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Extensive drainage ditches are constructed to reduce soil salinity in reclaimed saline–alkali farmland, consequently forming plant growth hotspots and impacting soil carbon stocks therein. However, the investigation into changes in soil carbon stocks remains limited in these ditches. To address this, soil samples were collected from drainage ditches, which originated from the reclamation of saline–alkali farmland, at different reclamation years (the first, seventh, and fifteenth year). Moreover, fractions were separated from soil samples; a particle size separation method (particulate organic matter, POM; mineral–associated organic matter, MAOM) and a spatio–temporal substitution method were conducted to analyze the variations in soil carbon components and the underlying mechanisms. The results indicate that there were no significant variations in the contents and stocks of soil organic carbon (SOC) and soil inorganic carbon (SIC) following the increase in reclamation time. However, in the POM fraction, the SOC content (SOCPOM) and stock significantly decreased from 2.24 to 1.12 g kg−1 and from 19.02 to 12.71 Mg ha−1, respectively. Conversely, in the MAOM fraction, the SOC content (SOCMAOM) and stock significantly increased from 0.65 to 1.70 g kg−1 and from 5.30 to 12.27 Mg ha−1, respectively. The different changes in SOCPOM and SOCMAOM, as well as the result of the structural equation model, showed a possible transformation process from SOCPOM to SOCMAOM in the soil carbon pool under the driving force of reclamation time. The results in terms of the changes in soil carbon components demonstrate the stability rather than the stock of the soil carbon pool increase in coastal saline–alkali ditches following the excavation formation time. Although more long time series and direct evidence are needed, our findings further provide a case study for new knowledge about changes in the soil carbon pool within saline–alkali ditches and reveal the potential processes involved in the transformation of soil carbon components. [ABSTRACT FROM AUTHOR]

Heavy metal pollution has received increasing attention worldwide in recent decades. However, the characterization of heavy metal elements in coastal soils has been still poorly understood. In this study, eight metal elements Cd, Cr, Cu, Hg, Ni, Pb, Zn, and As were monitored in coastal soil samples, which were collected from Qingdao on the east coast of China, in 2019. The spatial distribution, pollution level, ecological, and health risks of heavy metals were then evaluated. The experimental results indicated that >50% of the sampling sites for Cd, Pb, Zn, and Hg exceeded the reference background values. In addition, the geoaccumulation index showed that 84%, 96%, and 92% of soil sample sites for Cd, Pb, and Hg were in pollution, respectively; both Cd and Hg had potential ecological risks with 50% and 22% in mild potential ecological risk, 37% (Cd) and 6% (Hg) in moderate potential ecological risk, and <10% the serious potential ecological risk, respectively. Furthermore, the averages of hazard index for all the elements were <1 indicated that the health risks for all eight heavy metals were in low level. Finally, compared with the data of 10 years ago, the concentrations, enrichments, and ecological risks of Pb increased fastest with 17%, 150%, and 17%, respectively. This indicates that with the rapid economic growth of Qingdao, the controlling of Pb in soil should be implemented with a high priority in the near future. [ABSTRACT FROM AUTHOR]

Extensive drainage ditches are constructed to reduce soil salinity in reclaimed saline–alkali farmland, consequently forming plant growth hotspots and impacting soil carbon stocks therein. However, the investigation into changes in soil carbon stocks remains limited in these ditches. To address this, soil samples were collected from drainage ditches, which originated from the reclamation of saline–alkali farmland, at different reclamation years (the first, seventh, and fifteenth year). Moreover, fractions were separated from soil samples; a particle size separation method (particulate organic matter, POM; mineral–associated organic matter, MAOM) and a spatio–temporal substitution method were conducted to analyze the variations in soil carbon components and the underlying mechanisms. The results indicate that there were no significant variations in the contents and stocks of soil organic carbon (SOC) and soil inorganic carbon (SIC) following the increase in reclamation time. However, in the POM fraction, the SOC content (SOCPOM) and stock significantly decreased from 2.24 to 1.12 g kg−1 and from 19.02 to 12.71 Mg ha−1, respectively. Conversely, in the MAOM fraction, the SOC content (SOCMAOM) and stock significantly increased from 0.65 to 1.70 g kg−1 and from 5.30 to 12.27 Mg ha−1, respectively. The different changes in SOCPOM and SOCMAOM, as well as the result of the structural equation model, showed a possible transformation process from SOCPOM to SOCMAOM in the soil carbon pool under the driving force of reclamation time. The results in terms of the changes in soil carbon components demonstrate the stability rather than the stock of the soil carbon pool increase in coastal saline–alkali ditches following the excavation formation time. Although more long time series and direct evidence are needed, our findings further provide a case study for new knowledge about changes in the soil carbon pool within saline–alkali ditches and reveal the potential processes involved in the transformation of soil carbon components.

Soil salinization caused by sea level rise threatens coastal agricultural soils and geochemically important wetlands worldwide. The aim of this review is to outline expected changes in soil biological activity by discussing the combined effects of salt stress and flooding on plants productivity and soil microbial communities, which determine consequences on fluxes of C, N and P. Finally, it outlines the expected repercussions on greenhouse gases emissions. The prediction of outcomes is made difficult by the concomitant and sometimes contrasting actions of flooding and seawater intrusion on partly acclimated and non-acclimated environments. Non-salt acclimated plants suffer from osmotic stress, but also from reduced O2 solubility. Microbial biomass declines with increasing salinity and microbial communities shift in composition. Large concentrations of Cl− inhibit nitrification, but salinity stimulates N2O fluxes. Impacts on C mineralisation rates is variable but enhanced by the larger availability of terminal electron acceptors. The reduction of Fe combined with that of SO42− could enhance P mobility. Salinization affects methanogenesis which is constrained in favour of SO42− reduction. Consequences are largely site specific and difficult to predict because of the complex network of processes occurring simultaneously in different compartments (i.e., soil, microbiome, vegetation). The distinction between short and long term effects is also important. A reliable prediction of outcomes at a planetary scale will only result from more precise inventories and monitoring of areas displaying specific similarities and from the implementation from these well-defined data sets of specifically devised models whose results can be finally combined on a weighted basis.

• The Caspian Sea retreat strongly affected the geochemistry of soils. • The properties of geomorphic surfaces play important roles in soil formation. • Distribution patterns of soil characteristics are strongly affected by landforms and seawater. The objectives of this study are: 1- Determining geochemical characteristics and soil formation processes that lead to soil salinity. 2- To investigate the variability of soil properties across different geomorphic units. The coastal landforms of the Caspian Sea have experienced several seawater retreat and progress in recent decades, which has caused changes in terms of pedology and geomorphology. Routine soil properties, including soil cations and anions (Ca2+, Mg2+, Na+, K+, Cl-, SO 4 2-, CO 3 2–, and HCO 3 –), and total and available forms of some micro-elements (Fe, Mn, Zn, and Cu) of 136 samples collected from 0-20 cm of soils were analyzed according to standard methods. Mapping of the obtained results was done using inverse distance weighting (IDW) in ArcGIS 10.8. The results showed that although the main source of cations and anions in the soil solution is seawater, their concentration and changes in the soil solution are different depending on the processes carried out in soil. Mg2+, Na+, and Cl- were highly enriched in saturated soil extracts compared to seawater (261 %, 153 %, and 149 % respectively). While, K+ and Ca2+, increased by 81 % and 47 % accordingly, and HCO 3 – and SO 4 2-, decreased by −56 % and −25 % due to precipitation of carbonate and gypsum in the soil. Total and available forms of micro-nutrients were high across the study area. The distribution pattern of the total micro-nutrients follows the type of landforms (affecting drainage condition) and their clay contents (mineralogical composition and abundance), however, the available form of micro-nutrients depends on soil moisture conditions and proximity or distance to the coastline. The results showed that the chemistry of seawater is the main factor controlling the chemical and physical properties of soils and their distribution patterns. The geochemical processes of soil formation cause special interactions between the components of soil solution, which leads to the removal of carbonate, bicarbonate, and sulfate from the soil solution and precipitation with calcium as calcium carbonate and calcium sulfate. [ABSTRACT FROM AUTHOR]

In the United States, dangerously high arsenic (As) levels have been found in drinking water wells in more than 25 states, potentially exposing 2.1 million people to drinking water high in As; a known carcinogen. The anticipated sea−level rise (SLR) is expected to alter soil biogeochemical and hydrological conditions, potentially impacting their ability to sequester As. In our study of coastal Wilmington, DE, an area projected to experience a 1 −meter SLR by 2100, we examined the spatial distribution, speciation, and release possibilities of As due to SLR. To understand the complex dynamics at play, we employed a comprehensive approach, including bulk and micro X−ray absorption spectroscopy measurements, hydrological pattern evaluation, and macroscopic stirred−flow experiments. Our results suggest that introducing reducing and saline conditions can increase As release in both river water and seawater inundation scenarios, most likely due to ionic competition and the dissolution of As−bearing Fe/Mn oxides. Regardless of the salinity source, the released As concentrations consistently exceeded the EPA threshold for drinking water. Our results provide valuable insights for developing appropriate remedial and management strategies for this site and numerous others facing similar environmental challenges. With nearly two hundred million individuals living within coastal flood plains and with two million square kilometers of land and one trillion dollars' worth of assets lying less than 1 m above current sea level, sea–level rise (SLR) is one of the significant socio–economic threats associated with global warming. Arsenic is a prevalent contaminant in coastal areas impacted by industrial activities, many of which are susceptible to being impacted by SLR. This study examines SLR's impact on arsenic fate and speciation in a densely populated coastline in Wilmington, DE, expecting 1 meter of SLR by 2100. [Display omitted] • Studied As−contaminated soils response to SLR through hydrogeochemical analysis. • Contaminated urban soils contained up to 6% As hotspots. • Natural seawater and river water inundation increases As release. • Observed As release as high as ca. 200 times more than EPA threshold. • Sea−level rise can significantly contribute to As release. [ABSTRACT FROM AUTHOR]

To study the pollutants immobilization and economy of biologically amended coastal soil, Alternanthera philoxeroides biomass (Bm), biochar (Bc), and dodecyldimethyl betaine (BS) modified Bc (BS-Bc) were used to amend coastal soil from Jialing, Fu, and Qu River. A runoff experiment was used to simulate the longitudinal migration and morphological changes of Pb(II) and chlortetracycline (CTC) in each amended coastal soil, and the economy of pollutants immobilization by different amended coastal soil were compared. The equilibrium time of Pb(II) and CTC in each amended coastal soil ranked in the order of BS-Bc-amended > Bc-amended > Bm-amended > unamended coastal soil. The average Pb(II) and CTC flow rate in different amended coastal soils presented an opposite trend with the equilibrium time. Pb(II) and CTC content all reduced with the increasing runoff length. Under the same soils, the content changes presented Bm and Bc amended > unamended > BS-Bc amended. CEC and clay content of coastal soils were the key factors affecting Pb(II) and CTC immobilization. The immobilization mechanisms were electrostatic attraction, ion exchange, surface precipitation, and complexation to Pb(II) and ion exchange and complexation to CTC. The economy of Pb(II) and CTC immobilization ranged from 0.5 to 9.0 and from 1.0 to 5.4 mg/¥, and coastal soil amended by BS-Bc had practical application value and high economy. • Equilibrium time of Pb(II) and CTC were BS-Bc > Bc > Bm > un- amended coastal soil. • The average pollutants flow rate showed an opposite trend with the equilibrium time. • Pb(II) and CTC content all reduced with the increasing runoff length. • Cation exchange capacity and clay content highly affected pollutants immobilization. • Coastal soil amended by BS-Bc had practical application value and high economy. [ABSTRACT FROM AUTHOR]

Purpose: Rare earth elements (REE) play a prominent role in the understanding of geochemical processes. Lanthanum (La) and neodymium (Nd) are considered as two representative examples of REE. The objectives of this study were to investigate their concentrations and spatial variability in coastal soils and to assess the effect of long-term reclamation. The coastal plain of Cixi City (China) has undergone reclamation for over 1000 years, providing an ideal place to perform such research. Materials and methods: In total, 329 soils samples were collected by means of a nested sampling methodology, combined with grid and transect techniques. The total contents, as well as their diethylenetriamine penta-acetic acid (DTPA) extractable concentrations, were measured by an inductively coupled plasma-mass spectrometry (ICP-MS). Statistics and geostatistics tools were used to analyze their spatial variability. Combined variogram models were developed to quantitatively describe their spatial structure. Variance components were estimated to assess the proportion of their total variance captured by reclamation history and different sampling stages. Results and discussion: Both the La and Nd concentrations showed great variability in space. Reclamation activity accounted for 42–84% of their total variance. There were significant differences in their contents between reclaimed zones (P < 0.05). They exhibited moderate spatial dependence, and the discontinuity in space generally occurred around sea dikes, as indicated by the spherical components of the La and Nd concentration variogram models. A gradually increasing tendency of elemental contents with reclamation time was observed, which was also reflected in the linear component of the variogram models. However, in the areas covered by the 3rd to the 10th zones, intensive application of phosphorus fertilizer, land consolidation, or household appliance factories led to large fluctuations of elemental contents being superimposed on the relatively homogeneous content distributions, thus causing the observed periodic features of their variogram models. Additionally, a 100-m sampling distance was found to be appropriate for future REE investigations. Conclusions: Geostatistical modeling showed a great potential to analyze quantitatively the spatial variability of La and Nd and to assess human forces on soil genesis. The investigation of the spatial distribution of REE identified the prominent role played by the geogenic component. By means of spatial analysis, a time-series of elemental contents on a millennium scale was also reconstructed. Accumulation of their concentrations with time, as well as pollution, occurred in the surface soils. Reclamation history was the most important factor controlling La and Nd spatiotemporal variability. [ABSTRACT FROM AUTHOR]

Coastal soils of Guntur district in Andhra Pradesh are developed from marine sediments. Nutrient status was evaluated for four soil profiles of a coastal village to have information on the nutrient supplying capacity of these soils which is necessary for making accurate fertilizer recommendation in the study area. The nutrient status of the soils indicated that they were low in organic carbon (0.007 to 0.058 g kg-1), available nitrogen (28 to 247 kg ha-1), medium to high in available phosphorus (6.60 to 90.10 kg ha-1) and high in available potassium (241 to 2016 kg ha-1) while concentration of total nitrogen, phosphorus and potassium varied from 100 to 560, 37 to 325 and 625 to 7500 ppm, respectively. Similar trend in sub-surface distribution of organic carbon and total nitrogen revealed the soils were old alluvial soils except profile 2. Sufficiency in available micronutrient content existed except for zinc. Distribution of total micronutrient within the profile showed lower values on surface than subsurface layers indicating fluvial nature of deposition. Relationship of nutrients with organic carbon and clay content were positive while the acidity of the soils resulted in negative affect on micronutrients except copper. Contribution of parent material was significant in case of total potassium. [ABSTRACT FROM AUTHOR]

Appropriate agronomic management is vital for the soil fertility and crop output of coastal salt-affected farmlands. Cattle manure incorporation and straw mulching are targeted as effective methods that can improve soil structure and stimulate crop growth, respectively. However, the combined application of manure and straw into salt-affected soils is less documented, especially with limited water supplement. In this study, a 3-year field experiment (2016–2018) was conducted in Binhai district, Tianjin, China to evaluate the effects of traditional tillage without manure and straw mulching application (TT), cattle manure incorporation (CM), straw mulching (SM), and CM combined with SM (CM + SM) on soil physiochemical properties, maize (Zea mays L.) growth, and water use efficiency. TT represented traditional cultivation in the study area without manure and straw application, as a control. All four treatments were carried out in a randomized block design with three replicates. The results demonstrate that CM treatment relieved salinity, decrease bulk density, and thereby stimulated root development. SM also has the advantage of improving salinity via 3-year implementation. Throughout the 3-year cultivation, CM + SM crop yields increased by >14.3% and grain water use index (GWUI) improved by >14.7% in comparison to TT treatment due to the improvement in soil properties. These benefits in soil properties, crop yield, and water use are important for minimizing salt constraints and realizing regional agro-ecological values.

The pace of land degradation has almost doubled across the Western Ghats of India, one of the world's 'hotspots' for biodiversity, owing to soil erosion, mining, and rampant urbanization. The arising nutrient depletion leading to land degradation is thus a serious threat to agricultural sustainability in this region. Delineation of spatial soil property maps for nutrient management is an effective strategy for precision agriculture. The present investigation was carried out in North Goa District in Western Ghats, a seldom researched domain in the Indian coastal region. The study involved spatial array analysis of soil properties of 383 georeferenced soil samples and used fuzzy k‐means clustering for delineation of management zones (MZs). Soils were found highly acidic with low available N, P, and medium exchangeable K with a widespread Zn, Cu, and Fe deficiency and sporadic salinity. Soil properties exhibited low to high levels of skewness except for soil pH and Mn. Correlations between soil pH and K, Zn, and Mn, between EC and Fe, between soil organic carbon (SOC) and N, P, K, Cu, and Mn was positive and significant (P = 0.01). Geostatistical analysis revealed varied distribution pattern for soil properties with Gaussian (pH, P, and Cu), spherical (EC), stable (SOC), hole effect (N), K‐Bessel (K and Fe), exponential (Zn), and circular (Mn) as best fit semivariogram models with weak and strong spatial dependence. The spatial variability was mapped, and two MZs were delineated. The developed maps will be crucial in site‐specific nutrient management for agricultural and ecological sustainability in the Western Ghats of India. [ABSTRACT FROM AUTHOR]

Microplastics (<5 mm) are considered to be emerging pollutants of global concern. Investigations on microplastics pollution in coastal and marine environments have increased recently but knowledge gaps still exist regarding microplastics in coastal beach soils with high-intensity human activities. In the present study a total of 120 soil samples were taken from 53 sites along >3000 km of coastline in Shandong province, east China, adjacent to both the Bohai Sea and the Yellow Sea coastlines under different land use management. Microplastics were separated from the soil samples using a continuous flow and floating separation apparatus. The shape type, size, abundance, spatial distribution, polymer composition and surface morphology of the microplastics were identified by a range of advanced microscopic and micro-analytical methods. The analytical results show that seven shape types, namely foams, pellets, fragments, flakes, fibers, films and sponges, were present in the beach soils. The polymer composition of the microplastics included polyethylene, polypropylene, polystyrene, polyether urethane and a polymer blend of both polyethylene and polypropylene. Approximately 60% of the observed microplastics had a size range < 1 mm. Microplastic abundance varied greatly among the soils, ranging from 1.3 to 14,712.5 N kg −1 (dry weight) as influenced by high-intensity human activities such as mariculture, tourism, and port construction. The seven shape types of microplastics from the coastal environment had different weathering surface morphologies, showing scratches, creases, micropores, cracks, either concave or convex, and of various shapes and sizes, possibly due to physical friction, photochemical oxidation and/or animal attack. Algae or crude oil was observed on the surface of some microplastics. The weathered surfaces of microplastics might act as a high-capacity carrier with adhering microorganisms and chemicals. Further studies are required on the weathering processes, sorption capacity and transport of microplastics especially in smaller size (<1 mm) under coastal conditions. [ABSTRACT FROM AUTHOR]

Amorphous silica accumulation in grasses is widely described in numerous species; however, work done in relation to the factors affecting this accumulation in the tissues and different type of cells, is still incipient. Here, we analysed a perennial tussock grass, Cortaderia selloana (Schult. & Schult.f.) Asch. & Graebn. (Pampas grass), a native and widely spread species from South America, which is also considered an invasive plant in many regions of the world. We analysed the relation between silicification process, soil type and environment, and anatomical features. Silicophytolith content and distribution in plants was analysed through calcination and staining techniques and SEM-EDAX analyses. Silicophytolith content was higher in leaves (2.48-5.54% DW) than in culms (0.29-0.43% DW) and values were similar to other tussock grasses. A relationship between the habit of a grass species and the potential maximum content of amorphous silica is suggested. Plants grown in soils from modified environments with high silica content (Anthrosol and Tecnosol) produced a higher content of amorphous silica. In leaves, the distribution of silicified cells was conditioned by leaf xeromorphic features. Soil Si content and environmental conditions (radiation, disturbance) are more relevant in silicification process than phenological factors. Within leaves, the accumulation of amorphous silica is conditioned by anatomy and transpiration. [ABSTRACT FROM AUTHOR]

Persistent scatterer interferometry (PSI) provides a new perspective to monitor the movements of coastal structures due to long-term consolidation using satellite-borne remote sensors. The method has the advantages of detecting the displacements at a very high spatial (from 1 to a few meters) and temporal (from 10 to 30 days) resolution. Cost-effective monitoring of complex and large (some kilometer long) structures can be done over long time (up to 10 years) intervals and at large scales (tens times tens km) of investigation. Here, these measurements are integrated with geotechnical, site-specific measurements to characterize in a unique framework the long-term compressibility of coastal soils over large areas. The approach is tested on the 60-km-long coastland of the Venice Lagoon, Italy. An accurate quantification of the movements of coastal infrastructures at the Venice coastland is carried out by PSI using ENVISAT ASAR and TerraSAR-X images acquired from April 2003 to December 2009 and from March 2008 to January 2009, respectively. Several nearshore and offshore structures were constructed over the decades to protect Venice and its coastal environment from sea storms and high tides. Long jetties were built at the lagoon inlets since the end of the 18th century, significantly reinforced between 1994 and 1997, and finally reshaped since 2003 in the framework of the MOSE construction (i.e., the project of mobile barriers for the temporarily closure of the lagoon to the sea). The measured displacements range from a few mm/year for the structures older than 10 years to 50-70 mm/year for those realized a few years ago. The PSI measurements are combined with the outcome of a detailed geomechanical characterization of the lagoon subsoil obtained by a field-scale experiment started at the end of 2002 and monitored to 2008. The use of the stress-strain properties derived from the trial embankment and the actual lithostratigraphy below the coastal structures, which is available from several piezocone profiles and boreholes, allows for the computation of secondary compression (consolidation) rates that match very well the PSI-derived movements. The results provide important information on the potential of using PSI to characterizing geotechnical properties (magnitude and distribution) of coastal deposits, as well as to estimate the expected time-dependent geomechanical response of coastal structures or other large constructions. [ABSTRACT FROM AUTHOR]

Capacity of a wetland to remove nitrate through denitrification is controlled by its physico-chemical and biological characteristics. Understanding these characteristics will help better to guide beneficial use of wetlands in processing nitrate. This study was conducted to determine the relationship between soil organic carbon (SOC) quality and denitrification rate in Louisiana coastal wetlands. Composite soil samples of different depths were collected from three different wetlands along a salinity gradient, namely, bottomland forest swamp (FS), freshwater marsh (FM), and saline marsh (SM) located in the Barataria Basin estuary. Potential denitrification rate (PDR) was measured by acetylene inhibition method and distribution of carbon (C) moieties in organic C was determined by 13C solid-state NMR. Of the three wetlands, the FM soil profile exhibited the highest PDR on both unit weight and unit volume basis as compared to FS and SM. The FM also tended to yield higher amount of N2O as compared to the FS and SM especially at earlier stages of denitrification, suggesting incomplete reduction of NO3 − at FM and potential for emission of N2O. Saline marsh soil profile had the lowest PDR on the unit volume basis. Increasing incubation concentration from 2 to 10 mg NO3 −-N L−1 increased PDR by 2 to 6 fold with the highest increase in the top horizons of FS and SM soils. Regression analysis showed that across these three wetland systems, organic C has significant effect in regulating PDR. Of the compositional C moieties, polysaccharides positively influenced denitrification rate whereas phenolics (likely phenolic adehydes and ketonics) negatively affected denitrification rate in these wetland soils. These results could have significant implication in integrated assessment and management of wetlands for treating nutrient-rich biosolids and wastewaters, non-point source agricultural runoff, and nitrate found in the diverted Mississippi River water used for coastal restoration. [Copyright &y& Elsevier]

Appropriate agronomic management is vital for the soil fertility and crop output of coastal salt-affected farmlands. Cattle manure incorporation and straw mulching are targeted as effective methods that can improve soil structure and stimulate crop growth, respectively. However, the combined application of manure and straw into salt-affected soils is less documented, especially with limited water supplement. In this study, a 3-year field experiment (2016–2018) was conducted in Binhai district, Tianjin, China to evaluate the effects of traditional tillage without manure and straw mulching application (TT), cattle manure incorporation (CM), straw mulching (SM), and CM combined with SM (CM + SM) on soil physiochemical properties, maize (Zea mays L.) growth, and water use efficiency. TT represented traditional cultivation in the study area without manure and straw application, as a control. All four treatments were carried out in a randomized block design with three replicates. The results demonstrate that CM treatment relieved salinity, decrease bulk density, and thereby stimulated root development. SM also has the advantage of improving salinity via 3-year implementation. Throughout the 3-year cultivation, CM + SM crop yields increased by >14.3% and grain water use index (GWUI) improved by >14.7% in comparison to TT treatment due to the improvement in soil properties. These benefits in soil properties, crop yield, and water use are important for minimizing salt constraints and realizing regional agro-ecological values. [ABSTRACT FROM AUTHOR]

In the European coastal dunes, marram grass ( Ammophila arenaria) is planted in order to control sand erosion. In the years 1986 to 1991, workers on the Wadden islands in the Netherlands planting marram grass showed lesions of skin and mucous membranes, suggesting a toxic reaction. Fusarium culmorum dominated the mycoflora of those marram grass culms that were used for planting. This plant material had been cut and stored for more than one week in the open. The Fusarium toxin deoxynivalenol (DON) was detected in the suspect marram grass culms. Isolated F. culmorum strains were able to produce DON in vitro in liquid culture as well as in experimentally inoculated wheat heads. Pathogenicity tests, toxin test as well as RAPD analysis showed that the F. culmorum strains were not specialized for marram grass but may form part of the West-European F. culmorum population infecting cereals and grasses. Storage on old sand-dunes with plant debris may have led to the high occurrence of F. culmorum and contamination with DON. Marram grass culms should be obtained from young plantings on dunes on the seaward slopes and cut culms should not be stored. [ABSTRACT FROM AUTHOR]

• Morphology data of 468 coastal soil profiles was explored to assess soil quality. • A minimum data set (MDS) of soil morphological quality indicators was identified. • Morphological soil quality index (MSQI) was derived from categorical variables. • Land-use type significantly affected MDS and MSQI. • Coastal rice-growing soils were poor in quality due to structural degradation. Soil quality in coastal agroecosystems changes rapidly owing to coastal dynamics and land-use change. The potential of soil morphological properties as soil quality indicators is mostly unexplored. We present a minimum data set (MDS) of soil morphological properties to quantify the coastal soil quality. We compiled a dataset including 18 soil morphological properties from 468 soil profiles, representing five land-use types (plantation crops, sugarcane, grassland, rice, and cotton + pigeon pea) of the north-western coastal region of India. The categorical variables were transformed into numerical variables using the optimal scaling method, and categorical principal component analysis (CATPCA) was used to identify the MDS. The CATPCA produced five principal components explaining 60% of the variability. The MDS comprises pore abundance, structure size, drainage, pore size, and colour (value) with 32, 22, 21, 14, and 12% contribution to soil quality, respectively. The morphological soil quality index (MSQI) varied from 0.26 to 0.99 for surface soils, and from 0.11 to 0.94 for the subsurface soils. Among the land-use types, the rice-growing soils were low in their morphological quality due to structural degradation. Land-use types significantly influenced the MSQI in both surface and subsurface soils, and hence, we recommend the inclusion of subsurface soils for soil quality evaluation. The strong relationship of MSQI with saturated hydraulic conductivity (R2 = 0.56) validated the suitability of the MDS for assessment of soil quality by the farmers, and non-experts in the coastal regions. Further, the higher variability explained by the soil morphology data indicates that the MDS identified in this study could be effectively used to evaluate soil quality in areas with limited data. [ABSTRACT FROM AUTHOR]