Phytoremediation of nickel by quinoa: Morphological and physiological response

The amount of soil contaminated with heavy metal increases due to urbanization, industrialization, and anthropogenic activities. Quinoa is considered a useful candidate in the remediation of such soil. In this pot experiment, the phytoextraction capacity of quinoa lines (A1, A2, A7, and A9) against different nickel (Ni) concentrations (0, 50, and 100 mg kg-1) were investigated. Required Ni concentrations were developed in polythene bags filled with sandy loam soil using nickel nitrate salt prior to two months of sowing and kept sealed up to sowing. Results showed that translocation of Ni increased from roots to shoots with an increase in soil Ni concentration in all lines. A2 line accumulated high Ni in leaf compared to the root as depicted by translocation factor 3.09 and 3.21 when grown at soil having 50 and 100 Ni mg kg-1, respectively. While, in the case of root, A7 accumulated high Ni followed by A9, A1, and A2, respectively. There was a 5–7% increased seed yield by 50 mg kg-1 Ni in all except A1 compared to control. However, growth and yield declined with a further increase in Ni level. The maximum reduction in yield was noticed in A9, which was strongly linked with poor physiological performance, e.g., chlorophyll a, b, and phenolic contents. Ni concentrations in the seed of all lines were within the permissible value set (67 ppm) by FAO/WHO. The result of the present study suggests that quinoa is a better accumulator of Ni. This species can provide the scope of decontamination of heavy metal polluted soil. The screened line can be used for future quinoa breeding programs for bioremediation and phytoextraction purpose.

A Baseline Survey of The Geochemical Characteristics of the Arctic Soils of Alexandra Land Within the Franz Josef Land Archipelago (Russia)

The composition of soils and their parent materials were studied within one of the most northern land areas of the world – the island of Alexandra Land of the Franz Josef Land archipelago. Contents of 65 trace and major elements were determined using atomic emission spectrometry (ICP-AES) и inductively coupled plasma spectrometry (ICP-MS). Other analyzed characteristics included soil pH, particle-size distribution and contents of carbon and nitrogen. The mineralogical composition of rocks was determined in thin sections. The studied soils were formed on basalts with high contents of MgO, Fe2O3, TiO2, Сu, Co, V, Ni, Cr, Zn, and low contents of Pb and Hg. The composition of soils was generally similar to that of the bedrock. The median concentrations (mg kg-1) of trace elements in the soils were as follows: Cu - 160, Zn - 101, Ni - 74, Pb - 2.9, Cd - 0.14, and Hg - 0.031. The bedrock had an alkaline pH, whereas the soil pH ranged from weakly acid to alkaline. The textural class of the soils predominantly corresponded to sandy loam. The contents of clay and silt increased with depth due to the migration of these fractions with groundwater. The concentrations of ecologically hazardous Hg and Pb were slightly increased in the upper layer of soils and correlated with carbon contents, which was indicative of bioconcentration processes.

Free and Immobilized Microbial Culture–Mediated Crude Oil Degradation and Microbial Diversity Changes Through Taxonomic and Functional Markers in a Sandy Loam Soil

Crude oil contamination of soil and water resources is a widespread issue. The present study evaluated the degradation of aliphatic hydrocarbons (C11–C36) in crude oil by 17 bacteria isolated from a crude oil–contaminated soil. The results suggested that Pseudomonas sp. and Bacillus amyloliquefaciens were the best hydrocarbon-degrading bacteria in the presence of surfactant Tween-80 (0.1% w/v). Based on the present investigation and a previous study, Pseudomonas sp. + B. amyloliquefaciens and fungus Aspergillus sydowii were identified as best oil degraders and were immobilized in alginate–bentonite beads, guargum–nanobenonite water dispersible granules (WDGs), and carboxy methyl cellulose (CMC)–bentonite composite. Sandy loam soil was fortified with 1, 2, and 5% crude oil, and total petroleum hydrocarbon (TPH) degradation efficiency of free cultures and bio-formulations was evaluated in sandy loam soils. Compared to a half-life (t1/2) of 69.7 days in the control soil (1% oil), free cultures of Pseudomonas sp. + B. amyloliquefaciens and A. sydowii degraded TPH with t1/2 of 10.8 and 19.4 days, respectively. Increasing the oil content slowed down degradation, and the t1/2 in the control and soils inoculated with Pseudomonas sp. + B. amyloliquefaciens and A. sydowii was 72.9, 14.7, and 22.2 days (2%) and 87.0, 23.4, and 30.8 days (5%), respectively. Supplementing soil with ammonium sulfate (1%) enhanced TPH degradation by Pseudomonas sp. + B. amyloliquefaciens (t1/2–10 days) and A. sydowii (t1/2–12.7 days). All three bio-formulations were effective in degrading TPH (1%), and the t1/2 was 10.7–11.9 days (Pseudomonas sp. + B. amyloliquefaciens and 14–20.2 days (A. sydowii) and were at par with free cultures. Microbial diversity analysis based on taxonomic markers and functional markers suggested that the bioaugmentation process helped keep soil in the active stage and restored the original microbial population to some extent. The present study concluded that bio-formulations of crude oil–degrading microbes can be exploited for its degradation in the contaminated environment.

Experimental Study of Hysteresis in Clayey Soils under Compression

The energy dissipation for one cycle of clay soil deformation over the area of ​​a hysteresis loop under conditions of one-dimensional deformation has been experimentally studied. Several series of trials were carried out under different conditions of soil density and moisture and different loading modes. It was established by the experiments that after several cycles of loading and unloading of the samples, the transient process of the closed loop formation ends and certain dependences of stress on deformations are established in the sections of the ascending and descending branches of the hysteresis loop. To determine these dependencies, rheological relations obtained directly from the hysteresis loop by approximating the arcs of its contour have been used. By integrating the approximating rheological dependences along the branches of the loop, the dissipated energy per deformation cycle has been obtained as a function of cyclic deformation amplitude, measured by the area of the hysteresis loop. Experiments on obtaining a hysteresis loop were carried out on a compression device with a cyclic sample. Samples with different states of density and moisture content were produced by consolidating a paste having yield point moisture under different pressures. Several series of experiments have been carried out. In the first series, soil absorption coefficients were derived for different states of density-moisture at different loading rates. In the second series, three types of clayish soil (clay, loam, sandy loam) were studied. Dissipation coefficients have been found out for the indicated soils. In the third series, three types of clay soil were tested under different conditions of density and moisture. The dissipation coefficients have been obtained. In the fourth series, the dependences of the absorption coefficient on the amplitude value of the cyclic stress for three types of clay soil were disclosed. It was found that a change in the loading rate within the range from 0.05 MPa to 0.2 MPa does not lead to the significant change in the absorption coefficient, the increase in the number of clay fractions in the sample leads to an increase in the absorption coefficient, a change in the amplitude of cyclic loading (in the indicated range of change) does not affect the absorption coefficient.

Field Test of In Situ Groundwater Treatment Applying Oxygen Diffusion and Bioaugmentation Methods in an Area with Sustained Total Petroleum Hydrocarbon (TPH) Contaminant Flow

Contamination of groundwater by petroleum hydrocarbons is a widespread environmental problem in many regions. Contamination of unsaturated and saturated zones could also pose a significant risk to human health. The main purpose of the study was to assess the efficiency of biodegradation of total petroleum hydrocarbon (TPH) in situ, in an area with loam and sandy loam soils, and to identify features and characteristics related to groundwater treatment in an area with a persistent flow of pollutants. We used methods of biostimulation (oxygen as stimulatory supplement) and bioaugmentation to improve water quality. Oxygen was added to the groundwater by diffusion through silicone tubing. The efficiency of groundwater treatment was determined by detailed monitoring. Implementation of the applied measure resulted in an average reduction in TPH concentration of 73.1% compared with the initial average concentration (4.33 mg/L), and in the local area, TPH content was reduced by 95.5%. The authors hope that this paper will contribute to a better understanding of the topic of groundwater treatment by in situ biodegradation of TPH. Further studies on this topic are particularly needed to provide more data and details on the efficiency of groundwater treatment under adverse geological conditions.

Agrotechnological passport of the potato variety Azart

Цель исследований: изучить реакцию нового среднераннего сорта картофеля Азарт селекции ФГБНУ «ФИЦ картофеля имени А.Г. Лорха» на густоту, сроки посадки и способы внесения минеральных удобрений, по комплексу хозяйственно ценных признаков (морфологические и биологические особенности, потребительские и столовые качества клубней, урожайность, показатели качества клубней, устойчивость к болезням, лежкость при хранении). Опыты проводили на экспериментальной базе «Коренево» ФГБНУ «ФИЦ картофеля имени А.Г. Лорха» (Московская область) в 2018–2020 годах на дерново-подзолистой супесчаной почве с низким содержанием гумуса (1,8–1,9%), высоким – подвижного фосфора (269–278 мг/кг почвы) и ниже среднего – обменного калия (128–130 мг/кг почвы). Минеральные удобрения (азофоска с добавлением калимагнезии) вносили локально двумя лентами при нарезке гребней культиватором КРН-4,2 с туковысевающими аппаратами в середине апреля. Изучали три приема внесения: 1. Единовременное N90P90K135(контроль); 2. Дробно-локальное (стартовое N60P60K90+ подкормка N30P30K45) через 7–10 дней после всходов; 3. Дробное (стартовое N30P30K45 + подкормка N30P30K45) через 7–10 дней после всходов + подкормка N30P30K45 в фазе бутонизации. Посадку картофеля проводили в два срока: ранний (третья декада апреля при температуре почвы не ниже 5–7 °C) и базовый (контроль) – через 7–10 дней после первого срока. Клубни массой 50–80 г высаживали клоновой сажалкой СН-4Б-К на глубину 8–10 см. Исследовали три густоты посадки: 44 (контроль), 50 и 56 тыс. клубней/га по схеме 75×30, 75×27, 75×24 см. Определен наиболее эффективный агрокомплекс приемов, включающий раннюю посадку (третья декада апреля при температуре почвы не ниже 5–7 °C) с густотой 44 тыс. клубней/га на фоне дробно-локального внесения удобрений (стартовое N60P60K90при нарезке гребней + подкормка N30P30K45) при междурядной обработке через 7–10 дней после всходов. В условиях дерново-подзолистой супесчаной почвы Центрального региона Нечерноземной зоны сорт дает прибавку урожая в размере 3,9 т/га, или 10,3%. При этом условный доход составил 39,0 тыс. р/га. The purpose of the research: to study the reaction of a new medium-early potato variety Azart selection of the Russian Potato Research Centre on the density, planting dates and methods of applying mineral fertilizers, according to a complex of economically valuable characteristics (morphological and biological features, consumer and table qualities of tubers, yield, quality indicators of tubers, resistance to diseases, storage shelf life). The experiments were carried out at the experimental base Korenevo Russian Potato Research Centre (Moscow region) in 2018–2020 on sod-podzolic sandy loam soil with low humus content (1.8–1.9%), high – mobile phosphorus (269–278 mg/kg of soil) and below average – exchangeable potassium (128–130 mg/kg of soil). Mineral fertilizers (azofoska with the addition of kalimagnesia) were applied locally with two ribbons when cutting the ridges with a KRN-4,2 cultivator with tow-raising devices in mid-April. We studied three methods of making: 1. One-time N90P90K135 (control); 2. Fractional-local (starting N60P60K90 + top dressing N30P30K45) 7–10 days after germination; 3. Fractional (starting N30P30K45+ top dressing N30P30K45) 7–10 days after germination + top dressing N30P30K45 in the budding phase. Potato planting was carried out in two terms: early (the third decade of April at a soil temperature of at least 5–7 °C) and basic (control) – 7–10 days after the first term. Tubers weighing 50–80 g were planted with a clone planter CH-4B-K to a depth of 8–10 cm. Three planting densities were studied: 44 (control), 50 and 56 thousand tubers/ha according to the scheme 75×30, 75×27, 75×24 cm. The most effective agrocomplex of techniques has been determined, including early planting (the third decade of April at a soil temperature of at least 5–7 °C) with a density of 44 thousand tubers/ha against the background of fractional-local fertilization (starting N60P60K90when cutting ridges + top dressing N30P30K45) with row-to-row processing 7–10 days after germination. In the conditions of sod-podzolic sandy loam soil of the Central region of the Non-Chernozem zone, the variety gives an increase in yield of 3.9 t/ha or 10.3%. At the same time, the conditional income amounted to 39.0 thousand rubles/ha.

Influence of tillage methods on the yield of winter rye variety Sudarushka

The results of studying the elements of the technology of cultivation of a new variety of winter rye Sudarushka are presented. The research took place in 2019, 2020 in the sub-taiga zone of the Tomsk region. The impact of soil cultivation methods as well as the impact of humic fertiliser from peat Gumostim on the yield of winter rye Sudarushka is evaluated. The soils of the experimental plot are acidic (pH 4.3) soddy-podzolic loamy sandy loam. The arable horizon has a low humus content (1.5%), a low (0.2 mg/100g) content of nitrate nitrogen, a medium content of mobile phosphorus (19.2) and exchangeable potassium (7.1) and a high (11.0 mg/100g) content of mobile aluminium. The scheme of the experiment included four variants of cultivation: ploughing of fallow lands with PlN-4-35 + cultivation KPN-4,2, sowing without packing and with packing; disking with BDMK-2,8 + cultivation KPN-4,2, sowing without packing and with packing. Treatment with humic fertilizer from peat Gumostim at a concentration of 0.001% was carried out during the growing season in the beginning phase of the leaf-tube formation. The average yield of winter rye in the variety Sudarushka during the years of research was 4.66 t/ha in the variant with disking, subsequent cultivation before sowing and further sowing with packing, which is 0.34 t/ha higher than with the traditional method of soil cultivation. The application of humic fertilizer from peat Gumostim on cold sod-podzolic soils enabled the average yield of winter rye to be 4.31 t/ha y, which is 0.39 t/ha higher than without the fertilizer.

Soil Texture Distribution for East Wasit Province, Iraq

Soil texture affects many physical and chemical properties of soil. Knowledge of soil texture is essential for all water and soil studies. The aim of the research is to draw a map of the spatial distribution of soil texture in the region of eastern Wasit province and know the relationship of texture to the soil’s hydrological groups. Laboratory tests were conducted on 25 soil samples. With a depth of 50-75 cm, were selected from locations that represent the study area. According to the unified classification system, The results showed that the soil texture for the samples locations was 40% sand, 16% for both silt loam and sandy loam, 12% for loamy sand, 8% for both sandy clay loam and sandy loam. A soil texture classification map was produced for the study area. The first soil texture map for the area differs significantly from the World Food and Agriculture Organization soil texture classification map. It adopts signed tests of the site. The statistical analysis showed that the per cent sand’s standard deviation was 22.65%, silt 19.247%, and 6.416% clay. It turns out that 52% of the soil models from hydrologic group A, 24% from hydrologic group B and 24% from hydrologic group C, Arc GIS software was used to produce maps.

Carbon balance of sandy loam soils in arid landscapes of the Chechen Republic

The spatial variability of the stability of soil aggregates and its relationship with runoff and soil erosion were studied in a semi-arid environment in the field in order to assess the validity of the stability of structures as an indicator of soil erosion in soils of sandy loam ridges. The influence of soil and relief properties on the variability of aggregate stability was also investigated. Significant relationships were found in the number of water droplets required to break down the aggregate, as well as the rate of runoff and erosion. The most significant correlation was found between the number of droplet impacts and the soil organic matter content. The stability of aggregates in the upper soil layer is apparently a valuable indicator of field runoff and inter-season soil erosion of sandy loamy ridges in semi-arid conditions.