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Limited availability of phosphorus (P) in agricultural soils is a major cause of poor growth and yield of crops throughout the world. Optimization of crops productivity can be achieved by increasing the bioavailability of P via phosphate solubilizing bacteria (PSB), however, their effectiveness may vary with changing agro-climatic conditions That’s why current experiment was conducted to evaluate the potential of phosphate solubilizing bacteria (with PSB and without PSB) in improving growth and yield of wheat under different P levels (0, 25, 50, and 100 % of recommended P). The PSB with 100% recommended P significantly enhanced wheat tillers m−2, grains spike-1, grains and biological yield compared to the rest of the treatment’s combination. A significant improvement in 100 grains weight and rate of photosynthesis also validated the efficacious functioning of PSB and full recommended P. Furthermore, PSB were effective in optimizing wheat yield attributes at respective P level compared to Without PSB. Our findings imply that, PSB application along with 100% recommended P as inorganic phosphorus has potential to enhance wheat growth and yield over sole application of P fertilizers or PSB.

In this paper, a novel compound was developed by mixing H3PO4-modified cauliflower leaves hydrochar (CLH) and coal gangue-based Na-X zeolite (ZL). An alkaline soil contaminated with cadmium (Cd) and lead (Pb) was amended through the individual and synergistic application of CLH and ZL (1%CLH, 2%CLH, 1%ZL, 2%ZL and 1%CLH+1%ZL), and Chinese cabbage was grown on it. Individual application of CLH was superior to ZL on decreasing the pH of alkaline soil and increasing soil available phosphorus (Olsen-P) and soil organic matter (SOM). In contrast, their combined application significantly improved the soil cation exchange capacity (CEC). Besides, the 1%CLH+1%ZL was the most efficient treatment in decreasing DTPA-extractable Cd/Pb and concentrations of these two metals in cabbage root and shoot. Their synergistic application could better increase Cd and Pb immobilization and cabbage yield than their alone application. Furthermore, the immobilization of Pb for all treatments was higher than that of Cd. The synergistic immobilization mechanism of CLH and ZL reflected that the CLH precipitated and complexed with these two metals, which may block the pores of hydrochar or wrap on the surface of hydrochar. So the continuous adsorption and complexation were prevented. Nevertheless, ZL could probably alleviate this obstacle. This finding provides helpful information about using CLH combined with ZL as a soil stabilizer to immobilize heavy metals in contaminated alkaline soil.

Maintaining a proper content of selenium (Se) in food is particularly important for human health. However, the mechanisms of uptake and enrichment of Se ENMs in crops are still unclear. Herein, Se engineered nanomaterials (Se ENMs) (size 62.3 ± 14.6 nm and surface charge −34.4 ± 1.4 mV) were synthesized and used as nanofertilizers for Se-fortified vegetables. The results demonstrated the Se content and yield were increased by 338.0% and 19.8% respectively in Brassica chinensis L. through soil application of Se ENMs (0.5 mg‧kg–1). The content of Se in vegetables increased up to 32.8 μg/100 g (7.5 μg/100 g for the control), which could provide the daily recommended Se intake (55–400 μg/day) for human. Amendments of the slightly alkaline soil with the Se ENMs improved beneficial rhizosphere microbiomes (Pseudomonas and Bacillus), and resulted in the plants accumulating more low molecular weight compounds (betaine, proline, glycine, norleucine, urocanic acid and indole-3-acrylic acid) with increases in the Se content of the plant by 264.9%. Moreover, the nutrient accumulation in leaves promoted the photosynthesis (16.7%) and increased carbohydrate content (6.5%). Also, the expression of carbohydrate transport-related genes (BnSUC1,1, BnSUC1,4, and BnSWEET10,2) were up-regulated by 52.2, 53.2 and 76.3-fold, respectively, promoting root growth, improving rhizosphere microbiome and nutrient availability. Therefore, such mutual benefits between leaves and roots using ENMs could provide an alternative model for cultivating Se-enriched crops.

BACKGROUND Foliar application of highly concentrated ZnSO4 fertilizer improves Zn biofortification in wheat grains. However, excess ZnSO4 ·7H2 O concentration (≥ 5 g kg-1 , w v-1 ) has been associated with leaf burn and yield loss, necessitating the need for Zn sources with high threshold concentration. Therefore, the aim of this study, based on a 2-year field experiment conducted on wheat cultivated in acidic and alkaline soil, was to identify a suitable Zn formulation with a high Zn concentration or efficient adjuvant to achieve optimal Zn biofortification levels without compromising agronomic performance. RESULTS There was a continued increase in the Zn concentration of wheat grains and a decrease in grain yield with an increase in the concentration of the Zn foliar sprays in both soil types examined. Wheats treated with chelated Zn foliar sprays (ZnGly and ZnEDTA) had less foliar injury compared with those treated with unchelated Zn fertilizers. Furthermore, respective of wheat cultivars and soil types, ZnEDTA applied to wheat at a concentration of 10 g kg-1 achieved the highest grain Zn concentration without negatively affecting the wheat performance. Adjuvant type and concentration caused no significant variation in grain Zn concentration. CONCLUSION Overall, without foliar burn, wheat treated with 10 g kg-1 ZnEDTA foliar spray had the best performance with regards to grain Zn concentration and grain yield, which could have considerable implications for Zn biofortification of wheat grain. This article is protected by copyright. All rights reserved.

The present study aims to assess the effect of four inorganic soil amendments, such as lime (CaCO3), red mud consisting of 75% hematite (Fe2O3), gypsum (CaSO4·2H2O), and Al oxide (Al2O3), of an alkaline heavy metal-contaminated soil. For this purpose, a pot experiment was conducted by physically mixing individual six subsamples of a soil sample collected from Thessaly area with four inorganic soil amendments along with two leafy plants, spinach and lettuce. Al oxide causes the maximum reduction of the water-soluble Cu concentration, as its concentrations is no longer detectable. The Cu availability index decreases when aluminum oxide was used. The use of gypsum and red mud caused almost equal reduction while the smallest decrease was caused by the use of lime. The Zn availability index decreased equally when aluminum oxide and gypsum were mixed with the soil sample. The highest reduction of Cu and Zn transfer coefficient (TC) was observed when the Al2O3 was used. In spinach, Zn TC reduction was 39.8% and Cu TC reduction was 41.0%. In lettuce, the addition of Al2O3 led to Cu TC reduction of over 37.3% and Zn TC reduction of up to 38.7%. Generally, Al2O3 nanoparticles may function as suitable sorbents for the removal of Zn and Cu from soil samples, with an increasing effectiveness in spinach rather than lettuce. Liming materials seem to increase the soil alkalinity and promote the complexation of soluble heavy metals with hydroxide ions leading to immobilization of heavy metals in soil and reduce their amount in leafy vegetables. Remediation of contaminated soils is considered necessary to reduce environmental risks and to achieve the means available to increase agricultural production of safe and quality food.

X80 steel was buried in alkaline soil for 0.5, 1, and 2 years under conditions of natural burial, alternating current interference, and cathodic protection. The morphology and influence mechanism of X80 steel corrosion under nine different test conditions were studied through field data collection, macroscopic morphology observation, weight loss analysis, electrochemical methods, and corrosion product analysis. The results show that the rate of corrosion of X80 steel decreased with increase in the burial time under different test conditions. The corrosion rate of X80 steel under 15 VCSE and 30 VCSE alternating current interference increased at least 4.66 and 4.73 times, respectively, compared with that under natural environment. At the same time, the corrosion morphology exhibited more numerous and deeper pits. Under the cathodic protection of Mg or Zn, the corrosion rate of X80 steel decreased noticeably, whether under natural environment or under alternating current interference. The cathodic protection efficiency of Mg and Zn was higher than 76.04% under different test conditions and periods. The corrosion products of X80 steel were mainly found to be α-FeOOH and γ-FeOOH, and the overall structure of the rust layer was relatively stable. Moreover, the resistance of the rust layer on the sample surface under cathodic protection was small, which indicates that cathodic protection can effectively alleviate alternating current corrosion.

The nitrogen-15 (15N) natural abundance composition (δ15N) in soils or plants is a useful tool to indicate the openness of ecosystem N cycling. This study aimed to evaluate the influence of the experimental warming on soil and plant δ15N. We applied a global meta-analysis method to synthesize 79 and 76 paired observations of soil and plant δ15N from 20 published studies, respectively. Results showed that the mean effect sizes of the soil and plant δ15N under experimental warming were −0.524 (95 % CI (confidence interval): −0.987 to −0.162) and 0.189 (95 % CI: −0.210 to 0.569), respectively. This indicated that soil δ15N had negative response to warming at the global scale, where warming had no significant effect on plant δ15N. Experimental warming significantly (p3 ∘C in temperature, whereas it significantly (p

Iron (Fe) is an essential mineral for plants, and its deficiency as well as toxicity severely affects plant growth and development. Although Fe is ubiquitous in mineral soils, its acquisition by plants is difficult to regulate particularly in acidic and alkaline soils. Under alkaline conditions, where lime is abundant, Fe and other mineral elements are sparingly soluble. In contrast, under low pH conditions, especially in paddy fields, Fe toxicity could occur. Fe uptake is complicated and could be integrated with copper (Cu), manganese (Mn), zinc (Zn), and cadmium (Cd) uptake. Plants have developed sophisticated mechanisms to regulate the Fe uptake from soil and its transport to root and above-ground parts. Here, we review recent developments in understanding metal transport and discuss strategies to effectively regulate metal transport in plants with a particular focus on rice.

Sub-surface oil-polluted soils are frequently subjected to temporal groundwater table fluctuations during which the biological and chemical properties of the soil are expected to change in response to hydrological variations. In this study, we investigated the influence of decreasing groundwater levels on soil enzymatic activities, microbial community and total hydrocarbon dynamics. The changes in enzymatic activities, hydrocarbon removal efficiencies and bacterial community structure in the petroleum polluted soil were monitored by routine collection and testing of soil samples every 20 days over a period of 80 days in a laboratory column setup. Polymerase chain reaction and high-throughput sequencing of soil microbial DNA were used to determine the compositions of microorganisms, alpha and beta diversity in the polluted soil while the soil enzymatic activities and total petroleum hydrocarbon were measured using spectrophotometry and gas chromatography–mass spectrometry, respectively. The results showed that experimental decreases in groundwater levels over 80 days led to increased soil alkalinity, modulated enzymatic activities and enhanced total petroleum hydrocarbon attenuation in sub-surface soil. The findings from this study will be very useful in designing and optimizing bioremediation strategies for petroleum polluted soils from cold temperate regions.

Goal. To establish features of the influence of differentiation (address rationing) of mineral nitrogen fertilizers application on agrochemical indicators of dark chestnut weakly alkaline soil (the content of mineral nitrogen and humus) and crop yield. Methods. Field — to study the effect of gypsum and nitrogen fertilizer on the properties of dark chestnut soil and crop yields, laboratory analysis — o determine the content of mineral nitrogen and humus, mathematical — to assess the reliability of research results. Results. The application of mineral nitrogen fertilizers has led to a tendency to increase the content of mineral nitrogen in dark chestnut weakly alkaline soil. Fertilization and cultivation of crops did not affect the variability of mineral nitrogen content, which in general in the experiment remained moderate, the coefficient of variation did not change. Although the average amount of nitrogen fertilizer applied to the plots in the variant of differentiated application is 92.1 kg/ha, was less than in the plots with the maximum level of fertilizer, the yield did not differ from that with the maximum level of application and was reliably higher than in the variant with the average level of application. Conclusions. It is established that under the influence of growing crops and applying nitrogen fertilizers, the supply of dark chestnut weakly alkaline soil with mineral nitrogen improves at medium and maximum levels of fertilizer. It is established that the lack of fertilizer or low doses of nitrogen fertilizers increase the variability of the soil in terms of mineral nitrogen content, and the high level of application (390 kg/ha) for 6 years under 3 crops equalizes this indicator. There was a decrease in the variability of dark chestnut weakly alkaline soil in terms of humus content in the arable layer. A stable significant increase in the yield of grain and fodder crops depending on the levels of nitrogen fertilizer application has been also established. Differentiation of nitrogen fertilizers allows saving nitrogen fertilizers in the amount equivalent to almost 15 kg/ha of active substance per year in grain-feed 6-field crop rotation in the absence of a significant reduction in yield on dark chestnut weakly alkaline non-irrigated soils.

Polythionic acids, whose general formula is H2S n O6, with n greater than 2, were discovered in the aqueous solution of SO2 and H2S, known as the Wackenroder liquid. Their reactions with each other and with other reagents are, mostly, difficult to characterize, since such compounds readily decompose and interconvert, especially in solution. Nevertheless, they play an important role in technical applications (e.g., gold leaching, magnesium milling, cooling in metal processing) and in reactions of inorganic chemistry of sulfur. A few years ago, Shell-Paques/Paqell patented the first industrial process for the biological conversion of H2S into a colloidal mixture of sulfur and polythionates. Such hydrophilic sulfur can be used as a fertilizer and soil improver in agriculture in all but alkaline soils. Recently, Eni S.p.A. has developed to bench plant scale a new process, the HydroClaus process for the conversion of H2S into an acidic hydrophilic slurry of sulfur and polythionate ions. Such a slurry can be used as a soil improver where the very alkaline soil pH hinders the cultivation. The aim of this work is to study the laboratory-scale production of polythionates in view of the novel HydroClaus process scale-up at the industrial level. After the literature related to polythionates and their characterization has been revised, the sulfur-based mixture has been synthesized and the polythionate ions concentration has been determined. Also, the effect of the reaction operating conditions has been investigated to assess how they can influence the nature and the distribution of products in solution.

The pigment content in Blue-green algae is a specific feature of each species. The pigment variation is specific features among microalgae. The paper aim to analyze cyanobacterial extracts of different Usar soil of Azamgarh and Varanasi, Uttar Pradesh. The main object here is the importance of the blue green algae especially because of the pigments present in this class of algae. Pigments from natural sources are gaining more importance mainly due to health and environmental issues. Algae contain a wide range of pigments. Three major classes of pigments are chlorophylls, carotenoids (carotenes and xanthophylls) and phycobilins (Phycocyanin and phycoerythrin). Our present study investigates the efficiency for phycobiliprotein pigment production from four different cyanobacteria Hapalosiphon sp., Phormidium sp., Anabaena sp. and Nostoc sp. The harvested and dried biomass was subjected to extract pigments using different solvents. Thin Layer Chromatography was performed from extracted pigments using Acetone as extraction solvents. And running solvent especially for phycocyanin pigment was optimized and concluded that Petroleum ether and Acetone in the ratio of 7:3. This paper presents the information about the natural pigments of cyanobacteria and how they can be extracted and identified using different procedures and spectrophotometry. It emphasizes that the principal algal pigments are Phycobilins, Chlorophylls and Carotenoids.

This research aims to improve the efficiency of phytoremediation of Cd in soil using sunflowers and optimizing the model of Cd uptake by plants. Five low molecular weight organic acids (LMWOAs), oxalic acid (OA), acetic acid (AA), tartaric acid (TA), malic acid (MA), and citric acid (CA) at 2, 4, and 6 mmol/kg, were applied to sunflowers at 20, 30, and 40 days after seed emergence. The pH, electric conductivity (EC), total nitrogen (TN), total phosphorus (TP), catalase activity, amylase activity, invertase activity, and Cd content in rhizosphere soil and Cd in plant tissues were analyzed. Plant biomass was greater at the application rates of 2 and 4 mmol/kg. For each acid treatment, the Cd content in roots and leaves increased, while that of the stem and bud decreased. The total Cd accumulation increased due to the increase in plant biomass, especially root tissues; LMWOAs applied at 20 or 30 days after seedling emergence achieved higher Cd accumulations by expanding the Cd absorption capacity of rhizosphere soil. Application time had a more significant influence on plant biomass, Cd content, and accumulation in plant tissues than the variation of LMWOAs. Soil invertase activity and pH are the main factors causing the change in Cd form. An improved Freundlich model, using soil EC and pH, had higher accuracy than a model using pH alone. LMWOAs can increase Cd accumulation in plants, and a lower application rate (2 mmol/kg) and earlier application date (20 days after seedling emergence) are beneficial for improving the phytoremediation efficiency of sunflower. The increase of root biomass expanded the contact area between plants and soil, which was one of the reasons for the increase of Cd accumulation. EC could be used as a supplementary index to improve the Freundlich model when using pH.

Biochar has been considered as a potential way to enhance acidophilous plant growth in alkaline soils. However, whether such enhancements are closely linked with biochar pyrolysis temperature and its improvements in rhizospheric soil fertility and microbial activities remains largely unknown. We performed a pot experiment to investigate changes in azalea (Rhododendron) morphology and physiology, as well as its rhizosphere soil chemical and biological properties in a slightly alkaline urban soil under the amendment of biochars that pyrolyzed at three temperatures (i.e., 350, 550 and 700 °C). Our results showed that the effects of biochars on plant growth and soil properties depended on pyrolysis temperature. In comparison with the non-amended control, 350 and 550 °C biochars showed significant promotions on the azalea growth in terms of photosynthetic characteristics, biomass, root morphology, and N and P uptake. Whereas, 700 °C biochar showed an inhibition effect on them. 350 °C biochar decreased soil pH and increased soil available P and K contents and the activities of α-glucosidase, N-β-glucosaminidase, phosphatase and sulfatase. In addition, 350 °C biochar significantly enhanced bacterial 16S rRNA and fungal 18S rRNA gene abundances in the rhizosphere soil of azalea and mycorrhizal infection. Correlation analysis indicated that soil pH, available nutrients and fungal abundance had positive associations with the enhanced plant growth parameters. Therefore, our findings suggest that biochar produced at low temperature could be a feasible strategy for enhancing acidophilous azalea growth and improving urban soil quality.

Denitrification is a respiratory process by which nitrate is reduced to dinitrogen. Incomplete denitrification results in the emission of the greenhouse gas nitrous oxide and this is potentiated in acidic soils, which display reduced denitrification rates and high N2O/N2 ratios compared to alkaline soils. In this work, impact of pH on the proteome of the soil denitrifying bacterium Paracoccus denitrificans PD1222 was analysed with nitrate as sole energy and nitrogen source under anaerobic conditions at pH ranging from 6.5 to 7.5. Quantitative proteomic analysis revealed that the highest difference in protein representation was observed when the proteome at pH 6.5 was compared to the reference proteome at pH 7.2. However, this difference in the extracellular pH was not enough to produce modification of intracellular pH, which was maintained at 6.5 ± 0.1. The biosynthetic pathways of several cofactors relevant for denitrification and nitrogen assimilation like cobalamin, riboflavin, molybdopterin and nicotinamide were negatively affected at pH 6.5. In addition, peptide representation of reductases involved in nitrate assimilation and denitrification were reduced at pH 6.5. Data highlight the strong negative impact of pH on NosZ synthesis and intracellular copper content, thus impairing active NosZ assembly and, in turn, leading to elevated nitrous oxide emissions.

Release of silicon (Si) from different Si sources and Si budgeting in varied types of soils are required for the exploration of sustainable rice production. Si products are shown to be effective in...

The objective of the study was the composition of ash and slag waste from the Zmiiv TPP (thermal power plant) and the peculiarities of migration of heavy metals (HM) from the place of storage of ash and slag waste into the ecosystem. To achieve this goal, the following tasks were solved: chemical analysis of ash and slag waste of the Zmiiv TPP; identification of the probability of HM migration into the soil environment in the places of ash and slag waste storage. Ash and slag of the Zmiiv TPP contain Cu, Cr, As, Cd, Ni, Pb in quantities several times higher than the threshold limit value (TLV). For ash and slag wastes, the total pollution rate was Zc = 43, which corresponds to a high level. That is, this artificial horizon is dangerous. HMs migrate to groundwater and soils near the ash stockpiles as a result of infiltration of precipitation waters, leaks from water-bearing communications, water filtration through the base of the ash stockpiles of the Zmiiv TPP. To determine soil contamination near the ash stockpiles, we analyzed soil at the distances of 0, 5, 10, 50 and 100 meters. The contents of the HM decreased further away from the stockpiles. At the distance of up to 100 meters from the dump, there were excesses of the threshold limit values for Ni, Cu, As, Cr in the soil. The concentration factor exceeded one for Cr, As, Cu, Cd, Ni. Only at the distance of 100 meters did the contents of Pb and Zn reached the background values. The calculation of the total rate of soil contamination allowed us to classify these soils as moderately dangerous and acceptable. However, the Zn indicator has several significant disadvantages, particularly it does not take into account the differences in the potential hazards of the elements, as well as, most importantly, the synergistic effects of polymetallic pollution. The coefficient of synergistic effect of heavy metals was 26.64 (in the soil of the ash stockpiles), then decreased, but even at the distance of 100 meters it equaled 11.23, i.e. at the distance of 0... 100 m from the ash stockpiles, the overall actions exceed the norm. The study revealed that Cu, Ni, Zn and Cr had low mobility in the soil near the ash stockpiles and therefore accumulated near the stockpiles, which may be explained by neutral and slightly alkaline soil pH values. The ratio of mineral phases and glass varied, but we should note the predominance of aluminosilicates, calcium silicates and glass in the ash and slag wastes. Heavy metal compounds are confined mainly to amorphized clay aggregates and soot-coal ash formation, to a lesser extent to slag glass and even less to grains of quartz sand. Since ash contains such fractions that can be easily carried by the wind, it should be assumed that ingress of HM into the ecosystem occurs by air, which also contributes to air pollution. The solution to the problem of ash and slag waste disposal can be found in their utilization in the production of construction materials, in road construction, but it is necessary to study the composition of ash and slag and the probability of migration of HM depending on the conditions of use.

The Egyptian soil contains low organic matter and high calcium carbonate with a pH of 7.5–8.2, which reduces the availability of phosphorus (P) improve the efficiency of applying P fertilisers in alkaline soils. Therefore, the aim of this study is to evaluate the effect of biochar (B) at 0 t ha−1 and 10 t ha−1 with different P fertiliser rates (i.e. 0% P, 50% P, 100% P and 150% P of the recommended dose) on wheat yield (Triticum aestivum L.) and soil fertility in clay texture soil during the 2015–2016 and 2016–2017 growing seasons. The results show a significant increase in all of the following: soil availability and plant uptake of NPK; flag leaf area (FLA); the number of fertile tillers (NFT); the number of grains in spike (NGS), and the grain yield of wheat plants treated with P fertiliser alone, or when P fertiliser combined with biochar addition. FLA increased by 81.82% and 72.27% in the plots treated with biochar during the 1st and 2nd seasons respectively. Wheat uptake of total nitrogen–P–potassium (NPK) increased as a result of increasing the concentration of inorganic P in the studied soil. It is noteworthy that adding biochar to P fertiliser supplements P-fertiliser such as in the treatment of 10 t ha−1 biochar at 50% P, where the highest grain yield was recorded compared with adding 100% P and 150% P of the recommended dose. The results indicated that integrating biochar and P fertiliser can be a practical approach to improve wheat production and soil fertility.

Growing attention has been paid to greenhouse gases (GHG) viz. carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O), due to their contribution to global warming. Biochar is used widely in agricultural soils to improve some soil properties, enhance soil nutrients, and mitigate GHG emissions. However, the previous studies on acidic soils reported contradictory results of CO2, CH4, or N2O emissions due to various factors that vary based on the properties of soil and biochar. The data on the impact of biochar application on GHG emissions in alkaline soils are limited, and because of the alkaline nature of biochar, it is expected to behave similarly as on acidic soil. However, contradictory results are noticed also in the alkaline soils, especially in CO2 and CH4. Therefore, this review gives insight into the contradictory results of CO2, CH4, or N2O emissions as affected by biochar with a special focus on alkaline soils and the potential factors included in this process.

The study presents soil alkalinity control using three different bio-materials for soil sustainability and productivity. It has been noted that soils without balanced pH have trouble with nutrient solubility, thereby making soil nutrients unavailable for plants. 5kg soil sample was measured and put in five different containers. Thereafter, 450g of ash was added to four containers to induce alkalinity. Moreover, three samples were further mixed with 3 different treatments; treatment A, B and C. In all, five samples were set for the study, sample A (control or ordinary soil), B (soil + ash), C (soil + ash + poultry droppings), D (soil + ash + cassava peals) and E (soil + ash + dry grasses). pH tests’ were conducted weekly on the samples and the results subjected to ANOVA test. Results obtained were 7.2, 11.5, 9.5, 8.7 and 9.2 for samples A, B, C, D and E respectively in week 1. Similarly, 7.2, 11.5, 8.4, 8.2 and 9.0; 7.2, 11.5, 7.8, 7.9 and 8.7; 7.2, 11.53, 7.4, 7.5 and 8.2 for samples A, B, C, D and E were obtained in 2nd, 3rd and 4th week respectively. The results showed that the treatments have significant effect in reducing alkalinity (p = 5%).

Phytoremediation using Miscanthus is a valuable technique for the restoration of saline‐alkaline soil, but the potential is not quantified. To assess this potential, a 5 years field experiment was conducted on saline‐alkaline soils with three genotypes of Miscanthus and an unplanted control. The bulk soil (0–20‐cm depth) physicochemical properties were measured annually from 2015 to 2018, while the bacterial and fungal community structures of the rhizosphere soil were investigated by high‐throughput sequencing after 5 years under Miscanthus (2018). The results showed that Miscanthus cultivation on saline‐alkaline soil reduced soil salinization and improved soil fertility on this site. Specifically, compared with the blank control, the five‐years Miscanthus cultivation (mean of three different genotypes pooled) decreased the soil pH by 0.33 units (8.78–8.45) and electrical conductivity by 23.4 μS/cm (226.7–203.3 μS/cm), as well as increasing soil organic matter content from 18.9 to 34.9 g/kg and total potassium content from 15.2 to 18.0 g/kg. In addition, the soil improvement was more pronounced with a longer duration of growth. Miscanthus remediates saline‐alkaline soils by altering the microbial community compositional abundance rather than its diversity. The improvement is due to enrichment of beneficial bacteria leading to soil desalinization (e.g., by Gemmatimonadaceae), litter decomposition (e.g., by Chitinophagaceae), plant growth promotion (e.g., by Micrococcaceae), and the reduction of harmful fungi (e.g., Pleosporales and Chitinophagaceae). Soil pH, electrical conductivity, organic matter, and total potassium were the main physicochemical properties affecting bacterial and fungal communities. Our results quantify the soil improvement potential of Miscanthus and clarify the underlying microbial mechanisms, laying a solid foundation for further implementation of saline‐alkaline soil phytoremediation using Miscanthus. In the future, more extensive multi‐location trials are required to assess if these improvements are seen across a wide diversity of environments.

Aim: Amelioration effect of soil amendment on growth and yield of Vigna unguiculata L. grown in acidic and alkaline soils. Study Design: The study was conducted in a randomized complete block design with five replicates. Place and Duration of Study: Department of Botany, University of Calabar, Nigeria, between May and September, 2017. Methodology: Composite soils from two locations Akamkpa (pH 4.0) and Odukpani (pH 9.0) were collected, mixed thoroughly with organic manure (OM) and agricultural lime (AL) singly and in combination, allowed to stay three weeks for proper blending before V. unguiculata seeds were sown. On seedlings germination, amelioration effect of soil amendment on growth and yield of cowpea grown in acidic and alkaline soils was studied at different periods of growth. Results: Results revealed significant (P=0.05) increase in leaf area, plant height, number of leaves, leaf fresh and leaf dry weight, relative growth rate, net assimilation rate and leaf area ratio of V. unguiculata grown in acidic and alkaline soils treated with OM and AL. Pod length, number of pods plant-1, number of seeds pod-1, number of seeds plant-1, weight of 100 seeds increased significantly. Organic manure used singly and in combination was more effective in ameliorating soil pH effect than AL. Vigna unguiculata performed better in treated and untreated alkaline than in acidic soils. Least plant height for V. unguiculata grown in untreated alkaline soil at 12 weeks after sowing WAS was 60.22±0.16a cm and highest 119.63E2±.35g cm for plants grown in soil treated with AL1+OM1. Least number of seeds plant-1 for plants grown in untreated acidic soil at 12 WAS was 90.60±0.02a and the highest 139.18E2±0.02e for plants grown in soil treated with AL1+OM1. Conclusion: An improvement in growth and seed yield of V. unguiculata grown in acidic and alkaline soils is feasible through the use of organic manure and agricultural lime.

Previously, studies of microbial fertilizer were mainly focused on isolation of the functional strains; the comparison among carriers of the fertilizer was seldom studied. In the current paper, we ...

This study aims to evaluate the TiO2 nanoparticles (NPs) and soil type effect on Zea mays L. seedlings and to assess the effect of the TiO2 NPs retained in organic matter on terrestrial isopods (Armadillidium vulgare, Latreille). It was hypothesized that (i) the combined effect of soil pH and minerals, and the addition of TiO2 NPs harm maize plants, and (ii) increasing Ti’s content in organic matter (OM) causes mortality in the isopods. Under greenhouse conditions, the effects of TiO2 NPs (300 and 600 mg kg−1 dry soil) were assessed during 21 days in acid or alkaline soils, with an organic matter layer above the soil surface (3 cm). An inhibitory effect of TiO2 NPs on plant length and root size was clearly shown at 21 days in alkaline soil but not in acid soils. Besides, a higher amount of Ti was accumulated on maize tissues in alkaline soil than those grown on acid soil. An increase in TiO2 NPs caused higher Ti concentrations in the soil organic matter (SOM), which harmed the survival and weight of the terrestrial isopods when the OM is consumed. Isopods limit the consumption of NPs at high concentrations while the NPs leached toward soil deeper layers allowing a reduction in plant height and root size in Z. mays plants grown in alkaline soil. Nevertheless, further investigations on the effect of TiO2 NPs in the association of plants and terrestrial isopods in natural conditions are required.

The association and diversity of Arbuscular Mycorrhizal Fungi (AMF) in trap cultures from soil derived inocula of limestone mine sites of Mawsmai village, Cherrapunjee, Meghalaya were studied for one crop cycle using Maize (Zea mays L.) as the trap plant under laboratory conditions. Rhizospheric soil samples from three mine sites and un-mined site were collected for the entire study based on the degree of disturbance; limestone mine spoils less than 2 years (LMS2), limestone mine spoils less than 8 years (LMS8), limestone mine spoils more than 14 years (LMS14) and adjacent un-mined forest site (CPF). A low to high level of AMF root colonization was observed in trap cultures of LMS2, LMS8, LMS14 and CPF derived inocula. A total diversity of 77 AMF species belonging to 17 genera were isolated and identified from trap cultures. The AMF species with 100% isolation frequency were Acaulospora lacunosa, A. laevis, Funneliformis coronatum, F. geosporum, F. mosseae, Gigaspora margarita, Gi. rosea, Glomus ambisporum, Gl. botryoides, Gl. citricola, Gl. fasciculatum, Gl. macrocarpum, Rhizophagus intraradices and Septoglomus constrictum. Highest species diversity and richness was observed in LMS14 followed by CPF while lowest in LMS2. Highest species dominance was found in LMS2 while lowest in CPF. The Bray Curtis resemblance matrix was highest between LMS14 and CPF while lowest in LMS2 and LMS14. The diversity of AMF from limestone mine spoils and un-mined forest site is highly remarkable in terms of species richness and composition and this will be the first report from North Eastern India to harbour a good number of AMF species diversity from alkaline soils. The objective of this study is to assess the diversity of AMF in trap cultures isolated from limestone mining sites and un-mined forest soil for taxonomic identification of AMF species, establishment of monospecific cultures and large scale production of AMF stress tolerance species. These resilient AMF species will be beneficial for re-vegetation of the mine spoils which can guaranteed and help plants to become established in the mining ecosystem.

Fertilizer phosphorus (P) is a finite resource, necessitating the development of innovative solutions for P fertilizer efficiency in agricultural systems. Myo-inositol hexakisphosphate (phytate) constitutes the majority of identified organic P in many soil types and is poorly available to plants. Incorporating phytase-producing biofertilizers into soil presents a viable and environmentally acceptable way of utilizing P from phytate, while reducing the need for mineral P application. A deeper understanding of the microbial ecology in relation to degradation of phytate under natural soil conditions is however needed to obtain successful biofertilizer candidates able to compete in complex soil environments. Here we present the development of a microcosm for studying microbial communities able to colonize and utilize Ca-phytate hotspots in solum. Our results provide evidence that the recruited microbial population mineralizes Ca-phytate. Furthermore, quantification of bacterial genes associated with organic P cycling in alkaline soils indicated that the phosphatases PhoX and PhoD may play a larger role in phytate mineralization in soil than previously recognized. Amplicon sequencing and BioLog® catabolism studies show that hotspots containing Ca-phytate, recruited a different set of microorganisms when compared to those containing an addition of C source alone, with the genus Streptomyces specifically enriched. We propose that Streptomyces represents an hitherto unexplored resource as P biofertilizer with competitive advantage for utilizing CaPhy in an inherently competitive soil environment. We further conclude that the use of our newly designed microcosm presents an innovative approach for isolating soil microorganisms with the potential to degrade precipitated phytate in solum.

Purpose High-silicon chromium iron (HSCI) has been used in ground grids in southern China, while there was a lack of study on its corrosion behavior in this soil environment. The purpose of this paper is to discover the corrosion of HSCI in acidic and alkaline soil solutions. Design/methodology/approach The original defects on the HSCI surface were observed using optical microscopy, and the corrosion behavior of the HSCI in the acidic and alkaline soil solutions were jointly detected using electrochemical measurements and scanning electron microscopy/energy dispersive spectrometer. Findings The results showed the corrosion rates of the HSCI in the acidic and alkaline soil solutions were limited, and the high contents of Cr and Si in matrix was responsible for its high corrosion resistance. The HSCI showed a similar corrosion tendency in the two solutions, while its corrosion rate in the acid soil solution was higher than that in the alkaline soil solution. The corrosion pits on the specimen surface were originated from the original defects in matrix, and the edges of the corrosion pits were more rounded than the original defects after 720 h immersion in the two solutions. The original defects in the HSCI matrix played a significant role in the corrosion process. Originality/value The paper discovered the corrosion evolution of HSCI in the acidic and alkaline soil solutions. What is more, the acceleration role of the original defects on the corrosion of the HSCI in the acidic and alkaline soil solutions was discovered in the paper. The results are beneficial for the material selection of ground grid equipment in engineering.

Muscadine (Muscadinia rotundifolia) grapes have been used in grape variety and rootstock development due to their inherent pest and disease resistance, but little is known about their alkaline soil tolerance. In this study, Muscadine varieties, commercialrootstock and interspecific hybrid grape (Vitis spp.) cultivars were evaluated for alkaline soil tolerance under field conditions to determine the potential suitability of muscadines for rootstock development. Thirty-one muscadine and eleven interspecific hybridgrape cultivars were grown in a moderately alkaline soil (pH = 8.1) over a three-year period. Alkaline soil tolerance wasdetermined by relative vine vigour (shoot length), vine nutrient status (whole leaf tissue testing) and visual chlorosis. Additional data were collected on the timing of budbreak. Overall, the muscadines studied expressed low vigour and had greater chlorosissymptoms than the interspecific hybrid rootstocks (Paulsen 1103, Millardet et de Grasset 101-14, Millardet et de Grasset 420A,Ruggeri 140, Schwarzmann, and Matador). These parameters were not correlated with the concentration in any specific nutrient, although nutrient deficiencies (nitrogen, copper) and excesses (calcium, boron) were observed in the muscadine varieties.Overall, the muscadine grapes expressed poor alkaline soil tolerance compared to interspecific hybrid grape rootstocks (1103P, 101-14 MGt., 140Ru, Schwarzmann, 420A, and Matador), even the ones having poor alkaline soil tolerance (101-14 MGt., Schwarzmann) and own-rooted cultivars (Black Spanish, Blanc Du Bois, Dunstan’s Dream and Victoria Red). Nevertheless, some variability in chlorosis symptoms and nutrition was observed across the muscadine group, suggesting some interests to select Muscadine hybrid rootstocks less sensitive to iron chlorosis.

A microcosm study was established using three arable soils differing in both physicochemical properties and AOB or AOA dominance of ammonia oxidization. Nitrification and N2O emissions were quantified under 10 Pa C2H2, 1-octyne, or 3,4-dimethylpyrazole phosphate (DMPP), and the community composition and abundance of AOA and AOB were assessed. Amendment of soil with DMPP had a comparable effect to 1-octyne on AOB activities, composition, and N2O emissions across soils. By blocking AOB activity, both DMPP and 1-octyne supported higher rates of AOA growth in both the acid and alkaline soils. Approximately, 50% of ammonia-oxidizing activity in the acid soil was attributed to AOB activity by phylotypes affiliated with Nitrosomonas communis. When AOB were blocked by DMPP or 1-octyne across all soils, recovery of AOA communities was associated with the increased abundance of Nitrososphaera viennesis.

Chinese seabuckthorn (Hippophae rhamnoides) is an important economic and ecological tree species widely distributed in regions of extreme cold and drought in China. In this study, we examined the ecological and physiological response of Chinese seabuckthorn to saline-alkali stress. The results showed that the relative growth in height and base-diameter, as well as biomass, photosynthesis rate, water potential and nonstructural carbohydrate content, are significantly affected by saline-alkali soil under SS1 (0.2% of the mixed salt solution NaHCO3: Na2CO3: NaCl: Na2SO4 = 9:1:81:9) and SS2 (0.5% of the mixed salt solution NaHCO3: Na2CO3: NaCl: Na2SO4 = 9:1:81:9) conditions. The soluble salt content in the soil was approximately 8.87–9.22 g·kg−1 and the pH was above 8.02. After applying 2.0 kg/m3 saline-alkali soil conditioner (invented by Shanxi Agricultural University and granted a national invention patent in China, ZL2010-1–0,281,671.1), the growth and physiological status of Chinese seabuckthorn seedlings recovered compared to the control, and the content of soluble salt decreased to 7.29–7.86 g·kg−1. These results indicated that saline-alkali stress inhibits the normal growth and development of Chinese seabuckthorn seedlings and the application of suitable soil conditioner improves the soil conditions and promotes growth development. The results of this study will provide a theoretical basis for vegetation restoration, comprehensive utilization of saline-alkaline land, and will contribute to ecological development in China.

Periphyton plays an indispensable role in coastal saline‐alkali land, but its function is poorly understood. Soil physical and chemical properties (pH value, salinity, soil organic matter), enzyme activity, and microbial diversity (based on 16 s rDNA, ITS and functional genes) were measured in periphyton formed on rice‐growing coastal saline‐alkali soil modified by a new type of soil conditioner. The results showed that the content of organic matter and catalase activity in periphyton were significantly higher than in the unplanted control soil. Soil pH and salinity were decreased in periphyton compared to the unplanted control soil. Based on the relative abundance, bacterial genera Desulfomicrobium, Rhodobacter, cyanobacterium_scsio_T−2, Gemmatimonas, and Salinarimonas as well as fungal genus Fusarium were more abundant in periphyton than the unplanted control soil. In terms of functional genes, the cbbM and cbbL sequencing showed higher abundance of Hydrogenophaga, Rhodovulum, Magnetospira, Leptothrix, and Thiohalorhabdus, whereas the nifH sequencing indicated higher abundance of Cyanobacteria in the periphyton compared to the unplanted soil. The relative abundance and community structure of soil microorganisms were improved by periphyton, thus reducing soil salinity and pH, and increasing soil organic matter and enzyme activity. This indicated that the periphyton can improve the conditions and offer a suitable environment for plant growth in coastal saline‐alkali soil.

Soil was sampled (0–20 cm) from a 5-year Yellow River Delta paddy field experiment: no fertilizers (Control), mineral fertilizers (NPK), and NPK plus organic fertilizer (soybean and bean litter) applied at rates of 450 and 900 kg C ha− 1 (NPKC1 and NPKC2). The aggregate size, labile carbon fractions and root growth were investigated in combination with microbial community structure by high-throughput sequencing. NPKC1 and NPKC2 fertilization decreased Na+ content, but increased available nitrogen, phosphorus and Ca2+ contents. Macroaggregate formation was increased under NPKC1 (by 28 %) and NPKC2 (by 62 %) fertilization through increase of labile carbon fractions (particularly microbial biomass carbon), as well as better root growth. NPKC1 and NPKC2 fertilization increased microbial diversity and enriched the microbial community towards taxa responsible for aggregate stability (e.g., Actinobacteria and Ascomycota). RDA revealed that dissolved organic carbon content was the main factor affecting microbial community composition. Combined mineral and organic fertilizers decreased Na+ content, increased macroaggregates due to broader microbial diversity, increased contents of labile organic carbon and Ca2+. Consequently, combined organic and mineral fertilization were the best practice to increase microbial biomass and labile carbon fractions that strongly contribute to aggregate formation in saline-alkaline soil. Soil structure is a key factor in sustainable agriculture, especially for saline-alkaline soils, because Na+ destroys clay minearls and colloids, and thus, prevents the aggregate formation. We assessed the effects of organic amendments in combination with mineral fertilizers on chemical properties, microbial community composition and aggregate formation in a typical saline-alkaline soil.

The choice of phosphate fertilizer has a special concern in alkaline soils due to its direct effect on the availability and uptake of phosphorus and micronutrients, as it can affect the rate of ammonia volatilization. This study aims to increase potato productivity in alkaline soils and reducing ammonia emissions by using acid fertilizers and controlling the amount of irrigation water. Two-year field trials were conducted in 2018 and 2019 growing seasons to investigate the influence of irrigation levels and P fertilizers on potato yield and ammonia volatilization from Arenosols. Potato (Solanum tuberosum, L.) cv Kara Spp. plants were irrigated at 75 or 100% of the evapotranspiration (ET75 and ET100) and were fertilized with monopotassium phosphate (MPP) or urea phosphate (UP), beside a control treatment without P addition. UP minimized the soil pH to 6.95 and 7.00 in the ET75 and ET100 treatments, respectively, compared to 7.80 and 7.85 in the case of MPP. The maximum potato tubers yield was achieved from ET100 and UP. The cumulative NH3 volatilization ranged between 33 and 85 N kg ha−1 per season which was accounted for 12 to 27% of the total applied nitrogen. UP and ET100 minimized the N loss from 27 to 12%. Reducing the levels of added water increased the quality of tubers and efficiency of the added water, but it caused a significant loss in the total and marketable yield and elevated the rate of ammonia emissions from the calcareous sandy soils. The acidic P fertilizers are effective in reducing the ammonia loss and increase the availability of micronutrients.

Miscanthus, a perennial rhizomatous C4 grass, has emerged as a promising lignocellulosic crop. To avoid competition with food crops, marginal lands especially saline–alkaline soil are being recommended to grow Miscanthus across China. However, the challenges such as high cost and low reproduction coefficient associated with the propagation methods are impeding its large‐scale plantation in saline–alkaline soil. In this study, a “two‐steps” propagation method was designed, which was comprised of two phases: (1) seedling cultivation and (2) seedling strengthening. The parameters (substrate composition and plug size) for this method were determined. The optimal substrate composition of the seedling bed for M. sinensis, M. lutarioriparius, and their interspecific hybrids was peat and perlite at a ratio of 3:2, 3:1, and 3:3 by volume, respectively. The seedlings were transplanted into the plugs to deliver robust plantlets. The most appropriate plug size for M. sinensis, M. lutarioriparius, and their interspecific hybrids was 50 plugs (50 cm3/plug), 72 plugs (40 cm3/plug), and 72 plugs (40 cm3/plug), respectively. Three propagation methods, that is, direct sowing of seeds, rhizomes plantation, and “two‐steps” seed‐derived plugs for M. lutarioriparius were compared in saline–alkaline soil over 3 years (2014, 2015, and 2016). The establishment rate of the seeds directly planted was poor (zero). The performance (e.g., biomass yield) of the plants derived from the “two‐steps” seed‐derived plugs was better than that of the plants derived from rhizomes directly planted. Therefore, the “two‐steps” seed‐derived plugs can be regarded as an effective propagation method to upscale Miscanthus cultivation in saline–alkaline soil.

In situ remediation techniques are currently limited for agricultural soil contaminated by heavy metal(loid)s, particularly for alkaline soil. In this study, we applied the amendments (Chinese loess, attapulgites, and composted sludge) to a contaminated alkaline agricultural soil to compare their effectiveness in immobilizing heavy metal(loid)s. Soil was collected from the uppermost 20 cm of a heavily contaminated cornfield in Baiyin, China. The amendments were added to the soil at the ratios of 1%, 5%, 10%, and 15%. Controls without amendment were also included. The effectiveness of amendments was evaluated using single extractions and Tessier sequential extraction procedure. The extractants in the single-step extraction were H2O, calcium chloride (CaCl2), diethylenetriaminepentaacetic acid (DTPA), and hydrochloric acid (HCl). Seed germination was performed with the soil after immobilization for 180 days. Chinese loess effectively reduced the toxicity of heavy metal(loid)s and improve seed germination rates compared with attapulgites (ATPs) and composted sludge. Composted sludge effectively transformed heavy metal(loid)s, particularly Cu, from the carbonate fraction into the organic matter or the residual fraction. The concentrations of heavy metal(loid)s extracted with DTPA were positively correlated with the summation of the exchangeable and carbonate fractions (P < 0.05). A high seed germination rate could be obtained when the four amendments were added at the ratios between 5 and 10%. Chinese loess was effective and safe to immobilize heavy metal(loid)s in contaminated alkaline agricultural soil. DTPA performed the best in predicting the availabilities of As, Cd, Pb, Cu, and Zn in the soil.

Land degraded by salinization and alkalization is widely distributed globally and involves a wide range of ecosystem types. However, the knowledge of the indigenous microbial assemblages and their roles in various saline-alkaline soils is limited. This study demonstrated microbial assemblages in various saline-alkaline soils from different regions of Inner Mongolia and revealed the key driving factors to influence microbiome. The correlation network analysis indicates the difference in adaptability of bacterial and fungal communities under stimulation by saline-alkaline stress: fungal community shows higher tolerance, stability, and resilience to various saline-alkaline soils than a bacterial community. The keystone bacteria and fungi that have potential adaptability to various saline-alkaline environments are further identified, and they may confer benefits in restoring saline-alkaline soils by their own effects or assisting plants. For salt-rich soils in different regions, the soluble salt ion components are the major determinant to drive microbial assemblages of different saline-alkaline soils, rather than salinity. Thus, these saline-alkaline soils are clustered into sulfated, chlorinated, and soda-type saline-alkaline soils. Multivariate analysis reveals unique, dominant, and common microbial taxa in three saline-alkaline soils. This result of the conceptual mode indicates that potential roles of unique and dominant microbial taxa on regulating saline-alkaline functions are more vital.

This study investigated the chemical and physical mechanisms associated with the movement of water and salt in saline-alkali soil amended with different types of biochar. Four types of biochar were selected: ordinary laboratory-prepared biochar (BC), acidified biochar (HBC), particle size modified biochar (NBC), and composite modified biochar (HNBC). The physical and chemical properties of the biochar treatments were characterized. Vertical infiltration simulation tests were conducted to analyze the effects of modification on the adsorption and distribution of salt ions on biochar, and the soil water-stable macro-aggregates in saline-alkali soil. The porous structure, specific surface area (SSA), micropore volume (VMIC), and H/C value were increased by acidification, particle size modification, and composite modification. Compared with BC, HBC and HNBC enhanced the O/C and (O+N)/C values, thereby increasing the hydrophilicity. The vertical infiltration tests showed that the depth of the soil wetting peak and cumulative infiltration were both higher than in the control (CK) after adding biochar, where HBC had the greatest water retention capacity. The modified biochar reduced the salt content and water-soluble Na+ content of the soil profile by increasing the soil water content and adsorbing Na+. The modified biochar promoted the formation and stabilization of soil water-stable macro-aggregates. Amending soil with HBC showed the greatest reduction in salt content and increased water-stable macro-aggregation. HBC improved the water retention and Na+ adsorption capacity of biochar. This enhanced the formation of soil water-stable macro-aggregates and improved the effects of biochar on saline-alkali soil by altering soil physical and chemical properties.

Applying proper soil amendments in arid and semi-arid areas improves soil quality and promotes plant growth. Lignite and Wheat Straw Biochar (WSB) are soil amendments that can be used to improve soil quality and plant productivity. Nitraria Schoberi L. is a halophyte shrub from Nitrariaceae family that is planted in degraded rangelands for forage production and soil conservation. In this research, we investigated the effects of lignite and WSB on structural traits (e.g., height, crown diameter, area and volume, leaf area, perimeter, etc.) of N. Schoberi and soil properties. The lignite and WSB amendments were applied at rates of 0, 1.25, 2.5, and 3.75% (weight/weight) in six replications. The experiment was conducted in pots inside a greenhouse. Statistical analysis was performed by one-way and two-way analyses of variance using the SPSS21 statistical software. Our results revealed that lignite and WSB amendments significantly improved soil properties and increased structural traits of the N. Schoberi. Trait enhancement was considerably increased by incorporating a larger ratio of amendments to soil during the experiment. In particular, we found that an application of 3.75% (w/w) of both amendments among the ones tested provided the best rate to reach the largest improvement in soil properties and the largest growth of N. Schoberi. The results demonstrated that lignite and WSB can be used to enhance soil chemical and biological properties to promote the productivity of N. Schoberi. Our results suggest that the application of lignite and WSB effectively improved poor soil properties in the studied clay loam solonchak rangeland soil. We recommend incorporating these amendments in the restoration of rangelands with alkaline soils using N. Schoberi.