Effects of green manure mulching on soil aggregates and organic carbon fractions in orchards.

Green manure mulching is a sustainable soil management model for orchards. We conducted an experiment with four different green manure treatments, (T), (T), (T), and a mixed sowing of , and (T), with clear tillage as control, to investigate the effects of green manure mulching on soil aggregates and organic carbon fractions in a citrus orchard. The results showed that: 1) Green manure mulching significantly enhanced the distribution and stability of soil aggregates.

Inversion of organic carbon content in calcareous soil in karst area based on hyperspectral and multispectral fusion.

Organic carbon, as one of the important components of soil, is of great significance in assessing soil quality and stability. In karst areas, understanding the distribution characteristics of soil organic carbon content can identify potential soil erosion risk areas and provide a scientific basis for optimizing land use and formulating effective soil and water conservation measures. We collected limestone soil samples under different land use types in Guinan karst, captured soil color images by using five smartphones to extract soil color parameters, and used a spectrometer to obtain soil spectral information.

Safety and Immunogenicity of the Tetravalent Recombinant COVID-19 Protein Vaccine SCTV01E in Children and Adolescents Aged 3 to 17 Years: A Randomized, Double-Blind, Placebo-Controlled Phase 2 Clinical Trial.

: SCTV01E is a tetravalent recombinant COVID-19 vaccine authorized for emergency use in China for adults 18 years and older but not for those under 18. : This Phase 2 trial assessed the safety and immunogenicity of SCTV01E in healthy children and adolescents aged 3 to 17 years, to establish immunobridging with that observed in adults from the efficacy pivotal trial (NCT05308576). : Participants were randomly assigned to receive either 30 µg of SCTV01E or a placebo.

Combined role of ground cover management in altering orchard surface‒subsurface erosion and associated carbon-nitrogen-phosphorus loss.

The combined role of ground cover management in controlling soil erosion and nutrient loss from new orchards is still less understood. In this study, four ground cover management practices, orchard with grass cover (OG), orchard with interplant cover (OI), orchard with straw cover (OS), and orchard with bare ground (OB), were designed to identify their impacts on soil erosion and associated carbon-nitrogen-phosphorus loss in new orchards by rainfall simulation tests with rainfall intensities of 60, 90, and 120 mm h and 90 min rainfall duration. The results showed that OS had the lowest surface flow coefficient (6.

[Development law of soil cracks in karst peak-cluster depressions under dry and wet alternations].

In an experiment with alternating dry and wet conditions of soil in cultivated land, orchards and forest lands with limestone and dolomite in karst peak depression, combined with digital image processing technology, we investigated the development law of soil surface cracks under alternating dry and wet condition. The results showed that with the alternation of wet and dry, the average width of cracks decreased at a fast-slow-slower rate, with an order of limestone > dolomite under the same land use, and orchard > cultivated land > forest soil under the same soil-forming parent rock. In the first four dry and wet alternations, the degrees of soil fragmentation and connectivity were higher in dolomite development than in limestone, with significant differences in fracture development rose diagrams.

[Spatial variations and the key driving factors of soil losses on dolomite slopes].

We selected a typical dolomite slope and set up three micro-plots (projection length was 2 m, width was 1.2 m) on the upper, middle, and lower slopes to analyze the variations of soil losses and the key influencing factors during two hydrological years (2020-2021). The results showed that soil losses at different slope positions on dolomite slopes followed an order of semi-alfisol in lower slopes (386 g·m·a) > inceptisol in middle slopes (77 g·m·a) > entisol in upper slopes (48 g·m·a).

Study on the inhibition mechanism of eucalyptus tannins against Microcystis aeruginosa.

Microcystis aeruginosa is the competitively dominant algal species in eutrophic waters and poses a serious threat to the aquatic ecological environment. To investigate the effects of eucalyptus tannins (TFL) and black water in eucalyptus plantations on M. aeruginosa, this study exposed M.

Acute toxicity of eucalyptus leachate tannins to zebrafish and the mitigation effect of Fe on tannin toxicity.

Fish ponds polluted by the black water of eucalyptus forests (formed by the complexation of eucalyptus tannins with Fe) have experienced fish deaths. However, the toxicity of the components of black water is still unclear. To study the acute toxicities of eucalyptus leachate tannins to fish, their changes in the presence of Fe, and the underlying mechanisms, the static bioassay test method was adopted for acute exposure testing of zebrafish.

Soil aggregate stability and its response to overland flow in successive Eucalyptus plantations in subtropical China.

Soil aggregates constitute the basic units of the soil structure, and soil aggregate stability is an important indicator of soil erodibility. Successive planting of fast-growing plantations can change the erosion resistance of the soil under rainfall conditions. Pure Eucalyptus plantations in this study (first- to fourth-generations, i.

[Effects of plantation on aggregate distribution and stability of lateritic red soil in south subtropical China].

We examined the stability of soil aggregates in five typical plantations, ., × plantation, plantation, plantation, plantation and plantation, in the south subtropical China by the Elliott wet sieving and Le Bissonnais (LB) methods. The results showed that the content of water stability aggregate (WR) was more than 62.

[Characteristics of soil saturated hydraulic conductivity on different positions and their controlling factors of granite collapsing gullies].

Collapsing gully is a common phenomenon of hydraulic-gravity combined soil erosion in granite hilly area of south China. The study aimed to explore the relationship between soil hydraulics pro-perties and erosion mechanism and the intrinsic controlling factors. The active, semi-stable, and stable types of granite collapsing gullies in southeastern Guangxi were selected to examine the spatial variation of soil saturated hydraulic conductivity and identify the influencing factors.

Occurrence patterns of black water and its impact on fish in cutover areas of Eucalyptus plantations.

Black runoff occasionally flows from cutover areas of Eucalyptus plantations, polluting rivers and ponds, and resulting in fish death in severe cases. However, the occurrence patterns and environmental impacts of this black water remain unclear. Herein, we analyzed the major characteristics of black water at the occurrence sites, tested the complexation reaction of ground eucalyptus leaves with a solution of Fe, and determined the color and absorbance of the complex solution.

Effect of soil moisture on soil disintegration characteristics of different weathering profiles of collapsing gully in the hilly granitic region, South China.

Collapsing gully erosion is the main important and specific soil erosion type in the red soil region of tropical and subtropical South China. Knowledge of the soil disintegration characteristics within different weathering profiles (surface layer, red soil layer, sandy soil layer and detritus layer) and its relationships with soil particle size distribution and soil properties is important in understanding the mechanism of the forming process and development of the collapsing gully. In this paper, we conducted an experiment on four collapsing gullies located four counties (Tongcheng County, Gan County, Anxi County and Wuhua County) in the hilly granitic region of southern China.

Fractal features of soil particle size distribution under different land-use patterns in the alluvial fans of collapsing gullies in the hilly granitic region of southern China.

Collapsing gullies are among the most severe soil erosion problems in the tropical and subtropical areas of southern China. However, few studies have examined the relationship of soil particle size distribution (PSD) changes with land-use patterns in the alluvial fans of collapsing gullies. Recently, the fractal method has been applied to estimate soil structure and has proven to be an effective tool in analyzing soil properties and their relationships with other eco-environmental factors.