Day 2 :
Keynote Forum
Bodoque J M
University of Castilla-La Mancha, Spain
Keynote: Restoring hydromorphological functionality to improve natural purification capacity of a heavily modified water body
Time : 09:00-09:30
Biography:
Bodoque J M obtained his PhD in Geology from Complutense University of Madrid, Spain. He undertook his Postdoctoral studies at the Department of Civil Engineering, Texas A&M University, USA. Currently, he is a Professor of the Faculty of Environmental Sciences and Biochemistry at the University of Castilla-La Mancha His main research is focused on Hydrology and Geomorphology, which has resulted in more than 40 papers in international peer reviewed journals related to fluvial geomorphology, flood risk assessment and management, soil erosion, water quality and ecological restoration.
Abstract:
We determined the natural purification ability of a floodplain where irrigated agriculture is a dominant and hydraulic connection with the associated river is limited. Denitrification activity was characterized by using different methodological approaches based on i) End-Members Mixing Analysis; ii) characterization of macroinvertebrates of the hyporheic zone; iii) analysis of the denitrification potential; iv) analysis of the bacterial community structure; and v) hydrologic modeling. All the approaches, except EMMA analysis, lead to the same conclusion. Denitrification is almost non-existent because the study site does not have the hydric soil and oxygen-limited conditions needed to enable denitrification. Invertebrates did not show statistically significant differences (P-value higher than 0.05) between the diversity indices corresponding to each of the sampling campaigns. However, significant differences (P-value less than 0.01) were found between the piezometers closest to the river banks and the rest; this may be interpreted because of low hydraulic connectivity. Denitrification potential did not show significant statistical differences (P-value less than 0.01) between the sampling campaigns conducted. This shows that besides the absence of connectivity, irrigation is not able to significantly activate denitrification. Additionally, results from the characterization of the bacterial community structure are consistent with floodplains where denitrification is not effective since most bacterial communities are not linked with NO3. Hydrologic modeling showed that decay change is very low, on the order of 0.01 mgN/L.day, although it would improve around 10% if ordinary floods occur. During the summer months theoretical concentrations of nitrates were lower than expected (e.g. ΔNO3 = - 41 in August 2013), according to the EMMA analysis, which might be due to the intensity of irrigation is spatiotemporally variable in the study site. Our results show that floodplain denitrification has been drastically reduced due to the suppression of flood-pulses. In this context, the creation of riverine wetlands where the hydrological regime is restored would lead to a decay of nitrates whose dynamic evolution increases with flooding, as scenarios tested by hydrological modeling have demonstrated.
Figure 1. Conceptual model implemented.
Keynote Forum
Irena Ymeti
University of Twente, The Netherlands
Keynote: Monitoring the effect of drying-wetting cycles on soil aggregate breakdown using SPECIM hyperspectral camera
Time : 09:30-10:00
Biography:
Irena Ymeti is following the PhD program at the Earth Systems Analysis department at ITC, University of Twente, The Netherlands and working on monitoring soil aggregate breakdown using remote sensing technology. She started to work at the Institute of Geosciences, Energy, Water and Environment at the Polytechnic University of Tirana, Albania building a geo-information (GIS) and RS laboratory for processing and analyzing data for earth science applications.
Abstract:
To monitor soil surface changes, such as aggregate breakdown, it is important to understand the interaction between soil surface and the surrounding environment at high temporal resolution. Within different spatial, temporal and spectral resolution remote sensing (RS) provides continuous data that are suitable for assessment and monitoring of environmental conditions. Using a SPECIM hyperspectral camera under laboratory conditions at a micro-plot scale, we aim to detect and estimate soil aggregate changes over time. We designed an indoor experiment by exposing triplicates of four soils susceptible to detachment (silty loam with various amount of organic matter content and silty loam mixed with hematite) to drying, field capacity and wetting conditions. Twelve soil samples were kept at field capacity for the entire period that the experiment ran. The rest of soil samples were imposed to drying and wetting conditions which were alternated with field capacity condition every three days. All the soil samples were scanned with the SPECIM hyperspectral camera each three days. We collected images data from April to June 2016. When an image has a sufficient high spatial resolution, pixels are smaller than the object so grouping of pixels is possible in order to obtain real-world homogeneous features. Therefore, object-based image analysis (OBIA) is a suitable approach for soil aggregate change detection. However, finding an appropriate method for monitoring soil aggregate breakdown using object-based image analysis for hyperspectral data is required. Moreover, our focus will be on quantifying soil aggregate break down over time using hyperspectral imagery.
Keynote Forum
Emmanuel Mousset
Universite de Lorraine, France
Keynote: Advanced electrochemical treatments for soil remediation
Time : 12:20-13:05
Biography:
Emmanuel Mousset has his expertise in developing advanced electrochemical processes for environmental applications, e.g. soil remediation and wastewater treatment. He got his PhD under supervision of Prof. M A Oturan in the framework of Erasmus mundus ETeCoS3 programme. As tenured CNRS researcher expert in the field, he has been invited in several conferences. He developed the kinetics of primary soil pollutant and the intermediates have been monitored and modeled which allowed predicting the evolution of these molecules. He demonstrated that this kinetics of pollutants degradation depend on the kind of washing agent employed (i.e. its chemical structure) to extract the pollutant from the soil. He also highlighted the ecotoxicity and biodegradability enhancement of the soil washing effluent treated by advanced electrochemical treatment after a certain electrolysis time. From this approach, new scientific and technological insights have emerged and have been patented and awarded.
Abstract:
Statement of the Problem: The remediation of polluted soil and sites is a major of concern not only for the consequence on the ecosystem but also for the contamination of groundwater as resource of drinking water. In this context, many studies have been devoted to find the most cost-efficient solution for soil remediation. Most of the organic pollution is composed of aliphatic hydrocarbons and polycyclic aromatic hydrocarbons (HAPs) but most of them are not biodegradable, which make not efficient enough the biological treatment. Physical techniques only contain the pollution but does not eliminate it while thermal treatment still remain expensive and denature the soil composition. Chemical oxidation methods have been proposed as well, but the addition of oxidants into the soil make the technique uncertain regarding the degradation yield and the hazardous oxidation by-products that can be formed.
Methodology & Theoretical Orientation: Soil washing (SW) and soil flushing (SF) technology using agents to extract and solubilize the pollutants have emerged and have shown promising results. Since these methods only transfer the pollution from soil matrix to liquid matrix, a post-treatment is required. The combination of SW/SF with electrochemical advanced oxidation process (EAOP) have been therefore proposed. EAOP have the advantage to not require the addition of oxidant that are produced continuously and in situ through electrochemical reactions.
Findings: Three major insights emanate from this combination: the surfactant structure has an importance in the pollutant degradation efficiency and the reusability of the washing agent, the integrated process can be performed at neutral pH and without addition of iron source for Fenton reaction, and the biodegradability enhancement with electrolysis time of SW/SF solutions.
Conclusion & Significance: These results gave new possibility of soil remediation by minimizing the use of reagent and by maximizing the pollutants degradation rates and yields.
- Soil fertility
Location: Madrid, Spain
Chair
Bodoque J M
University of Castilla-La Mancha,Spain
Co-Chair
Nataliya P Kirillova
Moscow State University, Russia
Session Introduction
Margarida Arrobas
Polytechnic Institute of Bragança, Portugal
Title: Is the enrichment of organic fertilizers with nitrogen-fixing microorganisms effective in soils ubiquitous in these microbes?
Biography:
Abstract:
Biofertilizers are fertilizing products containing living microorganisms that, when applied to the soil or directly to a seed, colonize the rhizosphere and/or the plant promoting growth by increasing the availability of nutrients. Biofertilizers may improve the bioavailability of nutrients through natural processes such as biological nitrogen fixation, phosphorus solubilization, or through the synthesis of growth promoting substances. Organic fertilizers enriched with heterotrophic free-living nitrogen-fixing microorganisms have recently appeared on the market, seeking to enhance nitrogen fixation by placing the microorganisms directly in the food substrate. However, these nitrogen-fixing microorganisms are ubiquitous in agricultural soils, which allow question of the usefulness of enriching the organic fertilizers in such microbes. Unless the placement of the microorganisms next to the food substrate can give them competitive advantages and increase the biological nitrogen fixation. Field and pot experiments were carried out to compare the performance of two organic fertilizers enriched with free-living nitrogen-fixing microorganisms with other organic and mineral fertilizers. A sequence of horticultural crops (Lettuce-Lettuce-Turnip) was repeated for two years in the same field plots and pots. In the third year, barley was grown without fertilization to assess the residual effect of the fertilizers. Anion exchange membranes were used to monitor nitrate-nitrogen in the soil and plant dry biomass and nitrogen concentration in plant tissues to assess plant nutrient uptake and nitrogen use efficiency. Biofertilizers displayed results lower than mineral fertilizers but higher than organic fertilizers without microorganisms’ addition.
M Angelo Rodrigues
Polytechnic Institute of Bragança, Portugal
Title: Eighteen years of research on soil management systems in rainfed olive groves
Time : 15:05-15:30
Biography:
M Ângelo Rodrigues has obtained his PhD degree in Edaphic and Environmental Sciences at the University of Trás-os-Montes and Alto Douro, Portugal in 2000. He has coordinated and/or participated in two dozen National and International research projects. He has published 130 scientific papers (31 in ISI/JCR journals), book chapters and technical reports. He has been Deputy Director of the School of Agriculture of IPB and President of the scientific committee of the Master’s program of Agroecology at the same institution. He was Vice-Coordinator of the Mountain Research Centre and Vice-Delegate of the Order of Engineers of the district of Bragança, Portugal.
Abstract:
Despite the increased acreage of high-density irrigated orchards, traditional rainfed olive groves maintain huge social importance. While in irrigated orchards cover cropping is generalized, in the rainfed groves the ground continues to be tilled or maintained bare by using herbicides. Cover cropping is important as is an effective mean of reducing soil erosion. However, the covers consume water which can severely reduce olive yields. Over the last 18 years, experimental work has been done in searching for a solution for these orchards. This work summarizes the results obtained in several field trials, which included several soil management treatments, such as conventional tillage, bare soil by using residual or post-emergence herbicides, natural vegetation mowed or grazed, legumes of erect habit grown as green manures and self-reseeding annual pasture legumes. The results indicate that withdrawing tillage and allowing the development of the root system significantly increases olive yield. Cover crops of natural vegetation control soil erosion and improve several soil fertility parameters but significantly reduce olive yield through excessive competition for water. Green manures are difficult to manage since they require be sowing and incorporating into the soil by tillage. If the green manures are managed as mulching it causes significant nitrogen losses to the atmosphere. In these orchards the theoretical model that aggregate the best results is the grown of very early-maturing self-reseeding annual legumes. These plants provide enough protection of the soil, fix nitrogen in rates able to maintain the trees at a nutrition levels higher than the application of 60 kg N ha-1 year-1 and ensures high olive yields due to the little competition for water. These covers proved to be the only way to make profitable organic farming, an interesting alternative for these low input agricultural systems.
- Soil mechanics
Location: Madrid, Spain
Session Introduction
Kamel Bezih
Mostefa Ben Boulaid University, Algeria
Title: Deterministic and reliability analysis of RC bridges including soil-structure interaction
Time : 10:25-10:50
Biography:
Kamel Bezih has graduated with a Master research and specialization in mechanical of soil and rock, from Pierre and Marie Curie University (Paris 6), France in 2002. In addition, a Magister degree in Civil Engineering, from University of Batna, Algeria in 2004, and PhD degree in Structure and Geomaterials from Mostefa Ben Boulaid University (Batna 2), Algeria in 2017. His research interests include numerical modeling of structure, geotechnical modeling tools, the mechanical behavior of soil, sol-structure interaction and the evaluation of the reliability of structures in Civil Engineering. He has also participated in several national and international conferences.
Abstract:
The objective of the present research is to show and to quantify the importance of soil parameter uncertainties on the redistribution of internal forces in RC bridges, as well as their effect on the safety assessment of these structures. In this paper, a reliability-mechanical approach was developed to study the effect of soil-structure interaction for RC bridges. The modeling of soil-structure interaction is incorporated in the mechanical model of RC continuous beam, by considering nonlinear elastic supports. The deterministic and reliability analysis allows us to evaluate the safety of the RC bridge regarding the soil parameter uncertainties. The numerical analysis allows us to evaluate the safety of the RC bridge regarding the soil parameter uncertainties. Furthermore, the obtained results indicate that soil–structure interaction effects and uncertainty of soil parameters should be considered in the reliability assessment of RC structures. This analysis can have significant impact on the design rules of redundant RC structures, especially when large soil uncertainties are involved.
Shaqour F
University of Jordan, Jordan
Title: Shear strength of naturally cemented calcrete soil compared to artificially cemented and un-cemented sand
Time : 11:30-11:55
Biography:
Shaqour F has completed his PhD in Engineering Geology from Leeds University of UK. He has many years of experience in teaching undergraduate and post graduate students in Australian Universities and overseas with proven research track record and management of research and engineering projects. He has published high standard research articles in reputed international journals. Currently his research is on improvement of clay soils using cement dust, lime and geopolymerization. He has strong technical background on Engineering Geology, Hydrogeology, Engineering Materials and, with excellent written and oral communication skills. He has reviewed many articles to the Journal of Engineering Geology and other journals on various geotechnical aspects including soft soils and clays.
Abstract:
Statement of the problem: Cemented calcrete soil is commonly present in semi-arid areas and can form a good construction material as road bases, however wetting can cause distress problems. Such a calcrete deposit is available in North Jordan and has not been characterized for angle of internal friction and cohesion under dry and wet conditions.
Methodology & Theoretical Orientation: Direct shear tests were carried out on naturally cemented calcrete soil and artificially cemented sand following multi stage test procedure to determine their angle of internal friction and cohesion. Both undisturbed and reconstituted samples of the calcrete soil have been tested. Un-cemented sand is also tested to obtain reference strength parameters for comparison purposes. Each sample was sheared until failure, at an initial normal load which then increased incrementally for three additional stages.
Findings: The first peaks of the multistage testing on naturally cemented calcrete soil showed a friction angle between 31o and 63o and cohesion between 10 to 150 KPa, while artificially cemented sand gave values between 32o and 70o and cohesion ranging from 7 kPa to 200 kPa. Later peaks of artificially cemented sand and naturally cemented calcrete soil gave angle of internal friction of 35o, like those of un-cemented sand and reconstituted calcrete due to the breakdown of the bonding after the first stage of shearing.
Conclusion & Significance: The naturally cemented calcrete proved to possess high shear strength that makes them good foundation soils and suitable as road bases; however, they lose a considerable percentage of their strength upon reworking and wetting. Recommendations are made to determine the compaction characteristics and consider the influence of wetting on the shear strength of calcrete deposit.
Erik R Christensen
University of Wisconsin–Milwaukee, USA
Title: Trace element data for surface soil and moss in Norway analyzed by PMF and PCA with optional CLR transformation
Time : 14:15-14:40
Biography:
Erik R Christensen is a distinguished Professor Emeritus of Environmental Engineering. He has edited a book on contaminated aquatic sediments and co-authored the book Physical and Chemical Processes in the Aquatic Environment (Wiley, 2014) with An Li. He has been an Associate Editor for the Journal of Great Lakes Research and the ASCE Journal of Environmental Engineering, and published over 90 peer reviewed journal articles. He is a fellow of the American Society of Civil Engineers.
Abstract:
Statement of the Problem: Classical principal component analysis (PCA) is useful to separate anthropogenic and geogenic sources of trace elements in surface soil and moss. However, while mass input (µg/g) of trace elements can be determined by positive matrix factorization (PMF), this cannot readily be done by PCA. Also, classical PCA can be sensitive to minor changes in input data. We considered here datasets for 464 stations in mainland Norway and more than 21 trace elements including Pb, Cd, Ag, As, and Hg and several rare earth elements. PMF scores for individual stations were plotted, and PCA with CLR transformation was tested to check robustness and to see if significant factors were missed.
Methodology & Theoretical Orientation: Surface soil and moss (Hylocomium splendens) samples were collected all over mainland Norway from open air sites. Chemical and statistical analyses were conducted as described previously.
Findings: PMF factor contributions (scores) of anthropogenic factors from dated moss samples with high levels of Pb, Cd, Cr, Co, As, Hg at Svanvik near the Russian border confirm the influence of a Russian copper - nickel smelter. A much smaller increase is seen in the soil samples. Using CLR transformation with PCA, increased robustness is reflected by the fact that all five factors each have near-equivalent PMF factors, which is not the case for PCA without CLR transformation. However, scores are noisy and have significant negatives. Classical PCA on soil samples produces an Ag, Hg factor at Ulefoss, along with a distinct Eu factor free of Ag and Hg (PC5), both not seen with the CLR transformation.
Conclusion & Significance: PMF and PCA factor scores at individual stations such as Svanvik or Ulefoss can be an important adjunct to score maps in identifying pollution sources and PCA with CLR transformation provide more robust factors, however, at the possible expense of missing significant and more distinct factors.
- Soil Microbiology
Location: Madrid, Spain
Session Introduction
Hui-zhen Qiu
Gansu Agricultural University, China
Title: Effects of continuous potato monoculture on microbial community diversities and taxa abundances in potato rhizosphere soil
Time : 11:05-11:30
Biography:
Hui-Zhen Qiu has her expertise in teaching and scientific research in the field of Plant Nutrition and Fertilization for more than thirty-five years in Gansu Agricultural University. She has focused her research work both in nutrition regulation of potato and rhizosphere processes and management of continuous potato monoculture in the past ten years. She and her group have revealed the mechanisms of the obstacles from continuous potato monoculture, and have established a set of technologies for managing rhizosphere microbiome to improve potato plant health and productivity, based on organic fertilizer and PGPRs.
Abstract:
Continuous potato monoculture has been a big problem in potato production in Gansu Province, west China. Long term field experiments were carried out to reveal the mechanism of obstacles from continuous potato monoculture. Soils along a seven-year gradient of potato monoculture were collected and microbial communities and populations were characterized using the approaches of PCR-DGGE, and high throughput pyrosequencing approaches. The principal findings are as follows: the diversity (HShannon) and richness (SChao1) indices of bacterial community were linearly decreased over time and corresponded to a decline of potato tuber yield decline and the disease incidence increase. Second, soil bacterial and fungal communities exhibited differential responses to the potato monoculture, the overall soil bacterial communities were shaped by potato monoculture, Acidobacteria and Nitrospirae were linearly decreased over time in abundance. Fusarium sambucim, Fusarium solani, and Rhizoctonia solani the major soil-borne pathogen-associated fungal genus substantially detected were linearly increased over time in abundance. Molecular ecological network analysis tool was used to study the interactions and network organizations of fungal communities in yield-invigorating (healthy,1-3 years’ continuous potato monoculture) and -debilitating (diseased, 4-7 years’) soils induced by prolonged potato monoculture, based on the relative abundances of internal transcribed spacer sequences derived using pyrosequencing. The results shown that the healthy network had more number of functionally interrelated operational taxonomic units (OTUs) than the diseased one; healthy network contained 6 (4%) generalist OTUs whereas the diseased contained only 1 (0.6%) marginal generalist OTU; and majority (55%) of OTUs in healthy soils were stimulated by a certain set of soil variables but the majorities (63%) in diseased soils were inhibited(Fig.2), which suggested that a healthy community was a better organized or a better operated community than the diseased one; a healthy soil was a soil with variables that encouraged majority of fungi whereas a diseased soil discouraged.
- Agronomy
Location: Madrid, Spain
Session Introduction
M Angelo Rodrigues
Polytechnic Institute of Bragança, Portugal
Title: Cover cropping in rainfed olive orchards
Time : 11:55-12:20
Biography:
M Ângelo Rodrigues has obtained his PhD degree in Edaphic and Environmental Sciences at the University of Trás-os-Montes and Alto Douro, Portugal in 2000. He has coordinated and/or participated in two dozen National and International research projects. He has published 130 scientific papers (31 in ISI/JCR journals), book chapters and technical reports. He has been Deputy Director of the School of Agriculture of IPB and President of the scientific committee of the Master’s program of Agroecology at the same institution. He was Vice-Coordinator of the Mountain Research Centre and Vice-Delegate of the Order of Engineers of the district of Bragança, Portugal.
Abstract:
Cover cropping has been advocated as a mean of reducing soil erosion and increasing soil organic matter and functional biodiversity. There are many other good reasons to establish a cover crop in an orchard since it can improve in several ways the physical, chemical and biological properties of a soil. However, herbaceous vegetation competes for resources. In intensive-managed orchards, without limitation of available water and nutrients, probably this is a minor problem. In rainfed orchards, to balance the potential beneficial effects of cover crops and their strong competition for resources in particular for available water is a great challenge. In this work, we report results from field trials from which we are proposing a model of intervention in rainfed managed orchards consisting of the use of very early maturing self-reseeding annual legumes as a cover crop. These plants are able to enrich the soil with nitrogen and to protect the soil all year round through a green cover of vegetation during autumn-spring and a mulch of dead material during summer. Experimental results also showed that nitrogen nutritional status of the olive trees and olive yields increased in comparison to a plot of natural vegetation fertilized with 60 kg N ha-1 yr-1.
- Soil Management
Location: Madrid, Spain
Session Introduction
Victor Scartezini Terra
University of Rio Verde, Brazil
Title: Development of a coupled model for air and water flow through unsaturated soils: Simulation of an axis-translation technique procedure
Biography:
Victor Scartezini Terra has completed his Master’s degree from Federal University of Goias. she is an Adjunct Professor at University of Rio Verde.
Abstract:
Flow problems in unsaturated soil mechanics can be laid in several engineering problems, such as transient analysis of slope stability, volume change in collapsible and expansive soils, earth dam projects, among others. To simulate these problems, plenty of partial differential equations (PDEs) simulating water and air flow through soils can be found on the literature, such as the equations developed by Fredlund and Gitirana Jr (2005) and Ba-Te (2004). This paper aims to develop a formulation based on PDEs governing the coupled flow of water and air phase through unsaturated soils. The equations obtained here are implemented in a PDE solver named FlexPDE, version 6 (PDE Solutions, 2007). To verify the developed FlexPDE model, a benchmark analysis is made by comparing the results from FlexPDE with the results obtained with the package AIR/W from the GeoStudio software (GEO-SLOPE International, 2012). The benchmark analysis consists of a simulation of the axis-translation technique for determination of the matric suction in unsaturated soil. A one-dimensional analysis is made considering a cylindrical soil sample with 2 cm of high. Then the axis-translation technique is simulated by applying a controlled air pressure on the top of the domain. Between the several constitutive relation models that can be found in the literature, the equations of van Genuchten (1980) and Mualem (1976) for the soil-water characteristic curve and for the permeability equations were adopted in this paper. The results show that the FlexPDE model works well in the simulation of the coupled flow of air and water phase through the unsaturated soil. An observation is made related to some problems founded on the AIR/W package in transient analysis with very low timesteps.
- Edaphology
Location: Madrid, Spain
Session Introduction
Rodriguez-Buenfil I M
CIATEJ, Mexico
Title: Characterization of three types of soils from Yucatan Mexico and evaluation of their effect on the growth of habanero chili plants
Time : 14:40-15:05
Biography:
Ingrid Rodríguez-Buenfil has her expertise in Biotechnological Process and Design of experiments. She has thirty years of experience in scientific research, with participation in 76 projects (27 as Project Manager), three patents granted and seven patent applications in process. 122 publications among scientific articles, extensive memoirs, book chapters and books among others. Thirty-two graduate students. She was a Founding Director of the Southeast Unit of Center for Research and Assistance in Technology and Design of the State of Jalisco (CIATEJ) in Mérida Yucatán, from July 2002 to April 2015. Her current project is Analysis of the metabolomics changes during the development of the fruit Capsicum chinense jacq. cultivated in different soil types (Project CONACYT 257588).
Abstract:
Statement of the Problem: The fruits of Capsicum chinense plants grown in the Yucatan Peninsula have its appellation of origin based on their unique characteristics, which are suggested to be due to the particularities of the soils in they are cultivated. Leptosols are the most common soils in the world (12%). This is also the case in Mexico (24%) and in the state of Yucatán (80%) The high spatial heterogeneity of Leptosol areas complicates agricultural development and transfer of agricultural technology, among other things. The aim of this study was to characterize three types of soil from Yucatan México (K’áankab lu’um, Red, Box lu’um, black and stony ch’ich’ lu’um, brown) and to analyze its effect on the growth habanero chili plants.
Methodology: A greenhouse cultivation of 120 plants (40 per land type) was established, after one month were measured: height, number of leaves, number of buttons and flowers. The nutrients determination was performed following the methodology described in Official Mexican Standard NOM-021-SEMARNAT-2000.
Findings: The black soil was the one with the highest content of phosphorus (P) and carbon (C) and the red the lowest in the initial soil, while in the soil after one month of plant growth, red had the highest phosphorus content with significant differences between them. The height of the plants and the number of buttons was greater in those that were grew in red soil whereas for the number of flowers and leaves there was no significant differences.
Conclusion & Significance: The nutrient content in soils suggests that they are in acceptable concentrations for the development of the plant, however the values of EC and CIC suggest possible problems of availability of these nutrients to the plant. The red soil was the best for the height of the plants and the number of buttons.
Figure 1. Nutrient content in different soil types
- Soil Pollution
Location: Madrid, Spain
Session Introduction
Tania Pardo
IIAG-CSIC, Spain
Title: Assessment of the use of bacterial inoculants for improving the agromining potential of Ni-hyperaccumulating plant species at field-scale
Time : 15:55-16:20
Biography:
Tania Pardo is a young researcher and specialized in the remediation of trace element-contaminated soils through phytotechnologies. She obtained her PhD degree in 2013. Her main research activities have been focused on the study of the suitability of different organic composts, pig slurry, digestate, biochar and inorganic (Fe oxides, nano-oxides, lime, red mud derivatives, etc.) amendments, and selection of plants species, for the phytoremediation of trace element-contaminated soils. Particular emphasis has been on the study of the treatments effects on the availability and speciation of trace elements in soil; the uptake and translocation of these elements in plant, and; the soil quality and associated environmental risks. Currently, her research is focused on the optimization of cropping systems of Mediterranean Ni-hyperaccumulating plant species to produce Ni-rich biomass for phytomining purposes, and the combined use of soil amendments and microbial inoculants for the phytoremediation of Cu contaminated mine soils.
Abstract:
The synergistic activity between plants and microorganisms may contribute to the implementation of soil management strategies in natural metal-enriched soils. Inoculation of plants with plant growth-promoting bacteria (PGPB) can induce beneficial effects on plant growth, health and resistance to stress, as well as increasing nutrient availability and changing metal solubility in soil. The present study aimed to assess the potential use of PGPB for improving the establishment and yield of the Ni-hyperaccumulating Mediterranean species Alyssum murale for agromining purposes at field scale. Experimental plots of 4 m2 were established in an ultramafic outcrop of Santiso (NW Spain) and seedlings of previously inoculated two-month-old A. murale were transplanted (4 plants m-2) in three replicate plots. The inoculation treatments included: (i) non-inoculated plants (NI); (ii) Arthrobacter sp. strain LA44; (iii) Arthrobacter sp. strain SBA82; and (iv) Variovorax paradoxus strain AB30 all originally isolated from rhizosphere of Ni hyperaccumulating plant species). After four months, soil pH and extractable-Ni concentrations were not modified by plants, but inoculated plants (especially LA44 and SBA82 strains) increased the soil CEC and water-soluble organic C content. The composition of soil bacterial communities of LA44- and SBA82-soils was like that of untreated soils, but the structure of AB30-soils was different to other soils. LA44 and SBA82 strains increased plant coverage and reduced the levels of some antioxidant enzymes activities compared to NI-plants (CAT and SOD). LA44 strain also enhanced aerial-biomass production of A. murale, obtaining a productivity 5-fold higher than NI-plants. All plants had similar Ni concentrations in their shoots (3.7-4.1 g kg-1), however the phytoextracted Ni per plant and Ni yield was significantly increased by LA44 and SBA82 strains. Therefore, the inoculation of A. murale with LA44 and SBA82 strains improved the agromining success without modifying the structure of soil bacterial communities, and shows the potential of PGPBs in agromining systems.
Figure 1. Aerial biomass production and Ni yield of A. murale after four months of growth at field.