Sulfur Deficiency Research Articles

Contrasting gene expression patterns in grain of high and low asparagine wheat genotypes in response to sulphur supply

BackgroundFree asparagine is the precursor for acrylamide formation during cooking and processing of grains, tubers, beans and other crop products. In wheat grain, free asparagine, free glutamine and total free amino acids accumulate to high levels in response to sulphur deficiency. In this study, RNA-seq data were acquired for the embryo and endosperm of two genotypes of bread wheat, Spark and SR3, growing under conditions of sulphur sufficiency and deficiency, and sampled at 14 and 21 days post anthesis (dpa). The aim was to provide new knowledge and understanding of the genetic control of asparagine accumulation and breakdown in wheat grain.ResultsThere were clear differences in gene expression patterns between the genotypes. Sulphur responses were greater at 21 dpa than 14 dpa, and more evident in SR3 than Spark. TaASN2 was the most highly expressed asparagine synthetase gene in the grain, with expression in the embryo much higher than in the endosperm, and higher in Spark than SR3 during early development. There was a trend for genes encoding enzymes of nitrogen assimilation to be more highly expressed in Spark than SR3 when sulphur was supplied. TaASN2 expression in the embryo of SR3 increased in response to sulphur deficiency at 21 dpa, although this was not observed in Spark. This increase in TaASN2 expression was accompanied by an increase in glutamine synthetase gene expression and a decrease in asparaginase gene expression. Asparagine synthetase and asparaginase gene expression in the endosperm responded in the opposite way. Genes encoding regulatory protein kinases, SnRK1 and GCN2, both implicated in regulating asparagine synthetase gene expression, also responded to sulphur deficiency. Genes encoding bZIP transcription factors, including Opaque2/bZIP9, SPA/bZIP25 and BLZ1/OHP1/bZIP63, all of which contain SnRK1 target sites, were also expressed. Homeologues of many genes showed differential expression patterns and responses, including TaASN2.ConclusionsData on the genetic control of free asparagine accumulation in wheat grain and its response to sulphur supply showed grain asparagine levels to be determined in the embryo, and identified genes encoding signalling and metabolic proteins involved in asparagine metabolism that respond to sulphur availability.

A Cathode-Integrated Sulfur-Deficient Co9S8 Catalytic Interlayer for the Reutilization of “Lost” Polysulfides in Lithium–Sulfur Batteries

Lithium-sulfur batteries, with their high theoretical energy density and the low material cost of sulfur, are highly promising as a post-lithium ion battery contender. Their current performance is however compromised by sulfur loss and polysulfide shuttle to result in low energy efficiency and poor cycle stability. Herein, a catalytic material (Co9S8- x/CNT, nanoparticles with a metallic Co9S8 core and a sulfur-deficient shell on a CNT support) was applied as an interlayer on the sulfur cathode to retain migratory polysulfides and promote their reutilization. The Co9S8- x/CNT catalyst is highly effective for the conversion of polysulfides to insoluble end products (S or Li2S/Li2S2), and its deployment as a cathode-integrated interlayer was able to retain the polysulfides in the cathode for reuse. The accumulation of polysulfides in the electrolyte and the polysulfide shuttle were significantly reduced as a result. Consequently, a host-free sulfur cathode with the Co9S8- x/CNT interlayer had a low capacity fade rate of 0.049% per cycle for 1000 cycles at a 0.3C rate, a significant improvement of the capacity fade rate without it (0.28% per cycle for 200 cycles). The results here provide not only direct evidence for the contributions of sulfur deficiencies on the catalytic activity of Co9S8 in polysulfide conversion reactions but also the methodology on how the catalyst should be deployed in a Li-S battery for the best catalytic outcome.

Secondary and Micro Nutrient mapping in forest soils of Kandhamal district, Odisha

Emergence of widespread secondary and micro nutrient deficiencies have become major constraints of productivity. Farmers give hardly any emphasis on application of these nutrients. As a result decline or stagnation in production and productivity of many crops is observed creating a huge gap between the requirement and supply of food grains. For efficient soil and crop management soil test based fertilizer application is highly essential. major nutrient analysis is often done micro nutrient analysis is usually neglected due to prohibitive costs and expensive instruments. Data on soil micro and secondary nutrients status were used for by generation of soil fertility maps in GIS environment. In the present paper GPS based soil survey was conducted during 2012-13 where 595 nos. of spatially distributed georeferenced surface samples (0-20 cm depth) were collected from forest soils of Kandhamal district of Odisha and analysed for various secondary and micronutrients along with some basic parameters like pH, EC and OC. Derived thematic maps showed deficiency of Sulphur to an extent of 82.5% followed by Boron and Zn as the yield limiting elements of Kandhamal soils.

Lipid accumulation and biodiesel quality of Chlorella pyrenoidosa under oxidative stress induced by nutrient regimes

In this study, effects of media compositions on the suitability of Chlorella pyrenoidosa lipids for biodiesel production were investigated. The results indicate that sulfur deficiency and excessive phosphorus resulted in significant inhibition of cell growth. Moreover, the cellular lipid content increased under nitrogen-, phosphorus- or sulfur-deficient conditions, with the maximal lipid content of 48.90% and energy conversion efficiency of 8.89% being reached under nitrogen deficient conditions. In all runs, C16 to C18 components accounted for more than 95% of the total fatty acids. In addition, several biodiesel quality parameters were calculated according to the fatty acid profile, and principal component analysis and cluster dendrogram analysis were used to evaluate the quality of the corresponding biodiesel. A high similarity of biodiesel quality under nitrogen-, phosphorus- or sulfur-deficient cultivation was observed, and the biodiesel quality was better than those obtained under other culture conditions. Additionally, a strong correlation between lipid accumulation and reactive oxygen species level was confirmed. Overall, the work indicates that the lipid content of C. pyrenoidosa increased under nitrogen-, phosphorus- or sulfur-deficient conditions and the biodiesel quality was also improved.

A new approach for improving microalgal biohydrogen photoproduction based on safe & fast oxygen consumption

Microalgal H2 photoproduction has the potential of being an affordable method for producing this alternative fuel; however extreme sensitivity of hydrogenase enzyme to photosynthetic O2 naturally prevents large-scale H2 production upon illumination. Although a two-phase sulfur deficiency method has been established to deal with this incompatibility, its time and cost demanding, so that this model is not commercially scalable. Despite much research has been conducted, no proper economic alternative for the sulfur deprivation model, with higher or even same productivity and sustainability, has been presented till now. Herein we propose a simple and viable alternative, through introducing a chemical O2 scavenger system, called oxysorb, to algal cultures.Oxysorb, in non-cytotoxic concentrations (including 50 or 100 mM sodium ascorbate and 5 ppm cupric sulfate) for CC124 as well as pgr5 cultures (containing 30 μg/ml chlorophyll) showed a fast, safe and persisted O2 removal capacity, initiating H2 production in the sulfur-containing cultures, either in photoheterotrophic or in autotrophic conditions. Total H2 production obtained with CC124 and pgr5 cultures, containing 100 mM oxysorb, was 2–5.5 times higher than sulfur-deprived ones (measured in a small closed system). This higher H2 productivity in the oxysorb approach was achieved due to anoxia establishment with no ROS production and without impacting PSII activity.

Evaluation of sulfur source and dose on the nutritional state and production of piatã forage

Sulfur deficiency in soils has become a worldwide concern for agricultural production. This study aimed to evaluate the concequence of variable sulfur source and dosing on the nutritional status and production of Piatã forage in a dystrophic Ultisol. The experiment was arranged in a completely randomized block design with four replications. The 4 x 5 factorial treatments consisted of four sulfur sources (elemental sulfur pastilles [ESPA], gypsum [GY], gypsite [GI], and elemental sulfur powder [ESPO]) and five sulfur doses (0, 50, 100, 150. and 200 mg kg-1). The sulfur applications resulted in similar maximum shoot dry mass (SDM) production (16.66 to 17.69 g pot-1) with all sources. However, Piatã grass achieved maximum production in the treatments with 112 mg kg-1 of GI, 118 mg kg-1 of GY and ESPA, and 146 mg kg-1 of ESPO. The number of tillers, the leaf:stem ratio, and SPAD increased with increasing sulfur dose. The greatest increments of root dry mass (RDM) and of the tiller number were obtained with the ESPO source. Macronutrient concentrations in shoot dry mass tissue were in the order K > N > Ca > P > S > Mg. Low sulfur supply resulted in decreased Piatã grass growth with all sulfur sources tested. Differential responses were found with applications of different sulfur sources for SDM, RDM, and tillers number. The sources did not alter the leaf:stem ratio or SPAD index.

Sulfur-deficient MoS2-x promoted lithium polysulfides conversion in lithium-sulfur battery: A first-principles study

The lithium‑sulfur batteries are becoming the promising next generation large-scale electrical energy storage, due to the high specific energy density and theoretical capacity. During the charge/discharge cycle, the shuttle effect reduces the Coulombic efficiency and cycle performance, greatly limiting the practical application of lithium‑sulfur batteries. Two-dimensional materials metal sulfides are increasingly used in lithium‑sulfur battery cathode materials due to their low lithiation voltage, good conductivity, strong adsorption and catalytic effects of lithium polysulfide. Recently, sulfur-deficient MoS2-x was creatively introduced into the cathode material, leading to better electrochemical performance than the perfect MoS2. The modification factor of “sulfur deficiencies” for metal sulfides is an innovative approach to further suppress the shuttle effect and improve the lithium‑sulfur batteries performance. Understanding the specific working principle of sulfur-deficient MoS2-x would help to expand the application of defect metal sulfides. From experiment, the sulfur deficiencies are involved in the polysulfide conversion and enhance the conversion kinetics. However, the intuitive picture of how to enhance the conversion kinetics and the specific origins for the promotion effect are still unclear. A systematic theoretical study has been carried out on the molybdenum disulfide involved discharge process from S8 to Li2S. According to the calculation results, both the discharge process on MoS2 (001) and MoS2-x (001) surface undergo three consecutive “lithiation-cleavage” mechanism, with the last cleavage step Li4S2@MoS2 → Li2S@MoS2 as the rate-determining step. For MoS2-x (001), the product Li2S@MoS2-x is thermodynamically more stable, and the energy demands for the three cleavage steps are less than that of MoS2 (001) surface, which provide more thermodynamics and kinetic driving force for polysulfides conversion. Originally, the sulfur deficiency results in larger charge densities on MoS2-x (001) surface, enhance the interaction with the product and monomer molecules after cleavage, finally promotes the corresponding thermodynamic and kinetic processes.

Effects of deep placement of controlled-release nitrogen fertilizer on soybean growth and yield under sulfur deficiency

ABSTRACT Sulfur (S) and Nitrogen (N) metabolisms in plants are interacted and it is known that S deficiency decrease N absorption and metabolism. In leguminous plants S deficiency also decreases N2 fixation by rhizobia in the nodules. Deep placement of a controlled-release N fertilizer is a good method to provide nitrogen to soybean without inhibiting N2 fixation; thus, it was hypothesized that this method is able to provide nitrogen effectively to sulfur-deficient soybean plants. In this study effects of deep placement of coated urea on S-N physicological interaction, growth and productivity in soybean plants were examined using pot experiments. Soybean plants were grown with sulfate concentrations of 30, 100, or 1000 μM, with or without deep placement of coated urea. Shoot weights at the developing stage were not affected by S deficiency. SPAD values of leaves during the flowering stage decreased with S deficiency and increased with the deep placement of coated urea. S deficiency decreased seed weight per plant at the harvesting stage, but this decrease was attenuated by the deep placement of coated urea. N and S content in shoots at the developing stage increased with the deep placement of coated urea, whereas in seeds, only the N content increased. N2 fixation activity based on the relative ureide-N content in xylem sap indicated that the deep placement of coated urea did not inhibit N2 fixation activity at the early flowering stage. Without deep placement of coated urea, the relative ureide-N content decreased under S deficiency at the seed filling stage. These results suggest that the deep placement of coated urea is an efficient method to supply N to support soybean yield under S deficiency. Abbreviations: Deep+: with deep placement of coated urea; Deep–: without deep placement of coated urea

Contribution of Root Hair Development to Sulfate Uptake in Arabidopsis.

Root hairs often contribute to nutrient uptake from environments, but the contribution varies among nutrients. In Arabidopsis, two high-affinity sulfate transporters, SULTR1;1 and SULTR1;2, are responsible for sulfate uptake by roots. Their increased expression under sulfur deficiency (−S) stimulates sulfate uptake. Inspired by the higher and lower expression, respectively, of SULTR1;1 in mutants with more (werwolf [wer]) and fewer (caprice [cpc]) root hairs, we examined the contribution of root hairs to sulfate uptake. Sulfate uptake rates were similar among plant lines under both sulfur sufficiency (+S) and −S. Under −S, the expression of SULTR1;1 and SULTR1;2 was negatively correlated with the number of root hairs. These results suggest that both −S-induced SULTR expression and sulfate uptake rates were independent of the number of root hairs. In addition, we observed (1) a negative correlation between primary root lengths and number of root hairs and (2) a greater number of root hairs under −S than under +S. These observations suggested that under both +S and −S, sulfate uptake was influenced by the root biomass rather than the number of root hairs.

CLE-CLAVATA1 Signaling Pathway Modulates Lateral Root Development under Sulfur Deficiency.

Plant root system architecture changes drastically in response to availability of macronutrients in the soil environment. Despite the importance of root sulfur (S) uptake in plant growth and reproduction, molecular mechanisms underlying root development in response to S availability have not been fully characterized. We report here on the signaling module composed of the CLAVATA3 (CLV3)/EMBRYO SURROUNDING REGION (CLE) peptide and CLAVATA1 (CLV1) leucine-rich repeat receptor kinase, which regulate lateral root (LR) development in Arabidopsis thaliana upon changes in S availability. The wild-type seedlings exposed to prolonged S deficiency showed a phenotype with low LR density, which was restored upon sulfate supply. In contrast, the clv1 mutant showed a higher daily increase rate of LR density relative to the wild-type under prolonged S deficiency, which was diminished to the wild-type level upon sulfate supply, suggesting that CLV1 directs a signal to inhibit LR development under S-deficient conditions. CLE2 and CLE3 transcript levels decreased under S deficiency and through CLV1-mediated feedback regulations, suggesting the levels of CLE peptide signals are adjusted during the course of LR development. This study demonstrates a fine-tuned mechanism for LR development coordinately regulated by CLE-CLV1 signaling and in response to changes in S availability.

Glucosinolate Distribution in the Aerial Parts of sel1-10, a Disruption Mutant of the Sulfate Transporter SULTR1;2, in Mature Arabidopsis thaliana Plants.

Plants take up sulfur (S), an essential element for all organisms, as sulfate, which is mainly attributed to the function of SULTR1;2 in Arabidopsis. A disruption mutant of SULTR1;2, sel1-10, has been characterized with phenotypes similar to plants grown under sulfur deficiency (−S). Although the effects of −S on S metabolism were well investigated in seedlings, no studies have been performed on mature Arabidopsis plants. To study further the effects of −S on S metabolism, we analyzed the accumulation and distribution of S-containing compounds in different parts of mature sel1-10 and of the wild-type (WT) plants grown under long-day conditions. While the levels of sulfate, cysteine, and glutathione were almost similar between sel1-10 and WT, levels of glucosinolates (GSLs) differed between them depending on the parts of the plant. GSLs levels in the leaves and stems were generally lower in sel1-10 than those in WT. However, sel1-10 seeds maintained similar levels of aliphatic GSLs to those in WT plants. GSL accumulation in reproductive tissues is likely to be prioritized even when sulfate supply is limited in sel1-10 for its role in S storage and plant defense.

Activating transcription factor 4‐dependent B cell translocation gene‐1 induction promotes ferroptosis

Ferroptosis is a special type of programmed cell death that is characterized by iron‐dependent lipid peroxidation. The present study investigated the role of B cell translocation gene‐1 (BTG‐1) on sulfur amino acid deficiency (SAAD)‐mediated cell death. SAAD in HepG2 cells depleted the reduced glutathione, accelerated lipid peroxidation, increased cyclooxygenase 2 expression, and promoted cell death. SAAD‐mediated cell death was specifically inhibited by pretreatment with ferrostain or defroxamine, chemical inhibitors of ferroptosis. In parallel with cell death, SAAD increased expression of microtubule‐associated protein light chain 3‐II and facilitated acridine orange positive autophagic flux. Inhibition of autophagy accelerated the SAAD‐mediated cell death. Moreover, SAAD induced BTG‐1 expression in HepG2 cells. By using BTG‐1 promoter haboring reporter gene and siRNA, activating transcription factor 4 (ATF4) was identified as an essential transcription factor for SAAD‐mediated BTG‐1 induction. Knock out of BTG‐1 gene by CRISPR/Cas9 system decreased the cytotoxicity by SAAD. Furthermore, BTG‐1 deficiency increased microtubule‐associated protein light chain 3‐II and autophagic flux. Thus, present study demonstrates that SAAD induces ferroptosis, and the ATF4‐dependent BTG‐1 induction contributes to accelerate ferroptosis by inhibiting autophagy.Support or Funding InformationThis study was supported by the National Research Foundation of Korea (NRF) funded by Korea government (MSIP)(Grant No. 2018R1A5A2025272 and 2018R1A2B6007514).This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Engineering Vacancies in Bi2S3yielding Sub‐Bandgap Photoresponse and Highly Sensitive Short‐Wave Infrared Photodetectors

AbstractDefects play an important role in tailoring the optoelectronic properties of materials. Supported by density functional theory (DFT) calculations, herein it is demonstrated that sulphur vacancies are able to engineer sub‐band gap photoresponse in the short‐wave infrared range due to formation of in‐gap states in Bi2S3single crystals. Sulfurization and subsequent refill of the vacancies result in faster response but limit the spectral range to the near infrared as determined by the bandgap of Bi2S3. A facile chemical treatment is then explored to accelerate the speed of sulphur deficient (SD)‐based detectors on the order of 10 ms without sacrificing its spectral coverage of the infrared, while holding a high specific detectivity (D*) close to 1015Jones in the visible–near infrared range and 1012Jones at 1.6 µm. This work also provides new insights into the role sulphur vacancies play in the electronic structure and, as a result, in sub‐bandgap photoresponse enabling ultrasensitive, fast, and broadband photodetectors.

Water stress combined with sulfur deficiency in pea affects yield components but mitigates the effect of deficiency on seed globulin composition.

Water stress and sulfur (S) deficiency are two constraints increasingly faced by crops due to climate change and low-input agricultural practices. To investigate their interaction in the grain legume pea (Pisum sativum), sulfate was depleted at the mid-vegetative stage and a moderate 9-d water stress period was imposed during the early reproductive phase. The combination of the stresses impeded reproductive processes in a synergistic manner, reducing seed weight and seed number, and inducing seed abortion, which highlighted the paramount importance of sulfur for maintaining seed yield components under water stress. On the other hand, the moderate water stress mitigated the negative effect of sulfur deficiency on the accumulation of S-rich globulins (11S) in seeds, probably due to a lower seed sink strength for nitrogen, enabling a readjustment of the ratio of S-poor (7S) to 11S globulins. Transcriptome analysis of developing seeds at the end of the combined stress period indicated that similar biological processes were regulated in response to sulfur deficiency and to the combined stress, but that the extent of the transcriptional regulation was greater under sulfur deficiency. Seeds from plants subjected to the combined stresses showed a specific up-regulation of a set of transcription factor and SUMO ligase genes, indicating the establishment of unique regulatory processes when sulfur deficiency is combined with water stress.

Temperature controlled 1T/2H phase ratio modulation in mono- and a few layered MoS2 films

Along with hexagonal crystalline symmetry MoS2 (2H-MoS2), tetragonal structured MoS2 (1T-MoS2) possessing a peculiar optical and electrical properties shows attracting application in high-performance devices. On the other hand, instead of complicated and time-consuming techniques for the synthesis of 1T/2H mixed phase of MoS2, an efficient way to deposit mixed phase mono and a few layered MoS2 thin films for a very short span of time of 20 s has been realized by pulsed laser deposition. The 1T/2H phase ratio in monolayer to a few layered MoS2 films has been modulated by altering the substrate temperatures. Irrespective of deposition temperatures all the films showed a mixed phase structure while the 2H to 1T phase ratio increased from 66 to 84% with an increase in deposition temperature from 400 to 720 °C. The presence of 1T-2H mixed phase MoS2 layers was confirmed and their structural and optical properties were analyzed in nano (TEM), micro (Raman, AFM) and macro (ellipsometer) scale. The ellipsometer analysis demonstrated the A/B and C/D excitonic absorption peaks corresponding to 2H phase while the presence of 1T phase caused excess semimetal like charge density of the order of ~1020 cm−3. At low deposition temperatures, lack of sufficient energy to redistribute the impingement plasma particle to the most stable 2H-MoS2 phase led to a mixed phase of MoS2 film while sulfur deficiency induced defects and excess negative charges attributed to form 1T phase at the high deposition temperatures.

Sulfur fertilizer based on inverse vulcanization process with soybean oil

Sulfur deficiency in soils has become an increasing concern over the past decades. Despite elemental sulfur (S8) vast utilization as a commercial fertilizer, S8 has to be biologically oxidized for plant assimilation, drastically limiting its efficiency. Therefore, we propose a new fertilizer in which S8 structure is more accessible to oxidizing microorganisms by chemical modification via inverse vulcanization technique, a solvent-free copolymerization method, with soybean oil as comonomer. Sulfur oxidation experiments were performed by A. niger submerged cultivation, confirming that the homogeneous rubbery-like material provides enhanced oxidation, with great potential as multifunctional sulfur-fertilizer.

The Development of Li Batteries

For effective use of renewable energy it must be coupled to energy storage devices with high efficiencies. One such technology is a battery, where the stored chemical energy can be converted into the electrical energy through the electrochemical reactions. We started the Li battery studies since 2002. Currently, our research covers the Li-ion batteries, Li-S batteries, Li-O2 batteries, and all-solid-state batteries. Here, I will present some results relating to the electrode materials, electrolyte, and electrode achitectures in our group. We reported the Li-ion battery based on LiFePO4 cathode, which exhibits a good cyclability of 5,000 cycles and a considerable capacity retation of 90 % at -40℃. This novel type battery has been industied and applied for electric vehicles in the low temperature region. The NMC ternary battery and high-voltage battery based on LiNi0.5Mn1.5O2 are also introduced. Besides the cathode, some promising results relating to the anode part will be also introduced, including the graphene and VPO4/rGO. For Li-S battery, we firstly present a novel cathode of Mo2C nanorods-S composite, which exhibits a much lower capacity decay of 0.058 % per cycle at 2 C over 500 cycles. Additionally, the carbon-based separator decorated by red phsphorus nanoparticles for Li-S battery will be also introduced, which displays a good rate performance and a considerable cyclability of 500 cycles with 730 mAh/g. For Li-O2 battery, we reported the yolk-shell Co2CrO4 nanospheres as highly active catalysts. Based on the experimental results and DFT calculations, a direct evidence of Co2CrO4 employment being linked to the Li2O2 morphology was firstly provided and a catalytic mechanism was proposed. In addition, a 3D foam-like composite composing of Mo2C nanorods decorated by different amount of N-doped carbon was directly employed as the O2 electrode without applications of any binder and current collector. The fundamental information about the key factors and steps involved in the Li2O2 formation and decomposition was revealed. We will also introduce a flexible, self-standing, and binder-free O2 electrode by growing the flower-like MoS2 microspheres with sulfur deficiencies onto the CTs (Def-MoS2@CTs). Futhermore, I will introduce a novel electrolyte of a binary mixtures of highly concentrated tetraglyme electrolyte (HCG4) and 1,1,2,2-tetrafluoroethyl 2,2,3,3-tetrafluoropropyl ether (TTE) for the Li-O2 battery, which exhibits good wettability, enhanced ionic conductivity, considerable non-flammability, and high electrochemical stability. For all-solid-state battery, we will introduce a solid polyer electrolyte based on poly(ethylene oxide), which shows a superior electrochemical property with a decent lithium transference number of 0.35, a wide electrochemical stability window above 5 V vs. Li+/Li, and a low interfacial resistance. In addition, a triblock copolymer polystyrene-poly (ethylene glycol)-polystyrene (PS-PEG-PS) as the polymer electrolyte for all-solid-state battery will be also introduced, which displays a highly electrochemical stability and a considerable cyclability. Besides some fundermental results, I would like to introduce some industry-level developments in our pilot-line of batteries, because we cooperated with some enterprises of electric vehicles in China since 2009. I would like to apply an oral presentation if possible. Thanks for your consideration. Figure 1

Critical Sulfur Dilution Curve and Sulfur Nutrition Index in Maize

Core Ideas Critical S dilution curve was established for maize: S concentration = 2.13 × biomass−0.23. The S nutrition index successfully diagnosed S status at early crop stages (∼V6). Sulfur concentration and chlorophyll meter reading, both in the upper leaf, were good predictors of the S nutrition index. Sulfur (S) deficiency can severely limit maize (Zea mays L.) yield. This deficiency could be predicted by quantifying the S concentration (SC) in the shoot biomass (BM) and by calculating the S nutrition index (SNI = observed SC/critical SC). However, as shoot SC determination is laborious, alternative S diagnostic methods should be developed in maize. Thus, the objectives of our study were to: (i) determine and validate a critical S dilution curve, (ii) quantify the critical SNI, and (iii) explore the use of SC and chlorophyll meter reading (CMR), both determined in the uppermost developed leaf at vegetative growth stages, to predict SNI and for diagnosing S status in maize. Six field studies evaluating fertilizer S rates were executed, collecting maize shoot and uppermost developed leaf samples and determining Sc, CMR, yield, and SNI parameters. The main outcomes from our study were: (i) a maize critical S dilution curve was fitted (SC = 2.13BM−0.23) and validated with an independent dataset; (ii) a critical SNI threshold of 0.79 adequately diagnosed S status at ∼V6 stage; (iii) at V6, SNI was linearly related to SC (R2 = 0.65) and CMR (R2 = 0.85). As a result, a threshold value of 2.0 g S kg−1 for SC, 47.5 units for CMR, and 0.94 units for relative CMR can be used to successfully diagnose S deficiencies at early vegetative (∼V6) maize stages. Future studies testing S diagnostic tools for maize should be performed in environments with severe S deficiency and nutrient co‐limitations.

Plonowanie jęczmienia jarego w warunkach nawożenia siarką

In the last 20 years, due to a significant reduction in industrial emissions and changes in the assortment of available fertilizers, a progressive sulphur deficiency has been observed in the soils of Poland and other parts of the world. This creates the need to supplement NPK fertilizers with sulphur and to conduct research on the optimization of its use as a fertilizer component. A three-year field study was carried out on Haplic Luvisols with low content of sulphur available to plants. The aim of the study was to assess the effect of sulphur-containing fertilizers (ammonium sulphate, potassium sulphate and Wigor S) applied at rates of 20 and 40 kg S/ha on the yield of grain, straw and protein of spring barley. The study showed that application of sulphur, irrespective of its form, generally significantly increased the yield of spring barley grain and straw as compared to the control. However, no significant differences were found in the effects of the fertilizers on yield depending on either the fertilizer type or application rate. Protein content in the grain of the plants fertilized with sulphate sulphur was on average about 6% higher than in the grain of non-fertilized plants. As a result of the beneficial effect of sulphur on the yield of spring barley grain and on its protein content, the protein yield increased. The highest increases were obtained following application of sulphate fertilizers, especially at a 40 kg S/ha. The research suggests that irrespective of the form used, sulphur fertilization in the conditions of deficiency of this nutrient in the soil, with relatively high temperatures and high soil moisture, significantly affects the yield of spring barley grain and straw and the accumulation of protein in the grain.

Bi26Mo10O69–based solid solution with nonmetal dopants: Synthesis and properties

A series of S- and P- doped Bi26Mo10O69 was synthesized by conventional solid state method and studied. Chemical analysis detected closeness of experimental and theoretical ratios of bismuth, molybdenum and dopant for P-doped samples and 50% deficiency of sulfur for S-doped samples. The solid solutions ranges were determined to be x = 0–0.7 for Bi26Mo10−2xP2xO69−d and x = 0–0.6 for Bi26Mo10−2xSxO69−d. Stabilization of the monoclinic form is observed when x > 0.1 for P and x > 0.4 for S doping. The IR FT spectroscopy and Rietveld whole profile structure refinement at X-Ray diffraction data showed substitution of Mo by S and P forming SO4 and PO4 groups. The geometrical sizes of particles were determined to be in the range of 1–20 μm. Materials under study are characterized with total ionic conductivity of the 1 × 10−4 − 9 × 10−3 S cm−1 at 273–1073 K.