesis that chronic long-term acidic deposition could aversely affect the soil decomposer community which could cause lower organic matter turnover rates leading to an increase in soil organic matter content in high deposition sites.

  16. Characterization on the rhizoremediation of petroleum contaminated soil as affected by different influencing factors

    Science.gov (United States)

    Tang, J.; Wang, R.; Niu, X.; Wang, M.; Zhou, Q.

    2010-06-01

    In this paper, pilot experiments were conducted to analyze the effect of different environmental factors on the rhizoremediation of petroleum contaminated soil. Different plant species (cotton, ryegrass, tall fescue, and alfalfa), addition of fertilizer, different concentration of TPH in soil, bioaugmentation with effective microbial agent (EMA) and PGPR, and remediation time were tested as influencing factors during bioremediation process of Total Petroleum Hydrocarbon (TPH). The result shows that the remediation process can be enhanced by different plants species with the following order: tall fescue > ryegrass > alfalfa > cotton. The degradation rate of TPH increased with increased fertilizer addition and moderate level of 20 g/m2 urea is best for both plant growth and TPH remediation. High TPH content is toxic to plant growth and inhibits the degradation of petroleum hydrocarbon with 5% TPH content showing the best degradation result in soil planted with ryegrass. Bioaugmentation with different bacteria and plant growth promoting rhizobacteria (PGPR) showed the following results for TPH degradation: cotton + EMA + PGPR > cotton + EMA > cotton + PGPR > cotton > control. Rapid degradation of TPH was found at the initial period of remediation caused by the activity of microorganisms, continuous increase was found from 30-90 d period and slow increase was found from 90 to 150 d. The result suggests that rhizoremediation can be enhanced with the proper control of different influencing factors that affect both plant growth and microbial activity in the rhizosphere environment.

  17. Characterization on the rhizoremediation of petroleum contaminated soil as affected by different influencing factors

    Directory of Open Access Journals (Sweden)

    J. Tang

    2010-06-01

    Full Text Available In this paper, pilot experiments were conducted to analyze the effect of different environmental factors on the rhizoremediation of petroleum contaminated soil. Different plant species (cotton, ryegrass, tall fescue, and alfalfa, addition of fertilizer, different concentration of TPH in soil, bioaugmentation with effective microbial agent (EMA and PGPR, and remediation time were tested as influencing factors during bioremediation process of Total Petroleum Hydrocarbon (TPH. The result shows that the remediation process can be enhanced by different plants species with the following order: tall fescue > ryegrass > alfalfa > cotton. The degradation rate of TPH increased with increased fertilizer addition and moderate level of 20 g/m2 urea is best for both plant growth and TPH remediation. High TPH content is toxic to plant growth and inhibits the degradation of petroleum hydrocarbon with 5% TPH content showing the best degradation result in soil planted with ryegrass. Bioaugmentation with different bacteria and plant growth promoting rhizobacteria (PGPR showed the following results for TPH degradation: cotton + EMA + PGPR > cotton + EMA > cotton + PGPR > cotton > control. Rapid degradation of TPH was found at the initial period of remediation caused by the activity of microorganisms, continuous increase was found from 30–90 d period and slow increase was found from 90 to 150 d. The result suggests that rhizoremediation can be enhanced with the proper control of different influencing factors that affect both plant growth and microbial activity in the rhizosphere environment.

  18. Land Management Effects on Biogeochemical Functioning of Salt-Affected Paddy Soils

    Institute of Scientific and Technical Information of China (English)

    C.QUANTIN; O.GRUNBERGER; N.SUVANNANG; E.BOURDON

    2008-01-01

    Most lowlands in Northeast Thailand (Isaan region) are cultivated with rice and large areas are affected by salinity,which drastically limits rice production.A field experiment was conducted during the 2003 rainy season to explore the interactions between salinity and land management in two fields representative of two farming practices:an intensively managed plot with organic inputs and efficient water management,and one without organic matter addition.Field measurements,including pH,Eh,electrical conductivity (EC),and soil solution chemistry,were performed at three depths,with a particular focus on Fe dynamics,inside and outside saline patches.High reducing conditions appeared after flooding particularly in plots receiving organic matter and reduction processes leading to oxide reduction and to the release of Fe and,to a lesser extend,Mn to the soil solution.Oxide reduction led to the consumption of H+ and the more the Fe reduction was,the higher the pH was,up to 6.5.Formation of hydroxy-green rust were likely to be at the origin of the pH stabilization.In the absence of organic amendments,high salinity prevented the establishment of the reduction processes and pH value remained around 4.Even under high reduction conditions,the Fe concentrations in the soil solution were below commonly observed toxic values and the amended plot had better rice production yield.

  19. Incorporating rice residues into paddy soils affects methylmercury accumulation in rice.

    Science.gov (United States)

    Zhu, Huike; Zhong, Huan; Wu, Jialu

    2016-06-01

    Paddy fields are characterized by frequent organic input (e.g., fertilization and rice residue amendment), which may affect mercury biogeochemistry and bioaccumulation. To explore potential effects of rice residue amendment on methylmercury (MMHg) accumulation in rice, a mercury-contaminated paddy soil was amended with rice root (RR), rice straw (RS) or composted rice straw (CS), and planted with rice. Incorporating RS or CS increased grain MMHg concentration by 14% or 11%. The observed increases could be attributed to the elevated porewater MMHg levels and thus enhanced MMHg uptake by plants, as well as increased MMHg translocation to grain within plants. Our results indicated for the first time that rice residue amendment could significantly affect MMHg accumulation in rice grain, which should be considered in risk assessment of MMHg in contaminated areas. PMID:26974480

  20. Environmental factors influencing trace house gas production in permafrost-affected soils

    Science.gov (United States)

    Walz, Josefine; Knoblauch, Christian; Böhme, Luisa; Pfeiffer, Eva-Maria

    2016-04-01

    The permafrost-carbon feedback has been identified as a major feedback mechanism to climate change. Soil organic matter (SOM) decomposition in the active layer and thawing permafrost is an important source of atmospheric carbon dioxide (CO2) and methane (CH4). Decomposability and potential CO2 and CH4 production are connected to the quality of SOM. SOM quality varies with vegetation composition, soil type, and soil depth. The regulating factors affecting SOM decomposition in permafrost landscapes are not well understood. Here, we incubated permafrost-affected soils from a polygonal tundra landscape in the Lena Delta, Northeast Siberia, to examine the influence of soil depth, oxygen availability, incubation temperature, and fresh organic matter addition on trace gas production. CO2 production was always highest in topsoil (0 - 10 cm). Subsoil (10 - 50 cm) and permafrost (50 - 90 cm) carbon did not differ significantly in their decomposability. Under anaerobic conditions, less SOM was decomposed than under aerobic conditions. However, in the absence of oxygen, CH4 can also be formed, which has a substantially higher warming potential than CO2. But, within the four-month incubation period (approximate period of thaw), methanogenesis played only a minor role with CH4 contributing 1-30% to the total anaerobic carbon release. Temperature and fresh organic matter addition had a positive effect on SOM decomposition. Across a temperature gradient (1, 4, 8°C) aerobic decomposition in topsoil was less sensitive to temperature than in subsoil or permafrost. The addition of labile plant organic matter (13C-labelled Carex aquatilis, a dominant species in the region) significantly increased overall CO2 production across different depths and temperatures. Partitioning the total amount of CO2 in samples amended with Carex material into SOM-derived CO2 and Carex-derived CO2, however, revealed that most of the additional CO2 could be assigned to the organic carbon from the amendment

  1. Management strategies to utilize salt affected soils. Isotopic and conventional research methods. Results of a co-ordinated research programme

    International Nuclear Information System (INIS)

    This document summarizes the results of a co-ordinated research programme on ''The Use of Nuclear Techniques for Improvement of Crop Production in Salt-affected Soils''. It aims at providing scientists experimental evidence of demonstrating technical feasibility of biological amelioration of salt affected soils as an alternative option of using expensive chemical amendments in soil reclamation complementing engineering structures of farm drainage systems or option of leaving the saline areas as barren lands in spite of the fact that arable agricultural lands have exhausted. 68 refs, 26 figs, 32 tabs

  2. How the sorption of benzene in soils contaminated with aromatic hydrocarbons is affected by the presence of biofuels

    Directory of Open Access Journals (Sweden)

    Maria Manuela Carvalho

    2015-04-01

    Full Text Available The increasing use of biofuels as additives to gasoline may have potential indirect effects on the efficiency of soil remediation technologies used to remediate fuel spills. This problem has not yet been studied. Sorption is one of the controlling processes in soil remediation. The effect of biofuels on sorption and phase distribution of contaminants by different natural soils has not been reported on the literature. The present work examines how two different biofuels, n-butanol and soybean biodiesel, affect benzene sorption in two naturally occurring subsoils (granite and limestone. Sorption isotherms were made with soils deliberately contaminated with benzene, benzene and n-butanol and benzene plus biodiesel, using lab-scale reactors operated at constant temperature, each one loaded with 700 grams of wet sterilized soil. For each type of soil, five isotherms were determined corresponding to different contamination profiles. It was concluded that sorption was strongly affected by the nature of the soil. The partition of benzene into the different phases of the soil was significantly affected by the presence of biofuels. The experimental data was fitted to conventional sorption models, Freundlich, Langmuir and a second order polynomial. Model parameters were determined using a non-linear least squares (NLLS optimization algorithm and showed a good agreement between experimental and fitted data.

  3. The levels and composition of persistent organic pollutants in alluvial agriculture soils affected by flooding.

    Science.gov (United States)

    Maliszewska-Kordybach, Barbara; Smreczak, Bozena; Klimkowicz-Pawlas, Agnieszka

    2013-12-01

    The concentrations and composition of persistent organic pollutants (POPs) were determined in alluvial soils subjected to heavy flooding in a rural region of Poland. Soil samples (n = 30) were collected from the upper soil layer from a 70-km(2) area. Chemical determinations included basic physicochemical properties and the contents of polychlorinated biphenyls (PCBs), hexachlorocyclohexanes (HCHs), dichlorodiphenyltrichloroethanes (DDTs) and polycyclic aromatic hydrocarbons (PAHs, 16 compounds). The median concentrations of Σ7PCB (PCB28 + PCB52 + PCB101 + PCB118 + PCB138 + PCB153 + PCB180), Σ3HCH (α-HCH + β-HCH + γ-HCH) and Σ3pp'(DDT + DDE + DDD) were 1.60 ± 1.03, 0.22 ± 0.13 and 25.18 ± 82.70 μg kg(-1), respectively. The median concentrations of the most abundant PAHs, phenanthrene, fluoranthene, pyrene, benzo[b]fluoranthene and benzo[a]pyrene were 50 ± 37, 38 ± 27, 29 ± 30, 45 ± 36 and 24 ± 22 μg kg(-1), respectively. Compared with elsewhere in the world, the overall level of contamination with POPs was low and similar to the levels in agricultural soils from neighbouring countries, except for benzo[a]pyrene and DDT. There was no evidence that flooding affected the levels of POPs in the studied soils. The patterns observed for PAHs and PCBs indicate that atmospheric deposition is the most important long-term source of these contaminants. DDTs were the dominant organochlorine pesticides (up to 99%), and the contribution of the parent pp' isomer was up to 50 % of the ΣDDT, which indicates the advantage of aged contamination. A high pp'DDE/pp'DDD ratio suggests the prevalence of aerobic transformations of parent DDT. Dominance of the γ isomer in the HCHs implies historical use of lindane in the area. The effect of soil properties on the POP concentrations was rather weak, although statistically significant links with the content of the <0.02-mm fraction, Ctotal or Ntotal were observed for some individual compounds in the PCB group. PMID:23877573

  4. Time-lapse electrical resistivity monitoring of salt-affected soil and groundwater

    Science.gov (United States)

    Hayley, Kevin; Bentley, L. R.; Gharibi, M.

    2009-07-01

    In order to develop and test a methodology for incorporating time-lapse electrical resistivity imaging (ERI) into the monitoring of salt-affected soil and groundwater, a multifaceted study including time-lapse electrical resistivity imaging, push tool conductivity (PTC), and core analysis was conducted to monitor the movement of a saline contaminant plume over the span of 3 years. The survey was done on a field site containing salt-affected soils and groundwater to depths of over 7 m. The site contained a tile drain system at approximately 2 m below ground level. Temperature and saturation changes were accounted for in electrical conductivity (EC) measurements to isolate changes in electrical conductivity due to changes in salt distribution. ERI inversion parameters were selected so that the inverse models gave the best match to PTC depth profiles and the best correlation with core EC data. A strong correlation between the core data and the ERI results was observed. Time-lapse ERI difference images showed that the subsurface EC distribution was consistent with preferential solute removal above the tile drains in some locations. The ERI-delineated reduction in solute concentration is consistent with nonuniform flushing due to depression-focused recharge. The addition of time-lapse ERI to the study allowed delineation of details of solute redistribution that would not have been possible with point measurements alone.

  5. Forage production and N2 fixation in mixed cropping of saltbush and shrubby medic grown on a salt affected soil

    International Nuclear Information System (INIS)

    Two experiments were conducted to evaluate dry matter, nitrogen yield, N2 fixation (Ndfa) and soil N uptake in saltbush (Atriplex halimus) and shrubby medic (Medicago arborea) grown either solely or in mixture on a salt affected soil, using 15N tracer techniques. In a pot experiment, the combined dry matter yield of both species was considerably higher than that of solely grown shrubs. The inclusion of saltbush in the mixed cropping system decreased soil N uptake by shrubby medic and enhanced %Ndfa without affecting amounts of N2 fixed. Under field conditions, estimated values of %Ndfa via delta15N natural abundance were relatively similar to those of the pot experiment using 15N enrichment method. It can be concluded that the use of mixed cropping system of shrubby medic and saltbush could be a promising bio-saline agricultural approach to utilize salt affected soils in terms of forage yield and N2-fixation. (Author)

  6. Relationships of soil physical and microbial properties with nitrous oxide emission affected by freeze-thaw event

    Institute of Scientific and Technical Information of China (English)

    Lianfeng WANG; Xin SUN; Yanjiang CAI; Hongtu XIE; Xudong ZHANG

    2008-01-01

    Freeze-thaw event often occurs in regions at mid-high latitude and high altitude.This event can affect soil physical and biological properties,such as soil water status,aggregate stability,and microbial biomass and community structure.Under its effects,the bio-indicators of soil microbes including the kinds and quantities of some specific amino sugars may vary,and the process and intensity of soil nitrogen transformation may change,which can result in an increase in nitrous oxide (N2O)production and emission,making the soil as the major source of N2O emission.This paper summarizes the research progress on the aspects mentioned above,and suggests further research directions on the theoretical problems of soil N2O production and emission under the effects of freeze-thaw event.

  7. Processes affecting the dissipation of the herbicide isoxaflutole and its diketonitrile metabolite in agricultural soils under field conditions.

    Science.gov (United States)

    Papiernik, Sharon K; Yates, Scott R; Koskinen, William C; Barber, Brian

    2007-10-17

    Two-year field dissipation studies were conducted in three soil types in Minnesota to examine the processes affecting the dissipation of the herbicide isoxaflutole and its phytotoxic diketonitrile metabolite (DKN) under relatively cool, wet soil conditions. Plots of cuphea were treated with isoxaflutole and potassium bromide, a nonsorbed, nondegraded tracer. Replicate soil cores were collected six times during the growing season to a depth of 1 m, and the bromide or herbicide concentration was measured in each of five depth increments. The dissipation half-life (DT50) of isoxaflutole + DKN was 8-18 days in each soil. Bromide and herbicide concentrations were low at depths >40 cm throughout the study, and herbicide concentrations in soil 100 days after application were usually undetectable. Simulation modeling using Hydrus-1D for the loam soil suggested that plant uptake was an important mechanism of dissipation. PMID:17880161

  8. Dissolved organic carbon and nitrogen mineralization strongly affect co2 emissions following lime application to acidic soil

    International Nuclear Information System (INIS)

    Emission of greenhouse gases from agricultural soils has main contribution to the climatic change and global warming. Dynamics of dissolved organic carbon (DOC) and nitrogen mineralization can affect CO/sub 2/ emission from soils. Influence of DOC and nitrogen mineralization on CO/sub 2/ emissions following lime application to acidic soil was investigated in current study. Laboratory experiment was conducted under aerobic conditions with 25% moisture contents (66% water-filled pore space) at 25 degree C in the dark conditions. Different treatments of lime were applied to acidic soil as follows: CK (control), L (low rate of lime: 0.2g lime / 100 g soil) and H (high rate of lime: 0.5g lime /100g soil). CO/sub 2/ emissions were measured by gas chromatography and dissolved organic carbon, NH4 +-N, NO/sub 3/ --N and soil pH were measured during incubation study. Addition of lime to acidic soil significantly increased the concentration of DOC and N mineralization rate. Higher concentrations of DOC and N mineralization, consequently, increased the CO/sub 2/ emissions from lime treated soils. Cumulative CO/sub 2/ emission was 75% and 71% higher from L and H treatments as compared to CK. The results of current study suggest that DOC and N mineralization are critical in controlling gaseous emissions of CO/sub 2/ from acidic soils following lime application. (author)

  9. Bacterial diversity and composition in major fresh produce growing soils affected by physiochemical properties and geographic locations.

    Science.gov (United States)

    Ma, Jincai; Ibekwe, A Mark; Yang, Ching-Hong; Crowley, David E

    2016-09-01

    Microbial diversity of agricultural soils has been well documented, but information on leafy green producing soils is limited. In this study, we investigated microbial diversity and community structures in 32 (16 organic, 16 conventionally managed soils) from California (CA) and Arizona (AZ) using pyrosequencing, and identified factors affecting bacterial composition. Results of detrended correspondence analysis (DCA) and dissimilarity analysis showed that bacterial community structures of conventionally managed soils were similar to that of organically managed soils; while the bacterial community structures in soils from Salinas, California were different (Psoils from Yuma, Arizona and Imperial Valley, California. Canonical correspondence analysis (CCA) and artificial neural network (ANN) analysis of bacterial community structures and soil variables showed that electrical conductivity (EC), clay content, water-holding capacity (WHC), pH, total nitrogen (TN), and organic carbon (OC) significantly (Psoil physical properties (clay, EC, and WHC), soil chemical variables (pH, TN, and OC) and sampling location explained 16.3%, 12.5%, and 50.9%, respectively, of total variations in bacterial community structure, leaving 13% of the total variation unexplained. Our current study showed that bacterial community composition and diversity in major fresh produce growing soils from California and Arizona is a function of soil physiochemical characteristics and geographic distances of sampling sites. PMID:27135583

  10. potencialmente repelentes à fauna consumidora

    Directory of Open Access Journals (Sweden)

    Guilherme O. S. Ferraz de Arruda

    2007-01-01

    Full Text Available The seed of Araucaria angustifolia, “pinhão”, is becoming a alternative way of income for many families living at south and southeast of Brazil. The intensive attack on Paraná pine seeds by the wild fauna, that occur at newly-planted areas by direct sowing and at nursery of seedlings, is one of several adverses and distimulating factors to specie spreading. The objective of this work was to verify probable phytotoxics effects of some naturals and synthetics substances potentially repellentes to wild fauna, in Araucaria angustifolia seeds “in vitro”. The experiment was realized at Phytopatology and Plant Physiology Laboratory of Center of Agroveterinary Sciences, University of Santa Catarina State – Brazil, from june to december, 2004. The Paraná pine seeds, after preparation and treatment with vegetal and not vegetal substances, were sown in plastic trays with vermiculite substratum and put on cabin of growth with controlled temperature, relative humidity of air, humidity of substratum and photoperiods. It was adopted the randomized complete design with 15 treatments, with 10 seeds each treatment and with 4 repetitions. The tested substances separately or in mixtures were: extract of fruit of red pepper, root of parsley, stem and leaf of wormwood herb, lemon scented gum essential oil, linseed oil, castor bean oil, rosin, copper oxychloride, copper sulphate, sulphur and látex ink. The root emission, stem emission, length of main root and length of stem were evaluated 76 days after sowing and statisticaly analyzed. The analysis make possible to conclude that the tested extract do not have phytotoxic effect on seeds and that the substances tested “in vitro” can be used in field experiments, in repellence traits for Parana pine seeds consuming fauna. Keywords: effects fitotóxicos; pine seeds of Araucaria angustifolia; predação of seeds.

  11. La fauna de la Orinoquia

    OpenAIRE

    THOMAS R. DEFLER

    1998-01-01

    La típica fauna orinoquense, está representada en la literatura y la tradición por los animales que han sido más evidentes al ojo o al oído humanos, o los que con mayor frecuencia figuran en los cuentos, leyendas y temores de la gente, o aquellos que son el blanco más frecuente de. la caza para consumo. Los más conocidos y fácilmente observados en los Llanos Orientales incluyen el venado sabanero |(Odocoileusvirginianus), el chigüiro(Hydróchaeris hydrochaeris), y la corocora roja |(Eudo...

  12. Fauna Europaea: Helminths (Animal Parasitic

    Directory of Open Access Journals (Sweden)

    David Gibson

    2014-09-01

    Full Text Available Fauna Europaea provides a public web-service with an index of scientific names (including important synonyms of all living European land and freshwater animals, their geographical distribution at country level (up to the Urals, excluding the Caucasus region, and some additional information. The Fauna Europaea project covers about 230,000 taxonomic names, including 130,000 accepted species and 14,000 accepted subspecies, which is much more than the originally projected number of 100,000 species. This represents a huge effort by more than 400 contributing specialists throughout Europe and is a unique (standard reference suitable for many users in science, government, industry, nature conservation and education. Helminths parasitic in animals represent a large assemblage of worms, representing three phyla, with more than 200 families and almost 4,000 species of parasites from all major vertebrate and many invertebrate groups. A general introduction is given for each of the major groups of parasitic worms, i.e. the Acanthocephala, Monogenea, Trematoda (Aspidogastrea and Digenea, Cestoda and Nematoda. Basic information for each group includes its size, host-range, distribution, morphological features, life-cycle, classification, identification and recent key-works. Tabulations include a complete list of families dealt with, the number of species in each and the name of the specialist responsible for data acquisition, a list of additional specialists who helped with particular groups, and a list of higher taxa dealt with down to the family level. A compilation of useful references is appended.

  13. Performance of neutron scattering relative to Diviner2000 for estimating soil water content in salt affected soils

    International Nuclear Information System (INIS)

    A field experiment was conducted on sandy clay and clayey soils at Deir Ezzor to compare the performance of Neutron Scattering (NS) relative to a capacitance probe (CP), Diviner2000, in our local conditions under saline soils. The effect of soil electrical conductivity (ECe) and bulk density (ρb) on the precession, accuracy and sensitivity of the tested equipment s were evaluated. Also, the ability to improve the calibration equation for these equipment s, by including ECe and ρb as independent variables in the equation formula, was studied. The study showed that, Diviner2000 was very sensitive to soil bulk density and electrical conductivity of the soil (i.e. soil salinity) compared to the NS. Multiple non-linear regressions improved the fitting when both parameters (ρb and ECe) were included in the equation, even though the correlation coefficient (R2) remained low in the case of Diviner2000.(author)

  14. Zn—Cu Interaction Affecting Zn Adsorption and Plant Availability in a Metal—Contaminated Soil

    Institute of Scientific and Technical Information of China (English)

    D.L.Rimmer; LuoYongming

    1996-01-01

    In a previous greenhouse experiment,we showed that there was an interaction between cu and Zn,which affected growth and metal uptake by young barley plants grown on soil to which Cd,Cu,Pb,and Zn had been added.We suggested that the underlying mechanism was the control of the amount of plant-available Zn by competitive adsorption between Cu and Zn,In order to test this hypothesis,the adsorption of Zn alone,and in the presence of added Cd,Cu and Pb,has been measured using the same soil.Following adsorption,the extractability of the Zn in CaCl2 solution was measured .The adsorption isotherms showed that of the added metals only Cu had a large effect on Zn adsorption.The effect of Cu was to reduce Zn adsoption and to increase the amount of CaCl2-extractable(i.e.plant-available) Zn,in agreement with the conclusions from the greenhouse experiment.The magnitude of the effect of Cu on plant-avalilable Zn was similar in both experiments.

  15. Sonoran Desert winter annuals affected by density of red brome and soil nitrogen

    Science.gov (United States)

    Salo, L.F.; McPherson, G.R.; Williams, D.G.

    2005-01-01

    Red brome [Bromus madritensis subsp. rubens (L.) Husn.] is a Mediterranean winter annual grass that has invaded Southwestern USA deserts. This study evaluated interactions among 13 Sonoran Desert annual species at four densities of red brome from 0 to the equivalent of 1200 plants ma??2. We examined these interactions at low (3 I?g) and high (537 I?g NO3a?? g soila??1) nitrogen (N) to evaluate the relative effects of soil N level on survival and growth of native annuals and red brome. Red brome did not affect emergence or survival of native annuals, but significantly reduced growth of natives, raising concerns about effects of this exotic grass on the fecundity of these species. Differences in growth of red brome and of the three dominant non nitrogen-fixing native annuals at the two levels of soil N were similar. Total species biomass of red brome was reduced by 83% at low, compared to high, N levels, whereas that of the three native species was reduced by from 42 to 95%. Mean individual biomass of red brome was reduced by 87% at low, compared to high, N levels, whereas that of the three native species was reduced by from 72 to 89%.

  16. How do changes in bulk soil organic carbon content affect carbon concentrations in individual soil particle fractions?

    Science.gov (United States)

    Yang, X M; Drury, C F; Reynolds, W D; Yang, J Y

    2016-01-01

    We test the common assumption that organic carbon (OC) storage occurs on sand-sized soil particles only after the OC storage capacity on silt- and clay-sized particles is saturated. Soil samples from a Brookston clay loam in Southwestern Ontario were analysed for the OC concentrations in bulk soil, and on the clay (<2 μm), silt (2-53 μm) and sand (53-2000 μm) particle size fractions. The OC concentrations in bulk soil ranged from 4.7 to 70.8 g C kg(-1) soil. The OC concentrations on all three particle size fractions were significantly related to the OC concentration of bulk soil. However, OC concentration increased slowly toward an apparent maximum on silt and clay, but this maximum was far greater than the maximum predicted by established C sequestration models. In addition, significant increases in OC associated with sand occurred when the bulk soil OC concentration exceeded 30 g C kg(-1), but this increase occurred when the OC concentration on silt + clay was still far below the predicted storage capacity for silt and clay fractions. Since the OC concentrations in all fractions of Brookston clay loam soil continued to increase with increasing C (bulk soil OC content) input, we concluded that the concept of OC storage capacity requires further investigation. PMID:27251365

  17. Soil aggregate stability as affected by clay mineralogy and polyacrylamide addition

    Science.gov (United States)

    The addition of polyacrylamide (PAM) to soil leads to stabilization of existing aggregates and improved bonding between, and aggregation of adjacent soil particles However, the dependence of PAM efficacy as an aggregate stabilizing agent on soil-clay mineralogy has not been studied. Sixteen soil sam...

  18. Use of advanced information technologies for water conservation on salt-affected soils

    Science.gov (United States)

    Water conservation on arid and semi-arid soils must be done with constant and careful consideration of the distribution of salinity across the landscape and through the soil profile. Soil salinity can be managed through leaching and the application of various soil amendments. The field-scale manag...

  19. Initial water repellency affected organic matter depletion rates of manure amended soils in Sri Lanka

    OpenAIRE

    Leelamanie, D.A.L.

    2014-01-01

    The wetting rate of soil is a measure of water repellency, which is a property of soils that prevents water from wetting or penetrating into dry soil. The objective of the present research was to examine the initial water repellency of organic manure amended soil, and its relation to the soil organic matter (SOM) depletion rates in the laboratory. Soil collected from the Wilpita natural forest, Sri Lanka, was mixed with organic manure to prepare soil samples with 0, 5, 10, 25, and 50% organic...

  20. Black north against white south: The comparison of biodiversity patterns between the European and Antarctic rotifer soil communities suggest the potential vulnerability of micrometazoan fauna in the White Continent

    Czech Academy of Sciences Publication Activity Database

    Iakovenko, N.; Smykla, J.; Janko, Karel; Emslie, S.D.; Devetter, Miloslav

    České Budějovice : Institute of Soil Biology, BC ASCR, 2011. s. 28. ISBN 978-80-86525-19-8. [Central European Workshop on Soil Zoology /11./. 11.04.2011-14.04.2011, České Budějovice] Institutional research plan: CEZ:AV0Z60660521; CEZ:AV0Z50450515 Keywords : biodiversity * European rotifer soil communities * Antarctic rotifer soil communities Subject RIV: EH - Ecology, Behaviour

  1. Spatial Analysis of Soil and Water Quality in Tsunami AffectedAreas of Nagapattinam District, Tamilnadu, India

    Directory of Open Access Journals (Sweden)

    M. Velayudha Das

    2014-09-01

    Full Text Available In India, the natural disasters, especially the Tsunami in 2004 having exposed our unpreparedness, variability, diverse scientific, engineering, financial and also social processes. Vedaranyamtalukof Nagapattinam coastal region of Tamilnadu, India,was severely affected by Tsunami-2004. Due to its unique geological nature and climate conditions, the quality of soil and water resources was subjected to natural and synthetic changes. The recent efforts of prawn culture and saltpan in these areas also affect the natural resources. This study has revealed the present scenario of soil and water resources by analyzing their chemical parameters in the Tsunami affected areas after ten years of Tsunami-2004. For this study, soil samples (less than 30cm depth from land surface and groundwater samples (from existing hand/bore pumps were collected in the study area. It was observed from the analysis that the pH of soil was improved well and EC was lowered significantly except few places. Regarding the available N, P, K of soil, N was low, P and Kwere low to medium range. Further thepH,DO, Turbidity, Hardness,Cl and Mgof groundwater were within the permissible limit;EC and TDS were slight to moderate range for irrigation and drinking.The SAR is within the maximum allowable limit which inferred that groundwater can be used for irrigation without any risk.Thisspatial-temporal variability of soil and water parameters were mapped in GIS environment (Surfer ver. 9 and compared with pretsunami-2004 as well as ground truth scenario. Keeping these results, the soil is suitable for agriculture production. The natural flash flood has helped to reduce contamination of soil and water due to Tsunami-2004. However,due to alkaline in nature the quality of groundwater is not fit for drinking in some places but suitable for irrigation. Among the affected villages, Vedaranyam village has worst quality. This study also recommends suitable management strategies for sustainable

  2. Factors Affecting Spatial Variation of Annual Apparent Q10 of Soil Respiration in Two Warm Temperate Forests

    OpenAIRE

    Luan, Junwei; Liu, Shirong; Wang, Jingxin; Zhu, Xueling

    2013-01-01

    A range of factors has been identified that affect the temperature sensitivity (Q10 values) of the soil-to-atmosphere CO2 flux. However, the factors influencing the spatial distribution of Q10 values within warm temperate forests are poorly understood. In this study, we examined the spatial variation of Q10 values and its controlling factors in both a naturally regenerated oak forest (OF) and a pine plantation (PP). Q10 values were determined based on monthly soil respiration (RS) measurement...

  3. Plant material as bioaccumulator of arsenic in soils affected by mining activities

    Science.gov (United States)

    Martínez-López, Salvadora; Martínez-Sánchez, Maria Jose; García-Lorenzo, Maria Luz; Pérez-Sirvent, Carmen

    2010-05-01

    arsenic extracted by HCl, with the oxidizable-organic matter and sulfides fraction and with the arsenic extracted by Mehra-Jackson extraction. According to our results, As is accumulated in the leaves of the plants and is linked with iron oxides of these soils affected by mining activities.

  4. Environmental Factors Affect Acidobacterial Communities below the Subgroup Level in Grassland and Forest Soils

    OpenAIRE

    Naether, A.; Foesel, B.; Naegele, V.; Wuest, P.; Weinert, J.; Bonkowski, M.; Alt, F; Y. Oelmann; Polle, A.; Lohaus, G.; Gockel, S.; Hemp, A.; Kalko, E.; Linsenmair, K.; Pfeiffer, S

    2012-01-01

    In soil, Acidobacteria constitute on average 20% of all bacteria, are highly diverse, and are physiologically active in situ. However, their individual functions and interactions with higher taxa in soil are still unknown. Here, potential effects of land use, soil properties, plant diversity, and soil nanofauna on acidobacterial community composition were studied by cultivation-independent methods in grassland and forest soils from three different regions in Germany. The analysis of 16S rRNA ...

  5. Conventional and organic soil fertility management practices affect corn plant nutrition and Ostrinia nubilalis (Lepidoptera: Crambidae) larval performance.

    Science.gov (United States)

    Murrell, Ebony G; Cullen, Eileen M

    2014-10-01

    Few studies compare how different soil fertilization practices affect plant mineral content and insect performance in organic systems. This study examined: 1) The European corn borer, Ostrinia nubilalis (Hübner), larval response on corn (Zea mays L.) grown in field soils with different soil management histories; and 2) resilience of these plants to O. nubilalis herbivory. Treatments included: 1) standard organic--organically managed soil fertilized with dairy manure and 2 yr of alfalfa (Medicago sativa L.) in the rotation; 2) basic cation saturation ratio--organically managed soil fertilized with dairy manure and alfalfa nitrogen credits, plus addition of gypsum (CaSO4·2H2O) according to the soil balance hypothesis; and 3) conventional--conventionally managed soil fertilized with synthetic fertilizers. Corn plants were reared to maturity in a greenhouse, and then infested with 0-40 O. nubilalis larvae for 17 d. O. nubilalis exhibited negative competitive response to increasing larval densities. Mean development time was significantly faster for larvae consuming basic cation saturation ratio plants than those on standard organic plants, with intermediate development time on conventional plants. Neither total yield (number of kernels) nor proportion kernels damaged differed among soil fertility treatments. Soil nutrients differed significantly in S and in Ca:Mg and Ca:K ratios, but principal components analysis of plant tissue samples taken before O. nubilalis infestation showed that S, Fe, and Cu contributed most to differences in plant nutrient profiles among soil fertility treatments. Results demonstrate that different fertilization regimens can significantly affect insect performance within the context of organic systems, but the effects in this study were relatively minor compared with effects of intraspecific competition. PMID:25203485

  6. Physicochemical and biological quality of soil in hexavalent chromium-contaminated soils as affected by chemical and microbial remediation.

    Science.gov (United States)

    Liao, Yingping; Min, Xiaobo; Yang, Zhihui; Chai, Liyuan; Zhang, Shujuan; Wang, Yangyang

    2014-01-01

    Chemical and microbial methods are the main remediation technologies for chromium-contaminated soil. These technologies have progressed rapidly in recent years; however, there is still a lack of methods for evaluating the chemical and biological quality of soil after different remediation technologies have been applied. In this paper, microbial remediation with indigenous bacteria and chemical remediation with ferrous sulphate were used for the remediation of soils contaminated with Cr(VI) at two levels (80 and 1,276 mg kg(-1)) through a column leaching experiment. After microbial remediation with indigenous bacteria, the average concentration of water-soluble Cr(VI) in the soils was reduced to less than 5.0 mg kg(-1). Soil quality was evaluated based on 11 soil properties and the fuzzy comprehensive assessment method, including fuzzy mathematics and correlative analysis. The chemical fertility quality index was improved by one grade using microbial remediation with indigenous bacteria, and the biological fertility quality index increased by at least a factor of 6. Chemical remediation with ferrous sulphate, however, resulted in lower levels of available phosphorus, dehydrogenase, catalase and polyphenol oxidase. The result showed that microbial remediation with indigenous bacteria was more effective for remedying Cr(VI)-contaminated soils with high pH value than chemical remediation with ferrous sulphate. In addition, the fuzzy comprehensive evaluation method was proven to be a useful tool for monitoring the quality change in chromium-contaminated soils. PMID:23784058

  7. Bioaccessibility of trace elements as affected by soil parameters in smelter-contaminated agricultural soils: A statistical modeling approach

    International Nuclear Information System (INIS)

    An investigation was undertaken to identify the most significant soil parameters that can be used to predict Cd, Pb, and Zn bioaccessibility in smelter-contaminated agricultural soils. A robust model was established from an extended database of soils by using: (i) a training set of 280 samples to select the main soil parameters, to define the best population to be taken into account for the model elaboration, and to construct multivariate regression models, and (ii) a test set of 110 samples to validate the ability of the regression models. Total carbonate, organic matter, sand, P2O5, free Fe–Mn oxide, and pseudototal Al and trace element (TE) contents appeared as the main variables governing TE bioaccessibility. The statistical modeling approach was reasonably successful, indicating that the main soil factors influencing the bioaccessibility of TEs were taken into account and the predictions could be applicable for further risk evaluation in the studied area. - Highlights: ► We model the effects of varying soil parameters on TE bioaccessibility. ► Model calibration and validation were conducted on a test set of 390 soil samples. ► The use of an extended database is needed to elaborate a robust model. ► The bioaccessibility predictions could be applicable for further risk evaluation. - This study supports the hypothesis that the use of an extended database is needed to elaborate a robust model predicting the TE bioaccessibility in the studied soils.

  8. The Effects of Farmyard Manure and Mulch on Soil Physical Properties in a Reclaimed Coastal Tidal Flat Salt-Affected Soil

    Institute of Scientific and Technical Information of China (English)

    ZHANG Jian-bing; YANG Jing-song; YAO Rong-jiang; YU Shi-peng; LI Fu-rong; HOU Xiao-jing

    2014-01-01

    Careful soil management is important for the soil quality and productivity improvement of the reclaimed coastal tidal lfat saline land in northern Jiangsu Province, China. Farmyard manure (FYM) and mulch applications, which affect soil characteristics and plant signiifcantly, are regard as an effective pattern of saline land improvement. As a conventional management in the study region, FYM and mulch are used for the amendment of the new reclaimed tidal lfat regularly, but little is known about their effects on soil physical properties functioning. A study was conducted on a typical coastal tidal lfat saline land, which was reclaimed in 2005, to evaluate the effects of FYM, polyethylene iflm mulch (PM), straw mulch (SM), FYM combined with PM (FYM+PM), FYM combined with SM (FYM+SM), on soil hydraulic properties and soil mechanical impedance. CK represented conventional cultivation in study area without FYM and mulch application and served as a control. The experiment, laid out in a randomized complete block design with three replications, was studied in Huanghaiyuan Farm, which specialized in the agricultural utilization for coastal tidal lfat. Result showed that capillary water holding capacity (CHC), saturated water content (SWC), saturated hydraulic conductivity (Ks) and bulk density (BD), cone index (CI) were affected signiifcantly by the FYM and mulch application, especially in the 0-10 cm soil layer. FYM and mulch management increased CHC, SWC and Ks over all soil depth in the order of FYM+SM>FYM+PM>FYM>SM>PM>CK. With the contrary sequence, BD and CI decreased signiifcantly;however, FYM and mulch application affected BD and CI only in the upper soil layers. CHC, SWC and Ks decreased signiifcantly with the increasing of soil depth, BD and CI, and a signiifcant liner equation was found between CHC, SWC, Ks and BD, CI. With the highest CHC (38.15%), SWC (39.55%), Ks (6.00 mm h-1) and the lowest BD (1.26 g cm-3) and CI (2.71 MPa), the combined management of FYM

  9. Soil organic carbon fractions in a Vertisol under irrigated cotton production as affected by burning and incorporating cotton stubble

    International Nuclear Information System (INIS)

    The contribution of cotton stubble to the soil organic matter content of Vertisols under cotton production is not well understood. A 3-year experiment was conducted at the Australian Cotton Research Institute to study the effects of burning and incorporating cotton stubble on the recovery of fertiliser nitrogen (N), lint yield, and organic matter levels. This study reports on the changes in soil organic matter fractions as affected by burning and incorporating cotton stubble into the soil. Soil samples collected at the start and end of the 3-year experiment were analysed for total carbon (CT), total N (NT), and δ13C (a measure of 13C/12C isotopic ratios). Labile carbon (CL) was determined by ease of oxidation and non-labile carbon (CNL) was calculated as the difference between CT and CL. Based on the changes in CT, CL, and CNL, a carbon management index (CMI) was calculated. Further analyses were made for total polysaccharides (PT), labile polysaccharides (PL), and light fraction C (LF-C). Stubble management did not significantly affect the NT content of the soil. After 3 years, the stubble-incorporated plots had a significantly higher content of CT, CL, and polysaccharides. Incorporation of stubble into the soil increased the CMI by 41%, whereas burning decreased the CMI by 6%. The amount of LF-C obtained after 3 years in the stubble-incorporated soil was almost double that obtained in the stubble-burnt soil. It was concluded that for sustainable management of soil organic matter in the Vertisols used for cotton production, stubble produced in the system should be incorporated instead of burnt. Copyright (1998) CSIRO Publishing

  10. Does S-metolachlor affect the performance of Pseudomonas sp. strain ADP as bioaugmentation bacterium for atrazine-contaminated soils?

    Directory of Open Access Journals (Sweden)

    Cristina A Viegas

    Full Text Available Atrazine (ATZ and S-metolachlor (S-MET are two herbicides widely used, often as mixtures. The present work examined whether the presence of S-MET affects the ATZ-biodegradation activity of the bioaugmentation bacterium Pseudomonas sp. strain ADP in a crop soil. S-MET concentrations were selected for their relevance in worst-case scenarios of soil contamination by a commercial formulation containing both herbicides. At concentrations representative of application of high doses of the formulation (up to 50 µg g(-1 of soil, corresponding to a dose approximately 50× higher than the recommended field dose (RD, the presence of pure S-MET significantly affected neither bacteria survival (~10(7 initial viable cells g(-1 of soil nor its ATZ-mineralization activity. Consistently, biodegradation experiments, in larger soil microcosms spiked with 20× or 50 × RD of the double formulation and inoculated with the bacterium, revealed ATZ to be rapidly (in up to 5 days and extensively (>96% removed from the soil. During the 5 days, concentration of S-MET decreased moderately to about 60% of the initial, both in inoculated and non-inoculated microcosms. Concomitantly, an accumulation of the two metabolites S-MET ethanesulfonic acid and S-MET oxanilic acid was found. Despite the dissipation of almost all the ATZ from the treated soils, the respective eluates were still highly toxic to an aquatic microalgae species, being as toxic as those from the untreated soil. We suggest that this high toxicity may be due to the S-MET and/or its metabolites remaining in the soil.

  11. Transport of copper as affected by titania nanoparticles in soil columns

    International Nuclear Information System (INIS)

    The effects of TiO2 nanoparticles on the transport of Cu through four different soil columns were studied. For two soils (HB and DX), TiO2 nanoparticles acted as a Cu carrier and facilitated the transport of Cu. For a third soil (BJ) TiO2 nanoparticles also facilitated Cu transport but to a much lesser degree, but for a fourth soil (HLJ) TiO2 nanoparticles retarded the transport of Cu. Linear correlation analysis indicated that soil properties rather than sorption capacities for Cu primary governed whether TiO2 nanoparticles-facilitated Cu transport. The TiO2-associated Cu of outflow in the Cu-contaminated soil columns was significantly positively correlated with soil pH and negatively correlated with CEC and DOC. During passage through the soil columns 46.6-99.9% of Cu initially adsorbed onto TiO2 could be 'stripped' from nanoparticles depending on soil, where Cu desorption from TiO2 nanoparticles increased with decreasing flow velocity and soil pH. - Highlights: → TiO2 nanoparticles could facilitate or retard the transport of Cu in soils. → Soil properties primarily governed TiO2-facilitated Cu transport. → Cu initially adsorbed onto TiO2 could be 'stripped' duing transport. - TiO2 nanoparticles play an important role in mediating and transporting Cu in soil columns.

  12. Wheat Growth and Photosynthesis as Affected by Oxytetracycline as a Soil Contaminant

    Institute of Scientific and Technical Information of China (English)

    LI Zhao-Jun; XIE Xiao-Yu; ZHANG Shu-Qing; LIANG Yong-Chao

    2011-01-01

    Extensive worldwide use of oxytetracycline (OTC), a member of the tetracyclines, has resulted in its accumulation in soils, posing a potential risk to food production and safety. A pair of OTC-sensitive (Heyou 1) and OTC-tolerant (Yannong 21) wheat (Triticum aestivum L.) cultivars was compared hydroponically at 0.01, 0.02, 0.04, and 0.08 mmol L-1 OTC in terms of wheat growth and photosynthesis. Biomass and shoot length decreased significantly with the addition of OTC, with the decreases in dry biomass and shoot length being 5.61%-13.75% and 3.33%-8.57% larger, respectively, for Heyou 1 than Yannong 21. Photosynthesis of Heyou 1 was suppressed by OTC as indicated by the significant decreases in photosynthetic rate (PN), transpiration rate (TR), and stomatal conductance (GS) and the significant increase in intercellular CO2 concentrations (CI), at all OTC levels. Stomatal limitation (LS)and water use efficiencies (WUE) of Heyou 1 also increased significantly, but not at 0.08 mmol L-1 OTC. However, photosynthesis of Yannong 21 was suppressed by OTC only at high OTC levels from 0.02 to 0.08 mmol L- 1 as indicated by the decreases in PN, GS,TR, and LS; at 0.01 mmol L-1 OTC, PN, CI, GS, and TR significantly increased. It was noted that WUE of Yannong 21 was not affected by OTC addition. The results from this hydroponic test suggested that OTC had a potential risk to crop growth through inhibition of photosynthesis, requiring further confirmation with soil tests.

  13. Assemblages of earthworms and collembolans in fen soil as affected by landslide

    Czech Academy of Sciences Publication Activity Database

    Sterzyńska, M.; Nicia, P.; Pižl, Václav

    Coimbra : University of Coimbra, 2012. s. 30. [International Colloquium on Soil Zoology /16./. 06.08.2012-10.08.2012, Coimbra] Institutional support: RVO:60077344 Keywords : earthworms * collembolans * fen soil * landslide Subject RIV: EH - Ecology, Behaviour

  14. DICKINSARTELLA FAUNA FROM THE SAIWAN FORMATION (OMAN: A BIVALVE FAUNA TESTIFYING TO THE LATE SAKMARIAN (EARLY PERMIAN CLIMATIC AMELIORATION ALONG THE NORTH-EASTERN GONDWANAN FRINGE.

    Directory of Open Access Journals (Sweden)

    CRISTIANO LARGHI

    2005-11-01

    Dickinsartella Fauna and confirms the correlation between Arabian and Australian series already remarked by previous authors. The "Dickinsartella fauna" is the first bivalve fauna testifying to the climatic amelioration gradually affecting the North-Eastern Gondwanan fringe at the end of the Early Permian glacial events. This pioneer fauna spread out, probably in a cool-temperate climate, on the substrate provided by the mid-Sakmarian (basal Sterlitamakian transgression, connected with the final stages of the Gondwanan deglaciation and/or with initial sea-floor spreading in the Neotethys. In the present paper some remarks on the autecology of the new species from the "Pachycyrtella bed" are also discussed.

  15. Organic amendments affecting sorption, leaching and dissipation of fungicides in soils.

    Science.gov (United States)

    Fernandes, María C; Cox, Lucía; Hermosín, María C; Cornejo, Juan

    2006-12-01

    Metalaxyl and tricyclazole are two fungicides widely used in Spain in vineyard and rice crops respectively. In this study an investigation has been made of the effect of three organic amendments [two commercial amendments, solid fertiormont (SF) and liquid fertiormont (LF), and a residue from the olive oil production industry, alperujo (OW)] on fungicide fate in soils. Changes in soil porosity on amendment were studied by mercury intrusion porosimetry, sorption-desorption studies were performed by the batch equilibration method, dissipation of metalaxyl and tricyclazole in the soil was studied at - 33 kPa moisture content and 20 degrees C and leaching was studied in hand-packed soil columns. Amendments with SF and LF reduced soil porosity, while OW increased porosity through an increase in pore volume in the highest range studied. Tricyclazole sorbed to soils to a much higher extent than metalaxyl. With some exceptions, sorption of both fungicides increased on amendment, especially in the case of SF-amended soils, which rendered the highest K(oc) values. In soils amended with the liquid amendment LF, sorption either remained unaffected or decreased, and this decrease was much higher in the case of metalaxyl and a soil with 70% clay. In this clay soil, amendment with OW, of very high soluble organic matter content, also decreased metalaxyl sorption. Tricyclazole is more persistent in soil than metalaxyl, and both fungicides were found to be more persistent in amended soils than in unamended soils. Leaching of metalaxyl and tricyclazole in soil columns was inversely related to sorption capacity. The low recoveries of tricyclazole in leachates and in soil columns when compared with metalaxyl, a less persistent fungicide, were attributed to diffusion into micropores and to increase in sorption with residence time in the soil, both processes favoured by the low mobility of tricyclazole. PMID:17051652

  16. Soil acidity as affecting micronutrients concentration, nitrato reductase enzyme activity and yield in upland rice plants

    OpenAIRE

    Edemar Moro; Carlos Alexandre Costa Crusciol; Heitor Cantarella; Adriano Stephan Nascente; Adriana Lima Moro; Fernando Broetto

    2013-01-01

    The lowest grain yield of rice under no-tillage system (NTS) in relation to the conventional system may be due to the predominance nitrate in the soil and the low nitrate reductase activity. Another reason may be caused by micronutrient deficiency because of superficially soil acidity corrections. Therefore, the objective of this study was to evaluate the changes caused by soil pH in the N forms in the soil, micronutrients concentration in rice plants, nitrate reductase activity, yield of ric...

  17. Structural stability of exposed gully wall in Central Eastern Nigeria as affected by soil properties

    OpenAIRE

    N. Ejiofor; C. A. Igwe

    2005-01-01

    We studied the soil stability of a gully wall in a gully erosion prone area of Central Eastern Nigeria. The objective was to investigate the physicochemical properties of the gully wall soils and to relate them to the collapsing and stability of the gullies. Ten soil layers were sampled for analysis. The bulk density was high while the saturated hydraulic conductivity (Ks) was moderately high resulting in rapid permeability for the soil layers. The liquid limits (LL) and plastic limits (PL) w...

  18. Soil sterilization affects aging-related sequestration and bioavailability of p,p'-DDE and anthracene to earthworms

    International Nuclear Information System (INIS)

    Laboratory experiments investigated the effects of soil sterilization and compound aging on the bioaccumulation of spiked p,p'-DDE and anthracene by Eisenia fetida and Lumbricus terrestris. Declines in bioavailability occurred as pollutant residence time in both sterile and non-sterile soils increased from 3 to 203 d. Accumulation was generally higher in sterile soils during initial periods of aging (from 3-103 d). By 203 d, however, bioavailability of the compounds was unaffected by sterilization. Gamma irradiation and autoclaving may have altered bioavailability by inducing changes in the chemistry of soil organic matter (SOM). The results support a dual-mode partitioning sorption model in which the SOM components associated with short-term sorption (the 'soft' or 'rubbery' phases) are more affected than are the components associated with long-term sorption (the 'glassy' or microcrystalline phases). Risk assessments based on data from experiments in which sterile soil was used could overestimate exposure and bioaccumulation of pollutants. - Soil sterilization affects aging-related sequestration of organic contaminants.

  19. Soil organic matter in fire-affected pastures and in an Araucaria forest in South-Brazilian Leptosols

    Directory of Open Access Journals (Sweden)

    Mariana da Luz Potes

    2012-05-01

    Full Text Available The objective of this work was to evaluate the distribution pattern and composition of soil organic matter (SOM and its physical pools of Leptosols periodically affected by fire over the last 100 years in South Brazil. Soil samples at 0-5, 5-10, and 10-15 cm depths were collected from the following environments: native pasture without burning in the last year and grazed with 0.5 livestock per hectare per year (1NB; native pasture without burning in the last 23 years and grazed with 2.0 livestock per hectare per year (23NB; and an Araucaria forest (AF. Physical fractionation was performed with the 0-5 and 5-10 cm soil layers. Soil C and N stocks were determined in the three depths and in the physical pools, and organic matter was characterized by infrared spectroscopy and thermogravimetry. The largest C stocks in all depths and physical pools were found under the AF. The 23NB environment showed the lowest soil C and N stocks at the 5-15 cm depth, which was related to the end of burning and to the higher grazing intensity. The SOM of the occluded light fraction showed a greater chemical recalcitrance in 1NB than in 23NB. Annual pasture burning does not affect soil C stocks up to 15 cm of depth.

  20. Integrated Effects of Wheat Residue and Phosphorus Application on Rice Productivity and Soil Health Under Salt Affected Soils

    International Nuclear Information System (INIS)

    A field experiment was conducted to determine the effect of crop residue incorporation along with P application on rice production under salt affected soil having pH 8.57, ECe 5.65 (dS/m), SAR 17.38 (mmol/L)percentage and available P (3.9 mg/kg). The study was carried out at MK Farm, Farooqabad, Sheikhupura, Pakistan during Kharif season in 2009. Treatments were arranged using randomised complete block design (RCBD) with three replications. The treatments were control (T/sub 1/), straw incorporation @ 5 tonnes/ha (T/sub 2/), T/sub 2/+20 kg/ P2O5/ha (T/sub 3/), T/sub 2/+40 kg/P2O5/ha (T/sub 4/) and T/sbu 2/+60 kg/P/sub 2/O/sub 5//ha (T/sub 5/). The highest grain yield (4.407 t/ha) was recorded in treatment receiving 5 tonnes wheat straw along with 40 kg P/sub 2/O/sub 5//ha which is 14.6percentage more than control and the lowest grain yield (3.847 t/ha) was recorded in control. Maximum P (0.37percentage) and K(0.13percentage) contents of grain were recorded where wheat straw was applied @ 5 t/ha along with 40 and 60 kg P/sub 2/O/sub 5//ha whereby P content of control was (0.3percentage). The residual P was 5.7 mg/kg where wheat straw was applied @ 5 t/ha along with 40 and 60 kg P/sub 2/O/sub 5//ha. The residual P in control was 4.3 mg/kg. It can be concluded that incorporation of residue enhanced the availability of P, K and Ca to plant roots. Under saline-sodic/sodic conditions, plant can better cope with salinity in the presence of calcium and K availability. (author)

  1. Applications of Fertilizer Cations Affect Cadmium and Zinc Concentrations in Soil Solutions and Uptake by Plants

    DEFF Research Database (Denmark)

    Lorenz, S. E.; Hamon, R. E.; McGrath, S. P.; Holm, Peter Engelund; Christensen, Thomas Højlund

    1994-01-01

    A pot experiment was conducted to study changes over time of Cd and Zn in soil solution and in plants. Radish was grown in a soil which had been contaminated with heavy metals prior to 1961. Constant amounts of a fertilizer solution (NH4N03, KN03) were added daily. Soil solution was obtained at i...

  2. Appraisal of biogeochemical markers for the assessment of damage levels in soils affected by wild fires

    OpenAIRE

    González-Vila, Francisco Javier; González-Pérez, José Antonio; Almendros Martín, Gonzalo; Arias Fernández, Mª E.; Knicker, Heike

    2006-01-01

    Comunicación oral SSS22-1TU3O-005 presentada en la sesión Oral Programme - SSS22 Wildfire effects on soil organic carbon dynamics, soil degradation and soil redistribution (co-listed in BG & ERE).-- Congreso, celebrado del 2-7 de abril de 2006, en Viena, Austria.

  3. Organic matter dynamics in a forest soil as affected by climate change.

    NARCIS (Netherlands)

    Verburg, P.S.J.

    1998-01-01

    Large amounts of carbon are stored in boreal soils as soil organic matter. Aim of the research presented in this thesis was to quantify the effects of climate change on decomposition soil organic matter in a boreal forest ecosystem by means of field and laboratory experiments. Field experiments were

  4. Vertical distribution of radiocesium in soils of the area affected by the Fukushima Dai-ichi nuclear power plant accident

    Science.gov (United States)

    Konoplev, A. V.; Golosov, V. N.; Yoschenko, V. I.; Nanba, K.; Onda, Y.; Takase, T.; Wakiyama, Y.

    2016-05-01

    Presented are results of the study of radiocesium vertical distribution in the soils of the irrigation pond catchments in the near field 0.25 to 8 km from the Fukushima Dai-ichi NPP, on sections of the Niida River floodplain, and in a forest ecosystem typical of the territory contaminated after the accident. It is shown that the vertical migration of radiocesium in undisturbed forest and grassland soils in the zone affected by the Fukushima accident is faster than it was in the soils of the 30-km zone of the Chernobyl NPP for a similar time interval after the accident. The effective dispersion coefficients in the Fukushima soils are several times higher than those for the Chernobyl soils. This may be associated with higher annual precipitation (by about 2.5 times) in Fukushima as compared to the Chernobyl zone. In the forest soils the radiocesium dispersion is faster as compared to grassland soils, both in the Fukushima and Chernobyl zones. The study and analysis of the vertical distribution of the Fukushima origin radiocesium in the Niida gawa floodplain soils has made it possible to identify areas of contaminated sediment accumulation on the floodplain. The average accumulation rate for sediments at the study locations on the Niida gawa floodplain varied from 0.3 to 3.3 cm/year. Taking into account the sediments accumulation leading to an increase in the radiocesium inventory in alluvial soils is key for predicting redistribution of radioactive contamination after the Fukushima accident on the river catchments, as well as for decision-making on contaminated territories remediation and clean-up. Clean-up of alluvial soils does not seem to be worthwhile because of the following accumulation of contaminated sediments originating from more contaminated areas, including the exclusion zone.

  5. Trace metal distribution in pristine permafrost-affected soils of the Lena River Delta and its Hinterland, Northern Siberia, Russia

    Directory of Open Access Journals (Sweden)

    I. Antcibor

    2013-02-01

    Full Text Available Soils are an important compartment of ecosystems and have the ability to immobilize chemicals preventing their movement to other environment compartments. Predicted climatic changes together with other anthropogenic influences on Arctic terrestrial environments may affect biogeochemical processes enhancing leaching and migration of trace elements in permafrost-affected soils. This is especially important since the Arctic ecosystems are considered to be very sensitive to climatic changes as well as to chemical contamination. This study characterizes background levels of trace metals in permafrost-affected soils of the Lena River Delta and its hinterland in northern Siberia (73.5° N–69.5° N representing a remote region far from evident anthropogenic trace metal sources. Investigations on total element contents of iron (Fe, arsenic (As, manganese (Mn, zinc (Zn, nickel (Ni, copper (Cu, lead (Pb, cadmium (Cd, cobalt (Co and mercury (Hg in different soil types developed in different geological parent materials have been carried out. The highest concentrations of the majority of the measured elements were observed in soils belonging to ice-rich permafrost sediments formed during the Pleistocene (ice-complex in the Lena River Delta region. Correlation analyses of trace metal concentrations and soil chemical and physical properties at a Holocene estuarine terrace and two modern floodplain levels in the southern-central Lena River Delta (Samoylov Island showed that the main factors controlling the trace metal distribution in these soils are organic matter content, soil texture and contents of iron and manganese-oxides. Principal Component Analysis (PCA revealed that soil oxides play a significant role in trace metal distribution in both top and bottom horizons. Occurrence of organic matter contributes to Cd binding in top soils and Cu binding in bottom horizons. Observed ranges of the background concentrations of the majority of trace elements were

  6. Salvage logging effect on soil properties in a fire-affected Mediterranean forest: a two years monitoring research

    Science.gov (United States)

    Mataix-Solera, Jorge; Moltó, Jorge; Arcenegui, Vicky; García-Orenes, Fuensanta; Chrenkovà, Katerina; Torres, Pilar; Jara-Navarro, Ana B.; Díaz, Gisela; Izquierdo, Ezequiel

    2015-04-01

    In the Mediterranean countries, forest fires are common and must be considered as an ecological factor, but changes in land use, especially in the last five decades have provoked a modification in their natural regime. Moreover, post-fire management can have an additional impact on the ecosystem; in some cases, even more severe than the fire. Salvage logging is a traditional management in most fire-affected areas. In some cases, the way of doing it, using heavy machinery, and the vulnerability of soils to erosion and degradation make this management potentially very agresive to soil, and therefore to the ecosystem. Very little research has been done to study how this treatment could affect soil health. In this research we show 2 years of monitoring of some soil properties in an area affected by a forest fire, where some months later this treatment was applied. The study area is located in 'Sierra de Mariola Natural Park' in Alcoi, Alicante (E Spain). A big forest fire (>500 has) occurred in July 2012. The forest is composed mainly of Pinus halepensis trees with an understory of typical Mediterranean shrubs species such as Quercus coccifera, Rosmarinus officinalis, Thymus vulgaris, Brachypodium retusum, etc. Soil is classified as a Typic Xerorthent (Soil Survey Staff, 2014) developed over marls. In February 2013, salvage logging (SL) treatment consisting in a complete extraction of the burned wood using heavy machinery was applied in a part of the affected forest. Plots for monitoring this effect were installed in this area and in a similar nearby area where no treatment was done, and then used as control (C) for comparison. Soil samplings were done immediately after treatment and every 6 months. Some soil properties were analysed, including soil organic matter (SOM) content, basal soil respiration (BSR), microbial biomass carbon (MBC), bulk density (BD), soil water repellency (SWR), aggregate stability (AS), field capacity, nitrogen, etc. After two years of

  7. Long-term toxicity assessment of soils in a recovered area affected by a mining spill.

    Science.gov (United States)

    Romero-Freire, A; García Fernández, I; Simón Torres, M; Martínez Garzón, F J; Martín Peinado, F J

    2016-01-01

    Residual pollution in the Guadiamar Green Corridor still remains after Aználcollar mine spill in 1998. The polluted areas are identified by the absence of vegetation, soil acidic pH and high concentrations of As, Pb, Zn and Cu. Soil toxicity was assessed by lettuce root elongation and induced soil respiration bioassays. In bare soils, total As and Pb concentrations and water-extractable levels for As, Zn and Cu exceeded the toxicity guidelines. Pollutants responsible for toxicity were different depending on the tested organism, with arsenic being most toxic for lettuce and the metal mixture to soil respiration. Soil properties, such as pH or organic carbon content, are key factors to control metal availability and toxicity in the area. According to our results, there is a risk of pollution to living organisms and the soil quality criteria established in the area should be revised to reduce the risk of toxicity. PMID:26608875

  8. Environmental Factors Affecting Temporal and Spatial Dynamics of Soil Erosion in Xingguo County, South China

    Institute of Scientific and Technical Information of China (English)

    WANG Ku; SHI Xue-Zheng; YU Dong-Sheng; SHI De-Ming; CHEN Jing-Ming; XU Bin-Bin; LIANG Yin; LI De-Cheng

    2005-01-01

    By using soil erosion maps of four different time periods and a digital elevation model (DEM), in combination with the remote sensing and GIS technologies, soil erosion dynamics in Xingguo County of Jiangxi Province in South China were analyzed on both temporal and spatial scales in soils of different parent materials, altitudes and slopes. The results showed that from 1958 to 2000 severe soil erosion was coming under control with a decreasing percentage of the land under severe erosion. It was also found that the soils developed from Quaternary red clay, granite and purple shale were more susceptible to soil erosion and that areas sitting between 200 to 500 m in altitude with a slope less than 3° or between 7° to 20° where human activities were frequent remained to be zones where soil erosion was most likely to occur. These areas deserve special attention in monitoring and controlling.

  9. Urban legacies and soil management affect the concentration and speciation of trace metals in Los Angeles community garden soils.

    Science.gov (United States)

    Clarke, Lorraine Weller; Jenerette, G Darrel; Bain, Daniel J

    2015-02-01

    Heavy metals in urban soils can compromise human health, especially in urban gardens, where gardeners may ingest contaminated dust or crops. To identify patterns of urban garden metal contamination, we measured concentrations and bioavailability of Pb, As, and Cd in soils associated with twelve community gardens in Los Angeles County, CA. This included sequential extractions to partition metals among exchangeable, reducible, organic, or residual fractions. Proximity to road increased all metal concentrations, suggesting vehicle emissions sources. Reducible Pb increased with neighborhood age, suggesting leaded paint as a likely pollutant source. Exchangeable Cd and As both increased with road proximity. Only cultivated soils showed an increase in exchangeable As with road proximity, potentially due to reducing humic acid interactions while Cd bioavailability was mitigated by organic matter. Understanding the geochemical phases and metal bioavailability allows incorporation of contamination patterns into urban planning. PMID:25437835

  10. Sampling Position under No-Tillage System Affects the Results of Soil Physical Properties

    Directory of Open Access Journals (Sweden)

    Camila Jorge Bernabé Ferreira

    2016-01-01

    Full Text Available ABSTRACT Understanding the spatial behavior of soil physical properties under no-tillage system (NT is required for the adoption and maintenance of a sustainable soil management system. The aims of this study were to quantify soil bulk density (BD, porosity in the soil macropore domain (PORp and in the soil matrix domain (PORm, air capacity in the soil matrix (ACm, field capacity (FC, and soil water storage capacity (FC/TP in the row (R, interrow (IR, and intermediate position between R and IR (designated IP in the 0.0-0.10 and 0.10-0.20 m soil layers under NT; and to verify if these soil properties have systematic variation in sampling positions related to rows and interrows of corn. Soil sampling was carried out in transect perpendicular to the corn rows in which 40 sampling points were selected at each position (R, IR, IP and in each soil layer, obtaining undisturbed samples to determine the aforementioned soil physical properties. The influence of sampling position on systematic variation of soil physical properties was evaluated by spectral analysis. In the 0.0-0.1 m layer, tilling the crop rows at the time of planting led to differences in BD, PORp, ACm, FC and FC/TP only in the R position. In the R position, the FC/TP ratio was considered close to ideal (0.66, indicating good water and air availability at this sampling position. The R position also showed BD values lower than the critical bulk density that restricts root growth, suggesting good soil physical conditions for seed germination and plant establishment. Spectral analysis indicated that there was systematic variation in soil physical properties evaluated in the 0.0-0.1 m layer, except for PORm. These results indicated that the soil physical properties evaluated in the 0.0-0.1 m layer were associated with soil position in the rows and interrows of corn. Thus, proper assessment of soil physical properties under NT must take into consideration the sampling positions and previous

  11. Calcareous Sodic Soil Reclamation as Affected by Corn Stalk Application and Incubation:A Laboratory Study

    Institute of Scientific and Technical Information of China (English)

    LI Fa-Hu; R.KEREN

    2009-01-01

    A laboratory lysimeter experiment was conducted to investigate the effects of forage corn (Zea mays L.) stalk application on the CO2 concentration in soil air and calcareous sodic soil reclamation.The experimental treatments tested were soil exchangeable sodium percentage (ESP) levels of 1,11,and 19,added corn stalk contents of 0 to 36 g kg-1,and incubation durations of 30 and 60 days.The experimental results indicated that corn stalk application and incubation significantly increased CO2 partial pressure in soil profile and lowered pH value in soil solution,subsequently increased native CaCO3 mineral dissolution and electrolyte concentration of soil solution,and finally significantly contributed to reduction on soil sodicity level.The reclamation efficiency of calcareous sodic soils increased with the added corn stalk.When corn stalks were added at the rates of 22 and 34 g kg-1 into the soil with initial ESP of 19,its ESP value was decreased by 56% and 78%,respectively,after incubation of 60 days and the leaching of 6.5 pore volumes (about 48 L of percolation water) with distilled water.Therefore,crop stalk application and incubation could be used as a choice to reclaim moderate calcareous sodic soils or as a supplement of phytoremediation to improve reclamation efficiency.

  12. Chemical and Microbiological Parameters of Paddy Soil Quality as Affected by Different Nutrient and Water Regimes

    Institute of Scientific and Technical Information of China (English)

    YANG Chang-Ming; YANG Lin-Zhang; YAN Ting-Mei

    2005-01-01

    A field experiment was conducted from 1999 to 2002 to compare and evaluate the effects of nutrient and water regimes on paddy soil quality by investigating soil chemical and microbiological parameters. Four nutrient regimes, a control, chemical fertilizers only (CF), chemical fertilizers with swine manure (SM), and chemical fertilizers with wheat straw (WS), and two soil moisture regimes, continuous waterlogging (CWL) and alternate wetting and drying (AWD),were investigated. With SM and WS total organic carbon and total nitrogen in the paddy soil were significantly higher (P <0.05) than those with CF. A similar effect for organic amendments was observed in the soil light fraction organic C (LFOC), water-soluble carbohydrates (WSC), and water-soluble organic C (WSOC). CWL, in particular when swine manure was incorporated into the paddy soil, markedly decreased soil redox potential (Eh) and increased total active reducing substances (ARS). Meanwhile, as compared to CF, SM and WS significantly (P < 0.05) increased soil microbial biomass C (MBC) and mineralizable carbon, with differences in AWD being higher than CWL. In addition, SM and WS treatments significantly (P < 0.05) improved rice above-ground biomass and grain yield, with AWD being greater than CWL. Thus, for ecologically sustainable agricultural management of paddy soils, long-term waterlogging should be avoided when organic manure was incorporated into paddy soil.

  13. Structural stability of exposed gully wall in Central Eastern Nigeria as affected by soil properties

    Directory of Open Access Journals (Sweden)

    N. Ejiofor

    2005-09-01

    Full Text Available We studied the soil stability of a gully wall in a gully erosion prone area of Central Eastern Nigeria. The objective was to investigate the physicochemical properties of the gully wall soils and to relate them to the collapsing and stability of the gullies. Ten soil layers were sampled for analysis. The bulk density was high while the saturated hydraulic conductivity (Ks was moderately high resulting in rapid permeability for the soil layers. The liquid limits (LL and plastic limits (PL were low. The water- stable aggregates (WSA were mostly aggregates of <0.50 mm. Such soils with fine aggregate sizes erode more than those with bigger aggregate sizes. Mean-weight diameter (MWD positively correlated significantly with plasticity index but negatively correlated with soil organic matter. Soil properties that related well with the dispersion indices were water-dispersible clay (WDC, moisture at field capacity (FC, permanent wilting point (PWP, available water capacity (AWC, LL and plastic index (PI. The PI, K+, and Ca2+ were the properties which increased aggregation while soil organic matter (SOM which was low in the soil played little or no role in the aggregation of the studied soils.

  14. Nitrate removal and denitrification affected by soil characteristics in nitrate treatment wetlands.

    Science.gov (United States)

    Lin, Ying-Feng; Jing, Shuh-Ren; Lee, Der-Yuan; Chang, Yih-Feng; Shih, Kai-Chung

    2007-03-01

    Several small-scale surface flow constructed wetlands unplanted and planted (monoculture) with various macrophytes (Phragmites australis, Typha orientalis, Pennisetum purpureum, Ipomoea aquatica, and Pistia stratiotes) were established to continuously receive nitrate-contaminated groundwater. Soil characteristics and their effects on nitrate removal and soil denitrification were investigated. The results showed that planted wetland cells exhibited significantly higher (P < 0.05) nitrate removal efficiencies (70-99%) and soil denitrification rates (3.78-15.02 microg N2O-N/g dry soil/h) than an unplanted covered wetland cell (1%, 0.11 microg N2O-N/g/h). However, the unplanted uncovered wetland cell showed a nitrate removal efficiency (55%) lower than but a soil denitrification rate (9.12 microg N2O-N/g/h) comparable to the planted cells. The nitrate removal rate correlated closely and positively with the soil denitrification rate for the planted cells, indicating that soil denitrification is an important process for removing nitrate in constructed wetlands. The results of nitrogen budget revealed that around 68.9-90.7% of the overall nitrogen removal could be attributed to the total denitrification. The soil denitrification rate was found to correlate significantly (P < 0.01) with the extractable organic carbon, organic matter, and in situ-measured redox potential of wetland soil, which accordingly were concluded as suitable indicators of soil denitrification rate and nitrate removal rate in nitrate treatment wetlands. PMID:17365317

  15. Do microorganism stoichiometric alterations affect carbon sequestration in paddy soil subjected to phosphorus input?

    Science.gov (United States)

    Zhang, ZhiJian; Li, HongYi; Hu, Jiao; Li, Xia; He, Qiang; Tian, GuangMing; Wang, Hang; Wang, ShunYao; Wang, Bei

    2015-04-01

    Ecological stoichiometry provides a powerful tool for integrating microbial biomass stoichiometry with ecosystem processes, opening far-reaching possibilities for linking microbial dynamics to soil carbon (C) metabolism in response to agricultural nutrient management. Despite its importance to crop yield, the role of phosphorus (P) with respect to ecological stoichiometry and soil C sequestration in paddy fields remains poorly understood, which limits our ability to predict nutrient-related soil C cycling. Here, we collected soil samples from a paddy field experiment after seven years of superphosphate application along a gradient of 0, 30, 60, and 90 (P-0 through P-90, respectively) kg.ha-1.yr-1 in order to evaluate the role of exogenous P on soil C sequestration through regulating microbial stoichiometry. P fertilization increased soil total organic C and labile organic C by 1-14% and 4-96%, respectively, while rice yield is a function of the activities of soil β-1,4-glucosidase (BG), acid phosphatase (AP), and the level of available soil P through a stepwise linear regression model. P input induced C limitation, as reflected by decreases in the ratios of C:P in soil and microbial biomass. An eco-enzymatic ratio indicating microbial investment in C vs. P acquisition, i.e., ln(BG): ln(AP), changed the ecological function of microbial C acquisition, and was stoichiometrically related to P input. This mechanism drove a shift in soil resource availability by increasing bacterial community richness and diversity, and stimulated soil C sequestration in the paddy field by enhancing C-degradation-related bacteria for the breakdown of plant-derived carbon sources. Therefore, the decline in the C:P stoichiometric ratio of soil microorganism biomass under P input was beneficial for soil C sequestration, which offered a "win-win" relationship for the maximum balance point between C sequestration and P availability for rice production in the face of climate change. PMID

  16. Stability and heavy metal distribution of soil aggregates affected by application of apatite, lime, and charcoal.

    Science.gov (United States)

    Cui, Hongbiao; Ma, Kaiqiang; Fan, Yuchao; Peng, Xinhua; Mao, Jingdong; Zhou, Dongmei; Zhang, Zhongbin; Zhou, Jing

    2016-06-01

    Only a few studies have been reported on the stability and heavy metal distribution of soil aggregates after soil treatments to reduce the availability of heavy metals. In this study, apatite (22.3 t ha(-1)), lime (4.45 t ha(-1)), and charcoal (66.8 t ha(-1)) were applied to a heavy metal-contaminated soil for 4 years. The stability and heavy metal distribution of soil aggregates were investigated by dry and wet sieving. No significant change in the dry mean weight diameter was observed in any treatments. Compared with the control, three-amendment treatments significantly increased the wet mean weight diameter, but only charcoal treatment significantly increased the wet aggregate stability. The soil treatments increased the content of soil organic carbon, and the fraction 0.25-2 mm contained the highest content of soil organic carbon. Amendments' application slightly increased soil total Cu and Cd, but decreased the concentrations of CaCl2 -extractable Cu and Cd except for the fraction 2 and 0.25-2 mm contained the highest concentrations of CaCl2-extractable Cu and Cd, accounted for about 74.5-86.8 % of CaCl2-extractable Cu and Cd in soil. The results indicated that amendments' application increased the wet soil aggregate stability and decreased the available Cu and Cd. The distribution of available heavy metals in wet soil aggregates was not controlled by soil aggregate stability, but possibly by soil organic carbon. PMID:26893180

  17. Climate, soil texture, and soil types affect the contributions of fine-fraction-stabilized carbon to total soil organic carbon in different land uses across China.

    Science.gov (United States)

    Cai, Andong; Feng, Wenting; Zhang, Wenju; Xu, Minggang

    2016-05-01

    Mineral-associated organic carbon (MOC), that is stabilized by fine soil particles (i.e., silt plus clay, clay) in soil, highlighting the importance of soil texture in stabilizing organic carbon across various climate zones. In cropland, different fertilization practices and land uses (e.g., upland, paddy, and upland-paddy rotation) significantly altered MOC/TSOC ratios, but not in cropping systems (e.g., mono- and double-cropping) characterized by climatic differences. This study demonstrates that the MOC/TSOC ratio is mainly driven by soil texture, soil types, and related climate and land uses, and thus the variations in MOC/TSOC ratios should be taken into account when quantitatively estimating soil C sequestration potential of silt plus clay particles on a large scale. PMID:26905446

  18. Ecology and living conditions of groundwater fauna

    Energy Technology Data Exchange (ETDEWEB)

    Thulin, Barbara (Geo Innova AB (Sweden)); Hahn, Hans Juergen (Arbeitsgruppe Grundwasseroekologie, Univ. of Koblenz-Landau (Germany))

    2008-09-15

    This report presents the current state of ecological knowledge and applied research relating to groundwater. A conceptual picture is given of groundwater fauna occurrence in regard to Swedish environmental conditions. Interpretation features for groundwater fauna and applications are outlined. Groundwater is one of the largest and oldest limnic habitats populated by a rich and diverse fauna. Both very old species and species occurring naturally in brackish or salt water can be found in groundwater. Groundwater ecosystems are heterotrophic; the fauna depends on imports from the surface. Most species are meiofauna, 0.3-1 mm. The food chain of groundwater fauna is the same as for relatives in surface water and salt water. Smaller animals graze biofilms and detritus, larger animals act facutatively as predators. A difference is that stygobiotic fauna has become highly adapted to its living space and tolerates very long periods without food. Oxygen is a limiting factor, but groundwater fauna tolerates periods with low oxygen concentrations, even anoxic conditions. For longer periods of time a minimum oxygen requirement of 1 mg/l should be fulfilled. Geographic features such as Quaternary glaciation and very old Pliocene river systems are important for distribution patterns on a large spatial scale, but aquifer characteristics are important on a landscape scale. Area diversity is often comparable to surface water diversity. However, site diversity is low in groundwater. Site specific hydrological exchange on a geological facies level inside the aquifer, e.g. porous, fractured and karstic aquifers as well as the hyporheic zone, controls distribution patterns of groundwater fauna. For a better understanding of controlling factors indicator values are suggested. Different adequate sampling methods are available. They are representative for the aquifer, but a suitable number of monitoring wells is required. The existence of groundwater fauna in Sweden is considered as very

  19. Ecology and living conditions of groundwater fauna

    International Nuclear Information System (INIS)

    This report presents the current state of ecological knowledge and applied research relating to groundwater. A conceptual picture is given of groundwater fauna occurrence in regard to Swedish environmental conditions. Interpretation features for groundwater fauna and applications are outlined. Groundwater is one of the largest and oldest limnic habitats populated by a rich and diverse fauna. Both very old species and species occurring naturally in brackish or salt water can be found in groundwater. Groundwater ecosystems are heterotrophic; the fauna depends on imports from the surface. Most species are meiofauna, 0.3-1 mm. The food chain of groundwater fauna is the same as for relatives in surface water and salt water. Smaller animals graze biofilms and detritus, larger animals act facutatively as predators. A difference is that stygobiotic fauna has become highly adapted to its living space and tolerates very long periods without food. Oxygen is a limiting factor, but groundwater fauna tolerates periods with low oxygen concentrations, even anoxic conditions. For longer periods of time a minimum oxygen requirement of 1 mg/l should be fulfilled. Geographic features such as Quaternary glaciation and very old Pliocene river systems are important for distribution patterns on a large spatial scale, but aquifer characteristics are important on a landscape scale. Area diversity is often comparable to surface water diversity. However, site diversity is low in groundwater. Site specific hydrological exchange on a geological facies level inside the aquifer, e.g. porous, fractured and karstic aquifers as well as the hyporheic zone, controls distribution patterns of groundwater fauna. For a better understanding of controlling factors indicator values are suggested. Different adequate sampling methods are available. They are representative for the aquifer, but a suitable number of monitoring wells is required. The existence of groundwater fauna in Sweden is considered as very

  20. Ordovician Rhynchonelliform Brachiopod Biogeography and Faunas

    DEFF Research Database (Denmark)

    Liljeroth, Maria

    The distribution of the Ordovician (~444–488 Ma) rhynchonelliform brachiopods was investigated for identification of biogeographic provinces and areas constituting focal points for taxon speciation, and to describe the faunas and biodiversity associated with the provinces, palaeoplates, and terra...

  1. Biogeochemical factors affecting mercury methylation rate in two contaminated floodplain soils

    Directory of Open Access Journals (Sweden)

    T. Frohne

    2011-09-01

    Full Text Available An automated biogeochemical microcosm system allowing controlled variation of redox potential (EH in soil suspensions was used to assess the effect of various factors on the mobility of mercury (Hg as well as on the methylation of Hg in two contaminated floodplain soils with different Hg concentrations (approximately 5 mg kg−1 Hg and >30 mg kg−1 Hg. The experiment was conducted under stepwise variation from reducing (approximately −350 mV at pH 5 to oxidizing conditions (approximately 600 mV at pH 5. Results of phospholipid fatty acids (PLFA analysis indicate the occurrence of sulfate reducing bacteria (SRB such as Desulfobacter species (10me16:0, cy17:0, 10me18:0, cy19:0 or Desulfovibrio species (18:2ω6,9, which are considered to promote Hg methylation. The products of the methylation process are lipophilic, highly toxic methyl mercury species such as the monomethyl mercury ion [MeHg+], which is named as MeHg here. The ln(MeHg/Hgt ratio is assumed to reflect the net production of monomethyl mercury normalized to total dissolved Hg (Hgt concentration. This ratio increases with rising dissolved organic carbon (DOC to Hgt ratio (lnDOC/lnHgt ratio (R2 = 0.39, p < 0.0001, n = 63 whereas the relation between ln(MeHg/Hgt ratio and lnDOC is weaker (R2 = 0.09; p < 0.05; n = 63. In conclusion, the DOC/Hgt ratio might be a more important factor for the Hg net methylation than DOC alone in the current study. Redox variations seem to affect the biogeochemical behavior of dissolved inorganic Hg species and MeHg indirectly through related changes in DOC, sulfur cycle, and microbial community structure whereas E,H and pH values, as well as concentration of dissolved Fe,3+/Fe2+ and Cl seem to play subordinate roles in Hg

  2. Iron biofortification of wheat grains through integrated use of organic and chemical fertilizers in pH affected calcareous soil.

    Science.gov (United States)

    Ramzani, Pia Muhammad Adnan; Khalid, Muhammad; Naveed, Muhammad; Ahmad, Rashid; Shahid, Muhammad

    2016-07-01

    Incidence of iron (Fe) deficiency in human populations is an emerging global challenge. This study was conducted to evaluate the potential of iron sulphate combined with biochar and poultry manure for Fe biofortification of wheat grains in pH affected calcareous soil. In first two incubation studies, rates of sulfur (S) and Fe combined with various organic amendments for lowering pH and Fe availability in calcareous soil were optimized. In pot experiment, best rate of Fe along with biochar (BC) and poultry manure (PM) was evaluated for Fe biofortification of wheat in normal and S treated low pH calcareous soil. Fe applied with BC provided fair increase in root-shoot biomass and photosynthesis up to 79, 53 and 67%, respectively in S treated low pH soil than control. Grain Fe and ferritin concentration was increased up to 1.4 and 1.2 fold, respectively while phytate and polyphenol was decreased 35 and 44%, respectively than control in treatment where Fe was applied with BC and S. In conclusion, combined use of Fe and BC could be an effective approach to improve growth and grain Fe biofortification of wheat in pH affected calcareous soil. PMID:27179316

  3. Phytoremediation of salt-affected soils: a review of processes, applicability, and the impact of climate change.

    Science.gov (United States)

    Jesus, João M; Danko, Anthony S; Fiúza, António; Borges, Maria-Teresa

    2015-05-01

    Soil salinization affects 1-10 billion ha worldwide, threatening the agricultural production needed to feed the ever increasing world population. Phytoremediation may be a cost-effective option for the remediation of these soils. This review analyzes the viability of using phytoremediation for salt-affected soils and explores the remedial mechanisms involved. In addition, it specifically addresses the debate over plant indirect (via soil cation exchange enhancement) or direct (via uptake) role in salt remediation. Analysis of experimental data for electrical conductivity (ECe) + sodium adsorption ratio (SAR) reduction and plant salt uptake showed a similar removal efficiency between salt phytoremediation and other treatment options, with the added potential for phytoextraction under non-leaching conditions. A focus is also given on recent studies that indicate potential pathways for increased salt phytoextraction, co-treatment with other contaminants, and phytoremediation applicability for salt flow control. Finally, this work also details the predicted effects of climate change on soil salinization and on treatment options. The synergetic effects of extreme climate events and salinization are a challenging obstacle for future phytoremediation applications, which will require additional and multi-disciplinary research efforts. PMID:25854203

  4. The possibilities of using magnetic susceptibility measurements for evaluating degradation of erosion affected soils

    Czech Academy of Sciences Publication Activity Database

    Jakšík, O.; Kodešová, R.; Kapička, Aleš; Dlouhá, Šárka; Bayarsaikhan, S.; Fér, M.; Klement, A.

    Bratislava: ÚH SAV, 2013 - (Čelková, A.), s. 92-97 ISBN 978-80-89139-30-9. [Stav poznania vo výskume v hydrologických vedách. Smolenice (SK), 23.09.2013-25.09.2013] R&D Projects: GA MZe QJ1230319 Institutional support: RVO:67985530 Keywords : soil erosion * soil degradation * magnetic susceptibility * terrain properties Subject RIV: DF - Soil Science

  5. Carbon stock and humification index of organic matter affected by sugarcane straw and soil management

    Directory of Open Access Journals (Sweden)

    Aline Segnini

    2013-10-01

    Full Text Available The maintenance of sugarcane (Saccharum spp. straw on a soil surface increases the soil carbon (C stocks, but at lower rates than expected. This fact is probably associated with the soil management adopted during sugarcane replanting. This study aimed to assess the impact on soil C stocks and the humification index of soil organic matter (SOM of adopting no-tillage (NT and conventional tillage (CT for sugarcane replanting. A greater C content and stock was observed in the NT area, but only in the 0-5 cm soil layer (p < 0.05. Greater soil C stock (0-60 cm was found in soil under NT, when compared to CT and the baseline. While C stock of 116 Mg ha-1 was found in the baseline area, in areas under CT and NT systems the values ranged from 120 to 127 Mg ha-1. Carbon retention rates of 0.67 and 1.63 Mg C ha-1 year-1 were obtained in areas under CT and NT, respectively. Laser-Induced Fluorescence Spectroscopy showed that CT makes the soil surface (0-20 cm more homogeneous than the NT system due to the effect of soil disturbance, and that the SOM humification index (H LIF is larger in CT compared to NT conditions. In contrast, NT had a gradient of increasing H LIF, showing that the entry of labile organic material such as straw is also responsible for the accumulation of C in this system. The maintenance of straw on the soil surface and the adoption of NT during sugarcane planting are strategies that can increase soil C sequestration in the Brazilian sugarcane sector.

  6. Current Status of Trace Metal Pollution in Soils Affected by Industrial Activities

    OpenAIRE

    Ehsanul Kabir; Sharmila Ray; Ki-Hyun Kim; Hye-On Yoon; Eui-Chan Jeon; Yoon Shin Kim; Yong-Sung Cho; Seong-Taek Yun; Richard J. C. Brown

    2012-01-01

    There is a growing public concern over the potential accumulation of heavy metals in soil, owing to rapid industrial development. In an effort to describe the status of the pollutions of soil by industrial activities, relevant data sets reported by many studies were surveyed and reviewed. The results of our analysis indicate that soils were polluted most significantly by metals such as lead, zinc, copper, and cadmium. If the dominant species are evaluated by the highest mean concentration obs...

  7. DOC-trail: 20 years of organic and conventional farming affect soil microbial properties

    OpenAIRE

    Oberholzer, H.R.; Mäder, Paul; Fliessbach, Andreas

    2000-01-01

    In a long-term field trial (DOC; = bio-Dynamic, bio-Organic, Conventional) at Therwil, Switzerland, agricultural production systems have been compared since 1978. The production systems differ mainly in the amount and form of fertiliser and plant protection strategy. Crop rotation and soil tillage were the same. In the most prominent systems soil microbial properties were investigated for the first time after two crop rotations in 1990. In 1998, after 3 crop rotations, soil microbial properti...

  8. Particulate Organic Matter Affects Soil Nitrogen Mineralization under Two Crop Rotation Systems.

    Directory of Open Access Journals (Sweden)

    Rongyan Bu

    Full Text Available Changes in the quantity and/or quality of soil labile organic matter between and after different types of cultivation system could play a dominant role in soil nitrogen (N mineralization. The quantity and quality of particulate organic matter (POM and potentially mineralizable-N (PMN contents were measured in soils from 16 paired rice-rapeseed (RR/cotton-rapeseed (CR rotations sites in Hubei province, central China. Then four paired soils encompassing low (10th percentile, intermediate (25th and 75th percentiles, and high (90th percentile levels of soil PMN were selected to further study the effects of POM on soil N mineralization by quantifying the net N mineralization in original soils and soils from which POM was removed. Both soil POM carbon (POM-C and N (POM-N contents were 45.8% and 55.8% higher under the RR rotation compared to the CR rotation, respectively. The PMN contents were highly correlated with the POM contents. The PMN and microbial biomass N (MBN contents concurrently and significantly decreased when POM was removed. The reduction rate of PMN was positively correlated with changes in MBN after the removal of POM. The reduction rates of PMN and MBN after POM removal are lower under RR rotations (38.0% and 16.3%, respectively than CR rotations (45.6% and 19.5%, respectively. Furthermore, infrared spectroscopy indicated that compounds with low-bioavailability accumulated (e.g., aromatic recalcitrant materials in the soil POM fraction under the RR rotation but not under the CR rotation. The results of the present study demonstrated that POM plays a vital role in soil N mineralization under different rotation systems. The discrepancy between POM content and composition resulting from different crop rotation systems caused differences in N mineralization in soils.

  9. Brassica spp cover crop affects soil microbial activity, carbon and nitrogen nutrient dynamics

    OpenAIRE

    Marinari, S.; Papp, R.; Marabottini, R.; Moscatelli, M. C.

    2015-01-01

    A general positive effect of Brassica on soil microbial biomass and its activity was observed at all European sites in no tilled soil at both sampling date. Conversely, Brassica under tillage may produce a negative effect on biochemical properties after CC suppression. The effect of Brassica on C and N dynamics differed among the european sites when soil was tilled. These preliminary results establish the bases for the evaluation of the interaction between the pedoclimatic conditions and Bras...

  10. Different Degrees of Plant Invasion Significantly Affect the Richness of the Soil Fungal Community

    OpenAIRE

    Si, Chuncan; Liu, Xueyan; Wang, Congyan; Wang, Lei; Dai, Zhicong; Qi, Shanshan; Du, Daolin

    2013-01-01

    Several studies have shown that soil microorganisms play a key role in the success of plant invasion. Thus, ecologists have become increasingly interested in understanding the ecological effects of biological invasion on soil microbial communities given continuing increase in the effects of invasive plants on native ecosystems. This paper aims to provide a relatively complete depiction of the characteristics of soil microbial communities under different degrees of plant invasion. Rhizospheric...

  11. Urban cultivation in allotments maintains soil qualities adversely affected by conventional agriculture

    OpenAIRE

    Edmondson, Jill L.; Davies, Zoe G.; Gaston, Kevin J.; Leake, Jonathan R.

    2014-01-01

    1. Modern agriculture, in seeking to maximize yields to meet growing global food demand, has caused loss of soil organic carbon (SOC) and compaction, impairing critical regulating and supporting ecosystem services upon which humans also depend. Own-growing makes an important contribution to food security in urban areas globally, but its effects on soil qualities that underpin ecosystem service provision are currently unknown. 2. We compared the main indicators of soil quality; SOC storage...

  12. The ash in forest fire affected soils control the soil losses. Part 2. Current and future research challenges

    Science.gov (United States)

    Pereira, Paulo; Cerdà, Artemi

    2013-04-01

    Ash distribution on soil surface and impacts on soil properties received a great attention in recently (Pereira et al., 2010; Pereira et al., 2013). Ash it is a highly mobile material that can be easily transported wind, especially in severe wildland fires, where organic matter is reduced to dust, due the high temperatures of combustion. In the immediate period after the fire, ash cover rules soil erosion as previous researchers observed (Cerdà, 1998a; 1998b) and have strong influence on soil hydrological properties, such as water retention (Stoof et al. 2011 ) and wettability (Bodi et al., 2011). Ash it is also a valuable source of nutrients important for plant recuperation (Pereira et al., 2011; Pereira et al., 2012), but can act also as a source contamination, since are also rich in heavy metals (Pereira and Ubeda, 2010). Ash has different physical and chemical properties according the temperature of combustion, burned specie and time of exposition (Pereira et al., 2010). Thus this different properties will have different implications on soil properties including erosion that can increase due soil sealing (Onda et al. 2008) or decrease as consequence of raindrop impact reduction (Cerdà and Doerr, 2008). The current knowledge shows that ash has different impacts on soil properties and this depends not only from the type of ash produced, but of the soil properties (Woods and Balfour, 2010). After fire wind and water strong redistribute ash on soil surface, increasing the vulnerability of soil erosion in some areas, and reducing in others. Understand this mobility is fundamental have a better comprehension about the spatial and temporal effects of ash in soil erosion. Have a better knowledge about this mobility is a priority to future research. Other important aspects to have to be assessed in the future are how ash particulates percolate on soil and how ash chemical composition is important to induce soil aggregation and dispersion. How soil micro topography

  13. Soil NH+4 Fixation and Fertilizer N Recovery as Affected by Soil Moisture and Fertilizer Application Methods

    Institute of Scientific and Technical Information of China (English)

    TONG Yah-An; O.EMTERYD; H.GRIP; LU Dian-Qing

    2004-01-01

    Ammonium fixation and the effects of soil moisture and application methods on fertilizer N recovery were investigated in two soils of Shaanxi Province,China,a Luvisol and an Entisol,through two experiments performed in the laboratory and in a glass shelter,respectively,by using ammonium bicarbonate (NH4HCO3). The laboratory closed incubation box experiment was conducted using the Luvisol to study NH4+ fixation rate at soil moisture levels of 10.1%,22.7% and 35.3% water filled pore space (WFPS). The fixed NH4+-N increased dramatically to 51% and 66%,67% and 74%,and 82% and 85% 1,2 and 36 h after fertilizer incorporation at moisture levels of 10.1% and 22.7% WFPS and 35.3%WFPS,respectively. The rapid NH4+ fixation rates at all moisture levels could help prevent NH4+ losses from ammonia volatilization. In the glass shelter pot experiment,N fertilizer was applied by either banding (in a concentrated strip)or incorporating (thoroughly mixing) with the Entisol and the Luvisol. An average of 74.2% of the added N fertilizer was recovered 26 days after application to the Luvisol,while only 61.4% could be recovered from the Entisol,due to higher NH4+ fixation capacity of the Luvisol. The amount of fixed NH4+ decreased with increasing WFPS. The amount of fixed NH4+ in the incorporated fertilizer treatment was,on average,10% higher than that in the banded treatment.Higher NH4+ fixation rates could prevent N loss and thus increase N recovery. The results from the Luvisol showed lower nitrogen recovery as soil moisture level increased,which could be explained by the fact that most of the fixed NH4+ was still not released when the soil moisture level was low. When the fertilizer was incorporated into the soil,the recovery of N increased,compared with the banded treatment,by an average of 26.2% in the Luvisol and 11.2% in the Entisol,which implied that when farmers applied fertilizer,it would be best to mix it well with the soil.

  14. Responses of the soil decomposer community to the radioactive contamination

    International Nuclear Information System (INIS)

    The knowledge about biodiversity and about reasons and laws of dynamics of decomposer invertebrates has exclusively important (rather applied, or theoretical) significance for soil science. Earthworms and millipedes are probably the most important members of the soil biota and major contributors to total zoo-mass. Their activities are such that they are extremely important in maintaining soil fertility in a variety of ways. They play an important part in the redistribution of radionuclides accumulated in the natural biogeocenoses and accumulation of radionuclides in their bodies depends on their concentration in the habitat. Since radionuclides can limit biological activity, studies to estimate the tolerance of decomposer community to potentially toxic radiators are needed. The effect of radioactive contamination on the soil invertebrates and decomposition processes in the different biogeocenoses we intensively studied during 17 years after Chernobyl accident. The soil invertebrates were collected according to generally accepted method by M. Ghilyarov. Soil samples were 0,25 m2 and animals were extracted from samples by hand sorting. Usually decomposition was affected by the presence of decomposer fauna. Considerable differences were found in the species number. The species composition of sites differed clearly. The study showed that the fauna was poorer under increasing levels of radioactive contamination. The higher radionuclide content was found to result in suppression of decomposer community. The results showed a vertical migration of earthworms to deeper soil layers with increasing of radioactive contamination. With the absence of decomposer fauna due to migration to the deeper layer and mortality, the layer of litter increased. The results show that the earthworms were of small size. Cocoon production decreased. Radioactive contamination altered the process of reproduction and age structure of decomposer fauna. The invertebrates collected from the

  15. Mercury and other trace elements in soils affected by the mine tailing spill in Aznalcóllar (SW Spain).

    Science.gov (United States)

    Cabrera, F; Ariza, J; Madejón, P; Madejón, E; Murillo, J M

    2008-02-15

    The Aznalcóllar accident (28th April 1998) occurred because the collapse of the tailing-dam dike of the Aznalcóllar-Los Frailes mines. Soils were affected by a slurry of acidic water loaded with trace elements, finely divided metal sulphides, and materials used in the refining /floating process. Studies carried out before and after the soil restoration activities (sludge removal, amending, tilling, and afforestation) showed severe trace-element contamination (mainly As, Cd, Cu, Pb, Tl and Zn) in the superficial layer of the sludge-affected soils. Despite Hg being an important component of the Los Frailes ore and therefore of the contaminant sludge, data on Hg content of sludge-affected soils are scarce and sometimes controversial. The aim of this study was to determine the effect of the spill and of restoration measures on the Hg content of soils and how this related to other elements. Concentration of Hg immediately after the spill was 8-fold above background (0.061+/-0.012 mg kg(-1); mean+/-SD) at the surface (0-5 cm) and 3-4-fold greater in deeper layers (0-20; 0-50 cm). After the remediation measures, mean values of Hg and other elements (As, Cd, Cu, Pb and Zn) were very variable and remained above background values. These anomalies are due to the sludge left on the soil surface or buried during restoration operations, resulting in an irregular distribution of trace elements. The highest values for the less mobile elements (up to 176 mg kg(-1) As, 2.36 mg kg(-1) Hg and 1556 mg kg(-1) Pb) were observed in the area 1 km downstream of the tailings dam. PMID:18029288

  16. Congo grass grown in rotation with soybean affects phosphorus bound to soil carbon

    Directory of Open Access Journals (Sweden)

    Alexandre Merlin

    2014-06-01

    Full Text Available The phosphorus supply to crops in tropical soils is deficient due to its somewhat insoluble nature in soil, and addition of P fertilizers has been necessary to achieve high yields. The objective of this study was to examine the mechanisms through which a cover crop (Congo grass - Brachiaria ruziziensis in rotation with soybean can enhance soil and fertilizer P availability using long-term field trials and laboratory chemical fractionation approaches. The experimental field had been cropped to soybean in rotation with several species under no-till for six years. An application rate of no P or 240 kg ha-1 of P2O5 had been applied as triple superphosphate or as Arad rock phosphate. In April 2009, once more 0.0 or 80.0 kg ha-1 of P2O5 was applied to the same plots when Congo grass was planted. In November 2009, after Congo grass desiccation, soil samples were taken from the 0-5 and 5-10 cm depth layer and soil P was fractionated. Soil-available P increased to the depth of 10 cm through growing Congo grass when P fertilizers were applied. The C:P ratio was also increased by the cover crop. Congo grass cultivation increased P content in the soil humic fraction to the depth of 10 cm. Congo grass increases soil P availability by preventing fertilizer from being adsorbed and by increasing soil organic P.

  17. Bioavailability of zinc and phosphorus in calcareous soils as affected by citrate exudation

    OpenAIRE

    Duffner, A.; Hoffland, E.; Temminghoff, E.J.M.

    2012-01-01

    Aims Zinc (Zn) and phosphorus (P) deficiency often occurs at the same time and limits crop production in many soils. It has been suggested that citrate root exudation is a response of plants to both deficiencies. We used white lupin (Lupinus albus L.) as a model plant to clarify if citrate exuded by roots could increase the bioavailability of Zn and P in calcareous soils. Methods White lupin was grown in nutrient solution and in two calcareous soils in a rhizobox. Rhizosphere soil solution wa...

  18. Amending greenroof soil with biochar to affect runoff water quantity and quality

    International Nuclear Information System (INIS)

    Numbers of greenroofs in urban areas continue to grow internationally; so designing greenroof soil to reduce the amount of nutrients in the stormwater runoff from these roofs is becoming essential. This study evaluated changes in extensive greenroof water discharge quality and quantity after adding biochar, a soil amendment promoted for its ability to retain nutrients in soils and increase soil fertility. Prototype greenroof trays with and without biochar were planted with sedum or ryegrass, with barren soil trays used as controls. The greenroof trays were subjected to two sequential 7.4 cm/h rainfall events using a rain simulator. Runoff from the rain events was collected and evaluated. Trays containing 7% biochar showed increased water retention and significant decreases in discharge of total nitrogen, total phosphorus, nitrate, phosphate, and organic carbon. The addition of biochar to greenroof soil improves both runoff water quality and retention. - Highlights: → Biochar in green roof soil reduces nitrogen and phosphorus in the runoff. → Addition of biochar reduces turbidity of runoff. → Addition of biochar reduces total organic carbon content in runoff by 67-72%. → Biochar improves water retention of saturated soil. - In this controlled laboratory experiment, greenroof soil was amended by the addition of biochar, which reduced the water runoff concentration of nitrogen, phosphorus, and organic carbon.

  19. Microbial Biomass Carbon and Total Organic Carbon of Soils as Affected by Rubber Cultivation

    Institute of Scientific and Technical Information of China (English)

    ZHANG Hua; ZHANG Gan-Lin

    2003-01-01

    Soil samples were collected from different rubber fields in twenty-five plots selected randomly in the Experimental Farm of the Chinese Academy of Tropical Agriculture Sciences located in Hainan, China, to analyse the ecological effect of rubber cultivation. The results showed that in the tropical rubber farm,soil microbial biomass C (MBC) and total organic C (TOC) were relatively low in the content but highly correlated with each other. After rubber tapping, soil MBC of mature rubber fields decreased significantly,by 55.5%, compared with immature rubber fields. Soil TOC also decreased but the difference was not significant. Ratios of MBC to TOC decreased significantly. The decreasing trend of MBC stopped at about ten years of rubber cultivation. After this period, soil MBC increased relatively while soil TOC still kept in decreasing. Soil MBC changes could be measured to predict the tendency of soil organic matter changes due to management practices in a tropical rubber farm several years before the changes in soil TOC become detectable.

  20. Production of biochar out of organic urban waste to amend salt affected soils in the basin of Mexico

    Science.gov (United States)

    Chavez Garcia, Elizabeth; Siebe, Christina

    2016-04-01

    Biochar is widely recognized as an efficient tool for carbon sequestration and soil fertility. The understanding of its chemical and physical properties, strongly related to the biomass and production conditions, is central to identify the most suitable application of biochar. On the other hand, salt affected soils reduce the value and productivity of extensive areas worldwide. One feasible option to recover them is to add organic amendments, which improve water holding capacity and increase sorption sites for cations as sodium. The former lake Texcoco in the basin of Mexico has been a key area for the control of surface run-off and air quality of Mexico City. However, the high concentrations of soluble salts in their soils do not allow the development of a vegetation cover that protects the soil from wind erosion, being the latter the main cause of poor air quality in the metropolitan area during the dry season. On the other hand, the population of the city produces daily 2000 t of organic urban wastes, which are currently composted. Thus, we tested if either compost or biochar made out of urban organic waste can improve the salt affected soils of former lake Texcoco to grow grass and avoid wind erosion. We examined the physico-chemical properties of biochar produced from urban organic waste under pyrolysis conditions. We also set up a field experiment to evaluate the addition of these amendments into the saline soils of Texcoco. Our preliminary analyses show biochar yield was ca. 40%, it was mainly alkaline (pH: 8-10), with a moderate salt content (electrical conductivity: 0.5-3 mS/cm). We show also results of the initial phase of the field experiment in which we monitor the electrical conductivity, pH, water content, water tension and soil GHG fluxes on small plots amended with either biochar or compost in three different doses.

  1. [Carbon source metabolic diversity of soil microbial community under different climate types in the area affected by Wenchuan earthquake].

    Science.gov (United States)

    Zhang, Guang-Shuai; Lin, Yong-Ming; Ma, Rui-Feng; Deng, Hao-Jun; Du, Kun; Wu, Cheng-Zhen; Hong, Wei

    2015-02-01

    The MS8.0 Wenchuan earthquake in 2008 led to huge damage to land covers in northwest Sichuan, one of the critical fragile eco-regions in China which can be divided into Semi-arid dry hot climate zone (SDHC) and Subtropical humid monsoon climate zone (SHMC). Using the method of Bilog-ECO-microplate technique, this paper aimed to determine the functional diversity of soil microbial community in the earthquake-affected areas which can be divided into undamaged area (U), recover area (R) and damaged area without recovery (D) under different climate types, in order to provide scientific basis for ecological recovery. The results indicated that the average-well-color-development (AWCD) in undamaged area and recovery area showed SDHC > SHMC, which was contrary to the AWCD in the damaged area without recovery. The AWCD of damaged area without recovery was the lowest in both climate zones. The number of carbon source utilization types of soil microbial in SHMC zone was significantly higher than that in SDHC zone. The carbon source utilization types in both climate zones presented a trend of recover area > undamaged area > damaged area without recovery. The carbon source metabolic diversity characteristic of soil microbial community was significantly different in different climate zones. The diversity index and evenness index both showed a ranking of undamaged area > recover area > damaged area without recovery. In addition, the recovery area had the highest richness index. The soil microbial carbon sources metabolism characteristic was affected by soil nutrient, aboveground vegetation biomass and vegetation coverage to some extent. In conclusion, earthquake and its secondary disasters influenced the carbon source metabolic diversity characteristic of soil microbial community mainly through the change of aboveground vegetation and soil environmental factors. PMID:26031097

  2. 137Cs and 90Sr mobility in soils and transfer in soil-plant systems in the Novozybkov district affected by the Chernobyl accident

    International Nuclear Information System (INIS)

    The Chernobyl radionuclides distribution and mobility in soils and uptake by plants have been studied in seminatural and agricultural moraine and in fluvioglacial landscapes typical for the areas of the Bryansk region affected by the accident.The major part of the Chernobyl 137Cs accumulated in the topsoil is insoluble in water, 40 to 93% of this radionuclide is strongly fixed by soil, while 70 to 90% of the 90Sr is present in water soluble, exchangeable and weak-acid soluble forms. Radionuclide vertical migration is most pronounced in local depressions with organic and gley soils in which both radionuclides are detected to the depth of 30-40 cm.In woodlands, most of the 137grasses. Transfer to grasses in local depressions is usually higher compared with the dry levees. Observed exclusions are assumed to be due to comparatively low mobility of 137Cs and relatively high K content in soil. 137Cs accumulation in potato tubers grown on sandy soddy podzolic watershed soils mainly corresponds to its total amount in soils; uptake of 90Sr depends upon the percentage of its most mobile fraction.Pronounced relief is proved to cause different patterns in distribution and migration of radionuclides in soils and local food chains. The study showed it to be true for private farms situated in different landscape positions within the same settlement.The forest litter, topsoil and products, and flood plain pastures, especially localities in depressions are critical materials for the long-term radioecological monitoring of the contaminated landscapes of the study area and those of similar conditions. Population of the areas within the zone of contamination exceeding 15Ci/km2 (555kBq/m2) should be recommended to exclude local forest products from their diets and to avoid cattle grazing on wet flood plain meadows without remediation. (Copyright (c) 1998 Elsevier Science B.V., Amsterdam. All rights reserved.)

  3. Quality of fresh organic matter affects priming of soil organic matter and substrate utilization patterns of microbes.

    Science.gov (United States)

    Wang, Hui; Boutton, Thomas W; Xu, Wenhua; Hu, Guoqing; Jiang, Ping; Bai, Edith

    2015-01-01

    Changes in biogeochemical cycles and the climate system due to human activities are expected to change the quantity and quality of plant litter inputs to soils. How changing quality of fresh organic matter (FOM) might influence the priming effect (PE) on soil organic matter (SOM) mineralization is still under debate. Here we determined the PE induced by two (13)C-labeled FOMs with contrasting nutritional quality (leaf vs. stalk of Zea mays L.). Soils from two different forest types yielded consistent results: soils amended with leaf tissue switched faster from negative PE to positive PE due to greater microbial growth compared to soils amended with stalks. However, after 16 d of incubation, soils amended with stalks had a higher PE than those amended with leaf. Phospholipid fatty acid (PLFA) results suggested that microbial demand for carbon and other nutrients was one of the major determinants of the PE observed. Therefore, consideration of both microbial demands for nutrients and FOM supply simultaneously is essential to understand the underlying mechanisms of PE. Our study provided evidence that changes in FOM quality could affect microbial utilization of substrate and PE on SOM mineralization, which may exacerbate global warming problems under future climate change. PMID:25960162

  4. Ammonium and nitrate in soil and upland rice yield as affected by cover crops and their desiccation time

    Directory of Open Access Journals (Sweden)

    Adriano Stephan Nascente

    2012-12-01

    Full Text Available The objective of this work was to evaluate the effect of cover crops and their desiccation times on upland rice yield and on the levels of nitrate and ammonium in a no-tillage soil. The experiment was carried out in a randomized blocks, with split plots and three replicates. Cover crops (plots were sowed in the off-season (March 2009. In November 2009, at 30, 20, 10 and 0 days before rice sowing (split plots, herbicide was applied on the cover crops (fallow, Panicum maximum, Urochloa ruziziensis, U. brizantha and millet. Straw and soil were sampled (0 - 10 cm at the sowing day, and after 7, 14, 21, 28 and 35 days. Straws from millet and fallow were degraded more rapidly and provided the lowest level of nitrate in the soil. Urochloa ruziziensis, U. brizantha and P. maximum produced higher amounts of dry matter, and provided the highest levels of nitrate in the soil. Millet provides the lowest nitrate/ammonium ratio and the highest upland rice yield. Desiccations carried out at 30 and 20 days before sowing had the largest levels of nitrate in the soil at the sowing date. Nitrogen content and forms in the soil are affected by cover crops and their desiccation times.

  5. Endoparasite control strategies: implications for biodiversity of native fauna.

    Science.gov (United States)

    Spratt, D M

    1997-02-01

    Efforts to control the spectrum of diseases that affect humans, our crops and our animals pose problems which need to be debated openly. Widespread use of chemicals in such a broad sphere raises important concerns not only about safety for the users, consumers and target species, but especially about the not so obvious effects upon the ecosystems in which they are used. Some undetermined level of biological diversity is necessary to maintain ecological function and resilience. These, in turn, are necessary for generating the biological resources (trees, fish, wildlife, crops) and ecological services (watershed protection, air cleansing, climate stabilisation, erosion control) on which economic activity and human welfare depend. The driving forces behind decline of biodiversity stem entirely from human activities. Underlying causes are those resulting from the cultural and social factors associated with economic activities and lead to direct depletion of species, and degradation or destruction of habitats. The broad spectrum and high efficacy of the macrocyclic lactones against nematode and arthropod parasites of livestock and companion animals are unprecedented. Cattle, horses, sheep, swine, dogs--to varying degrees all are utilised by humans for economic gain. Detrimental impact upon non-target animals is considered acceptable in eradicating parasites because of their economic importance to commercial livestock production. Production will increase when these parasites are eliminated, but we remain oblivious to the long-term consequences of our actions. What are the ecological limits to rural economic activities? Decomposing animal faeces help to maintain our ecosystem by returning valuable nutrients to the soil. Dung fauna-fungi, yeast, bacteria, nematodes, insects and earthworms--play a non-conspicuous but important and varied role in this decomposition process, a role dependent upon many factors, especially environmental ones. Anthelmintics and pesticides are of

  6. Fauna in nuclear power plant localities on Czechoslovak territory. I

    International Nuclear Information System (INIS)

    The territory of the CSSR comprises seven types of fauna: 1. arboreal, 2. steppe-eremial, 3. oreo-tundral, 3. fauna spread over large areas, 5. special fauna of the limnic biocycle, 6. epiareal elements of terrestrial fauna and 7. anthropogenically conditioned fauna. Each group has its characteristics and examples are given of animals belonging to the said groups. On the basis of a survey of local fauna and data on a nuclear power plant sited in the respective locality measures may be taken to protect local fauna and to predict its further development. (E.S.). 8 refs

  7. Macrobenthic fauna community in the Middle Songkhla Lake, Southern Thailand

    Directory of Open Access Journals (Sweden)

    Angsupanich, S.

    2005-02-01

    richness was in the SW monsoon season (light rain, June-August. Polychaetes and molluscs tended to decrease in the NE monsoon season with heavy rain from December-February, while crustaceans increased during this time. The best fitting of the environmental variables to explain the macrobenthic fauna community pattern of the Inner Songkhla Lake was an 8-variable combination of %clay, %silt, %organic carbon, soil pH, depth, dissolved oxygen, total suspended solid and temperature (harmonic rank correlation coefficient, ρw = 0.84.

  8. Transport of manure-borne testosterone in soils affected by artificial rainfall events.

    Science.gov (United States)

    Qi, Yong; Zhang, Tian C

    2016-04-15

    Information is very limited on fate and transport of steroidal hormones in soils. In this study, the rainfall simulation tests were conducted with a soil slab reactor to investigate the transport of manure-borne testosterone in a silty-clay loam soil under six controllable operation conditions (i.e., three rainfall intensities and two tillage practices). The properties [e.g., rainwater volume, particle size distribution (PSD)] of the slurry samples collected in runoff and leachate at different time intervals were measured; their correlation with the distribution of testosterone among runoff, leachate and soil matrix was analyzed. The results indicated that more than 88% of the testosterone was held by the applied manure and/or soil matrix even under the rainfall intensity of 100-year return frequency. The runoff facilitated testosterone transport through both dissolved and particle-associated phases, with the corresponding mass ratio being ∼7 to 3. Soil particles collected through runoff were mainly silt-sized aggregates (STA) and clays, indicating the necessity of using partially-dispersed soil particles as testing materials to conduct batch tests (e.g., sorption/desorption). No testosterone was detected at the soil depth >20 cm or in the leachate samples, indicating that transport of testosterone through the soil is very slow when there is no preferential flow. Tillage practice could impede the transport of testosterone in runoff. For the first time, results and the methodologies of this study allow one to quantify the hormone distribution among runoff, leachate and soil matrix at the same time and to obtain a comprehensive picture of the F/T of manure-borne testosterone in soil-water environments. PMID:26922564

  9. Soil water content and yield variability in vineyards of Mediterranean northeastern Spain affected by mechanization and climate variability

    Science.gov (United States)

    Ramos, M. C.

    2006-07-01

    The objective of this paper was to analyse the combined influence of the Mediterranean climate variability (particularly the irregular rainfall distribution throughout the year) and the land transformations carried out in vineyards of northeastern Spain on soil water content evolution and its influence on grape production. The study was carried out in a commercial vineyard located in the Anoia-Alt Penedès region (Barcelona province, northeastern Spain), which was prepared for mechanization with important land transformations. Two plots were selected for the study: one with low degree of transformation of the soil profile, representing a non-disturbed situation, and the second one in which more than 3 m were cut in the upper part of the plot and filled in the lower part, representing the disturbed situation. Soil water content was evaluated at three positions along the slope in each plot and at three depths (0-20, 20-40, 40-60 cm) during the period 1999-2001, years with different rainfall characteristics, including extreme events and long dry periods. Rainfall was recorded in the experimental field using a pluviometer linked to a data-logger. Runoff rates and yield were evaluated at the same positions. For the same annual rainfall, the season of the year in which rainfall is recorded and its intensity are critical for water availability for crops. Soil water content varies within the plot and is related to the soil characteristics existing at the different positions of the landscape. The differences in soil depth created by soil movements in the field mechanization give rise to significant yield reductions (up to 50%) between deeper and shallow areas. In addition, for the same annual rainfall, water availability for crops depends on its distribution over the year, particularly in soils with low water-storage capacity. The yield was strongly affected in years with dry or very dry winters.

  10. Aggregate stability as affected by polyacrylamide molecular weight, soil texture and water quality

    Science.gov (United States)

    The favorable effects of the environmentally friendly, non toxic, anionic polyacrylamide (PAM) as a soil conditioner have long been established. However, some uncertainties exist regarding the effects of PAM molecular weight (MW) on its performance as a soil amendment and the ability of PAM to penet...

  11. Biochar affects carbon composition and stability in soil: a combined spectroscopy-microscopy study

    Science.gov (United States)

    Hernandez-Soriano, Maria C.; Kerré, Bart; Kopittke, Peter M.; Horemans, Benjamin; Smolders, Erik

    2016-01-01

    The use of biochar can contribute to carbon (C) storage in soil. Upon addition of biochar, there is a spatial reorganization of C within soil particles, but the mechanisms remain unclear. Here, we used Fourier transformed infrared-microscopy and confocal laser scanning microscopy to examine this reorganization. A silty-loam soil was amended with three different organic residues and with the biochar produced from these residues and incubated for 237 d. Soil respiration was lower in biochar-amended soils than in residue-amended soils. Fluorescence analysis of the dissolved organic matter revealed that biochar application increased a humic-like fluorescent component, likely associated with biochar-C in solution. The combined spectroscopy-microscopy approach revealed the accumulation of aromatic-C in discrete spots in the solid-phase of microaggregates and its co-localization with clay minerals for soil amended with raw residue or biochar.The co-localization of aromatic-C:polysaccharides-C was consistently reduced upon biochar application. We conclude that reduced C metabolism is an important mechanism for C stabilization in biochar-amended soils. PMID:27113269

  12. The affect of industrial activities on zinc in alluvial Egyptian soil determined using neutron activation analysis

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Thirty-two surface (0-20 cm) soil samples were collected from different locations in Egypt representing non-polluted,moderately and highly polluted soils.The aim of this study was to evaluate total Zn content in alluvial soils of Nile Delta in Egypt by using the delayed neutron activation analysis technique (DNAA),in the irradiation facilities of the first Egyptian research reactor (ET-RR-1).The gamma-ray spectra were recorded with a hyper pure germanium detection system.The well resolved gamma-ray peak at 1116.0 kev was efficiently used for 65Zn content determination.Zn content in non-polluted soil samples ranged between 74.1 and 103.8 ppm with an average of 98.5 + 5.1 ppm.Zn content in moderately polluted soils ranged between 136.0 and 232.5 ppm with an average of 180.1 + 32.6 ppm.The highest Zn levels ranging from 240.0 and 733.0 ppm with an average of 410.3 + 54.4 ppm,were observed in soil samples collected from,either highly polluted agricultural soils exposed to prolonged irrigation with industrial wastewater or surface soil samples from industrial sites.

  13. Post-cold-storage conditioning time affects soil denitrifying enzyme activity

    DEFF Research Database (Denmark)

    Chirinda, Ngonidzashe; Olesen, Jørgen Eivind; Porter, John Roy

    2011-01-01

    Soil denitrifying enzyme activity (DEA) is often assessed after cold storage. Previous studies using the short-term acetylene inhibition method have not considered conditioning time (post-cold-storage warm-up time prior to soil analysis) as a factor influencing results. We observed fluctuations in...

  14. Post cold-storage conditioning time affects soil denitrifying enzyme activity

    OpenAIRE

    Chirinda, Ngonidzashe; J. E. Olesen; Porter, J R

    2011-01-01

    Soil denitrifying enzyme activity (DEA) is often assessed after cold storage.Previous studies using the short-term acetylene inhibition method have not considered conditioning time (post-cold storage warming-up time prior to soil analysis) as a factor influencing results. We observed fluctuations in DEA following cold storage, suggesting a need to consider conditioning time when planning and interpreting results.

  15. Mechanisms that promote bacterial fitness in fungal-affected soil microhabitats

    NARCIS (Netherlands)

    Nazir, Rashid; Warmink, J.A.; Boersma, F.G.H.; van Elsas, J.D.

    2010-01-01

    Soil represents a very heterogeneous environment for its microbiota. Among the soil inhabitants, bacteria and fungi are important organisms as they are involved in key biogeochemical cycling processes. A main energy source driving the system is formed by plants through the provision of plant-fixed (

  16. Zeolite Soil Application Method Affects Inorganic Nitrogen, Moisture, and Corn Growth

    Science.gov (United States)

    Adoption of new management techniques which improve soil water storage and soil nitrogen plant availability yet limit nitrogen leaching may help improve environmental quality. A benchtop study was conducted to determine the influence of a single urea fertilizer rate (224 kilograms of Nitrogen per ...

  17. Assessing dominant factors affecting soil erosion using a portable rainfall simulator

    Institute of Scientific and Technical Information of China (English)

    J.VAHABI; D.NIKKAMI

    2008-01-01

    Investigating the causes of soil erosion is difficult in natural conditions owing to the presence of other factors.Without simplifying the experimental conditions,studying soil behavior with its numerous parameters while considering factors such as vegetation cover,topography,and rainfall is difficult and in most conditions impossible.The application of simulation approaches is therefore necessary to simplify the prototype.In this research,the effects of physical soil factors such as texture and antecedent soil moisture,along with land slope and vegetation cover were evaluated in the Taleghan watershed,lran,using a rainfall simulator and soil erosion plots.For this purpose,a 89 × 120 cm rainfall simulator producing 24.5 and 32 mm/h rainfall intensities of 30 rain duration,as a common condition of the study area,was used at 144 locations over soil erosion plots with dimensions of 95 × 125 cm.Plots had slope classes of 12-20 and 20-30 %,different soil textures,different antecedent soil moistures,and medium to poor vegetation cover conditions.It was found that for 24.5 and 32 mm/h rainfall intensities,the sediment yield had high correlations of-0.771 and -0.796 with vegetation cover and slight correlations of 0.045 and 0.029 with land slope respectively.Regression equations for predicting the sediment yield were also developed for different conditions.

  18. Chemical and biological attributes of a lowland soil affected by land leveling

    Directory of Open Access Journals (Sweden)

    José Maria Barbat Parfitt

    2013-11-01

    Full Text Available The objective of this work was to evaluate the relationship between soil chemical and biological attributes and the magnitude of cuts and fills after the land leveling process of a lowland soil. Soil samples were collected from the 0 - 0.20 m layer, before and after leveling, on a 100 point grid established in the experimental area, to evaluate chemical attributes and soil microbial biomass carbon (MBC. Leveling operations altered the magnitude of soil chemical and biological attributes. Values of Ca, Mg, S, cation exchange capacity, Mn, P, Zn, and soil organic matter (SOM decreased in the soil profile, whereas Al, K, and MBC increased after leveling. Land leveling decreased in 20% SOM average content in the 0 - 0.20 m layer. The great majority of the chemical attributes did not show relations between their values and the magnitude of cuts and fills. The relation was quadratic for SOM, P, and total N, and was linear for K, showing a positive slope and indicating increase in the magnitude of these attributes in cut areas and stability in fill areas. The relationships between these chemical attributes and the magnitude of cuts and fills indicate that the land leveling map may be a useful tool for degraded soil recuperation through amendments and organic fertilizers.

  19. Landscape position moderates how ant nests affect hydrology and soil chemistry across a Chihuahuan Desert watershed

    Science.gov (United States)

    Ants moderate the supply of critical resources such as water and nutrients in desert environments by changing the physical arrangement of soils during nest construction. We measured water infiltration and soil physical and chemical properties on and off the nests of two ant species (Pogonomyrmex rug...

  20. Factors affecting transport of bacteria and microspheres through biochar-amended soils

    Science.gov (United States)

    We have investigated the role of biochar feedstock type (poultry litter extract and pine chips), biochar pyrolysis temperature (350 and 700 oC), biochar application rate (1, 2, and 10%), soil moisture content (saturated and 50% saturation), soil texture (1 and 12 % clay content), and surface propert...

  1. Factors affecting N immobilisation/mineralisation kinetics for cellulose-, glucose- and straw-amended sandy soils

    NARCIS (Netherlands)

    Vinten, A.J.A.; Whitmore, A.P.; Bloem, J.; Howard, R.; Wright, F.

    2002-01-01

    The kinetics of nitrogen immobilization/mineralization for cellulose-, glucose- and straw-amended sandy soils were investigated in a series of laboratory incubations. Three Scottish soils expected to exhibit a range of biological activity were used: aloamy sand, intensively cropped horticultural soi

  2. COSMOS soil water sensing affected by crop biomass and water status

    Science.gov (United States)

    Soil water sensing methods are widely used to characterize water content in the root zone and below, but only a few are capable of sensing soil volumes larger than a few hundred liters. Scientists with the USDA-ARS Conservation & Production Research Laboratory, Bushland, Texas, evaluated: a) the Cos...

  3. 'Fingerprints' of four crop models as affected by soil input data aggregation

    DEFF Research Database (Denmark)

    Angulo, Carlos; Gaiser, Thomas; Rötter, Reimund P;

    2014-01-01

    this study we used four crop models (SIMPLACE, DSSAT-CSM, EPIC and DAISY) differing in the detail of modeling above-ground biomass and yield as well as of modeling soil water dynamics, water uptake and drought effects on plants to simulate winter wheat in two (agro-climatologically and geo......-morphologically) contrasting regions of the federal state of North-Rhine-Westphalia (Germany) for the period from 1995 to 2008. Three spatial resolutions of soil input data were taken into consideration, corresponding to the following map scales: 1:50 000, 1:300 000 and 1:1 000 000. The four crop models were run for water...... all models. Further analysis revealed that the small influence of spatial resolution of soil input data might be related to: (a) the high precipitation amount in the region which partly masked differences in soil characteristics for water holding capacity, (b) the loss of variability in hydraulic soil...

  4. Organic carbon stocks in permafrost-affected soils from Admiralty Bay, Antarctica

    Science.gov (United States)

    Simas, F.N.B.; Schaefer, C.E.G.R.; Mendonça, E.S.; Silva, I.R.; Santana, R.M.; Ribeiro, A.S.S.

    2007-01-01

    Recent works show that organic matter accumulation in some soils from coastal Antarctica is higher than previously expected. The objective of the present work was to estimate the organic C stocks for soils from maritime Antarctica. Cryosols from subpolar desert landscapes presented the lowest organic C stocks. Ornithogenic soils are the most important C reservoirs in terrestrial ecosystems in this part of Antarctica. Although these soils correspond to only 2.5 % of the ice-free areas at Admiralty Bay, they contain approximately 20 % of the estimated C stock. Most of the organic C in the studied soils is stored in the active layer but in some cases the C is also stored in the permafrost.

  5. Bacterial community structure and diversity in a black soil as affected by long-term fertilization

    Institute of Scientific and Technical Information of China (English)

    WEI Dan; YANG Qian; ZHANG Jun-Zheng; WANG Shuang; CHEN Xue-Li; ZHANG Xi-Lin; LI Wei-Qun

    2008-01-01

    Black soil (Mollisol) is one of the main soil types in northeastern China.Biolog and polymerase chain reactiondenaturing gradient gel electrophoresis (PCR-DGGE) methods were used to examine the influence of various fertilizer combinations on the structure and function of the bacterial community in a black soil collected from Harbin,Heilongjiang Province.Biolog results showed that substrate richness and catabolic diversity of the soil bacterial community were the greatest in the chemical fertilizer and chemical fertilizer+manure treatments.The metabolic ability of the bacterial community in the manure treatment was similar to the control.DGGE fingerprinting indicated similarity in the distribution of most 16S rDNA bands among all treatments,suggesting that microorganisms with those bands were stable and not influenced by fertilization.However,chemical fertilizer increased the diversity of soil bacterial community.Principal component analysis of Biolog and DGGE data revealed that the structure and function of the bacterial community were similar in the control and manure treatments,suggesting that the application of manure increased the soil microbial population,but had no effect on the bacterial community structure.Catabolic function was similar in the chemical fertilizer and chemical fertilizer+manure treatments,but the composition structure of the soil microbes differed between them.The use of chemical fertilizers could result in a decline in the catabolic activity of fast-growing or eutrophic bacteria.

  6. Carbon Sequestration in Soils Affected by Douglas Fir Reforestation in Apennines (Northern Italy

    Directory of Open Access Journals (Sweden)

    Giampaolo Di Biase

    2015-12-01

    Full Text Available Douglas fir reforestation plays an important role in Italian forest because no indigenous conifer has similar characteristics of productivity and timber quality. Few studies on physicochemical properties of soils under Douglas fire are noticeable. The aim of this work is to evaluate the organic C stock into soils under Douglas fir plantation in different selected areas. The areas of study are located in the North Apennine (Italy; Corno alle Scale (COR, Vallombrosa (VAL, Mulino Mengoni (MEN, respectively are chosen for the presence of Douglas fir reforestation of 60 years old. Two soil profiles for each area have been open and described. The pH value decreased along the profile depth. The organic C amount in organic layers was higher in Val and Men pedons than that determined in COR one. Higher amount of organic C were detected in organo-mineral horizons of Co pedons, highlighting a rapid turnover of soil organic matter. The C stock calculated in the first 30 cm of soil showed that the higher C amount is stored in highest altitudes profiles (COR6 and VAL6 than the other. The soil are classified as Lithic Dystrudepts in the highest altitudes (COR 6, 7 and VAL 6, 7, respectively while as Humic Dystrudepts in MEN (4 and 5 pedons. We conclude that no dangerous effects on soil quality of Douglas fir were investigated and they seem to be similar to those of native tree species, even if other different aspects should be investigated.

  7. Soil Quality Indicators as Affected by a Long Term Barley-Maize and Maize Cropping Systems

    Directory of Open Access Journals (Sweden)

    Anna Corsini

    2011-02-01

    Full Text Available Most soil studies aim a better characterization of the system through indicators. In the present study nematofauna and soil structure were chosen as indicators to be assess soil health as related to agricultural practices. The field research was carried out on the two fodder cropping systems continuous maize (CM, Zea mays L. and a 3-year rotation of silage-maize – silage-barley (Hordeum vulgare L. with Italian ryegrass (R3 and grain-maize maintained in these conditions for 18 years. Each crop system was submitted to two management options: 1 the high input level (H, done as a conventional tillage, 2 the low input level (L, where the tillage was replaced by harrowing and the manure was reduced by 30%. The effects of the two different cropping systems was assessed on soil nematofauna and soil physic parameters (structure or aggregate stability. Comparison was made of general composition, trophic structure and biodiversity of the nematofauna collected in both systems. Differences in nematode genera composition and distribution between the two systems were also recorded. The monoculture, compared to the three year rotation, had a negative influence on the nematofauna composition and its ecological succession. The Structural Stability Index (SSI values indicate that both the cropping systems had a negative effect on the aggregate stability. The results indicate that nematofauna can be used to assess the effects of cropping systems on soil ecosystem, and therefore be considered a good indicator of soil health to integrate information from different chemical or physical indicators.

  8. Soil Quality Indicators as Affected by a Long Term Barley-Maize and Maize Cropping Systems

    Directory of Open Access Journals (Sweden)

    Barbara Manachini

    2009-03-01

    Full Text Available Most soil studies aim a better characterization of the system through indicators. In the present study nematofauna and soil structure were chosen as indicators to be assess soil health as related to agricultural practices. The field research was carried out on the two fodder cropping systems continuous maize (CM, Zea mays L. and a 3-year rotation of silage-maize – silage-barley (Hordeum vulgare L. with Italian ryegrass (R3 and grain-maize maintained in these conditions for 18 years. Each crop system was submitted to two management options: 1 the high input level (H, done as a conventional tillage, 2 the low input level (L, where the tillage was replaced by harrowing and the manure was reduced by 30%. The effects of the two different cropping systems was assessed on soil nematofauna and soil physic parameters (structure or aggregate stability. Comparison was made of general composition, trophic structure and biodiversity of the nematofauna collected in both systems. Differences in nematode genera composition and distribution between the two systems were also recorded. The monoculture, compared to the three year rotation, had a negative influence on the nematofauna composition and its ecological succession. The Structural Stability Index (SSI values indicate that both the cropping systems had a negative effect on the aggregate stability. The results indicate that nematofauna can be used to assess the effects of cropping systems on soil ecosystem, and therefore be considered a good indicator of soil health to integrate information from different chemical or physical indicators.

  9. Factors affecting spatial variation of polycyclic aromatic hydrocarbons in surface soils in North China Plain.

    Science.gov (United States)

    Wang, Xilong; Zuo, Qian; Duan, Yonghong; Liu, Wenxin; Cao, Jun; Tao, Shu

    2012-10-01

    The spatial variation in concentrations of 16 polycyclic aromatic hydrocarbons (PAHs) in surface soils in the North China Plain and the influential factors were examined in the present study. High concentrations of the sum of 16 PAHs (∑PAH(16) ) appeared in cities and their surrounding areas. Emissions and soil organic carbon (SOC) content significantly regulated spatial differentiation of PAH contamination in soils in the study area. Compared with emissions, concentrations of individual and total PAHs in soils were more closely controlled by the SOC content. Furthermore, concentrations of PAH species with lower molecular weight (e.g., two- or three-ring) in surface soils were more strongly correlated with the SOC content in comparison with those of higher molecular weight (e.g., five- or six-ring), mainly because of their higher saturated vapor pressure, thus higher mobility. The spatial variation of PAH species in soils in the North China Plain tended to be larger with increasing benzene ring numbers, and the difference in physicochemical properties of PAH species determined their distinct spatial distribution characteristics. The present study highlights the relative importance of emissions and SOC content in spatial variation of PAHs and the dependence of the spatial distribution characteristics of PAH species in surface soils on their physicochemical properties at a regional scale. Results of the present work are helpful for regional risk assessment of the contaminants tested. PMID:22847656

  10. Bioaccumulation of thallium in an agricultural soil as affected by solid-phase association

    Science.gov (United States)

    Vaněk, Aleš; Grösslová, Zuzana; Mihaljevič, Martin

    2016-04-01

    The work focused on the biogeochemical behavior of synthetic Tl modified phases, namely birnessite, ferrihydrite, and calcite, in a neutral soil Leptosol. The data presented here clearly demonstrate a strong relationship between the mineralogical position of Tl in the soil and its uptake by the studied plant (Sinapis alba L.). All tested Tl phases behaved as potential Tl sources in the rhizosphere, with a maximum for ferrihydrite and minimum for birnessite. Therefore, it can be concluded that Mn(III,IV) oxides, if present in the soil system, may reduce biological uptake of Tl to a substantial degree, including the case of Tl-accumulating species (i.e., Brassicaceae). It was proven that even Tl-enriched calcite present in the carbonate-rich soil is an important precursor for further contaminant mobilization, despite its relative resistance to degradation. Our data indicate that the fate of secondary Tl phases in the rhizosphere might be significantly influenced by the pH of the soil matrix, i.e., soils with lower pHs reduce their stability, making them more susceptible to further degradation by root exudates. Bulk soil mineralogy and the content and quality of SOM are thus suggested to be critical parameters controlling the bioaccumulation potential for Tl. This research was supported by the Czech Science Foundation (grant no. 14-01866S).

  11. Fertilization Affects Biomass Production of Suaeda salsa and Soil Organic Carbon Pool in East Coastal Region of China

    Institute of Scientific and Technical Information of China (English)

    MENG Qing-feng; YANG Jing-song; YAO Rong-jiang; LIU Guang-ming; YU Shi-peng

    2013-01-01

    Land use practice significantly affects soil properties. Soil is a major sink for atmospheric carbon, and soil organic carbon (SOC) is considered as an essential indicator of soil quality. The objective of this study was to assess the effects of N and P applied to Suaeda salsa on biomass production, SOC concentration, labile organic carbon (LOC) concentration, SOC pool and carbon management index (CMI) as well as the effect of the land use practice on soil quality of coastal tidal lands in east coastal region of China. The study provided relevant references for coastal exploitation, tidal land management and related study in other countries and regions. The field experiment was laid out in a randomized complete block design, consisting of four N-fertilization rates (0 (N0), 60 (N1), 120 (N2) and 180 kg ha-1 (N3)), three P-fertilization rates (0 (P0), 70 (P1) and 105 kg ha-1 (P2)) and bare land without vegetation. N and P applied to S. salsa on coastal tidal lands significantly affected biomass production (above-ground biomass and roots), bulk density (ρb), available N and P, SOC, LOC, SOC pool and CMI. Using statistical analysis, significantly interactions in N and P were observed for biomass production and the dominant factor for S. salsa production was N in continuous 2-yr experiments. There were no significant interactions between N and P for SOC concentration, LOC concentration and SOC pool. However, significant interaction was obtained for CMI at the 0-20 cm depth and N played a dominant role in the variation of CMI. There were significant improvements for soil measured attributes and parameters, which suggested that increasing the rates of N and P significantly decreasedρb at the 0-20 cm depth and increased available N and P, SOC, LOC, SOC pool as well as CMI at both the 0-20 and 20-40 cm depth, respectively. By correlation analysis, there were significantly positive correlations between biomass (above-ground biomass and roots) and SOC as well as LOC in

  12. Disturbace events affect interactions amoung four different hydrolytic enzymes in arid soils

    Science.gov (United States)

    Warnock, D.; Litvak, M. E.; Sinsabaugh, R. L.

    2014-12-01

    Global change processes are significantly altering key ecosystem processes in arid ecosystems. Such phenomena are also likely to influence the functional behaviors of resident soil microbial communities, and the magnitude of biogeochemical processes, including, soil organic matter turnover, soil nutrient cycling and soil carbon storage. To assess the aggregate influences of tree mortality, woody plant encroachment, fire, and drought, on soil microbial community activity and functionality, we collected soil samples from beneath plant canopies, and from adjacent bare soils. We sampled from two different piñon-juniper woodland sites. One had many dead piñons, while the other did not, a burned and an unburned grassland, a shrub site, a shrub/grass ecotone, and a juniper savannah. We analyzed eleven soil physicochemical properties, none of which showed any significant trends across our different sampling locations, fungal biomass, and the activities of alanine aminopeptidase, alkaline phosphatase, β-D-glucosidase, and β-N-acetyl glucosaminidase (NAGase). One-wayANOVA results showed that enzyme activity patterns were largely consistent across field sites, while multivariate analyses showed a variety of interactive responses by individual enzymes,with respect to disturbance events. For example, at the burned grassland, all four enzymes activities were strongly correlated, while at the unburned grassland, relationships between peptidase:NAGase and peptidase:β-D-glucosidase were weak, with both R2 ≤ 0.08. Additionally in the shrub-grass ecotone, the correlation among enzyme activities and soil nutrient availabilities were up to 8x stronger than those observed at either grassland site. These results show that disturbance alters the number of functional dimensions needed to describe enzymatic C, N and P acquisition, which may be an indication of shifts in microbial community organization.

  13. Changes of the soil environment affected by fly ash dumping site of the electric power plant

    Science.gov (United States)

    Weber, Jerzy; Gwizdz, Marta; Jamroz, Elzbieta; Debicka, Magdalena; Kocowicz, Andrzej

    2014-05-01

    In this study the effect of fly ash dumping site of the electric power plant on the surrounding soil environment was investigated. The fly ash dumping site collect wastes form brown coal combustion of Belchatow electric power station, central Poland. The dumping site is surrounding by forest, where pine trees overgrow Podzols derived from loose quartz sands. The soil profiles under study were located at a distance of 50, 100, 400 and 500 m from the dumping site, while control profiles were located 8 km away from the landfill. In all horizons of soil profiles the mpain hysico-chemical and chemical properties were determined. The humic substances were extracted from ectohumus horizons by Shnitzer's method, purified using XAD resin and freeze-dried. The fulvic acids were passed through a cation exchange column and freeze-dried. Optical density, elemental composition and atomic ratios were determined in the humic and fulvic acids. Organic carbon by KMnO4 oxidation was also determined in the organic soil horizons. The fly ash from the landfill characterized by high salinity and strong alkaline reaction (pH=10), which contributed significantly to the changes of the pH values in soils horizons. The alkalization of soils adjacent to the landfill was found, which manifested in increasing of pH values in the upper soil horizons. The impact of the landfill was also noted in the changes of the soil morphology of Podzols analysed. As a result of the alkalization, Bhs horizons have been converted into a Bs horizons. Leaching of low molecular humus fraction - typical for podzolization - has been minimized as a result of pH changes caused by the impact of the landfill, and originally occurring humic substances in the Bhs horizon (present in the control profiles) have been probably transported out of the soil profile and then into the groundwater.

  14. Initial water repellency affected organic matter depletion rates of manure amended soils in Sri Lanka

    Directory of Open Access Journals (Sweden)

    Leelamanie D.A.L.

    2014-12-01

    Full Text Available The wetting rate of soil is a measure of water repellency, which is a property of soils that prevents water from wetting or penetrating into dry soil. The objective of the present research was to examine the initial water repellency of organic manure amended soil, and its relation to the soil organic matter (SOM depletion rates in the laboratory. Soil collected from the Wilpita natural forest, Sri Lanka, was mixed with organic manure to prepare soil samples with 0, 5, 10, 25, and 50% organic manure contents. Locally available cattle manure (CM, goat manure (GM, and Casuarina equisetifolia leaves (CE were used as the organic manure amendments. Organic matter content of soils was measured in 1, 3, 7, 14, and 30 days intervals under the laboratory conditions with 74±5% relative humidity at 28±1°C. Initial water repellency of soil samples was measured as the wetting rates using the water drop penetration time (WDPT test. Initial water repellency increased with increasing SOM content showing higher increasing rate for hydrophobic CE amended samples compared with those amended with CM and GM. The relation between water repellency and SOM content was considered to be governed by the original hydrophobicities of added manures. The SOM contents of all the soil samples decreased with the time to reach almost steady level at about 30 d. The initial SOM depletion rates were negatively related with the initial water repellency. However, all the CE amended samples initially showed prominent low SOM depletion rates, which were not significantly differed with the amended manure content or the difference in initial water repellency. It is explicable that the original hydrophobicity of the manure as well has a potentially important effect on initiation of SOM decomposition. In contrast, the overall SOM depletion rate can be attributed to the initial water repellency of the manure amended sample, however, not to the original hydrophobicity of the amended manure

  15. Transport and reaction processes affecting the attenuation of landfill gas in cover soils

    DEFF Research Database (Denmark)

    Molins, S.; Mayer, K.U.; Scheutz, Charlotte;

    2008-01-01

    Methane and trace organic gases produced in landfill waste are partly oxidized in the top 40 cm of landfill cover soils under aerobic conditions. The balance between the oxidation of landfill gases and the ingress of atmospheric oxygen into the soil cover determines the attenuation of emissions of...... emission to the atmosphere. Oxygen supply into the soil column is driven exclusively by diffusion, whereas advection outward offsets part of the diffusive contribution. In the reaction zone, methane consumption reduces the pressure gradient, further decreasing the significance of advection near the top of...

  16. Soil moisture variations affect short-term plant-microbial competition for ammonium, glycine, and glutamate

    OpenAIRE

    Månsson, Katarina F; Olsson, Magnus O; Falkengren-Grerup, Ursula; Bengtsson, Göran

    2014-01-01

    We tested whether the presence of plant roots would impair the uptake of ammonium ( ), glycine, and glutamate by microorganisms in a deciduous forest soil exposed to constant or variable moisture in a short-term (24-h) experiment. The uptake of 15NH4 and dual labeled amino acids by the grass Festuca gigantea L. and soil microorganisms was determined in planted and unplanted soils maintained at 60% WHC (water holding capacity) or subject to drying and rewetting. The experiment used a design by...

  17. Dissipation and effects of tricyclazole on soil microbial communities and rice growth as affected by amendment with alperujo compost.

    Science.gov (United States)

    García-Jaramillo, M; Redondo-Gómez, S; Barcia-Piedras, J M; Aguilar, M; Jurado, V; Hermosín, M C; Cox, L

    2016-04-15

    The presence of pesticides in surface and groundwater has grown considerably in the last decades as a consequence of the intensive farming activity. Several studies have shown the benefits of using organic amendments to prevent losses of pesticides from runoff or leaching. A particular soil from the Guadalquivir valley was placed in open air ponds and amended at 1 or 2% (w/w) with alperujo compost (AC), a byproduct from the olive oil industry. Tricyclazole dissipation, rice growth and microbial diversity were monitored along an entire rice growing season. An increase in the net photosynthetic rate of Oryza sativa plants grown in the ponds with AC was observed. These plants produced between 1100 and 1300kgha(-1) more rice than plants from the unamended ponds. No significant differences were observed in tricyclazole dissipation, monitored for a month in soil, surface and drainage water, between the amended and unamended ponds. The structure and diversity of bacteria and fungi communities were also studied by the use of the polymerase chain reaction denaturing gel electrophoresis (PCR-DGGE) from DNA extracted directly from soil samples. The banding pattern was similar for all treatments, although the density of bands varied throughout the time. Apparently, tricyclazole did not affect the structure and diversity of bacteria and fungi communities, and this was attributed to its low bioavailability. Rice cultivation under paddy field conditions may be more efficient under the effects of this compost, due to its positive effects on soil properties, rice yield, and soil microbial diversity. PMID:26849328

  18. Clay mineralogical evidence of a bioclimatically-affected soil, Rouge River basin, South-Central Ontario, Canada

    Science.gov (United States)

    Mahaney, W. C.

    2015-01-01

    Holocene soils in drainage basins of South-Central Ontario, Canada, are generally Fluvisols (Entisols) in floodplains transitioning to Brunisols (Inceptisols), Luvisols (Alfisols) and Podzols (Spodosols) in older terraces and in the glaciated tableland. A single landslide sourced from the highest fluvial terrace in the Rouge basin, with a rubble drop of ~ 12 m emplaced a lobe-shaped mass of reworked stream gravel, glaciolacustrine sediment and till, emplaced approximately 6 m above mean water level at a height roughly equivalent to previously dated mid-Holocene terraces and soils. Clay mineralogy of the soil formed in this transported regolith produced the usual semi-detrital/pedogenic distribution of 1:1 (Si:Al = 1:1), 2:1 and 2:1:1 clay minerals as well as primary minerals consisting of plagioclase feldspar, quartz, mica and calcite. Unexpectedly, the presence of moderate amounts of Ca-smectite in the Bk and Ck horizons, relative to a clay-mineral depleted parent material (Cuk), argues for a soil hydrological change affecting the wetting depth in the deposit. The presence of the uncommon 'maidenhair fern' (Adiantum pedantum) in the mass wasted deposit, a plant capable of high evapotranspiration, is interpreted as producing a bioclimatic disruption limiting soil water penetration to near root depth (wetting depth), thus producing a clay mineral anomaly.

  19. Spatial pattern formation of microbes at the soil microscale affect soil C and N turnover in an individual-based microbial community model

    Science.gov (United States)

    Kaiser, Christina; Evans, Sarah; Dieckmann, Ulf; Widder, Stefanie

    2016-04-01

    At the μm-scale, soil is a highly structured and complex environment, both in physical as well as in biological terms, characterized by non-linear interactions between microbes, substrates and minerals. As known from mathematics and theoretical ecology, spatial structure significantly affects the system's behaviour by enabling synergistic dynamics, facilitating diversity, and leading to emergent phenomena such as self-organisation and self-regulation. Such phenomena, however, are rarely considered when investigating mechanisms of microbial soil organic matter turnover. Soil organic matter is the largest terrestrial reservoir for organic carbon (C) and nitrogen (N) and plays a pivotal role in global biogeochemical cycles. Still, the underlying mechanisms of microbial soil organic matter buildup and turnover remain elusive. We explored mechanisms of microbial soil organic matter turnover using an individual-based, stoichiometrically and spatially explicit computer model, which simulates the microbial de-composer system at the soil microscale (i.e. on a grid of 100 x 100 soil microsites). Soil organic matter dynamics in our model emerge as the result of interactions among individual microbes with certain functional traits (f.e. enzyme production rates, growth rates, cell stoichiometry) at the microscale. By degrading complex substrates, and releasing labile substances microbes in our model continusly shape their environment, which in turn feeds back to spatiotemporal dynamics of the microbial community. In order to test the effect of microbial functional traits and organic matter input rate on soil organic matter turnover and C and N storage, we ran the model into steady state using continuous inputs of fresh organic material. Surprisingly, certain parameter settings that induce resource limitation of microbes lead to regular spatial pattern formation (f.e. moving spiral waves) of microbes and substrate at the μm-scale at steady-state. The occurrence of these

  20. Changes in canopy structure and ant assemblages affect soil ecosystem variables as a foundation species declines:Ecosphere

    OpenAIRE

    Kendrick, Joseph A.; Ribbons, Relena Rose; Classen, Aimee Taylor; Ellison, Aaron M.

    2015-01-01

    The decline of Tsuga canadensis (eastern hemlock)?a foundation tree species?due to infestation by Adelges tsugae (hemlock woolly adelgid) or its complete removal from a stand by salvage logging dramatically affects associated faunal assemblages. Among these assemblages, species composition (richness and abundance) of ants increases rapidly as T. canadensis is lost from the stands. Because ants live and forage at the litter-soil interface, we hypothesized that environmental changes caused by h...

  1. Confocal Raman microspectroscopy reveals a convergence of the chemical composition in methanogenic archaea from a Siberian permafrost-affected soil

    OpenAIRE

    Serrano, P; Hermelink, A.; Lasch, P.; de Vera, J.-P.; König, N.; Burckhardt, O.; Wagner, D.

    2015-01-01

    Methanogenic archaea are widespread anaerobic microorganisms responsible for the 25 production of biogenic methane. Several new species of psychrotolerant methanogenic archaea were recently isolated from a permafrost-affected soil in the Lena delta (Siberia, Russia), showing an exceptional resistance against desiccation, osmotic stress, low temperatures, starvation, UV and ionizing radiation when compared to methanogens from non-permafrost environments. To gain a deeper insight into the diffe...

  2. Soil remediation in the areas affected by space-rocket industry activities in the Central Kazakhstan

    International Nuclear Information System (INIS)

    The study has been carried out to demonstrate that the modified carbon-mineral sorbents based on the schungite material can be effectively used for decontamination of soil polluted by liquid rocket fuel components and its decomposition products.

  3. Bacterial diversity in Greenlandic soils as affected by potato cropping and inorganic versus organic fertilization

    DEFF Research Database (Denmark)

    Michelsen, Charlotte Frydenlund; Pedas, Pai Rosager; Glaring, Mikkel Andreas;

    2014-01-01

    limited research has been performed on the effects of these treatments on bacterial communities in Arctic and Subarctic agricultural soils. The major objective of this study was to investigate the short-term impact of conventional (NPK) and organic (sheep manure supplemented with nitrogen) fertilizer...... treatments on bacterial diversity, nutrient composition and crop yield in two Greenlandic agricultural soils. An effect of fertilizer was found on soil and plant nutrient levels and on crop yields. Pyrosequencing of 16S rRNA gene sequences did not reveal any major changes in the overall bacterial community...... composition as a result of different fertilizer treatments, indicating a robust microbial community in these soils. In addition, differences in nutrient levels, crop yields and bacterial abundances were found between the two field sites and the two experimental growth seasons, which likely reflect differences...

  4. Changes in canopy structure and ant assemblages affect soil ecosystem variables as a foundation species declines

    DEFF Research Database (Denmark)

    Kendrick, Joseph A.; Ribbons, Relena Rose; Classen, Aimee Taylor;

    2015-01-01

    (richness and abundance) of ants increases rapidly as T. canadensis is lost from the stands. Because ants live and forage at the litter-soil interface, we hypothesized that environmental changes caused by hemlock loss (e.g., increased light and warmth at the forest floor, increased soil pH) and shifts in...... ant species composition would interact to alter soil ecosystem variables. In the Harvard Forest Hemlock Removal Experiment (HF-HeRE), established in 2003, T. canadensis in large plots were killed in place or logged and removed to mimic adelgid infestation or salvage harvesting, respectively. In 2006......, we built ant exclosure subplots within all of the canopy manipulation plots to examine direct and interactive effects of canopy change and ant assemblage composition on soil and litter variables. Throughout HF-HeRE, T. canadensis was colonized by the adelgid in 2009, and the infested trees are now...

  5. Soil tensile strength as affected by time, water content and bulk density

    Directory of Open Access Journals (Sweden)

    J. Pytka

    1995-09-01

    Full Text Available We investigated the effect of soil water conditions and soil compaction on the age-hardening process of loamy sand and silty loamy sand in relation to the tensile strength. Soil samples from Germany (loamy sand and Poland (silty loamy sand were moulded at water contents 10 %, 15 %, 20 % and compacted up to 1.35, 1.45, 1.55g/cm3. The samples were stored at constant water content. At intervals after moulding, the tensile strengths of the moist samples were measured with the indirect tension (Brazilian test. The maximum aging time was 10 days. With increasing time the soils became stronger at the same water content. The higher the initial water content the less pronounced was the strength increase with time. Furthermore, increase in bulk density resulted in higher values of tensile strength. Two different mechanisms of age-hardening could be identified.

  6. Nitrogen Addition as a Result of Long-Term Root Removal Affects Soil Organic Matter Dynamics

    Science.gov (United States)

    Crow, S. E.; Lajtha, K.

    2004-12-01

    A long-term field litter manipulation site was established in a mature coniferous forest stand at the H.J. Andrews Experimental Forest, OR, USA in 1997 in order to address how detrital inputs influence soil organic matter formation and accumulation. Soils at this site are Andisols and are characterized by high carbon (C) and low nitrogen (N) contents, due largely to the legacy of woody debris and extremely low atmospheric N deposition. Detrital treatments include trenching to remove roots, doubling wood and needle litter, and removing aboveground litter. In order to determine whether five years of detrital manipulation had altered organic matter quantity and lability at this site, soil from the top 0-5 cm of the A horizon was density fractionated to separate the labile light fraction (LF) from the more recalcitrant mineral soil in the heavy fraction (HF). Both density fractions and whole soils were incubated for one year in chambers designed such that repeated measurements of soil respiration and leachate chemistry could be made. Trenching resulted in the removal of labile root inputs from root exudates and turnover of fine roots and active mycorrhizal communities as well as an increase of available N by removing plant uptake. Since 1999, soil solution chemistry from tension lysimeters has shown greater total N and dissolved organic nitrogen (DON) flux and less dissolved organic carbon (DOC) flux to stream flow in the trenched plots relative to the other detrital treatments. C/N ratio and C content of both light and heavy fractions from the trenched plots were greater than other detrital treatments. In the lab incubation, over the course of a year C mineralization from these soils was suppressed. Cumulative DOC losses and CO2 efflux both were significantly less in soils from trenched plots than in other detrital treatments including controls. After day 150 of the incubation, leachates from the HF of plots with trenched treatments had a DOC/DON ratio significantly

  7. Land-use systems affect Archaeal community structure and functional diversity in western Amazon soils

    OpenAIRE

    Acácio Aparecido Navarrete; Rodrigo Gouvêa Taketani; Lucas William Mendes; Fabiana de Souza Cannavan; Fatima Maria de Souza Moreira; Siu Mui Tsai

    2011-01-01

    The study of the ecology of soil microbial communities at relevant spatial scales is primordial in the wide Amazon region due to the current land use changes. In this study, the diversity of the Archaea domain (community structure) and ammonia-oxidizing Archaea (richness and community composition) were investigated using molecular biology-based techniques in different land-use systems in western Amazonia, Brazil. Soil samples were collected in two periods with high precipitation (March 2008 a...

  8. Microbial Functional Diversity, Biomass and Activity as Affected by Soil Surface Mulching in a Semiarid Farmland.

    Science.gov (United States)

    Shen, Yufang; Chen, Yingying; Li, Shiqing

    2016-01-01

    Mulching is widely used to increase crop yield in semiarid regions in northwestern China, but little is known about the effect of different mulching systems on the microbial properties of the soil, which play an important role in agroecosystemic functioning and nutrient cycling. Based on a 4-year spring maize (Zea mays L.) field experiment at Changwu Agricultural and Ecological Experimental Station, Shaanxi, we evaluated the responses of soil microbial activity and crop to various management systems. The treatments were NMC (no mulching with inorganic N fertilizer), GMC (gravel mulching with inorganic N fertilizer), FMC (plastic-film mulching with inorganic N fertilizer) and FMO (plastic-film mulching with inorganic N fertilizer and organic manure addition). The results showed that the FMO soil had the highest contents of microbial biomass carbon and nitrogen, dehydrogenase activity, microbial activity and Shannon diversity index. The relative use of carbohydrates and amino acids by microbes was highest in the FMO soil, whereas the relative use of polymers, phenolic compounds and amines was highest in the soil in the NMC soil. Compared with the NMC, an increased but no significant trend of biomass production and nitrogen accumulation was observed under the GMC treatment. The FMC and FMO led a greater increase in biomass production than GMC and NMC. Compare with the NMC treatment, FMC increased grain yield, maize biomass and nitrogen accumulation by 62.2, 62.9 and 86.2%, but no significant difference was found between the FMO and FMC treatments. Some soil biological properties, i.e. microbial biomass carbon, microbial biomass nitrogen, being sensitive to the mulching and organic fertilizer, were significant correlated with yield and nitrogen availability. Film mulching over gravel mulching can serve as an effective measure for crop production and nutrient cycling, and plus organic fertilization additions may thus have improvements in the biological quality of the

  9. Metal Concentrations in Soil Paste Extracts as Affected by Extraction Ratio

    OpenAIRE

    Filip M.G. Tack; Nic Dezillie; Verloo, Marc G.

    2002-01-01

    Saturated paste extracts are sometimes used to estimate metal levels in the soil solution. To assess the significance of heavy-metal concentrations measured in saturation extracts, soil paste extracts were prepared with distilled water in amounts ranging from 60–200% of the moisture content at saturation. Trace metals behaved as if a small pool consistently was dissolved independent of the extraction ratio applied. Metal concentrations in the solution hence were not buffered by the solid phas...

  10. Microbial Functional Diversity, Biomass and Activity as Affected by Soil Surface Mulching in a Semiarid Farmland

    Science.gov (United States)

    Shen, Yufang; Chen, Yingying; Li, Shiqing

    2016-01-01

    Mulching is widely used to increase crop yield in semiarid regions in northwestern China, but little is known about the effect of different mulching systems on the microbial properties of the soil, which play an important role in agroecosystemic functioning and nutrient cycling. Based on a 4-year spring maize (Zea mays L.) field experiment at Changwu Agricultural and Ecological Experimental Station, Shaanxi, we evaluated the responses of soil microbial activity and crop to various management systems. The treatments were NMC (no mulching with inorganic N fertilizer), GMC (gravel mulching with inorganic N fertilizer), FMC (plastic-film mulching with inorganic N fertilizer) and FMO (plastic-film mulching with inorganic N fertilizer and organic manure addition). The results showed that the FMO soil had the highest contents of microbial biomass carbon and nitrogen, dehydrogenase activity, microbial activity and Shannon diversity index. The relative use of carbohydrates and amino acids by microbes was highest in the FMO soil, whereas the relative use of polymers, phenolic compounds and amines was highest in the soil in the NMC soil. Compared with the NMC, an increased but no significant trend of biomass production and nitrogen accumulation was observed under the GMC treatment. The FMC and FMO led a greater increase in biomass production than GMC and NMC. Compare with the NMC treatment, FMC increased grain yield, maize biomass and nitrogen accumulation by 62.2, 62.9 and 86.2%, but no significant difference was found between the FMO and FMC treatments. Some soil biological properties, i.e. microbial biomass carbon, microbial biomass nitrogen, being sensitive to the mulching and organic fertilizer, were significant correlated with yield and nitrogen availability. Film mulching over gravel mulching can serve as an effective measure for crop production and nutrient cycling, and plus organic fertilization additions may thus have improvements in the biological quality of the

  11. Biofumigation using a wild Brassica oleracea accession with high glucosinolate content affects beneficial soil

    OpenAIRE

    Zuluaga, D.L.; Ommen Kloeke van, A.E.E.; Verkerk, R.; Röling, W.F.M.; Ellers, J.; Roelofs, D.; Aarts, M.G.M.

    2015-01-01

    Aims This study explores the biofumigation effects of glucosinolate (GSL) containing Brassica oleracea plant material on beneficial, non-target soil organisms, and aims to relate those effects to differences in GSL profiles. Methods Leaf material of purple sprouting broccoli ‘Santee’, Savoy cabbage ‘Wintessa’, and the wild B. oleracea accession Winspit was analysed for GSL production and used for biofumigation experiments on the beneficial soil invertebrates, Folsomia candida (springtail) and...

  12. Assessment of heavy metals pollution in sulphide mine affected-soils of madrid, central spain

    OpenAIRE

    Torres, M.; Recio Vázquez, Lorena; Carral, Pilar; Álvarez, Ana María

    2011-01-01

    The uncontrolled extraction of mineral resources is considered one of the major anthropogenic sources of soil pollution. In Spain, exploitation of metallic mineral deposits and its subsequent abandonment in last decades has lead to significant environmental hazard for natural systems. In this research, potentially contaminated soils surrounding an old chalcopyrite mine district in Madrid (Central Spain) have been studied. The focus is to assess the degree of pollution by heavy metals and othe...

  13. Microbial Functional Diversity, Biomass and Activity as Affected by Soil Surface Mulching in a Semiarid Farmland.

    Directory of Open Access Journals (Sweden)

    Yufang Shen

    Full Text Available Mulching is widely used to increase crop yield in semiarid regions in northwestern China, but little is known about the effect of different mulching systems on the microbial properties of the soil, which play an important role in agroecosystemic functioning and nutrient cycling. Based on a 4-year spring maize (Zea mays L. field experiment at Changwu Agricultural and Ecological Experimental Station, Shaanxi, we evaluated the responses of soil microbial activity and crop to various management systems. The treatments were NMC (no mulching with inorganic N fertilizer, GMC (gravel mulching with inorganic N fertilizer, FMC (plastic-film mulching with inorganic N fertilizer and FMO (plastic-film mulching with inorganic N fertilizer and organic manure addition. The results showed that the FMO soil had the highest contents of microbial biomass carbon and nitrogen, dehydrogenase activity, microbial activity and Shannon diversity index. The relative use of carbohydrates and amino acids by microbes was highest in the FMO soil, whereas the relative use of polymers, phenolic compounds and amines was highest in the soil in the NMC soil. Compared with the NMC, an increased but no significant trend of biomass production and nitrogen accumulation was observed under the GMC treatment. The FMC and FMO led a greater increase in biomass production than GMC and NMC. Compare with the NMC treatment, FMC increased grain yield, maize biomass and nitrogen accumulation by 62.2, 62.9 and 86.2%, but no significant difference was found between the FMO and FMC treatments. Some soil biological properties, i.e. microbial biomass carbon, microbial biomass nitrogen, being sensitive to the mulching and organic fertilizer, were significant correlated with yield and nitrogen availability. Film mulching over gravel mulching can serve as an effective measure for crop production and nutrient cycling, and plus organic fertilization additions may thus have improvements in the biological

  14. Evaluation of a WorldView-2 image for soil salinity monitoring in a moderately affected irrigated area

    Science.gov (United States)

    Vermeulen, Divan; van Niekerk, Adriaan

    2016-04-01

    Conventional methods for monitoring salt accumulation within irrigation schemes involve regular field visits to collect soil samples for laboratory analysis. Remote sensing has been proposed as a less time-consuming, more cost-effective alternative as it provides imagery covering large areas throughout the year. This study evaluated the efficacy of very high resolution (VHR) WorldView-2 imagery to map areas affected by salt accumulation. Classifications based on thresholds obtained from Jeffries-Matusita distance, regression modeling, classification and regression trees, as well as supervised classification approaches, were evaluated for discriminating between salt-affected and unaffected soils in Vaalharts, South Africa. The WorldView-2 bands were supplemented with salinity indices (SIs), principal components, and texture measures to increase the number of predictive variables. In situ soil samples were used for model development, classifier training, and accuracy assessment. The results showed that a simple threshold implemented on a normalized difference SI was the most successful in separating classes, with an overall accuracy of 80%. The findings suggest that VHR satellite imagery holds much potential for monitoring salt accumulation, but more research is needed to investigate why the classification results tend to overestimate salt-affected areas. More work is also needed to evaluate the transferability of the techniques to other irrigation schemes.

  15. Dynamics of aggregate stability and soil organic C distribution as affected by climatic aggressiveness: a mesocosm approach

    Science.gov (United States)

    Pellegrini, Sergio; Elio Agnelli, Alessandro; Costanza Andrenelli, Maria; Barbetti, Roberto; Castelli, Fabio; Costantini, Edoardo A. C.; Lagomarsino, Alessandra; Pasqui, Massimiliano; Tomozeiu, Rodica; Razzaghi, Somayyeh; Vignozzi, Nadia

    2014-05-01

    changed at the end of the trial, depending of soil types. In CAS and MED a decrease of C content was observed in fractions larger than 0.250 mm, while an accumulation occurred only in CAS microaggregates. BOV showed a singular pattern, with an increase of organic C in all fractions. In this site an improvement of aggregation, involving the coarser fractions, seems to have been favoured during the experiment. Overall, the imposed climate did not affect significantly these trends, except in CAS, where TYP and SIM climates showed an increase of macroaggregates and their C concentration. Soil pedoclimatic characteristics showed to be the main factors affecting C and aggregates dynamics in this mesocosm experiment.

  16. Biochar and manure affect calcareous soil and corn silage nutrient concentrations and uptake.

    Science.gov (United States)

    Lentz, R D; Ippolito, J A

    2012-01-01

    Carbon-rich biochar derived from the pyrolysis of biomass can sequester atmospheric CO, mitigate climate change, and potentially increase crop productivity. However, research is needed to confirm the suitability and sustainability of biochar application to different soils. To an irrigated calcareous soil, we applied stockpiled dairy manure (42 Mg ha dry wt) and hardwood-derived biochar (22.4 Mg ha), singly and in combination with manure, along with a control, yielding four treatments. Nitrogen fertilizer was applied when needed (based on preseason soil test N and crop requirements) in all plots and years, with N mineralized from added manure included in this determination. Available soil nutrients (NH-N; NO-N; Olsen P; and diethylenetriaminepentaacetic acid-extractable K, Mg, Na, Cu, Mn, Zn, and Fe), total C (TC), total N (TN), total organic C (TOC), and pH were evaluated annually, and silage corn nutrient concentration, yield, and uptake were measured over two growing seasons. Biochar treatment resulted in a 1.5-fold increase in available soil Mn and a 1.4-fold increase in TC and TOC, whereas manure produced a 1.2- to 1.7-fold increase in available nutrients (except Fe), compared with controls. In 2009 biochar increased corn silage B concentration but produced no yield increase; in 2010 biochar decreased corn silage TN (33%), S (7%) concentrations, and yield (36%) relative to controls. Manure produced a 1.3-fold increase in corn silage Cu, Mn, S, Mg, K, and TN concentrations and yield compared with the control in 2010. The combined biochar-manure effects were not synergistic except in the case of available soil Mn. In these calcareous soils, biochar did not alter pH or availability of P and cations, as is typically observed for acidic soils. If the second year results are representative, they suggest that biochar applications to calcareous soils may lead to reduced N availability, requiring additional soil N inputs to maintain yield targets. PMID:22751045

  17. Plant species diversity affects soil-atmosphere fluxes of methane and nitrous oxide.

    Science.gov (United States)

    Niklaus, Pascal A; Le Roux, Xavier; Poly, Franck; Buchmann, Nina; Scherer-Lorenzen, Michael; Weigelt, Alexandra; Barnard, Romain L

    2016-07-01

    Plant diversity effects on ecosystem functioning can potentially interact with global climate by altering fluxes of the radiatively active trace gases nitrous oxide (N2O) and methane (CH4). We studied the effects of grassland species richness (1-16) in combination with application of fertilizer (nitrogen:phosphorus:potassium = 100:43.6:83 kg ha(-1) a(-1)) on N2O and CH4 fluxes in a long-term field experiment. Soil N2O emissions, measured over 2 years using static chambers, decreased with species richness unless fertilizer was added. N2O emissions increased with fertilization and the fraction of legumes in plant communities. Soil CH4 uptake, a process driven by methanotrophic bacteria, decreased with plant species numbers, irrespective of fertilization. Using structural equation models, we related trace gas fluxes to soil moisture, soil inorganic N concentrations, nitrifying and denitrifying enzyme activity, and the abundance of ammonia oxidizers, nitrite oxidizers, and denitrifiers (quantified by real-time PCR of gene fragments amplified from microbial DNA in soil). These analyses indicated that plant species richness increased soil moisture, which in turn increased N cycling-related activities. Enhanced N cycling increased N2O emission and soil CH4 uptake, with the latter possibly caused by removal of inhibitory ammonium by nitrification. The moisture-related indirect effects were surpassed by direct, moisture-independent effects opposite in direction. Microbial gene abundances responded positively to fertilizer but not to plant species richness. The response patterns we found were statistically robust and highlight the potential of plant biodiversity to interact with climatic change through mechanisms unrelated to carbon storage and associated carbon dioxide removal. PMID:27038993

  18. Radioisotopics and Physicochemical Investigation to Assess Soil Erosion Affecting Spanish Orchard Fields

    International Nuclear Information System (INIS)

    Soil degradation is a major agro-environmental issue under Mediterranean climatic conditions. In Spain, 40% of the territory is under severe to very severe human induced land degradation, especially in the southern part of the country. While soil erosion studies in these regions have mainly been undertaken using conventional techniques such as modelling, in this preliminary study complementary nuclear techniques (naturally occurring radionuclides (NOR), such as 40K, 226Ra and 232Th) and fallout radionuclide (137Cs), were measured to establish baseline data for future assessment of soil degradation in olive orchards. Similar to a previous study conducted in Slovenia (Mabit et al., 2010), a background assessment has been carried out for radioisotopes in an undisturbed reference site situated in the vicinity of an olive orchard in the municipality of Montefrio, south-west Spain. This mountainous region covers 220 km2 with an elevation ranging from 800 to 1600 meters above sea level and olive plantation, which represents 81% of the cultivated area. To establish the reference radioisotopic values - where no significant net erosion or deposition had occurred - the undisturbed and flat archaeological site of Las Pena de los Gitanos located a few hundred meters away from the agricultural fields was selected for investigation. The two main objectives of this study were: (i) to establish the soil radiometric background (NOR and 137Cs) and physicochemical information in the undisturbed area for future assessment of soil degradation and soil quality in neighbouring cultivated orchards fields, and (ii) to establish a precise reference inventory value of 137Cs fallout to prepare for an investigation to apply this radiotracer method under the Spanish orchard agro-environment to assess the magnitude and extent of soil erosion under this specific type of land use.

  19. Environmental Factors Affecting Chromium-Manganese Oxidation-Reduction Reactions in Soil

    Institute of Scientific and Technical Information of China (English)

    D.O.P.TREBIEN; L.BORTOLON; M.J.TEDESCO; C.A.BISSANI; F.A.O.CAMARGO

    2011-01-01

    Disposal of chromium (Cr) hexavalent form, Cr(Ⅵ), in soils as additions in organic fertilizers, liming materials or plant nutrient sources can be dangerous since Cr(Ⅵ) can be highly toxic to plants, animals, and humans. In order to explore soil conditions that lead to Cr(Ⅵ) generation, this study were performed using a Paleudult (Dystic Nitosol) from a region that has a high concentration of tannery operations in the Rio Grande do Sul State, southern Brazil. Three laboratory incubation experiments were carried out to examine the influences of soil moisture content and concentration of cobalt and organic matter additions on soil Cr(Ⅵ) formation and release and manganese (Mn) oxide reduction with a salt of chromium chloride (CrCl3) and tannery sludge as inorganic and organic sources of Cr(Ⅲ), respectively. The amount of Cr(Ⅲ) oxidation depended on the concentration of easily reducible Mn oxides and the oxidation was more intense at the soil water contents in which Mn(Ⅲ/Ⅳ) oxides were more stable. Soluble organic compounds in soil decreased Cr(Ⅵ) formation due to Cr(Ⅲ) complexation. This mechanism also resulted in the decrease in the oxidation of Cr(Ⅲ) due to the tannery sludge additions. Chromium(Ⅲ) oxidation to Cr(Ⅵ) at the solid/solution interface involved the following mechanisms:the formation of a precursor complex on manganese (Mn) oxide surfaces, followed by electron transfer from Cr(Ⅲ) to Mn(Ⅲ or Ⅳ),the formation of a successor complex with Mn(Ⅱ) and Cr(Ⅵ), and the breakdown of the successor complex and release of Mn(Ⅱ) and Cr(Ⅵ) into the soil solution.

  20. Short-term mesofauna responses to soil additions of corn stover biochar and the role of microbial biomass

    OpenAIRE

    Domene, X. (Xavier); Hanley, Kelly; Enders, Akio; Lehmann, Johannes

    2015-01-01

    Biochar additions have been suggested to influence soil microbial communities that, through a cascade effect, may also impact soil fauna. In turn, any direct biochar effects on fauna can influence microbial communities through grazing, physical fragmentation of organic debris (and biochar) and modifying soil structure. If biochar creates a favorable environment for soil microorganisms, it is also plausible for fauna to be attracted to such microbially enriched habitats. However, how soil faun...

  1. Wheat productivity in sandy soil as affected by plant residues, irrigation and nitrogen rates using nuclear techniques

    International Nuclear Information System (INIS)

    Increasing population in Egypt is becoming a major problem for agricultural production. The Egyptian Government must manage to increase the land productivity quickly and at low coasts. The best way to increase land productivity is the addition of organic matter to the sandy soils, to reduce the losses of water and fertilizers. The use of organic matter is considered as a good tool for maximizing soil fertility. Most of the farmers are interested with the effective use of crop residues and other recycled organic materials. The role of plant residues in modern agricultural systems has become a topic of major interest for the scientific research and agricultural authorities through improving water use efficiency. It could be concluded that the main and most effective factor affecting soil fertility, especially in sandy soils, is the organic matter content. So the main objective of the present work is to study the impact of the application of crop residues, as a source of organic matter, to sandy soils, with different nitrogen and water levels, for maximizing the input use efficiency and as well the output of wheat yield. Two field experiments were conducted at the Experimental Farm of Inshas, Nuclear Research Center, Atomic Energy Authority through 1997/1998 and 1998/1999 growing seasons. Wheat (Triticum aestivum L.) c.v. Sakha-69 was cultivated on a sandy soil to investigate: 1- the effect of different plant residues, i.e., corn ash and casourina leaves applied to sandy soils, at the rate of 10 t Fed-1, in a circle lines, 30 cm depth and 60 cm apart around the irrigation system (sprinkler); 2- two different irrigation levels namely, irrigation after 50 and 70% loss of the soil water holding capacity (SWHC) and with irrigation based on moisture depletion as measured by the Neutron Moisture Gauge; 3- two nitrogen rates as ammonium sulphate, i.e., 60 and 120 kg N /Fed, as well as the control. Nitrogen was applied in five equal splitting doses, starting 15 days after

  2. Soil nutrients affect spatial patterns of aboveground biomass and emergent tree density in southwestern Borneo.

    Science.gov (United States)

    Paoli, Gary D; Curran, Lisa M; Slik, J W F

    2008-03-01

    Studies on the relationship between soil fertility and aboveground biomass in lowland tropical forests have yielded conflicting results, reporting positive, negative and no effect of soil nutrients on aboveground biomass. Here, we quantify the impact of soil variation on the stand structure of mature Bornean forest throughout a lowland watershed (8-196 m a.s.l.) with uniform climate and heterogeneous soils. Categorical and bivariate methods were used to quantify the effects of (1) parent material differing in nutrient content (alluvium > sedimentary > granite) and (2) 27 soil parameters on tree density, size distribution, basal area and aboveground biomass. Trees > or =10 cm (diameter at breast height, dbh) were enumerated in 30 (0.16 ha) plots (sample area = 4.8 ha). Six soil samples (0-20 cm) per plot were analyzed for physiochemical properties. Aboveground biomass was estimated using allometric equations. Across all plots, stem density averaged 521 +/- 13 stems ha(-1), basal area 39.6 +/- 1.4 m(2) ha(-1) and aboveground biomass 518 +/- 28 Mg ha(-1) (mean +/- SE). Adjusted forest-wide aboveground biomass to account for apparent overestimation of large tree density (based on 69 0.3-ha transects; sample area = 20.7 ha) was 430 +/- 25 Mg ha(-1). Stand structure did not vary significantly among substrates, but it did show a clear trend toward larger stature on nutrient-rich alluvium, with a higher density and larger maximum size of emergent trees. Across all plots, surface soil phosphorus (P), potassium, magnesium and percentage sand content were significantly related to stem density and/or aboveground biomass (R (Pearson) = 0.368-0.416). In multiple linear regression, extractable P and percentage sand combined explained 31% of the aboveground biomass variance. Regression analyses on size classes showed that the abundance of emergent trees >120 cm dbh was positively related to soil P and exchangeable bases, whereas trees 60-90 cm dbh were negatively related to these

  3. Rational Utilization of Salt Affected Soils and Saline Waters for Crop Production and the Protection of Soil and Water in Agricultural Catchments

    International Nuclear Information System (INIS)

    Sustainable management of land and water resources in arid and semi-arid regions is of concern as a result of increased population pressure and the need for more food and fibre. Soil and water salinity is widespread across the arid and semiarid regions of Australia, the Arabian Peninsula, Central Asia, North Africa, North America and South Asia, where it is a major constraint for agricultural productivity and the livelihoods of the rural population. Globally, salinity spreads across at least 75 countries and about 20% of irrigated land is affected by salinity. Recent estimates suggest that up to 50% of irrigated land has become saline in some of these regions. While both natural processes (primary) and anthropogenic activities (secondary) cause soil and water salinity, the latter contributes more to loss of agricultural productivity in these regions. In addition to anthropogenic activities global climate change also accelerates soil and water salinity through the following processes: - Unpredictable evaporation and transpiration: Climate change alters the evapotranspiration and water balance at the land surface, and changes the groundwater recharge. In shallow aquifers, the groundwater responds to these changes quickly and moves towards the surface bringing salt with it and accelerating soil salinization (Yu et al., 2002). - Reduction in rainfall: Current best estimates suggest that in arid and semi-arid catchments, a reduction in rainfall due to climate change will result in up to double the reduction in run-off from catchments and river flow. Under such conditions, river salinity will increase as a result of reduced river dilution (CSIRO, 2008). - Influence of tidal waves: In coastal areas, the risk of soil and water salinization under climate change is even higher because the increased sea level and frequency of tidal waves brings salt water into inland freshwaters and is lost then to groundwater, making it saline. In low-lying areas, salty river water moves to

  4. Ozone exposure of field-grown winter wheat affects soil mesofauna in the rhizosphere

    Energy Technology Data Exchange (ETDEWEB)

    Schrader, Stefan, E-mail: stefan.schrader@vti.bund.d [Johann Heinrich von Thuenen-Institute (vTI), Federal Research Institute for Rural Areas, Forestry and Fisheries, Institute of Biodiversity, Bundesallee 50, 38116 Braunschweig (Germany); Bender, Juergen; Weigel, Hans-Joachim [Johann Heinrich von Thuenen-Institute (vTI), Federal Research Institute for Rural Areas, Forestry and Fisheries, Institute of Biodiversity, Bundesallee 50, 38116 Braunschweig (Germany)

    2009-12-15

    A 2-year open-top chamber experiment with field-grown winter wheat (Triticum aestivum L. cv. Astron) was conducted to examine the effects of ozone on plant growth and selected groups of soil mesofauna in the rhizosphere. From May through June in each year, plants were exposed to two levels of O{sub 3}: non-filtered (NF) ambient air or NF+ 40 ppb O{sub 3} (NF+). During O{sub 3} exposure, soil sampling was performed at two dates according to different plant growth stages. O{sub 3} exposure reduced above- and below-ground plant biomass in the first year, but had little effect in the second year. The individual density of enchytraeids, collembolans and soil mites decreased significantly in the rhizosphere of plants exposed to NF+ in both years. Differences were highest around anthesis, i.e. when plants are physiologically most active. The results suggest that elevated O{sub 3} concentrations may influence the dynamic of decomposition processes and the turnover of nutrients. - Ozone reduced the individual densities of enchytraeids, collembolans and soil mites in the rhizosphere of winter wheat indirectly via the plant-soil-system.

  5. How physical alteration of technic materials affects mobility and phytoavailabilty of metals in urban soils?

    Science.gov (United States)

    El Khalil, Hicham; Schwartz, Christophe; El Hamiani, Ouafae; Sirguey, Catherine; Kubiniok, Jochen; Boularbah, Ali

    2016-06-01

    One fundamental characteristic distinguishing urban soils from natural soils is the presence of technic materials or artefacts underlining the influence of human activity. These technic materials have different nature (organic or inorganic) and origins. They contribute to the enrichment of the soil solution by metallic trace elements. The present study aims to determine the effect of physical alteration of the technic coarse fraction on the bioavailability of metallic trace elements in urban Technosols. In general, results show that physical alteration increases the metallic trace elements water extractible concentrations of technic materials. The ability of lettuce to accumulate metallic trace elements, even at low concentrations, underlines the capacity of technic materials to contaminate the anthropised soil solution by bioavailable metals. The highest metal levels, accumulated by the various organs of the lettuce (leaves and roots), were measured in plants grown in presence of metallic particles mixtures. This indicates that the majority of metallic trace elements released by this technic constituent is bioavailable and explains the low plant biomass obtained. The abundant part of metallic trace elements released by the other technic constituents (building materials, bones, wood, plastic and fabric-paper) remains less bioavailable. Under anthropised soil conditions, technic materials have a significant effect on the metallic trace elements behavior. They impact the flow of these metallic elements in Technosols, which can increase their bioavailability and, therefore, the contamination of the food chain. PMID:26999750

  6. Mycorrhizal effectiveness and manganese toxicity in soybean as affected by soil type and endophyte

    Directory of Open Access Journals (Sweden)

    Nogueira Marco Antonio

    2003-01-01

    Full Text Available Mycorrhizal plants may present Mn toxicity alleviation and this depends on the plant-endophyte-environment interaction. The effectiveness of three arbuscular mycorrhizal fungi (AMF (Glomus macrocarpum, G. etunicatum, G. intraradices and a control without AMF in two soils: Typic Rhodudalf with high Mn availability and a Typic Quartzipsamment, with low Mn availability, was evaluated in a time-course experiment at 3, 6, 9 and 12 weeks after soybean (Glycine max L. seedling emergence. The objective was to select the most effective AMF species to enhance plant growth and to assess its effects upon Mn uptake by plants and Mn availability in the soil. For the sandy soil, AMF inoculation resulted in increased plant biomass, especially with G. intraradices and G. etunicatum. Lower Mn concentrations were observed in shoot and root of mycorrhizal plants. For the clayey soil, there was also an increase in plant biomass, but only for plants inoculated with G. intraradices and G. etunicatum. Mycorrhizal plants presented higher Mn concentrations in shoot and root and there was an increase of available Mn in the soil, in relation to the control, especially in the treatment with G. macrocarpum. When inoculated with G. macrocarpum, plants presented Mn toxicity symptoms and reduced biomass in comparison to control plants. The effects of mycorrhizal inoculation, either positive or negative, were most intense at 9 and 12 weeks.

  7. Ozone exposure of field-grown winter wheat affects soil mesofauna in the rhizosphere

    International Nuclear Information System (INIS)

    A 2-year open-top chamber experiment with field-grown winter wheat (Triticum aestivum L. cv. Astron) was conducted to examine the effects of ozone on plant growth and selected groups of soil mesofauna in the rhizosphere. From May through June in each year, plants were exposed to two levels of O3: non-filtered (NF) ambient air or NF+ 40 ppb O3 (NF+). During O3 exposure, soil sampling was performed at two dates according to different plant growth stages. O3 exposure reduced above- and below-ground plant biomass in the first year, but had little effect in the second year. The individual density of enchytraeids, collembolans and soil mites decreased significantly in the rhizosphere of plants exposed to NF+ in both years. Differences were highest around anthesis, i.e. when plants are physiologically most active. The results suggest that elevated O3 concentrations may influence the dynamic of decomposition processes and the turnover of nutrients. - Ozone reduced the individual densities of enchytraeids, collembolans and soil mites in the rhizosphere of winter wheat indirectly via the plant-soil-system.

  8. Applications of Fertilizer Cations Affect Cadmium and Zinc Concentrations in Soil Solutions and Uptake by Plants

    DEFF Research Database (Denmark)

    Lorenz, S. E.; Hamon, R. E.; McGrath, S. P.;

    1994-01-01

    A pot experiment was conducted to study changes over time of Cd and Zn in soil solution and in plants. Radish was grown in a soil which had been contaminated with heavy metals prior to 1961. Constant amounts of a fertilizer solution (NH4N03, KN03) were added daily. Soil solution was obtained at...... intervals by displacement with water. The cumulative additions of small amounts of fertilizers were made equal to the plants' requirements at the final harvest but were found to exceed them during most of the experiment. Excess fertilizers caused substantial increases of major (K, Ca, Mg) and heavy......-metal (Cd, Zn) ions in soil solutions and a decrease in soil pH, probably due to ion-exchange mechanisms and the dissolution of carbonates. Uptake of Cd and Zn into leaves was correlated with the mass flow of Cd (adjusted r2 = 0.798) and Zn (adjusted r2=0.859). Uptake of K, Ca and Mg by the plants was...

  9. Soil and Waste Matrix Affects Spatial Heterogeneity of Bacteria Filtration during Unsaturated Flow

    Directory of Open Access Journals (Sweden)

    Adrian Unc

    2015-02-01

    Full Text Available Discontinuous flows resulting from discrete natural rain events induce temporal and spatial variability in the transport of bacteria from organic waste through soils in which the degree of saturation varies. Transport and continuity of associated pathways are dependent on structure and stability of the soil under conditions of variable moisture and ionic strength of the soil solution. Lysimeters containing undisturbed monoliths of clay, clay loam or sandy loam soils were used to investigate transport and pathway continuity for bacteria and hydrophobic fluorescent microspheres. Biosolids, to which the microspheres were added, were surface applied and followed by serial irrigation events. Microspheres, Escherichia coli, Enterococcus spp., Salmonella spp. and Clostridium perfringens were enumerated in drainage collected from 64 distinct collection areas through funnels installed in a grid pattern at the lower boundary of the monoliths. Bacteria-dependent filtration coefficients along pathways of increasing water flux were independent of flow volume, suggesting: (1 tracer or colloid dependent retention; and (2 transport depended on the total volume of contiguous pores accessible for bacteria transport. Management decisions, in this case resulting from the form of organic waste, induced changes in tortuosity and continuity of pores and modified the effective capacity of soil to retain bacteria. Surface application of liquid municipal biosolids had a negative impact on transport pathway continuity, relative to the solid municipal biosolids, enhancing retention under less favourable electrostatic conditions consistent with an initial increase in straining within inactive pores and subsequent by limited re-suspension from reactivated pores.

  10. Volatiles produced by soil-borne endophytic bacteria increase plant pathogen resistance and affect tritrophic interactions.

    Science.gov (United States)

    D'Alessandro, Marco; Erb, Matthias; Ton, Jurriaan; Brandenburg, Anna; Karlen, Danielle; Zopfi, Jakob; Turlings, Ted C J

    2014-04-01

    Volatile organic compounds (VOCs) released by soil microorganisms influence plant growth and pathogen resistance. Yet, very little is known about their influence on herbivores and higher trophic levels. We studied the origin and role of a major bacterial VOC, 2,3-butanediol (2,3-BD), on plant growth, pathogen and herbivore resistance, and the attraction of natural enemies in maize. One of the major contributors to 2,3-BD in the headspace of soil-grown maize seedlings was identified as Enterobacter aerogenes, an endophytic bacterium that colonizes the plants. The production of 2,3-BD by E. aerogenes rendered maize plants more resistant against the Northern corn leaf blight fungus Setosphaeria turcica. On the contrary, E. aerogenes-inoculated plants were less resistant against the caterpillar Spodoptera littoralis. The effect of 2,3-BD on the attraction of the parasitoid Cotesia marginiventris was more variable: 2,3-BD application to the headspace of the plants had no effect on the parasitoids, but application to the soil increased parasitoid attraction. Furthermore, inoculation of seeds with E. aerogenes decreased plant attractiveness, whereas inoculation of soil with a total extract of soil microbes increased parasitoid attraction, suggesting that the effect of 2,3-BD on the parasitoid is indirect and depends on the composition of the microbial community. PMID:24127750

  11. Dissolution of Aluminum in Variably Charged Soils as Affected by Low-Molecular-Weight Organic Acids

    Institute of Scientific and Technical Information of China (English)

    LI Jiu-Yu; XU Ren-Kou; JI Guo-Liang

    2005-01-01

    Low-molecular-weight (LMW) organic acids exist widely in soils and play an important role in soil processes such as mineral weathering, nutrient mobilization and Al detoxification. In this research, a batch experiment was conducted to examine the effects of LMW organic acids on dissolution of aluminum in two variably charged soils, an Ultisol and an Oxisol. The results showed that the LMW organic acids enhanced the dissolution of Al in the two investigated soils in the following order: citric > oxalic > malonic > malic > tartaric > salicylic > lactic > maleic. This was generally in agreement with the magnitude of the stability constants for the Al-organic complexes. The effects of LMW organic acids on Al dissolution were greater in the Ultisol than in the Oxisol as compared to their controls. Also, the accelerating effects of citric and oxalic acids on dissolution of Al increased with an increase in pH, while the effects of lactic and salicylic acids decreased. Additionally, when the organic acid concentration was less than 0.2 mmol L-1, the dissolution of Al changed little with increase in acid concentration. However, when the organic acid concentration was greater than 0.2 mmol L-1,the dissolution of Al increased with increase in acid concentration. In addition to the acid first dissociation constant and stability constant of Al-organic complexes, the promoting effects of LMW organic acids on dissolution of Al were also related to their sorption-desorption equilibrium in the soils.

  12. Soil organic matter composition along a slope in an erosion-affected arable landscape in North East Germany

    Science.gov (United States)

    Ellerbrock, Ruth, H.; Gerke, Horst, H.; Deumlich, Detlef

    2016-04-01

    In hummocky landscapes, soil erosion is forming truncated profiles at steep slope positions and colluvial soils in topographic depressions thereby affecting soil organic carbon (SOC) storage. However, the knowledge on the spatial distribution and composition of differently stable organic matter (OM) fractions in arable landscapes is still limited. Here, amount and composition of OM from top- and subsoil horizons at eroded, colluvic, and non -eroded slope positions were compared. The horizons were from a Luvisol at plateau (LV), an eroded Luvisol (eLV) at mid slope (6%slope gradient), a calcaric Regosol (caRG) at steep slope (13%), and a colluvic Regosol (coRG) at hollow position. Water soluble (OM-W) and pyrophosphate soluble (OM-PY) fractions were extracted sequentially. Soil samples, OM fractions, and extraction residues were analyzed with transmission Fourier transform infrared (FTIR) spectroscopy. The soluble fractions were 3% of SOC for OM-W and 15% of SOC for OM-PY. For topsoil samples, extract ion rates were independent of slope position. The highest intensities of both, C-H (alkyl groups) and C=O (carboxyl groups) absorption band, were found in FTIR spectra of OM-PY from top and subsoil horizons at the steep slope position (caRG). The C-H/C=O ratio in OM-PY decreased with increasing contents of oxalate soluble Fe and Al oxides from steep slope (0.25 for caRG-Ap) towards plateau, and hollow position (0.09 for coRG-Ap) except for the Bt -horizons. This relation is reflecting that the down slope-deposited Ap material, which is higher in poorly crystalline Fe an d Al oxides, consists of relatively stable OM. This OM is enriched in C=O groups that are known for their interaction with soil minerals. These OM-mineral interactions may help explaining C storage in arable soil landscapes.

  13. Soil Chemical Properties and Nutrient Uptake of Cocoa as Affected by Application of Different Organic Matters and Phosphate Fertilizers

    Directory of Open Access Journals (Sweden)

    Sugiyanto Sugiyanto

    2008-07-01

    Full Text Available Effort repair of land quality better be done by simultan namely with application of organic matters and inorganic fertilization. The objective of this research is to study the effect of varied organic matters source and phosphate fertilizers on the chemicals soil characteristic and cocoa nutrient uptake. The experiment was laid experimentally in split-plot design and environmentally in randomized complete block design. The main plot was source of P consisted of, control, SP 36 and rock phosphate in dosage of 200 mg P2O5 per kg of air dry soil. Source of organic matter as sub-plot consisted of control (no organic matter, cow dung, cocoa pod husk compost and sugar cane filter cake, each in dosage of 2.5 and 5.0%. Result of this experiment showed application of cow dung, cocoa pod husk compost and sugar cane filter cake increased content of C, N, Ca exchangeable, Fe available, and pH in soil, and SP 36 increased availability of P in soil. Application of sugar cane filter cake increased N, K, Ca, Mg, and SO4 uptake but did not increase Cl uptake, application of cow dung in dosage 5% increased N, K, and Cl uptake and cocoa pod husk compost dosage 5% increased N and K uptake of cocoa. SP 36 increased Mg uptake of cocoa but rock phosphate did not increase it. They were not interaction between organic matters and phosphate fertilizers to nutrient uptake of cocoa. Nutrient soil content as affected by organic matters correlated with nutrient uptake of cocoa.Key words : soil chemical properties, nutrient uptake, cocoa, organic matter, phosphate fertlizers.

  14. Exchangeable basic cations and nitrogen distribution in soil as affected by crop residues and nitrogen

    Directory of Open Access Journals (Sweden)

    Ciro Antonio Rosolem

    2011-06-01

    Full Text Available In this work, a greenhouse experiment was conducted to study the effects of N fertilization and residues of pearl millet, black oats and oilseed radish on pH and Ca, Mg, K, NO3-, and NH4+ distribution within the profile of a Distroferric Red Latosol. The equivalent of 8 t ha-1 of plant residues were placed on soil surface. Lime was applied on the soil surface and nitrogen was applied over the straw at 0, 50, 100, and 150 mg kg-1, as ammonium nitrate. Corn was grown for 57 days. Calcium contents and pH in the soil profile were decreased by Pearl millet residue, while black oat and oilseed radish increased Ca contents and these effects are not related with Ca contents in residue tissue. However, the presence of plant residues increased nitrate, ammonium, and potassium contents in the deeper layers of the pots.

  15. Yield-loss Models for Tobacco Infected with Meloidogyne incognita as Affected by Soil Moisture.

    Science.gov (United States)

    Wheeler, T A; Barker, K R; Schneider, S M

    1991-10-01

    Yield-loss models were developed for tobacco infected with Meloidogyne incognita grown in microplots under various irrigation regimes. The rate of relative yield loss per initial nematode density (Pi), where relative yield is a proportion of the value of the harvested leaves in uninfected plants with the same irrigation treatment, was greater under conditions of water stress or with high irrigation than at an intermediate level of soil moisture. The maximum rate of plant growth per degree-day (base 10 C) was reduced as nematode Pi increased when plots contained adequate water. When plants were under water stress, increasing Pi did not luther reduce the maximum rate of plant growth (water stress was the limiting factor). Cumulative soil matric potential values were calculated to describe the relationship between available water in the soil (matric potential) due to the irrigation treatments and subsequent plant growth. PMID:19283140

  16. Distributed Modeling of soil erosion and deposition affected by buffer strips

    DEFF Research Database (Denmark)

    Khademalrasoul, Ataalah; Heckrath, Goswin Johann; Iversen, Bo Vangsø;

    bodies. Buffer zones can be efficient in terms of retaining sediment and phosphorus transported by water erosion. This study aimed at parameterizing a spatial distributed erosion model to evaluate the effect of different buffer zone properties and dimension. It was our hypothesis that the placement and......Soil degradation and environmental impacts due to water erosion are a growing concern globally. Large parts of Denmark are covered by gently rolling moraine landscape with moderately to locally highly erodible soils where water erosion causes off-site problems in the form of eutrophication of water...... was surveyed during the runoff season. In addition, organic carbon and phosphorous contents as well as bulk density were determined in soils of eroding and depositional sites. General buffer zone properties were recorded. Here we present results from scenario analyses comparing measured sediment...

  17. 喀斯特石漠化地区土壤动物功能类群及培育研究%Research on the function groups of soil fauna in Karst stone desertification area

    Institute of Scientific and Technical Information of China (English)

    王仙攀; 陈浒; 熊康宁; 李晋; 赵基; 徐玲; 罗井升

    2012-01-01

    为了解石漠化地区土壤动物功能类群对生态恢复的响应,2010年9月至11月在贵州花江喀斯特峡谷区对不同石漠化等级的土壤动物进行了田间培育研究。结果显示:喀斯特石漠化区土壤动物可以划分为杂食性、植食性、腐食性和捕食性4个生态功能类群,各样地均以杂食性动物的物种数量和个体数量所占比例最大,捕食性动物所占比例较小;土壤动物功能类群随石漠化程度加深,物种数减少,个体数量不存在这种关系;物种丰富度、Shannon多样性指数随着石漠化程度加深而升高,均匀性、优势度指数则趋于下降;土壤动物培育发现,不同等级石漠化对土壤动物功能类群分布有影响,土壤动物种类和数量分布可以揭示石漠化生态恢复现状。%In order to understand functional class groups of soil animals in rocky desertification area response to ecological rehabilitation,we took artificial propagation in fields according to different rocky desertification degree in Huajiang gorge area,Guizhou province,during September to November,2010.The results showed soil animals in rocky desertification land could be divided into carnivorous,herbivorous,saprophagous and predatory 4 ecological functional groups.In all observation fields,omnivorous animals constituted the largest class in individual number and species number,predatory animals was the smallest;With the rocky desertification degree aggravating,soil animal species reduced.Richness,Shannon index increased with the rocky desertification degrees;Evenness and dominance index decreased.Fields propagation studies indicated that different rocky desertification degrees influenced upon functional groups distribution of soil animals,and the distribution of soil animal species and the number suggest the rehabilitation status of rocky desertification.

  18. Overland flow generation mechanisms affected by topsoil treatment: Application to soil conservation

    Science.gov (United States)

    González Paloma, Hueso; Juan Francisco, Martinez-Murillo; Damian, Ruiz-Sinoga Jose; Hanoch, Lavee

    2015-04-01

    Hortonian overland-flow is responsible for significant amounts of soil loss in Mediterranean geomorphological systems. Restoring the native vegetation is the most effective way to control runoff and sediment yield. During the seeding and plant establishment, vegetation cover may be better sustained if soil is amended with an external source. Four amendments were applied in an experimental set of plots: straw mulching (SM); mulch with chipped branches of Aleppo Pine (Pinus halepensis L.) (PM); TerraCotten hydroabsobent polymers (HP); sewage sludge (RU); and control (C). Plots were afforested following the same spatial pattern, and amendments were mixed with the soil at the rate 10 Mg ha-1. This research demonstrates the role played by the treatments in overland flow generation mechanism (runoff, overland flow and soil moisture along the soil profile). The general overland flow characteristics showed that in the C plots the average overland flow was 8.0 ± 22.0 l per event, and the HP plots produced a similar mean value (8.1 ± 20.1 l). The average overland flow per event was significantly less for soil amended with SM, PM or RU (2.7 ± 8.3 l; 1.3 ± 3.5 l and 2.2 ± 5.9 l, respectively). There was a similar trend with respect to the maximum overland flow. The mean sediment yield per event was relatively high in the C and HP plots (8.6 ± 27.8 kg and 14.8 ± 43.4 kg, respectively), while significantly lower values were registered in the SM, PM and RU plots (0.4 ± 1.0 kg; 0.2 ± 0.3 kg and 0.2 ± 0.3 kg, respectively). Very similar trends were found for the maximum sediment yield. Regarding to the soil moisture values, there was a difference in the trends between the C and HP plots and the SM, PM and RU plots. In the C and HP plots the general trend was for a decrease in soil moisture downward through the soil profile, while in the SM, PM and RU plots the soil moisture remained relatively constant or increased, except for the RU treatment in which the soil moisture

  19. Movement of carbon to roots of food legumes as affected by soil moisture and fertilizer potassium

    International Nuclear Information System (INIS)

    Food legumes are an important component of agricultural systems in developing countries. They are cultivated in a wide range of environments where soil moisture could be generally considered limiting for optimum growth and yield. In terms of vegetative growth, root systems of plants adapt to extract the limited moisture from dry soils. Although it is known that fertilizer K helps plants mitigate soil moisture stress, this has not been evaluated on a comparative basis in food legumes. Therefore, a study was carried out under controlled conditions to determine the role of K+ in the movement of labelled C in three tropical food legumes that have differing optimal soil-moisture requirements. Common bean (Phaseolus vulgaris), mung bean (Vigna radiata), and cowpea (Vigna unguiculata) were grown under two moisture regimes with three levels of K+ (01, 1.0 and 3.0 mM K). Uniform seedlings of the three species were transplanted into pots containing quartz sand, maintained at two soil-moisture levels (High, less than 25% depleted of available soil moisture; Low, more than 50% depleted), by weighing at 3-day intervals and adding the required water or nutrient solution. The modified nutrient solutions had 0.1, 1.0 or 3.0 mM K+ with 1.5 mM N. The plants were kept in a growth chamber, maintained at 25 deg. /18 deg. C day/night, with a 16-h photoperiod, and at 60% humidity. At the V4 growth stage of each species, four plants were selected randomly, and approximately 1 cm2 of the upper surface of the youngest fully expanded leaf abraded with Carborundum. Thereafter, 5 μL of 14C contained in a 5-mM solution of sucrose (148 KBq) was applied to the abraded area. Another 10 μL of unlabelled sucrose was applied to the same area 10 min later and the plants replaced. After 24 h, they were carefully removed, roots washed, dried and weighed. Thereafter, the samples were ground and digested, and labelled C determined by liquid scintillation. Cowpea, the species most adapted to soil

  20. 城市化对土壤环境的影响%The Affects of Urbanization to Soil Environment

    Institute of Scientific and Technical Information of China (English)

    廖金凤

    2001-01-01

    Urbanization affects the soil environment deeply.Municipal polluted water,industrial waste gas,waste gas of automobiles and garbage can change the physical and chemical nature of the soil.Some actions must be taleen to prevent the soil pollution and improve municipal soil environment such as reasonable industry allocation,rectifying the resource of pollution,enhancement of the custody on agriculture environment,etc.%城市化对土壤环境产生深刻影响,城市污水灌溉、工业废气和汽车废气、城市生活垃圾等都会改变土壤的理化性质。防治土壤污染、改善城市土壤环境,必须工业合理布局,治理工业污染源,加强农业环境的监测等。

  1. Combined Chemical and Mineralogical Evidence for Heavy Metal Binding in Mining- and Smelting-Affected Alluvial Soils

    Institute of Scientific and Technical Information of China (English)

    A. VAN(E)K; V. ETTLER; T. GRYGAR; L. BOR(U)VKA; O. (S)EBEK; O. DR(A)BEK

    2008-01-01

    The binding of metallic contaminants (Pb, Cd, and Zn) and As on soil constituents was studied on four highly con-taminated alluvial soil profiles from the mining/smelting district of Pribram (Czech Republic) using a combination of mineralogical and chemical methods. Sequential extraction analysis (SEA) was supplemented by mineralogical investi-gation of both bulk samples and hcavy mineral fractions using X-ray diffraction analysis (XRD) and scanning electron microscopy with an energy dispersive X-ray spectrometer (SEM/EDS). The mineralogy of Fe and Mn oxides was studied by voltammetry of microparticles (VMP) and diffuse reflectance spectrometry (DRS). Zinc and Pb were predominantly were detected in soils by XRD and SEM/EDS. In contrast, Cd was the most mobile contaminant and was predominantly present in the exchangeable fraction. Arsenic was bound to the residual and reducible fractions (corresponding to Fe oxides or to unidentified Fe-Pb arsenates). SEM/EDS observations indicate the predominant affinity of Pb for Mn oxides,and to a lesser extent, for Fe oxidcs. Thus, a more suitable SEA procedure should be used for these mining-affected soils to distinguish between the contaminant fraction bound to Mn oxides and Fe oxides.

  2. Vertical Distribution of Cadmium and Lead on Soils Affected by Metropolitan Refuse Disposal in Owerri, Southeastern Nigeria

    Directory of Open Access Journals (Sweden)

    E.U. Onweremadu

    2011-01-01

    Full Text Available The authors investigated distribution of cadmium (Cd and lead (Pb in soil profile pits affected by municipal solid wastes in Avu dumpsite in Owerri, Southeastern Nigeria in 2010. Transect soil survey technique was used in aligning profile pits for field studies and sampling. Standard procedures were used in digging, describing and sampling from profile pits. Sieved soil samples were subjected to laboratory analyses and data were analyzed statistically using coefficient of variation measured in percentages. Results showed higher values of % CV in silt and clay contents. Variability of clay increased from dumpsite (CV=43.77 % to moderately dumped site (CV=62.73% decreased in slightly dumped side (20.98%. Highest mean values of organic matter (26.8 g/kg and pH water (5.7 were reported in heavily dumped site. Organic Matter showed very significant positive relationship with Cd (r = 0.92; p = 0.01 and Pb (r=0.97; P = 0.97. There is need to include more soil attributes; results of which should be subjected to multi-variate techniques for more reliability and confidence especially in field applications.

  3. Psychomotor approach in children affected by nonretentive fecal soiling (FNRFS: a new rehabilitative purpose

    Directory of Open Access Journals (Sweden)

    Esposito M

    2013-09-01

    Full Text Available Maria Esposito,1 Francesca Gimigliano,1,2 Maria Ruberto,2 Rosa Marotta,3 Beatrice Gallai,4 Lucia Parisi,5 Serena Marianna Lavano,3 Giovanni Mazzotta,6 Michele Roccella,5 Marco Carotenuto1 1Center for Childhood Headache, Clinic of Child and Adolescent Neuropsychiatry, Department of Mental Health, Physical and Preventive Medicine, Second University of Naples, Naples, Italy; 2Department of Odontostomathologic Disciplines, Head Pathology, Orthopedic Sciences, Second University of Naples, Italy; 3Department of Psychiatry, Magna Graecia University of Catanzaro, Catanzaro, Italy; 4Unit of Child and Adolescent Neuropsychiatry, University of Perugia, Perugia, Italy; 5Child Neuropsychiatry, Department of Psychology, University of Palermo, Palermo, Italy; 6Unit of Child and Adolescent Neuropsychiatry, AUSL Umbria, Terni, Italy Background: According to the Rome III criteria, encopresis without constipation was defined as nonretentive fecal soiling (FNRFS with not yet well understood etiology. Treatment approaches reported in the literature with varying results include biofeedback, hypnosis, reflexology, and Internet-based educational programs. In developmental age, another behavioral treatment could be identified in the psychomotor approach, which is called psychomotricity in the European countries, or is also known as play therapy. The aim of the present study was to verify the safety and efficacy of play therapy plus toilet training in a small sample of prepubertal children affected by FNRFS. Materials and methods: Twenty-six patients (group 1; 16 males, mean age of 5.92 ± 0.84 years underwent a psychomotor approach therapy program in association with toilet training for 6 months, and the other 26 subjects (group 2; 17 males, mean age of 5.76 ± 0.69 underwent the sole toilet training program for 6 months. During the observational time period (T0 and after 6 months (T1 of both treatments, the patients were evaluated for FNRFS frequency and for the

  4. Current Status of Trace Metal Pollution in Soils Affected by Industrial Activities

    Directory of Open Access Journals (Sweden)

    Ehsanul Kabir

    2012-01-01

    Full Text Available There is a growing public concern over the potential accumulation of heavy metals in soil, owing to rapid industrial development. In an effort to describe the status of the pollutions of soil by industrial activities, relevant data sets reported by many studies were surveyed and reviewed. The results of our analysis indicate that soils were polluted most significantly by metals such as lead, zinc, copper, and cadmium. If the dominant species are evaluated by the highest mean concentration observed for different industry types, the results were grouped into Pb, Zn, Ni, Cu, Fe, and As in smelting and metal production industries, Mn and Cd in the textile industry, and Cr in the leather industry. In most cases, metal levels in the studied areas were found to exceed the common regulation guideline levels enforced by many countries. The geoaccumulation index (Igeo, calculated to estimate the enrichment of metal concentrations in soil, showed that the level of metal pollution in most surveyed areas is significant, especially for Pb and Cd. It is thus important to keep systematic and continuous monitoring of heavy metals and their derivatives to manage and suppress such pollution.

  5. Bioavailability of zinc and phosphorus in calcareous soils as affected by citrate exudation

    NARCIS (Netherlands)

    Duffner, A.; Hoffland, E.; Temminghoff, E.J.M.

    2012-01-01

    Aims Zinc (Zn) and phosphorus (P) deficiency often occurs at the same time and limits crop production in many soils. It has been suggested that citrate root exudation is a response of plants to both deficiencies. We used white lupin (Lupinus albus L.) as a model plant to clarify if citrate exuded by

  6. Cattle activities affect abundance and activity of nitrifying and denitrifying microbial communities in upland soil

    Czech Academy of Sciences Publication Activity Database

    Chroňáková, Alica; Radl, V.; Čuhel, Jiří; Gattinger, A.; Šimek, Miloslav; Elhottová, Dana; Schloter, M.

    Uppsala : Swedish University of Agriculture Sciences, 2007. [Achievements of COST 856. Denitrification and related aspects. Final meeting of the ESF COST Action 856 /14./. 05.12.2007-08.12.2007, Uppsala] Institutional research plan: CEZ:AV0Z60660521 Keywords : cattle activities * nitrifying and denitrifying microbial communities * upland soil Subject RIV: EH - Ecology, Behaviour

  7. FACTORS AFFECTING THE HYDRAULIC BARRIER PERFORMANCE OF SOIL-BENTONITE MIXTURE CUT-OFF WALL

    Science.gov (United States)

    Takai, Atsushi; Inui, Toru; Katsumi, Takeshi; Kamon, Masashi; Araki, Susumu

    Containment technique using cut-off walls is a valid method against contaminants in subsurface soil and/or groundwater. This paper states laboratory testing results on hydraulic barrier performance of Soil-Bentonite (SB), which is made by mixing bentonite with in-situ soil. Since the bentonite swelling is sensitive to chemicals, chemical compatibility is important for the hydraulic barrier performance of SB. Hydraulic conductivity tests using flexible-wall permeameter were conducted on SB specimens with various types and concentrations of chemicals in the pore water and/or in the permeant and with various bentonite powder contents. As a result, hydraulic barrier performance of SB was influenced by the chemical concentration in the pore water of original soil and bentonite powder content. In the case that SB specimens have damage parallel to the permeating direction, no significant leakage in the SB occurs by the self-sealing property of SB. In addition, the hydraulic conductivity values of SB have excellent correlation with their plastic indexes and swelling pr essures, thus these properties of SB have some possibility to be indicators for estimation of the hydraulic barrier performance of SB.

  8. Nature's amazing biopolymer: basic mechanical and hydrological properties of soil affected by plant exudates

    Science.gov (United States)

    Naveed, Muhammad; Roose, Tiina; Raffan, Annette; George, Timothy; Bengough, Glyn; Brown, Lawrie; Keyes, Sam; Daly, Keith; Hallett, Paul

    2016-04-01

    Plant exudates are known to have a very large impact on soil physical properties through changes in mechanical and hydrological processes driven by long-chain polysaccharides and surface active compounds. Whilst these impacts are well known, the basic physical properties of these exudates have only been reported in a small number of studies. We present data for exudates obtained from barley roots and chia seeds, incorporating treatments examining biological decomposition of the exudates. When these exudates were added to a sandy loam soil, contact angle and drop penetration time increased exponentially with increasing exudate concentration. These wetting properties were strongly correlated with both exudate density and zero-shear viscosity, but not with exudate surface tension. Water holding capacity and water repellency of exudate mixed soil tremendously increased with exudate concentration, however they were significantly reduced on decomposition when measured after 14 days of incubation at 16C. Mechanical stability greatly increased with increasing exudate amendment to soils, which was assessed using a rheological amplitude sweep test near saturation, at -50 cm matric potential (field capacity) using indentation test, and at air-dry condition using the Brazilian test. This reflects that exudates not only attenuate plant water stress but also impart mechanical stability to the rhizosphere. These data are highly relevant to the understanding and modelling of rhizosphere development, which is the next phase of our research.

  9. PRECEDING AFFECTS CADMIUM AND ZINC OF WHEAT GROWN IN SALINE SOILS OF CENTRAL IRAN

    Science.gov (United States)

    Enhanced Cd concentrations in wheat grain produced on saline soils of central Iran have been recently reported. Considering that wheat bread is a major dietary component for the Iranian people, finding some practical approaches to decrease Cd concentration in wheat grain were investigated. Thus, the...

  10. Metal contaminated biochar and wood ash negatively affect plant growth and soil quality after land application.

    Science.gov (United States)

    Jones, D L; Quilliam, R S

    2014-07-15

    Pyrolysis or combustion of waste wood can provide a renewable source of energy and produce byproducts which can be recycled back to land. To be sustainable requires that these byproducts pose minimal threat to the environment or human health. Frequently, reclaimed waste wood is contaminated by preservative-treated timber containing high levels of heavy metals. We investigated the effect of feedstock contamination from copper-preservative treated wood on the behaviour of pyrolysis-derived biochar and combustion-derived ash in plant-soil systems. Biochar and wood ash were applied to soil at typical agronomic rates. The presence of preservative treated timber in the feedstock increased available soil Cu; however, critical Cu guidance limits were only exceeded at high rates of feedstock contamination. Negative effects on plant growth and soil quality were only seen at high levels of biochar contamination (>50% derived from preservative-treated wood). Negative effects of wood ash contamination were apparent at lower levels of contamination (>10% derived from preservative treated wood). Complete removal of preservative treated timber from wood recycling facilities is notoriously difficult and low levels of contamination are commonplace. We conclude that low levels of contamination from Cu-treated wood should pose minimal environmental risk to biochar and ash destined for land application. PMID:24915641

  11. Will global warming affect soil-to-plant transfer of radionuclides?

    International Nuclear Information System (INIS)

    Recent assessments of global climate/environmental change are reaching a consensus that global climate change is occurring but there is significant uncertainty over the likely magnitude of this change and its impacts. There is little doubt that all aspects of the natural environment will be impacted to some degree. Soil-to-plant transfer of radionuclides has long been a significant topic in radioecology, both for the protection of humans and the environment from the effects of ionising radiation. Even after five decades of research considerable uncertainty exists as to the interplay of key environmental processes in controlling soil-plant transfer. As many of these processes are, to a lesser or greater extent, climate-dependent, it can be argued that climate/environmental change will impact soil-to-plant transfer of radionuclides and subsequent transfers in specific environments. This discussion attempts to highlight the possible role of climatic and climate-dependent variables in soil-to-plant transfer processes within the overall predictions of climate/environmental change. The work is speculative, and intended to stimulate debate on a theme that radioecology has either ignored or avoided in recent years

  12. Growth rate of bacteria is affected by soil texture and extraction procedure

    Czech Academy of Sciences Publication Activity Database

    Uhlířová, Eva; Šantrůčková, Hana

    2003-01-01

    Roč. 35, - (2003), s. 217-224. ISSN 0038-0717 Institutional research plan: CEZ:AV0Z6066911 Keywords : soil texture * extraction of bacteria * biosynthetic activity of bacteria Subject RIV: EH - Ecology, Behaviour Impact factor: 1.915, year: 2003

  13. Soil and Sediment Properties Affecting the Transport and Accumulations of Mercury in a Flood Control Reservoir

    Science.gov (United States)

    Mercury accumulations in some fish species from Grenada Lake in north Mississippi exceed the Food and Drug Administration standards for human consumption. This large flood control reservoir serves as a sink for the Skuna and Yalobusha River watersheds whose highly erodible soils contribute to exces...

  14. Soil processes affecting the presence of oxyfluorfen in surface and groundwaters of south Spain

    OpenAIRE

    Hermosín, M. C.; Calderón, M. J.; Cabrera Mesa, Alegría; Real Ojeda, Miguel; Koskinen, W. C.; Cornejo, J.

    2012-01-01

    Comunicación oral presentada al citado congreso, en la sesión W12.01b-5 - Pesticides in soil, fate and effects on environment - in collaboration with GRIFA. Celebrado del 2-6, julio, 2012, en Fiera del Levante, Bari, Italia.

  15. Saprotrophic basidiomycete mycelia and their interspecific interactions affect the spatial distribution of extracellular enzymes in soil

    Czech Academy of Sciences Publication Activity Database

    Šnajdr, Jaroslav; Dobiášová, Petra; Větrovský, Tomáš; Valášková, Vendula; Alawi, A.; Boddy, L.; Baldrian, Petr

    2011-01-01

    Roč. 78, č. 1 (2011), s. 80-90. ISSN 0168-6496 R&D Projects: GA MŠk LC06066; GA MŠk(CZ) OC10064 Institutional research plan: CEZ:AV0Z50200510 Keywords : decomposition * forest soil * fungal ecology Subject RIV: EE - Microbiology, Virology Impact factor: 3.408, year: 2011

  16. Soil Properties and Productivity as Affected by Topsoil Movement within an Eroded Landform

    Science.gov (United States)

    In hilly landforms subject to long-term cultivation, erosion has denuded upper slope positions of topsoil and accumulated topsoil in lower slope positions. One approach to remediate these eroded landforms is moving soil from areas of topsoil accumulation to areas of topsoil depletion, termed here so...

  17. Silver relase from decomposed hyperaccumulating Amanita solitaria fruit-body biomass strongly affects soil microbial community

    Czech Academy of Sciences Publication Activity Database

    Gryndler, M.; Hršelová, H.; Soukupová, L.; Borovička, Jan

    2012-01-01

    Roč. 25, č. 5 (2012), s. 987-993. ISSN 0966-0844 Institutional support: RVO:67985831 Keywords : soil fungi * bacteria * microbiota * heavy metals * toxicity * T-RFLP Subject RIV: DD - Geochemistry Impact factor: 3.284, year: 2012

  18. VINEYARD FLOOR MANAGEMENT STRATEGIES AFFECT SOIL PROPERTIES & MICROBIOLOGY, WATER RELATIONS, AND CROP NUTRITION

    Science.gov (United States)

    A long-term comparison of various vineyard floor management practices (weed control and cover crops) indicates that weed control treatments had no impact on soil microbial biomass, but had a significant interactive effect with the rye cover crop on mycorrhizal colonization of grapevine roots, presum...

  19. The sorption characteristics of mercury as affected by organic matter content and/or soil properties

    Science.gov (United States)

    Šípková, Adéla; Šillerová, Hana; Száková, Jiřina

    2014-05-01

    The determination and description of the mercury sorption extend on soil is significant for potential environmental toxic effects. The aim of this study was to assess the effectiveness of mercury sorption at different soil samples and vermicomposts. Mercury interactions with soil organic matter were studied using three soils with different physical-chemical properties - fluvisol, cambisol, and chernozem. Moreover, three different vermicomposts based on various bio-waste materials with high organic matter content were prepared in special fermentors. First was a digestate, second was represented by a mixture of bio-waste from housing estate and woodchips, and third was a garden bio-waste. In the case of vermicompost, the fractionation of organic matter was executed primarily using the resin SuperliteTM DAX-8. Therefore, the representation of individual fractions (humic acid, fulvic acid, hydrophilic compounds, and hydrophobic neutral organic matter) was known. The kinetics of mercury sorption onto materials of interest was studied by static sorption experiments. Samples were exposed to the solution with known Hg concentration of 12 mg kg-1 for the time from 10 minutes to 24 hours. Mercury content in the solutions was measured by the inductively coupled plasma mass spectrometry (ICP-MS). Based on this data, the optimum conditions for following sorption experiments were chosen. Subsequently, the batch sorption tests for all soil types and vermicomposts were performed in solution containing variable mercury concentrations between 1 and 12 mg kg-1. Equilibrium concentration values measured in the solution after sorption and calculated mercury content per kilogram of the soil or the vermi-compost were plotted. Two basic models of sorption isotherm - Langmuir and Freundlich, were used for the evaluation of the mercury sorption properties. The results showed that the best sorption properties from studied soil were identified in chernozem with highest cation exchange

  20. Bioavailability of xenobiotics in the soil environment.

    Science.gov (United States)

    Katayama, Arata; Bhula, Raj; Burns, G Richard; Carazo, Elizabeth; Felsot, Allan; Hamilton, Denis; Harris, Caroline; Kim, Yong-Hwa; Kleter, Gijs; Koedel, Werner; Linders, Jan; Peijnenburg, J G M Willie; Sabljic, Aleksandar; Stephenson, R Gerald; Racke, D Kenneth; Rubin, Baruch; Tanaka, Keiji; Unsworth, John; Wauchope, R Donald

    2010-01-01

    It is often presumed that all chemicals in soil are available to microorganisms, plant roots, and soil fauna via dermal exposure. Subsequent bioaccumulation through the food chain may then result in exposure to higher organisms. Using the presumption of total availability, national governments reduce environmental threshold levels of regulated chemicals by increasing guideline safety margins. However, evidence shows that chemical residues in the soil environment are not always bioavailable. Hence, actual chemical exposure levels of biota are much less than concentrations present in soil would suggest. Because "bioavailability" conveys meaning that combines implications of chemical sol persistency, efficacy, and toxicity, insights on the magnitude of a chemicals soil bioavailability is valuable. however, soil bioavailability of chemicals is a complex topic, and is affected by chemical properties, soil properties, species exposed, climate, and interaction processes. In this review, the state-of-art scientific basis for bioavailability is addressed. Key points covered include: definition, factors affecting bioavailability, equations governing key transport and distributive kinetics, and primary methods for estimating bioavailability. Primary transport mechanisms in living organisms, critical to an understanding of bioavailability, also presage the review. Transport of lipophilic chemicals occurs mainly by passive diffusion for all microorganisms, plants, and soil fauna. Therefore, the distribution of a chemical between organisms and soil (bioavailable proportion) follows partition equilibrium theory. However, a chemical's bioavailability does not always follow partition equilibrium theory because of other interactions with soil, such as soil sorption, hysteretic desorption, effects of surfactants in pore water, formation of "bound residue", etc. Bioassays for estimating chemical bioavailability have been introduced with several targeted endpoints: microbial

  1. Soil Science and Global Issues

    Science.gov (United States)

    Lal, Rattan

    2015-04-01

    Sustainable management of soil is integral to any rational approach to addressing global issues of the 21st century. A high quality soil is essential to: i) advancing food and nutritional security, ii) mitigating and adapting to climate change, iii) improving quality and renewability of water, iv) enriching biodiversity, v) producing biofuel feedstocks for reducing dependence on fossil fuel, and vi) providing cultural, aesthetical and recreational opportunities. Being the essence of all terrestrial life, soil functions and ecosystem services are essential to wellbeing of all species of plants and animals. Yet, soil resources are finite, unequally distributed geographically, and vulnerable to degradation by natural and anthropogenic perturbations. Nonetheless, soil has inherent resilience, and its ecosystem functions and services can be restored over time. However, soil resilience depends on several key soil properties including soil organic carbon (SOC) concentration and pool, plant-available water capacity (PWAC), nutrient reserves, effective rooting depth, texture and clay mineralogy, pH, cation exchange capacity (CEC) etc. There is a close inter-dependence among these properties. For example, SOC concentration strongly affects, PWAC, nutrient reserve, activity and species diversity of soil flora and fauna, CEC etc. Thus, judicious management of SOC concentration to maintain it above the threshold level (~1.5-2%) in the root zone is critical to sustaining essential functions and ecosystem services. Yet, soils of some agroecosystems (e.g., those managed by resources-poor farmers and small landholders in the tropics and sub-tropics) are severely depleted of their SOC reserves. Consequently. Agronomic productivity and wellbeing of people dependent on degraded soils is jeopardized. The ecosystem C pool of the terrestrial biosphere has been mined by extractive practices, the nature demands recarbonization of its biosphere for maintenance of its functions and

  2. Metal contamination of soils and crops affected by the Chenzhou lead/zinc mine spill (Hunan, China).

    Science.gov (United States)

    Liu, Hongyu; Probst, Anne; Liao, Bohan

    2005-03-01

    , and rice and capsicum had high Cd concentration in the edible parts. However, the toxic element concentrations in maize, sorghum, Adzuki bean, soybean and mung bean remained lower than the threshold levels. The bio-accumulation factors (BAFs) of crops were in the order: Cd>Zn>Cu>Pb>As. BAF was typically lower in the edible seeds or fruits than in stems and leaves. The accumulation effect strongly depends on the crop's physiological properties, the mobility, of the metals, and the availability of metals in soils but not entirely on the total element concentrations in the soils. Even so, the estimated daily intake amount of Cu, Zn, Cd, and Pb from the crops grown in the affected three sites and arsenic at SZY and GYB exceeded the RDA (Recommended dietary allowance) levels. Subsequently, the crops grown in Chenzhou Pb/Zn mine waste affected area might have a hazardous effect on the consumer's health. This area still needs effective measures to cure the As, Cd, Pb, Zn and Cu contamination. PMID:15740766

  3. Habitat management affects soil chemistry and allochthonous organic inputs mediating microbial structure and exo-enzyme activity in Wadden Sea salt-marsh soils

    Science.gov (United States)

    Mueller, Peter; Granse, Dirk; Thi Do, Hai; Weingartner, Magdalena; Nolte, Stefanie; Hoth, Stefan; Jensen, Kai

    2016-04-01

    The Wadden Sea (WS) region is Europe's largest wetland and home to approximately 20% of its salt marsh area. Mainland salt marshes of the WS are anthropogenically influenced systems and have traditionally been used for livestock grazing in wide parts. After foundation of WS National Parks in the late 1980s and early 1990s, artificial drainage has been abandoned; however, livestock grazing is still common in many areas of the National Parks and is under ongoing discussion as a habitat-management practice. While studies so far focused on effects of livestock grazing on biodiversity, little is known about how biogeochemical processes, element cycling, and particularly carbon sequestration are affected. Here, we present data from a recent field study focusing on grazing effects on soil properties, microbial exo-enzyme activity, microbial abundance and structure. Exo-enzyme activity was studied conducting digestive enzyme assays for various enzymes involved in C- and N cycling. Microbial abundance and structure was assessed measuring specific gene abundance of fungi and bacteria using quantitative PCR. Soil compaction induced by grazing led to higher bulk density and decreases in soil redox (∆ >100 mV). Soil pH was significantly lower in grazed parts. Further, the proportion of allochthonous organic matter (marine input) was significantly smaller in grazed vs. ungrazed sites, likely caused by a higher sediment trapping capacity of the taller vegetation in the ungrazed sites. Grazing induced changes in bulk density, pH and redox resulted in reduced activity of enzymes involved in microbial C acquisition; however, there was no grazing effect on enzymes involved in N acquisition. While changes in pH, bulk density or redox did not affect microbial abundance and structure, the relative amount of marine organic matter significantly reduced the relative abundance of fungi (F:B ratio). We conclude that livestock grazing directly affects microbial exo-enzyme activity, thus

  4. Signs of hypothetical fauna of Venus

    Science.gov (United States)

    Ksanfomality, Leonid V.

    2014-04-01

    On March 1 and 5, 1982, experiments in television photography instrumented by the landers VENERA-13 and -14, yielded 37 panoramas (or their fragments) of the Venus surface at the landing site. Over the past 31 years, no similar missions have been sent to Venus. Using a modern technique the VENERA panoramas were re-examined. A new analysis of Venusian surface panoramas' details has been made. A few relatively large objects of hypothetical fauna of Venus were found with size ranging from a decimeter to half meter and with unusual morphology. Treated once again VENERA-14 panoramic images revealed `amisada' object about 15 cm in size possessing apparent terramorphic features. The amisada's body stands out with its lizard-like shape against the stone plates close by. The amisada can be included into the list of the most significant findings of the hypothetical Venusian fauna. The amisada's body show slow movements, which is another evidence of the Venusian fauna's very slow style of activity, which appears to be associated with its energy constraints or, and that is more likely, with the properties of its internal medium. The terramorphic features of the Venusian fauna, if they are confirmed, may point out at outstandingly important and yet undiscovered general laws of the animated nature on different planets.

  5. Molecular techniques for identifying North Sea fauna

    OpenAIRE

    Knebelsberger, Thomas; Ditzler, Sandra; Laakmann, Silke; Mohrbeck, Inga; Raupach, Michael J.

    2010-01-01

    Accelerated biodiversity assessment is the key to understanding the relationship between biodiversity and ecosystem functioning, especially in times of rapid climate change and habitat destruction. For the marine fauna of the North Sea, morphological species identification is impaired by the small size of many taxa, morphological convergence, intraspecific variation and larval stages which often elude morphological identification. Accordingly, the use of molecular methods...

  6. The hawkmoth fauna of Pakistan (Lepidoptera: Sphingidae).

    Science.gov (United States)

    Rafi, Muhammad Ather; Sultan, Amir; Kitching, Ian J; Pittaway, Anthony R; Markhasiov, Maxim; Khan, Muhammad Rafique; Naz, Falak

    2014-01-01

    This study represents the first complete modern account of the Sphingidae of Pakistan and takes the form of an annotated checklist, based on several national collections and those of a number of individuals. Of the 60 species and subspecies found, 14 are new records to the fauna of Pakistan, namely Agnosia orneus, Langia zenzeroides subsp. zenzeroides, Polyptychus trilineatus subsp. trilineatus, Dolbina inexacta, Ambulyx sericeipennis subsp. sericeipennis, Thamnoecha uniformis, Macroglossum belis, Macroglossum stellatarum, Cechetra scotti, Hippotion boerhaviae, Hyles euphorbiae subsp. euphorbiae, Rhagastis olivacea, Rethera brandti subsp. euteles and Theretra latreillii subsp. lucasii. Anambulyx elwesi subsp. kitchingi and Clanis deucalion subsp. thomaswitti are not recognised as valid subspecies and are synonymized with their respective nominotypical subspecies. An additional list is given of 30 taxa which may yet be found in Pakistan as they are present in neighbouring countries close to the border. Of the species/subspecies found, 24 are part of the Palaearctic fauna, 27 are part of the Oriental fauna and nine are Palaeo-Oriental/Palaeotropical. This reconfirms the transitional biogeographical position of the Pakistan fauna. PMID:24870331

  7. Stand age and tree species affect N2O and CH4 exchange from afforested soils

    Directory of Open Access Journals (Sweden)

    P. Gundersen

    2011-09-01

    Full Text Available Afforestation of former agricultural land is a means to mitigate anthropogenic greenhouse gas emissions. The objectives of this study were (1 to assess the effect of oak (Quercus robur and Norway spruce (Picea abies [L.] Karst. stands of different stand ages (13–17 and 40 years after afforestation, respectively on N2O and CH4 exchange from the soil under these species and (2 identify the environmental factors responsible for the differences in gas exchange between tree species of different ages. N2O and CH4 fluxes (mean ± SE were measured for two years at an afforested site. No species difference was documented for N2O emission (oak: 4.2 ± 0.7 μg N2O-N m−2 h−1, spruce: 4.0 ± 1 μg N2O-N m−2 h−1 but the youngest stands (1.9 ± 0.3 μg N2O-N m−2 h−1 emitted significantly less N2O than older stands (6.3 ± 1.2 μg N2O-N m−2 h−1. CH4 exchange did not differ significantly between tree species (oak: −8.9 ± 0.9, spruce: −7.7 ± 1 or stand age (young: −7.3 ± 0.9 μg CH4-C m−2 h−1, old: −9.4 ± 1 μg CH4-C m−2 h−1 but interacted significantly; CH4 oxidation in the soil increased with stand age in oak and decreased with age for soils under Norway spruce. We conclude that the exchange of N2O and CH4 from the forest soil undergoes a quick and significant transition in the first four decades after planting in both oak and Norway spruce. These changes are related to (1 increased soil N availability over time as a result of less demand for N by trees in turn facilitating higher N2O production in older stands and (2 decreasing bulk density and increased gas diffusivity in the top soil over time facilitating better exchange of N2O and CH4 with the atmosphere.

  8. Hexachlorobenzene dechlorination as affected by organic fertilizer and urea applications in two rice planted paddy soils in a pot experiment

    International Nuclear Information System (INIS)

    Reductive dechlorination is a crucial pathway for HCB degradation, the applications of organic materials and nitrogen can alter microbial activity and redox potential of soils, thus probably influence HCB dechlorination. To evaluate hexachlorobenzene (HCB) dechlorination as affected by organic fertilizer (OF) and urea applications in planted paddy soils, a pot experiment was conducted in two types of soils, Hydragric Acrisols (Ac) and Gleyi-Stagnic Anthrosols (An). After 18 weeks of experiment, HCB residues decreased by 28.2-37.5% of the initial amounts in Ac, and 42.1-70.9% in An. The amounts of HCB metabolites showed that dechlorination rates in An were higher than in Ac, which was mainly attributed to the higher pH and dissolved organic carbon (DOC) content of An. Both in Ac and An, the additions of 1% and 2% OF had negative effect on HCB dechlorination, which was probably because excessive nitrogen in OF decreased degraders' activity and the degradation of organic carbon in OF accepted electrons. The application of 0.03% urea could enhance HCB dechlorination rates slightly, while 0.06% urea accelerated HCB dechlorination significantly both in Ac and An. It could be assumed that urea served as an electron donor and stimulated degraders to dechlorinate HCB. In addition, the methanogenic bacteria were involved in dechlorination process, and reductive dechlorination in planted paddy soil might be impeded for the aerenchyma and O2 supply into the rhizosphere. Results indicated that soil types, rice root system, methanogenic bacteria, OF and urea applications all had great effects on dechlorination process.

  9. Hexachlorobenzene dechlorination as affected by organic fertilizer and urea applications in two rice planted paddy soils in a pot experiment

    Energy Technology Data Exchange (ETDEWEB)

    Liu, C.Y. [State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008 (China); Jiang, X., E-mail: jiangxin@issas.ac.cn [State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008 (China); Yang, X.L.; Song, Y. [State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008 (China)

    2010-01-15

    Reductive dechlorination is a crucial pathway for HCB degradation, the applications of organic materials and nitrogen can alter microbial activity and redox potential of soils, thus probably influence HCB dechlorination. To evaluate hexachlorobenzene (HCB) dechlorination as affected by organic fertilizer (OF) and urea applications in planted paddy soils, a pot experiment was conducted in two types of soils, Hydragric Acrisols (Ac) and Gleyi-Stagnic Anthrosols (An). After 18 weeks of experiment, HCB residues decreased by 28.2-37.5% of the initial amounts in Ac, and 42.1-70.9% in An. The amounts of HCB metabolites showed that dechlorination rates in An were higher than in Ac, which was mainly attributed to the higher pH and dissolved organic carbon (DOC) content of An. Both in Ac and An, the additions of 1% and 2% OF had negative effect on HCB dechlorination, which was probably because excessive nitrogen in OF decreased degraders' activity and the degradation of organic carbon in OF accepted electrons. The application of 0.03% urea could enhance HCB dechlorination rates slightly, while 0.06% urea accelerated HCB dechlorination significantly both in Ac and An. It could be assumed that urea served as an electron donor and stimulated degraders to dechlorinate HCB. In addition, the methanogenic bacteria were involved in dechlorination process, and reductive dechlorination in planted paddy soil might be impeded for the aerenchyma and O{sub 2} supply into the rhizosphere. Results indicated that soil types, rice root system, methanogenic bacteria, OF and urea applications all had great effects on dechlorination process.

  10. Carbon-allocation dynamics in reed canary grass as affected by soil type and fertilization rates in northern Sweden

    Energy Technology Data Exchange (ETDEWEB)

    Shaojun Xiong (Unit of Biomass Technology and Chemistry, Swedish Univ. of Agricultural Sciences, Umeaa (Sweden)); Kaetterer, Thomas (Dept. of Soil and Environment, Swedish Univ. of Agricultural Sciences, Uppsala (Sweden))

    2010-01-15

    A field experiment was conducted in northern Sweden between 1995 and 1997, with the objectives (1) to quantify the dynamics of carbon accumulation in above- and below ground crop components of reed canary grass (RCG) during the second and third year after sowing and (2) to examine the effect of fertilization and soil type (mineral vs. organic) on C allocation. Across all treatments, carbon accumulation in below ground organs in the top 20 cm was on average 3 and 3.4 Mg C by the end of the second and third year, respectively, with roots and rhizomes accounting for up to 80%. Roots contributed most to below ground C mass during the second growing season but during the preceding winter, root biomass C decreased by 44-67%, and, thereafter, during the third growing season, the proportion of rhizome C increased. The dynamics of root biomass was considerably high, suggesting high root turnover rates. Rhizomes support re-growth during spring and rhizome biomass seems to increase with crop age. Thus, early harvesting before October may impact on the productivity during the following season. Among the factors studied, harvest date was the most influential and affected C allocation in all crop components considerably. Fertilization stimulated growth of shoots, rhizomes, and BSBs (below ground shoot bases) but not that of roots. However, root biomass was higher in the organic than in the mineral soil. In this study, we considered only plant components above 20 cm depth. More detailed studies are needed to calculate more complete soil C balances. However, high below ground biomass production and root turnover indicate a high C input to the soil, which may result in positive soil C balances. Therefore, RCG cropping could have considerable carbon-sequestration potential

  11. Soil organic carbon sequestration as affected by afforestation: the Darab Kola forest (north of Iran) case study.

    Science.gov (United States)

    Kooch, Yahya; Hosseini, Seyed Mohsen; Zaccone, Claudio; Jalilvand, Hamid; Hojjati, Seyed Mohammad

    2012-09-01

    Following the ratification of the Kyoto Protocol, afforestation of formerly arable lands and/or degraded areas has been acknowledged as a land-use change contributing to the mitigation of increasing atmospheric CO(2) concentration in the atmosphere. In the present work, we study the soil organic carbon sequestration (SOCS) in 21 year old stands of maple (Acer velutinum Bioss.), oak (Quercus castaneifolia C.A. Mey.), and red pine (Pinus brutia Ten.) in the Darab Kola region, north of Iran. Soil samples were collected at four different depths (0-10, 10-20, 20-30, and 30-40 cm), and characterized with respect to bulk density, water content, electrical conductivity, pH, texture, lime content, total organic C, total N, and earthworm density and biomass. Data showed that afforested stands significantly affected soil characteristics, also raising SOCS phenomena, with values of 163.3, 120.6, and 102.1 Mg C ha(-1) for red pine, oak and maple stands, respectively, vs. 83.0 Mg C ha(-1) for the control region. Even if the dynamics of organic matter (OM) in soil is very complex and affected by several pedo-climatic factors, a stepwise regression method indicates that SOCS values in the studied area could be predicted using the following parameters, i.e., sand, clay, lime, and total N contents, and C/N ratio. In particular, although the chemical and physical stabilization capacity of organic C by soil is believed to be mainly governed by clay content, regression analysis showed a positive correlation between SOCS and sand (R = 0.86(**)), whereas a negative correlation with clay (R = -0.77(**)) was observed, thus suggesting that most of this organic C occurs as particulate OM instead of mineral-associated OM. Although the proposed models do not take into account possible changes due to natural and anthropogenic processes, they represent a simple way that could be used to evaluate and/or monitor the potential of each forest plantation in immobilizing organic C in soil (thus

  12. Five-year changes in soil organic carbon and total nitrogen in coastal wetlands affected by flow-sediment regulation in a Chinese delta

    Science.gov (United States)

    Wang, Junjing; Bai, Junhong; Zhao, Qingqing; Lu, Qiongqiong; Xia, Zhijian

    2016-01-01

    Changes in the sources and sinks of soil organic carbon (SOC) and total nitrogen (TN) in wetland soils as indicators of soil quality and climate change have received attention worldwide. Soil samples were collected in 2007 and 2012 in the coastal wetlands of the Yellow River Delta and the SOC and TN were determined to investigate a five-year change in their content and stock in these wetlands as affected by flow-sediment regulation. Our results revealed that the soils in 2007 exhibited greater electrical conductivities, SOC content and density, and ammonium nitrogen (NH4+-N) levels in the top 10 cm soils (p < 0.05) compared with the soils in 2012. In general, the SOC and TN contents decreased with increasing soil depth. However, the highest ratios of soil organic carbon and total nitrogen (molar C/N ratios) were observed in the 30–40 cm soil layer. A significant SOC loss occurred (p < 0.05) in top 10 cm soils, but only a small change in SOC in the top 50 cm soils. Comparatively, TN levels did not show significant differences in the study period. PMID:26879008

  13. Effects of suction-dredging for cockles on non-target fauna in the Wadden Sea

    NARCIS (Netherlands)

    Hiddink, JG

    2003-01-01

    Suction dredging for cockles removes large cockles from tidal flats and may also cause mortality of non-target fauna and make the habitat less suitable for some species. This study examines whether suction dredging for cockles on tidal flats of the Dutch Wadden Sea had affected densities of non-targ

  14. Using Saline Water in Salt Affected Soils to Enhance Food Productivity and Farmer Incomes in Bangladesh

    International Nuclear Information System (INIS)

    Bangladesh is a deltaic country with a total area of 147,570 km2, agriculture accounting for a major sector of the national economy. The coastal regions that occupy about 20% of the country's land area are very fertile and are used primarily to grow rice. During the rice season