Paleosols buried under kurgans of the Pit-grave culture in the steppe zone of the Cis-Ural region

The analysis of soil chronosequences developed from loamy and loamy sandy substrates and buried under kurgans dating back to the Pit-grave archaeological culture in the steppe zone of the Cis-Ural region demonstrated that it is possible to trace the dynamics of the soil properties and to perform paleoclimatic reconstructions for different intervals within the studied period. The properties of sandy soils changed more rapidly than the properties of loamy soils. For sandy soils, notable changes in their properties were revealed in the soil chronosequences dating back to the particular stages of the Pit-grave culture; for loamy soils, such changes could only be traced for the soils buried under the kurgans dating back to different stages of the Pit-grave culture.     

Mobility of heavy metals in polluted soils near zinc smelters

The distribution and the availability of Cd, Zn, Cu, and Pb along the entire profile of two highly polluted soils located near Zn smelters have been related to the chemical and mineralogical composition of the soil. Lead and Cu deposits always remain in the surface layers and their availability measured by neutral ammonium acetate extraction was very weak. The behavior of Cd and Zn appears different in sandy acidic podzolic soils and in neutral loamy soils. These metals are associated with the organic matter migration in podzolic soils, while they remain in the upper layers in loamy soils provided that the pH is higher than 6. When the pH drops below 6, the mobility of Cd increases while that of Zn increases only below pH 5. The availability of heavy metals is lower in neutral loamy soils than in sandy acidic soils due to precipitation of carbonates and phosphates. With increasing depth, Cd and Zn are more available if the soil is acid; but, if the soil is neutral and loamy the availability is kept low by adsorption on clays and free oxides. The results of the complex trace metals interactions with the soil components show a higher accumulation capacity for loamy soils than for sandy soils notwithstanding the fact that their CEC is similar.     

Landau–Deryagin law and hydration energy of soils of different genesis

Linear regression equations between the logarithm of the total soil moisture potential and soil moisture content in the hygroscopic moisture range (Landau–Deryagin law) were derived for typical soils from different natural zones of European Russia. From these equations, a compact algorithm was developed for calculating the hydration energy of soils, which increases from 1280 to 10600 J/kg in the following soil series: heavy loamy soddy podzolic soil–heavy loamy gray forest soil–medium loamy light chestnut soil–heavy loamy brown semidesert soil–light clayey solonchak–light clayey chernozem–medium clayey krasnozem. Relationships were revealed between the hydration energy of soils, the specific surface of soils, the content of physical clay in soils, and the concentration of hydrated exchangeably adsorbed ions.     

Assessing the biological activity of oil-contaminated soddy-podzolic soils with different textures

The respiratory activity features in oil-contaminated soddy-podzolic soils of different textures have been studied. Unidirectional processes occur in contaminated loamy and loamy sandy soddy-podzolic soils; their intensities depend on the soil parameters. The mineralization rates of the oil products and the activity of the microflora in loamy soils exceed the corresponding parameters for loamy sandy soils. The long-term impact of oil and its transformation products results in more important disturbances of the microbial community in light soils. It has been shown that light soils containing 9% oil require longer time periods or more intensive remediation measures for the restoration of soil microbial cenoses disturbed by the pollutant.     

Mechanisms of potassium uptake efficiency and dynamics in the rhizosphere of safflower and sunflower in different soils

Potassium uptake efficiency of safflower and sunflower was studied under semi-controlled conditions in loamy and sandy soils. Both species performed better in loamy soil. Safflower had higher agronomic efficiency and higher relative root length under suboptimal K supply. Safflower had higher specific root density and less root radius at all K levels. Safflower had higher relative root-shoot ratio under suboptimal K in loamy soil. Both species had similar K-influx at low and optimal K in loamy soil, while sunflower had higher influx under suboptimal and optimal supplies in sandy soil. Safflower had higher shoot demand in both soils under suboptimal and optimal K. Both species depleted similar amounts of soil solution-K under suboptimal K in sandy soil, while sunflower was more efficient under suboptimal levels in loamy soils. Sunflower depleted more extractable-K under both suboptimal and optimal K. Safflower could be considered K-uptake efficient crop.     

不同类型的污泥对土壤微生物性质的影响: 地中海退化土的田间试验研究

The recycling of suitable organic wastes can enhance soil fertility via effects on soil physical, chemical and biological properties. To compare the effects of digested (DS), thermally dried (TDS) and composted dewatered (CDS) sewage sludge on soil microbiological properties, an experiment was conducted at field sites for more than one year (401 d) when applied to two Mediterranean degraded soils (loam and loamy sand soils). All three types of sewage sludge had a significant effect on measured parameters. I...     

Acidity Changes of Foreign Acidic Soils Introduced into Calcareous Soil Environment

Abstract

Many tropical plant species originated in areas with acidic soils and do not grow well in calcareous (high pH) soils. It is impossible to acidify soils that have high contents of calcium carbonate in south Florida. Replacing calcareous soils with acidic soils obtained from distant regions is an alternative. Unfortunately, such introduced acidic soils may eventually be neutralized by irrigation and ground water that is saturated with calcium carbonate. The objective of this investigation was to examine the acidity changes and buffering capacities of three types of acidic soils (silica sand soil, red loamy sand soil, and a mixed soil) used to establish tropical plants in a rainforest exhibition at Fairchild Tropical Garden, Miami, FL. The three areas were excavated to remove native calcareous soil, limestone bedrock, and filled with acidic soils. Various rainforest plants were planted. Soil samples were collected in contiguous 10 cm‐deep segments from the soil surface to the bedrock shortly after deposition of the soils and one year later. Soil pH, EC, particle distribution, buffering capacity were determined. Results showed that both silica sand and mixed soils had been neutralized and the soil pH values had risen over 7 in all soil depths after one year. However, less than 10 cm of the surface and bottom soil layers of red loamy sand had been neutralized and the soil pH in the middle of soil profile remained unchanged due to its higher buffering capacity. A column leaching study showed that the acidity in the red loamy sand soil would be neutralized by irrigation water and by capillary movement of groundwater with a high concentration of calcium bicarbonate. Buffering curves indicate that it is easier to maintain acidity in sandy soil than of loamy sand and mixed soils with acidified irrigation water. Indeed it is difficult to acidify the mixed soils with high organic matter content after these soils have been neutralized.     

菜园土壤锌的吸附——解吸特性研究

本文研究了菜园土壤锌的吸附 -解吸特性。实验结果表明 ,三种菜园土壤吸附Zn2 + 均随平衡液中Zn2 + 浓度的增加而增大 ,且均可用Langmuir方程和Freundlich方程来描述 ,相关系数均大于 0 .9,达极显著水平。由Langmuir方程求得的菜园土壤对Zn2 + 的最大吸附量的大小顺序为 :黄松土 >粉泥土 >江涂砂 ,但对Zn2 + 的吸附作用力强度和最大缓冲容量的顺序则相反 ,以江涂砂 >粉泥土 >黄松土。菜园土壤对Zn2 + 的解吸量随其吸附量的增加而增加 ,两者之间呈显著线性正相关。     

Effects of 'Agri-SC' soil conditioner on soil structure and erodibility: some further observations

Abstract. In field and laboratory experiments the conditioner‘Agri-SC’has shown improvements in the structure of loamy sand soils in east Shropshire, UK. It resulted in statistically significant decreases in soil bulk density values and increases in soil porosity and aggregate stability. Further experiments are in progress on both loamy sand and silt loam soils.     

DCD 在不同质地土壤上的硝化抑制效果和剂量效应研究

通过硝化抑制剂抑制土壤硝化作用是实现作物铵硝混合营养和提高氮肥利用率的重要途径之一。本试验采用室内模拟的方法, 在人工气候室(25 ℃)黑暗培养条件下, 应用新疆石灰性土壤研究了不同剂量的双氰胺(dicyandiamide, DCD)在砂土、壤土、黏土3 种不同质地土壤中对土壤硝态氮、铵态氮转化的影响及DCD 的剂量效应和硝化抑制效果。处理30 d 内, 各剂量DCD 处理对砂土的硝化抑制率为96.5%~99.4%(平均值为98.3%), 在黏土上为66.9%~85.6%(平均值为77.6%), 在壤土上为49.3%~79.4%(平均值为67.7%), 总体硝化抑制率表现为砂土>黏土>壤土。在砂土上DCD 的剂量效应不明显, DCD 用量从纯氮的1.0%增加到7.0%时, 土壤中硝态氮含量仅增加1.9~10.7 mg·kg^-1(培养30 d 时); 而在壤土和黏土中, 土壤硝态氮含量随DCD 浓度的增加而显著下降, 存在明显剂量效应。这说明施用DCD 可显著抑制新疆石灰性土壤的硝化作用过程, 在砂土、壤土、黏土中DCD 的最佳浓度分别为纯氮用量的6.0%、7.0%和7.0%, 并在培养30 d 内发挥显著作用。     

Heavy metal and volatile organic chemical removal and treatment in on-site wastewater systems

In Wisconsin, motor vehicle waste fluids (MVWF) enter catch basins along with rinse waters and are discharged to drainfields (soil absorption systems) after mixing with domestic wastewater in a septic tank (systems installed prior to 1992). The purpose of this study was to determine if removal/treatment of heavy metals and volatile organic chemicals (VOCs) found in spent oils, greases, and solvents occurs in drainfields that receive MVWFs. Soil samples were collected beneath and soil gas samples were collected above three gravel beds in drainfields installed in loamy sand or silt loam soils. Cadmium, chromium, and lead concentrations in soil 15 cm and greater beneath beds in loamy sand and silt loam soils were similar to background concentrations. Heavy metals in drainfields would most likely be found in the clogging layer at the infiltrative surface of gravel and soil. The VOCs 1,3,5-trimethylbenzene and m- and p-xylenes were found beneath beds in loamy sand soils; concentrations of detected VOCs ranged from 20–270 mg kg^?1. Volatile organic chemicals were not detected beneath the bed in silt loam soils. Drainfields in loamy sand soil appear to provide less treatment of VOCs compared to drainfields in silt loam soils. Volatile organic chemicals were found in soil gas above drainfields in both soil types. Thus, some VOCs diffuse from the drainfield to the soil surface.     

Calculating the density of loamy sandy soddy-podzolic soils from penetration resistance diagrams

The possibility for the calculation of the soil bulk density from two-dimensional penetration resistance diagrams drawn using a penetrometer during the vertical sounding of the soil has been discussed. A method has been proposed for calculating the bulk density of loamy sandy soddy-podzolic soils from the soil penetration test diagrams. The model for the calculation of the soil bulk density is based on the general physical concepts with the involvement of similarity theory methods. The adequacy and quality of the model have been studied statistically. The model has been found to be suitable for calculating the bulk density of loamy sandy and sandy podzolic soils.     

Suppression of root-knot nematodes in natural and agricultural soils

The potential of the invertebrate communities in agricultural and natural soils to suppress Meloidogyne incognita on coleus (Coleus blumei) was evaluated in two greenhouse experiments. Soil from adjacent natural and agricultural habitats was collected from four locations that had very different soil types (loamy sand, muck, sand and rock). Soil of each type was placed into pots, planted with coleus seedlings, inoculated with 2000 eggs of M. incognita, and arranged in a 4 × 2 factorial design. Root-knot nematodes were suppressed in natural soil compared to agricultural soil for loamy sand, sand and rock soils, but not for muck soil. Plants grew larger and had less root galling in natural soils than in agricultural soils. Free-living nematodes (bacterivores, fungivores, omnivores and predators) were monitored but did not show population patterns consistent with the suppression of root-knot nematodes observed in natural soils. Reasons for the opposite result (higher root-knot levels in natural than in agricultural soil) on muck soil are unknown, but this soil type was very different from the other soils in its unusually high organic matter content and very low levels of omnivorous and predatory nematodes. The agricultural muck in particular was unusually low in fungivorous nematodes and extremely high in levels of sodium and macronutrients. Despite the exception on the muck soil, the relative suppression of root-knot nematodes in natural compared to agricultural soils of the other three soil types (loamy sand, sand and rock) support the idea that potential for nematode suppression may be greater in natural than in agricultural soils.     

DMPP硝化抑制效果受其浓度、施用方式及土壤基质势的影响

The efficacy of nitrification inhibitors depends on soil properties and environmental conditions. The nitrification inhibitor 3.4-dimethylpyrazole phosphate （DMPP） was investigated in a sandy loam and a loamy soil to study its effectiveness as influenced by inhibitor concentration, application form, and soil matric potential. DMPP was applied with concentrations up to 34.6 mg DMPP kg^-1 soil as solution or as ammonium-sulfate/ammonium-nitrate granules formulated with DMPP. DMPP inhibited the oxidation of ammonium in both soils, but this effect was more pronounced in the sandy loam than in the loamy soil. When applied as solution, increasing DMPP concentrations up to 7 mg DMPP kg^-1 soil had no influence on the inhibition. The effectiveness of DMPP formulated as fertilizer granules was superior to the liquid application of DMPP and NH4^＋, particularly in the loamy soil. Without DMPP, a decline in soil matric potential down to -600 kPa decreased nitrification in both soils, but this effect was more pronounced in the sandy loam than in the loamy soil. DMPP was most effective in the sandy loam particularly under conditions of higher soil moisture, i.e., under conditions favorable for nitrate leaching.     

Contact angles at the water–air interface of hydrocarbon-contaminated soils and clay minerals

Contact angles at the water–air interface have been measured for triturated preparations of clays and soils in order to assess changes in their hydrophobic properties under the effect of oil hydrocarbons. Tasks have been to determine the dynamics of contact angle under soil wetting conditions and to reveal the effect of chemical removal of organic matter from soils on the hydrophilicity of preparations. The potentialities of static and dynamic drop tests for assessing the hydrophilic–hydrophobic properties of soils have been estimated. Clays (kaolinite, gumbrine, and argillite) have been investigated, as well as plow horizons of soils from the Republic of Tatarstan: heavy loamy leached chernozem, medium loamy dark gray forest soil, and light loamy soddy-calcareous soil. The soils have been contaminated with raw oil and kerosene at rates of 0.1–3 wt %. In the uncontaminated and contaminated chernozem, capillary water capacity has been maintained for 250 days. The contact angles have been found to depend on the degree of dispersion of powdered preparation, the main type of clay minerals in the soil, the presence and amount of oxidation-resistant soil organic matter, and the soil–water contact time. Characteristic parameters of mathematical models for drop behavior on triturated preparations have been calculated. Contamination with hydrocarbons has resulted in a reliable increase in the contact angles of soil preparations. The hydrophobization of soil surface in chernozem is more active than in soils poorer in organic matter. The complete restoration of the hydrophilic properties of soils after hydrocarbon contamination is due to the oxidation of easily oxidizable organic matter at the low content of humus, or to wetting during several months in the absence of the mazut fraction.     

Properties of soils in Southern Sikhote-Alin using the example of the Ussuri Reserve

The physical and physicochemical parameters of soils in the Ussuri Reserve presenting the typical soils of the Southern Sikhote-Alin were determined for the first time with consideration for the composition and structure of the soil cover. The soils in the surface horizons had loamy and clay loamy texture. It could vary depending on the overlain soil processes. All the soils were characterized by the minimum base saturation and an increase in the actual acidity down the profile. The organic matter was characterized by an abrupt decrease down the profile and the high mobility of the humus substances. The fractional-group humus composition was analyzed, and the humus status of the soils was characterized. The burozems were regarded as background soils, while a humus-illuvial podburs were referred to the rare ones. Recommendations were developed for the organization of soil monitoring with key test plots in different ecological conditions as examples.     

塔里木河中下游湿地及其周边土壤理化性状的空间异质性

研究塔里木河中下游湿地及其周边土壤理化性状,包括土壤粒度组成、土壤水分、盐分、pH和养分的空间异质性结果表明:大范围分布的土壤质地以沙质或粉沙质壤土为主,少数属壤质沙土或粉沙土,不同类型土地或植被条件下土壤粒度组成存在差异;土壤水分的空间分布特征反映了塔里木河中下游湿地的旱化现象;广泛分布的盐土、盐渍化土和碱化土表现出对植物生长发育的明显胁迫作用;土壤有机质、全N和全P总体贫乏,全K含量较高,反映了干旱区湿地土壤的特点。     

Fate of 15N-Labeled Potassium Nitrate in Different Citrus-Cultivated Soils: Influence of Spring and Summer Application

The fate of ¹⁵N-labeled potassium nitrate (8.5% ¹⁵N excess) was determined in 3-year-old Valencia orange trees grown in 1-m³ containers filled with different textured soils (sandy and loamy). The trees were fertilized either in spring (24 March) or summer (24 July). Spring fertilized trees gave higher fruit yields in sandy than in loamy soils, which exceeded summer fertilized trees in both cases. Summer fertilized trees had greater leaf biomass than spring fertilized trees. Fibrous root weight was 1.9-fold higher in sandy than in loamy soil. At the end of the cycle, tree N recovery from spring application was 45.7% for sandy and 37.7% for loamy soil; from summer fertilization, N recovery was 58.9% and 51.5% for sandy and loamy soils, respectively. The ¹⁵N recovered in the inorganic soil fraction (0?C90?cm) was higher for loamy (1.3%) than for sandy soil (0.4%). Fertilizer N immobilized in the organic matter was lower in sandy (2.5%) than in loamy soil (6.0%). Potential nitrate leaching from fertilizer (¹⁵NO ₃ ^? ?CN in the 90?C110-cm soil layer plus ¹⁵NO ₃ ^? ?CN in drainage water) was 34.8% higher in sandy than in loamy soil. The low N levels in sandy soil resulted from both higher NO ₃ ^? ?CN leaching losses and higher N uptake of plants grown in the former. The great root mass and higher soil temperatures could account for raised plant N uptake in sandy soil and in summer, respectively.     

Innovative soil management for sustainable pomegranate cultivation on skeletal soils

An innovative planting technique for pomegranate (Punica granatum L.) cv. Bhagwa in gravelly, shallow soils was standardized. Trapezoidal pits were dug in skeletal soils and filled with various types of soils, namely, gravelly, loamy, clayey, clayey mixed with sand and weathered rock. The clayey soil had the highest capacity to supply macronutrients (available N: 376.1, P: 47.1 and K: 761.6 kg/ha), and the loamy soil had the highest capacity to supply micronutrients (available Fe: 19.2, Cu: 8.1 and Zn: 1.83 ppm). The highest Mn (41.2 ppm), Zn (22.4 ppm), Cu (80.1 ppm) and chlorophyll (61.8) contents were observed in the leaves of plants grown in loamy soil. The highest number of hermaphrodite flowers was observed in loamy soil. Higher fruit quality in terms of higher juice content (49.3%), total soluble solids (TSS ) in fruit juice (15.7°B) and TSS :acid ratio (37.8) was produced in light‐textured soil. The highest fruit yield (4.28 t/ha) and cost‐benefit ratio (3.85) were obtained in clayey soil up to 0.60 m depth. This produced a 90.2% increase in yield, while total income was 147.4% higher than that obtained with weathered rock. However, when the pits were filled with clayey soils up to 1.20 m depth, disease prevalence increased, and yield was markedly reduced, to 2.25 t/ha. Thus, it may be concluded that skeletal soils could be used for pomegranate cultivation by refilling rhizosphere soil strata with clayey or loamy soil material up to 0.60 m depth.     

Compilation of schematic maps of soil pore space with the use of geoinformation and micromorphometric technologies

An analogy between the methodological principles and algorithms used in geographic information systems (GIS) and micromorphometric technologies makes it possible to integrate both technologies into a single information system. Certain parallels can be traced between the computer-based soil mapping and the computer-based analysis of soil microfabrics. The application of corresponding software in an integral system allowed the authors to develop a schematic map of the pore space structure in loamy soils distinguished on a fragment of the State Soil Map of Russia on a scale of 1: 1 M. The cartographic analysis of the resulting map shows the specificity of the pedogenic differentiation of the soil pore space in the loamy soils.