Littérature scientifique sur le sujet « Biological soil quality »
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Articles de revues sur le sujet "Biological soil quality"
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Visser, Suzanne, et Dennis Parkinson. « Soil biological criteria as indicators of soil quality : Soil microorganisms ». American Journal of Alternative Agriculture 7, no 1-2 (juin 1992) : 33–37. http://dx.doi.org/10.1017/s0889189300004434.
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AbstractDiverse soil microbiological studies have attempted to assess deterioration or improvement in soil quality. These studies have been done on three levels: population level studies of the dynamics of species that are presumed to be important or sensitive; community level studies of microbial community structure, such as species diversity and frequency of occurence of species; and ecosystem level studies of a range of soil processes. We suggest that ecosystem level approaches offer the best possibilities for rapidly assessing changes in soil quality. Data from such studies will allow researchers to decide whether to proceed with population or community level studies.
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Duffková, R., et H. Macurová. « Soil biological quantity and quality parameters of grasslands in various landscape zones ». Plant, Soil and Environment 57, No. 12 (1 décembre 2011) : 577–82. http://dx.doi.org/10.17221/475/2011-pse.
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In three landscape zones of a permanent grassland catchment (discharge zone, D; transient zone, T; and recharge zone, R; Crystallinicum, Czech Republic), soil moisture by volume (θ) and soil biological quantity and quality parameters, e.g. oxidizable C (C<sub>ox</sub>), hot water soluble C (C<sub>hws</sub>), microbial biomass C (C<sub>mic</sub>), nitrification (NITR), aerobic N mineralization (MIN) and basal respiration rates (R<sub>bas</sub>), metabolic quotient (qCO<sub>2</sub>: R<sub>bas</sub>/C<sub>mic</sub>) and microbial quotient (C<sub>mic</sub>/C<sub>ox</sub>) were estimated in the surface soil layer. We found out positive correlation of C<sub>mic</sub> and C<sub>mic</sub>/C<sub>ox</sub> with θ, or NITR, MIN, R<sub>bas</sub> and C<sub>mic</sub> with C<sub>hws</sub>, but no relationship between θ on the one hand and NITR, MIN, R<sub>bas</sub> or C<sub>ox</sub> on the other. The wettest zone D with extremely low pH displayed the highest C<sub>mic</sub> and C<sub>mic</sub>/C<sub>ox</sub> (1081 mg/kg, 5.29%) and the lowest qCO<sub>2</sub> (31 µgC/day/mgC<sub>mic</sub>). Soil drought in zones T and R reduced C<sub>mic</sub> and C<sub>mic</sub>/C<sub>ox</sub> (939, 1029, and 3.72, 3.83, respectively) and augmented qCO<sub>2</sub> (42; 51). Rainfall following a prolonged dry period reduced MIN and NITR in permeable zone R as a result of fast microbial regeneration (average in D: 2.24; 2.48 kg N/ha/day, T: 2.62; 2.82 kg N/ha/day, R: 1.51; 1.95 kg N/ha/day).
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Stockdale, E. A., et C. A. Watson. « Biological indicators of soil quality in organic farming systems ». Renewable Agriculture and Food Systems 24, no 4 (19 novembre 2009) : 308–18. http://dx.doi.org/10.1017/s1742170509990172.
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AbstractThe health of the soil, recognized by its active role in the linked processes of decomposition and nutrient supply, is considered as the foundation of agriculture by the organic farming movement. Nutrient management in organically managed soils is fundamentally different from that of conventional agricultural systems. Crop rotations are designed with regard to maintenance of fertility with a focus on nutrient recycling. Where nutrients are added to the system, inputs are in organic and/or non-synthetic fertilizer sources that are mostly slow release in nature. Hence a greater reliance is placed on soil chemical and biological processes to release nutrients in plant-available forms. In this respect, nutrient availability in organically farmed soils is more dependent upon soil processes than is the case in conventional agriculture. The development and use of biological indicators of soil quality may therefore be more important in organic (and other low input) farming systems. The aim of this paper is to evaluate current evidence for the impact of organic farming systems on soil biological quality and consider the identification of appropriate biological indicators for use by organic farmers and their advisors. Organic farming systems are generally associated with increased biological activity and increased below-ground biodiversity. The main impacts on biological fertility do not result from the systemsper sebut are related to the amount and quality of the soil organic matter pool and disruptions of soil habitat via tillage. Even within the constraints of organic farming practices it is possible for farmers to make changes to management practices which will tend to improve soil biological quality. It is, however, by no means clear that distinct indicators of soil biological quality are needed for organic farming systems. It is important not only to identify the most appropriate indicators but also to ensure that farmers and land managers can understand and relate to them to support on-farm management decisions.
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Maienza, Anita, Fabrizio Ungaro, Silvia Baronti, Ilaria Colzi, Laura Giagnoni, Cristina Gonnelli, Giancarlo Renella, Francesca Ugolini et Costanza Calzolari. « Biological Restoration of Urban Soils after De-Sealing Interventions ». Agriculture 11, no 3 (25 février 2021) : 190. http://dx.doi.org/10.3390/agriculture11030190.
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Most urban greening interventions involve soil de-sealing and management to enhance fertility. Management typically requires translocating fertile topsoil to the site, which comes at great environmental costs. We hypothesized that de-sealed urban soils would undergo an increase of their fertility without exogenous topsoil application. We assessed experimental plots with de-sealed soil with topsoil, and de-sealed soil without topsoil. Both treatments were vegetated with two ornamental shrub species and irrigated. Soil fertility was analyzed by chemical (total and organic carbon) and biological indicators of soils (biological quality index and microbial activities). Since metal contamination is related to urban de-sealed soil, we also monitored the concentration of Zn, Cu and Pb in soil and detected it in plant leaves. The results demonstrate that de-sealed urban soils rapidly restore their biological quality and fertility. Restoration of de-sealing soils can contribute to the recent growing interest reclamation of urban soils for improving the urban environment quality through the restoration of soil functions and related ecosystem services. Overall, the results of this study demonstrate that de-sealed soils can improve their functionality and can contribute to the recent growing interest in reclamation of urban soils for improving the urban environment quality.
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Stork, Nigel E., et Paul Eggleton. « Invertebrates as determinants and indicators of soil quality ». American Journal of Alternative Agriculture 7, no 1-2 (juin 1992) : 38–47. http://dx.doi.org/10.1017/s0889189300004446.
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AbstractInvertebrates are an integral part of soils and are important in determining the suitability of soils for the sustainable production of healthy crops or trees. We discuss the importance of the soil invertebrate fauna in relation to terrestrial habitats and global biodiversity as we understand it. We describe the role of the main invertebrate groups in soils, including earthworms, termites, springtails, and nematodes, and how they determine soil quality. Practical problems in dealing with the invertebrate fauna include sampling, taxonomy and availability of biological information on species. Various measures are available that use invertebrates to assess soil quality, each with its advantages and disadvantages. They include abundance, biomass, density, species richness, trophic/guild structure, food web structure, keystone species and ecosystem engineers. We propose the three most useful and practical of these as suitable to be combined with other biological (microbial) and non-biological (hydrological, physical, chemical) criteria into a single index of soil quality that might be used on a regional, if not international basis.
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Błońska, Ewa, et Jarosław Lasota. « Biological and biochemical properties in evaluation of forest soil quality ». Folia Forestalia Polonica 56, no 1 (1 mars 2014) : 23–29. http://dx.doi.org/10.2478/ffp-2014-0003.
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Abstract The aim of this study was to assess the possibility of using biological and biochemical parameters in the evaluation of forest soil quality and changes caused by land use. The study attempted to determine a relationship between the enzymatic activity of soil, the number of earthworms and soil physico-chemical properties. The study was carried out in central Poland in adjoining Forest Districts (Przedbórz and Smardzewice). In soil samples taken from 12 research plots, basic physico-chemical properties, enzyme activity (dehydrogenase, urease) and density and biomass of earthworms were examined. Enzyme activity showed a large diversity within the forest site types studied. The correlations between the activity of the enzymes studied and C/N ratio indicated considerable importance of these enzymes in metabolism of essential elements of organic matter of forest soils. Urease and dehydrogenase activity and earthworm number showed susceptibility to soil pH, which confirmed relationships between enzyme activity and abundance of earthworms and soil pH in H2O and KCl.
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Oliveira, Sofia S., Joana Pereira, Paulo Santos et Ruth Pereira. « Assessing Soil Quality in Schoolyards ». American Biology Teacher 83, no 5 (1 mai 2021) : 331–36. http://dx.doi.org/10.1525/abt.2021.83.5.331.
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Soil provides innumerable valuable ecosystem services, such as the production of food and the direct support of wildlife, by ensuring the availability of adequate habitat. However, unsustainable human activities are resulting in degradation of soils worldwide. Hence, it is of utmost importance to raise awareness about this often-overlooked environmental issue. This article presents an inquiry-based activity that challenges students to assess the ecological quality of soil in the surroundings of their classroom. Plus, students and teachers are invited to become citizen scientists by sharing their data with researchers, thus contributing to a future endeavor to map soil quality through broad geographic ranges.
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Aravindh, Selvaraj, Chinnappan Chinnadurai et Dananjeyan Balachandar. « Development of a soil biological quality index for soils of semi-arid tropics ». SOIL 6, no 2 (9 octobre 2020) : 483–97. http://dx.doi.org/10.5194/soil-6-483-2020.
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Abstract. Agricultural intensification, an inevitable process to feed the ever-increasing population, affects soil quality due to management-induced changes. To measure the soil quality in terms of soil functioning, several attempts were made to develop a soil quality index (SQI) based on a set of soil attributes. However, there is no universal consensus protocol available for SQI, and the role of soil biological indicators in SQI is meagre. Therefore, the present work aims to develop a unitless soil biological quality index (SBQI) scaled between 0 and 10, which would be a major component of SQI in the future. The long-term organic manure amended (OM), integrated nutrient management enforced (INM), synthetic fertilizer applied (IC), and unfertilized control (control) soils from three different predominant soil types of the location (Tamil Nadu state, India) were chosen for this. The soil organic carbon, microbial biomass carbon, labile carbon, protein index, dehydrogenase activity, and substrate-induced respiration were used to estimate the SBQI. Five different SBQI methods, viz. simple additive (SBQI1 and SBQI2), scoring function (SBQI3), principal component analysis-based statistical modelling (SBQI4), and quadrant-plot-based method (SBQI5), were developed to estimate the biological quality as a unitless scale. All five methods have the same resolution to discriminate the soils and INM ≈ OM > IC > control is the relative trend being followed in all the soil types based on the SBQIs. All five methods were further validated for their efficiency in 25 farmers' soils of the location and proved that these methods can scale the biological health of the soil. Among the five SBQIs, we recommend SBQI5, which relates the variables to each other to scale the biological health of the soil.
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Toledo, Marcela, Silvia Ama Arzuaga, Stella Maris Contreras Leiva et Sara Vazquez. « Biological indicators of soil quality in natural and cultivated subtropical systems ». JOURNAL OF ADVANCES IN AGRICULTURE 4, no 2 (29 mai 2015) : 392–97. http://dx.doi.org/10.24297/jaa.v4i2.4269.
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The objective of this work was to evaluate the effects of forest conversion at to agricultural production on some biological indicators to quantify their relationship in subtropical ecosystems. The experimental design was in romized complete blocks, with four treatments: subtropical rainforest (F), yerba mate crops (I) (Ilex paraguariensis SH.); citrus crops (C) (Citrus unshiu Marc.); tobacco crops (T) (Nicotiana tabacum L.). Soil samples were taken from 0-0.10, 0.10-0.20, 0.20-0.30m deep. The variables measured were: APA, clay content, pH, total nitrogen (N), available phosphorus (P), respiration (RE) soil organic carbon (SOC). These soils showed an acid reaction clay content over 650 g.kg-1. SOC N content were higher in soils under subtropical rainforest, intermediate under citrus crops, lower under tobacco yerba mate crops. The highest APA was found under subtropical rainforest decreased in the three depths. In all treatments, APA was higher in the superficial layer; the 76% of APA variability was explained by N P. APA can indicate changes in soil quality, when comparing subtropical rainforest to agricultural systems. APA does not indicate effects between soils under different crops. Our data suggest that acid phosphatase activity is closely associated to soil nitrogen organic content as energy source.Â
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Franzluebbers, A. J., R. L. Haney, F. M. Hons et D. A. Zuberer. « Assessing biological soil quality with chloroform fumigation-incubation : Why subtract a control ? » Canadian Journal of Soil Science 79, no 4 (1 novembre 1999) : 521–28. http://dx.doi.org/10.4141/s99-010.
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Microbial biomass, as part of the active pool of soil organic matter, is critical in decomposition of organic materials, nutrient cycling, and formation of soil structure. We evaluated chloroform fumigation-incubation with subtraction of a control (CFI/F–C) and without subtraction of a control (CFI/F) as methods to assess biological soil quality. Relationships between CFI/F and potential C mineralization, particulate organic C, and soil organic C were stronger (r2 = 0.86 ± 0.07, n = 232) than those between CFI/F–C and the same soil C pools (r2 = 0.25 ± 0.09) in soils from Georgia. From published data, relationships of CFI/F with potential C mineralization and soil organic C were stronger than those of chloroform fumigation-extraction and substrate-induced respiration with these soil C pools. Effects of land management on biological soil quality using CFI/F were consistent with those determined using other soil C pools as response variables. However, land management effects on biological soil quality using CFI/F–C were either contrary to those using other soil C pools or not detectable because of greater inherent variability in CFI/F–C. Chloroform fumigation-incubation without subtraction of a control is a robust and reliable method to assess biological soil quality under a wide range of soil conditions. Key words: Active soil carbon, chloroform fumigation-extraction, microbial biomass, soil organic matter, soil quality, substrate-induced respiration
Thèses sur le sujet "Biological soil quality"
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Netherton, Marks Evan Alexander. « Biochar effects on soil quality as evaluated by physical, chemical, and biological parameters ». Doctoral thesis, Universitat Autònoma de Barcelona, 2013. http://hdl.handle.net/10803/131325.
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El biochar es un producto resultante de la descomposición térmica mediante pirolisis de biomasa y aplicado al suelo para mejorar sus propiedades. Este area de investigación está auge actualmente por su papel en mejorar la práctica agrícola y como estrategia de secuestro de carbono en suelo. Aún siendo un campo joven, poco se sabe sobre su idoneidad a largo plazo, y aún no se ha estudiado suficientemente sus posibles efectos negativos sobre la calidad del suelo, incluyendo la biología del suelo.
Esta tesis toma como enfoque métodos biológicos para evaluar el impacto de biochar sobre la calidad del suelo. Una parte importante de la tesis se basa en bioensayos de laboratorio, complementados por un estudio de campo para evaluar de manera realista los efectos de biochar en un agroecosistema.
Los bioensayos realizados a seis biochars demostraron que el método de producción tiene un impacto importante sobre las propiedades químicas del suelo, y a su vez la respuesta de las plantas. Los biochars de gasificación y pirólisis rápida indujeron inhibición vegetal a concentraciones realistas, mientras biochars de pirólisis lenta generalmente no afectaron a las plantas. La inhibición fue interpretada como consecuencia de efectos a corto plazo sobre la disponibilidad de nutrientes en algunos biochars, debido a sus elevados contenidos de materia volátil, que estimularían el crecimiento de microorganismos y la inmobilización de N, mientras que en los biochar más alcalinos se sospechó que fueron debidos a una reducción de la disponibilidad de P.
En tests con invertebrados, las respuestas de colémbolos y enquitreidos han sido muy similares, con estimulación en el biochar de lodos de depuradora y de inhibición en el de astilla de pino producido por gasificación. Los resultados señalan el papel de la alcalinización como causándote de los efectos directos en mortalidad y de reproducción. No se pudo demostrar que el estímulo de la comunidad microbiana causado por el biochar explicara la estimulación de la reproducción de la mesofauna observada en algunos biochars.
Se desarrolló un nuevo parámetro de medida del impacto para los colémbolos basado en la biomasa de juveniles y su estructura de tamaños mediante el ajuste a modelos multi-Gaussianos. Los incrementos en el número de clases de edad, acompañados por incrementos en la biomasa y longitud de individuos, han sido interpretados como efectos estimulatorios, mientras, a su vez, su diminución ha se interpretó como efectos inhibitorios.
Finalmente, en un experimento de campo simulando un cultivo de cebada enmendado con un biochar de pino producido por gasificación, se han demostrado efectos positivos sobre propiedades físicas del evaluadas. Los efectos sobre las propiedades químicas fueron menos marcados, pero son destacables los incrementos en las concentraciones K+, y la reducción de las de NO3-. El cultivo fue generalmente estimulado a 12 t ha-1, y generalmente inhibido a 50 t ha-1. La actividad de mesofauna fue impactada negativamente a 50 t ha-1 biochar. La adición de biochar permitió aumentos significativos en la abundancia microbiana pero no en su actividad, indicando un aumento de su eficiencia.
Ensayos de laboratorio de mineralización de material vegetal indicaron que el biochar reducía la liberación de NO3-. Globalmente, el estudio de campo ha demostrado que biochar puede mejorar la fertilidad del suelo a aplicaciones moderadas, pero puede disminuir la calidad del suelo a aplicaciones altas.
Los resultados de esta tesis contribuyen a la escasa información disponible sobre los efectos del biochar sobre la biota del suelo, así como los beneficios y riesgos en suelos alcalinos bajo clima mediterréneos.Biochar is thermally-decomposed biomass deliberately applied to soil to improve its properties. In recent years, biochar research has grown immensely for its potential role in improving agricultural practices and as a strategy to sequester carbon in the soil. However, as a young scientific field of study, little is proven about biochar’s long-term compatibility with modern agriculture, and there is still major uncertainty about its potential negative impacts on soil quality, information on biochar’s effects on soil biology is quite limited. Biochar’s effects on soil quality is the topic of the thesis, with an emphasis on biological methods for its evaluation. A substantial portion of this thesis is based on ecotoxicological approaches of evaluation. Laboratory bioassay studies were undertaken, and complementary studies were undertaken in the field for a broader evaluation of effects in a more realistic setting. Plant growth tests with six biochars showed that pyrolysis method had a strong influence on chemical properties affecting plant responses. Gasification and fast-pyrolysis chars were strongly inhibitory at realistic application rates, while slow-pyrolysis chars generally did not affect plant growth. Inhibition was interpreted to be due to short-term effects on nutrient plant availability, due to biochar’s volatile matter content which increases competition with microorganisms, and P content and/or effects on P availability. In tests with soil invertebrates, performance of the Collembolan and enchytraeid were analogous for both the sewage sludge and pine gasification char, which were slightly stimulatory and inhibitory, respectively. Our results suggest alkalization-related increases in mortality and inhibition of reproduction. We hypothesized that increased microbial abundance would explain stimulation of fauna performance, but this showed no clear trend with biochar concentration, providing no evidence for a trophic effect. Also, Collembolan juvenile biomass and size class structure endpoints were developed using a multi-Gaussian fitting approach. Increases in number of size classes, accompanied by greater relative allocation of biomass to individuals of larger somatic length, were interpreted as stimulatory conditions, and reduction in the number of classes and proportional representation of larger classes were associated with inhibitory effects. Finally, in the field study, simulating barley cultivation with amendment of a gasification biochar, effects on soil physical properties were generally positive. Measured soil chemical parameters were not strongly affected, with the exception of increased K+ ¬ and decreased NO3-. The barley crop was generally stimulated at 12 t ha-1, and generally inhibited at 50 t ha-1. Mineralization tests showed that biochar also reduced NO3- transformation. Overall, the field study that the biochar can enhance soil quality at moderate application rates, but can decrease soil quality at higher rates. Also, fauna activity was negatively impacted at the high, 50 t ha-1 application rate. The addition of biochar permitted increases in microbial abundance, but not activity, indicating an increase in efficiency. These results all have served to provide basic information on effects of biochar on soil quality, whereas to date little information has been available either for soil biota or in mediterranean or alkaline soils.
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D'AMICO, MICHELE EUGENIO. « Soil ecology and pedogenesis on ophiolitic materials in the western Alps (Mont Avic Natural Park, North-western Italy) : soil properties and their relationships with substrate, vegetation and biological activity ». Doctoral thesis, Università degli Studi di Milano-Bicocca, 2009. http://hdl.handle.net/10281/10401.
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Soils formed from ultramafic rocks are normally by pH values close to neutrality, a high base status and are usually rich in Mg, Fe and heavy metals. The low Ca/Mg ratio and the high heavy metal content could cause toxic effects in the biological communities. Plant communities, in particular, are usually different from nearby areas with different substrates and rich in endemisms and adapted species and subspecies.
Despite their great environmental and ecological interest, pedological and ecological properties of mountain or boreal soils developed on similar substrates have seldom been studied worldwide. 198 soil pits (associated with phytosociological surveys) have been opened and analyzed in the ophiolitic area of Mont Avic Natural Park (Val d’Aosta, Western Alps, Italy), beween 900 and 2900 m above see level. Soils formed from ultramafic, mafic rocks and calcschists have been observed, in order to recognize the most ecologically important soil factors.
The results show that soil properties are related with altitude and slope aspect in forest habitats, while the effect of substrate becomes important above timberline. Strong leaching in forest soils, related to high acidity and to the podzolization process, decrease the total and bioavailable heavy metal contents, above the treeline pedogenic and geomorphic processes release and accumulate large quantities of potentially hazardous trace elements. The plant communities strictly depend on the edaphic properties above the treeline, while in the forest habitats the differences caused by substrate are less discernible.
Microbial and microarthropodal communities suffer stress caused by heavy metals in forest soils, while at the alpine level non significant statistical or ecological correlation are visible.
Heavy metals (Ni, in particular) are the most important edaphic properties in differentiating plant communities on different substrata, while the Ca/Mg ratio (usually considered the most influencing soil properties on ultramafic soils) has no particular ecological effect.
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Ge, Yufeng. « Mapping in-field cotton fiber quality and relating it to soil moisture ». Thesis, [College Station, Tex. : Texas A&M University, 2007. http://hdl.handle.net/1969.1/ETD-TAMU-1425.
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Law, Audrey. « EVALUATING THE EFFECTS OF ORGANIC AND CONVENTIONAL INPUTS ON SOIL CHEMICAL AND BIOLOGICAL PROPERTIES IN A FOUR-YEAR VEGETABLE ROTATION AND THE INVESTIGATION OF SOIL MICROBIAL PROPERTIES ON PLANT GENE EXPRESSION ». UKnowledge, 2009. http://uknowledge.uky.edu/gradschool_diss/704.
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The objective of this research was to determine the effects of conventional inputs on soil chemical and biological properties compared to organic systems in a four year vegetable rotation. Tillage and cover crops were the same in all treatments to avoid confounding factors often present in similar research. Additional experiments investigated plant gene expression in organic and conventional management systems and in soils with decreased microbial diversity. Experimental plots were prepared in the spring of 2004; four replications of three management treatments, organic, low-input and conventional, were arranged in a randomized complete block design. The rotation consisted of edamame soybean, sweet corn, fallow (pastured poultry in organic plots), and potatoes. Soil samples were taken in the spring and fall of each year, along with data for pest damage, weed control, yield and quality. Soil samples were analyzed for enzyme activity (maximum activity under substrate saturation) and basic soil chemical properties. Treatments were compared over time using 2-Way ANOVA. Multiplex terminal-restriction fragment length polymorphism (M-TRFLP) profiles of the soil microbial community were compared using Multiple Response Permutation Procedures (MRPP). Multi-way ANOVA detected significant treatment effects over time in total carbon, nitrogen, Mehlich III K, Exchangeable K and exchangeable Na (p=0.05). Many significant changes in soil properties over time could not be attributed to treatment effects. All treatments produced similar yields, indicating that successful organic production of these vegetables is possible in Kentucky. Input costs for organic were 37% higher than conventional, due to the cost of organic fertilizer. The organic system required nearly 50% more labor hours than conventional or low-input. The low-input system was the most cost effective, with 58% less input expenses than the conventional system. Microarray analysis of approximately 37,500 Glycine max transcripts did not show significant differences in the gene expression between plants grown organically and conventionally, in plots with significant soil chemical and microbial differences. An experiment in progress is investigating changes in plant gene expression using real time RT-PCR in tomatoes grown in autoclaved soil and native field soil.
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Human, Hans Jurie. « Identification of soil and biological factors in crop rotation systems with significance to wheat crop performance in the Overberg production area of South Africa ». Thesis, Link to the online version, 2008. http://hdl.handle.net/10019.1/2286.
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Timmerman, Mitchell D. « The effects of a crude oil spill on the crop productivity and biological quality of an agricultural soil, and the potential for phytoremediation of crude oil-contaminated land ». Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape8/PQDD_0006/MQ45127.pdf.
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Sousa, Heiriane Martins. « Atributos microbiológicos do solo em sistemas de integração lavoura-pecuária no ecótono Cerrado-Amazônia ». Universidade Federal de Mato Grosso, 2014. http://ri.ufmt.br/handle/1/477.
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O sistema de integração Lavoura-Pecuária (iLP), é uma alternativa de conservação dos recursos naturais. Sua característica principal é incluir culturas anuais e pastagens em uma mesma área, com objetivos de aumentar os lucros, manter e ou melhorar os atributos químicos, físicos e biológicos do solo. O objetivo deste trabalho foi avaliar os atributos microbiológicos do solo e sua resiliência, como indicadores de qualidade, em sistemas de iLP, no Ecótono Cerrado-Amazônia no estado de Mato Grosso. Amostras de solo, foram coletadas em 5 conformações de iLP, uma mata nativa e uma sucessão de culturas (soja/milho), no período de chuva, em duas épocas (2012 e 2013). Por meio da análise univariada dos dados, observou-se que as variáveis microbiológicas (carbono da biomassa microbiana = CBM; respiração basal; quociente metabólico; atividade das enzimas β-glicosidase, fosfatase alcalina e ácida, urease; enumeração de micro-organismos celulolíticos, actinomicetos, bactérias e fungos do solo) foram influenciadas pelos sistemas e épocas de coletas. A segunda época de coleta (2013), em geral resultou-se em maiores resultados nos atributos microbiológicos. Os maiores teores de CBM foram observados nos sistemas com maior diversificação da matéria orgânica, como na mata nativa e na iLP A (sistema que de 2005-2009 se manteve com 3 culturas anuais e de 2009-2011 com Brachiaria brizantha ). Os sistemas modificaram a atividade das enzimas. Sendo que, dois sistemas de iLP se assemelharam com a mata nativa, esta por sua vez, apresentou-se mais estável na produção de enzimas que os demais sistemas. As populações de micro-organismos foram afetadas pelos sistemas, mas diferentemente das enzimas, os resultados foram maiores nas iLP do que no sistema referencial. Na análise multivariada, os sistemas apresentaram resultados homogêneos e se agruparam formando um grupo em 2012. Houve uma segregação destes sistemas em 2013, onde formaram 2 grupos com funções similares sobre as variáveis. A partir de um desses grupos foi possível identificar que a iLP C e iLP A foram os sistemas que mais assemelharam com a mata nativa, tal fato comprova que a iLP corrobora para com a melhoria e/ou manutenção dos atributos microbiológicos. Os fatores climáticos tiveram alta influência sobre os resultados. A enzima β-glicosidade apresentou forte correlação sobre as demais enzimas. As variáveis microbiológicas analisadas isoladamente são sensíveis às alterações em função do uso do solo e do tempo, e são bons indicadores de qualidade do solo. A época de coleta influenciou os resultados microbiológicos. O sistema integrado de produção proporciona resiliência na estrutura e função da microbiota do solo, sendo uma ferramenta de manejo menos impactante e com maior capacidade de sustentabilidade do componente microbiológico do solo.
The Crop-Livestock (iLP) system integration is an alternative for the conservation of natural resources. Its main feature is to include annual crops and pastures in the same area, with goals to increase profits maintain and or improve the chemical, physical and biological soil properties. The objective of this study was to evaluate the microbiological soil properties and their resilience, as indicators of soil quality in iLP systems, in the Cerrado-Amazon Ecotone of Mato Grosso state. Soil samples were collected in 5 conformations of iLP, a native forest and a succession of crops (soybean/maize) during the rainy season, in two seasons (2012 and 2013). Through univariate analysis, it was observed that the microbiological variables (microbial biomass carbon = MBC; basal respiration; metabolic quotient; activity of the enzymes β-glucosidase, alkaline and acid phosphatase, urease; enumeration of cellulolytic micro-organisms, actinomycetes, bacteria and soil fungi) were influenced by systems and collection times. The second collection time (2013) generally resulted in higher results in microbiological attributes. The highest levels of the MBC were observed in systems with greater diversification and supply of organic matter, as in native forest and iLP A (which from 2005-2009 remained with 3 annual crops and 2009-2011 with Brachiaria brizantha). The systems had modified the activity of enzymes. In which, two systems with iLP resembled the native forest, this in turn, presented a more stable production of enzymes than other systems. Populations of micro-organisms were affected by the systems, but unlike enzymes, the results were higher than in the iLP reference system. In the multivariate analysis, the systems showed results homogeneous and were grouped forming a group in 2012. But there was a segregation of these systems in 2013, where they formed two groups with similar functions on the variables. From one of these groups could be identified that iLP C and iLP A were the systems that most resembled to the native forest, this fact proves that iLP corroborates with the maintenance and/or improvement of the microbiological attributes. Climatic factors had a high influence on the results. The enzyme β-glucosidase showed a strong correlation over other enzymes. The microbiological variables are sensitive to changes in function of land use and time, and are good indicators of soil quality. The collection time influenced the microbiological results. The integrated production system provides resilience in the structure and function of soil microbes. And it is a tool of the least impactful soil management and greater ability to sustainability of soil microbiological component.
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Baretta, Dilmar. « Fauna do solo e outros atributos edáficos como indicadores da qualidade ambiental em áreas com Araucaria angustifolia no Estado de São Paulo ». Universidade de São Paulo, 2007. http://www.teses.usp.br/teses/disponiveis/11/11140/tde-22102007-094221/.
Texte intégralRésumé :
O estudo de indicadores biológicos da qualidade do solo em áreas com araucária é muito importante para entender os processos ecológicos que ocorrem nestes sistemas, já que a fauna edáfica atua na decomposição e mineralização da matéria orgânica e, também, nas propriedades e processos físicos, químicos e biológicos do solo. O objetivo deste estudo foi verificar a possibilidade de utilizar alguns grupos da fauna edáfica e das variáveis ambientais como indicadores da qualidade do solo em áreas com araucária natural e reflorestada, impactadas ou não pela queima acidental, por meio de técnicas de análise multivariada. As áreas estudadas incluem: 1. floresta nativa com araucária (NF); 2. reflorestamento de araucária (R); 3. reflorestamento de araucária submetido a incêndio acidental (RF); e 4. pastagem natural com araucárias nativas e ocorrência de incêndio (NPF). Em cada área, amostras de solo para avaliação da comunidade da fauna edáfica e das variáveis ambientais foram coletadas em 0,3 ha, perto de dez árvores de araucária selecionadas ao acaso, em três épocas contrastantes, usando diferentes métodos de coleta (monólitos e armadilhas). As análises de componentes principais (ACP), canônica discriminante (ACD) e de correlação canônica (ACC) foram aplicadas às variáveis ambientais [carbono da biomassa microbiana (CBM), respiração basal (C-CO2) e quociente metabólico (qCO2), estoques de serapilheira, umidade do solo, pH (CaCl2), matéria orgânica (MO) e teores de P, K, Ca, Mg, H+Al] e atributos da fauna edáfica. Foram encontradas cinco espécies de minhocas (2 famílias), 20 famílias de aranhas e oito famílias de colêmbolos nestas áreas. A diversidade da fauna, CBM, C-CO2, estoques de serapilheira e MO foram sempre superiores na área NF e inferiores na NPF. A comunidade de fauna do solo e as variáveis ambientais apresentaram potencial para serem usadas como indicadores da qualidade do solo. Houve alta correlação canônica entre as variáveis ambientais e a fauna edáfica. Os grupos Collembola, Diplopoda, Chilopoda, Isoptera, Araneae, Oligochaeta, biomassa da macrofauna, índice de diversidade de Shannon (H), estoques de serapilheira, P, CBM e C-CO2 foram responsáveis por praticamente toda a separação entre as áreas, sendo bons indicadores das modificações que ocorrem nos ecossistemas com araucária. A ACD demonstrou que a contribuição de cada atributo para separar as áreas sofreu efeito de sazonalidade. As técnicas de análise multivariada (especialmente ACC e ACD) são importantes ferramentas no estudo de indicadores biológicos de qualidade do solo.The study of biological soil quality indicators in areas with Araucaria is very important to understand ecological processes in these systems, since groups of the soil fauna are major factors in the decomposition and mineralization of organic matter, as well as modifiers of soil physical, chemical and biological properties and processes. The objective of this study was to evaluate the use of soil fauna and environmental variables as quality indicators in natural and reforested Araucaria areas, impacted or not by fire, by means of multivariate analysis techniques. Four study areas included: native forest with Araucaria (NF); Araucaria reforestation (R); Araucaria reforestation submitted to an accidental fire (RF); and native grass pasture with native Araucaria , submitted to an intense accidental fire (NPF). Soil samples containing the soil fauna community and environmental variables were taken in a 0.3 ha area in each area, close to ten Araucaria trees selected at random, in three contrasting seasons, using different collection methods (soil monolith, Pitfall traps). Canonical discriminant analysis (CDA) and canonical correlation analysis (CCA) were applied to the environmental variables [(carbon of the microbial biomass (CMB), basal respiration (C-CO2) and metabolic quotient (qCO2), litter stocks, soil humidity, pH (CaCl2), organic matter (OM), P, K, Ca, Mg, H+Al] and soil fauna attributes. Five earthworm species (two families), 20 spider families and eight springtail families were found in these areas. Soil fauna diversity, CMB, C-CO2, litter stocks and OM were always higher for the NF area and lower for the NPF. The canonical correlation between environmental variables and soil fauna was highly significant. Soil fauna and environmental variables have a great potential as indicators of soil quality. The groups Collembola, Diplopoda, Chilopoda, Isoptera, Araneae, Oligochaeta, biomass of macrofauna, Shannon's diversity index (H), litter stocks, P, CMB and C-CO2 were mostly responsible for the separation between areas, and are therefore good indicators of the changes that occur in the Araucaria ecosystems. CDA identified that the contribution of each attribute for the separation of the areas varied according to the seasonal variation. Multivariate analyses (such as CDA and CCA) are important auxiliary tools in the study of soil quality indicators.
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Otoo, James Nii Aboh. « Suspended Sediment Transport Dynamics and Sediment Yields in Relation to Watershed Characteristics, Upper Green River Basin, Kentucky ». TopSCHOLAR®, 2010. http://digitalcommons.wku.edu/theses/158.
Texte intégralRésumé :
Sediment delivery is a major problem in the Green River, Kentucky, home of 71 of the state’s 103 known mussel species and 151 fish species. The river also provides water for many of its surrounding counties. This research focuses on how suspended sediment loads, grain size, and sediment concentration during runoff events are related to watershed characteristics.
The research characterized suspended sediment loads, grain size, and sediment concentration during runoff events and how they were related to watershed characteristics such as hydro-climatic regime, watershed size, geology and soils, topography and landuse conditions and land cover conditions. The study focused on Brush Creek and Pitman Creek watersheds in the Upper Green River Basin. This research can help in the planning and development of effective environmental strategies by screening out mitigation measures that would not be effective for implementation to minimize sediment load and suspended sediment concentration in the Green River, thereby improving the water quality of the river. Water quality was monitored using data sondes positioned at selected sites in the two watersheds. Water samples were collected during turbidity thresholds of 100 NTU and analyzed for suspended sediment concentrations. Regression models between ‘discharge and stage’ and also between ‘average turbidity and suspended sediment concentration’ were formulated and load estimates were made and compared.
Four sets of samples were collected, two at Brush Creek on 11 April (Brush Creek’s event 1) and 3 May (Brush Creek’s event 2) and the other two at Pitman Creek on the 12 February (Pitman Creek’s event 1) and 3 March (Pitman Creek’s event 2) all in the year 2008. The suspended sediment samples collected for all four events were well graded but had relatively more silt than clay and sand. This could be due to the fact that more time and energy was needed to break the bonds in clay minerals or particles and also to the fact that more energy was also needed to transport sand compared to silt. Brush Creek watershed’s particles had smaller grain sizes than Pitman Creek watershed’s particles. All four events showed clockwise hysteresis indicating that most of the sediments from both watersheds during the events were derived from the bed and banks of the channel or area adjacent to the channel.
The 11 April event (Brush Creek’s event 1) produced an estimated load of 1.1 x 105 kg and a sediment yield of 5.3 x 102 kg/km2. The 3 May event (Brush Creek’s event 2) produced an estimated load of 3.8 x 104 kg and a sediment yield of 1.8 x 102 kg/km2. Brush Creek watershed’s estimated load for the period compared was 4.9 x 105 kg and a sediment yield of 2.3 x 103 kg/km2 (53 kg/km2/day).
The 12 February event (Pitman Creek’s event 1) produced an estimated load of 2.9 x 105 kg and a sediment yield of 8.4 x 102 kg/km2. The 3 March event (Pitman Creek’s event 2) produced an estimated load of 5.7 x 105 kg and a sediment yield of 1.6 x 103 kg/km2. Pitman Creek watershed’s estimated load for the period compared was 1.1 x 106 kg and a sediment yield of 3.1 x 103 kg/km2 (71 kg/km2/day).
Pitman Creek watershed’s higher number of stream network per unit area, its high elevation and relief, its high percentage of erodible soil per unit area, its lesser area of protection of erodible soil by its vegetation compared to Brush Creek watershed’s are responsible for its higher sediment load and yield.
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Fialho, Jamili Silva. « Indicadores da qualidade do solo em Sistemas AgrÃcolas anuais e perenes na Chapada do Apodi - CE ». Universidade Federal do CearÃ, 2005. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=1739.
Texte intégralRésumé :
Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgicoEste trabalho se propÃs a avaliar as alteraÃÃes nas atividades microbiana, quÃmica e fÃsica em solo sob sistemas agrÃcolas anuais e perenes na regiÃo da Chapada do Apodi - CE. Procurou-se testar a hipÃtese de que o uso agrÃcola de Ãreas sob sistemas anuais e perenes causam alteraÃÃes ambientais que influenciam a biomassa e a atividade microbiana do solo, reduzindo-a em relaÃÃo a Ãreas sob vegetaÃÃo natural. Foram selecionadas duas Ãreas com respectivas testemunhas (vegetaÃÃo natural); a primeira sob cultivo de bananeiras (Fazenda Frutacor) e a outra sob cultivo de rotaÃÃo milho e soja (Fazenda Faedo). Coletaram-se amostras compostas de solo em trÃs profundidades (0-5, 5-15 e 15-25 cm) com quatro repetiÃÃes. Nas amostras coletadas foram realizadas anÃlises fÃsicas, quÃmicas e microbiolÃgicas. Fisicamente, observou-se uma elevaÃÃo no teor de argila, com o aumento da profundidade na Ãrea cultivada com banana e na mata natural pivot. Em relaÃÃo aos atributos quÃmicos do solo, os riscos potenciais de salinidade e de saturaÃÃo por sÃdio aparentemente sÃo desprezÃveis. As prÃticas de manejo reduziram o N e o carbono orgÃnico total nos solos das Ãreas sob cultivo. Quanto à microbiologia dos solos, o carbono da biomassa microbiana e a populaÃÃo de fungos micorrÃzicos arbusculares foram mais elevados na profundidade de 0-5cm do solo. A respiraÃÃo basal do solo mostrou que os solos das Ãreas avaliadas tÃm baixa atividade microbiana quando comparados a solos do Cerrado. A atividade e produÃÃo da arilsulfatase e da fosfatase Ãcida foram estimuladas possivelmente, pela competiÃÃo dos Ãnions H2PO4 - e SO4 - pelos mesmos sÃtios de adsorÃÃo nos colÃides do solo, nas Ãreas de banana e rotaÃÃo milho e soja. A maior atividade da enzima β-glucosidase ocorreu nas Ãreas cultivadas, influenciada pela quantidade e qualidade do resÃduo vegetal retornado ao solo.
This work had the proposed to evaluate the alterations in the microbial activities, chemistry and physics in soil under annual and perennial agricultural systems in the area of the Chapada do Apodi - CE. It tried to test the hypothesis that the agricultural use of areas under annual and perennial systems causes environmental alterations that they influence the biomass and the microbial activity of the soil, reducing it in relation to areas under natural vegetation. Two areas were selected with respective witness (natural vegetation); the first under cultivation of banana trees (Fazenda Frutacor) and the other under cultivation of rotation corn and soy (Fazenda Faedo). Samples composed of soil were collected in three depths (0-5, 5-15 and 15-25 cm) with four repetitions. In the collected samples physical analyses, chemistries and microbiological were accomplished. Physically, an elevation was observed in the clay text, with the increase of the depth in the area cultivated with banana and in the forest natural pivot. In relation to the chemical attributes of the soil, the potential risks of salinity and of saturation for sodium seemingly are worthless. The handling practices reduced N and the total organic carbon in the soils of the areas under cultivation. With relationship to the microbiology of the soils, the carbon of the microbial biomass and the population of arbuscular mycorrhizal fungi were more elevated in the depth of 0-5cm of the soil. The basal breathing of the soil identified that the soils of the appraised areas have microbial when compared low activity the soils of the Cerrado. The activity and production of the arylsulphatase and of the acid phosphatase were stimulated possibly, for the competition of the anions H2PO4- and SO4- for the same ranches of adsorption in the coloides of the soil, in the banana areas and rotation corn and soy. The largest activity of the enzyme β-glucosidase happened in the cultivated areas, influenced by the amount and quality of the vegetable residue come back to the soil.
Livres sur le sujet "Biological soil quality"
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Keddy, Cathy. A review of whole organism bioassays for assessing the quality of soil, freshwater sediment, and freshwater in Canada. Ottawa : Environment Canada, Ecosystem Conservation Directorate, Evaluation and Interpretation Branch, 1994.
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1962-, Crane Mark, dir. Derivation and use of environmental quality and human health standards for chemical substances in water and soil. Boca Raton : Taylor & Francis, 2010.
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1962-, Crane Mark, dir. Derivation and use of environmental quality and human health standards for chemical substances in water and soil. Boca Raton : Taylor & Francis, 2010.
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J, Boon P., Howell D. L et Scottish Natural Heritage (Agency : Great Britain), dir. Freshwater quality : Defining the indefinable ? Edinburgh [UK] : The Stationery Office, 1997.
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Stinson, Margaret. Sediment management standards marine bioassays : Task II, recommended quality assurance and quality control deliverables. Olympia, Wash : Washington State Dept. of Ecology, Environmental Investigations and Laboratory Services Program, 1996.
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Programme, United Nations Environment. GEO-6 : Global Environment Outlook : Regional assessment for the Pan-European Region. Nairobi, Kenya : United Nations Environment Programme, 2016.
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Ndiaye, Evelyne L. Winter cover cropping effects on integrative biological indicators of soil quality. 1998.
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Crane, Mark. Derivation and Use of Environmental Quality and Human Health Standards for Chemical Substances in Water and Soil. Taylor & Francis Group, 2010.
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Whitehouse, Paul, Mark Crane, Peter Matthiessen, Graham Merrington et Dawn Stretton Maycock. Derivation and Use of Environmental Quality and Human Health Standards for Chemical Substances in Water and Soil. Taylor & Francis Group, 2009.
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Whitehouse, Paul, Mark Crane, Peter Matthiessen, Graham Merrington et Dawn Stretton Maycock. Derivation and Use of Environmental Quality and Human Health Standards for Chemical Substances in Water and Soil. Taylor & Francis Group, 2019.
Trouver le texte intégralChapitres de livres sur le sujet "Biological soil quality"
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Nelson, Alison G., et Dean Spaner. « Cropping Systems Management, Soil Microbial Communities, and Soil Biological Fertility ». Dans Genetic Engineering, Biofertilisation, Soil Quality and Organic Farming, 217–42. Dordrecht : Springer Netherlands, 2010. http://dx.doi.org/10.1007/978-90-481-8741-6_8.
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Igalavithana, Avanthi Deshani, Sabry M. Shaheen, Jae Nam Park, Sang Soo Lee et Yong Sik Ok. « Potentially Toxic Element Contamination and Its Impact on Soil Biological Quality in Urban Agriculture : A Critical Review ». Dans Soil Biology, 81–101. Cham : Springer International Publishing, 2015. http://dx.doi.org/10.1007/978-3-319-14526-6_4.
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Noor-ul-Ain, Ali Aslam et Fasih Ullah Haider. « Effects of Mulching on Soil Biota and Biological Indicators of Soil Quality ». Dans Mulching in Agroecosystems, 15–40. Singapore : Springer Nature Singapore, 2022. http://dx.doi.org/10.1007/978-981-19-6410-7_2.
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Gorain, Bisweswar, et Srijita Paul. « Biological Indicators for Monitoring Soil Quality under Different Land Use Systems ». Dans Bioremediation Science From Theory to Practice, 121–37. First edition. Boca Raton, FL : CRC Press, [2021] Includes bibliographical references and index. : CRC Press, 2021. http://dx.doi.org/10.1201/9780429327643-8.
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Grifoni, Martina, Gianniantonio Petruzzelli, Meri Barbafieri, Irene Rosellini et Francesca Pedron. « Soil Quality Protection at Heavy Metal-Contaminated Manufactured Gas Plant Sites : Role of Biological Remediation ». Dans Enhancing Cleanup of Environmental Pollutants, 231–60. Cham : Springer International Publishing, 2017. http://dx.doi.org/10.1007/978-3-319-55426-6_11.
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Chinke, N. M., A. C. Odunze, I. Y. Amapu et V. O. Chude. « Long-Term Restorative Farming Effects on Soil Biological Properties for Carbon Stock, Soil Quality, and Yield in a Nigerian Northern Guinea Savanna Alfisols ». Dans Food Security and Safety Volume 2, 403–22. Cham : Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-031-09614-3_18.
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De Haan, F. A. M. « Effects of Agricultural Practices on the Physical, Chemical and Biological Properties of Soils : Part III—Chemical Degradation of Soil as the Result of the Use of Mineral Fertilizers and Pesticides : Aspects of Soil Quality Evaluation ». Dans Scientific Basis for Soil Protection in the European Community, 211–36. Dordrecht : Springer Netherlands, 1987. http://dx.doi.org/10.1007/978-94-009-3451-1_11.
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Cortada, Laura. « Technologies for integrated nematode management in smallholder farming systems : no one-size-fits-all. » Dans Integrated nematode management : state-of-the-art and visions for the future, 457–62. Wallingford : CABI, 2021. http://dx.doi.org/10.1079/9781789247541.0063.
Texte intégralRésumé :
Abstract In this chapter, the need to take a more critical look at the highly precarious and vulnerable situation of smallholder farming systems, the predominant type of the agricultural output worldwide, is emphasized. These farmers represent 98% of the farmers in the world that sustain the local production of staple crops such as rice, maize, cassava, groundnut and millet. Although there is some disparity in the figures, recent data estimates that there are between 380 and 500 million smallholder farming households globally. The productivity of the smallholders' farms depends on soil health and quality, agroecological conditions (irrigated versus rainfed), access to agricultural inputs and new technologies. These last two also critically influence smallholders' ability to manage pests and diseases, including plant parasitic nematodes (PPN). This chapter discusses the epidemiological perspective, diagnostics and surveillance, alternate host and in-field spread of PPN. Breeding programmes for PPN resistance, seed delivery system, importance of clean planting material, influence of land availability to smallholders' ability to practice fallow and rotation for nematode management are described. The use of trap crops, cover crops, nematicides and biological control agents for nematode suppression are also discussed. Future developments aimed at promoting the progress of smallholder farming systems are also mentioned.
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Hale, Robert C., Meredith E. Seeley, Ashley E. King et Lehuan H. Yu. « Analytical Chemistry of Plastic Debris : Sampling, Methods, and Instrumentation ». Dans Microplastic in the Environment : Pattern and Process, 17–67. Cham : Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-78627-4_2.
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AbstractApproaches for the collection and analysis of plastic debris in environmental matrices are rapidly evolving. Such plastics span a continuum of sizes, encompassing large (macro-), medium (micro-, typically defined as particles between 1 μm and 5 mm), and smaller (nano-) plastics. All are of environmental relevance. Particle sizes are dynamic. Large plastics may fragment over time, while smaller particles may agglomerate in the field. The diverse morphologies (fragment, fiber, sphere) and chemical compositions of microplastics further complicate their characterization. Fibers are of growing interest and present particular analytical challenges due to their narrow profiles. Compositional classes of emerging concern include tire wear, paint chips, semisynthetics (e.g., rayon), and bioplastics. Plastics commonly contain chemical additives and fillers, which may alter their toxicological potency, behavior (e.g., buoyancy), or detector response (e.g., yield fluorescence) during analysis. Field sampling methods often focus on >20 μm and even >300 μm sized particles and will thus not capture smaller microplastics (which may be most abundant and bioavailable). Analysis of a limited subgroup (selected polymer types, particle sizes, or shapes) of microplastics, while often operationally necessary, can result in an underestimation of actual sample content. These shortcomings complicate calls for toxicological studies of microplastics to be based on “environmentally relevant concentrations.” Sample matrices of interest include water (including wastewater, ice, snow), sediment (soil, dust, wastewater sludge), air, and biota. Properties of the environment, and of the particles themselves, may concentrate plastic debris in select zones (e.g., gyres, shorelines, polar ice, wastewater sludge). Sampling designs should consider such patchy distributions. Episodic releases due to weather and anthropogenic discharges should also be considered. While water grab samples and sieving are commonplace, novel techniques for microplastic isolation, such as continuous flow centrifugation, show promise. The abundance of nonplastic particulates (e.g., clay, detritus, biological material) in samples interferes with microplastic detection and characterization. Their removal is typically accomplished using a combination of gravity separation and oxidative digestion (including strong bases, peroxide, enzymes); unfortunately, aggressive treatments may damage more labile plastics. Microscope-based infrared or Raman detection is often applied to provide polymer chemistry and morphological data for individual microplastic particles. However, the sheer number of particles in many samples presents logistical hurdles. In response, instruments have been developed that employ detector arrays and rapid scanning lasers. The addition of dyes to stain particulates may facilitate spectroscopic detection of some polymer types. Most researchers provide microplastic data in the form of the abundances of polymer types within particle size, polymer, and morphology classes. Polymer mass data in samples remain rare but are essential to elucidating fate. Rather than characterizing individual particles in samples, solvent extraction (following initial sample prep, such as sediment size class sorting), combined with techniques such as thermoanalysis (e.g., pyrolysis), has been used to generate microplastic mass data. However, this may obviate the acquisition of individual particle morphology and compositional information. Alternatively, some techniques (e.g., electron and atomic force microscopy and matrix-assisted laser desorption mass spectrometry) are adept at providing highly detailed data on the size, morphology, composition, and surface chemistry of select particles. Ultimately, the analyst must select the approach best suited for their study goals. Robust quality control elements are also critical to evaluate the accuracy and precision of the sampling and analysis techniques. Further, improved efforts are required to assess and control possible sample contamination due to the ubiquitous distribution of microplastics, especially in indoor environments where samples are processed.
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Gregorich, E. G., M. R. Carter, J. W. Doran, C. E. Pankhurst et L. M. Dwyer. « Chapter 4 Biological attributes of soil quality ». Dans Soil Quality for Crop Production and Ecosystem Health, 81–113. Elsevier, 1997. http://dx.doi.org/10.1016/s0166-2481(97)80031-1.
Texte intégralActes de conférences sur le sujet "Biological soil quality"
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Liu, Zhichao, Liangmin Gao, Ning Liu et Xiaoxiao Zhang. « A Comparative Analysis of Environmental Quality Assessment Methodsa Case Study of Heavy Metal-Contaminated Soil ». Dans 2015 International Conference on Materials, Environmental and Biological Engineering. Paris, France : Atlantis Press, 2015. http://dx.doi.org/10.2991/mebe-15.2015.114.
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Volkova, S. N., E. E. Sivak et V. V. Gerasimova. « PROPER AGRICULTURAL TECHNOLOGY IS THE KEY TO A HIGH AND HIGH-QUALITY CROP YIELD ». Dans Agrobiotechnology-2021. Publishing house of RGAU - MSHA, 2021. http://dx.doi.org/10.26897/978-5-9675-1855-3-2021-13.
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The article found that the most important feature of proper agricultural technology is its complexity and differentiation depending on local soil-climatic, economic conditions and biological characteristics of cultivated crops.
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Cernat, Sorina, Iulia Nitu et Loredana Beatrice Neagu Frasin. « Research on the Soil-Plant-Fertilizer Interaction in the Main Field Crops ». Dans G.I.D.T.P. 2019 - Globalization, Innovation and Development, Trends and Prospects 2019. LUMEN Publishing, 2022. http://dx.doi.org/10.18662//lumproc/gidtp2022/02.
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In the context of world agriculture, the application of chemical fertilizers remains one of the main ways to increase agricultural production, manage crop quality and improve soil fertility. The application of cultivation technologies, meant to lead to the improvement of agricultural production, determines biological, chemical, physiological changes in the plant and in the soil.
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Kilowasid, Laode Muhammad Harjoni, Wayan Budianto, Hasbullah Syaf, Muhammad Tufaila et La Ode Safuan. « Using of ants and earthworm to modify of soil biological quality and its effect on cocoa seedlings growth ». Dans THE 5TH INTERNATIONAL CONFERENCE ON MATHEMATICS AND NATURAL SCIENCES. AIP Publishing LLC, 2015. http://dx.doi.org/10.1063/1.4930775.
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Chaikovskaya, L. A., V. V. Klyuchenko, M. I. Baranskaya et O. L. Ovsienko. « Influence of microbial preparations and mineral fertilizers on the yield and quality of winter wheat grain ». Dans CURRENT STATE, PROBLEMS AND PROSPECTS OF THE DEVELOPMENT OF AGRARIAN SCIENCE. Federal State Budget Scientific Institution “Research Institute of Agriculture of Crimea”, 2020. http://dx.doi.org/10.33952/2542-0720-2020-5-9-10-116.
Texte intégralRésumé :
The use of biological products based on effective strains of microorganisms with a range of useful properties is one of the aspects of biological farming. The long-term field experiments were conducted in the soil and climatic conditions of the Crimea. А positive effect of the combined use of mineral fertilizers (NPK calculated at P30) and pre-sown inoculation of seeds (biopreparation based on L. nimipressuralis CCM 32-3) on the yield and quality of winter wheat grain was shown. The increase in grain productivity of winter wheat by 31 % compared to control (on average for 3 years) and grain quality indicators: protein and gluten – up to 12.5% and 28.0 % (in the control 9.9% and 19.2%, respectively) was revealed.
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Prikhodko, A. V., I. A. Kameneva, A. I. Yakubovskaya, N. V. Karaeva et M. V. Gritchin. « Influence of green manure phytomass treatment by microbial preparations on grain productivity and quality indicators of winter wheat ». Dans РАЦИОНАЛЬНОЕ ИСПОЛЬЗОВАНИЕ ПРИРОДНЫХ РЕСУРСОВ В АГРОЦЕНОЗАХ. Federal State Budget Scientific Institution “Research Institute of Agriculture of Crimea”, 2020. http://dx.doi.org/10.33952/2542-0720-15.05.2020.23.
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Treatment of the triticale phytomass with the complex biological preparation KBP-5M before incorporation into the soil contributed to the activation of microbiological processes in the 0-30 cm layer. In the variants when the plant was in the phenological stage of spike emergence, we noted an increase in the content of N-NO3 by 0.19-0.46 mg per 100 g of soil; Р2О5 – up to 2.97; K2О – up to mg/100 g. The reason for that was the maximum accumulation of organic matter in the phytomass of triticale at the aforementioned stage of development (8.25-8.52 t/ha). The use of KBP-5M had a positive effect on the development of winter wheat when green manure was the preceding crop. There is a tendency to increase the density of the stalk by 13.3 %, including productive stems – by 3.9 % and the number of grains from 10 plants – by 1.7 % compared to the use of triticale plants as an organic fertilizer without the treatment with biological preparation. Despite the trend of increasing yields from 4.32 to 4.43 t/ha, no reliable yield increase was obtained. When applying KBP-5M on triticale plant residues, there was an increase in protein content by 0.3 % and gluten – by 1.1 % compared to variants without the biological preparation. According to the indicators of 1000-grain weight and hectolitre weight, there were no significant differences between the studied variants. The use of KBP-5M has been justified from an economic point of view since 277 to 1535 rubles per ha of contingent net income was obtained and the payback ratio for the use of the biological product was 1.05–5.79.
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Duma Copcea, Anisoara Claudia, Teodor Mateoc-Sirb, Casiana Mihut, Karel Iaroslav Lato et Nicoleta Mateoc-Sirb. « THE PEDOLOGICAL STUDY OF LANDS IN DUBOVA, MEHEDINTI COUNTY, ROMANIA ». Dans 22nd SGEM International Multidisciplinary Scientific GeoConference 2022. STEF92 Technology, 2022. http://dx.doi.org/10.5593/sgem2022/3.1/s13.40.
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The objective of this paper is the morphological characterization as well as the establishment of soil quality classes in the commune of Dubova, Mehedinti County, Romania. Soil is a primary component for plant production, although it is often considered only as a physical support for plant growth. However, the concerns of mankind over the sustainability of agriculture have made it possible to consider that soil is a living, high-quality system and should, therefore, be preserved. This is the result of several interactions between biological components, including microbial communities, essential for physical-chemical operation. Agricultural crops are threatened by diseases transmitted through the soil, making them difficult to control because of the �hidden� character of pathogens and low efficiency of conventional treatments. These practices greatly affect the quality of the soil, which, in turn, affects the state of crop quality. One of the goals of this paper is to show that, despite the age of the concept of soil quality and the existence of numerous studies, the application of soil quality recommendations would play an important role in crops. However, there is a certain methodology for obtaining soil quality indices that could be suggested in this paper, a methodology based and developed on the basis of previously conducted research in the field. Under current conditions, highlighted by an intensification of globalization processes, sustainable development brings together the main economic and social factors to meet the present needs of mankind without compromising those of future generations.
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Mindy J Spiehs, Bryan L Woodbury, David D Tarkalson, Brian J Wienhold et Roger A Eigenberg. « Long Term Effects of Annual Additions of Animal Manure on Soil Chemical, Physical, and Biological Properties in the Great Plains ». Dans International Symposium on Air Quality and Manure Management for Agriculture Conference Proceedings, 13-16 September 2010, Dallas, Texas. St. Joseph, MI : American Society of Agricultural and Biological Engineers, 2010. http://dx.doi.org/10.13031/2013.32692.
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Wolcott, Caroline C., C. Brannon Andersen et Karen Allen. « ORGANIC CARBON AND NITROGEN CONCENTRATIONS AS INDICATORS OF SOIL QUALITY IN CATTLE FARMS IN THE BELLBIRD BIOLOGICAL CORRIDOR, COSTA RICA ». Dans Joint 69th Annual Southeastern / 55th Annual Northeastern GSA Section Meeting - 2020. Geological Society of America, 2020. http://dx.doi.org/10.1130/abs/2020se-345165.
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Sora, Dorin, et Mădălina Doltu. « GRAFTED TOMATOES – ECOLOGICAL ALTERNATIVE FOR CHEMICAL DISINFECTION OF SOIL ». Dans GEOLINKS International Conference. SAIMA Consult Ltd, 2020. http://dx.doi.org/10.32008/geolinks2020/b1/v2/21.
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This study aimed to identification of an ecological alternative for the chemical disinfection of soil in the greenhouses from Romania. Tomato (Solanum lycopersicum L.) is one of the most popular vegetable crops in the world. The carbohydrate, vitamins, salts of important mineral elements and organic acids content of tomato fruits is very important. Tomato crops are very sensitive to climatic vagaries, so fluctuation in climatic parameters at any phase of growth can affect the yield and the fruit quality. Grafting on Solanaceae is a method which has improved and spread quickly during the past years, a similar approach to crop rotation, a practice meant to increase productivity, resistance or tolerance to biotic and abiotic stress factors and at increasing fruit quality. The research was conducted in a glass greenhouse of the Horting Institute, Bucharest, Romania. The biological material used was a Romanian tomato hybrid (Siriana F1), a Dutch tomato hybrid (Abellus F1) and four rootstocks, a Dutch tomato hybrid (Emperador F1) and three Romanian tomato cultivars (L542, L543 and L544) obtained from the Research and Development Station for Vegetable Growing, Buzău, Romania. The rootstocks have had resistance to biotic stress factors (soil diseases and pests) and the chemical disinfection of soil has was eliminated. The result of this research are presented in this paper.
Rapports d'organisations sur le sujet "Biological soil quality"
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Hoek, J., W. van den Berg, M. Wesselink, W. Sukkel, P. Mäder, E. Bünemann, G. Bongiorno et al. iSQAPER task WP 3.3 soil quality indicators : Influence of soil type and land management on chemical, physical and biological soil parameters assessed visually and analytically. Wageningen : Stichting Wageningen Research, Wageningen Plant Research, Business unit Open Teelten, 2019. http://dx.doi.org/10.18174/472638.
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Shmulevich, Itzhak, Shrini Upadhyaya, Dror Rubinstein, Zvika Asaf et Jeffrey P. Mitchell. Developing Simulation Tool for the Prediction of Cohesive Behavior Agricultural Materials Using Discrete Element Modeling. United States Department of Agriculture, octobre 2011. http://dx.doi.org/10.32747/2011.7697108.bard.
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The underlying similarity between soils, grains, fertilizers, concentrated animal feed, pellets, and mixtures is that they are all granular materials used in agriculture. Modeling such materials is a complex process due to the spatial variability of such media, the origin of the material (natural or biological), the nonlinearity of these materials, the contact phenomenon and flow that occur at the interface zone and between these granular materials, as well as the dynamic effect of the interaction process. The lack of a tool for studying such materials has limited the understanding of the phenomena relevant to them, which in turn has led to energy loss and poor quality products. The objective of this study was to develop a reliable prediction simulation tool for cohesive agricultural particle materials using Discrete Element Modeling (DEM). The specific objectives of this study were (1) to develop and verify a 3D cohesionless agricultural soil-tillage tool interaction model that enables the prediction of displacement and flow in the soil media, as well as forces acting on various tillage tools, using the discrete element method; (2) to develop a micro model for the DEM formulation by creating a cohesive contact model based on liquid bridge forces for various agriculture materials; (3) to extend the model to include both plastic and cohesive behavior of various materials, such as grain and soil structures (e.g., compaction level), textures (e.g., clay, loam, several grains), and moisture contents; (4) to develop a method to obtain the parameters for the cohesion contact model to represent specific materials. A DEM model was developed that can represent both plastic and cohesive behavior of soil. Soil cohesive behavior was achieved by considering tensile force between elements. The developed DEM model well represented the effect of wedge shape on soil behavior and reaction force. Laboratory test results showed that wedge penetration resistance in highly compacted soil was two times greater than that in low compacted soil, whereas DEM simulation with parameters obtained from the test of low compacted soil could not simply be extended to that of high compacted soil. The modified model took into account soil failure strength that could be changed with soil compaction. A three dimensional representation composed of normal displacement, shear failure strength and tensile failure strength was proposed to design mechanical properties between elements. The model based on the liquid bridge theory. An inter particle tension force measurement tool was developed and calibrated A comprehensive study of the parameters of the contact model for the DEM taking into account the cohesive/water-bridge was performed on various agricultural grains using this measurement tool. The modified DEM model was compared and validated against the test results. With the newly developed model and procedure for determination of DEM parameters, we could reproduce the high compacted soil behavior and reaction forces both qualitatively and quantitatively for the soil conditions and wedge shapes used in this study. Moreover, the effect of wedge shape on soil behavior and reaction force was well represented with the same parameters. During the research we made use of the commercial PFC3D to analyze soil tillage implements. An investigation was made of three different head drillers. A comparison of three commonly used soil tillage systems was completed, such as moldboard plow, disc plow and chisel plow. It can be concluded that the soil condition after plowing by the specific implement can be predicted by the DEM model. The chisel plow is the most economic tool for increasing soil porosity. The moldboard is the best tool for soil manipulation. It can be concluded that the discrete element simulation can be used as a reliable engineering tool for soil-implement interaction quantitatively and qualitatively.
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Belkin, Shimshon, Sylvia Daunert et Mona Wells. Whole-Cell Biosensor Panel for Agricultural Endocrine Disruptors. United States Department of Agriculture, décembre 2010. http://dx.doi.org/10.32747/2010.7696542.bard.
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Objectives: The overall objective as defined in the approved proposal was the development of a whole-cell sensor panel for the detection of endocrine disruption activities of agriculturally relevant chemicals. To achieve this goal several specific objectives were outlined: (a) The development of new genetically engineered wholecell sensor strains; (b) the combination of multiple strains into a single sensor panel to effect multiple response modes; (c) development of a computerized algorithm to analyze the panel responses; (d) laboratory testing and calibration; (e) field testing. In the course of the project, mostly due to the change in the US partner, three modifications were introduced to the original objectives: (a) the scope of the project was expanded to include pharmaceuticals (with a focus on antibiotics) in addition to endocrine disrupting chemicals, (b) the computerized algorithm was not fully developed and (c) the field test was not carried out. Background: Chemical agents, such as pesticides applied at inappropriate levels, may compromise water quality or contaminate soils and hence threaten human populations. In recent years, two classes of compounds have been increasingly implicated as emerging risks in agriculturally-related pollution: endocrine disrupting compounds (EDCs) and pharmaceuticals. The latter group may reach the environment by the use of wastewater effluents, whereas many pesticides have been implicated as EDCs. Both groups pose a threat in proportion to their bioavailability, since that which is biounavailable or can be rendered so is a priori not a threat; bioavailability, in turn, is mediated by complex matrices such as soils. Genetically engineered biosensor bacteria hold great promise for sensing bioavailability because the sensor is a live soil- and water-compatible organism with biological response dynamics, and because its response can be genetically “tailored” to report on general toxicity, on bioavailability, and on the presence of specific classes of toxicants. In the present project we have developed a bacterial-based sensor panel incorporating multiple strains of genetically engineered biosensors for the purpose of detecting different types of biological effects. The overall objective as defined in the approved proposal was the development of a whole-cell sensor panel for the detection of endocrine disruption activities of agriculturally relevant chemicals. To achieve this goal several specific objectives were outlined: (a) The development of new genetically engineered wholecell sensor strains; (b) the combination of multiple strains into a single sensor panel to effect multiple response modes; (c) development of a computerized algorithm to analyze the panel responses; (d) laboratory testing and calibration; (e) field testing. In the course of the project, mostly due to the change in the US partner, three modifications were introduced to the original objectives: (a) the scope of the project was expanded to include pharmaceuticals (with a focus on antibiotics) in addition to endocrine disrupting chemicals, (b) the computerized algorithm was not fully developed and (c) the field test was not carried out. Major achievements: (a) construction of innovative bacterial sensor strains for accurate and sensitive detection of agriculturally-relevant pollutants, with a focus on endocrine disrupting compounds (UK and HUJ) and antibiotics (HUJ); (b) optimization of methods for long-term preservation of the reporter bacteria, either by direct deposition on solid surfaces (HUJ) or by the construction of spore-forming Bacillus-based sensors (UK); (c) partial development of a computerized algorithm for the analysis of sensor panel responses. Implications: The sensor panel developed in the course of the project was shown to be applicable for the detection of a broad range of antibiotics and EDCs. Following a suitable development phase, the panel will be ready for testing in an agricultural environment, as an innovative tool for assessing the environmental impacts of EDCs and pharmaceuticals. Furthermore, while the current study relates directly to issues of water quality and soil health, its implications are much broader, with potential uses is risk-based assessment related to the clinical, pharmaceutical, and chemical industries as well as to homeland security.
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Stewart, A. J., G. E. Napolitano et B. E. Sample. Biological quality of soils containing hydrocarbons and efficacy of ecological risk reduction by bioremediation alternatives. Office of Scientific and Technical Information (OSTI), juin 1996. http://dx.doi.org/10.2172/450780.
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Raghothama, Kashchandra G., Avner Silber et Avraham Levy. Biotechnology approaches to enhance phosphorus acquisition of tomato plants. United States Department of Agriculture, janvier 2006. http://dx.doi.org/10.32747/2006.7586546.bard.
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Abstract: Phosphorus is one of the least available macronutrient in the soil. The high affinity phosphate transporters are known to be associated with phosphate acquisition under natural conditions. Due to unique interactions of phosphate with soil particles, up to 80% of the applied phosphates may be fixed forcing the farmers to apply 4 to 5 times the fertilizers necessary for crop production. Efficient uptake and utilization of this essential nutrient is essential for sustainability and profitability of agriculture. Many predictions point to utilization/exhaustion of high quality phosphate rocks within this century. This calls for efforts to improve the ability of plants to acquire and utilize limiting sources of phosphate in the rhizosphere. Two important molecular and biochemical components associated with phosphate efficiency are phosphate transporters and phosphatases. This research project is aimed at defining molecular determinants of phosphate acquisition and utilization in addition to generating phosphate uptake efficient plants. The main objectives of the project were; Creation and analysis of transgenic tomato plants over-expressing phosphatases and transporters Characterization of the recently identified members (LePT3 and LePT4) of the Pi transporter family Generate molecular tools to study genetic responses of plants to Pi deficiency During the project period we have successfully identified and characterized a novel phosphate transporter associated with mycorrhizal symbiosis. The expression of this transporter increases with mycorrhizal symbiosis. A thorough characterization of mutant tomato lacking the expression of this gene revealed the biological significance of LePT3 and another novel gene LePT4. In addition we have isolated and characterized several phosphate starvation induced genes from tomato using a combination of differential and subtractive mRNA hybridization techniques. One of the genes, LePS2 belongs to the family of phospho-protein phosphatase. The functionality of the recombinant protein was determined using synthetic phosphor-peptides. Over expression of this gene in tomato resulted in significant changes in growth, delay in flowering and senescence. It is anticipated that phospho-protein phosphatase may have regulatory role in phosphate deficiency responses of plants. In addition a novel phosphate starvation induced glycerol 3-phosphate permease gene family was also characterized. Two doctoral research students are continuing the characterization and functional analysis of these genes. Over expression of high affinity phosphate transporters in tobacco showed increased phosphate content under hydroponic conditions. There is growing evidence suggesting that high affinity phosphate transporters are crucial for phosphate acquisition even under phosphate sufficiency conditions. This project has helped train several postdoctoral fellows and graduate students. Further analysis of transgenic plants expressing phosphatases and transporters will not only reveal the biological function of the targeted genes but also result in phosphate uptake and utilization efficient plants.
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Fromm, Hillel, Paul Michael Hasegawa et Aaron Fait. Calcium-regulated Transcription Factors Mediating Carbon Metabolism in Response to Drought. United States Department of Agriculture, juin 2013. http://dx.doi.org/10.32747/2013.7699847.bard.
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Original objectives: The long-term goal of the proposed research is to elucidate the transcription factors, genes and metabolic networks involved in carbon metabolism and partitioning in response to water deficit. The proposed research focuses on the GTLcalcium/calmodulinbindingTFs and the gene and metabolic networks modulated by these TFs in Arabidopsis thaliana. The specific objectives are as follows. Objective-1 (USA): Physiological analyses of GTL1 loss- and gain-of-function plants under water sufficient and drought stress conditions Objective 2 (USA / Israel-TAU): Characterizion of GTL target genes and bioinformatic analysis of data to eulcidate gene-network topology. Objective-3 (Israel-TAU): Regulation of GTLmediated transcription by Ca²⁺/calmodulin: mechanism and biological significance. Objective-4 (Israel-BGU): Metabolic networks and carbon partitioning in response to drought. Additional direction: In the course of the project we added another direction, which was reported in the 2nd annual report, to elucidate genes controlling drought avoidance. The TAU team has isolated a few unhydrotropic (hyd) mutants and are in the process of mapping these mutations (of hyd13 and hyd15; see last year's report for a description of these mutants under salt stress) in the Arabidopsis genome by map-based cloning and deep sequencing. For this purpose, each hyd mutant was crossed with a wild type plant of the Landsberg ecotype, and at the F2 stage, 500-700 seedlings showing the unhydrotropic phenotype were collected separately and pooled DNA samples were subkected to the Illumina deep sequencing technology. Bioinformatics were used to identify the exact genomic positions of the mutations (based on a comparison of the genomic sequences of the two Arabidopsis thaliana ecotypes (Columbia and Landsberg). Background: To feed the 9 billion people or more, expected to live on Earth by the mid 21st century, the production of high-quality food must increase substantially. Based on a 2009 Declaration of the World Summit on Food Security, a target of 70% more global food production by the year 2050 was marked, an unprecedented food-production growth rate. Importantly, due to the larger areas of low-yielding land globally, low-yielding environments offer the greatest opportunity for substantial increases in global food production. Nowadays, 70% of the global available water is used by agriculture, and 40% of the world food is produced from irrigated soils. Therefore, much needs to be done towards improving the efficiency of water use by plants, accompanied by increased crop yield production under water-limiting conditions. Major conclusions, solutions and achievements: We established that AtGTL1 (Arabidopsis thaliana GT-2 LIKE1) is a focal determinant in water deficit (drought) signaling and tolerance, and water use efficiency (WUE). The GTL1 transcription factor is an upstream regulator of stomatal development as a transrepressor of AtSDD1, which encodes a subtilisin protease that activates a MAP kinase pathway that negatively regulates stomatal lineage and density. GTL1 binds to the core GT3 cis-element in the SDD1 promoter and transrepresses its expression under water-sufficient conditions. GTL1 loss-of-function mutants have reduced stomatal number and transpiration, and enhanced drought tolerance and WUE. In this case, higher WUE under water sufficient conditions occurs without reduction in absolute biomass accumulation or carbon assimilation, indicating that gtl1-mediated effects on stomatal conductance and transpiration do not substantially affect CO₂ uptake. These results are proof-of-concept that fine-tuned regulation of stomatal density can result in drought tolerance and higher WUE with maintenance of yield stability. Implications: Accomplishments during the IS-4243-09R project provide unique tools for continued discovery research to enhance plant drought tolerance and WUE.