Shallow Ditches Research Articles

Lethal grip for an endangered endemic frog: The freshwater crab Potamon karpathos (Decapoda, Potamidae) preys on Karpathos water frog Pelophylax cerigensis (Anura, Ranidae)

Invertebrate predation on amphibians is widespread, although unreported in Europe. Here, we present documented predation of the Karpathos water frog (Pelophylax cerigensis) by the crab Potamon karpathos. Pelophylax cerigensis is an endangered, endemic species exclusively found on the Rhodes and Karpathos Islands in the South Aegean Sea, Greece. The Karpathos population is at risk due to limited suitable habitats and a scarcity of freshwater bodies on the island. From April to October, when there is no rain on the island, frogs and crabs cohabitate, sharing the same shallow ditches. Incidents of frog predation by crabs are common, indicated by numerous individuals with amputated limbs and scars, representing an additional threat to the endangered frog. Further research on the interactions between the two species is urgently required, as it has direct conservation implications.

Potential of solar photodegradation of antibiotics in shallow ditches: Kinetics, the role of dissolved organic matter and prediction models

Shallow ditches, which generally receive livestock or domestic sewage, are widely distributed in rural and suburban areas, making them important sites for antibiotic exposure. Because of the easy penetration of solar irradiation, the photochemical reactions of antibiotics tend to be active in shallow ditches. This study investigated the photodegradation potential of 21 commonly used antibiotics belonging to five categories in a typical shallow ditch by conducting simulated solar irradiation experiments. The influence of dissolved organic matter (DOM) in ditch water on the photodegradation of antibiotics was analyzed, and a model based on DOM changes was established to predict the degradation behavior of antibiotics. The results indicated that the degradation rates of different varieties of antibiotics in ultrapure water and ditch water followed the trend of fluoroquinolones > tetracyclines > sulfonamides > macrolides > lincosamides. In ditch water, direct photodegradation and photooxidation mediated by 3DOM∗ played predominant roles in the antibiotic photodegradation, whereas the contributions of singlet oxygen (1O2) and hydroxyl radicals (·OH) varied significantly depending on the reactivity of the antibiotics. A simple and effective model was proposed for predicting the photodegradation process of antibiotics in ditch water based on the degree of DOM photobleaching determined by excitation-emission matrix fluorescence spectroscopy coupled with parallel factor analysis. The prediction model was simplified by considering the similarity in photochemical properties within the same category of antibiotics and was validated by field tests. This study fills a critical research gap by evaluating the photodegradation of antibiotics in shallow ditches, thereby providing valuable insights into their fate and transport in shallow ditch water.

Performance of surface, subsurface and trench‐type drainage systems in paddy fields for non‐rice farming

AbstractEffective drainage is a crucial factor in paddy fields, especially in regions with waterlogging or heavy clay soils. Identifying an effective drainage system is essential for the successful removal of excess soil water from paddy fields to prepare them for subsequent crops. This study aimed to evaluate three different drainage systems, shallow surface drainage (shallow ditch), conventional subsurface pipe drainage and trench‐type subsurface drainage (French drain), in paddy fields in terms of drainage water volume, water table depth, drainage intensity, soil moisture and cracks. Experiments were carried out in a physical model capable of simulation with a 7.5 m drain spacing. The findings indicated that trench‐type drainage was more effective in reducing soil moisture due to its higher drainage water volume compared to other systems. The time required for the topsoil to reach its lower plastic limit in the subsurface, trench‐type and shallow surface drainage systems was 14, 11 and 15 h after the depletion of excess water over the soil surface, respectively. Although shallow surface drainage represented faster depletion of excess water, trench‐type drainage eventually proved to be the most effective alternative for providing appropriate qualifications for secondary cultivation. Crack areas on the soil surface were twice as extensive in trench‐type and subsurface drainage systems as in shallow surface drainage systems, indicating their superior performance.

Effects of Shallow Surface Drainage Ditches With Controlled Subsurface Drainage Management on Crop Yields in North Carolina

Highlights Shallow surface ditches with controlled subsurface drainage (SD) increased corn and soybean yields in eight of nine growing seasons compared to conventional drainage. The SD system increased corn yields on average by 0.4 Mg/ha, or 4% (0.7 Mg/ha, or 6.6%, excluding 2016). The SD system increased soybean yields on average by 0.5 Mg/ha, or 14.3%. Abstract. Agricultural drainage in the coastal areas of North Carolina (NC) is commonly achieved through large trapezoidal-shaped ditches. The coastal region of NC has limited topographic relief (slopes < 1%) with poorly drained soils that can cause substantial issues with surface water ponding during high-intensity or long-duration precipitation events without some form of surface drainage. Installation of large free flowing surface ditches (FD) with field crowning improves the drainage intensity but can create negative consequences such as over drainage and side slope scouring within the ditch. Large open ditches remove tillable land from production and serve as a primary transport pathway for pollutants. An alternative drainage design (SD) has been implemented that decreases the size of the surface ditches, limiting their drainage effect to only surface water and potentially improving equipment trafficability. The smaller ditches, installed with precision grade equipment, are placed on a grade sufficient to direct surface flow while keeping soil movement to a minimum. Lateral subsurface drainage tiles are installed to provide subsurface drainage and are connected to a main tile line operated with an outlet control structure for controlled drainage (CD). This study evaluates the crop yield and water table effects of the SD system compared to FD over nine crop seasons from 2014-2022. The SD treatment increased yield in eight of the nine crop seasons overall, four of five corn (Zea mays L.) crops, and all four soybean (Glycine max L.) crops. Overall, SD increased corn yields by 0.4 Mg/ha or 4% (0.7 Mg/ha or 6.6% with the exclusion of 2016) and soybean yields by 0.5 Mg/ha (14.3%). The effects of SD on crop yield and water table show that the system can be utilized to improve crop health and provide better management of cropland for producers. Keywords: Corn Yield, Drainage Water Management, Soybean Yield, Surface Drainage, Water Table.

Dwellings of the population of the Early Iron Age Baitovo Culture in the Tobol-Ishim forest-steppe

In this paper, the results of the study of dwellings of the Baitovo Culture population of the Early Iron Age in the Tobol-Ishim forest-steppe are presented. The research was aimed at identification of types of dwellings pre-vailing among the Baitovo population, analysis of their structural features and graphical reconstruction of two structures: a surface dwelling from the settlement of Dachnoe 1 and a half-dugout from the settlement of Lake Chencher 6. In total, 42 Baitovo dwellings studied by excavations were analyzed. Investigation of the sites by small areas does not permit characterization of the building system of the Baitovo settlements. Location of the dwellings on sandy soils, surface character of the buildings and rebuilding resulted in that not always it is possible to identify the edge of the ditch or the contour of the building. Due to these circumstances, it is possible to make general observations on the structure of dwellings, although reconstruction of certain detached buildings is com-plicated. The procedures used in reconstructing the dwellings are based upon the analysis of the position of the remains of the structure within the planigraphy and stratigraphy of excavation areas. Identification of basic ele-ments of the building frame is based upon the analysis of mutual spatial arrangement of the post pits, building ditches etc. For the reconstruction of the exterior of the structures, the method of constrained reconstructions was employed, which allows identification of the object exterior and analysis of its possible variants. The classification of the 42 Baitovo dwellings showed that they are represented evenly by two types: half-dugout (21 structures) and surface (21 structures) structures. The surface structures of a subrectangular shape, with a shallow ditch in the center and without it, are enclosed within grooves or barrow pits. Among the dwellings sinking into the ground, two groups stand out — buried insignificantly in the subsoil for up to 10–20 cm and half-dugouts sunk into the subsoil for more than 25 cm. Altogether, two structural types of dwellings were identified in the Baitovo house-building: framed buildings (surface and buried into the ground) and dwellings with walls built in a log-crib tech-nique. Therefore, the appearance of a new type of dwellings in the Baitovo housebuilding has been identified — the log-crib buildings, as well as the traditions of buildings sinking into the ground. Most likely, this is due to the influence of the housebuilding traditions of the Gorokhovo (sinking buildings, appearance of long corridor-exits or passages) and Itkul (surface framed dwellings) Cultures.

Cracking behavior of sisal fiber-reinforced clayey soil under wetting-drying cycles

Climate variables such as rainfall and high temperature can influence clayey soil moisture and the development of cracks, which can further give rise to environmental and geological disasters. This study investigates the influence of different soil thicknesses, fiber content, and three wetting-drying cycles on soil moisture evaporation and the formation and development of cracks. A photographing system and weighing equipment are used to track the changes in soil mass and cracks during three wetting-drying cycles. Resulting photos of the cracks are quantified and analyzed by image processing technology. Results show that the thicker soil layer can prolong the normal evaporation phase and reduce the stress concentration on the surface, resulting in a delay in cracking. However, this could lead to the development of wide cracks and the formation of shallow ditches, which is an irreversible process with multiple wetting-drying cycles. Sisal fibers are able to effectively solve the aforementioned problems in terms of, reducing the development of longitudinal and lateral cracks and shallow ditches. This further reduces the rate of sudden cracking and helps to maintain the soil’s structural integrity. The healing ability of wetting-drying cycles for cracks increases with the sisal fiber content. These findings indicate that soil cracking is influenced by many factors, though there are no absolute factors that promote or hinder the development of cracks. Therefore, methods that can amplify the positive effects while weakening the negative effects should be explored.

ASSESSMENT OF SOIL MOISTURE AND NUTRIENTS ON TERRACE SLOPE OF HARD-SETTING SOILS IN SEMI-ARID EASTERN KEN

<p><strong>Background:</strong> Terraces are structures consisting of ditches and embankments used to control erosion and increase land productivity. There is, however, little emphasis on the effects of the ditch dimensions on soil moisture and nutrient dynamics. <strong>Objective:</strong> To determine the effect of varying ditch depths on soil moisture and nutrient quantities and their variability within the terrace slope on hard-setting soils. <strong>Methodology:</strong> Soil samples were collected seasonally in 2014 and 2015 from terraces with different ditch depths (60, 30, and 0 [control] cm) for the determination of soil moisture content (SMC). The samples were collected from the upper, middle and lower slope positions of each terrace. Soil from the three slope positions of each terrace was also sampled at the end of the study and analyzed for total nitrogen (%TN), available phosphorous (Av. P), exchangeable potassium (K<sup>+</sup>) and % organic carbon (OC) contents. Data were subjected to a two-way analysis of variance and differences in means determined at a 95% level of confidence. <strong>Results:</strong> Significant interactions (P<0.001) in SMC were observed between seasons, ditch depths and slope positions. Higher SMC was found in treatments with 30 and 60 cm ditch depths in all the slope positions and seasons compared to the control. Soil moisture contents in the lower and upper slope positions were significantly different between the terraces with 30 and 60 cm ditch depths when rainfall was high and evenly distributed, but non-significant in poorly distributed rainfall seasons. Significant differences (P ≤ 0.05) in contents of total nitrogen and available phosphorous were found between the upper and lower slope positions of the terraces with ditches. <strong>Implications: </strong>The effect of ditch depths on moisture, total nitrogen and available phosphorous contents and their variability within the slope depended on the amount and distribution of rainfall. <strong>Conclusion: </strong>Construction of terraces with shallow ditch depths (of 30 cm) is recommended to conserve soil moisture and nutrients nitrogen and phosphorous on hard-setting soils in the marginal areas of semi-arid Eastern Kenya. </p>

Effects of Drainage on Greenhouse Gas Emissions and Yields of Lowland Rice—Wheat Rotation System in East China

The subtropical region of East China is characterized by abundant water and temperature resources conducive to crop cultivation, and large areas of lowland have been widely used for agricultural planting. The objectives of the study were to explore feasible methods of greenhouse gas (GHG) reduction for rice–wheat rotation systems and to explain the mechanism underlying the effect of drainage on GHG reduction. Shallow ditch (SD) and deep ditch (DD) treatments in the wheat season were set up for drainage to control the paddy soil water content, with conventional non-ditching as the control group (CG). CH4 and N2O emission fluxes were continuously measured, and related soil physical and chemical properties were also measured in this study. The results showed that CH4 emissions from paddy soil accounted for most of the global warming potential (GWP) in the rice–wheat rotation system. Drainage led to a significant reduction in cumulative soil CH4 emissions during the rice and wheat seasons; however, the overall cumulative N2O flux increased significantly. The total GWP produced by SD and DD in the three years was reduced by 58.21% and 54.87%, respectively. The GHG emission intensity (GHGI) of SD and DD declined by 60.13% and 56.40%, respectively. The CH4 emission flux was significantly positively correlated with the 5 cm ground temperature but negatively correlated with the soil redox potential (soil Eh). The drainage decreased the soil water and soil organic matter contents and increased soil pH, which were the mechanisms that reduced the CH4 emissions. The drainage increased the soil nitrogen content, which is the main reason for regulating N2O. The findings indicate that SD and DD not only ensured a stable increase in production but also effectively reduced GHG emissions, and we recommend SD treatment for agricultural production.

EDEM Simulation Study on the Performance of a Mechanized Ditching Device for Codonopsis Planting

Codonopsis pilosula is cultivated mainly in sandy soils, especially in the Dingxi area of the Gansu province, northwest China. They are mainly planted in hilly areas, where large machines cannot reach easily. Codonopsis pilosula transplanting has been adopted with a conventional flat planting way, film mulching and seedling outcrops. While its planting requires opening a shallow ditch, short operation cycle, considerable labor intensity and is in large demand, a simulation analysis was performed according to specific tillage resistance, helpful in the optimization design in later stages and the improvement of a domestic ditching plow’s performance. This paper studies the simulation performance of an adjustable trench plough and analyzes the orthogonal test and Design-Expert response surface of the data. EDEM simulation software was used to analyze the traction resistance of the furrow ditching mechanism in the ditching process. The results show that the traction resistance increased from 1751.31 N to 2197.31 N as the simulation working speed increased from 0.9 m/s to 1.5 m/s, 1.25 times higher than the former. It indicates that speed had significant effects on traction resistance. With the increase in working speed, the furrow traction resistance and specific consumed power were increased considerably. Using the stability coefficient of the ditching depth and consistency coefficient of ditching bottom width as test indices, speed and angle of furrowing as impact factors, Box–Behnken orthogonal experiment design method, and establishing test indices and test factors, the regression model between the analysis of the influence of the test index, comprehensive agronomic requirements and MATLAB factor optimization of the experiment, the optimized operation parameter combination was obtained: the forward speed was 0.9 m/s, the angle of ditching was 35° and the stability coefficient of the ditching depth and consistency coefficient of ditch bottom width were 97.57% and 98.03%, respectively. The data after the simulation comparison test can provide a design reference for the domestic small trench operation.

Realistic simulation of hydraulic erosion on slope

AbstractHydraulic erosion plays an important role in the formation of landform. Influenced by runoff, soil is destroyed, denuded, and transported to form a specific landform. The simulation of erosion can not only be used for the construction of realistic terrain, but also for evaluation in soil and water conservation, which has important research and application value. We construct a hydraulic erosion simulation framework on the basis of soil and water conservation's theory, which considers various factors in erosion, including: water flow, infiltration, transportation, erosion, ditch widening, deposition, and soil sliding. It is the first time to consider the generation time of runoff, soil fixation of plant roots, and ditch widening phenomenon in simulation. Using this method, we can simulate ditch evolution process from rill, shallow ditch, cut ditch to gully, which consist with the real process. Compared with real photos and data, our method has authenticity in both visual and theoretical aspects.

Field test of the TOXSWA pesticide fate model: Comparison of simulated and observed chlorpyrifos in water, sediment and macrophytes in four stagnant ditches

TOXSWA is a numerical model describing pesticide behavior in an edge-of-field waterbody. It is widely used to predict exposure in regulatory risk assessment for aquatic ecosystems. Exposure concentrations are predicted based upon pesticide process parameters obtained in standardized laboratory experiments. However, few tests of the model performance based on field data have been carried out. We compare simulated concentrations to observations from a field experiment with four shallow stagnant ditches over sprayed with chlorpyrifos, a moderately volatile pesticide with a significant sorption capacity. Input parameters describing the four ditches, such as dimensions, water depth, sediment and macrophyte characteristics were measured in detail. Additionally, laboratory experiments were carried out to determine site-specific values for parameters describing chlorpyrifos degradation in water and sediment, as well as sorption to the two dominant macrophyte species. Based upon these estimated parameters, the correspondence between simulated and measured concentrations in water, sediment and macrophytes is poor. We attribute this discrepancy to a lack of site-specific input for the processes of volatilization and sorption to sediment, which both are important processes for chlorpyrifos. Therefore, we calibrated TOXSWA using the optimization tool PEST. The transfer coefficient for volatilization and the coefficient for sorption to sediment were optimized based on the observed concentrations in water and sediment. This resulted in a substantial improvement of correspondence. Optimized values of the transfer coefficient for volatilization and the coefficient for sorption to sediment are substantially higher than their initial estimates (4–8-fold and 2–4-fold increase, respectively), but can be well explained. The optimized coefficients vary less than a factor 2 between the four ditches. We conclude that TOXSWA can adequately predict chlorpyrifos behavior in the four ditches, provided that reliable site-specific parameter estimates are available. Field tests for other pesticides, waterbodies and agro-environmental conditions are warranted.

Natural conditions of the formation of the monument of Maly Gonbinsky Kordon-2 of the Odintsovo Culture of Altai in the 4th–8th centuries A.D.

The study is aimed at reconstructing the natural and climatic conditions of the Upper Ob River region (south of Western Siberia) in the early Middle Ages (4th–8th centuries A.D.), based on the paleosol data obtained from the fortified settlements of Maly Gonbinsky Kordon-2/11 and Maly Gonbinsky Kordon-2 / 6-3. Settlements are located on the terrace of the right bank of the Ob River. The fortification elements are represented by a horse-shoe-shaped system of a ditch and a rampart, adjacent to the edge of the above-floodplain terrace, inside which there were dwellings and outbuildings. Archaeological investigations of the settlements permitted to study the sediments of the first terrace above the floodplain and to select core samples for palynological analysis. Applica-tion of this method allowed reconstruction of the vegetation during the occupational period of the complex of monuments MGK-2. For interpreting of the actual data, the method of landscape analysis was employed. The need for its application for carrying out paleogeographic reconstructions is warranted by the presence of the relict elements in the morphological structure of the landscapes. To establish their paleogeographic status, within the framework of this study, there was determined the percentage ratio of the amount of pollen and seeds of plants extracted from the deposits of the first above-floodplain terrace, corresponding to the existence of the Odintsovo Culture and belonging to different ecological groups. As the result, the dominance of sparse birch forests and forb dry meadows in the landscape structure of that time was established, whereas the vegetation associations featu-ring pine forests were in the status of progressive elements of the landscape structure. Also, supersedence of birch forb forests by green moss pine forests was revealed. The use of the landscape approach allowed recon-struction of natural conditions of the territory occupied by the complex of fortified settlements of MGK-2. On the basis of the digital elevation model, 3D visualization of the surface of the sediments overlapping the cultural layer of the monuments was rendered, which shows the location of the objects at the lowest elevations of the surface I above the floodplain terrace and the effects of the surface water flow. This necessitated construction of a drai-nage system, the main elements of which might be represented by shallow ditches.

Drainage and Stand Growth Response in Peatland Forests—Description, Testing, and Application of Mechanistic Peatland Simulator SUSI

Drainage is an essential prerequisite in peatland forest management, which generally, but not always, increases stand growth. Growth response depends on weather conditions, stand and site characteristics, management and biogeochemical processes. We constructed a SUSI-simulator (SUoSImulaattori, in Finnish), which describes hydrology, stand growth and nutrient availability under different management, site types and weather conditions. In the model development and sensitivity analysis, we used water table (WT) and stand growth data from 11 Scots pine stands. The simulator was validated against a larger dataset collected from boreal drained peatlands in Finland. In validation, SUSI was shown to predict WT and stand growth well. Stand growth was mainly limited by inadequate potassium supply, and in Sphagnum peats by low oxygen availability. Model application was demonstrated for ditch network maintenance (DNM) by comparing stand growth with shallow (−0.3 m) and deep ditches (−0.9 m): The growth responses varied between 0.5 and 3.5 m3 ha−1 in five years, which is comparable to experimental results. SUSI can promote sustainable peatland management and help in avoiding unnecessary drainage operations and associated environmental effects, such as increased carbon emissions, peat subsidence, and nutrient leaching. The source code is publicly available, and the modular structure allows model extension to cost–benefit analyses and nutrient export to water courses.

Characterizing spatially variable water table depths in a disturbed Zoige peatland watershed

Understanding spatial variability of water table depth (WTD) in larger peatland area is crucial for peat conservation. This study investigated spatial patterns of WTDs in a peatland watershed of about 0.151 km2, located in the Zoige basin of the Qinghai-Tibet Plateau, China. Using conventional dipwells, we measured WTDs on 5/17/2017, 5/20/2017, 5/23/2017, 7/17/2017, and 9/18/2017 at 114, 103, 105, 77, and 81 locations, as well as peat depths (H) and elevations at 119 and 831 locations over the watershed, respectively. Then, we performed hotspot analysis and Geographically Weighted Regression (GWR) modeling, showing (1) highly localized spatial patterns of WTDs, H, and S (slope gradient, calculated from elevations), and (2) the area that had statistically significant local coefficients for H ranged between 51 and 57% of the total watershed area, while that for S was only <11%. These complex spatial patterns of WTDs were further illustrated by our results of examining WTD changes in the lateral and longitudinal directions for two types of channels, deep gullies whose beds are deep and cut through the peat layer and shallow artificial ditches. The findings suggested that spatial and temporal changes of WTDs at the watershed scale may only be examined by collecting in situ samples, which may be achieved using an efficient sampling method provided in this study.

Soil stoichiometry of Pinus massoniana forest in red soil erosion area under different management patterns

We investigated the concentrations of carbon (C), nitrogen (N), and phosphorus (P) and C:N:P stoichiometry in soil and litter of Pinus massoniana forest under four different management patterns: inefficient forest transformation, mixture of arbor with shrub and herb, shallow ditch grass planting, and being banned in serious erosion and degradation of red soil in southern China. Our findings could provide scientific basis for soil erosion control and vegetation restoration in this area. The results showed that there were significant differences in soil organic carbon (SOC), TN, TP and litter nutrient content among different management patterns. The nutrient contents in soil and litter under all the four management patterns were significantly higher than that of control, with mixture of arbor with shrub and herb having the highest concentrations. The concentrations of SOC, TN and TP decreased with the increases of soil layer. However, the shallow ditch grass planting mana-gement pattern presented as follows: the concentrations of SOC, TN and TP decreased first and then increased with the increases of soil layer, with the lowest value in 5-20 cm soil layer. There were significant differences in soil C:N, C:P, N:P and litter C:P among different management patterns, and the soil spatial variation was C:N>C:P>N:P. Excepted for mixture of arbor with shrub and herb, C:N was still at a lower level in the other management patterns, and soil C:P and N:P showed higher values overall. Litter C:N, C:P and N:P had opposite change pattern, with inefficient forest transformation and mixture of arbor with shrub and herb being much smaller than the control. Soil C:N and C:P were mainly controlled by SOC content and litter C content, and soil N:P was mainly controlled by soil TP content and litter P content. Soil stoichiometry was affected by soil water content, soil bulk density, pH, and other factors. The relationship between litter and soil nutrients was closely related and showed similar changes.

Native and non-native frogs responded differently to modernization at Japanese paddy fields

Rice farming modernizations, especially changes in the irrigation system, have been accused as one of the reasons of frog population decline in Japan. Here, we examined responses of native frog, Daruma pond frog (Pelophylax porosus porosus) and non-native frog, Rice frog (Fejervarya kawamurai) population to the modernization in Japanese paddy field. We tested the following two hypotheses: 1) native frog’s density will be lower in the modernized paddy field, and 2) non-native frog density will not be affected by modernization. After two periods of field studies (2017 and 2018), we found that native frog’s density is indeed lower in modernized paddy fields, and the non-native frog’s density is lower in the non-modernized sites. Presumably, changes of shallow soil ditches to concrete ditches in modernized paddy fields act as a death trap for Daruma pond frog. Ditch depth and the distance from forest also significantly affecting the density of Daruma pond frog. On the other hand, the population of Rice frog did not show any negative response to the modernizations. The non-native frog population remained stable because they may have high fecundity.

Study on the intensified reduction of farmland non-point source pollution in winter using thermally insulated ecological shallow ditch

Ecological shallow ditch is one of the effective methods to improve non-point source pollution of farmlands. However, during winter when the temperature is low, the operation capacity of the common ecological shallow ditch (CESD) is not satisfactory. In the present study, a thermally insulated ecological shallow ditch (TESD) was constructed, and the pollutant removal efficiency of the two ecological shallow ditches (thermal-insulation type versus common type) was compared. The changes in the number of bacteria inside these two types of shallow ditches were studied, and the underlying mechanism was analysed. The results showed that the thermally insulated ecological shallow ditch could partly reduce the adverse effects of low temperature and keep the surface temperature above 10°C. After 18 days of observation in the winter, the removal rates of COD, TN and TP in the effluent were respectively 1.3 times, 2.5 times and 1.3 times higher than those of the common type, and the concentration of bacteria in each site was also higher for TESD. The oxygen content in the soil layer and filler layer in TESD increased. Moreover, TESD also demonstrated higher microbial activity and more active plant growth than the CESD.

The first Neolithic roundel discovered in Poland reinterpreted with the application of the geophysical Amplitude Data Comparison (ADC) method

AbstractThis article presents the results of a three‐dimensional (3D) stratigraphic analysis of a Neolithic roundel in Bodzów (south‐western Poland) with the application of the Amplitude Data Comparison (ADC) method. The ADC method is based on the comparison of magnetic amplitude records (in nanoteslas) with corresponding ground‐penetrating radar (GPR) reflection profiles. Thus, it is possible to analyse the 3D aspects of buried features based on GPR images and their composition from magnetic readings. In other words, the ADC method can be used to provide a more complete understanding of buried archaeological objects and structures detected by geophysical surveys using GPR and magnetic (gradiometer) methods. The surveys performed in Bodzów have indicated that the Neolithic roundel located there had a multiphase development and thus is perfectly suitable for a study with the application of the ADC method. The performed ADC analysis indicates that there were three gates leading to the roundel interior. Positions of prehistoric storage and dwelling pits, and other settlement features were also detected and interpreted. Clusters of these features are located both inside and outside the roundel, which suggests that people lived within the site during different periods. In the southern part of the roundel, GPR reflection profiles and associated magnetic readings point to the presence of V‐shaped shallow ditches, which may date back to the early Iron Age, as well as an extensive Pleistocene fluvial channel and associated geological features, which is very clearly marked on GPR maps.

Soil sedimentation and quality within the roadside ditches of an agricultural watershed

Roadside ditches are an integral component to the >6.3 million km of roadsides in the U.S. and act as drainageways for millions of hectares of watershed runoff. Our study of six roadside ditches in Lime Creek watershed characterized soil nutrients and heavy metal patterns as well as quantified the physical and hydrological properties of ditch soils. At all ditch sites, we identified significant sedimentation of silt-sized particles, total nitrogen, and soil carbon in shallow roadside ditch soils. A post-settlement surface soil horizon significantly higher in silt content was observed compared to the underlying subsoil and parent material. Although accumulation of several heavy metals was measured in ditch soils, significant variability was not observed within the ditch environment. Most of the heavy metal concentrations were found to be either similar to or lower than state-wide averages. Higher levels of calcium near the roads were likely due to annual use of road deicers. Overall, we estimated that 42 Mg/ha of total carbon and 5 Mg/ha of total nitrogen are being stored in agricultural ditch soils, which is similar to that of surrounding agricultural land in terms of total carbon storage, but much higher than estimates of total nitrogen storage. Our study of six roadside ditches in an eastern Iowa watershed documented the soil chemistry, morphology, and sediment accumulation that occurred since ditch construction. Further research is needed to develop a better understanding of how the soil and water conditions in the ditches related to the watershed areas that feed them.

ZOTINO III: AN EARLY IRON AGE METALLURGICAL CENTER IN THE TRANS-URALS

In 1974 and 1977, an archaeological expedition from the Ural State University excavated part (441 m2 ) of a fortifi ed Early Iron Age manufacturing site on the Bagaryak River near Zotino, in the forest zone of the Trans-Urals foothills. The site, measuring 80 m by 50–66 m (total area, 3800 m2 ), is located on a 40–43 m high cliff. Its northeastern inland side is protected by a low stone and earthen wall, preserved to the height of 0.75 m, and is delimited by a shallow outer drainage ditch. The single entrance is ~2 m wide. Under the wall, there is a thin layer of buried soil with fragments of the Itkul ceramics. Inside the wall, carbonaceous sandy loam, pieces of calx, and charred remains of wooden structures were found. Our reconstruction suggests that the original 2 m wide wall consisted of two rows of logs and a built-in square tower ~3.0 m by 2.6 m. The base of the walls and tower were strengthened with rubble, and its outer face was enforced with limestone slabs. Near the wall and along the northwestern edge of the site’s inner space, remains of three adobe platforms for processing copper and iron were identifi ed, two dug-in ovens, a utility pit and, apparently, remains of an adobe melting furnace. This is the easternmost and latest (400–100 BC) seasonal fortifi ed metallurgical center of Itkul—an autochthonous culture in the forest zone of the eastern Ural Mountains. In the forest-steppe east and south of it, on the lower reaches of the Sinara and Karabolka rivers, the westernmost fortresses built by the Gorokhovo herders (500–100 BC) are situated—the likely source of the Itkul fortifi cation tradition.