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The study was under taken to assess the fertility status of the flood plain soils of some selected local government areas of Kebbi State and recommend management practices to be provided for the maximum yield of tomatoes in Kebbi State. Soil samples were analyzed for the various physical and chemical properties following the standard procedures. The study revealed that the soils were predominantly sandy loam in texture with the mean particles composition of 715.71 gkg-1, 87.42 kg-1 and 196.87 kg-1 for sand, silt and clay, respectively. The soils contained low organic carbon of 6.0 gkg-1 and high concentration of nitrogen (0.8 gkg-1) which might be due to frequent addition of nitrogenous fertilizers on the soil. The low available phosphorus of 0.64 mgkg-1 was observed which might be due to acidity level of the soils (pH 5.6). On the basis of exchangeable bases, the soils were discovered to be low in Ca (1.51cmolkg-1), but high in Mg content (1.78 cmolkg-1). The soils contained high Na value of 0.59cmolkg-1 an indication ofsodicity hazard. The K content of 0.64 cmolkg-1 was also high in the soils of the study area. Based on the obtained values of the above parameters, the soils could be considered as medium in fertility. Based on the concentration of EC (0.55 dsm-1) ESP (6.04%) and pH 5.6, the soils could be considered to be free from salinity and sodicity at least for now, but has

Floodplain soils are the sites for most of agricultural activities during dry seasons. With efficient irrigation facilities such as tube wells and water pumps, they can produce 2-3 short duration crops during a year. However, due to persistent irrigation activities, these soils are always susceptible to salinization and sodicity hazards. High salt content in the soil inhibits uptake of plant nutrients and water, while high sodium content in sodic soils destroys soil structure and consequently reduces the rate of permeability and aeration. In view of this, it becomes necessary to assess the level of salinity and sodicity of the floodplain soils of the study area; Augie, Argungu, Birnin Kebbi and Bunza Local Government Area of Kebbi State, so as to ascertain the appropriate management practices to be applied on these soils. Soluble salts were as such analyzed. It was observed that the calcium (Ca2+), magnesium (Mg2+), potassium (K+) and Sodium (Na2+), were in the value of 1.90cmol(+)kg-1, 1.66cmol(+)kg-1, 0.16cmol(+)kg-1, and 0.34cmol(+)kg-1, respectively. Salinity and sodicity determinants were also analyzed where pH was observed to be 6.88, electrical conductivity (EC) 0.19dSm-1 exchangeable sodium percentage (ESP) 2.09%. The data were subjected to statistical analysis so as understand the relationship between the four local government areas. Based on the concentration of pH, EC and ESP, the soils could be said to be free from salinity and sodicity hazards at least for now. However, due to the high concentration of Mg2+, K+ and Na+, the soils could be said to have potential threat to salinity and sodicity problems and therefore proper management strategies should be practiced to prevent their further concentration.

A study on quantifying the productivity of Wukari flood plain soils using Neill’s Productivity Index (PI), Modified Neill’s Productivity Index (PIm) and Riquier Productivity Index (RI) was carried out. The applicability and validity of the productivity index models were determined using rice as a test crop. Result showed significant relationships with coefficients of determination (R2) of 0.7158, 0.7204 and 0.8778 found between grain yield of rice (Y) and PI, PIm and RI values respectively. The highest and the lowest grain yield of rice to a reasonable extent correspond to the higher and the lower productivity index values, respectively. Higher productivity indices explained higher mean grain yield of rice. The productivity indices values decreased with the decrease in grain yield. The grain yield of grain followed productivity index predictions and are hereby recommended as tools of soil productivity assessment in the study area.

The aim of this study was to examine the effects of seasonal flooding on the properties of floodplain soils of Wukari Area of Taraba state. The treatments consisted of five different locations of Gidan-Idi, Gindin-Dorowa, Tsokundi, Rafin-Kada and Nwuko and three different soil sample depths of 0-20 cm, 20-40 cm, and 40-60 cm laid out in a completely randomized design (CRD) and replicated three times. Soil samples were collected from each plot in 2016 and 2017. All soil samples were analyzed for physical and chemical properties. The results obtained were subjected to analysis of variance and means separated using F-LSD test at p≤.05. The results of the soil properties analysis showed that some of the determined parameters were significantly different at the different sample locations at p≤.05. The soils of Wukari Floodplains are mostly clay loam in texture having very slightly acid to neutral soil reaction, moderate organic matter, low total N, moderate available P, low exchangeable bases and CEC. The flood plain soils were moderate in soil fertility, a confirmation of the general characteristic of Savanna soils. The soils were not deficient in micronutrients. Seasonal flooding had significant (positive) influence on some physical and chemical properties of the flood plains most particularly at Rafin-Kada.

The concentrations of 28 polychlorinated biphenyls (PCBs) were determined in soils collected at three depths from thirteen different sites along the floodplain of the lower reaches of the River Niger (LRRN) in Nigeria. The aim of the study was to provide data on the levels of contamination, sources of the contaminants, and risks to the ecosystem and humans. Soil samples were Soxhlet extracted with a solvent mixture of dichloromethane (DCM)/n-hexane and cleaned up on a column packed with Florisil and silica gel. The PCBs in the samples were quantified by gas chromatography-mass spectrometry. The Ʃ28 PCB concentrations in the floodplain soils varied between not detected (nd) and 11,151 ng g−1 for different sampling sites and depths. The PCB concentrations and homologue distribution patterns in soil profiles of the floodplain of the LRRN showed remarkable differences with respect to sites and depths. The results obtained were used to evaluate the ecological and human health risks, which indicated that there is a potential risk to organisms and humans from exposure to PCBs in these soil profiles. The source evaluation as determined by principal component analysis suggested that PCBs in these soil profiles came from burnt circuit boards, cable wires, use of paints, discharges from transformers, long-range migration, and deposition.

Nitrate pollution in aquatic ecosystems is still a major problem in Germany. There is a great potential to permanently remove nitrate from aquatic systems through denitrification as a relevant ecosystem function. However, the controlling factors and the dimension of the denitrification potential are still not fully understood due to the high complexity of the process. This study presents the combined assessment of potential soil denitrification rates, physical and chemical soil parameters, and hydrological parameters from six floodplains of four large German rivers, namely the Rhine, the Elbe, the Weser, and the Main. Based on multivariate statistics, results show that the denitrification potential of soil was almost solely controlled by soil pH. The lab assays showed mean soil denitrification potentials of 6.4–11.4 mg N m−2 h−1 (pH < 7) and 23.0–30.5 mg N m−2 h−1 (pH > 7). We contend that when upscaling these estimates to annual rates of potential denitrification, the duration of average inundation should be incorporated, as this accounts for water saturation and nutrient supply − the major controlling variables for denitrification. Results provide evidence that the denitrification potential can only be fully exploited in frequently inundated floodplains. Thus, despite favorable soil conditions for denitrification, floodplains that have suffered from anthropogenic impacts, lose their importance in nitrate removal for the river system. We conclude that pH and lateral hydrological connectivity are likely to be key factors that should be considered when estimating denitrification as an ecosystem function.

An experiment was replicated simultaneously at two sites of floodplain soils of Bangladesh to find out the optimum application rate of zinc and boron fertilizers for crops under cauliflower-maize-transplant aus rice pattern. Randomized complete block design with three replications was used in the experimentation. The first crop of the pattern received four zinc levels (0, 2.0, 4.0, and 6.0 kg ha−1), and three boron levels (0, 1.5, and 3.0 kg ha−1). In second crop, two additional treatments receiving 2.0 kg Zn ha−1 and 2.0 kg Zn ha−1 + 1.5 B ha−1 were added; in the third crop, another four treatments were added by further application of 2 kg Zn ha−1 in each. Other nutrients viz. N, P, K, and S were used equally at recommended rates for all plots. In such a 3-crop pattern, application of 4.0 kg Zn ha−1 and 1.5 kg B ha−1 at a time to the first crop or 2.0 kg Zn ha−1 to each of the first two crops along with 1.5 kg B ha−1 to the first crop was sufficient to achieve satisfactory yield of the crops. Con...

Large rivers and their deltaic parts and adjacent coastal zones are subjected to strong anthropogenic influence and are often considered as hotspots of environmental pollution. The Don River basin is a highly urbanized area with developed agriculture and industry which negatively affect water quality, aquatic ecosystems and soils. The main objectives of the proposed research were to determine the levels of potentially toxic elements (PHEs) in soils of various aquatic landscapes of the study area, as well as to reveal the relationships between the content of exchangeable PTEs and the physical-chemical properties of floodplain soils.Depending on the soil-landscape and hydrological conditions and taking into account the intensity of anthropogenic influence, the following zones were identified: the lower Don floodplain from the Tsimlyansk Reservoir to the source of the Mertvy Donets River, Don Delta, the coastal zone of the Taganrog Bay, the mouths of small rivers flowing into the bay, and Taganrog city, an industrial port center on the northern coast of the bay.The floodplain and coastal landscapes of the study area are dominated by Fluvisols. Solonchaks, Arenosols and Haplic Chernozems which are background soils of the region are less common. Soil samples were collected in summer 2020 from the surface soil horizon (0–20 cm deep). The particle size analysis was conducted using the pipette method; the total organic carbon content in the soils was determined using the dichromate oxidation; the pH was measured by potentiometry in the supernatant suspension of soil and water in a ratio of 1:2.5. The total concentrations of Cr, Mn, Ni, Cu, Zn, Cd, and Pb were determined by X-ray fluorescence analysis using a Spectroscan MAX-GV spectrometer (Spectron, Russia), and the content of exchangeable forms extracted from the soil by NH4Ac buffer solution with pH 4.8 and soil/solution ratio of 1:10 for 18 h was determined by atomic absorption spectrophotometry.The obtained results showed that soils of the Lower Don and Taganrog Bay coastal zone are rather contrasted in terms of properties and metal contents, which indicates the variability of landscapes, natural and anthropogenic processes in the studied systems. High CV values for Pb, Zn, Cd and Cr indirectly indicate strong anthropogenic influence on these environments. The results of PCA analysis showed that there are two association of metals in terms of geochemical behaviour and sources. The first one included Cr-Zn-Pb-Cd, the elements of anthropogenic origin, the second Mn, Ni, and Cu, which are probably of mixed origin. The obtained results showed that the coastal zone is a diverse and complex system subjected to anthropogenic activities, which is pronounced in the enrichment of aquatic soils with a number of metals and higher proportions of exchangeable forms from different types of sources.This work was funded by the Russian Science Foundation, grant no. 20-14-00317.

The pollution of floodplain, deltaic and adjacent coastal soils in large fluvial systems, considered an urgent environmental problem, as well as potentially toxic elements in such environments, can negatively affect aquatic ecosystems, as well as pose significant risks to human health. This paper is devoted to the geochemistry of potentially toxic elements in soils of the Lower Don basin, which is one of the largest and most anthropogenically transformed water bodies in Southern Russia, as well as the adjacent areas of the Taganrog Bay coast. The median element concentrations in the soils of the study area were consistent with the world soil average and the contents of elements in background soils. Comparative assessment of the spatial distributions as well as the results of Pearson’s correlations, cluster analysis and principal component analysis showed that Cr, Ni, Cu and Zn are predominantly of natural origin; Mn and As are of mixed sources; and Cd and Pb are predominantly of anthropogenic origin. The geochemical anomalies of elements were associated with the impact of local anthropogenic sources. Geochemical background values for Cr, Mn, Ni, Cu, Zn, As, Cd and Pb in the soils of the Lower Don and the Taganrog Bay coast determined using the ‘median + 2 median absolute deviations’ approach are presented. The highest values of the integrated pollution indices were observed in floodplain soils of small rivers.

The frequency and duration of flooding events are increasing due to land-use changes increasing run-off of precipitation, and climate change causing more intense rainfall events. Floodplain soils situated downstream of urban or industrial catchments, which were traditionally considered a sink of potentially toxic elements (PTEs) arriving from the river reach, may now become a source of legacy pollution to the surrounding environment if PTEs are mobilised by unprecedented flooding events.\ud \ud When a soil floods, the mobility of PTEs can increase or decrease due to the net effect of five key processes; (i) the soil redox potential decreases which can directly alter the speciation, and hence mobility, of redox sensitive PTEs (e.g. Cr, As), (ii) pH increases which usually decreases the mobility of metal cations (e.g. Cd2+, Cu2+, Ni2+, Pb2+, Zn2+), (iii) dissolved organic matter (DOM) increases, which chelates and mobilises PTEs, (iv) Fe and Mn hydroxides undergo reductive dissolution, releasing adsorbed and co-precipitated PTEs, and (v) sulphate is reduced and PTEs are immobilised due to precipitation of metal sulphides. These factors may be independent mechanisms, but they interact with one another to affect the mobility of PTEs, meaning the effect of flooding on PTE mobility is not easy to predict. Many of the processes involved in mobilising PTEs are microbially mediated, temperature dependent and the kinetics are poorly understood.\ud \ud Soil mineralogy and texture are properties that change spatially and will affect how the mobility of PTEs in a specific soil may be impacted by flooding. As a result, knowledge based on one river catchment may not be particularly useful for predicting the impacts of flooding at another site. This review provides a critical discussion of the mechanisms controlling the mobility of PTEs in floodplain soils. It summarises current understanding, identifies limitations to existing knowledge, and highlights requirements for further research.

Denitrification in floodplain soils is one key process that determines the buffering capacity of riparian zones in terms of diffuse nitrate pollution. One widely used approach to measure the denitrification potential is the acetylene inhibition technique that requires fresh soil samples. We conducted experiments with air-dried soils using a time series analysis to determine the optimal rewetting period. Thus, air-dried soil samples from six different floodplain areas in Germany were rewetted for 1 to 13days to 100% water-filled pore space. We analyzed nitrogen accumulated as N2O in the top of anaerobic flasks with and without acetylene by gas chromatography after four hours of incubation. We observed an overall optimal rewetting of at least seven days for complete denitrification. We also saw the strong influence of pH and field capacity on the denitrification product ratio, in soils with pH &lt, 7, we hardly assumed complete denitrification, whereas the treatments with pH &gt, 7 achieved stable values after seven days of rewetting. This advanced method provides the opportunity to carry out campaigns with large soil sample sizes on the landscape scale, as samples can be stored dry until measurements are taken.

The northwestern part of the Acre State (Brazil) possesses singular soils in Brazilian Amazonia, but have been very little studied. This study aimed to discuss the genesis and some micropedological aspects of the soils from Serra do Divisor and adjacent floodplain soils of the Moa river, to enhance the knowledge on their formation. A toposequence of soils ranging from the uppermost part of sub-Andean Serra do Divisor to the Alluvial soils of Moa river floodplain was studied, regarding chemical, physical, mineralogical, and micromorphological attributes. The parent material of the Serra do Divisor is basically quartzose sandstone, and the soils along the toposequence were classified as Typic Haplorthods (P1), Spodic Quartzipsamment (P2), Lithic Quartzipsamment (P3), and Lithic Quartzipsamment (P4). Along the Moa river floodplain, we also identified and collected, Typic Udifluvent (P5), Typic Kandiudult (P6), Typic Kandiudalf (P7), and Arenic Plinthic Kandiudult (P8). The Serra do Divisor soils have very low fertility, high acidity, and low cation exchange capacities, presenting a coarse sandy texture, even shallow pedons. The X-ray diffraction analysis of these soils indicates the predominance of kaolinite, with traces of quartz and gibbsite. The shallow mountain Podzols on sandstone have an expressive accumulation of organic material in surface horizons, with evidence of ferrihydrite and imogolite in the subsurface. At the Moa river floodplain, all soils are originated from recent sediments (Cenozoic), which have a geological source upstream. Varying sedimentary layers are key aspects influencing soil genesis. Those soils have evidence of 2:1 clays with hydroxyl-Al interlayers in subsurface horizons. The Serra do Divisor steep landforms and the coarse texture of the soils promote good drainage and favor leaching and chemical impoverishment. Kaolinite and gibbsite were formed by severe leaching and there are evidences of in situ neoformation of gibbsite by extreme Si losses. All studied soils have some peculiarities such as high accumulation of organic material or 2:1 clay minerals. Most investigated soils were affected by colluvial, reworking, mass movements or a strong variation on sedimentation. Made available in DSpace on 2020-09-01T04:41:32Z (GMT). No. of bitstreams: 1 27023.pdf: 8321405 bytes, checksum: eefac5e697251c464a1a8584ea3f5456 (MD5) Previous issue date: 2020

For south ‘Wessex’, despite complexity evident on the ground, there is little research that directly links river channel form with historic economic development; that is, channel genesis and planfo...

The chemical fractionation of nine metals, Cd, Pb, Cr, Ni, Cu, Co, Ba, Mn and Zn, in soil profiles of the floodplain of the lower reaches of the River Niger in Nigeria, was investigated with a view to providing information on the forms, bioavailability and mobility of these metals in the soil profiles. The chemical forms of metals in the soil were determined by using the European Community Bureau of Reference (BCR) sequential chemical extraction method and the concentrations were measured by inductively coupled plasma-atomic emission spectrophotometry (ICP-AES). The results indicated that the residual and Fe-Mn oxide/hydroxide phases were the predominant forms of the metals in the soil profiles. The percentage of metals in the readily available and potentially available fractions followed the order: Pb > Ba > Cd > Ni > Co > Zn > Mn > Cu > Cr. Significant proportions of these metals were found in the potentially available phases, which indicate an increase in mobility and availability as a result of change...

Rice crops uptake large amounts of potassium (K), which is mainly supplied from inorganic fertilizer. Alternate K sources are essential to preserve natural reserves and to recycle unused K containing stubbles. We have evaluated the performance of rice straw (RS) in farmers’ field following integrated plant nutrient system (IPNS) for supplementing K requirement of rice and compared with agro-ecological zone (AEZ)-based chemical fertilizer and farmers’ practice in Tista Meander Floodplain soils of Bangladesh during 2013–2015. Application of RS @ 4.5 t ha−1 + IPNS-based fertilizer replaced full dose of chemical K fertilizer without significant reduction in grain yield of Boro rice. The K uptake with RS incorporation was similar to AEZ-based chemical fertilizer use. Considering soil health and environmental issue, RS + IPNS-based fertilizer management was the best option for growing wetland rice.

Data on strontium accumulation acquired by studying the floodplain soils of the Kuda River, Irkutsk Region, show that the bulk accumulation of this element and the accumulation of its water-soluble species are controlled by evaporative concentration. Floodplain areas maximally enriched in water-soluble strontium are defined. These areas are the most potentially hazardous if involved in agricultural activities because Sr can be transferred there into the surface- and soil–groundwaters in concentrations several times higher than the maximum permissible concentrations of this element in water bodies.

A coal storage wharf located in Zhenjiang, Jiangsu province, China, has a planned annual capacity of 15 million tons. The thick Yangtze River floodplain is rich in muddy-silty clay with hig...

Lateral movements of soil organic C (SOC) influence Earth's C budgets by transporting organic C across landscapes and by modifying soil-profile fluxes of CO2. We extended a previously presented model (Soil Organic C Erosion Replacement and Oxidation, SOrCERO) and present SOrCERODe, a model with which we can project how erosion and subsequent deposition of eroded material can modify biosphere-atmosphere CO2 fluxes in watersheds. The model permits the user to quantify the degree to which eroding and depositional profiles experience a change in SOC oxidation and production as formerly deep horizons become increasingly shallow, and as depositional profiles are buried. To investigate the relative importance of erosion rate, evolving SOC depth distributions, and mineralization reactivity on modeled soil C fluxes, we examine two forests exhibiting distinct depth distributions of SOC content and reactivity, hydrologic regimes and land use. Model projections suggest that, at decadal to centennial timescales: (1) the quantity of SOC moving across a landscape depends on erosion rate and the degree to which SOC production and oxidation at the eroding profile are modified as deeper horizons become shallower, and determines the degree to which depositional profile SOC fluxes are modified; (2) erosional setting C sink strength increases with erosion rate, with some sink effects reaching more than 40% of original profile SOC content after 100 y of a relatively high erosion rate (i.e., 1 mm y−1); (3) even large amounts of deposited SOC may not promote a large depositional profile C sink even with large gains in autochthonous SOC post-deposition if oxidation of buried SOC is not limited; and (4) when modeled depositional settings receive a disproportionately large amount of SOC, simulations of strong C sink scenarios mimic observations of modest preservation of buried SOC and large SOC gains in surficial horizons, suggesting that C sink scenarios have merit in these forests. Our analyses illuminate the importance of cross-landscape linkages between upland and depositional environments for watershed-scale biosphere-atmosphere C fluxes, and emphasize the need for accurate representations and observations of time-varying depth distributions of SOC reactivity across evolving watersheds if we seek accurate projections of ecosystem C balances.

CORRECTION: Due to a number of formatting and layout issues, the PDF of this paper was replaced on 10th October 2016. The page numbers of this article have changed from 55-61 to 57-63. The present investigation aimed to evaluate different fractions of P of Ganges tidal floodplain soils of Bangladesh in terms of plant availability in the selected soil. The samples were analyzed for solution P, labile pool, alkali-extracted inorganic pool, organic pool, acidic pool and residual P.The soil solution P in the tested soils ranged from 0.03 to 0.11 mg L –1 . The concentration of 0.5M NaHCO 3 extracted P had a range of 8-34 mg kg –1 . Dilute NaOH extracted inorganic P had a range of 25-59 mg kg –1 . NaOH extracted organic P ranged from 334 to 542 mg kg –1 and acid extracted P represented from 140 to 443 mg kg –1 , respectively. Residual P of the tested soils showed a concentration of 104-262 mg kg –1 . On average of the 12 soils, the relative concentration of solution P was 0.01%, NaHCO 3 P was 3.2%, NaOH-Pi was 6.8%, NaOH-Po was 44.6%, acid pool was 27.3% and residual fraction was 18.1%. Different P pools showed strong correlation either with sand, silt, clay, electrical conductivity, pH(H 2 O), pH (KCl), organic carbon or extractable Fe content. The tested Ganges tidal floodplain soils demonstrated wide variation in the relative proportion of different P pools. Bangladesh Rice j. 2015, 19(2): 57-63

The study was set up to characterize floodplain soils of Southern Guinea Savanna in North Central Nigeria for sustainable land use. The flexible grid method was adopted to identify the soil units. Soil map was produced in a GIS environment, using morpho-physical and soil chemical properties. The major morphological expressions are ferrolyses and gleization. The variation in cation exchange capacity recorded (1.29–21.64 cmol kg− 1) could be attributed to effects of various deposits of soil regoliths from time to time. The phosphorus distribution is generally low (0.8–11.8 mg kg− 1) while nitrogen content is > 0.15% at the surface. The major pedogenetic processes include cummilization, ferrolyses and gleization. The soil units identified were classified as Fluvaquentic Epiaquept, Aquertic Ustifluvent, Kandic Ustifluvent, and Aeric Ustipsamment. The mapping units suggest two possible management units based on texture and chemical properties. The soils are generally suitable for rice production due to epi-saturation.

Microplastics (MPs) are small (5 mm diameter) but have clear implications for the environment. These artificial particles are found in and pose threats to aquatic systems worldwide. MPs have terrestrial sources, but their concentrations and fates in the terrestrial environment are poorly understood. While global plastic production continues to increase, so do the environmental concentrations and impacts of MPs. In this first study of MPs in floodplain soils, we developed a method for identifying, quantifying, and measuring the sizes of most commonly produced MPs in soil by FT-IR microscopy. For small MP (1 mm) analysis, MP were separated by density separation and oxidation of organic matter. In this study we analyzed 29 floodplains in Swiss nature reserves associated with catchments covering 53% of Switzerland. We found evidence that 90% of Swiss floodplain soils contain MPs. The highest MP concentrations were associated with the concentration of mesoplastics (5 mm - 2.5 cm diameter), indicating plastic waste as source. Furthermore, MP concentration was correlated with the population of the catchment. The wide distribution of MPs, their presence in remote unsettled high mountain areas, decoupling of MEP and MP compositions, and the dominance of MPs by small (500 μm diameter) particles, indicate that MPs enter soils via diffuse aeolian transport.

On the earthworm fauna (Oligochaeta: Lumbricidae), in particular the distribution of Proctodrilus, in the floodplains of the chernozem and gray-brown podzolic soil areas on both sides of the Ore Mts. In a study of mineral soils in floodplains, shallow depressions, and dry valley heads of the Saale-Elster plateau in eastern Germany and along the lower Eger/Ohře river in Czechia, sixteen earthworm species were found. On the basis of these findings, areas of gray-brown podzolic soils can be differentiated from chernozem areas mainly by the occurrence in the former of the two species Proctodrilus antipai and P. tuberculatus. In a section of one floodplain in the gray-brown podzolic soil area, the distribution of these two earthworm species shows a vicariance situation, such that P. antipai is restricted to the outer edges of the floodplain while P. tuberculatus inhabits the parts close to the river. In the chernozem areas, on the other hand, P. antipai is the only one of the two species to occur, and is also found in those areas close to the river. P. tuberculatus disappears in the transitional zone between a floodplain where it occurs and a chernozem floodplain. The distribution of P. antipai ends where a floodplain inhabited by it graduates into one belonging to a large river with a high rate of flow. On the stretch of the Elbe near Mlekojedy, where the position of the confluence with the Ohře has migrated over time, the vicariant distribution of the two species within the soil profile was noted. Here P. antipai is found in the uppermost soil layer, while P. tuberculatus lives in the lower-lying mineral soil at the same location. This ecological vicariance appears to represent different stages of clay translocation in flood loam. The results show that P. tuberculatus is dependent on such clay translocation or lessivage, and where this soil-profile-influencing process cannot take place the species does not occur. Examples would be oligotrophic acid montane brown forest soils, eutrophic brown forest soils, and chernozems, as well as the floodplain soils derived from all three.

Soil profiles from 0 to 80 cm depth were collected at five typical zones (including permanently flooded floodplain (B), 1-year floodplain (O), 5-year floodplain (F), 10-year floodplain (T), and 100-year floodplain (H)) which are divided by different flooding frequencies along the direction penperdicular to the river channel in different floodplain wetlands of Xianghai National Nature Reserve of China. A 14-day incubation experiment was carried out at 25°C in the dark to reveal the effects of different flooding frequencies on nitrogen mineralization rates. Our results showed that nitrogen mineralization rates showed an alternative tend of “increasing and decreasing”in the soil profiles at five sampling zones except the 1-year floodplain and permanent floodplain. The nitrogen mineralization rates were lower in permanently flooded floodplain soils compared to another four floodplain wetlands with different flooding frequencies. Additionally, nitrogen mineralization rates were significantly correlated with electrical conductivity, total soluble salt, pH values and salinity.

This study was conducted at farmers’ fields in Chandina, Cumilla of Bangladesh covering soils of Old Meghna Estuarine Floodplain to find the effect of micronutrient application to tomato in floodplain soils. Randomized complete block design with 3 replications was used in the experiment where seven treatments including a control were tested. The treatments were formulated taking six micronutrients, i. e., Zn, B, Cu, Mn, Fe and Mo at the rate of 3, 2, 2, 3, 5 and 1 kg ha-1, respectively. The treatments were designed following the additive element trial technique and N, P, K and S were applied at recommended rate equally to all plots. Fruit yield of tomato was affected significantly by the application of Zn alone but combine application of both Zn and B showed the highest responses. It was evident that the application of only Zn and B was sufficient to achieve a tomato fruit yield of 66.4 t ha-1 that was similar to the highest yielding (67.5 t ha-1) treatment (T7). The lowest yield (56.8 t ha-1) was in the control treatment. Stover yield and plant height did not respond significantly while only Zn was found responsive for fruit yield, fruit clusters and number of fruits per plant. Similar to fruit yield, protein content and in all cases, nutrient uptake were affected by the application of both Zn and B. It was noted that the application of Zn and B influenced different growth and yield parameters while the other four micronutrients tested did not have any effect. However, the combine application of Zn, B, Cu, Mn, Fe and Mo was beneficial for plant growth.

Phosphorus (P) availability, which depends on both P concentration and speciation, often controls primary productivity and algal-bloom formation in river systems. The river P pool is also connected to P pools of adjacent sediments, soils and vegetation. Thus, informed management of P in floodplain–river systems requires detailed understanding of P concentration and speciation in all of these interconnected components. We studied P speciation in river sediments and water, floodplain soils and river red gum (Eucalyptus camaldulensis) leaf litter from the Lower Murray region using conventional spectroscopic measurements, solution 31P nuclear magnetic resonance (31P NMR) spectroscopy, and leaching experiments to simulate floodplain re-wetting of leaf litter. Almost all (>85%) of the P in river sediments was in the orthophosphate form, whereas floodplain soils had higher proportions of organic P (PO) species. Both fresh and senescent river red gum leaf litter also had a much higher concentration of PO, primarily in the form of phytate. On submersion, there was a rapid (0–96h) loss of dissolved P from senescent leaves; release of dissolved organic carbon showed similar kinetics. Loss of P from the leaves included both organic and inorganic forms. The results have important implications for aquatic primary productivity and environmental management strategies.

Fractions studies were done to know how the zinc applied to different soils was distributed in to various fractions when the soils incubated under aerobic and anaerobic condition. The added zinc provided significant increase in exchangeable Zn both under aerobic and anaerobic conditions although anaerobic condition gave lower results than aerobic condition. The higher results were obtained at early stage of incubation and it gradually reduced as the incubation period proceeded to 90 days. These results showed all most similar trends for all the soils under study. In general, added zinc showed significantly higher results to the different fractions of soil Zn both under anaerobic and aerobic incubation with very few exceptions. The highest amount of added Zn (12 kg/ha) always produced greater results than the lower doses. Only exchangeable Zn was found higher in the 1st measurement at 15 DAI then gradually decreased but in other cases, gradual increase in zinc fractions was seen as the incubation study proceed to longer duration provided with very few exceptions. In many cases, the exchangeable-Zn found higher only at 15 DAI but sharply reduced at 30 DAI. In general, the Gray Terrace Soil produced the highest results followed by Non Calcareous Gray Floodplain and the lowest results were observed in Dark Grey Floodplain & Brown Floodplain Soil. DOI: http://dx.doi.org/10.3329/jsf.v9i1-2.14643 J. Sci. Foundation, 9(1&2): 9-15, June-December 2011

The experiment on wheat to zinc fertilization was carried out at the Regional Agricultural Research Station, Agricultural Research Sub-Station, and Special Crop Research Stations of BARI and at Farmer’s field. The grain yield was increased with increasing application of zinc upto 6 kg/ha but beyond that the level the yield was declined. The highest yield (3.87t/ha) was obtained in 6 kg Zn/ha under Amnura series as compare to Nachole and Lauta series. The lowest yield was obtained in Nachole series (3.07 t Zn/ha) under Deep Grey Terrace Soil. In Gangachara too, the grain yield of wheat was increased with increasing levels of zinc upto 6 kg Zn/ha beyond that it was declined. The highest yield (5.58t/ha) was obtained in 6 kg Zn/ha under Gangachara series and compare to Kaunia and Sonatola series. The lowest yield was obtained (3.92t/ha) in Kaunia series under Grey Floodplain Soils.The grain yield of wheat was significantly increased upto 12 kg Zn/ha in Calcarious Dark Grey Floodplain and Calcarious Brown Floodplain Soils and the order of increase was Zn12>Zn9>Zn6 >Zn3>Zn0. The highest yield (5.50 t/ha) was recorded in 12 kg Zn/ha. The order of the yield was Ishardi 5.50 t/ha > Sara5.47 t /ha> Gopalpur 5.13 t /ha>Darsona 2.91t/ha was recorded under Calcarious Dark Grey Floodplain and Calcareous Brown Floodplain Soils. DOI: http://dx.doi.org/10.3329/jsf.v9i1-2.14644 J. Sci. Foundation, 9(1&2): 15-25, June-December 2011

The growing concern over phosphorus (P) and water quality has led to questions as to where the loads originate and how to control landscape inputs from the watershed. We collected soil cores from two locations in the Illinois River watershed to examine the relationship between stored soil P and the amount of soluble reactive P (SRP) released into the water when soils are flooded. After inundation, P flux calculations for durations of ∼24 h ranged from less than 0.1 to 9.3 mg SRP m h. Soil test P (STP), measured as water-extractable P and Mehlich-III P, correlated with SRP flux, where higher STP resulted in increased P flux to the overlying water. Floodplain soils have the potential to be a P source, potentially releasing more than 1600 mg m yr (>16 kg ha yr) depending on length and frequency of inundation and on STP content. Applying water treatment residuals (WTRs) significantly reduced P flux from the cores. Hence, WTR application to critical source areas provides a mitigation strategy to manage floodplain soils and potential SRP release.

The concentrations of the USEPA 16 priority polycyclic aromatic hydrocarbons (PAHs) in soils of the floodplain of the lower reaches of River Niger, Nigeria, were investigated following the Lagdo Dam flood disaster of 2012. The aim was to provide information on the extent of contamination, sources, and risks of PAHs in these soils. The concentrations of Σ16 PAHs in the floodplain soils ranged from 812 to 10,700 μg kg. The benzo(a)pyrene (BaP) toxic equivalence and incremental lifetime cancer risk (ILCR) factors were used to evaluate the risk of human exposure to PAHs in these soils. The concentrations of benzo(a)pyrene carcinogenic equivalence (BaP) and benzo(a)pyrene mutagenic equivalence (BaP) ranged from not detected to 4090 μg kg and not detected to 4150 μg kg, respectively. The total ILCR for children and adults was calculated as the summation of the individual risks through the three routes of exposure, (ingestion, dermal, and inhalation of vapor or dust). The values obtained indicate that there are 6450 and 4480 chances in one million equally exposed persons to develop the risk of cancer for children and adults, respectively, which were higher than the USEPA acceptable guideline value of one cancer case in one million (10) equally exposed persons. The PAHs source evaluation, using the diagnostic ratios and principal component analysis (PCA), indicated that the major sources of PAHs in these soils were fossil fuel combustion, gas flaring, wood combustion, traffic emissions, and input from petroleum.

Accumulation of heavy metals has become a serious environmental issue in China, especially in the floodplains downstream from mining and smelting sites. Estimation of total iron Fe content at the regional scale becomes particularly important because of the heavy metal sorption of Fe oxide. A novel method for estimating total Fe content is proposed using visible and near-infrared VNIR spectroscopy and partial least squares regression PLSR. Our study focuses on the Le'an River floodplain, Jiangxi Province, China, which houses the largest copper mining corporation in China, as this area has suffered a series of environmental setbacks because of the extraction of non-ferrous metals. Our study employs PLSR to summarize the relationship between VNIR reflectance spectra and the total Fe contents of collected soil samples. More specifically, our study aims to 1 explore the correlation between VNIR and total Fe content, 2 assess the relationship between VNIR determination of total Fe content and the preprocessing of soil samples and 3 evaluate the performance of data transformation methods in PLSR. The PLSR model with transformed total Fe content and continuum removal spectra was finally chosen for estimating the total Fe content from both pretreated soil samples coefficient of determination for prediction, = 0.66 and soil samples without pretreatment = 0.55. Therefore, VNIR spectroscopy could be an alternative method for estimating total Fe content at the regional scale.

This study investigated Hg uptake from soil into garden crops to help assess the significance of human consumption of crops as a potential route of exposure to Hg. Locations for both a floodplain and a control garden were identified within the Augusta Forestry Center near Crimora, VA, USA, which is about 16 river-km downstream from the city of Waynesboro, along the South River. The floodplain garden had measured soil Hg concentrations ranging from 4.2 to 78 mg Hg kg−1 dry weight basis in the surface to 15-cm deep layer. A total of 139 samples from the floodplain garden from 17 different crops were analyzed for Hg. All crop samples (except for nine) had less than 0.1 μg Hg g−1 wet weight basis (ww). Many samples were less than the method detection limit (MDL) of 0.003 μg Hg g−1 ww. Based on the measured Hg concentrations and several conservative assumptions (e.g., Hg assumed present when less than MDL; 100% consumption from the geographical area in which study was conducted; and 100% bioavailable ...

The morphological properties of floodplains and their morphological classification are shown from the generalization of long-term studies. A detailed description of alluvial processes is given, and stages of alluvial soil formation are characterized. Zonal-geographic, hydro-geomorphologic, evolutionary, and geomorphologic-genetic regularities in soil geography are found. The properties of alluvial soils under sharply contrasting climatic conditions, e.g., humid and arid, are considered. The high biogenic ability of soils and intensity of the soil-forming process in floodplains are proved. Data characterizing the structure and properties of floodplain soils in particular river valleys and the main micromorphological diagnostic features of alluvial soils are given.

The species composition and structure of collembolan communities in floodplain soils were analyzed; a total of 65 species were found. The highest springtail species diversity was revealed in soils of birch-aspen forests. Collembolan communities in meadow soils were the most similar to those in the aspen forests of the second and third age classes. Prevalence of edaphic and hemiedaphic species is characteristic of soils of birch-aspen forests.

Two long-term submerged Eutric Gleysols (GLe) and two short-term flooded Eutric Fluvisols (FLe) with high organic carbon contents (Corg between 5.1 and 12.9%) were selected to characterize soil microbial communities at the Elbe River (Germany). Measurements included dehydrogenase activity (DHA), soil microbial carbon (Cmic), soil basal respiration (BR), metabolic quotient (qCO2), Cmic/Corg ratio, and phospholipid fatty acids (PLFA). PLFA biomass, DHA, and Cmic/Corg ratios were considerable lower in GLe's than in FLe's. Whereas the BR as well as qCO2 were higher in GLe's what seems to be an unspecific response of aerobic soil microorganisms to the long flooding period and the resulting short time for development following flooding. Cmic/Corg ratios were low in comparison to terrestrial soils. PLFA profiles were dominated by saturated fatty acids (FA). Principal component analyses (PCA) of FAs revealed clear differences among the four floodplain soils. In GLe's all fractions of PLFAs were lower tha...

Specific features of the soil cover in the lower reaches of the Ob River are analyzed. The physicochemical properties and composition of the floodplain soils in different parts of the valley and on different floodplain elements are given. A comparative geographical analysis of the accumulation of macro-and microelements in the floodplain soils as a result of alluviation processes in the middle and lower reaches of the Ob River is suggested. The evolution of the floodplain soils and the results of the development of stratified humus horizons, changes in the hydrological regime, and cessation of floods are discussed.

Gleyzation-mediated leaching of radiostrontium from floodplain soils of the Krasnoyarsk Mining and Chemical Combine (MCC) activity zone [Atamanovskii Island (front part), Oseredysh Island (front part), and Berezovyi Island (rear part)] is studied with model systems. Leaching of radiostrontium from waterlogged soils is analyzed in terms of the model of anaerobic biosolubilization of gel films. The leaching of radiostrontium is found to correlate with that of iron, confirming the cosolubilization model. Addition of glucose (0.5%) as a stimulant for growth of iron-reducing microorganisms increases the dynamic coefficient of radiostrontium leaching, particularly in soils with lower organic matter content. The model experiments showed that the radiostrontium leaching rate from floodplain soil is higher by 2–3 orders of magnitude than that of radio-cesium, suggesting the possibility of escape of radiostrontium from the floodplain of the Yenisei River with the intrasoil runoff. This conclusion is supported by the experimental data on the 90Sr/137Cs ratio in the floodplain of the Yenisei River downstream of MCC (0.01–0.1).

The Vistula is the second largest river in the Baltic Sea catchment area and provides one of the main inputs to the Baltic. The river and its tributaries flow through some of the major industrialized and urbanised regions of Poland, making it one of the most highly human-impacted rivers in Europe. Although the river status is monitored routinely, little is known about mercury forms in the sediments. This study examines mercury fractionation in the sediments of the lower part of the Vistula River. The results show that the cities along this stretch of river have a relatively low impact on both the mercury forms found in the sediment and its bioavailability in the floodplain soils. The mean concentration of total mercury in the sediments was 65 ± 14 ng g-1 dry mass (range 54-92), calculated as the sum of mercury concentrations in the individual fractions. The most abundantly represented of these fractions were mercury bound to sulphides (68 ± 11%, range 55-82%) and humic matter (19 ± 10%, range 10-35%), with lower fractions of water-soluble mercury (6.9 ± 2.9%, range 5.1-13%) and organomercury compounds (6.4 ± 5.3%, range 0.6-13%). The least abundant fraction observed was acid-soluble mercury (0.3 ± 0.2%, range 0.1-0.6%). Similar concentrations and fractionation were observed in floodplain soils from Kiezmark, collected 1, 10 and 50 meters from the riverbed.

The distribution of earthworms in 18 types of tundra, middle-taiga, alas, and floodplain soils of Yakutia has been studied. The species Eisenia nordenskioldi is typical of Yakutian soils. The area, population density, and seasonal dynamics of earthworms in permafrost-affected soils have been determined. It is shown that earthworms are absent in excessively moist peat-muck permafrost-affected soils, excessively dry soddy soils of alases (thermokarst depressions), and soddy alluvial soils under steppe communities. The best living conditions for earthworms are associated with meadow floodplain, meadow alas, and mucky calcareous soils.

Although the qualities of the river water and the sediments of the river Elbe have greatly improved over the past twenty years, both the suspended matter and the sediments are still contaminated with heavy metals and arsenic (HM). This contamination exceeds the action values specified in the Federal Soil Protection and Contaminated Sites Ordinance (BBodSchV). The status of floodplain soil contamination with HM along the entire German alluvial Elbe was investigated and evaluated, based on former research activities and recently performed analyses after the extreme flood event in August 2002 and the subsequent winter flooding. The section downstream of the river Mulde inflow was contaminated much higher than the upstream section. With the installation of permanently marked observation areas a tool for soil quality monitoring has been established for the future. Die hochwasserbedingte Belastung der Auen mit Schwermetallen und Arsen entlang der Elbe Obgleich sich die Flusswasser- und Sedimentqualitat der Elbe in den letzten 20 Jahren erheblich verbessert haben, sind die Schwebstoffe und schwebstoffburtigen Sedimente immer noch hoch mit Schwermetallen belastet. Dies fuhrt bei Bodenbildungen aus diesen Substraten haufig zur Uberschreitung der in der Bundesbodenschutz- und Altlastenverordnung (BBodSchV) festgelegten Masnahmewerte. Basierend auf fruheren Untersuchungen und aktuellen Erhebungen wahrend des extremen Hochwassers vom August 2002 und des folgenden Winterhochwassers wurde der gegenwartige Belastungsstatus der Boden in den Uberflutungsgebieten entlang der gesamten deutschen tidefreien Elbe ermittelt und bewertet. Dabei war der Flussabschnitt unterhalb der Muldemundung wesentlich hoher als der oberhalb gelegene belastet. Durch die Anlage dauerhaft markierter Beobachtungsflachen wird es ermoglicht, in Zukunft Veranderungen des Stoffbestandes exakt zu erfassen.

The rare earth elements (REE), particle-size distribution and mineralogical composition in the

Am and Pu speciation in floodplain soils and bottom sediments of the Yenisei River is studied. Pu is more tightly associated with amorphous hydroxides as compared to Am. Am associated with organic matter is potentially more mobile than Pu. Model experiments showed that fulvic acids decelerate Am sorption from water to floodplain soil.

The contents of 90 Sr and 137 Cs and the pattern of their redistribution in the soil and plant cover of floodplain ecosystems have been assessed. It is shown that the radionuclide distribution across the floodplain and along the river flow is determined by the formation of a barrier to their migration near the river channel, at which less mobile 137 Cs accumulates. The soil and plant cover of the central floodplain are enriched with 90 Sr. Differences in radionuclide migration in floodplain soils and their input into plants are determined by the rela- tionship between the processes of their immobilization and migration with soil water.

Soil sediment samples of 10 layers with a spacing of 10 cm each were collected in different floodplain zones adjacent to Huolin River in the Xianghai Nature Reserve, and contents of total N, total P and organic matters were analyzed. The results showed that contents of total N, total P and organic matters were generally decreasing with the increase of distance from sample locations to the river channel, and contents of the three items were generally higher in the upper soil layer than that in the lower soil layer. The content variations displayed how flooding functions influenced nutrient matter content variations in floodplain soils since the flood inundation frequencies of the sample locations varied. The correlation analysis displayed that there were remarkable relativities between total N, total P and organic matters within definite spatial distance from the Huolin River channel.

Measuring soil organic carbon (SOC) in riparian forest soils affected by floods is crucial for evaluating their concentration and distribution along hydrological gradients (longitudinal and transversal). Hydromorphological factors (e.g., sedimentation vs. erosion, size of floodplain, flood recurrence) may be the cause of major variations in the concentration of organic matter and SOC in soils and could have a direct impact on C levels in soil profiles. For this study, SOC concentrations were assessed in riparian soils collected along transects perpendicular to the riverbanks which cross through inundated and non-inundated zones. Other soil properties (e.g., acidity, nitrogen, texture, bulk density) that may affect the concentration of SOC were also considered. The main purpose of this study was to assess SOC concentrations in soils subjected to flooding with those outside the flood zones, and also measure various soil properties (in surface soils and at various depths ranging from 0 to 100 cm) for each selected area. Across the various areas, SOC shows marked differences in concentration and spatial distribution, with the lowest values found in mineral soils affected by successive floods (recurrence of 0–20 years). SOC at 0–20 cm in depth was significantly lower in active floodplains (Tukey HSD test), with average values of 2.29 ± 1.64% compared to non-inundated soils (3.83 ± 2.22%). The proportion of C stocks calculated in soils (inundated vs. non-inundated zones) was significantly different, with average values of 38.22 ± 10.40 and 79.75 ± 29.47 t·ha−1, respectively. Flood frequency appears to be a key factor in understanding the low SOC concentrations in floodplain soils subjected to high flood recurrence (0–20 years).

This document is the final technical report for a project designed to address fundamental processes controlling the release of mercury from flood plain soils associated with East Fork Poplar Creek, Tennessee near the U.S. Department of Energy Oak Ridge facility. The report summarizes the activities, findings, presentations, and publications resulting from an award to the U.S. Geological that were part of a larger overall effort including Kathy Nagy (University of Illinois, Chicago, Ill) and Joseph Ryan (University of Colorado, Boulder, CO). The specific charge for the U.S.G.S. portion of the study was to provide analytical support for the larger group effort (Nagy and Ryan), especially with regard to analyses of Hg and dissolved organic matter, and to provide information about the release of mercury from the floodplain soils.

International audience; Flood pulses are major drivers of river-floodplain processes. We investigated their effects on soil nitrogen (N) transformations along a lateral gradient from the river to a mature alluvial forest in the Thur River floodplain (NE Switzerland). Selected N pools (ammonium and nitrate) and N transformations (mineralization, nitrification and denitrification) in the topsoils were repeatedly quantified over a period of six months. During this period, the floodplain was affected by two flood events of different magnitude. Our results showed a distinct difference in size and temporal changes of N pools and transformation rates among functional process zones (FPZs) differing in flooding disturbance. A strong temporary increase in N mineralization in a FPZ with young soil on the frequently flooded gravel bars was the most prominent flood-related effect. This was most likely related to the fast-flowing water during inundation that deposited fresh dispersed sediments with a coarse sandy texture containing highly bioavailable organic N, and/or stimulated the turnover of existing N by destroying sediment aggregates already present before the flood. Increased N mineralization appeared to stimulate coupled nitrification-denitrification in this FPZ during the drying phase. In the more stable FPZs, N mineralization was not strongly enhanced by flooding, whereas nitrification and denitrification were also increased during the drying phase, however to a lesser degree than in the gravel bar soils. Based on our results we propose that floodplain zones characterized by short intensive floods with fast over-flowing water are "hot spots" and the drying phases after the floods are "hot moments" of N transformations.

study area was assessed with respect to its heavy-metal load on the basis of the current guideline values. The heavy-metal loads of the soils in the study area have ranges of

A novel mercury-specific sequential extraction procedure (SEP) for the assessment of mercury (Hg) speciation in soils and sediments, with emphasis on studying the interaction between Hg and organic matter (OM), was developed and tested. It was applied to determine Hg speciation in floodplain topsoils and surface sediments along the Hg-contaminated part of the river Elbe, and to simultaneously derive some information on the (re)mobilization potentials for Hg from these matrices. The majority of the total Hg in the ecosystem today is bound in the floodplains, which also still geographically reflect the historic emission record. Most of the Hg in both matrices is bound strongly to OM, suggesting low availability. However, distinct differences between Hg speciation in the floodplain soils and sediments were also discovered. Mercury deposited in the floodplains shows speciation patterns that indicate stronger fixation compared with Hg in the sediments. This difference is attributed to the association of Hg with larger quantities of OM, which presumably also has higher molecular weight (MW). By comparison, Hg in the sediments was distributed among weaker binding forms, which are more likely to liberate Hg. Particularly, sediments showed a total lack of sulfidic binding forms for Hg. Pronounced geographical trends were detected in the Hg speciation along the river transect, with a general downstream shift from weaker to stronger binding forms, probably due to increased association with OM. These studies indicate that Hg speciation in riverine ecosystems is dynamic and reflects the chemical mechanisms underlying (bio)geochemical processes like distribution and transport.

Environmental pollution by mercury is a world-wide problem. Particularly floodplain ecosystems are frequently affected. One example is the Elbe River in Germany and its catchment areas; large amounts of Hg from a range of anthropogenic and geogenic sources have been accumulated in the soils of these floodplains. They serve as sink for Hg originating from the surface water of adjacent river. Today, the vastly elevated Hg contents of the floodplain soils at the Elbe River often exceed even the action values of the German Soil Conservation Law. This is especially important as Hg polluted areas at the Elbe River achieve several hundred square kilometres. Thus, authorities are coerced by law to conduct an appropriate risk assessment and to implement practical actions to eliminate or reduce environmental problems. A reliable risk assessment particularly with view to organisms (vegetation as green fodder and hay production, grazing and wild animals) to avoid the transfer of Hg into the human food chain, requires an authentic determination of Hg fluxes and their dynamics since gaseous emissions from soil to atmosphere are an important pathway of Hg. However, reliable estimates of Hg fluxes from the highly polluted floodplain soils at the Elbe River and its tributaries, and its influencing factors are scarce. For this purpose, we have developed a new method to determine mercury emissions from soils at various sites. Our objectives were i) to quantify seasonal variations of total gaseous mercury (TGM) fluxes for floodplain soils at the Elbe River, ii) to provide insights into physico-chemical processes regulating these TGM fluxes, and iii) to quantify the impacts of the controlling factors soil temperature and soil water content on Hg volatilization from a typical contaminated floodplain soil within soil microcosm experiments under various controlled temperature and moisture conditions. Our study provides insight into TGM emissions from highly Hg-polluted floodplain soils in Germany and that those emissions are an underestimated problem. Current needs for reliable risk assessments, the induced implications for authorities, and future challenges will be discussed. The presented data will contribute to a better understanding of seasonal dynamics of Hg fluxes and its controlling factors. This presentation should be of large interest for a wide international audience, such as environmental scientists and managers, applied ecologists, and authorities.