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Salt accumulation in bare strips under film-mulched drip irrigation is a global concern as it adversely affects soil quality and hinders sustainable agricultural development in arid and semi-arid regions. This study aims to investigate the spatial distribution of soil moisture and salt under various planting patterns and assess the lateral salt accumulation effect in bare strips. Seven treatments were implemented based on the local cotton planting pattern, including the local classical planting pattern (LTP), mulch width of 220 cm (WFM-220), spacing of 90 cm (SFM-90), mulch width of 40 cm (WFM-40), spacing of 10 cm (SFM-10), ridge tillage (TFM-RT), and ditching (TFM-D), varying in mulch width, spacing, and tillage method in bare strips. Additionally, the performance of the HYDRUS-2D model was evaluated by comparing simulated and observed values using field data. The results revealed that (I) the WFM-220 cm treatment exhibited the best water content retention under mulched film, with lower salt accumulation in the surface bare strip (0–20 cm soil layer); (II) all treatments with narrow rows showed desalination effects in the 0–40 cm soil layer, with salt content reductions ranging from approximately 13% to 38% compared to the initial values; (III) under the LTP treatment, the lateral salt discharge effect in the bare strip of the 0–40 cm soil layer was the best, regardless of mulch width and spacing, with a salt accumulation rate up to three times higher than the initial value, and even up to four times higher in the 0–10 cm layer; (IV) the TFM-RT treatment exhibited the best salt accumulation ability on the surface bare strip; and (V) the HYDRUS-2D model proved to be an effective tool for studying the dynamic regulation mechanism of water and salt with root mean square error values ranging from 0.079 to 0.106 cm3·cm−3 for soil water content and from 0.044 to 0.079 dS·m−1 for electrical conductivity, indicating good agreement between simulations and observations. [ABSTRACT FROM AUTHOR]

Seed germination is a crucial stage in the life cycle of annuals in arid, saline regions and is particularly vulnerable to abiotic stresses. Peganum harmala, a valuable medicinal plant, has limited research on its seed germination response to different environmental stresses in the arid, saline regions of Central Asia. To investigate this, we studied the effects of various temperature regimes (ranging from 20/5 to 35/20 °C), light exposure (12 hours light/12 hours dark and continuous dark), seven levels of polyethylene glycol (PEG-6000) concentration (ranging from 0–30%), and four types of salinity (ranging from 0–600 mmol L−1). Our findings show that photoperiod and temperature significantly influence germination. Optimal temperature range for seed germination was observed at 30/15 °C, with simulated critical and limit values of drought tolerance being highest (17.30% and 24.98%). However, higher temperatures (35/20 °C) and lower temperatures (20/5 °C) reduced the critical and limit values of drought tolerance. Additionally, the type and concentration of salinity had a significant effect on the seed germination, shoot, and root lengths of P. harmala. Regression analysis indicated that the critical values of NaCl, Na2SO4, NaHCO3, and Na2CO3 tolerance during germination were 178 mmol L−1, 101 mmol L−1, 106 mmol L−1, and 54 mmol L−1, respectively. Salinity inhibition on seed germination followed the order: NaCl < NaHCO3 < Na2SO4 < Na2CO3. Moreover, NaCl, Na2SO4, NaHCO3, and Na2CO3 significantly inhibited the growth of P. harmala seedlings in both shoots and roots. Our study demonstrates the sensitivity of P. harmala to environmental factors such as light, temperature, drought, and salinity. The study provides valuable information on the germination ecology of P. harmala under diverse ecological scenarios, which can be useful in developing efficient propagation and utilization of this medicinal plant. [ABSTRACT FROM AUTHOR]

With the increasing shortage of water resources, the current management of saline–alkali lands in semi-arid and arid areas has gradually transformed from "flooding irrigation with drainage" in the past to the combination of controlling regional water and salt balance, phytoremediation, and comprehensive utilization of halophyte resources. However, soil salinization caused by natural and anthropogenic factors has still been a major global environmental problem, which changes the chemical and physical properties of soil, deteriorates the quality of underground water, and decreases biodiversity, contributing to the loss of soil productivity and the succession of the halotolerant species. Euhalophytes, as the materials for phytoremediation, have been confirmed to be effective species in improving saline–alkali soils. They can redistribute salts in soil profile through the interaction of their desalinization potential and irrigation water leaching, thereby preventing secondary salinization and improving soil productivity for long-term reclamation of saline soil. In this review, the adaptation mechanisms of euhalophytes to saline soils are generalized from the views of morphological, physiological, and molecular aspects and evaluated for their potential to remediate saline soil through salt removal and promoting leaching. Euhalophytes can not only sequestrate salts inside the central vacuole of cells to tolerate higher salt stress by means of organ succulence, ion compartmentalization, and osmotic adjustment but facilitate water infiltration and salts leaching through root–soil interaction. The root system's mechanical penetration increases soil porosity, decreases soil density, as well as stabilizes soil aggregates. Moreover, the suitability of phytoremediation in arid situations with low precipitation and non-irrigation and some agricultural practices need to be taken into account to avoid salts returning to the soil as forms of litter and deep tillage altering salt distribution. Hence, euhalophytes planting in semi-arid and arid areas should be evaluated from their adaptation, desalinization, and prospective commercial values, such as foods, biofuels, and medical development to alleviate soil secondary salinization crisis and enhance the productivity of arable agricultural land. [ABSTRACT FROM AUTHOR]

Background The caper bush Capparis spinosa L. one of the most economically important species of Capparaceae, is a xerophytic shrub that is well adapted to drought and harsh environments. However, genetic studies on this species are limited because of the lack of its reference genome. Findings We sequenced and assembled the Capparis spinosa var. herbacea (Willd.) genome using data obtained from the combination of PacBio circular consensus sequencing and high-throughput chromosome conformation capture. The final genome assembly was approximately 274.53 Mb (contig N50 length of 9.36 Mb, scaffold N50 of 15.15 Mb), 99.23% of which was assigned to 21 chromosomes. In the whole-genome sequence, tandem repeats accounted for 19.28%, and transposable element sequences accounted for 43.98%. The proportion of tandem repeats in the C. spinosa var. herbacea genome was much higher than the average of 8.55% in plant genomes. A total of 21,577 protein-coding genes were predicted, with 98.82% being functionally annotated. The result of species divergence times showed that C. spinosa var. herbacea and Tarenaya hassleriana separated from a common ancestor 43.31 million years ago. Conclusions This study reported a high-quality reference genome assembly and genome features for the Capparaceae family. The assembled C. spinosa var. herbacea genome might provide a system for studying the diversity, speciation, and evolution of this family and serve as an important resource for understanding the mechanism of drought and high-temperature resistance. [ABSTRACT FROM AUTHOR]

Halophytes are capable of resisting salinity, and their root system is the part in direct contact with the saline soil environment. The aim of this study was to compare the responses of root morphology and rhizosphere characteristics to salinity between a halophyte, Suaeda salsa (suaeda), and a glycophyte, Beta vulgaris L. (sugar beet). The soil salt content was set to four levels (0.7, 1.2, 1.7, and 2.7%) by NaCl-treated plants. We investigated the soil pH, EC, nutrients and soil, plant ion (Na+, Cl−, K+, and Mg2+) concentration to evaluate the rhizospheric processes, and salt tolerance of suaeda by the root mat method. The highest biomass was in the 1.2% salt level for suaeda and in the 0.7% salt level for sugar beet. The root length and root surface area of suaeda showed similar trends to biomass, but the root diameter decreased by 11.5–17.9% with higher salinity. The Na+, Cl−, and K+ accumulations in the shoot of suaeda displayed higher than that in sugar beet, while the Mg2+ accumulation was lower in suaeda than that in sugar beet. High salinity resulted in increased pH and EC values in the rhizosphere for suaeda, but lower values of these parameters for sugar beet. Under high salinity, the Olsen phosphorus content was 0.50 g·kg−1 and 0.99 g·kg−1 higher in the rhizosphere than in the non-rhizosphere for suaeda and sugar beet. We concluded that the two species [halophyte, Suaeda salsa (suaeda), and a glycophyte, B. vulgaris L. (sugar beet)] showed diverse approaches for nutrient absorption under salinity stress. Suaeda altered its root morphology (smaller root diameter and longer roots) under salt stress to increase the root surface area, while sugar beet activated rhizospheric processes to take up more nutrients. [ABSTRACT FROM AUTHOR]

The period between seed germination and seedling establishment is one of the most vulnerable stages in the life cycle of annuals in the saline environments. Although germination characteristics of Suaeda salsa seeds have been reported, the comparative germination patterns of dimorphic seeds and seedling growth to different abiotic stresses remain poorly understood. In this study, germination responses of dimorphic seeds to light and temperature were compared. Meanwhile, responses of dimorphic seeds and thereafter seedlings of S. salsa to different concentrations of NaCl and Na2SO4 were also tested. The results showed that the light did not significantly affect germination percentage of brown seeds, but significantly promoted germination of black seeds. Brown seeds could reach high germination percentage over a wide temperature range, however, germination of black seeds gradually increased with the increase of temperature. Brown seeds had higher germination percentage and velocity than black seeds under the same salt conditions. However, black seeds had higher recovery germination than brown seeds when transferred to deionized water. Young seedlings had lower salt tolerance than germinating seeds. At the same concentrations, Na2SO4 had stronger inhibitory effect on seed germination and seedling growth than NaCl. This study comprehensively compared germination traits of dimorphic seeds and seedling growth of S. salsa , and then developed a conceptual model to explain their adaptation to harsh saline environment. [ABSTRACT FROM AUTHOR]

In this paper, a new electromagnetic acoustic resonance (EMAR) transducer is proposed for precise thickness measurement in specimen. The new EMAR is composed of a mirror symmetric coil (MSC) and a pair of Nd-Fe-B permanent magnets with the different polarity for enhancing the generation and detection of resonant signals. Firstly, a finite element model was established to simulate the distributions of Lorentz force produced by new EMAR and the resonant process of shear waves. Furthermore, the relationship between the frequency response characteristic of the new EMAR and the common EMAR were explored. Finally, to verify the performance of the EMAR, several experiments were performed. Compared with the common EMAR transducer, the resonant amplitude of the new EMAR transducer was increased by 121.74% and the signal-to-noise ratio was increased by 28.35%, and the resonance frequency interval of the new EMAR was twice that of the common mode in the frequency domain simulation experiment, this advantage effectively reduced the error rate of measurement. The results show that the new EMAR transducer with mirror coil structure has higher accuracy in thickness detection of specimens. [ABSTRACT FROM AUTHOR]

During composting, the thermophilic phase resulted in high degradation of antibiotics in the composting mass; thus temperature is considered as the major factor for degradation of antibiotics. Therefore, to achieve complete removal of antibiotics, the effect of continuous thermophilic composting on the degradation of antibiotics and their effect on antibiotic resistant bacteria in the pig manure were evaluated. Pig manure was mixed with sawdust, spiked with tetracycline (10 and 100 mg/kg) and sulfadiazine (2 and 20 mg/kg) on dry weight (DW) basis and composted at 55°C for six weeks. Based on the organic decomposition, the antibiotics did not affect the composting process significantly, but negatively influenced the bacterial population. Tetracycline clearly exhibited a negative but marginal influence on carbon decomposition at 100 mg/kg level. The bacterial population initially decreased steeply ∼2 logs and slowly increased thereafter. Sulfadiazine and tetracycline resistant bacterial populations were stable/marginally increased after an initial decrease of about 2 or 3–5 logs, respectively. Sulfadiazine was not detectable after three days; whereas, ∼8% of tetracycline was detected after 42 days of composting with at1/2of ∼11 days, irrespective of the initial concentration. The presence of tetracycline in the compost after 42 days of thermophilic composting indicates the involvement of a mesophilic microbial-mediated degradation; however, further studies are required to confirm the direct microbial involvement in the degradation of antibiotics. [ABSTRACT FROM PUBLISHER]

Halophytes possess the capacity to uptake high levels of salt through physiological processes and their root architecture. Here, we investigated whether halophyte/non-halophyte intercropping in saline soil benefits plant growth and contains root-dialogue between interspecific species. Field and pot experiments were conducted to determine the plant biomasses and salt and nutrient distributions in three suaeda (Suaeda salsa)/maize (Zea mays L.) intercropping systems, set up by non-barrier, nylon-barrier, and plastic-barrier between plant roots. The suaeda/maize intercropping obviously transferred more Na+ to the suaeda root zone and decreased salt and Na+ contents. However, the biomass of the non-barrier-treated maize was significantly lower than that of the nylon and plastic barrier-treated maize. There was lower available N content in the soil of the non-barrier treated groups compared with the plastic barrier-treated groups. In addition, the pH was lower, and the available nutrient content was higher in the nylon barrier, which suggested that rhizospheric processes might occur between the two species. Therefore, we concluded that the suaeda/maize intercropping would be beneficial to the salt removal, but it caused an adverse effect for maize growth due to interspecific competition, and also revealed potential rhizospheric effects through the role of roots. This study provides an effective way for the improvement of saline land. [ABSTRACT FROM AUTHOR]

Abattoir blood meal is rich in nitrogen and its potential as a co-composting material for horse stable bedding waste was evaluated at two C/N ratios – 32 (LBM, low blood meal) and 16 (HBM, high blood meal) – to improve the nutrient contents of the final compost. The mix was composted for 7 days in a 10 tonne/day in-vessel composter and cured aerobically. After 56 days of composting, the ammoniacal-N, CO 2 evolution rate and C/N ratio of both LBM and HBM were within the guideline values; however, delayed decomposition and lower seed germination index were observed with HBM. In addition, HBM resulted in 84% loss of the initial ammoniacal-N. Almost similar organic decompositions, 62.4% and 59.6% with LBM and HBM, respectively, were achieved. However, a stable compost product can be obtained within 6–7 weeks with LBM, whereas>8 weeks were required for HBM composting. Therefore, co-composting at the C/N ratio of 32 is recommended to achieve odour-free and faster composting. [ABSTRACT FROM PUBLISHER]

Soil contaminated by organic pollutants, especially chlorinated aromatic compounds such as DDT (1,1,1-trichloro-2,2-bis(4-chlorophenyl)ethane), is an environmental concern because of the strong sorption of organochlorine pesticide onto the soil matrix and persistence in the environment. The remediation of organochlorine pesticide contaminated soils through microemulsion is an innovative technology to expedite this process. The remediation efficiency was evaluated by batch experiments through studying the desorption of DDT and hexachlorocyclohexane (γ-HCH) and sorption of microemulsion composed of Triton X-100, 1-pentanol and linseed oil in the soil–surfactant–water suspension system. The reduction of desorption efficiency caused by the sorption loss of microemulsion components onto the soil could be corrected by the appropriate adjustment of C/S (Cosurfactant/Surfactant) and O/S (Oil/Surfactant) ratio. The C/S and O/S ratios of 1:2 and 3:20 were suitable to desorb DDT and γ-HCH from the studied soils because of the lower sorption of Triton X-100 onto the soil. Inorganic salts added in microemulsion increased the pesticides desorption efficiency of pesticides and calcium chloride has a stronger ability to enhance the desorption of DDT than sodium chloride. From the remediation perspective, the balance of surfactant or cosurfactant sorbed to soil and desorption efficiency should be taken into consideration to enhance the remediation of soils contaminated by organochlorine pesticides. [ABSTRACT FROM PUBLISHER]

Composting sewage sludge alone would reduce the decomposition efficiency due to free limited porosity in sludge. To alleviate this, the use of horse stable straw bedding waste (HSB) was evaluated as a co-composting material with sewage sludge in a 10 tonnes day−1 in-vessel composter for a period of 7 days before curing in a static aeration pile. Sludge was mixed with HSB at 1 : 1.5 (HSL) and 1 : 2.9 (LSL) on a fresh weight basis. After a composting period of 56 days, both mixing ratios demonstrated to be feasible with LSL having a better organic decomposition and a shorter time to reach maturity. The overall decomposition rates were 52.0 and 58.9% (dry weight basis) for HSL and LSL, respectively. In both treatments, temperature in the in-vessel composters could reach 65°C, which was sufficient to remove the pathogens. Although both products were free of pathogens, HSL exhibited a higher ammoniacal nitrogen contents but a lower seed germination index than that of LSL indicating a higher phytotoxicity and a longer curing period would be required. It can be concluded that HSB provided a better composting conditions at a mixing ratio of 1 : 2.9 [ABSTRACT FROM AUTHOR]

Abstract: The effects of rhamnolipids produced by Pseudomonas aeruginosa ATCC9027 on the cell surface hydrophobicity (CSH) and the biodegradation of phenanthrene by two thermophilic bacteria, Bacillus subtilis BUM and P. aeruginosa P-CG3, and mixed inoculation of these two strains were investigated. Rhamnolipids significantly reduced the CSH of the hydrophobic BUM and resulted in a noticeable lag period in the biodegradation. However, they significantly increased the CSH and enhanced the biodegradation for the hydrophilic P-CG3. In the absence of rhamnolipids, a mixed inoculation of BUM and P-CG3 removed 82.2% of phenanthrene within 30days and the major contributor of the biodegradation was BUM (rapid degrader) while the growth of P-CG3 (slow degrader) was suppressed. Addition of rhamnolipids promoted the surfactant-mediated-uptake of phenanthrene by P-CG3 but inhibited the uptake through direct contact by BUM. This resulted in the domination of P-CG3 during the initial stage of biodegradation and enhanced the biodegradation to 92.7%. [Copyright &y& Elsevier]

Two thermophilic bacterial strains, Bacillus subtilis BUM (BUM) and Mycobacterium vanbaalenii BU42 (BU42), were tested for their potential in biodegradation of benzo[a]pyrene. Neither BUM nor BU42 utilized benzo[a]pyrene as the sole substrate under thermophilic condition. In the presence of 50, 250, and 500 mg L−1 phenanthrene, the biodegradation of benzo[a]pyrene by BUM occurred and removals in 30 days were 14.8%, 38.8%, and 63.6%, respectively. This is the first report on the biodegradation of benzo[a]pyrene by isolated thermophilic microorganism. The BUM strain was further tested for its ability in a soil composting system. Within a composting period of 42 days, removal of benzo[a]pyrene in the absence of BUM was 30.3%. Treatment with the inoculation of BUM significantly increased the removal of benzo[a]pyrene to 52.2%. Maximum zero-order degradation rates of benzo[a]pyrene by BUM in aqueous biodegradation experiment and soil composting system were 12.3 mg L−1 day−1 and 9.7 mg kg−1 day−1, respectively, which were significantly greater than most of the reported degradation rates by mesophiles. Experimental results affirmed that the strain BUM can effectively degrade benzo[a]pyrene under thermophilic condition. [ABSTRACT FROM AUTHOR]

Water conditions directly affect plant growth and thus modify reproduction allocation. However, little is known about the transgenerational effects of water conditions on xerophytes. The desert annual Atriplex aucheri produces three types of seeds (A: dormant, ebracteate black seeds; B: dormant, bracteolate black seeds; C: non-dormant, bracteolate brown seeds) on a single plant. The aim of this study was to investigate the effects of low/high water treatment (thereafter progeny water treatment) on aboveground biomass, C:N stoichiometry, and offspring seed characteristics of A. aucheri grown from brown seeds whose mother plants were under low/high water treatment (thereafter maternal water treatment). Progeny water only affected shoot dry weight and seed allocation of type A. Under low progeny water treatment, plants from parents with low maternal water treatment had the lowest biomass. Maternal water did not significantly influence the C and N content, however high maternal water increased the C:N ratio. Maternal water treatment did not significantly affect seed number. However, plants under low maternal and progeny water treatments had the lowest weight for type B seeds. When progeny plants were under low water treatment, seed allocation of type A, type B, and total seed allocation of plants under high maternal water were significantly lower than those of plants under low maternal water. These results indicate that water conditions during the maternal generation can dramatically contribute to progeny seed variation, but the transgenerational effects depend on the water conditions of progeny plants. [ABSTRACT FROM AUTHOR]

Excessive application of nitrogen fertilizers and improper methods of irrigation under conventional management are common problems in the cotton fields of northwestern China. Efficiency-enhanced management, based on the water and nitrogen dynamics and crop requirements, has been used as a valuable strategy in different crops. The present study aimed to compare efficiency-enhanced management and conventional management of irrigation and nitrogen fertilization in the cotton fields at the Junggar Basin (Shihezi) and Tarim Basin (Cele) of northwestern China. Compared with conventional management, efficiency-enhanced management reduced the amount of N fertilizer by 41% in Cele and 44% in Shihezi, and the irrigation quantity by 35% in Cele and 24% in Shihezi. However, the cotton yield under efficiency-enhanced management was similar to that found under conventional management at both the experimental sites. The efficiency-enhanced management increased the water-use efficiency (WUE) and reduced the residual soil mineralizable N (Nmin) and apparent N losses. This study indicated that efficiency-enhanced management can significantly enhance the utilization efficiency of irrigation water and N fertilizers for cotton production in the fields of northwestern China. [ABSTRACT FROM AUTHOR]

Euhalophytes, such as Suaeda salsa, are ideal candidates to remediate heavy metal-polluted saline soils. However, the metal tolerance ability of dimorphic seeds and subsequent seedlings is largely unknown. This study investigated the tolerance of S. salsa seeds to different concentrations of Cu2+ (0–300 mM) and Zn2+ (0–300 mM) during germination and seedling growth stages. Results showed that dimorphic seeds of S. salsa had high metal tolerance during germination, and even germinated under 300 mM Cu and Zn treatments. However, seedling growth was more sensitive to metal solutions and radicle growth was almost completely inhibited by Cu at 10 mM, and by Zn at 50 mM. Germinating seeds and seedlings of S. salsa had a higher metal toxicity threshold of Zn than that of Cu. In all indexes, indexes of radicle were the most sensitive and effective indicator of metal tolerance. Seeds of S. salsa germinated successfully and seedlings survived under high Zn and Cu stress. The results suggest that S. salsa could be sown directly in heavy metal-contaminated soils for phytoremediation. [ABSTRACT FROM AUTHOR]

Background The halophyte Suaeda aralocaspica performs complete C4 photosynthesis within individual cells (SCC4), which is distinct from typical C4 plants, which require the collaboration of 2 types of photosynthetic cells. However, despite SCC4 plants having features that are valuable in engineering higher photosynthetic efficiencies in agriculturally important C3 species such as rice, there are no reported sequenced SCC4 plant genomes, limiting our understanding of the mechanisms involved in, and evolution of, SCC4 photosynthesis. Findings Using Illumina and Pacific Biosciences sequencing platforms, we generated ∼202 Gb of clean genomic DNA sequences having a 433-fold coverage based on the 467 Mb estimated genome size of S. aralocaspica. The final genome assembly was 452 Mb, consisting of 4,033 scaffolds, with a scaffold N50 length of 1.83 Mb. We annotated 29,604 protein-coding genes using Evidence Modeler based on the gene information from ab initio predictions, homology levels with known genes, and RNA sequencing–based transcriptome evidence. We also annotated noncoding genes, including 1,651 long noncoding RNAs, 21 microRNAs, 382 transfer RNAs, 88 small nuclear RNAs, and 325 ribosomal RNAs. A complete (circular with no gaps) chloroplast genome of S. aralocaspica 146,654 bp in length was also assembled. Conclusions We have presented the genome sequence of the SCC4 plant S. aralocaspica. Knowledge of the genome of S. aralocaspica should increase our understanding of the evolution of SCC4 photosynthesis and contribute to the engineering of C4 photosynthesis into economically important C3 crops. [ABSTRACT FROM AUTHOR]

This article has been retracted: please see Elsevier Policy on Article Withdrawal ( http://www.elsevier.com/locate/withdrawalpolicy ). This article has been retracted at the request of Editor-in-Chief Marisol Berti in agreement with Editor-in-Chief Maria Jesus Pascual Villalobos. The article has been retracted due to ‘salami slicing publication’. Part of apparently the same study was submitted 10 days earlier and published in Industrial Crops and Products 95(1) (2017) 156-162. ( http://dx.doi.org/10.1016/j.indcrop.2016.09.049 ). The authors accepted this decision and apologized for the trouble caused. As a consequence, pages 42-45 originally occupied by the retracted article are missing from the printed issue. The publisher apologizes for any inconvenience this may cause. [ABSTRACT FROM AUTHOR]

Optimization of nitrogen fertilizer application is an important means of improving castor ( Ricinus communis L.) yield. The method of nitrogen application with drip irrigation under mulch film (DI) differs from that of standard cultivation practices. A field experiment was conducted in 2013 and 2014 to investigate the effects of different nitrogen treatments (0, 100, 200, 300, and 400 kg N ha −1 ) on castor yield, nitrogen use efficiency, and dynamic changes in the spatial distribution of roots under DI. The main objective was to determine the effectiveness of nitrogen fertilizer application for simultaneous improvement of the nitrogen use efficiency and productivity of castor. Yield showed a distinct increase with elevation in nitrogen application rate. The highest yields of 5939.3 and 5812.1 kg ha −1 were attained under nitrogen application of 300 kg N ha −1 in the 2013 and 2014 cropping seasons, respectively. However, application of 400 kg N ha −1 did not further increase yield. Root length increased gradually with increasing nitrogen application from 0 to 200 kg N ha −1 . Under 200 kg N ha −1 , maximum root length was observed and the root length density in the soil was most widely distributed in the entire soil profile, which may account for the high nitrogen use efficiency observed in this treatment (72.4% and 67.4% in 2013 and 2014, respectively). The difference in yield between the 300 kg N ha −1 and 200 kg N ha −1 treatments was not significant. The results suggest that the optimal nitrogen application for castor under DI is between 200 and 300 kg N ha −1 to improve yield and nitrogen use efficiency simultaneously. [ABSTRACT FROM AUTHOR]

• Apocynum is widely distributed and geographically diverse plant species. • Apocynum exhibits several medical and economic benefits. • Salt tolerance in Apocynum is associated with better redox- and osmo-regulation. • Apocynum can be used to remediate saline area due to its better ability to remove salts from soil and sequester in leaves. • Both sexual and asexual propagation methods make Apocynum cultivation a great opportunity for the vegetation restoration on saline soils Apocynum belongs to Apocynaceae family, is known as highly stress tolerant plant genus. Apocynum venetum L. and Apocynum pictum Schrenk, locally known as luobuma in China, are used as traditional medical plants and cash crops, and used for the phytoremediation of degraded saline lands. This review was aimed to critically analyzed the biological uses, salt tolerance mechanisms, and propagation methods of both Apocynum species to highlight the significance of the cultivation of Apocynum as a great opportunity for the vegetation restoration in saline soils in the arid region. In saline area, where arable crop production is nearly impossible due to high salt toxicity in soil, cultivation of Apocynum can reduce the levels of salt in soils and can also provide livelihood in the form of high-quality fibre. Critical literature analysis showed that overall salinity tolerance in Apocynum is associated with the regulation of redox regulation and ionic homeostasis, however their molecular regulation has not been identified yet. Findings such as removal of Na+ from soils and enhanced accumulation of flavonoids and antioxidants in leaves under saline environment, are useful in understanding the complex network of salt tolerance in Apocynum. Moreover, the practical adoption and application of different sexual and asexual propagation methods also play an important role in the successful cultivation of Apocynum in saline soils. To sum up, there are broad prospects for vigorously developing Apocynum industry by utilizing saline-alkali lands and carrying out research on cultivation technology and conservation strategy of Apocynum resources in arid lands. [ABSTRACT FROM AUTHOR]

Soil salinization threatens agricultural sustainability, especially for arid and semiarid regions. Planting euhalophytes with drip irrigation is proposed to be a feasible solution for the reclamation of saline soils. Thus, by planting an annual halophyte Suaeda salsa with drip irrigation, we assessed the potential of S. salsa to accumulate high amount of salt from soil and change in soil salinity levels in a three-year field study in arid northwestern China. The aboveground parts of S. salsa contained >20% ash salt on a dry weight basis and Na+ and Cl− were the main components. For each year, salt extraction by the aboveground part of S. salsa was ranged from 3749 to 3911 kg ha−1. Soil salinity dramatically decreased year by year by the cultivation of S. salsa , especially in the topsoil layer (0–40 cm). Our study suggested that consecutive cultivation of S. salsa with drip-irrigation is an efficient method to reclaim saline soil in arid and semiarid regions. [ABSTRACT FROM AUTHOR]

Under the sufficient nitrogen supply, it is of great significance to investigate the law of biomass allocation, root morphological traits, and the salt absorption capacity of euhalophytes to evaluate their biological desalination in saline soil. Although the curvilinear responses of biomass accumulation and root morphology in response to soil salinity have been recognized, these perceptions are still confined to the descriptions of inter-treatment population changes and lack details on biomass allocation in organs at an individual level. In this study, Suaeda salsa was grown in root boxes across a range of soil salt levels. The study showed that their growth and development were significantly affected by soil soluble salts. The law of biomass allocation was described as follows: increased soil soluble salts significantly increased the leaf mass ratio and decreased the stem mass ratio, and slightly increased the root mass ratio among treatments. For individuals at each treatment, leaf mass ratio > stem mass ratio > root mass ratio, except in the control treatment at the flower bud and fruit stages. Biomass responses of the control treatment indicated that salt was not rigorously required for Suaeda salsa in the presence of an adequate nitrogen supply, as verified by the correlation between biomass, nitrogen, and soil soluble salt. Salt could significantly inhibit the growth of Suaeda salsa (P<0.01), whereas nitrogen could significantly promote its growth (P<0.01). Root morphology in response to soil soluble salts showed that salt acquisition by the root was highest at a salt level of 0.70%, which corresponds to light saline soil. Consequently, we conclude that phytodesalination by Suaeda salsa was optimal in the light saline soil, followed by moderate saline soil., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Wang, Guo, Tian, Zhao, Zhang and Mai.)

Sustainable agricultural development in semiarid and arid regions is severely restricted by soil and water salinization. Cultivation of the representative halophyte Suaeda salsa , which can be irrigated with saline water and cultivated on saline soils, is considered to be a potential solution to the issues of freshwater scarcity, soil salinization, and fodder shortage. However, the salt removal capacity and differences in the forage nutritive value of S. salsa under different saline water treatments remain unknown. Using the methods of field trials and randomized blocks design, we quantified salt accumulation in the aboveground biomass, and the biochemical and nutritive value of field-cultivated S. salsa in arid northwestern China under irrigation with water of different salinities [i.e., freshwater or water containing10, 20, 30, or 40 g/L NaCl). The fresh and dry weights of S. salsa increased, then decreased, with increase in salinity. The salt content of the plant's aboveground biomass increased to a constant range and, thus, the salt extraction of S. salsa was relatively stable under different salinities of irrigation water. Under the experimental conditions, the crude protein content significantly increased to 9.45% dry weight (DW) and then decreased to 6.85% DW, with an increase in salinity ( p  < 0.05). The neutral detergent fiber (42.93%-50.00% DW) and acid detergent fiber (34.76%-39.70% DW) contents were suitable for forage. The contents of trace elements, such as copper and zinc, were significantly increased after irrigation with saline water ( p  < 0.05). The forage of S. salsa is of high nutritive value for livestock, and contains low concentrations of anti-nutrients. Therefore, S. salsa can be considered for cultivation in saline soils irrigated with saline water. In addition, it provides a viable additional source of fodder in arid regions, where the availability of freshwater and non-saline arable land is limited., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Wang, Zhao, Zhang, Liu, Zhang and Hu.)

Background: The halophyte Suaeda aralocaspica performs complete C4 photosynthesis within individual cells (SCC4), which is distinct from typical C4 plants, which require the collaboration of 2 types of photosynthetic cells. However, despite SCC4 plants having features that are valuable in engineering higher photosynthetic efficiencies in agriculturally important C3 species such as rice, there are no reported sequenced SCC4 plant genomes, limiting our understanding of the mechanisms involved in, and evolution of, SCC4 photosynthesis., Findings: Using Illumina and Pacific Biosciences sequencing platforms, we generated ∼202 Gb of clean genomic DNA sequences having a 433-fold coverage based on the 467 Mb estimated genome size of S. aralocaspica. The final genome assembly was 452 Mb, consisting of 4,033 scaffolds, with a scaffold N50 length of 1.83 Mb. We annotated 29,604 protein-coding genes using Evidence Modeler based on the gene information from ab initio predictions, homology levels with known genes, and RNA sequencing-based transcriptome evidence. We also annotated noncoding genes, including 1,651 long noncoding RNAs, 21 microRNAs, 382 transfer RNAs, 88 small nuclear RNAs, and 325 ribosomal RNAs. A complete (circular with no gaps) chloroplast genome of S. aralocaspica 146,654 bp in length was also assembled., Conclusions: We have presented the genome sequence of the SCC4 plant S. aralocaspica. Knowledge of the genome of S. aralocaspica should increase our understanding of the evolution of SCC4 photosynthesis and contribute to the engineering of C4 photosynthesis into economically important C3 crops., (© The Author(s) 2019. Published by Oxford University Press.)

Screening low-cost, high efficacy and environmentally safe surface active agents is critical for achieving successful surfactant-enhanced remediation (SER) of soil contaminated with hydrophobic organic compounds. This study reports the solubilization of organochlorine pesticides (DDT or gamma-HCH) in oil-in-water (Winsor I) microemulsions (microE) composed of non-ionic surfactant (Tween 80 or Triton X-100), plant oil (linseed oil or soybean oil), and the cosurfactant (1-pentanol). Results show that the cosurfactant to surfactant ratio (C/S ratio, w/w) is the major factor influencing the microemulsion formation, and C/S ratios of 1:3 and 1:6 are superior to 1:1 for microemulsion formation. 66.9-95.6% and 51.9-80.9% of DDT solubilization enhancements were achieved by microemulsions based respectively on Tween 80 or Triton X-100 as compared to their respective surfactant solution alone, indicating the higher solubilizing capacities of microemulsion systems. The solubilization of gamma-HCH also increased by 40.6-57.5% in microemulsion formed with Tween 80 and 43.0-65.8% in microemulsion formed with Triton X-100, compared with that in corresponding surfactant solutions only. Further studies revealed that both cosurfactant content and oil content could influence the solubilizing capacity of microemulsions system, and higher solubilizing capacity could be obtained when more cosurfactant or oil were emulsified in microemulsion system. Between the two, oil content is more influential than cosurfactant content. The present results affirm the effective role of microemulsions formed with Tween 80 and Triton X-100 in enhancing the solubilization of DDT and gamma-HCH which would facilitate remediation of soils contaminated with these compounds.

A thermophilic bacterial strain, Acinetobacter calcoaceticus BU03, with a biosurfactant-producing capability, was isolated from petroleum-contaminated soil with an improved procedure which employed the solubilization of polycyclic aromatic hydrocarbons (PAHs), i.e. naphthalene in agar plate, as a selection criterion. Crude biosurfactant was recovered from the culture of BU03 by extraction with n-hexane, and its properties were investigated. Biosurfactants from A. calcoaceticus BU03 constitute a thermo-stable mixture, composed of different agents with surface activities. At their critical micelle concentration (CMC) of 152.4 mg L(-1), the crude biosurfactants produced from A. calcoaceticus BU03 decreased the air-water surface tension to 38.4 mN m(-1). In thermophilic conditions, the emulsifying activity is 2.8 times that of Tween 80. The effects of the biosurfactants produced by A. calcoaceticus on the solubility and biodegradation of PAHs were investigated in batch systems. Biosurfactants produced by A. calcoaceticus BU03 at 25 times their CMC significantly increased the apparent aqueous solubility of phenanthrene (PHE), pyrene (PYR) and benzo(a)pyrene (B[a]P) to 54.3, 6.33 and 2.08 mg L(-1), respectively. In aqueous system, the biosurfactants at concentrations of 0.5 CMC and 1 CMC slightly enhanced the biodegradation of PHE by a consortium of PAH-degrading microrganisms. Results indicate that biosurfactants from A. calcoaceticus BU03 have potential to enhance the removal of PAHs from contaminated sites.

The bioavailability and biodegradation of polycyclic aromatic hydrocarbons (PAHs) can be increased through the addition of surfactants. Previous studies of this nature have been conducted under mesophilic conditions. Hence, the aim of the present study was to investigate the effects of synthetic surfactants and biosurfactants on solubilization and degradation of phenanthrene (PHE) in a series of batch solution experiments under thermophilic conditions. Tween 80, Triton X-100, and biosurfactants produced from Pseudomonas aeruginosa strain P-CG3 (P-CG3) and Pseudomonas aeruginosa ATCC 9027 (P. 9027) were used in this study. Surfactants effectively enhanced the solubility of PHE at 50 degrees C and the biosurfactant from P-CG3 was most effective with a 28-fold increase in apparent solubility of PHE at a concentration of 10 x critical micelle concentration (CMC) compared with the controls. However, addition of synthetic surfactants or biosurfactants inhibited the biodegradation of PHE in mineral salts medium by an isolate Bacillus sp. B-UM. Degradation of PHE diminished with increasing surfactant concentrations, and PHE degradation was completely inhibited for all the surfactants tested when the concentrations were greater than their respective CMC. The growth test suggested that Tween 80 and biosurfactants were degradable, but preferential utilization of these surfactants as substrates was not the mechanism for explaining the inhibition of PHE biodegradation. Because of the hydrophobic property of B-UM, degradation inhibition of PHE by surfactants was probably due to the reduction of direct contact between bacterial cells and PHE.