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Purpose The highly efficient degradation bacteria were selected from the humus from the very cold straw in China for many years to construct the in situ degradation bacteria, and the degradation efficiency of corn straw was determined by process optimization. Methods According to the main components of corn straw, through morphological, physiological, and biochemical screening, three highly efficient complementary degradation strains were selected to construct the compound flora, and the degradation efficiency was analyzed by Fourier transform infrared spectrometer, field emission scanning electron microscope, and X-ray diffractometer. Result The corn straw selected in this paper is mainly composed of cellulose (31.99%), hemicellulose (25.33%), and lignin (14.67%). Through the determination of enzyme activity, strain Streptomyces sp. G1T has high decomposition ability to cellulose and hemicellulose but weak utilization ability to lignin; strain Streptomyces sp. G2T has the strongest decomposition ability to cellulose and hemicellulose among the three strains. The decomposition ability of strain Streptomyces sp. G3T to lignin was the strongest among the three strains. Therefore, by compounding the three strains, the decomposition ability has been greatly improved. The optimal process conditions obtained by single factor and response surface method are as follows: pH is 7, temperature is 30 °C, inoculation amount is 5%, rotational speed is 210 rpm, and the weight loss rate of straw is 60.55% after decomposing for 7 days. A large amount of degradation of corn straw can be seen by Fourier transform infrared spectrometer, field emission scanning electron microscope, and X-ray diffractometer. Conclusion Streptomyces sp. G1T, Streptomyces sp. G2T, and Streptomyces sp. G3T screened from straw humus in very cold areas were used to construct in situ degradation bacteria, which had good straw degradation activity and had the potential to be used for straw treatment in cold areas after harvest. This characteristic makes the complex bacteria become a strong competitive candidate for industrial production, and it is also an effective biotechnology in line with the current recycling of resources.

Crop productivity in Albic soil is poor, owing to poor soil physicochemical properties. Mixing of Aw layers, representing Albic soil, with B layers, could improve the physicochemical properties of Albic soil, which is characterized by poor humus on the topsoil and high penetration resistance. The objective of the present study conducted in 2015-2016 in an Albic soil region in Heilongjiang province, China, was to explore the effects of different soil mixing strategies on the physicochemical properties of Albic soil and crop yield. There were four soil mixing treatments: conventional subsoiler (CS), three-stage subsoil mixing plough (TSMP), four-stage subsoil mixing plough (FSMP), and three-stage subsoil interval mixing plough (TSIMP). Our results demonstrated that the Aw layer bulk density of Albic soil under TSMP, FSMP, and TSIMP decreased significantly compared to that under CS. In addition, the total porosity of the soil under these treatments increased significantly in 2 years. Compared to the water holding capacity under the CS treatment, other treatments increased significantly in the Aw layer. Furthermore, soil penetration resistance of the Aw layer decreased following Aw and B layer mixing. All three soil mixing treatments also increased soil aggregate stability and cation exchange capacity but reduced soil organic carbon content in the Aw layer. Soil mixing increased soybean and maize seed yield. Overall, Aw and B layer mixing improved Albic soil structure and physiochemical properties and increased crop yield; thus, this mixing is a feasible approach for Albic soil improvement, with optimal improvements observed under the FMSP strategy, which also added organic substances to the Aw layer.

Designing highly efficient catalysts for use in fuel production is a highly attractive research area but still remains challenging. Herein, for the first time, ultrafine Ni nanoparticles (NPs) self-assembled on ceria nanowires (NWs) and then embedded in a microporous silica shell (denoted as Ni-CeO

Due to the widespread use of heavy machinery, improper soil tillage practices, and insufficient soil organic materials input, soil compaction has become a major issue affecting soil function in modern agriculture and the sustainability of the environment. The aim of the present study was to evaluate the responses of soil mechanical parameters to soil water content and soil organic matter content (SOM), and to investigate the physical properties of nine disturbed soils in a black soil region in Northeast China. The soil samples were capillary saturated and subjected to 6, 10, 100, 600, and 800 kPa soil water suction (SWS), and pre-compression stress (σp), compression index (Cc), and decompression index (Dc) were measured. SWS and SOM, and their interaction, significantly influenced the mechanical parameters. σp increased with an increase in SWS until 600 kPa, while Dc exhibited an opposite trend with an increase in SWS. Cc had a peak value at SWS of 100 kPa. All mechanical parameter values were higher under high SOM than under low SOM. σp, Cc, and Dc were influenced variably by different soil physicochemical factors. Structural equation modeling results revealed that soil mechanical parameters were directly and indirectly influenced by soil texture and mean weight diameter of aggregates, in addition to SOM and SWS. According to the results of the present study, based on soil mechanical and physical properties, increasing SOM and ensuring suitable soil water content during tillage could be applied as management strategies to minimize further soil compaction and improve soil resilience, and thus promote the sustainable development of agriculture in Northeast China.

Chemical park is regarded as a major contributor of VOCs emissions in China. Currently, a green and safe technology, microbial fuel cells (MFCs), is being developed for the VOCs abatement. Noting that effective electron transfer is critical to the MFC performance. In this work, flavin mononucleotide (FMN) was dosed as an electron shuttle to improve the removal of the typical toxic VOCs, toluene. The experimental results revealed that the performance of toluene removal and power generation were accelerated with the dosage of 0.2–2 μM FMN. With the addition of 1 μM FMN, the removal efficiency, the maximum output voltage and the coulombic efficiency of MFC were increased by 18.4%, 64.4% and 56.3%, respectively. However, a further increase in FMN concentration to 2 μM caused a reduction in the removal efficiency and coulombic efficiency. The images of scanning electron microscopy and confocal laser scanning microscopy showed that the presence of FMN greatly promoted the microbial growth and its activity. Furthermore, microbial community analysis also implied that the moderate dosage of FMN (0.2–1 μM) was beneficial for the growth of the typical exoelectrogens, Geobacter sp., and thus the coulombic efficiency was increased. In addition, an electron transfer pathway involving in cytochrome b, OMCs, cytochrome c, and MtrA was proposed based on the cyclic voltammetry analysis. This work will provide a fundamental theoretical support for its application of toxic VOCs abatement from the chemical park.

The permanent wilting point (PWP) is the minimal point of soil moisture a plant requires not to wilt. If moisture decreases to this, or any lower point, a plant wilts, and can no longer recover its turgidity when placed in a saturated atmosphere for 12 h. The PWP is an essential physical property that has a powerful influence on other soil properties and is important for agricultural production, including irrigation water use efficiency and crop yield. However, there are few published datasets on the PWP of cultivated land in the arid and semi-arid regions of Northeast China. Direct measurements of PWP are time-consuming and expensive; therefore, the aim of this study was to evaluate how environmental variables could be used in spatial predictions of PWP in an arid and semi-arid region based on boosted regression tree (BRT) and multiple linear stepwise regression (MLSR) analyses. Seventy soil samples and nine covariates (including topography and vegetation variables) were collected and analyzed. Cross-validation procedure was used to evaluate model performance and uncertainty. Accuracy evaluation results showed that the BRT model had better predictive performance than the MLSR. PWP content decreased from the southwest to the northeast of the study area, and average values of both models were 26%. BRT and MLSR models should be compared and calibrated to obtain the best prediction effect of PWP spatial distribution in similar areas. Elevation, slope gradient, profile curvature, topographic wetness index, and land-use variables are the main environmental indicators that should be included when generating PWP maps of regions with a dry, continental climate. Such information could aid local land managers and government agencies with evaluating soil quality and water sequestration potential. In conclusion, this study could be used as a reference for predicting the hydrological parameters of the topsoil in other similar ecological environments.

Electrochemical hydrogen evolution reactions (HER) have drawn tremendous interest for the scalable and sustainable conversion of renewable electricity to clear hydrogen fuel. However, the sluggish kinetics of the water dissociation step severely restricts the high production of hydrogen in alkaline media. Tuning the electronic structure by doping is an effective method to boost water dissociation in alkaline solutions. In this study, N-doped CoO nanowire arrays (N-CoO) were designed and prepared using a simple method. X-ray diffraction (XRD), element mappings and X-ray photoelectron spectroscopy (XPS) demonstrated that N was successfully incorporated into the lattice of CoO. The XPS of Co 2p and O 1s suggested that the electronic structure of CoO was obviously modulated after the incorporation of N, which improved the adsorption and activation of water molecules. The energy barriers obtained from the Arrhenius relationship of the current density at different temperatures indicated that the N-CoO nanowire arrays accelerated the water dissociation in the HER process. As a result, the N-CoO nanowire arrays showed an excellent performance of HER in alkaline condition. At a current density of 10 mA cm−1, the N-CoO nanowire arrays needed only a 123 mV potential, which was much lower than that of CoO (285 mV). This simple design strategy provides some new inspiration to promote water dissociation for HER in alkaline solutions at the atomic level.

Recovering Cr(III) from chromium-containing waste (CCW) is considered to be a friendly way to protect environment. In this paper, the recovery of Cr(III) from CCW is achieved, via alkali incineration (NaOH and Na2CO3), followed with leaching process using HCl. Firstly, it is demonstrated that there is a large amount of organic matters (oxygen-containing functional groups contained in collagen) in CCW, charactering with Infrared spectrophotometry (FT-IR), Thermogravimetric analysis (TGA) and X-ray photoelectron spectroscopy (XPS). Furthermore, density functional theory (DFT) simulation method is carried out to study the inhibitory behavior of organic matters on recovery of Cr(III). Through geometric optimization, binding energy calculation and a series of electronic structure analysis, the influence of organic matters are analyzed in detail. According to the calculation results, it is clarified that the inhibition mechanism of organic matters on Cr(III) is mainly contributing by forming covalent bond and -OH exhibits greater inhibiting effect than -COOH. In this examine, the related factors are also investigated to reduce the amount of organic matters that is destroyed, including extractant species, alkali dosage, acid dosage and acid concentrations. Finally, the recovering efficiency of Cr(III) is greatly enhanced (95.83%), associated with optimized factors in the process.

Manures, storages for antibiotic resistance genes (ARGs), pollute soil and water as well as endanger human health. Recently, we have been searching a better solution to remove antibiotics and ARGs during aerobic composting. Here, the dynamics of chitosan addition on the profiles of 71 ARGs, bacterial communities, chlortetracycline (CTC), ofloxacin (OFX) were investigated in chicken manure composting and compared with zeolite addition. Chitosan addition effectively reduces antibiotics contents (CTC under detection limit, OFX 90.96%), amounts (18) and abundance (56.7%, 11.1% higher than zeolite addition) of ARGs and mobile genetic elements (MGEs) after 42 days composting. Network analysis indicated that a total of 27 genera strains assigned into 4 phyla (Firmicutes, Proteobacteria, Actinobacteria and Bacteroidetes) were the potential hosts of ARGs. Redundancy analysis (RDA) demonstrated that bacterial community succession is the main contributor in the variation of ARGs. Overall, chitosan addition may effect bacterial composition by influencing physic-chemical properties and the concentration of antibiotics, Cu2+, Zn2+ to reduce the risk of ARG transmission. This study gives a new strategy about antibiotics and ARGs removal from composting on the basis of previous studies.

It has been predicted that the precipitation and atmospheric nitrogen (N) deposition will increase in northern China. Though a variety of publications have documented the effects of increased precipitation and N deposition on aboveground plant community, the responses of soil microbial community composition and function to these possible global changes still remain largely unknown. In this study, we take advantage of a long-term (9-year) field experiment that was established in a typical steppe in Inner Mongolia, China. The responses of microbial community composition and soil enzymatic activities to simulated N deposition and increased precipitation were examined. It was found that the low level of N addition showed no influence on the relative abundance of bacteria, but the relatively high N deposition increased the relative abundance of bacteria. The increased precipitation in combination with N addition, estimated at all N levels, significantly decreased the relative abundance of fungi and fungi/bacteria ratio. Increased precipitation played important roles in enhancing microbial activity in this semi-arid region. It was observed that water supply increased the activities of the five of the enzymes determined, including peroxidase (PER), polyphenol oxidase (PPO), β-Glucosidase (BG), protease (PRO) and alkaline phosphomonoesterase (alkaline PME). The activity of cellulase was reduced by long-term increased precipitation treatment, but was stimulated by simulated N deposition, which may due to the changes in litter components under projected climate change. The influences of N deposition on the microbial enzymatic activities might be alleviated (such as PER), strengthened (acid PME), or not affected by the projected precipitation increment. We also found that the overall changes in soil enzymatic activity patterns are more sensitive to environmental changes than the variations in soil microbial community composition, which may be explained by the microbial function redundancy and the limitations of research method. By all accounts, in future scenarios of increased precipitation in combination with N deposition, the proportion of soil fungi would be reduced, and the microbial community composition might be shifted to be bacteria-dominant. We also predicted that with the increasing of N deposition level, the activities of cellulolase would be enhanced, whereas the activities of ligninolytic enzymes (PER and PPO) would be reduced sharply.

In this work, a facile and general three-step one-pot synthesis of structurally new (E)-6-chloro-2-(aryl/hetarylvinyl)quinoline-3-carboxylic acid derivatives has been achieved from easily available ethyl 6-chloro-2-(chloromethyl) quinoline-3-carboxylate and aromatic or heteroaromatic aldehydes. This strategy features simple one-pot operation, tolerance of a wide range of substituents, and good yields. Moreover, these newly synthesized compounds belong to a new class of quinoline derivatives and could be good candidates for the development of more complex quinoline compounds for use in medicinal chemistry.

The aim of this study was to evaluate the interactive effect of irrigation and nitrogen fertilization on yield, nitrogen (N) uptake, and recovery of two successive Chinese cabbage (Brassica campestris L.) crops and to assess the residue effects of N on the 2nd season crop under greenhouse conditions. 15N-labeled urea was administered to pot-grown Chinese cabbage in the 1st season. The cabbage plants were subjected to three irrigation treatments, 60 (W1), 75 (W2), and 90% (W3) of the soil field capacity, and four N rates, 0 (N0), 0.1 (N1), 0.2 (N2), and 0.3 (N3) g N kg−1 soil. The highest yield, dry matter (DM), N uptake, %Ndff (the percentage of N derived from fertilizer), N recovery rate, and the lowest loss rate were recorded in W3 treatment. N1 treatment had the maximum values for yield, DM, N recovery rate, and the lowest N loss rate. The highest %Ndff was recorded in N2 treatment, with no significant difference observed compared to N3 treatment in the 1st season. In addition, no significant difference among the N rates was observed in the 2nd season. Besides, roots exhibited higher %Ndff values than leaves. Only 5.30–23.00% fertilizer was absorbed by the Chinese cabbage, 56.22–71.29% remained in the soil, and 13.17–37.10% was presumably lost in the 1st season. The recovery rate in the 2nd season was approximately 3.51–17.40%. Therefore, in terms of yield, nitrogen recovery, and environmental impact, W3N1 treatment was recommended as the best combination for Chinese cabbage production and this treatment showed a productive potential in the 2nd season, as well.

Here we investigated the effects of P compounds (KH2PO4 and Ca(H2PO4)2) with different addition rates of 0, 20, 40, 60, 80, and 100 kg P ha−1 yr−1 and NH4NO3 addition (0 and 100 kg N ha−1 yr−1) on soil labile inorganic phosphorus (IP) (dicalcium phosphate, Ca2-P), moderate-cycling IP, and recalcitrant IP fractions in a calcareous grassland of northeastern China. Soil moderate-cycling IP fractions, not readily available to plants but transforming into soil-available P quickly, include variscite (Al-P), strengite (Fe-P) and octacalcium phosphate (Ca8-P); recalcitrant IP fractions include hydroxylapatite (Ca10-P) and occluded P (O-P). Soil labile and moderate-cycling IP fractions and total P significantly increased with increasing P addition rates, with higher concentrations detected for KH2PO4 than for Ca(H2PO4)2 addition. Combined N and P treatments showed lower soil labile IP and moderate-cycling IP fractions compared to ambient N conditions, due to enhanced plant productivity. Moderate-cycling IP was mainly regulated by P addition and plant P uptake to further enhance labile IP and total P concentrations with KH2PO4 and Ca(H2PO4)2 addition. Soil labile IP was also directly and negatively affected by soil pH and plant P uptake with Ca(H2PO4)2 addition. Ca(H2PO4)2 addition significantly increased the soil recalcitrant IP (Ca10-P) fraction, while KH2PO4 addition showed no impact on it. A significant positive correlation was detected between soil labile IP, moderate-cycling IP fractions and soil Olsen-P which illustrated that labile IP and moderate-cycling IP fractions were important sources for soil-available P. Our results suggest that moderate-cycling IP fractions are essential for grassland P biogeochemical cycling and the chemical form of P fertilizer should be considered during fertilization management for maintaining soil-available P.

Carotenoids are ubiquitous constituents of living organisms. These structurally diverse pigments have received considerable attention due to their biotechnological applications and potential beneficial effects on human health. In this study, we characterized an over-producing β-carotene mutant of Sporidiobolus pararoseus, obtained by ultraviolet mutagenesis, named MuY9. We compared the transcriptome between the wild-type and MuY9. A total of 348 differential expressed genes (DEGs) were found, and only one DEG crtYB is involved in carotenoid biosynthesis. The overproduction of β-carotene in MuY9 should be attributed to the up-regulation of crtYB. Functional identification of crtYB was performed using heterologous complementation in Escherichia coli. Our findings indicate that the enzymatic conversions of geranylgeranyl pyrophosphate to phytoene, as well as lycopene to β-carotene, are catalyzed by this CrtYB. Furthermore, our insights into the crtYB gene should facilitate a more detailed understanding of the carotenogenic pathway in S. pararoseus, and advance the development of the genetic engineering for the bio-production of carotenoids.

Attaining greater crop productivity to feed the increasing population while minimizing the unwanted environmental consequences is challenging for nitrogen (N) management. Coated controlled-release urea (CRU) has been widely recommended in recent decades for improving crop productivity and reducing reactive N (Nr) losses. However, the overall effects of CRU application on crop productivity, soil N transformations and N losses to the environment remain unclear. It is also unclear whether the overall benefit of CRU, including reducing N’s environmental impact and increasing crop yield, could offset or even outweigh the application cost. Thus, we conducted a global meta-analysis using 85 publications across the world to assess the above issues. We found that on average, compared to conventional urea application, CRU application significantly increased crop yield and crop N uptake by 7.7% and 12.6%, respectively. Moreover, Nr losses in the form of ammonia (NH3) volatilization, nitrous oxide (N2O) emissions and N leaching were significantly reduced by 24.3–45.9%, mainly due to the relatively slow and continuous N substrate supply from the CRU application. The cost-benefit analysis indicated that the overall benefit outweighed the CRU application cost, producing a net monetary benefit of $117.0 ha-1 that was equivalent to an increase of 6.4% in revenue. Our results highlighted that the positive effect of CRU application on crop productivity and ecosystem services achieved a win-win scenario that, unlike the enhanced NH3 volatilization by nitrification inhibitors, resolved various N-loss dilemmas while increased the economic outcome.

To enhance the nitrogen use efficiency and minimize the use of petrochemical products in coated urea while control the release rate, a novel bio-based coated urea (BCU) was developed using liquefied spent mushroom substrate derived polyurethane. Both nano-SiO2 and 1H, 1H, 2H, 2H-perfluorodecyltriethoxysilane (FAS) were used to modify the BCU to prepare a hydrophobic BCU (SBCU) for improving the water resistant and N release properties. Chemical composition and morphological properties were determined to explain the formation mechanism of the hydrophobic structures. Water absorption and water contact angles (WCAs) were used to evaluate the hydrophobic performance of the coated shells. The nutrient release experiments in water and soil were also conducted to explore the nutrient release characters of the coated urea. The results showed that nano-SiO2 and FAS modified bio-based polyurethane coated urea was successfully fabricated with better release characters. Nutrient released longevity of SBCU reached more than 28 days while that of BCU was only about 5 days. Therefore, findings from this work not only demonstrated the synthesis and application of bio-based petrochemical materials for coated urea but also showed the great potential of a sustainable development of industry for spent mushroom substrate in modern agriculture.

Newly designed ordered two dimensional hexagonal bi-functionalized mesoporous organosilica material (b-MPOS) has been synthesized through the step-by-step post-grafting synthetic pathway. The pure calcined SBA-15 was subjected for functionalization using chloro-substituted organo-silica ligand to get MPCFOS, denoted by mesoporous chloro-functionalized organosilica material. This material undergoes through the substitution reaction (SN2) between the pore wall attached chloro-functional group and the organic bi-functionalized ligand i.e. 3-Amino-1,2,4-triazole-5-carboxylic acid containing amine group in the presence of potassium carbonate which was used as a mild base under the refluxing conditions. The as-synthesized bi-functionalized material displays the high specific surface area as well as pore diameter of 537 m2 g−1 and 9.4 nm, respectively. Since, as-synthesized material contains both acid and basic functional groups, temperature programmed desorption (TPD) of NH3 and CO2 analysis, have been performed to determine the total amount of surface acidic and basic sites of this material which are estimated to be 1.87 and 2.07 mmol g−1, respectively. Due to the presence of Bronsted acid and base groups together with the bi-functionalized material, it has been investigated as a heterogeneous catalyst for carbohydrates transformation to synthesize the valuable chemical like 5-hydroxymethylfurfural (HMF) from fructose with the high product yield of 86 mol% by using microwave irradiated heating conditions.

To enhance the performance of water-based polymer-coated fertilizers and to minimize the environmental pollution caused by fertilizer overuse, a series of nano-SiO2 and water-based polymer were used to fabricate nano-modified water-based polymer-films (NW) at various temperatures and for various reaction times. Both nano-SiO2 and 1H,1H,2H,2H-perfluorooctyltriethoxysilane were used to modify the water-based polymer to prepare a biomimetic hydrophobic water-based polymer (BW) film. Water absorption, water contact angles (WCAs) and permeability experiments were used to evaluate the hydrophobic performance of films. The mechanical, chemical composition and morphological properties were determined and compared to explain the formation mechanism of the hydrophobic structures. A soil leaching test was also conducted to evaluate the nitrogen (N)-release characteristics of the coated urea. This study demonstrated that after modification, the water absorbency was decreased from 150.2 % to 21.4 %, the WCAs and tensile strength (TS) were increased from 33.3° to 120.9° and 26.21 kPa to 36.72 kPa, respectively. The urea coated with BW8 coating material exhibited an excellent release behavior of 87.52 % on the 56th day. Therefore, our work highlights the substantial potential of biomimetic hydrophobic water-based polymer coated urea (BCU) for modern agriculture.

Carotenoids are one of the most common classes of natural pigments widely occurring within organisms. These structurally diverse pigments are of great importance in different processes such as nutrition, vision, cellular growth and development. While found in various yeast strains, one of the best-studied carotenoid producer is the pigmented species Sporidiobolus pararoseus. However, the precise nature of the genes involved in the biosynthesis of carotenoids in this species remains unclear. Here, we cloned a cDNA copy of the phytoene desaturase gene crtI from Sporidiobolus pararoseus CGMCC 2.5280. The crtI full-length genomic DNA and cDNA are 2330bp and 1683bp, respectively. This gene encodes a 560-amino acid protein with a predicted molecular mass of 62.28 kDa and a pI of 7.27. Functional identification of the gene was performed using heterologous complementation detection in Escherichia coli. Our experimental findings indicate that the enzymatic conversion of phytoene to lycopene (fourth step product) and 3,4-didehydrolycopene (fifth step product) is catalyzed by this phytoene desaturase of S. pararoseus through consecutive dehydrogenation. Furthermore, our findings suggest that the crtI gene of S. pararoseus represents an alternative gene source for the reconstruction of carotenogenic pathways vital for the production of engineered carotenoids.

Paddy soil from a site in northeast China was incubated with 13C-labeled rice straw in a laboratory study, and the effects of soil temperature and moisture on CO2 and CH4 emissions were measured using stable isotope ratio mass spectrometry. Aerobic incubation experiments were conducted at three soil temperatures (−10 °C, 0 °C, and 10 °C) and two soil moistures (60% and 100% water-filled pore space (WFPS)) in a laboratory for 24 weeks to simulate the rice-fallow season. An anaerobic incubation experiment was carried out for 16 weeks under a soil temperature of 25 °C and a 1 cm submerged layer to simulate the rice-growing season. Our results showed that increases in both soil temperature and soil moisture significantly promoted the cumulative CO2 emissions from rice straw during aerobic incubation. Furthermore, during anaerobic incubation, the cumulative emissions of CO2 and CH4 from rice straw decreased with increasing aerobic incubation soil temperature and soil moisture. The CO2 and CH4 emission ratios from rice straw throughout the incubation duration ranged from 6.6–15.7% and 0.0–3.0%, respectively. The addition of rice straw promoted a priming effect on native soil organic carbon (SOC) mineralization and produced CO2 emissions, which positively impacted priming during the aerobic (rice-fallow season) and anaerobic incubation (rice-growing season). The positive priming effect of rice straw on the CO2 emission duration ranged from 75.0% to 274.3% by the end of the 40-week incubation period. Furthermore, the aforementioned effect first increased and then decreased as the aerobic incubation soil temperature increased, with the greatest effect at 0 °C and lowest at 10 °C. These results suggest that high temperature during the rice-fallow season promotes the decomposition of rice straw C and leads to a decreased positive priming effect on native SOC during the rice-fallow and rice-growing seasons under the seasonal conditions of northeast China, and that it also leads to decreased CH4 production during the rice-growing season. These results have scientific significance for rational utilization of rice straw and mitigation of greenhouse effect in northeast China.

As an ideal hydrogen supplier in liquid phase, hydrous hydrazine has gained a lot of attention for safe and efficient storage as well as transportation of hydrogen. Herein, a low Pt-containing Ni–Pt bimetallic catalyst immobilized on novel MIL-101/rGO composite has been prepared by a facile impregnation-reduction approach. Unexpectedly, the resultant Ni0.9Pt0.1/MIL-101/rGO catalyst exhibits optimal catalytic performance and 100% H2 selectivity for hydrogen evolution from hydrous hydrazine under alkaline conditions at 323 K, giving a turnover frequency (TOF) value of 960.0 h−1, which is a relatively higher value ever reported heterogeneous catalysts. Even at room temperature, Ni0.9Pt0.1/MIL-101/rGO catalyst shows excellent catalytic activity for dehydrogenation of hydrazine as well as hydrazine borane. In addition, the Ni0.9Pt0.1/MIL-101/rGO catalyst also exhibits excellent durability. Even after eight recycles, the catalytic activity is no significant decrease, and the H2 selectivity still remains 100%.

Inorganic matter modifications were used to improve the hydrophobic properties and slow-release effects of water-based copolymer films. Water-based copolymers were prepared by aqueous polymerization of polyvinyl alcohol, starch, chitosan, and sodium carboxymethyl cellulose, and then, zeolite powder, volcanic ash or biochar were added to prepare the inorganic matter modified water-based copolymer films. The results showed that the inorganic matter modified water-based copolymer films had enhanced thermal stability, reductions in O-H and water vapour permeability, and increased crystallinity and roughness. Compared with water-based copolymer films, the water absorption capacities of the zeolite powder modified water-based copolymer films, volcanic ash modified water-based copolymer films, and biochar modified water-based copolymer films were reduced by 42.8 %, 50.0 % and 39.0 %, and their ammonium permeability was reduced by 53.0 %, 12.1 % and 1.1 %, respectively. Inorganic matter modified water-based copolymer films have properties that make them suitable for use in preparing slow-release coating materials.

The development of highly active, stable, and inexpensive catalysts for efficient and complete dehydrogenation of hydrazine is highly attractive but still very challenging. Herein, Cr2O3-modified NiFe (NiFe-Cr2O3) nanopartciles (NPs) have been designed as the heterogeneous catalyst. Both the catalytic activity and hydrogen selectivity of Ni0.9Fe0.1-Cr2O3 NPs were improved remarkably as compared with those of their mono-metallic counterparts. The prepared Ni0.9Fe0.1-Cr2O3 catalyst exhibited an outstanding catalytic activity to release 3.0 equiv. (H2 + N2) from hydrazine in only 8.5 min at 70 °C, providing a turnover frequency (TOF) value of 893.5 h−1 based on surface metal atoms. Systematic studies indicated that the small size and high surface area of Ni0.9Fe0.1-Cr2O3 as well as the strong synergistic electronic effect between Cr2O3 and NiFe NPs resulted in the excellent activity of Ni0.9Fe0.1-Cr2O3 catalyst. Such a highly rapid, long term durability, and low cost catalyst may encourage greatly the practical application of hydrous hydrazine as a chemical hydrogen storage material.

Carotenoids represent a diverse class of aliphatic C40 molecules with a variety of applications in the food and pharmaceutical industries. Sporidiobolus pararoseus NGR produces various carotenoids, including torulene, torularhodin and β-carotene. Salt stress significantly increases the torulene accumulation of S. pararoseus NGR. However, little is known, about the molecular mechanisms underlying the increased torulene biosynthesis. In this work, we investigated the effects of NaCl treatment on the contents of carotenoids (both qualitatively and quantitatively) and transcriptome. A total of 12.3 Gb of clean bases were generated in six cDNA libraries. These bases were de novo assembled into 9,533 unigenes with an average length of 1,654 nt and N50 of 2,371 nt. Transcriptome analysis revealed that of 3,849 differential expressed genes (DEGs) in response to salt stress, 2,019 were up-regulated, and 1,830 were down-regulated. Among these DEGs, we identified three carotenogenic genes crtE, crtYB, and crtI. In addition, fourteen candidate genes were predicted to participate in the conversion from torulene to torularhodin. Our findings should provide insights into the mechanisms of carotenoid biosynthesis and salt-tolerance of S. pararoseus NGR.

Carotenoids represent a class of molecules valuable for food, chemical and pharmaceutical industries. As a microbial carotenoid, torulene possesses potential health-promoting effects in human. However, few studies have been conducted to investigate optimal condition for its large-scale commercial production to date. Sporidiobolus pararoseus NGR, a pigmented yeast, was shown previously to accumulate considerable amounts of torulene, β-carotene, and torularhodin. In this study, the effect of salt stress on the production of carotenoids in S. pararoseus NGR was investigated. After 5days of cultivation, the total amount of carotenoids was significantly higher in 0.75M (3.952mg/L) and 1M (2.89mg/L) NaCl treatments than control (1.636mg/L), respectively. Among them, the increase in torulene accumulation is the main contributor to the improvement in total amount of carotenoids under 0.75 and 1M NaCl treatments. Together, our results should advance the development of metabolic engineering for the commercial production of torulene.

Background Understanding the nitrogen (N) mineralization process and applying appropriate model simulation are key factors in evaluating N mineralization. However, there are few studies of the N mineralization characteristics of paddy soils in Mollisols area of Northeast China. Materials and methods The soils were sampled from the counties of Qingan and Huachuan, which were located in Mollisols area of Northeast China. The sample soil was incubated under waterlogged at 30°C in a controlled temperature cabinet for 161 days (a 2: 1 water: soil ratio was maintained during incubation). Three models, i.e. the single first-order kinetics model, the double first-order kinetics model and the mixed first-order and zero-order kinetics model were used to simulate the cumulative mineralised N (NH4+-N and TSN) in the laboratory and waterlogged incubation. Principal results During 161 days of waterlogged incubation, the average cumulative total soluble N (TSN), ammonium N (NH4+-N), and soluble organic N (SON) was 122.2 mg kg-1, 85.9 mg kg-1, and 36.3 mg kg-1, respectively. Cumulative NH4+-N was significantly (P < 0.05) positively correlated with organic carbon (OC), total N (TN), pH, and exchangeable calcium (Ca), and cumulative TSN was significantly (P < 0.05) positively correlated with OC, TN, and exchangeable Ca, but was not significantly (P > 0.05) correlated with C/N ratio, cation exchange capacity (CEC), extractable iron (Fe), clay, and sand. When the cumulative NH4+-N and TSN were simulated, the single first-order kinetics model provided the least accurate simulation. The parameter of the double first-order kinetics model also did not represent the actual data well, but the mixed first-order and zero-order kinetics model provided the most accurate simulation, as demonstrated by the estimated standard error, F statistic values, parameter accuracy, and fitting effect. Conclusions Overall, the results showed that SON was involved with N mineralization process, and the mixed first-order and zero-order kinetics model accurately simulates the N mineralization process of paddy soil in Mollisols area of Northeast China under waterlogged incubation.

The effect of different concentrations of natural macromolecular compound on the characteristics of nutrient release in the membrane materials of organic-inorganic compound film-coated urea was discussed, and the optimal concentrations for better nutrient release was proposed. The characteristics of nutrient release of film-coated urea were evaluated by soil column leaching experiment. Organic-inorganic compound film-coated urea showed good characteristics of nutrient release, which could be well simulated by Logistic curve. The two parameters in this curve, a and r, can be used to present nutrient release of film-coated urea, and followed the order of B > C > A and C < B < A, respectively, indicating that the release was stronger with the increasing concentration of natural macromolecular compound in the membrane, which implied better controllability of nutrient release. The concentration of 5% of natural macromolecular compound showed better characteristic of nutrient release and can be utilized as a membrane material combined with inorganic mineral powders to develop film-coated slow-release fertilizer.

Copyright © 2015 Hongtao Zou et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited., A soil incubation method was used to investigate the solubility characteristics and slow-release mechanism of organic-inorganic compound coated urea at temperature of 10, 20, and 30°C. The membrane microstructure with and without incubation was tested via scanning electron microscopy (SEM). Slow release of nitrogen (N) from different inorganic minerals was analysed by the activation energy from the nutrient solubility system. The rate of nitrogen solubility increased with temperature increasing. The first-order reaction kinetic equation described the solubility process of coated urea. The rate constant also increased with temperature increasing. Moreover, the SEM images showed that the microstructure of the coating layer changed into a flocculent structure and the number of tiny pores and holes on the membrane surface increased significantly with temperature increasing, which increased N solubility rate. The Arrhenius equation indicated that activation energy was closely related to during the solubility process; the activation energy was reduced with rising, which resulted in N solubility rate increasing. Overall, the N solubility rate of coated urea was affected by temperature.

Returning straw to deep soil layers by using a deep-ditching-ridge-ploughing method is an innovative management practice that improves soil quality by increasing the soil organic carbon (SOC) content. However, the optimum quantity of straw return has not been determined. To solve this practical production problem, the following treatments with different amounts of corn straw were investigated: no straw return, CK; 400 kg ha-1 straw, S400; 800 kg ha-1 straw, S800; 1200 kg ha-1 straw, S1200; and 1600 kg ha-1 straw, S1600. After straw was returned to the soil for two years, the microbial biomass C (MBC), easily oxidized organic C (EOC), dissolved organic C (DOC) and light fraction organic C (LFOC) content were measured at three soil depths (0-10, 10-20, and 20-40 cm). The results showed that the combined application of 800 kg ha-1 straw significantly increased the EOC, MBC, and LFOC contents and was a suitable agricultural practice for this region. Moreover, our results demonstrated that returning straw to deep soil layers was effective for increasing the SOC content.

Based on experiment of plastic mulching and drip irrigation in greenhouse, nine treatments of different irrigation and fertilization were evaluated with multi-factor fuzzy synthesis evaluation method. Linear function was selected as membership function in fuzzy synthesis evaluation model. The weighting of factors set which included the yield, fruit qualities, water use efficiency and fertilizer utilization efficiency was confirmed by principal component analysis method. The evaluation result showed that the optimum treatment of integral indicators that fertilizer amount was pure N 337.5 kg·ha − 1 and pure K 2 O 337.5 kg·ha − 1, lower and high limit of irrigation were respective 40 kPa and 6 kPa.