Northeast Region Of China Research Articles

Associations of trajectories in body roundness index with incident cardiovascular disease: a prospective cohort study in rural China.

The body roundness index (BRI) has good predictive ability for both body fat and visceral adipose tissue. Longitudinal BRI trajectories can reveal the potential dynamic patterns of change over time. This prospective study assessed potential associations between BRI trajectories and incident cardiovascular disease (CVD) in rural regions of Northeast China. In total, 13,209 participants (mean age: 49.0 ± 10.3 years, 6,856 [51.9%] male) were enrolled with three repeated times of BRI measurements at baseline (2004-2006), 2008, and 2010, and followed up until 2017 in this prospective study. Using latent mixture model, the BRI trajectories were determined based on the data from baseline, 2008 and 2010. Composite CVD events (myocardial infarction, stroke, and CVD death combined) was the primary endpoint. Cox proportional-hazards models were used to analyze the longitudinal associations between BRI trajectories and incident CVD. Three distinct BRI trajectories were identified: high-stable (n = 538), moderate-stable (n = 1,542), and low-stable (n = 11,129). In total, 1,382 CVD events were recorded during follow-up. After adjustment for confounders, the moderate-stable and high-stable BRI groups had a higher CVD risk than did the low-stable BRI group, and the HR (95%CI) were 1.346 (1.154, 1.571) and 1.751 (1.398, 2.194), respectively. Similar associations were observed between the trajectories of BRI and the risk of stroke and CVD death. The high-stable group was also significantly and independently associated with CVD, myocardial infarction, stroke, and CVD death in participants aged <50 years. BRI trajectory was positively associated with incident CVD, providing a novel possibility for the primary prevention of CVD in rural regions of China.

Numerical Simulations of Failure Mechanism for Silty Clay Slopes in Seasonally Frozen Ground

Landslide damage to soil graben slopes in seasonal freezing zones is a crucial concern for highway slope safety, particularly in the northeast region of China where permafrost thawing is significant during the spring. The region has abundant seasonal permafrost and mostly comprises powdery clay soil that is susceptible to landslides due to persistent frost and thaw cycles. The collapse of a slope due to thawing and sliding not only disrupts highway operations but also generates lasting implications for environmental stability, economic resilience, and social well-being. By understanding and addressing the underlying mechanisms causing such events, we can directly contribute to the sustainable development of the region. Based on the Suihua–Beian highway graben slope landslide-management project, this paper establishes a three-dimensional finite element model of a seasonal permafrost slope using COMSOL Multiphysics 6.1 finite element numerical analysis software. Additionally, the PDE mathematical module of the software is redeveloped to perform hydrothermal-coupling calculations of seasonal permafrost slopes. The simulation results yielded the dynamic distribution characteristics of the temperature and seepage field on the slope during the F–T process. The mechanism behind the slope thawing and sliding was also unveiled. The findings provide crucial technical support for the rational analysis of slope stability, prevention of sliding, and effective control measures, establishing a direct linkage to the promotion of sustainable infrastructure development in the context of transportation and roadway engineering.

Comparison of the effects of five long‐term land use and management practices on runoff, soil erosion, and nutrient loss under natural rainfall in the Mollisol region of Northeast China

AbstractClarifying the effects of various land‐use and management practices on soil erosion and nutrient loss of sloping land can help optimize land use patterns and management strategies. This study assessed the effects of five long‐term land‐use and management practices on runoff, soil erosion, and nutrient losses. Field data from runoff plots established in 2006 in bare land (BL), natural vegetation restoration (NVR), no tillage (NT), reduced tillage (RT), and conventional tillage (CT) were used in two seasons of natural rainfall (from July to September in 2021 and 2022). The results indicated that the runoff depth (RD) was 84.1% and 43.2%–81.7% lower, the sediment yield (SY) was 99.9% and 96.9%–99.8% lower, the total nitrogen (TN) loss was 99.1% and 93.1%–98.6% lower, and the total phosphorous (TP) loss was 99.8% and 96.7%–99.7% lower in the NVR and three tillage practices, respectively than in the BL. The RD, SY, and nutrient losses were significantly lower in NT than in RT and CT. The TN loss in runoff contributed to 88.3% and 87.6% of the TN loss in the NVR and NT, respectively, whereas the TN loss in the sediment (TN‐SL) for BL accounted for 94.7% of the TN loss in BL. Meanwhile, most of the TP loss (56.1%–99.7%) was attributed to soil erosion rather than runoff in the five treatments. Furthermore, the effect of runoff and SY on nutrient losses differed significantly for the five land‐use and management practices. The effects of runoff and SY on the TP loss were negligible in the NVR and three tillage treatments. However, the effects on the TN loss were larger. Rainfall erosivity had the largest effect on runoff, SY, and nutrient loss in the five treatments. Our findings can help land managers to select sustainable measures to control soil and nutrient losses in sloped farmland in Northeast China.

Enhancing Soybean and Maize Yields through Improved Nitrogen and Soil Water Use Efficiencies: A 40-Year Study on the Impact of Farmyard Manure Amendment in Northeast China.

The combined application of manure and chemical fertilizers has been recognized as a critical factor driving significant changes in crop yield and nutrient use efficiency, holding the potential to optimize agricultural management to achieve high yields. In this 40-year study, we investigated the effect of manure amendment on soybean and maize yields, water and nitrogen use efficiencies (WUE and NUE), and water and mineral N storage at 0-100 cm soil depths from 2017 to 2018 to explore the optimization of fertilization management strategies for soybean and maize production in Northeast China. To elucidate the impact of chemical fertilizers and manure, twelve treatments-control (CK); single N fertilizer at a low rate (N1) and that at a high rate (N2); N1, phosphorus (P), and potassium (K) fertilizer (N1PK); manure alone at 13.5 and 27 t ha-1 (M1 and M2); and those combined with N, P, or K fertilizer (M1N1, M1N2, and M1N1PK and M2N1, M2N2, and M2N1PK)-were selected and studied. The results showed that long-term amendment with manure significantly increased crop biomass and yield in the soybean-maize-maize rotation system. Combining with manure increased the WUE, the partial factor productivity of N fertilizer (PFPN), and N physiological efficiency (PEN) in both the soybean and maize seasons; conserved soil water (mainly at 40-60 cm); and increased soil N retention (in the upper 60 cm layer), which reduced the risk of N leaching, with a better effect being observed after the application of 13.5 t ha-1 manure. These results provide insight into the potential of using fertilization management strategies that include amendment with 13.5 t ha-1 manure in combination with N, P, and K fertilizer in the maize season and only chemical fertilizer in the soybean season, as these results indicate that such strategies can achieve high yields and be used to implement agricultural sustainable development in brown soil regions in Northeast China.

Refined Evaluation of Climate Suitability of Maize at Various Growth Stages in Major Maize-Producing Areas in the North of China

The Northeast region of China and Huang Huai Hai (3H) region are vital maize production bases in northern China that are crucial for national food security. The absence of phenological data hinders a detailed assessment of the alignment between maize development stages and climatic resources. This study combines the authors’ maize phenology data with climate suitability modeling to evaluate maize’s climate suitability at different developmental stages in both regions. This study shows that during the maize growth cycle, the average temperature, precipitation, sunshine, and comprehensive climate suitability were 0.77, 0.49, 0.87, and 0.65, respectively, in the Northeast. In contrast, the average temperature, precipitation, sunshine, and comprehensive climate suitability in the 3H region were 0.98, 0.53, 0.73, and 0.70, respectively. Precipitation is a major factor influencing maize growth, with temperature and sunshine impacting growth differently across regions. Temperature significantly affects maize in the Northeast, while sunshine plays a greater role in the 3H region. The Northeast is suitable for drought-resistant maize varieties, and implementing a late harvest policy in Liaoning could enhance maize yield. The 3H region generally has favorable climatic conditions. Apart from certain parts of Henan needing drought-resistant varieties, areas with ample growing seasons can adopt long-duration varieties to maximize thermal resource utilization. Our results have important implications for optimizing maize planting strategies and enhancing regional resilience, aiming to assess meteorological factors’ impact on maize growth in key production areas.

A comparative study of grain quality and physicochemical properties of premium japonica rice from three typical production regions.

Grain quality indicates rice commodity value. This research compared grain quality and physicochemical properties of premium japonica rice from three production regions, Yangtze River downstream of China (YRDCN), Northeast region of China (NECN) and Japan. Results showed that there were distinct quality and physicochemical characteristics variance among the three groups of japonica rice, while CVs of most quality parameters from low to high was Japan, YRDCN and NECN. YRDCN rice presented obvious lower apparent amylose content (AAC) and ratio of each chain-length sections of amylopectin, and showed higher protein contents especially glutelin and ratio in short and intermediate amylopectin molecules. Among three rice groups, YRDCN rice presented weaker appearance, whereas did not show inferior cooking and eating properties, which was primarily linked to lower AAC. Rice AAC and starch fine structure significantly correlated with pasting parameters, swelling power and solubility, while protein content had close relation with taste analyzer parameters. Results of this study indicated improvement direction for japonica rice of YRDCN, and also provided reference for consumers' rice purchasing selection in accordance with individual taste preference.

Screening and evaluating microorganisms with broad-spectrum biogenic amine-degrading ability from naturally fermented dry sausage collected from Northeast China

This study aimed to screen autochthonous strains with broad-spectrum biogenic amine (BA) degradation ability from traditional dry sausages and to evaluate their BA-degrading ability in dry sausages. A total of 120 strains were isolated from dry sausages collected from various regions in Northeast China, and 35 of 120 isolates were identified as non-BA producing strains by the in vitro agar method. The random amplified polymorphic DNA polymerase chain reaction technique genotyped these 35 isolates into 18 biotypes. Moreover, high performance liquid chromatography (HPLC) quantification showed that six strains (Latilactobacillus sakei MDJ6; Lactiplantibacillus plantarum SH7; Weissella hellenica DQ9; Staphylococcus saprophyticus JX18 and SYS8; and Macrococcus caseolyticus SYS11) of the 18 biotypes exhibited broad-spectrum BA-degrading ability, all of which had various levels of amine oxidase activity with monoamine oxidase and diamine oxidase activities ranged of 6.60–619.04 and 26.32–352.81 U/mg protein, respectively. These six strains were subsequently inoculated into dry sausages and the results showed that they exhibited varying degrees of BA-degrading ability, of which strain Lat. sakei MDJ6 allowed to have less BA production on dry sausage with a final concentration of 61.33 mg/kg.

Change Characteristics of Rainfall Erosivity in the Black Soil Region in Northeast China from 1961 to 2020

Change Characteristics of Rainfall Erosivity in the Black Soil Region in Northeast China from 1961 to 2020

Removal of Crop Ion Components in Relation to Mollisol Acidification under Long-Term Management

Crop removal of cations and anions is one of the main factors causing soil acidification. Mollisols, also known as black soils, which are inherently neutral soils, have been acidified due to irrational land use. However, the magnitude of acidification of black soils in relation to crop removal under crop rotation and field management remains unclear. In this study, we collect soil samples from 9- and 10-year long-term trials with seven treatments of soybean and corn monoculture, and corn–soybean rotation under different fertilization or straw return in the Mollisol region of Northeast China. Total removal of cations and anions is 371–508 and 92–125 kg ha−1 in corn but 166–250 and 56–82 kg ha−1 in soybean, which leads to the production of 7.06–10.2 kmol ha−1 H+ for corn and 4.43–5.77 kmol ha−1 H+ for soybean. Among the four cations (K+, Ca2+, Na+, and Mg2+) analyzed in different tissues of crops, K+ contributes more to the total H+ production, where K+ in corn stem contributes more than 55% H+, while K+ in soybean seed contributes more than 64% H+. The sum of Ca2+ and Mg2+ removal for soybean is 37.6–66.9 kg ha−1, 1.26–2.07 times (p &lt; 0.05) greater than for corn. Net H+ produced by corn and soybean removal may potentially lead to a soil acidification of 0.053–0.074 and 0.032–0.045 year−1 units pH, respectively. The greater the corn or soybean biomass, the higher the net H+ production. Continuous soybean and combination of chemical fertilizer for corn but no chemical fertilizer for soybean reduce the soil pH buffering capacity (pHBC), while other treatments increase the soil pHBC, but there is no effect for continuous corn. Compared to normal corn–soybean rotation, soil pH in 9-year continuous corn declines from 5.76 to 5.63, while 10-year continuous soybean declines from 5.68 to 5.43 (p &lt; 0.05). However, soil pH with chemical fertilizer for corn and dairy manure for soybean increases by 0.60 and 0.89 units (p &lt; 0.05). Changes in pH might not be fully related to crop ion removal. Manure application with crop rotation is an effective approach to alleviate soil acidification.

Decreased microbial phylogenetic diversity and community stability due to less bioavailable carbon and greater oxygen supply in Mollisols along a cultivation chronosequence

Soil microorganisms support multiple agroecosystem functions, but responses of the microbiome to prolonged agricultural land-use and underlying mechanisms remain poorly understood. In this study, upland soils in the Mollisol region of Northeast China were selected along a 100-year cultivation chronosequence to examine the effects of intensive agriculture on the diversity, composition and co-occurrence network of bacterial and fungal communities. To elucidate the determinants driving the dynamics and interactions of microbial communities, the researchers quantified the functional groups and bioavailable fractions of soil organic carbon, and estimated the microenvironments including soil texture and oxygen availability. Our findings revealed that fungal diversity and community stability decreased over cultivation time, while that of bacteria showed a less significant decline. The increased oxygen availability and decreased soil carbon supply, particularly polyphenols, jointly drove the dynamics in the composition and stability of the microbial communities. Crucially, these microbial responses were significantly regulated by interspecific associations. Phylotypes showing stronger responses to changes in oxygen availability and carbon supply demonstrated a higher level of connectivity within co-occurrence networks, signifying their potential role as pivotal “hubs” in transmitting the environmental influences across the entire community via interspecific associations. Moreover, the decline in fungal diversity over longer cultivation periods could liberate more survival niches for bacterial species through fungi-bacteria associations, thereby bolstering the stability of the bacterial community. Overall, this study accentuates the pivotal role of trophic associations in facilitating the oxygen and carbon-induced succession of belowground microbiota in long-term cultivated Mollisols. In view of the agricultural intensification propelled by the increasing demand for crop production, these findings suggest strategies integrating improvements in soil structure and carbon with microbial processes to ensure the sustainability of agroecosystem functions.

China's energy-water-land system co-evolution under carbon neutrality goal and climate impacts

China's 2060 carbon neutrality goal has significant implications for energy, water, and land systems. However, the multi-sector dynamics among China's energy-water-land system have rarely been examined explicitly. This study adopts an integrated assessment framework to simulate China's energy-water-land system co-evolution under alternative carbon neutrality scenarios and climate impacts. Results show that although the net zero emission target provides the incentive for the energy system to move away from fossil fuels, total water withdrawal will increase due to the deployment of nuclear, bioenergy, and coal power plants with carbon capture and storage. Diversifying the negative emission technologies, by leveraging direct air capture technology, can alleviate the potential water stress and land use conflicts, which would otherwise be exacerbated by large-scale deployment of afforestation and bioenergy with carbon capture and storage. Northwest and northeast regions of China are the hotspots experiencing water withdrawal increases, while Bohai Rim and coastal regions are identified to experience fierce land competition. This study demonstrates the potential for general applicability to carry out resource planning and policy evaluation from the multi-sector coordination perspective.

Winter Cover Crops Affect Aggregate-Associated Carbon, Nitrogen and Enzyme Activities from Black Soil Cropland

The thinning, leaning, and hardening of arable land in the black soil region of Northeast China has brought serious challenges to the sustainable development of agriculture. It is of great significance to explore suitable conservation tillage for the conservation and sustainable utilization of black soil resources actively. The topsoil of the cropland in the northeastern part of the Songnen Plain with winter fallow (CK), planted alfalfa, and planted winter wheat was used as the research object to analyze the changes in the soil aggregate composition, nutrients, and enzyme activities before and after freeze–thaw, respectively, and to investigate the effect of winter cover crops on the improvement of the quality of the black soil cropland. Compared with the winter fallow field, (1) planting alfalfa significantly increased the mechanical stability of 1–2 mm and 0.25–1 mm particle size aggregates (about 3 times and 25 times over), and planting winter wheat increased the water stability of 0.25–1 mm particle size aggregates significantly (2.7 times over); (2) planting alfalfa and winter wheat increased the soil C/N ratio of &gt;2 mm and 1–2 mm particle size aggregates, and the increment in the C/N ratio in &gt;2 mm particle size aggregates remarkably increased, by 203.6% and 362.7%, respectively; (3) planting alfalfa significantly enhanced the soil invertase activity and urease activity in &gt;2 mm and 0.25–1 mm particle size aggregates, and planting winter wheat significantly enhanced the catalase activity in 0.25–1 mm particle size aggregates. In conclusion, planting winter cover crops during the winter fallow period can maintain and promote the mechanical and water stability of medium and large (0.25–1 mm,1–2 mm) soil aggregates, increase the carbon content and C/N ratio of larger (1–2 mm, &gt;2 mm) aggregates, and enhance the enzyme activity of small and medium (0.25–1 mm, &lt;0.25 mm) aggregates to varying degrees. The results of the study can provide a reference for the promotion of basic research on and technology for winter cover crops in the black soil region.

Integrated Use of GIS and USLE Models for LULC Change Analysis and Soil Erosion Risk Assessment in the Hulan River Basin, Northeastern China

The Hulan River Basin is located in the black soil region of northeast China. This region is an important food-producing area and the susceptibility of black soil to erosion increases the risk of soil erosion, which is a serious environmental problem that affects agricultural productivity, water supply, and other important aspects of the region. In this paper, the changes in LULC (land use and land cover) in the basin between 2001 and 2020 were thoroughly analysed using GIS (geographic information system) and USLE (universal soil loss equation) models. The soil erosion risk in the Hulan River Basin between 2001 and 2020 was also studied and soil erosion hot spots were identified to target those that remained significant even under the implementation of soil conservation measures. Precipitation data were used to obtain the R factor distribution, LULC classification was adopted to assess the C factor distribution, soil data were employed to estimate the K factor distribution, DEM (Digital Elevation Model) data were used to generate an LS factor map, and slope and LULC data were considered to produce a P factor distribution map. These factors were based on the model parameters of the USLE. The findings of LULC change analysis over the last 20 years indicated that, while there have been nonobvious changes, agricultural land has continued to occupy the bulk of the area in the Hulan River Basin. The increase in areas used for human activities was the most notable trend. In 2001, the model-predicted soil erosion rate varied between 0 and 120 t/ha/yr, with an average of 4.63 t/ha/yr. By 2020, the estimated soil erosion rate varied between 0 and 193 t/ha/yr, with an average of 7.34 t/ha/yr. The Hulan River Basin was classified into five soil erosion risk categories. Most categories encompassed extremely low-risk levels and, over the past 20 years, the northeastern hilly regions of the basin have experienced the highest concentration of risk change areas. The northeastern hilly and mountainous regions comprised the risk change area and the regions that are most susceptible to erosion exhibited a high concentration of human production activities. In fact, the combined use of GIS and USLE modelling yielded erosion risk areas for mapping risk classes; these results could further assist local governments in improving soil conservation efforts.

Phylogeographic structure and putative migration pathway of Sogatella furcifera in China based on microsatellite markers

AbstractThe white back planthopper (WBPH), Sogatella furcifera (Horváth) (Hemiptera: Delphacidae), is an important destructive rice pest in Asia that has caused serious economic losses in the main rice‐producing areas of China. To effectively manage this rice pest, it is necessary to investigate its genetic variation and genetic structure and speculate the migration route in China. In this study, we used 12 nuclear microsatellite loci to analyse the genetic variation, gene flow and genetic structure of WBPH in 25 geographic populations in China. Overall, high levels of genetic diversity and genetic differentiation among most populations were detected. Neighbour‐joining dendrograms, STRUCTURE and principal coordinate analysis (PCoA) revealed three genetically distinct groups and exhibited an admixed phylogeographic structure. There was a significant low positive correlation between genetic and geographic distances (r2 = 0.105, p = 0.001), which indicated the role of geographic isolation in the genetic structure of WBPH. Migrant routes detection indicated frequent gene flow exchange between North China and Central China, and low bidirectional gene flows between Northeast China and other regions were detected. Accordingly, this study provides useful data for resolving the genetic relationships and large‐scale migration route of the WBPH and thus contributes to developing more effective management strategies for controlling this pest.

Regional differences of physical fitness and overweight and obesity prevalence among college students before and after COVID-19 pandemic since the "double first-class" initiative in China.

Physical fitness has been widely recognized as a powerful marker of health in children and adolescents, and it negatively affected by the COVID-19 pandemic. The construction of world-class universities and first-class disciplines, known as the "Double First-Class" Initiative (DFC), is a major commitment made by the Chinese government to adapt to changes in the educational environment, both domestically and internationally, in order to promote the development and practice of international higher education. The aim of the study was to look deep into the regional differences of physical fitness and overweight and obesity prevalence among college students before and after the COVID-19 pandemic since the DFC. The original physical fitness parameters of students from 10 DFC universities and colleges in Central South China were downloaded from the official website of Chinese National Student Physical Fitness Database (CNSPFD) and then divided into 3 groups based on the pandemic periods: pre-pandemic (2019), the first year after pandemic outbreak (2020), and the second year after pandemic outbreak (2021). All the data were stored in Excel 2010, analyzed by SPSS 17.0, and plotted with ArcGIS 10.4. The total "fail" percentage (from 9.19% in 2019 to 12.94% in 2021) and the prevalence of overweight and obesity in boys (from 22.53 to 29.25% in 2021) exhibited a continuous increase year by year, and among all the physical fitness indicators the score of strength in boys and endurance quality in all individuals were the lowest in overweight and obesity groups. Students with 'fail' rate developed from northern and northeastern province to southern areas from 2019 to 2021. For grade 2019th, overweight and obesity students who also failed the test had covered nationwide and the most affected areas including northeast, east, as well as central north in senior year. The distribution of overall fitness assessments in Hubei province was in accordance with the national data, and the overall scoring growths in both class of 2021st and 2022nd were measured with a negative increase (p < 0.01). The government and related functional departments should take into consideration the student regional sources, especially in western and northeast regions of China, and school polices and physical education (PE) teachers should pay more attention to put training efforts on endurance for all adolescents and strength for boys and the group of overweight and obesity who also failed in the standard test, when designing specific interventions to promote physical health and counteract the negative effects of COVID-19 pandemic in college students.

A regime shift between soil moisture and temperature in the 1950s over the permafrost region of Northeast China

AbstractPermafrost is one of the essential carbon pools in the world. Due to limited studies on historical soil moisture changes and the coupling relationship between soil moisture and temperature in permafrost regions, significant uncertainty exists in the carbon loss in permafrost predicted by different models under global warming scenarios. Based on the tree‐ring width chronology of Pinus sylvestris var. mongholica Litv. growing in the southern edge of the Eurasian continuous permafrost zone, we reconstructed the summer (June–September) 0–1 m soil moisture variations from 1705 to 2009, which could explain 45.6% of the variance in the observed soil moisture. Overall, local precipitation and temperature exhibited statistically significant positive feedback (p &lt; 0.001) to soil moisture before the 1950s, indicating that the warm/humid climate pattern was conducive to soil moisture conservation before the Anthropocene Epoch. However, the effect of temperature on soil moisture has shifted suddenly to negative since the 1950s, implying that the positive soil moisture‐temperature relationship during the past three centuries has been disrupted by the unprecedented warming in the Modern Warm Period. Furthermore, we found that the temporal relationship of the soil moisture‐temperature (15‐year sliding correlation) in the study area is negatively regulated by the global mean temperature variations (p &lt; 0.01). The regime shift between soil moisture and temperature might be attributed to the superimposed influence of natural and anthropogenic factors since the 1950s. Although the warming leads to the melting of the permafrost layer, and thus the increase in soil moisture content, the enhanced evapotranspiration caused by warming up results in more water loss and drier soil. This study provides historical evidence of shifted soil moisture‐temperature coupling in the permafrost zone, warning that soil moisture in the permafrost region may further decline under global warming scenarios, thereby affecting vegetation growth and forest carbon sequestration potential.

Strip-Till Farming: Combining Controlled-Release Blended Fertilizer to Enhance Rainfed Maize Yield While Reducing Greenhouse Gas Emissions

The two major concerns of sustainable agriculture are safeguarding food security and reducing greenhouse gas emissions. Studies on the performance of strip-till with controlled-release blended fertilizer on rainfed maize grain yield, greenhouse gas emissions, and net ecosystem economic budget are scarce in the hilly region of northeast China. In this study, the differences between strip-till (RST) and conventional ridge cropping (CP), straw off-field no-tillage (NT), and no-tillage with straw mulching (RNT) were comparatively investigated in the conventional fertilizer (Sd) mode. And meanwhile, four fertilization modes were also set up under strip-till (RST): conventional fertilization (Sd), controlled-release nitrogen fertilizer blended with normal urea 3:7 (30%Cr), controlled-release nitrogen fertilizer blended with normal urea 5:5 (50%Cr), and no-nitrogen fertilization. We analyzed maize yield, greenhouse gas emissions (GHG), greenhouse gas intensity (GHGI), net income and net ecosystem economic budget (NEEB) for different treatments. The results showed that, under conventional fertilizer (Sd) mode, the maize yield of RST increased by 4.2%, 6.0% and 7.2% compared with NT, CP and RNT and the net income increased by 7.0%, 9.7% and 10.0%, respectively. Compared with CP and NT, although RST increased CO2 and N2O emissions, the GHGI of RST was not significantly different from CP and NT, and was 8.0% lower than that of RNT. The NEEB of RST increased by 6.8%, 9.7% and 11.0%, respectively, compared with NT, CP and RNT. Under strip-till, compared with 30%Cr and Sd, the yield of 50%Cr increased by 4.0% and 9.2% and the net income increased by 3.5% and 6.9%, respectively. There was no significant difference in GHGI between 50%Cr and 30%Cr, and 50%Cr decreased by 10.4% compared with Sd. The NEEB of 50%Cr increased by 3.8% and 7.4% compared to 30%Cr and Sd. Strip-till combines controlled-release nitrogen fertilizer blended with normal urea 5:5 (50%Cr) and can be applied as a sustainable strategy to improve the economic efficiency of maize and reduce environmental costs in the hilly region of northeast China.

A115: Revision of the Chinese Version of Physical Self-Description Questionnaire-Short for Middle School Students

Purpose: The Physical Self-Description Questionnaire -Short (PSDQ-S) is one of the world's recognized effective tools for measuring Physical Self-Concept (PSC). However, Latent profile analysis of the physical self-description among Chinese adolescents only supported the 3-dimensional model of PSDQ-S, that is, it could only distinguish the Physical Activity (PA), Appearance, and Body Fat of Chinese children and adolescents, but could not effectively distinguish the 8 dimensions of Coordination, Flexibility, Strength, Endurance, Sport, Global Physical, Health, and Global Esteem. It cannot meet the needs of PSC measurement in the field of sports psychology in China. The purpose of this study was to revise the PSDQ-S for Chinese middle school students, and to test its reliability, validity, and gender measurement equivalence in Chinese middle school students. Methods: A stratified random cluster sampling method was used to conduct a questionnaire survey on the Chinese version of PSDQ-S. 2505 middle school students in grades 7-12 (12-18 years old) were selected from seven administrative geographic regions of North China, Northeast China, East China, Central China, South China, Southwest and Northwest China, among which 1239 were male subjects, with an average age of (15.07±1.93) years, Female subjects were 1266, with an average age of (15.02±2.04) years. SPSS 24.0 and Mplus 8.3 were used for data analysis. Results: Eight common factors were extracted by exploratory factor analysis, and the cumulative variance interpretation rate was 79.45%. Confirmatory factor analysis support 8 factor model hypothesis (χ2 / df = 1.846, CFI = 0.939, TLI = 0.929, SRMR = 0.050, RMSEA = 0.061). The 8 dimensions were Physical Activity, Appearance, Body Fat, Flexibility &amp; Coordination, Endurance, Sport, Global Physical and Health. The average variance extraction of each factor of the Chinese version PSDQ-S convergence validity index was greater than 0.50, and the combination reliability was greater than 0.60. The gender equivalence hypothesis was established. Conclusions: The revised Chinese version of PSDQ-S has good reliability, validity, and gender equivalence. It can be used as a measurement tool of PSC of Chinese middle school students.

The Relationship between County-Level Population Shrinkage and Food Security from the Perspective of Spatial Patterns and Processes—A Case Study from the Northeast Region of China

The Relationship between County-Level Population Shrinkage and Food Security from the Perspective of Spatial Patterns and Processes—A Case Study from the Northeast Region of China

Influences of mechanized tillage and sowing modes on soil physical properties, soybean yield and economic benefits in mollisols region of Northeast China

Influences of mechanized tillage and sowing modes on soil physical properties, soybean yield and economic benefits in mollisols region of Northeast China