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Heavy precipitation events can exert greater impact than general precipitation on the economy, ecology, and people's livelihoods. Based on CN05.1 daily precipitation data and the NCEP/NCAR global daily reanalysis dataset, this study analyzes the characteristics of clustered heavy precipitation (CHP) events during summer in Northeast China (NEC) during 1961–2020, with consideration of associated atmospheric circulations and moisture transport. Results indicate that CHP events occurred mainly during midsummer, especially in July. Both the frequency and the intensity of CHP events decrease after the mid-1970s, increase after the early 1980s, and then diminish again after the 2000s. The CHP events occur in association with an anomalous lower-tropospheric cyclone centered over NEC, northward and westward shifts of the western North Pacific subtropical high in the middle troposphere, and northward shift of an intensified westerly jet in the upper troposphere, in conjunction with strengthened local convective motion. Additionally, the net moisture budget begins to increase 2 days before the occurrence of CHP and peaks 6 h earlier than the CHP. Further results indicate that net moisture influx across the southern boundary of NEC made a dominant contribution to the net moisture budget. The results of this study have importance regarding the prediction of CHP events over NEC. [ABSTRACT FROM AUTHOR]

This study investigated the contribution of Arctic sea ice concentration (SIC) on decadal variations of the dominant mode of summer precipitation over eastern China during 1981–2020. The spatial pattern of leading empirical orthogonal function mode has changed from a dipole pattern with negative anomalies over Jianghuai Valley and positive anomalies over southern China during 1981–2001 to the Yangtze River Valley (YRV) pattern during 2002–2020. Spring SIC over Kara Sea was significantly related to the dipole pattern, through influencing Eurasian snow depth. The associated anomalous temperature gradient and atmospheric circulation affected the meridional displacement of the East Asian subtropical jet, which favored the dipole pattern of summer precipitation. For the YRV pattern, spring SIC over Greenland Sea has an impact on the sea surface temperature anomalies in the western Pacific by triggering a wave train that influenced the precipitation through the establishment of the Pacific–Japan pattern. The results of this study may provide reference value for the prediction of summer precipitation over eastern China. Plain Language Summary: As Eastern China has a high level of national economic development and experiences significant variations in summer precipitation, it is crucial to comprehend the patterns and trends of rainfall. However, it is challenging to accurately predict the decadal variations of precipitation due to the intricate physical processes involved. Therefore, we consider exploring the causes of the decadal variations from the perspective of Arctic SIC. The study demonstrates the dominant mode of eastern China summer precipitation (ECSP) undergone a decadal variation at the early 2000s, and spring SIC over Kara Sea and Greenland Sea play great impacts on it. These results may have potential implications for ECSP forecasting. Key Points: Dominant mode of the summer precipitation over eastern China (ECSP) experienced a decadal variation at the early 2000sSpring sea ice concentration (SIC) over Kara Sea contributed to the dipole pattern of ECSP by influencing the Eurasian snow depth during 1981–2001Spring SIC over Greenland Sea impacted the Yangtze River Valley pattern through the western Pacific sea surface temperature during 2002–2020 [ABSTRACT FROM AUTHOR]

Using the standardized precipitation evapotranspiration index, this article demonstrates that the intensity of interannual variability (IIV) of May drought in Northeast China has enhanced remarkably after entering into the 21st century. Relative to 1980–1999, the percentage increase of IIV reaches 70% during 2000–2016. Such an enhancement is well supported by the intensification of IIVs in the East Asian polar front jet stream (EAPJ), East Asian subtropical jet stream (EASJ), and lower‐level anticyclonic circulation anomaly over Northeast China. Remarkable impact from the Barents Sea ice in April is also highlighted. With respect to the former period, a substantial increase occurs as well in the IIV of April Barents Sea ice during 2000–2016. Due to larger IIV in the latter period, the decline of April Barents Sea ice can exert evident effects on heat fluxes, consequently resulting in a significant increase of surface air temperature (SAT) in situ in May. The increased SAT further induces a wave train propagating southeastward to the East Asian region from the Barents Sea, which leads to a strengthened EAPJ and a weakened EASJ in the upper level, concomitant with an anomalous anticyclonic circulation covering Northeast China in the lower level. These atmospheric circulation anomalies link to the drought variability over Northeast China. Thus, the increase in the IIV of April Barents Sea ice favors the enhanced IIV of May drought in Northeast China. Plain Language Summary: Northeast China serves as an important granary in China. In recent decades, frequent occurrences of drought exert adverse effects on agriculture production and human lives in this region. Thus, better understanding of drought variability in Northeast China is an urgent need. In this study, we revealed an increase in the intensity of interannual variability (IIV) of May drought in Northeast China after 2000, which is well supported by the increased IIVs of the East Asian polar front jet stream, East Asian subtropical jet stream, and lower‐level anticyclonic circulation anomaly over Northeast China. Further examination suggested that the April Barents Sea ice with larger IIV after 2000 plays a pronounced role, by means of modulating the thermal conditions and associated wave train. The results are encouraging to improve the understanding about the interannual variability of drought in Northeast China, and act as a scientific basis for food security and human lives. Key Points: The intensity of interannual variability of May drought in Northeast China has enhanced after 2000Such an enhancement is supported by the intensified interannual variability of associated atmospheric circulationsThe Barents Sea ice variability in April plays a role through effects on the thermal condition [ABSTRACT FROM AUTHOR]

Compared with individual extreme events, compound events have more severe impacts on humans and the natural environment. This study explores the change in severity of compound extreme high temperature and drought/rain events (CHTDE/CHTRE) and associated influencing factors. The CHTDE and CHTRE intensified in most areas of China in summer (June–July August) during 1961–2014. Under global warming, the increased water-holding capacity of the atmosphere and the decreased relative humidity led to an increase in the severity of CHTDE. The severity of CHTRE is increased because of enhanced transient water vapor convergence and convective motion. Anthropogenic climate change, especially greenhouse gas forcing, which contributes 90% to the linear change in the severity of CHTDE and CHTRE, is identified as the dominant factor affecting the severity of CHTDE in China. In addition, the historical natural forcing (hist-NAT) may be related to the interannual-to-decadal variability in the severity of CHTDE/CHTRE. [ABSTRACT FROM AUTHOR]

Based on the standardized precipitation evaporation index and reanalysis data, this article reveals that the relationship between the North Pacific Oscillation (NPO) and the drought over southern China in summer shifts from an insignificant correlation to a significant negative correlation after 2000. During the significant period (2001–2018), the positive NPO phase corresponds to an anomalous anticyclonic circulation dominating the mid‐low latitude North Pacific, which suppresses the moisture transport into southern China. Meanwhile, the easterly anomalies south of the anomalous anticyclonic circulation prevailing in the equatorial Pacific are coupled with a cooling of sea surface temperature in the central tropical Pacific, which enhances the Walker circulation and further induces an anomalous meridional circulation with the descending anomalies over southern China. Such moisture and dynamical conditions favor the occurrence of drought in southern China. During the former period (1983–2000), however, the NPO‐related atmospheric circulations over the North Pacific shift northward. In this case, the NPO shows insignificant relations with the moisture and dynamical conditions over southern China, thereby diluting the linkage of the NPO to the drought in southern China. The interdecadal strengthening in the relationship between the NPO and above atmospheric conditions is attributed to the westward (southward) extension of the NPO northern (southern) center. The larger interannual variability of spring sea ice in the Bering Sea and the southward movement of summer storm track over the North Pacific are hypothesized to account for the expansion of the NPO structure. Plain Language Summary: Southern China is an economically developed region with a large population. In recent decades, droughts frequently occurred in this region and severely affected agriculture production, forest‐fire prevention, and human lives. Therefore, it is very necessary to understand the physical mechanisms underlying the variability of droughts in southern China. In this study, we addressed the relationship of summer drought in southern China with the North Pacific Oscillation (NPO), which is characterized by the north–south seesaw pattern in sea level pressure over the North Pacific. We revealed that their relationship exhibits an interdecadal change around 2000, from an insignificant correlation to a significant negative correlation. Such an interdecadal strengthening is due to the expansion of the NPO structure, which may result from the changes of the spring sea ice in the Bering Sea and the summer storm track over the North Pacific. These findings are expected to deepen our understanding for the variation of drought in southern China and are also important for disaster prevention and mitigation. Key Points: Relationship between the summer drought in southern China and the North Pacific Oscillation (NPO) has strengthened after 2000Such a strengthening is attributed to the westward (southward) extension of the NPO northern (southern) centerThe expansion of the NPO structure is related to changes of spring sea ice in the Bering Sea and summer storm track over the North Pacific [ABSTRACT FROM AUTHOR]

Analyses of the standardized precipitation evaporation index (SPEI), using the season-reliant empirical orthogonal function (S-EOF) method, indicate that the second leading mode of drought over Northeast China features an in-phase variation from spring to summer. Such an in-phase change is closely connected to the persistence of geopotential height anomalies around Lake Baikal. The positive height anomalies around Lake Baikal, with an equivalent barotropic structure in the troposphere, can decrease water vapor transport into Northeast China and induce anomalous descending motion over Northeast China during both seasons, favoring precipitation deficit and high temperature in situ and hence resulting in the synchronous variations of spring and summer droughts. Further investigation reveals that the spring North Atlantic Oscillation (NAO) plays a notable role in the in-phase change of spring–summer droughts over Northeast China. The positive phase of spring NAO could induce spring drought over Northeast China directly through its influence on the above atmospheric circulations via a zonal wave train emanating from the North Atlantic. Meanwhile, it can also increase the soil moisture in central Siberia by enhancing the local snow depth. The wetter soil moisture in the following summer, in turn, increases the meridional temperature gradient between the middle and high latitudes and then forces westerly anomalies around 60°N, consequently yielding positive height anomalies around Lake Baikal that favor the occurrence of summer drought over Northeast China. Therefore, the spring NAO is hypothesized to contribute to the in-phase variations of spring–summer droughts over Northeast China through the combined roles of zonal wave train and central Siberian soil moisture. Significance Statement: Northeast China suffers from frequent droughts severely in recent decades. Thus, it is urgent to understand the physical mechanisms of drought in Northeast China. Using the season-reliant empirical orthogonal function (S-EOF) analysis, this study indicates that the second mode of S-EOF shows an in-phase change of drought from spring to summer over Northeast China, which is associated with the persistence of geopotential height anomalies around Lake Baikal. Our study further reveals that the spring NAO plays a pronounced role in the in-phase change of spring–summer droughts over Northeast China, through the combined roles of zonal wave train and the soil moisture in the central Siberian plateau. These findings are encouraging for better understanding of drought in Northeast China and are also important for disaster prevention and mitigation. [ABSTRACT FROM AUTHOR]

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This study investigates the first two leading modes of the interannual variability of frequency of snowfall events (FSE) over China in the winter during 1986–2018. The positive phase of the first leading mode (EOF1) is mainly characterized by positive FSE anomalies in northeastern–northwestern China and negative FSE anomalies in the three-river-source region. In contrast, the positive phase of the second leading mode (EOF2) is mainly characterized by positive FSE anomalies in central-eastern China (CEC). EOF1 is affected by the synoptic-scale wave activity over the midlatitudes of the East Asian continent, where active synoptic-scale wave activity over the midlatitudes may cause increased FSE over northeastern–northwestern China, and vice versa. In a winter of a negative phase of the North Atlantic Oscillation, an anomalous deep cold low may occur over Siberia, which may induce increased meridional air temperature gradient, increased atmospheric baroclinicity, and hence increased FSE over the midlatitudes of the East Asian continent. The EOF2 is affected by the interaction between anomalous northerly cold advection and anomalous southerly water vapor transport over CEC. The positive phase of EOF2 is associated with negative sea ice anomalies in the Barents Sea–Kara Sea region and negative sea surface temperature anomalies in the central-eastern tropical Pacific. Reduced sea ice in the Barents Sea–Kara Sea during January–February may cause increased northerly cold advection over CEC, while a La Niña–like condition during January may induce southerly water vapor transport anomalies over CEC. [ABSTRACT FROM AUTHOR]

Based on the long-term reanalysis datasets and the multivariate copula method, this study reveals that the frequency of summer hot drought events (SHDEs) over northeastern China (NEC) shows interdecadal variations during 1925–2010. It is revealed that the summer sea surface temperature (SST) over the North Atlantic has a significant positive correlation with the frequency of SHDEs over NEC on the decadal time scale, indicating a potential influence of the Atlantic multidecadal oscillation (AMO). Further analyses indicate that during the positive phases of the AMO, the warming SST over the North Atlantic can trigger a stationary Rossby wave originating from the North Atlantic, which splits into two wave trains propagating along two different routes. One is a zonally orientated wave train that resembles the Silk Road pattern, whereas the other is an arching wave train that resembles the polar–Eurasian pattern. A negative (positive) phase of the Silk Road pattern (polar–Eurasian pattern) may result in the weakened westerly wind along the jet stream, the downward vertical motion, and the anomalous positive geopotential center over NEC, providing favorable conditions for precipitation deficiency and high temperature and resulting in increased SHDEs. Thus, the Silk Road pattern and the polar–Eurasian pattern serve as linkages between the AMO and SHDEs over northeastern China in summer on the interdecadal time scale. Model simulations from CAM4 perturbed with warmer SST in the North Atlantic show precipitation deficiency and high temperature conditions over northeastern China in summer, supporting the potential impacts of the North Atlantic SST on SHDEs over northeastern China. The results suggest that the phase of the AMO should be taken into account in the decadal prediction of SHDEs over northeastern China in summer. [ABSTRACT FROM AUTHOR]

Anthropogenic conversion of natural to agricultural land reduces aboveground biodiversity. Yet, the overall consequences of land‐use changes on belowground biodiversity at large scales remain insufficiently explored. Furthermore, the effects of conversion on different organism groups are usually determined at the taxonomic level, while an integrated investigation that includes functional and phylogenetic levels is rare and absent for belowground organisms. Here, we studied the Earth's most abundant metazoa—nematodes—to examine the effects of conversion from natural to agricultural habitats on soil biodiversity across a large spatial scale. To this aim, we investigated the diversity and composition of nematode communities at the taxonomic, functional, and phylogenetic level in 16 assemblage pairs (32 sites in total with 16 in each habitat type) in mainland China. While the overall alpha and beta diversity did not differ between natural and agricultural systems, all three alpha diversity facets decreased with latitude in natural habitats. Both alpha and beta diversity levels were driven by climatic differences in natural habitats, while none of the diversity levels changed in agricultural systems. This indicates that land conversion affects soil biodiversity in a geographically dependent manner and that agriculture could erase climatic constraints on soil biodiversity at such a scale. Additionally, the functional composition of nematode communities was more dissimilar in agricultural than in natural habitats, while the phylogenetic composition was more similar, indicating that changes among different biodiversity facets are asynchronous. Our study deepens the understanding of land‐use effects on soil nematode diversity across large spatial scales. Moreover, the detected asynchrony of taxonomic, functional, and phylogenetic diversity highlights the necessity to monitor multiple facets of soil biodiversity in ecological studies such as those investigating environmental changes. [ABSTRACT FROM AUTHOR]

This study aims to characterize future changes in precipitation extremes over China based on regional climate models (RCMs) participating in the Coordinated Regional Climate Downscaling Experiment (CORDEX)-East Asia project. The results of five RCMs involved in CORDEX-East Asia project that driven by HadGEM2-AO are compared with the simulation of CMA-RegCM driven by BCC-CSM1.1. Eleven precipitation extreme indices that developed by the Expert Team on Climate Change Detection and Indices are employed to evaluate precipitation extreme changes over China. Generally, RCMs can reproduce their spatiotemporal characteristics over China in comparison with observations. For future climate projections, RCMs indicate that both the occurrence and intensity of precipitation extremes in most regions of China will increase when the global temperature increases by 1.5/2.0 °C. The yearly maximum five-day precipitation (RX5D) averaged over China is reported to increase by 4.4% via the CMA-RegCM under the 1.5 °C warming in comparison with the baseline period (1986–2005); however, a relatively large increase of 11.1% is reported by the multi-model ensemble median (MME) when using the other five models. Furthermore, the reoccurring risks of precipitation extremes over most regions of China will further increase due to the additional 0.5 °C warming. For example, RX5D will further increase by approximately 8.9% over NWC, 3.8% over NC, 2.3% over SC, and approximately 1.0% over China. Extremes, such as the historical 20-year return period event of yearly maximum one-day precipitation (RX1D) and RX5D, will become more frequent, with occurrences happening once every 8.8 years (RX1D) and 11.5 years (RX5D) under the 1.5 °C warming target, and there will be two fewer years due to the additional 0.5 °C warming. In addition, the intensity of these events will increase by approximately 9.2% (8.5%) under the 1.5 °C warming target and 12.6% (11.0%) under the 2.0 °C warming target for RX1D (RX5D). [ABSTRACT FROM AUTHOR]

• A probability-based index is calculated to represent concurrent heatwaves and droughts. • Physical mechanisms of concurrent heatwaves and droughts are recognized. • Independent predictors are used to construct a physical-empirical prediction model. Concurrent heatwaves and droughts that occur over northeastern China (NEC) bring severe threats to human lives and crop production. Despite the great efforts taken in previous studies, realistic prediction of these concurrent extreme events remains a challenge. In the present study, a probability-based index that simultaneously considers precipitation deficiency and high temperature is calculated to represent concurrent heatwaves and droughts in July–August over NEC. Based on this index, the characteristics of concurrent heatwaves and droughts over NEC in July–August are investigated using the year-to-year increment approach. The results indicate that the occurrence of concurrent heatwaves and droughts over NEC is closely related to the Polar-Eurasian teleconnection pattern and the Pacific-Japan teleconnection pattern. Further analyses indicate that the sea ice content in the Barents Sea in March ( SICBS ), the La Niña-like sea surface temperature (SST) in February ( SST-PC1 ), and the northwestern Siberia soil moisture in April ( SM ) are coincidently linked to the two teleconnection patterns mentioned above. Based on their corresponding physical mechanisms, these three independent predictors are chosen to construct a physical-empirical prediction model for the prediction of concurrent heatwaves and droughts over NEC. Results suggest that this physical-empirical prediction model performs well with a high correlation coefficient and a low root mean squared error between the observed and predicted concurrent heatwaves and droughts over NEC during the period of 1979–2018. Moreover, the cross-validation test and independent hindcasts both suggest that the physical-empirical model proposed in the present study with the three independent predictors has good prediction skills. [ABSTRACT FROM AUTHOR]

Previous studies have documented that the summer precipitation over South China (SC) has experienced a prominent inter-decadal increase in 1992/1993, and the possible mechanism has been well revealed. The aim of this study is to investigate the changes in extreme precipitation and clustered extreme precipitation events in recent decades using station observations and the National Centers for Environmental Prediction/National Center for Atmospheric Research (NCEP/NCAR) reanalysis data. The results indicate that extreme precipitation also experienced a significant inter-decadal increase around 1992/1993. Significant changes can also be found in the associated atmospheric circulations, such as the western North Pacific subtropical high (WNPSH) and the westerly jet stream over East Asia. In addition, the water vapour transport (WVT) related to extreme precipitation differed from mean conditions. For extreme precipitation events, the WVT from the Northwest Pacific and Indian Oceans was much stronger when compared with mean precipitation. When extreme precipitation events were clustered, the increased WVT mainly originated from the South China Sea and Northwest Pacific Ocean. Further analysis indicates that the WVT increased from the Indian Ocean but decreased from the Northwest Pacific after 1992/1993; this inding explains the significant increase in the clustered extreme precipitation events over SC after 1992/1993. In addition, the atmospheric stratification has become more unstable since 1992/1993. [ABSTRACT FROM AUTHOR]

This study investigates the influence of external forcings on the various summer hot drought events (SHDEs) over northeastern China (NEC). SHDEs are represented by the probability‐based index (PI), which considers precipitation and temperature anomalies. The results show that SHDEs over NEC increased from 1961 to 2005, and the experiments for historical forcing (ALL), increased greenhouse gases emission forcing (GHG), and anthropogenic forcing (ANT) can largely reproduce the spatial and temporal features of the trends of SHDEs over NEC. Based on the optimal fingerprinting method, the impact of increased anthropogenic activities can be detected at the 90% confidence level. In addition, the attributable changes of PI in response to GHG and ANT forcings resemble the observation, implying that the increasing trends of SHDEs over NEC are primarily attributed to the increased anthropogenic activity. Furthermore, the occurrence probability of SHDEs over NEC will be further increased under different Representative Concentration Pathways in the future. Additional strict control regulations on GHG emissions are thus suggested to mitigate its impact on regional climate changes. Key Points: Summer hot drought events over northeastern China are observed to increase in recent decadesEffects of anthropogenic activity emerge as an important factor to increase the summer hot drought events over northeastern ChinaThe frequency and the intensity of summer hot drought events over northeastern China will be further strengthened in the future [ABSTRACT FROM AUTHOR]

Hot drought events often have great impacts on society, the ecosystem, and agriculture. Northeastern China (NEC) is the ganary of China, thus it is quite important to investigate the characteristics of summer hot drought event (SHDE) over NEC and find the possible mechanisms. Based on the observation and the reanalysis datasets, we found that the decline of Barents Sea ice (SICBS) in March is closely related to the occurrence of summer SHDE over NEC during 1997-2016. The decline of SICBS can lead to decrease of snow depth over the western Eurasia (SDWEA) in April. On the one hand, the decline of SDWEA in April can regulate the atmospheric circulation during May-June that lead to dry soil in Yangtze River valley and northern China regions, which is further linked to SHDE over NEC. On the other hand, both the decline of SICBS in March and the decrease of SDWEA in April favor the positive Polar/Eurasia teleconnection pattern and dry soil over NEC in JA, which provides favorable atmospheric circulation patterns for SHDE over NEC. All of these results can be verified by the simulations from the Community Earth System Model and the numerical experiments that based on the version 4 of Community Atmosphere Model. Consequently, the Barents Sea ice in March might be a potential predictor for the SHDE over NEC. [ABSTRACT FROM AUTHOR]

• Fowl adenovirus (FAdV) -4 strain HN/151025 was highly virulent in 60-day-old chickens, causing 60 % mortality and typical Clinical signs and gross lesions. • FAdV-4 infection induced significant upregulation of genes encoding most toll-like receptors, some cytokines, most avian β-defensins, and other immunity-related molecules investigated in specific chicken tissues. • There was a significant positive correlation between FAdV-4 genome load and the mRNA expression levels of most of these markers in specific infected tissues. Fowl adenovirus (FAdV), as the causative agent of hepatitis-hydropericardium syndrome (HHS), poses a significant threat to the poultry industry in China in recent years. In this study, we investigated the immunopathogenesis of a FAdV-4 strain HN/151025 in 60-day-old chickens. The virus was highly virulent in chickens, with a broader tissue tropism in chickens, causing 60 % mortality. Postmortem findings of dead chickens showed mild HHS and liver degeneration and necrosis. Importantly, FAdV-4 infection induced significant upregulation of genes encoding most toll-like receptors, some cytokines (interleukin-1β, 2, 6, 8, and 18, and interferon-γ), most of avian β-defensins, myeloid differentiation primary response protein 88, p38 mitogen-activated protein kinases, and inducible nitric oxide synthase, in tissues of infected chicken, especially in spleen and bursa of Fabricius. There was also a significant positive correlation between FAdV-4 genome load and the mRNA expression levels of most of these factors in specific infected tissues. The results indicated the potential role of these proteins in host immune response against FAdV-4 infection. However, overexpression of these proteins might contribute to tissue damage of FAdV-4 infected chickens, and eventually lead to chicken death. [ABSTRACT FROM AUTHOR]

• Minimum data set includes four factors, which reflect the integrated soil function. • Significant differences in soil quality between different productivity. • The significant positive correlation between SQI and wheat yield. • Available N, SOM and microbial biomass N to total N ratio were limiting factors. The double-cropping of winter wheat and summer maize is a major grain production system in China which occupies more than half the double-cropping systems of the country's dryland area. This cropping system has experienced a decreased crop yield and soil quality and the limiting factors are poorly known. The goal of this study was to conduct a systematic evaluation of wheat yield and soil quality from 132 fields along a regional scale in China. The specific objectives were (i) to establish a minimum data set (MDS) in wheat phase under the wheat-maize cropping system (ii) to evaluate soil quality of the wheat field and determine the factors limiting wheat productivity. The wheat-maize cropping system was partitioned into three productivity levels (high, medium and low) according to the wheat yield. Twenty-six soil indicators, including soil microbiological, chemical and physical factors were measured and analyzed. Using Pearson correlation analysis we identified eight key soil indicators that determine wheat yield. We then used principal component analysis to determine an MDS, which included soil organic matter, alkali-hydrolyzable nitrogen, the ratio of microbial biomass nitrogen to total nitrogen, and available zinc. One-way analysis of variance based on the individual contribution of each MDS indicators under three productivity, revealed available nitrogen, soil organic matter and the ratio of microbial biomass nitrogen to total nitrogen was the most important indicators on limiting wheat yield. A soil quality index (SQI) based on scoring and weighting of MDS indicators was integrated as a tool for assessing farmland soil quality. Based on the MDS, high (HP), medium (MP) and low (LP) productivity received mean SQI of 0.55, 0.48 and 0.39, respectively. The significant positive correlation between SQI and wheat yield suggests that this is a good representative of the MDS for the wheat-maize cropping system in China. We conclude that our SQI may be an effective and practical tool to guide a strategic, regional goal with respect to sustainable high yields. [ABSTRACT FROM AUTHOR]

Cover crop can reduce the intensity of land use, and improve soil fertility and productivity in multiple-cropping systems. However, only a few studies have comprehensively evaluated soil health after cover crops in terms of management goal and soil multi-functionality. In this study, different minimum data set (MDS) methods were used to establish a soil health index (SQI) model to evaluate soil health of the winter smooth vetch-summer maize cropping system in southwest China. We analyzed thirty-five soil parameters (representing soil physical, chemical and biological properties) connected with the soil functions as potential soil health indicators in the phase of smooth vetch and maize under six management treatments (CK (control), N (N fertilizer), P (P fertilizer), NP (N and P fertilizer), NPW (N and P fertilizer + irrigation), CF (fallow)). Those managements were set in the smooth vetch phase (as a cover crop). The MDS using correlation analysis (cMDS), principal component analysis (pMDS) and random forest analysis (rMDS) from the total data set (TDS) were selected and then used for SQIs calculation, respectively. Cover crop by different management of irrigation and fertilization affected each soil property in different ways. All three SQIs were significantly correlated with SQI-TDS, validating the SQI models developed by three MDS methods (P < 0.05). Further, the SQI based on rMDS was the most accurate and sensitive, suggesting the RFA-based SQI reflects soil functions more adequately than the CA and PCA-based SQI. Cover crop by the management of fertilization or/and irrigation will not only improve soil health, but also enhance maize yield compared with fallow treatment, especially for NPW treatment. Fertilization treatments (N, P, NP and NPW) had higher soil health index, which was related to the better performance of soil in sustaining biological activity, physical stability and supporting function. In summary, the SQI model developed by the RFA method can provide a practical and robust tool for assessing soil health based on the management goal. • Cover crops can improve soil health index and maize yield. • Cover crops with balanced irrigation and fertilizer have better soil health. • Increasing soil health index significantly enhances maize yield. • Soil health index developed by random forest analysis had the most accurate ability. [ABSTRACT FROM AUTHOR]

We investigated the genomic characteristics of 110 LX4 genotype strains of infectious bronchitis viruses (IBVs) isolated between 1995 and 2005 in China. The genome of these IBVs varies in size from 27596 bp to 27790 bp. Most IBV strains have the typical genomic organization of other gamacoronaviruses, however, two strains lacked 3a and 5b genes as a result of a nucleotide change within the start codon in the 3a or 5b genes. Analysis of our 110 viruses revealed that recombination events may be responsible for the emergence of the LX4 genotype with different topologies. Most of these viruses disappeared (before mid-2005) because they were not “fit” to adaptation in chickens. Finally, those of the “fit” viruses (after mid-2005) continued to evolve and have become widespread and predominant in commercial poultry. In addition, few of these viruses experienced recombination with those of the vaccine strains at the 3′ end of the genome. [ABSTRACT FROM AUTHOR]

Avian infectious bronchitis coronavirus (IBV) is a major poultry pathogen. A characteristic feature of IBV is the occurrence of many different strains belonging to different serotypes, which renders complete control of the disease by vaccination a challenging task due to the poor cross-protection between different serotypes. In this study, based on the results of S1 sequence analysis and virus cross-neutralization tests, IBV strain ck/CH/LGX/111119 was found to be genetically and antigenically different from other known IBV types, representing not only a novel genotype, but also a novel serotype (designated as GI-28). Viruses belonging to this novel serotype have been isolated from several regions in China in recent years, suggesting endemic circulation of the serotype in various geographic locations in China. Further studies by complete genomic analysis showed that strain ck/CH/LGX/111119 may have originated from recombination events involving LX4 genotype IBVs and an as-yet-unidentified IBV donating a S1 gene, or from the result of accumulation of mutations and selections, especially in the S1 gene, from a LX4 genotype virus. ck/CH/LGX/111119 is a nephropathogenic strain, although it had broader tissue tropism (respiratory, digestive, urinary, and reproductive tracts) among chickens challenged at one day old. Infection of the oviducts with ck/CH/LGX/111119 found in this study may have severe implications because the virus will likely induce the occurrence of false layers. [ABSTRACT FROM AUTHOR]

In this study, 418 IBVs were isolated in samples from 1717 chicken flocks. Twenty-nine of the isolates were classified as the Massachusetts genotype. These 29 isolates, as well as two previously isolated Massachusetts genotype IBV strains, were studied further. Of the 31 strains, 24 were H120-like and two were M41-like isolates as determined by complete genomic sequence analysis, indicating that most of the IBV isolates were likely the reisolated vaccine virus. The remaining five IBV isolates, ck/CH/LHB/111172, ck/CH/LSD/111219, ck/CH/LHB/130598, ck/CH/LDL/110931, and ck/CH/LHB/130573, were shown to have originated from natural recombination events between an H120-like vaccine strain and other types of viruses. The virus cross-neutralization test found that the antigenicity of ck/CH/LHB/111172, ck/CH/LSD/111219, and ck/CH/LHB/130598 was similar to that of H120. Vaccination with the H120 vaccine offered complete protection against challenge with these isolates. However, isolates ck/CH/LDL/110931 and ck/CH/LHB/130573 were serotypically different from their parental viruses and from other serotypes in this study. Furthermore, vaccination with the H120 vaccine did not provide protection against challenge with these two isolates. The results of this study demonstrated that recombination is the mechanism that is responsible for the emergence of new serotype strains, and it has the ability to alter virus serotypes. Therefore, IBV surveillance of chicken flocks vaccinated with IBV live vaccines, as well as the consideration of new strategies to effectively control IBV infection using inactivated or/and genetically engineered vaccines, is of great importance. [ABSTRACT FROM AUTHOR]

Newcastle disease (ND) is one of the most devastating diseases to the poultry industry. The causative agents of ND are virulent strains of Newcastle disease virus (NDV), which are members of the genus Avulavirus within the family Paramyxoviridae . Waterfowl, such as ducks and geese, are generally considered potential reservoirs of NDV and may show few or no clinical signs when infected with viruses that are obviously virulent in chickens. However, ND outbreaks in domestic waterfowl have been frequently reported in many countries in the past decade. In this study, 18 NDV strains isolated from domestic ducks in southern and eastern China, between 2005 and 2013, were genetically and phylogenetically characterized. The complete genomes of these strains were sequenced, and they exhibited genome sizes of 15,186 nucleotides (nt), 15,192 nt, and 15,198 nt, which follow the “rule of six” that is required for the replication of NDV strains. Based on the cleavage site of the F protein and pathogenicity tests in chickens, 17 of our NDV isolates were categorized as lentogenic viruses, and one was characterized as a velogenic virus. Phylogenetic analysis based on the partial sequences of the F gene and the complete genome sequences showed that there are at least four genotypes of NDV circulating in domestic ducks; GD1, AH224, and AH209 belong to genotypes VIId, Ib, and II of class II NDVs, respectively, and the remaining 15 isolates belong to genotype 1b of class I NDVs. Cross-reactive hemagglutination inhibition tests demonstrated that the antigenic relatedness between NDV strains may be associated with their genotypes, rather than their hosts. These results suggest that though those NDV isolates were from duck, they still don’t form a phylogenetic group because they came from the same species; however, they may play an important role in promoting the evolution of NDVs. [ABSTRACT FROM AUTHOR]

• Adding organic materials to chemical fertilizer enhances crop yield and soil quality. • Organic materials with part chemical fertilizer (ORC) is the best regimes. • Crop yield-soil quality balance respond variously to climate and soil conditions. • Biochar, organic fertilizer or ORC can promote sustainable agricultural development. The contradiction between rapid soil degradation and increased food demand is becoming increasingly prominent. Reasonable recycling of agricultural waste can affect soil productivity and environmental health, thus playing a crucial role in the sustainability of agricultural production. Through a meta-analysis of 160 studies in the region of upland double cropping in China, we evaluate crop yield and soil quality responses to organic amendments. Results indicated that soil quality index (17.6%–26.3%) and crop yield (6.0%–9.0%) were significantly increased by adding organic amendments to chemical fertilizer. Combination of organic materials with total chemical fertilizer (OTC) and with part chemical fertilizer (ORC) significantly increased the yield by 8.3% and 8.7% and soil quality by19.5% and 18.4%, respectively. However, application of organic materials alone (O) decreased yields (by −0.6%), but significantly increased soil quality (by 49.1%). On average, organic amendments resulted in higher crop yield and soil quality index, despite variability introduced by tillage regimes and conditions of soil and climate. Relatively larger positive effect in crop yield and soil quality occurred with mean annual precipitation >1000 and <600 mm, respectively. Additional analyses found that biochar, organic fertilizer or ORC can promote sustainable agricultural development via improving crop yields, soil quality, and reducing nitrogen losses. Our results provide the first systematic review of effect of the organic amendments on the balance between soil quality and crop yield. The findings suggest that impacts of adding organic amendments to chemical fertilizer may be used as the foundation for policies. However, the combined use of organic amendments and other farmland management practices still present an area that needs further research in order to promote sustainable development of agriculture. [ABSTRACT FROM AUTHOR]

• Organic input can improve soil quality by the interaction of soil properties. • Use animal-derived organic fertilizer had better soil quality than plant-derived. • AP, AN, GP and AK were selected as a minimum data set for evaluating soil quality. • Information from soil indicators is integrated into a standardization framework. • Appropriate methods of scoring and weighting are determined in the framework. Organic fertilizer applications can increase soil fertility and productivity and reduce chemical fertilizer use. However, few experimental studies have focused on effects of organic fertilizers on soil quality in a field ecosystem. The overarching goal of this study was to develop a soil quality index (SQI) for fertilization management in red soil farmland in China. The specific objectives were to determine 1) appropriate soil quality indicators, 2) a suitable weight assignment method (PCA, principal component analysis or MRA, multiple regression analysis) and 3) the optimal scoring function (standard or linear or non-linear). We analyzed 40 soil physical, chemical, biochemical and biological properties under nine fertilization treatments (CK (no fertilizer), CF (chemical fertilizer), RF (60% chemical fertilizer), CFS (chemical fertilizer + straw), RFS (60% chemical fertilizer + straw), CFB (chemical fertilizer + biochar), RFB (60% chemical fertilizer + biochar), RFP (60% chemical fertilizer + pig manure), RFV (60% chemical fertilizer + vermicompost)) as potential soil quality indicators. Principal component analysis and correlation analysis were applied to determine the indicators responsive to management and for the confirmation of the six SQIs. Available phosphorous, nitrogen, potassium and gram-positive bacteria were chosen as the minimum data set from the total of 40 soil indictors. Management of organic and inorganic fertilizers affected each soil property in different ways, and the index based on the minimum data set, calculated using standard scoring function and weight assignment method of multiple regression analysis, was most accurate and sensitive. Application of a pig manure or vermicompost significantly increased SQI values relative to other treatments, followed by straw or biochar treatments which were higher than a single application of chemical fertilizer. These results indicate that the addition of organic fertilizers will not only improve soil quality, but also enhance rapeseed and sweet potato yield compared to chemical fertilizers. Additionally, the SQI method can provide a practical and quantitative tool for the evaluation of soil quality. [ABSTRACT FROM AUTHOR]

In the present study, a thorough comparison of the infectious bronchitis virus (IBV) TC07–2/GVI-1 linage was conducted by comparing the S1 gene sequences of GVI-1 viruses with those of viruses representing the established genotypes and lineages. IBV GVI-1 strains were found to be closely genetically related to each other, irrespective of where the viruses were isolated, and differed from other known IBV genotypes and lineages; thus, it was confirmed that GVI represents a novel genotype. However, the GVI-1 viruses exhibited variable antigenicity when compared to each other. Further analysis found that strains CO8089L and CO8091L, which were isolated in Colombia in 2003, were closely related to GVI-1 viruses, suggesting that GVI-1 viruses likely originated from Colombia and are prevalent in at least five countries (Colombia, China, the Republic of Korea, Japan, and Vietnam). Analysis of the complete GVI-1 virus genomes suggested that the GVI-1 strains in China may be independently derived from recombination events that occurred between GI-19 strains and CO8089L/CO8091L-like viruses following the introduction of the viruses from Colombia. Similar to the viruses isolated in the Republic of Korea, GVI-1 viruses isolated in China also showed an affinity for the respiratory tract of chickens, which differed from one of the deduced parental viruses, the GI-19 strain. This difference may be due to recombination events that occurred in the genomes of the GVI-1 viruses, resulting in the replacement of the spike gene sequences in an YX10-like strain of GI-19 lineage. • GVI-1 viruses likely originated from Columbia. • GVI-1 strains isolated in China may be derived from recombination events between GI-19 and CO8089L/CO8091L-like viruses. • GVI-1 viruses exhibited variable antigenicity. • GVI viruses showed an affinity for the respiratory tract of chickens. [ABSTRACT FROM AUTHOR]

Green manure planting can reduce the intensity of soil use, while improving farmland productivity in double-cropping systems. However, only few studies have focused on the impacts of green manure application under different fertilization management options on succeeding crop yield and soil organic carbon (SOC) process. A three-year field experiment was conducted with a winter smooth vetch-summer maize cropping system to evaluate the effects of green manure with different chemical fertilizers on soil physiochemical properties, SOC fraction, enzyme activities and maize yield. Total eight treatments were compared including different combinations of green manure and chemical fertilizers (i.e., nitrogen and phosphorus fertilizers) in the smooth vetch phase and maize phase. The results showed that compared to the control, green manure incorporation increased the soil moisture, total nitrogen, total phosphorus, basal respiration, SOC and its labile fractions, and enzyme activities, especially for the treatments of green manure with fertilization. However, the soil pH and bulk density decreased due to green manure application. Maize yield increased 34 %-53 % after green manure application, and was found to be significantly and positively correlated with soil carbon process (P < 0.05). Moreover, SOC and its labile fractions, and total nitrogen were observed as the main drivers of the maize yield. Variation partition analysis demonstrated that soil biochemical properties and their interaction with green manure by fertilization caused variations in SOC fractions. Further, structural equation models indicated that both balanced fertilization practices had positive effects on maize yield and soil carbon process via changes in SOC fractions and C cycling-related enzyme activities, respectively. In addition, the amount balance of chemical fertilizer positively impacted the soil carbon process by regulating SOC fractions through enzyme activities. These findings provide important guidance for applying optimal fertilization management in the green manure phase to improve succeeding crop yield and soil quality as well as to mitigate the adverse impacts of chemical fertilizers. The study will be equally illuminating for other green manure-crop rotation systems., Competing Interests: Declaration of competing interest The authors declared that they have no conflicts of interest to this work. We declare that we do not have any commercial or associative interest that represents a conflict of interest in connection with the work submitted., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Background: Traditional Chinese medicine formula (TCMF) Run-zao-zhi-yang capsule (RZZY) is commonly used in treating itch in China. However, there are few studies on its mechanisms. In this study, we revealed the mechanisms and molecular targets of RZZY for itch by network pharmacology, molecular docking, and in vitro experiments., Methods: The network pharmacology consisted of active ingredient collection, target acquisition, enrichment analysis, biological process analysis, and network construction. Molecular docking was carried out using molegro virtual docker (MVD) software. LPS-induced RAW 264.7 cells were used to evaluate the in vitro anti-inflammatory activity., Results: We collected 483 high-confidence targets that interacted with 16 active compounds of RZZY, including 121 common genes related to itch. 43 important targets and 20 important pathways were identified according to the network and system analysis. Target-pathway network function analysis suggested that RZZY is treated for itch by multiple ways in immune regulation, hormone adjustment, anti-inflammation, and anti-oxidation. Molecular docking results demonstrated that daidzein and formononetin could be closely combined with 4 proteins. In vitro experiments displayed that RZZY, sophocarpine, catalpol, emodin, and daidzein had suppressive effects against TNF-α, IL-1β, or IL-6 production in LPS-induced RAW 264.7 cells. Interestingly, the result of network pharmacology revealed that RZZY might be more suitable for senile pruritus, consistent with the bibliometric analysis of RZZY's clinical indications., Conclusion: This study illustrated the potential mechanisms and molecular targets of RZZY for itch, which may contribute to the proper use of RZZY in clinical practice., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)

Purpose: Potential influences of GRK5 polymorphism on cancer risks have been reported. This study aimed to explore the distribution of GRK5 genotypes and alleles in Chinese breast cancer (BCa) patients, and to analyze the association between GRK5 and BCa risk., Methods: Blood samples were collected from 412 BCa patients and 533 healthy individuals for isolating genomic DNA. GRK5 polymorphisms of Gln41Leu A > T and Arg304His G > A, and their alleles were detected using PCR-RFLP. Their influences on BCa susceptibility and pathological indexes were analyzed using Logistic regression model., Results: No significant differences in age, body mass index (BMI) and smoking status were found between BCa patients and healthy persons, while significant differences were detected in drinking status, family history of cancer, hypertension and diabetes. GRK5Gln41Leu A > T and its allele frequency distribution were correlated to BCa susceptibility, while GRK5 Arg304His G > A was not. Higher risks of GRK5 Gln41Leu A > T and Arg304His G > A indicated a higher susceptibility to BCa. Compared with people carrying 0-1 risk allele, those carrying 2-4 risk alleles of GRK5 Gln41Leu A > T and Arg304His G > A of had a higher susceptibility to BCa, manifesting as worse tumor staging and grading, and higher rates of estrogen receptor (ER) (-), progesterone receptor (PR) (-) and HER2 (-)., Conclusions: Gln41Leu A > T and Arg304His G > A fusion gene polymorphisms of GRK5 are vital genetic susceptibility genes to BCa. Our findings require to be validated in a multicenter study with a high-quality large sample size.

Most cyanobacteria can synthesize the notorious neurotoxin β-methylamino- l -alanine (BMAA) that is transferred and bioaccumulated through natural food webs of aquatic ecosystems and ultimately arises the potential human health risks by the consumption of BMAA-contaminated aquatic products. Fertilization of cyanobacterial composts in farmlands may also lead to BMAA contamination in soil and its possible transfer and bioaccumulation within major crops, thereby threatening human health. In this study, we first detected a high level of BMAA (1.8-16.3 μg g -1 ) in cyanobacterial composts. In order to assess the health risks from cyanobacterial composts, we planted Chinese cabbage, a favourite vegetable in China, in BMAA-contaminated soil (4.0 μg BMAA/g soil) and detected the levels of free and protein-associated BMAA in soil and crop organs during the whole growth cycle by HPLC-MS/MS, respectively. Our results demonstrated that BMAA indeed transferred from soil to root, stem and leaf of Chinese cabbage during the growth cycle. The BMAA level finally accumulated in the edible portions was much higher than the initial level in soil, including 13.82 μg g -1 in leaf and 4.71 μg g -1 in stem. The discovery of the neurotoxin BMAA in this vegetable, an ending in human consumption, not only provides a BMAA transfer pathway in farmland ecosystems, but also is alarming and requires attention due to the potential risk of cyanobacterial composts to human health., (Copyright © 2018 Elsevier Ltd. All rights reserved.)