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Introduction: In recent years, nitrogen deposition has constantly continued to rise globally. However, the impact of nitrogen deposition on the soil physicochemical properties and microbial community structure in northern Guangxi is still unclear. Methods: Along these lines, in this work, to investigate the impact of atmospheric nitrogen deposition on soil nutrient status and bacterial community in subtropical regions, four different nitrogen treatments (CK: 0 gN m-2 a-1, II: 50 gN m-2 a-1, III: 100 gN m-2 a-1, IV: 150 gNm-2 a-1) were established. The focus was on analyzing the soil physical and chemical properties, as well as bacterial community characteristics across varying nitrogen application levels. Results and discussion: From the acquired results, it was demonstrated that nitrogen application led to a significant decrease in soil pH. Compared with CK, the pH of treatment IV decreased by 4.23%, which corresponded to an increase in soil organic carbon and total nitrogen. Moreover, compared with CK, the soil organic carbon of treatment IV increased by 9.28%, and the total nitrogen of treatment IV increased by 19.69%. However, no significant impact on the available nitrogen and phosphorus was detected. The bacterial diversity index first increased and then decreased with the increase of the nitrogen application level. The dominant phylum in the soil was Acidobacteria (34.63-40.67%), Proteobacteria, and Chloroflexi. Interestingly, the abundance of Acidobacteria notably increased with higher nitrogen application levels, particularly evident in the IV treatment group where it surpassed the control group. Considering that nitrogen addition first changes soil nutrients and then lowers soil pH, the abundance of certain oligotrophic bacteria like Acidobacteria can be caused, which showed a first decreasing and then increasing trend. On the contrary, eutrophic bacteria, such as Actinobacteria and Proteobacteria, displayed a decline. From the redundancy analysis, it was highlighted that total nitrogen and pH were the primary driving forces affecting the bacterial community composition. [ABSTRACT FROM AUTHOR]

Arthropods play a crucial role in ecological processes and agricultural productivity. Soil physicochemical properties, indicators of soil health, are closely linked to arthropod communities. Gravel-sand mulching, commonly employed in arid farming, initially enhances water retention and temperature regulation but may contribute to land degradation with prolonged use. This study investigated how varying tillage durations affected soil properties and arthropod diversity under gravel-sand mulching. The analysis employed multiple comparison methods, covariance analysis (ANCOVA), non-metric multidimensional scaling (NMDS), and redundancy analysis (RDA). The results indicated that while soil fertility was better preserved in cultivated fields compared to in the desert grassland, arthropod diversity significantly decreased with longer cultivation periods. A total of 1099 arthropods from 79 species were sampled, by Barber trap. The highest diversity was observed in native grassland (NG), with 305 arthropods from 39 species, while tillage 21 years (GPS-21Y) exhibited the lowest diversity, with only 103 arthropods from 6 species. Dominant species included the carnivores Labidura japonica and Cataglyphis aenes. The analysis revealed low similarity in arthropod communities between GPS-21Y and other fields and high similarity in soil physicochemical properties between NG and the transition zone (STZ). RDA showed available potassium (APP) was negatively correlated with arthropod species diversity and concentration, total Nitrogen (TN) was positively correlated with arthropod species diversity but negatively correlated with species concentration, total phosphorus (TP) was negatively correlated with arthropod species diversity and concentration. This study provides insights into the relationship between maintaining soil fertility and supporting arthropod diversity in grassland agriculture. While soil fertility and arthropod diversity were correlated, continuous cropping practices negatively impacted arthropod diversity, offering valuable information for pest management and sustainable agricultural practices. [ABSTRACT FROM AUTHOR]

Crop straw returning to the field is an effective practice for straw utilization to improve soil fertility and sustain crop productivity. However, little information is available about the long-term effects of paddy straw return on soil properties and rice yield under a double-rice system. The objectives of this study were to test the hypothesis of the effects of different amounts of paddy straw returned to the field on soil physicochemical properties and rice yield, and to clarify the correlation between crop yield and soil physicochemical properties as well as quick-acting nutrients under different straw-returning modes. The experiment, initiated in the 2005 rice season, utilized "Xiang 45" and "Xiang 13" long-grained rice cultivars within a double-season rice cropping system. Three straw-returning treatments were implemented: rotary tillage with full rice straw incorporation (RTS), incorporation of one-third of the rice straw (1/3RTS), and incorporation of two-thirds of the rice straw (2/3RTS). This study found that among the three straw return rates, 2/3RTS had the most significant impact on soil physicochemical properties. Soil nitrogen content was identified as a crucial factor influencing soil organic carbon (SOC) accumulation, while pH levels significantly affected rice yield. Straw incorporation effectively increased the content and stocks of SOC. [ABSTRACT FROM AUTHOR]

Copyright of Bulletin of Soil & Water Conservation is the property of Bulletin of Soil & Water Conservation Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Grass cover in orchards has been proposed as a sustainable management system with greater ecological and economic benefits than open pastures. However, few studies have compared the ecological impact of grass-covered orchards with that of traditional tilled systems. Therefore, this meta-analysis was focused on evaluating the ecological benefits of grass cover in orchards on the soil physicochemical properties under different establishment modes and construction period in China. In total, 492 paired data points were extracted from 29 references, and effect values (ES) were calculated to show the effect of grass cover on soil physicochemical properties. The results showed that grass cover in orchards improved soil physicochemical properties by decreasing the soil bulk density (ES: -0.0659) of three soil layers (0–20 cm, 20–40 cm and 40–60 cm depth) and by decreasing soil pH in the alkaline areas (ES: -0.0219) of 0–20 cm and 20–40 cm soil layers. Grass cover in orchards also significantly improved the nutrient contents of the topsoil layer (0–20 cm depth), having the greatest effect on the total nitrogen content (ES: 0.1416), followed by that on the total phosphorus content (ES: 0.1002), and the weakest effect was observed on the total potassium content (ES: 0.0832). Grass cover in orchards significantly increased the soil available nitrogen content at all three soil depths (ES: 0.1608) and the soil available phosphorus content at the 0–40 cm soil depth (ES: 0.0788). However, no significant effect on the soil available potassium content was detected. Grass cover in orchards significantly increased soil organic matter content at all three soil depths (ES: 0.3734; P < 0.01), with the greatest effect occurring in the 40–60 cm soil layer (ES: 0.7972). Subgroup analysis of available nutrients in the 0–20 cm soil layer showed that 2–3 years after grass covering in orchards greatest promoting on the soil available nitrogen (ES: 0.2967) and phosphorus contents (ES: 0.1815), while the soil available potassium content decreased with construction period. In summary, grass cover in orchards has various effects on soil physicochemical properties, and these effects are closely related to soil layer depth, construction period, plant species and geographical region. Moreover, long-term monitoring is required to confirm the ecological influence of diverse types of grasses on soil properties in orchards. [ABSTRACT FROM AUTHOR]

The expansion of Eucalyptus globules boundary plantations (EGBPs) along farm boundaries is considered to have effects on the yield of crops underneath them. We evaluated the orientation and root trenching effect of EGBP on barley yield and soil physicochemical properties in the Gummer District of Central Ethiopia. Two months before sowing, trenches were prepared on each side of the orientation of EGBP at distances of 0.5 m, 1 m, and 1.5 m using a split-split plot design with three replications. At a 1.5 m trench distance, the north-facing field showed 20.4% to 31.2% additional yield increment compared with the south-, east-, and west-facing fields. Additionally, 15.2% to 43% additional yield was observed as the field distance from the EGBP increased from 3 to 12 m. In comparison to un-trenched fields, trenched fields showed 31.9% to 73.4% additional yield variation. Regarding the soil physicochemical properties, the aspect of EGBP had no a significant effect. However, except for the texture, pH, and exchangeable K, the soil OM, TN, available P, and CEC status significantly differed among the trenches. On average, the root trench minimized the field distance effect of EGBP on barley yield by 24%. Tree root trenching is a potential tool for managing below-ground competition. Therefore, establishing a 0.5 m × 0.5 m trench at a 1.5 m distance from the EGBP is vital for maximizing barley yield and increasing land-use efficiency. [ABSTRACT FROM AUTHOR]

BACKGROUND: Crop quality, yield and farmer income are reduced by soil‐borne diseases, nematodes and weeds, although these can be controlled by allyl isothiocyanate (AITC), a plant‐derived soil fumigant. However, its efficacy against soil‐borne pathogens varies, mainly because of its chemical instability and uneven distribution in the soil. Formulation modification is an effective way to optimize pesticide application. We encapsulated AITC in modified diatomite granules (GR) and measured the formulation's loading content and stability, environmental fate and efficacy against soil‐borne pathogens, and its impact on the growth and yield of tomatoes. RESULTS: We observed that an AITC loading content in the granules of 27.6% resulted in a degradation half‐life of GR that was 1.94 times longer than 20% AITC emulsifiable concentrate in water (EW) and shorter than AITC technical (TC) grade. The stable and more even distribution of GR in soil resulted in relatively consistent and acceptable control of soil‐borne pathogens. Soil containing AITC residues that remained 10–24 days after GR fumigation were not phytotoxic to cucumber seeds. GR significantly reduced soil‐borne pest populations, and tomato growth and yield increased as AITC dosage increased. GR containing an AITC dose of 20 g m−2 effectively controlled pathogens in soil for about 7 months and improved tomato yield by 108%. CONCLUSION: Our research demonstrates the benefits of soil fumigation with loaded AITC over other formulations for effective pest control, and improved tomato plant growth and fruit yield. Fumigant encapsulation appears to be a useful method to improve pest and disease control, environmental performance and fumigant commercial sustainability. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Inner Mongolia's grassland is one of the most complete natural grasslands for ecological diversity and biodiversity conservation in the world. However, its degradation has seriously affected the plateau's sustainable development and grassland restoration and reconstruction. To reveal the response of soil-plant synergistic relationship to different degrees of degradation, we selected three degrees of degradation (total coverage of vegetation:20%-30%, LD), moderate degradation (total coverage of vegetation:10%-20%, MD) and severe degradation (total coverage of vegetation:<10%, SD) on typical grasslands in Inner Mongolia (3 transects per degraded plot, three replicates per transect, a total of 27 quadrats). Correspondence between vegetation and soil under different degrees of degradation was obtained by correlation analysis. Soil physical properties influence degradation degree much more than soil depth. Among them, the most obvious total nitrogen (TN) decreased by 251.63% and 125.81% under moderate degradation (MD) and severe degradation (SD) respectively, compared with light degradation (LD). When the degree of degradation increased, the number of species reduced, and when compared to light degradation, moderate degradation and severe degradation decreased by 52.38% and 66.67%, respectively. The declining trend in the number of species was also indicated by Simpson, Margalef, and Shannon-Winener in addition to the Pielou index. The synergy between plant diversity index and soil organic matter (SOM), available potassium (AK) and bacteria was relatively strong. [ABSTRACT FROM AUTHOR]

Summary: Maize is an important cereal crop in sub-Saharan Africa (SSA). Plant-parasitic nematodes significantly impact maize production. However, research on maize nematodes in SSA is limited. The current study aimed to assess the occurrences and densities of nematodes associated with maize and to assess the correlation of some soil physicochemical properties with nematodes in southern and southwestern Ethiopia. One hundred and eighty-six soil and root samples were collected from 62 maize fields (31 from Hawassa Zuria and 31 from Mana districts). Eleven plant-parasitic nematode genera were identified. The most important genera of plant-parasitic nematodes identified were Meloidogyne and Pratylenchus , followed by Helicotylenchus and Tylenchorhynchus. The nematodes Pratylenchus and Criconemoides were significantly and positively associated with pH, soil organic carbon (SOC) and soil organic matter (SOM). Additionally, Tylenchorhynchus , Pratylenchus and Rotylenchulus were significantly positively correlated with soil available phosphorus (SAP). However, Criconemoides and Meloidogyne had a strong negative correlation with soil bulk density (SBD). This study provides useful baseline information on maize-associated nematodes, and will be useful for agricultural policy makers, private farmers, non-governmental organisations and agricultural extension workers enabling them to establish sustainable maize nematode management strategies. [ABSTRACT FROM AUTHOR]

15 soils were sampled in the present study to investigate the content of soil organic carbon (SOC) and soil aggregates, on the soil oxidant requirement (SOD) that used in the chemical oxidation remediation technology. Alkali-activated sodium persulfate was selected as the oxidant. The result showed that microaggregates (<250 μm) contained 70% of SOC. A significant positive correlation was found between the value of SOD and the content of SOC of the bulk soil. Furtherly, SOD was positively correlated with SOC content of three different aggregates of soils (2 000-250 μm, 250-53 μm and <53 μm), and the smaller the soil aggregates, the higher the significance value. Therefore, the SOC content, especially which in microaggregates was the key factor influencing the value of SOD. The results here could be useful for selection of the oxidant dosage and could also promote the efficiency oxidation remediation technology. [ABSTRACT FROM AUTHOR]

Natural soil and vegetation recovery following human disturbance is the primary means of restoring degraded ecosystems globally. However, it remains unclear how vegetation recovery in the tropical karst areas of China affects the soil physicochemical properties. Here, we investigated the impacts of natural vegetation recovery on soil physicochemical properties at different soil depths in tropical karst areas in southwestern China, using a space–time substitution method. We found that with the natural vegetation recovery, soil bulk density (SBD) decreased. Soil pH initially decreased and then increased, reaching its lowest value during the shrubland stage. There was a significant increase in other soil physicochemical factors. In the soil profiles, SBD tended to increase with depth. The pH, total potassium (TK), total phosphorus (TP), and exchangeable calcium remained relatively stable across the different soil layers. TK, TP, available phosphorus, SBD, total nitrogen, pH, exchangeable magnesium, and available potassium significantly contributed to the soil physicochemical properties. Soil physicochemical properties were predominantly directly affected by litter and biological factors, albeit indirectly influenced by topographic factors. Our study provides crucial insights into karst soils and their relationship with vegetation recovery, which are pivotal for steering vegetation restoration and soil amelioration in karst areas. [ABSTRACT FROM AUTHOR]

The cultivation of Cunninghamia lanceolata (Lamb.) Hook. (Chinese fir) plays a crucial role in enhancing ecological security through water resource preservation and carbon sequestration in China. The biotic and abiotic environmental conditions vary across different stages of plantation, thereby influencing soil nutrient levels and microbial dynamics. However, the interconnection between the soil nutrient cycle and microbial communities within Chinese fir plantations throughout their entire life cycle remains inadequately understood. In this study, conducted across various management stages of Chinese fir plantations in China (including the juvenile stage, first thinning stage, second thinning stage, mature stage, and over-mature stage), we examined the associations among soil organic carbon, soil physicochemical properties, soil enzyme activities, and soil microbial dynamics. Our results revealed that forest management practices significantly modify soil physicochemical properties and enzyme activities across all management stages. Specifically, the concentrations of total soil carbon, soil organic carbon, and soil microbial biomass carbon were notably higher in the over-mature stage compared to other management stages. At the genus level, the five highest contributors belonged to Subgroup2, AD3, Xanthobacteraceae, Elsterales, and Acidobacteriales for the bacterial community. For the fungal community at the genus level, the five highest contributors belonged to Ascomycota, Serendipita, Saitozyma, Mortieralla, and Venturiales. Moreover, anthropogenic thinning activities during the management phase substantially altered both stand and soil environments, as well as the structural characteristics of soil microbial communities. Soil cellulase, soil electrical conductivity (EC), and soil available phosphorus (AP) emerged as key factors influencing the relative abundance of major fungal communities, whereas soil total nitrogen, EC, and AP were identified as critical factors affecting the relative abundance of major bacterial phyla. More microbiological groups increased significantly in the juvenile stage and over-mature stage. Our findings elucidate the intricate relationships between the soil nutrient cycle and soil microbiological dynamics across various forest management stages within Chinese fir plantations. [ABSTRACT FROM AUTHOR]

In order to explore the changes and interrelationships of grassland plant community species diversity and soil physicochemical properties with elevation gradient, this study takes the grassland in the Burzin forest area of Xinjiang as the research object and analyzes the responses of grassland species diversity, aboveground biomass, and soil physicochemical properties to the changes of elevation gradient within the altitude range of 1000~2200 m in this area. The results of the study show that: (1) The number of species and aboveground biomass reached the highest levels at elevation gradient III and showed a tendency of increasing and then decreasing with elevation. The Margalef and Shannon–Wiener indices were the largest at elevation III, while the Simpson and Alatalo indices were the largest at elevation I. (2) With the change of elevation, the available nitrogen (AN), available phosphorus (AP), soil electric conductivity (SEC), and soil pH showed a trend of increasing and then decreasing, while soil temperature decreased with elevation. Available potassium and soil water content reached their maximum values at elevation I and elevation IV, respectively. (3) The soil conductivity and diversity index were negatively correlated in elevation gradients I to III. In elevation gradient I~III, soil conductivity was positively correlated with the diversity index and aboveground biomass. Available nitrogen had a significant effect on plant diversity and biomass in elevation gradients IV to VI. (4) Aboveground biomass was significantly positively correlated with the Simpson's index, while the relationship with the Shannon–Wiener index was less significant, and Margalef's and Alatalo's indices were not significant. Soil conductivity and pH significantly affected the Margalef and Simpson indices. Available nitrogen was closely related to the aboveground biomass and Margalef and Alatalo indices. Soil moisture content significantly affected Simpson's index and the aboveground biomass. This study provides a solid theoretical foundation for the conservation and management of grassland plant community ecosystems along the elevation gradient, and has important reference value for study of the impact of environmental change on species diversity and biodiversity conservation. [ABSTRACT FROM AUTHOR]

Introduction: Arbuscular mycorrhizal fungi (AMF) are vital in terrestrial ecosystems. However, the community structure characteristics and influencing factors of AMF in the forest ecosystems of arid desert grassland areas require further investigation. Methods: Therefore, we employed high-throughput sequencing technology to analyze the soil AMF community characteristics at different elevations in the Helan mountains. Results: The results revealed that significant differences (P < 0.05) were observed in the soil physicochemical properties among different elevations, and these properties exhibited distinct trends with increasing elevation. Through highthroughput sequencing, we identified 986 operational taxonomic units (OTUs) belonging to 1 phylum, 4 classes, 6 orders, 12 families, 14 genera, and 114 species. The dominant genus was Glomus. Furthermore, significant differences (P < 0.05) were observed in the a-diversity of the soil AMF community across different elevations. Person correlation analysis, redundancy analysis (RDA), and Monte Carlo tests demonstrated significant correlations between the diversity and abundance of AMF communities with soil organic matter (OM) (P < 0.01) and soil water content (WC) (P < 0.05). Discussion: This study provides insights into the structural characteristics of soil AMF communities at various altitudes on the eastern slope of Helan mountain and their relationships with soil physicochemical properties. The findings contribute to our understanding of the distribution pattern of soil AMF and its associations with environmental factors in the Helan mountains, as well as the stability of forest ecosystems in arid desert grassland areas. [ABSTRACT FROM AUTHOR]

[Objective] The aims of this study are to determine the appropriate stand density, and to provide the reference for implementing effective restoration practices for improving soil quality of Robinia pseudoacacia plantation in the hilly and gully region of the Loess Plateau in China by analyzing the response of soil physicochemical properties and enzyme activities to stand density changes and the relationship between soil physicochemical properties and enzyme activities. [Methods] R. pseudoacacia plantations of three stand density classes-low density (900 trees/hm²), medium density (1 200 trees/hm²), and high density (1 500 trees/hm²) density were sampled in the Xiannangou watershed of Ansai County in loess hilly-gully region of northern Shaanxi Province, China. We analyzed the effects of stand density on soil physicochemical properties, enzyme activities, and determined the relationship between soil physicochemical properties and enzyme activities by redundancy analysis. [Results] (1) Compared to low-and high-density plantations, medium density plantations significantly increased soil water content, soil organic carbon, soil total nitrogen, soil available phosphorus, and soil nitrate nitrogen. (2) With the increasing in stand density, the soil enzyme activities, including ẞ-glucosidase, cellulase, invertase, polyphenoloxidase, catalase. urease. leucine aminopeptidase, and N-acetyl-ẞ-glucosaminidase decreased first and then increased, and were the lowest at medium density plantations. (3) Pearson analysis showed that soil enzyme activities related to carbon, nitrogen, and phosphorus cycle negatively were correlated with the content of the corresponding resource. (4) Results of redundancy analysis showed that soil organic carbon, total nitrogen, and total phosphorus had significant effects on soil enzyme activities. Soil organic carbon, total nitrogen, and total phosphorus explained 59.8% (p<0.01), 20.8% (p<0.01), and 9.5% (p<0.05) of the variation of soil enzyme activities, respectively. [Conclusion] Medium density (1 200 trees/hm²) can help to conserve soil nutrient and water of R. pseudoacacia plantation, and thus is a suitable stand density management strategy for R. pseudoacacia plantations to improve soil quality. Furthermore, managers should pay attention to the changes in soil organic carbon content to implement stand density controlling to improve soil enzyme activity and hence enhance soil nutrient availability and promote the improvement of R. pseudoacacia plantations. [ABSTRACT FROM AUTHOR]

[Objective] The aims of this study are to explore the fractal characteristics of deep profile soil under different vegetation types and their relationship with soil physicochemical properties and hydraulic parameters, and to provide important reference basis for vegetation restoration and agricultural production. [Methods] Shenmu Liudaogou watershed in Shaanxi Province was taken as the research area. Soil samples with a depth of 13 meters were collected from four vegetation types (grassland, apricot, pine. and peashrub) in the area. Soil particle composition, moisture content, and organic carbon content were measured. Soil fractal dimension was calculate. The fractal characteristics of deep profile soil under different vegetation types analyzed. [Results] (1) The soil clay, silt, and sand contents in this area are about 15%, 40% and 45%, respectively, and the differences in soil particle composition under different vegetation were significant (p<0.05). (2) The fractal dimension of the four sample plots did not differ significantly (p>0.05) throughout the profile, and the effect of vegetation type on soil fractal dimension was significant (p<0.05) in the depth of 1~2 m. (3) The fractal dimension of the pine and grassland was greater than the other two sample plots. In addition, soil fractal dimension is significantly correlated with clay content and soil hydraulic parameters (0,, n and Ksat) (p<0.05), but not with soil organic carbon and soil moisture content (p>0.05). [Conclusion] Soil fractal dimension is mainly influenced by soil fine particles, and is indicative of soil hydraulic properties. Pine and grassland have the best effect on soil structure improvement. This study has important implications for the sustainable use and management of vegetation and water resources in dryland areas, [ABSTRACT FROM AUTHOR]

Copyright of Acta Prataculturae Sinica is the property of Acta Prataculturae Sinica Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

[Objective] This study aimed to explore the influence mechanism of rock strata dip on soil erodibility and provide references for preventing and controlling water and soil erosion in karst trough valley area. [Methods] The study focused on the dip/anti-dip slope of Qingmuguan karst trough valley area in Chongqing city. Through flume erosion experiments, we analyzed the differences in soil erodibility between different land use types on the dip/anti-dip slopes and investigated the impact of soil physicochemical properties on soil erodibility. [Results] (1) Both dip/anti-dip slopes showed a significant negative correlation with organic matter content, >0.25 mm water-stable aggregates content, and total nitrogen content (p0.25 mm water-stable aggregate content, and total nitrogen compared to the dip slope. (2) Soil erodibility was higher on the dip slope than on the anti-dip slope for all four land use types studied. Additionally, grassland had lower comprehensive scores of soil erodibility than pepper fields, cornfields, and bare land on both the dip/anti-dip slopes. (3) Based on stepwise multiple regression analysis results, prediction models for soil erodibility on the dip/anti-dip slopes were established using organic matter content and >0.25 mm water-stable aggregate content as predictors with determination coefficients R2 of 0.77 and 0.85 respectively. [Conclusion] In summary, grassland had the lowest soil erodibility among all land use types studied regardless of the dip/anti-dip slopes in karst trough valley. Therefore, in order to prevent soil erosion and promote ecological restoration in karst trough valley, it is necessary to cultivate the land reasonably and increase grassland coverage appropriately, thus enhancing the soil's resistance against erosion.

[Objective] Investigating the response mechanism of soil microbial communities to changes in grazing intensity can provide scientific theoretical and technical support for ecological protection and restoration of desert steppe. [Methods] Taking the desert steppe in Inner Mongolia as the research object, we studied the effects of different grazing intensities (no grazing, light grazing, medium grazing, and high grazing) on soil physicochemical properties and the composition and diversity of soil microbial communities at different soil depths (0—20 cm and 20—40 cm), the interactions between soil physicochemical properties and soil microbial communities were analyzed. [Results] Compared to no grazing, medium grazing significantly (p0.05) under different grazing intensities. In addition, grazing decreased the abundance and diversity of bacterial communities at 20—40 cm depth, while increased the abundance and diversity of bacteria communities at 20—40 cm depth. Under light and moderate grazing conditions, the abundance and diversity of soil fungal communities at 0—20 cm depth increased, with no significant effect (p>0.05) on the abundance and diversity of soil fungal communities at 20—40 cm depth. [Conclusion] Mantel tests showed that total nitrogen of desert steppe soil was the primary factor influencing the change of desert steppe soil bacterial abundance with grazing intensity. The research results contribute to understanding the ecological sensitivity of soil microbes and offer scientific guidance for achieving sustainable management in desert steppe ecosystems.

In order to provide theoretical basis for soil mulching standards, the effects of mulching wood chips on soil physicochemical properties and the growth and development of cherry blossom roots were investigated. The changes of soil physical and chemical properties and root growth of cherry blossoms after laying wood chips were measured. The results showed that mulching wood chips could significantly improve soil physicochemical properties and promote root growth of cherry blossoms. After mulching wood chips, the soil bulk density decreased significantly, while the soil mass water content, volumetric water content, water storage capacity, maximum water capacity, capillary water capacity, minimum water capacity, non-capillary porosity, capillary porosity and total porosity increased significantly. The pH value decreased significantly after covering wood chips, and the soil organic matter content, available phosphorus, available potassium, nitrate nitrogen, total iron and total zinc contents were significantly higher than those of soil without wood chip covering. Covering with wood chips could promote the growth of cherry blossom roots, and the total length of cherry blossom roots after covering with wood chips was more than 10 times that without covering. The correlation analysis results showed that the soil bulk density and non-capillary porosity were significantly correlated with the root growth of cherry blossom. The smaller the soil bulk density and the larger the non-capillary porosity were, the more favorable the root growth of cherry blossom. In summary, the soil covered with wood chips in cherry blossom garden could improve the physical and chemical properties of soil and promote the growth of cherry blossom roots. [ABSTRACT FROM AUTHOR]

Many species of Salvia have excellent ornamental, culinary, and medicinal values. Salvia daiguii, is an ornamental and highly medicinal perennial herb endemic to the prefecture‐level city of Zhangjiajie in Hunan Province, China, with a narrow geographical distribution. However, currently, it has only been assessed as a Critically Endangered species according to the IUCN classification criteria, but its conservation has not yet been studied. This study investigated the distribution and niche characteristics of S. daiguii, and compared the differences in growth, flowering characteristics, and soil nutrients between the wild and ex situ populations. We also analyzed the effects of soil nutrients on plant growth and flowering characteristics. During the survey, we found 274 individuals on a rock approximately 200 m from ZEFR1. Nevertheless, S. daiguii were still restricted in three populations, TNFP, TGM, and ZEFR in Zhangjiajie City, with a total of about 500 plants and less than 250 mature individuals. Our results show that aspects such as adverse environmental conditions, low seedling renewal rate, a lack of soil nutrients, and competition for the characteristic niche of this and other dominant plants in the natural community are the main ecological factors affecting the growth, flowering, and geographic distribution of S. daiguii. Based on the results of field surveys, we recommend that (1) S. daiguii be classified as Critically Endangered C2b and China's List of Plant Species with Extremely Small Populations. (2) Comprehensive conservation strategies were developed, such as the establishment of nature reserves, reintroduction, public education, and institutional development to provide management recommendations related to the conservation of S. daiguii and other endangered plants. [ABSTRACT FROM AUTHOR]

Karst hillslopes are generally characterized by different land uses. Land use and slope position impact soil erosion seriously, which in turn impacts the process of soil development and the patterns of soil properties. However, the impact of land use on soil physicochemical properties and the spatial variations and correlations between them are not fully understood on karst hillslopes. Therefore, nine sites had similar soil types, slope gradients, elevations, slope aspects and previous tillage practices were selected to conduct further research. This study was conducted to quantify the spatial distribution, variability and correlation of soil physical and chemical properties and stoichiometries as impacted by different land uses on a karst hillslope in Southwest China. Soil physical properties were significantly affected by slope position and soil depth. The soil bulk density and clay content increased with soil depth, while the opposite was true for the sand content. For the three land uses, the soil bulk density varied the most at the lower slope position, while clay and sand particles varied the most at the middle slope position. The mean spatial coefficient of variation (CV) of soil physical properties was ranked as sand (11.08%) > clay (7.77%) > bulk density (6.85%) > silt (3.81%). The mean spatial CV of soil chemical properties was ranked as available K (44.49%) > total P (16.77%) > total C (16.31%) > total N (13.09%) > available P (8.45%) > total K (7.51%). Overall, soil physicochemical properties exhibited significant spatial differences with slope location and land use on karst hillslopes. Soil chemical properties had greater spatial variation than physical properties, moreover, there were significant correlations between them. The results not only contribute to a deeper understanding of the impact of land use on the erosion process and mechanism on karst hillslopes but also provide a scientific understanding of the sustainable restoration of karst ecosystems. [ABSTRACT FROM AUTHOR]

This study investigated the effect of nitrogen application on the rhizosphere soil microenvironment of sunflower and clarified the relationship between ammonium assimilation and the microenvironment. In a field experiment high (HN, 190 kg/hm²), medium (MN, 120 kg/hm²) and low nitrogen (CK, 50 kg/hm²) treatments were made to replicate plots of sunflowers using drip irrigation. Metagenomic sequencing was used to analyze the community structure and functional genes involved in the ammonium assimilation pathway in rhizosphere soil. The findings indicated that glnA and gltB played a crucial role in the ammonium assimilation pathway in sunflower rhizosphere soil, with Actinobacteria and Proteobacteria being the primary contributors. Compared with CK treatment, the relative abundance of Actinobacteria increased by 15.57% under MN treatment, while the relative abundance decreased at flowering and maturation stages. Conversely, the relative abundance of Proteobacteria was 28.57 and 61.26% higher in the MN treatment during anthesis and maturation period, respectively, compared with the CK. Furthermore, during the bud stage and anthesis, the abundance of Actinobacteria, Proteobacteria, and their dominant species were influenced mainly by rhizosphere soil EC, ammonium nitrogen (NH+4-N), and nitrate nitrogen (NO- 3-N), whereas, at maturity, soil pH and NO-3-N played a more significant role in shaping the community of ammonium-assimilating microorganisms. The MN treatment increased the root length density, surface area density, and root volume density of sunflower at the bud, flowering, and maturity stages compared to the CK. Moreover, root exudates such as oxalate and malate were positively correlated with the dominant species of Actinobacteria and Proteobacteria during anthesis and the maturation period. Under drip irrigation, applying 120 kg/hm² of nitrogen to sunflowers effectively promoted the community structure of ammonium-assimilating microorganisms in rhizosphere soil and had a positive influence on the rhizosphere soil microenvironment and sunflower root growth. [ABSTRACT FROM AUTHOR]

Simple Summary: The dynamics of the soil bacterial communities in rotational shifting cultivation fields were investigated. A six-year interval of fallow years did not result in any differences in the soil bacterial communities. A recovery in the abundance of the soil bacterial communities was observed during the rainy season. An increase in bacterial richness occurred during the year after a burn. After one year, the diversity of the bacterial communities reverted to pre-burning levels. Fire is a common practice in rotational shifting cultivation (RSC), but little is known about the dynamics of bacterial populations and the impact of fire disturbance in northern Thailand. To fill the research gap, this study aims to investigate the dynamics of soil bacterial communities and examine how the soil's physicochemical properties influence the bacterial communities in RSC fields over a period of one year following a fire. Surface soil samples (0–2 cm depth) were collected from sites with 6 (RSC-6Y) and 12 (RSC-12Y) years of fallow in Chiang Mai Province, northern Thailand at six different time points: before burning, 5 min after burning (summer), 3 months after burning (rainy season), 6 months after burning (rainy season), 9 months after burning (winter), and 12 months after burning (summer). The results revealed a reduction in the soil bacterial communities' diversity and an increase in soil nutrient levels immediately after the fire. The fire significantly influenced the abundance of Firmicutes, Proteobacteria, Acidobacteria, and Planctomycetes, but not that of Actinobacteria. At the genus level, Bacillus, Conexibacter, and Chthoniobacter showed increased abundance following the fire. During the rainy season, a recovery in the abundance of the soil bacterial communities was observed, although soil nutrient availability declined. Soil physicochemical properties such as pH, organic matter, organic carbon, electrical conductivity, cation exchange capacity, nitrate-nitrogen, available phosphorus, exchangeable potassium, total nitrogen, bulk density, sand, and silt contents significantly influenced the composition of bacterial communities. Alpha diversity indices indicated a decrease in diversity immediately after burning, followed by an increase from the early rainy season until the summer season, indicating that seasonal variation affected the composition of the soil bacterial communities. After one year of burning, an increase in bacterial richness was observed, while the diversity of the bacterial communities reverted to pre-burning levels. [ABSTRACT FROM AUTHOR]

This study was carried out to evaluate the effects of the combined application of water-retaining agents and nitrogen fertilizers on soil physicochemical properties, bacterial communities, and root growth under winter wheat planting mode in the Guanzhong area of Shaanxi Province. Based on the positioning experiment of dry farming in the loessal soil area of Shaanxi Province, four treatments were set up by using the tillage method of subsoiling + rotary tillage and straw returning: only fertilization (U), only water retention agent sodium polyacrylate (C3H3NaO2)n (S), combined use of water-retaining agent sodium polyacrylate (C3H3NaO2)n and fertilizer (US), and control group CK (no treatment). The ultra-high-throughput sequencing of 16S rRNA genes of soil bacteria was performed by the Illumina Hiseq platform, and the effects of different tillage measures on soil bacterial diversity and community structure were analyzed. In addition, the effects of these tillage measures on soil physicochemical properties and winter wheat root length density at booting and flowering stages were evaluated. The results indicated that the combination of the water-retaining agent and fertilizer markedly enhanced the contents of ammonium nitrogen, available phosphorus, and available potassium in the 0~20 cm soil layer, significantly increased the soil moisture content, and promoted the deep growth of roots. The root length density was 4.70 times higher than that of the control group at the booting stage. In addition, the combined application alleviated the decrease in soil microbial diversity caused by individual fertilization, especially significantly increasing the abundance of Gemmatimonadetes, Acidobacteria, and Planctomycetes in the 0~10 cm soil layer. This study reveals the potential of the combined use of water retention agents and fertilizers to optimize the soil environment and enhance winter wheat yield, which provides a scientific basis for improving local agricultural practices. [ABSTRACT FROM AUTHOR]

Drought is expected to increase in temperate regions in the coming decades due to global climate change and will strongly affect nitrogen (N) transformation and balance. However, the underlying mechanisms (soil microenvironment vs. biotic community) of rainfall reduction induced changes in soil N transformation rates, and whether the responses of soil N transformation rates to rainfall reduction vary over time remains poorly understood. In this study, we experimentally examined rainfall reduction effects on soil N transformation rates over two (the second and third experimental years) growing‐seasons in a temperate meadow. We applied four treatments: ambient rainfall, 30%, 50%, and 70% reduction in rainfall. Our findings demonstrated that, 70% rainfall reduction significantly decreased the average net N mineralization and nitrification rates by 68.4% and 72.0%, respectively. Soil nitrous oxide emission was profoundly varied between the experimental years, with it was sensitive no only to changes in annual precipitation amount, but also to seasonal distribution, the highest emissions appeared at the early growing‐season. Moreover, plant diversity, microbial biomass, and soil NO3−‐N content mainly regulated soil N transformation rates in response to rainfall reduction in the greater annual precipitation year; but soil N transformation rates were mainly controlled by soil water content in the less annual precipitation year. We suggest that to accurately project future ecosystem functions and improving the prediction of N cycling responses to changing precipitation patterns, stronger focus should be allocated not only to changes in precipitation amounts, but also to inter‐ and intra‐annual differences in precipitation distribution. Plain Language Summary: The variation in precipitation regimes may have profound impacts on soil N cycling. To understand how the soil N transformation rates respond to different rainfall levels, we used rainout shelters to simulate reduced precipitation amount in a temperate meadow. We examined a suite of soil N transformations responses. Our results showed that soil N transformation rates decreased along the gradient of declining in rainfall amount over the two sampling years, with inter‐ and intra‐annual variation in precipitation distribution also played important roles in determining soil N transformation rates. The high values of each soil N transformation rates were appeared at different periods of the growing‐seasons. We also examined the pathways associated with the responses of soil N transformation rates to rainfall reduction in the two contrasting precipitation years. In summary, we conclude that rainfall reduction led to reductions in soil N transformation rates through a combination of plant, microbial, and soil factors during the greater annual precipitation. Nonetheless, in the less annual precipitation, the key factor determining N transformations was found to be soil water content. These findings offer valuable insights for forecasting interactions within the plant‐microbe‐soil N cycling system under forthcoming precipitation patterns within the context of climate change. Key Points: The high soil N transformation rates corresponded to a certain precipitation range at regional scaleRainfall reduction decreased soil N transformation rates via changing plant, microbial, and soil factors in greater precipitation yearSoil water content was the key factor determining soil N transformation rates, especially in less precipitation year [ABSTRACT FROM AUTHOR]

This paper aimed to investigate soil physicochemical properties and concentration of nutrients released by litter in assisted natural regeneration (ANR) Sal Forest and compared with non-ANR. Soils were collected at 0-15 cm and 16-30 cm depths across each site for three seasons, that is, summer, rainy, and winter. The soil at both the study sites was sandy loam. The results indicate the maximum values of soil physicochemical characteristics during the rainy season, i.e., soil moisture (25.04%), bulk density (1.5%), pH (7.24%), carbon (2.26%), nitrogen (0.096%), phosphorus (0.006%), and potassium (0.27%) followed by summer and minimum in the winter season. The values decline with increasing depths whereas pH and bulk density have shown a reverse trend. In both the sites, the nutrient content of litter was maximum in the rainy and minimum in the winter season in the following order: N > K > P. Hence, the findings unveil that ANR Sal Forest has rich physicochemical properties of soil as well as litter nutrients compared to non-ANR sites. The present study is the first comparative research made so far on soil physicochemical properties and litter nutrient dynamics in Sal ANR and non- ANR forests of Nainital, Kumaun Himalaya, and recommends that ANR practices are good for nutrient enrichment of soil and Sal growth and regeneration. [ABSTRACT FROM AUTHOR]

This study explores the complex relationship between soil electricity generating capacity, bacterial community dynamics, and soil chemical and physical properties across diverse regions of Japan. First, soil samples were systematically collected and analyzed. Subsequent investigations evaluated soil microbial biomass carbon, dissolved organic carbon (DOC), and total dissolvable iron (DFeT) concentrations. In the experiments, soil samples underwent a rigorous 60-day microbial fuel cell trial, wherein power density and total energy output were measured. Significant variations in power density were observed among different soil samples; specifically, a sugarcane field designated as Okinawa-3 and a peach orchard soil as Nagano-2 demonstrated relatively high total energy output. Analysis of soil bacterial community structures identified some families which showed positive correlations with increased electricity generation capabilities. Correlation analyses revealed associations between these bacterial communities and key soil parameters, particularly with DOC and DFeT concentrations. Redundancy analysis revealed intricate connections between soil properties and electricity generation capacities. Particularly noteworthy was the positive correlation between Acidobacteriaceae and DOC, as well that between Sphingomonadaceae and electricity generation, highlighting the crucial roles of soil microbial communities and chemical compositions in driving electricity generation processes. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Soil & Water Conservation (1009-2242) is the property of Institute of Soil & Water Conservation and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Soil & Water Conservation (1009-2242) is the property of Institute of Soil & Water Conservation and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The widespread adoption of large‐scale machines has led to a significant shift in terrace construction methods, transitioning from manual labor to mechanical processes. Mechanical terracing, by deeply disturbing the surface and compaction of the soil, has resulted in significant variations in both the soil physicochemical properties (SPCs) and soil infiltration properties (SIPs). However, few studies have been carried out to investigate the impact mechanisms of mechanical terracing on soils. In this study, we conducted detailed field experiments to determine the effects of mechanical terracing on SPCs and SIPs. The results showed that mechanical terracing increased soil compaction and decreased soil porosity and organic matter compared to manual terracing. Moreover, mechanical terracing had lower initial and steady infiltration rates than manual terracing (decreasing by 2.60% and 18.59%, respectively). However, initial and steady infiltration rates significantly improved compared to sloped land, increasing by 20.82% and 54.68%, respectively. The partial least squares path model indicated that bulk weight, organic matter content, and soil texture were the dominant influencing factors of SIPs. The results underscore the critical need to incorporate distinctions between various terrace construction methods into hydrological models for more accurate predictions. [ABSTRACT FROM AUTHOR]

Ageratina adenophora can enhance its invasive ability by using beneficial rhizosphere bacteria. Bacillus cereus is able to promote plant growth and provide a positive feedback effect to A. adenophora. However, the interaction between A. adenophora and B. cereus under the influence of native polyphagous insect feeding is still unclear. In this study, Eupatorium lindleyanum, a local species closely related to A. adenophora, was used as a control, aimed to compare the content of B. cereus in the roots of A. adenophora and rhizosphere soil after different densities of Aphis gossypii feeding, and then investigated the variations in the population of A. gossypii and soil characteristics after the addition of B. cereus. The result showed that B. cereus content in the rhizosphere soil and root of A. adenophora increased significantly under A. gossypii feeding compared with local plants, which also led to the change of a-diversity and b-diversity of the bacterial community, as well as the increase in nitrate nitrogen (NO3-N) content. The addition of B.cereus in the soil could also inhibit the population growth of A. gossypii on A. adenophora and increase the content of ammonium nitrogen (NH4+-N) in the soil. Our research demonstrated that B. cereus enhances the ability of A. adenophora to resist natural enemy by increasing soil ammonium nitrogen (NH4+-N) and accumulating other beneficial bacteria, which means that rhizosphere microorganisms help invasive plants defend themselves against local natural enemies by regulating the soil environment. [ABSTRACT FROM AUTHOR]

Microbial inoculants derived from plant growth-promoting rhizobacteria (PGPR) offer eco-friendly alternatives to traditional chemical fertilizers, maintaining microbiota balance in agricultural systems. However, limited research has explored the combined effects of microbial inoculants and chemical fertilizers on crop growth and soil properties. In this study, we investigated seven fertilizer combinations, ranging from no fertilizer to various proportions of chemical fertilizers with microbial inoculants, on timothy (Phleum pratense L.) growth, chlorophyll content, soil properties, enzyme activities, and soil microbial communities. A randomized block design was employed to analyze these effects. The results indicate that the combination of 85% chemical fertilizer with microbial inoculants significantly increased timothy yield and chlorophyll content. In addition, a reduction to 55% chemical fertilizer in conjunction with microbial inoculants resulted in comparable yield to that of 100% fertilizer with no inoculants. The microbial inoculants treatments notably elevated soil catalase, urease, acid phosphatase, and invertase activities, along with soil fast-acting nutrient content. The sequencing results show that the abundance of beneficial bacteria increased, while that of fungi decreased in the soil rhizosphere after the application of microbial inoculants. This study underscored the potential of microbial inoculants combined with reductions in chemical fertilizers to enhance soil microbiology, nutrient content, and beneficial microbial abundance while suppressing pathogenic fungi, thereby promoting timothy growth and yield. These findings provide a theoretical basis for the use of microbial inoculants in sustainable agricultural practices, providing valuable insights for optimizing microbial inoculants and chemical fertilizer formulations to mitigate the sustainability challenges posed by conventional fertilizers. [ABSTRACT FROM AUTHOR]

Cultivated grasslands are an important part of grassland ecosystems and have been proven to be major carbon sinks, then playing an important role in the global carbon balance. The effect of cultivated grassland type (Medicago sativa, Triticum aestivum, Secale cereale, and Vicia villosa grasslands) on carbon flux (including net ecosystem CO2 exchange (NEE), ecosystem respiration (ER), and gross ecosystem productivity (GEP)) downstream of the Yellow River was studied via the static chamber technique and a portable photosynthetic system. Bare land was used as a control. The results showed that the four cultivated grassland types were mainly carbon sinks, and bare land was a carbon source. The cultivated grassland types significantly affected carbon flux. The average NEE and GEP of the grassland types were in the following order from high to low: Medicago sativa, Secale cereale, Triticum aestivum, and Vicia villosa grassland. Stepwise regression analysis showed that among all measured environmental factors, soil pH, soil bulk density (BD), soil organic carbon (SOC), and soil microbial carbon (MBC) were the main factors affecting CO2 flux. The combined influence of soil BD, SOC, and pH accounted for 77.6% of the variations in NEE, while soil BD, SOC, and MBC collectively explained 79.8% of changes in ER and 72.9% of the changes in GEP. This finding indicates that Medicago sativa grassland is a cultivated grassland with a high carbon sink level. The changes in carbon flux were dominated by the effects of soil physicochemical properties. [ABSTRACT FROM AUTHOR]

Coal mining is crucial to satisfying energy demands. However, mining activities create structural and functional changes and release potentially toxic elements (PTEs). Interaction between PTEs and soil physicochemical properties is bidirectional. Therefore, modelling interactions and predicting PTEs is critical for mitigating the consequences of mining activities on soil. The current study is being conducted in Jharkhand state, India, in active mining, abandoned mining, and non-mining locations, to determine soil physicochemical and metallic characteristics. Statistical analysis, including chemometric analysis and multiple linear regression (MLR), was used to investigate the impacts of bidirectional interactions of soil parameters on PTEs. Metals such as Co, Cr, Pb, and Ti have been identified as PTEs. Chemometric study found that PTEs in mining sites are the result of mining activities, but PTEs in non-mining and abandoned mine sites are geological in origin. During the active mining period, mining alters the soil profile and raises PTE concentrations above critical thresholds. The MLR models applied to PTEs of non-mining and active mining sites had R2 values ranging from 88.80% to 99.97%, indicating that a well-defined soil profile allows us to forecast PTEs with high accuracy. In non-mining areas, the PTE concentration is substantially within the critical limits. However, coal mining alters the soil profile and releases PTEs into the earth by breaking down the soil metal complex. The loosened soil contains PTEs in the form of ions or water-dissolved particles. The disturbed soil profile of an abandoned mine makes PTE prediction difficult (R2 prediction as low as 23.43%). Leaching, runoff water, evaporative loss, and phytoremediation processes all help to wash PTEs out of soil over time. Once the soil begins to consolidate into a stable soil profile, the necessary metals, which are more reactive than PTEs, dissociate and bind to the soil complexes restoring the soil health. [ABSTRACT FROM AUTHOR]

The consequences of coal mining on soil ecosystems are becoming more apparent and worrisome, as these areas are prone to contamination of heavy metal(loid)s. The 16S rRNA gene-based metagenomics analysis was used to investigate the structural and functional variation of the soil bacterial community in coal mine spoils from 4-, 12-, and 15-year-old sites. The variation in soil properties in reference to undisturbed forest soil and the ecological risk analysis of heavy metal(loid)s were also determined. The results suggested that the 12- and 15-year-old coal mine spoils were under ecological risk, as indicated by Hakanson's Risk assessment index. Accordingly, the structure of the bacterial community in the spoil soils were also differentially altered. It was also evident that soil physicochemical parameters and concentration of heavy metal(loid)s have influenced the structure of the bacterial community. The bacteria that predominated in mine spoils under ecological risk were Firmicutes, Actinobacteria, and Archaea. The predicted functional analysis suggests that the coal mine spoils from 12- and 15-year-old site contain abundant genes involved in genetic information processing and metabolism that might have assisted them in tolerating heavy metal(loid)s toxicity and surviving there. The co-occurrence pattern indicated association between the diverse metabolic pathways. Overall, we found changes in the key taxa of bacterial communities and the soil physicochemical properties of different-aged coal mine spoils and unpolluted forest soil. These findings suggest that soil bacterial communities could be used as bioindicators to monitor the condition of coal mining sites, which further helps in designing an appropriate strategy to restore those areas. [ABSTRACT FROM AUTHOR]

Using Chongming green eggplant material as the research object,different amounts of soil remediation bacterial agents were applied externally on the basis of conventional fertilization. The soil physicochemical properties, as well as indicators related to eggplant yield and quality, were tested, and the application effect was verified. The results showed that the soil remediation bacterial agent treatment increased eggplant yield, increased its commercial fruit rate and eggplant fruit quality, and improved various physical and chemical indicators of the soil, which had a good remediation effect on the soil. Based on the comprehensive yield and quality of eggplants, 2 250 kg/hm² of soil remediation bacterial agent was selected as the optimal dosage for improvement. [ABSTRACT FROM AUTHOR]

The study on the effects of polypeptide fertilizers(organic fertilizers converted from protein wastes) on the improvement of tobacco-growing soil and the growth and development of flue-cured tobacco aims to provide data support for ameliorating acidified soil, increasing the diversity of soil micro-ecological populations, and enhancing the yield and quality of tobacco leaves. In this study, using Yunyan 87 as the test material, three treatments of polypeptide fertilizers(H1, H2, H3) were set up, and tobacco-specific fertilizer(chemical fertilizer) was taken as the control, the soil's physicochemical properties, soil microbial communities, growth status of flue-cured tobacco, and the quality of flue-cured tobacco under different polypeptide fertilizer treatment conditions were identified. The results showed that compared to the application of conventional tobaccospecific fertilizers, the application of polypeptide fertilizers increased the soil pH value by 0.4. Additionally, the total calcium and exchangeable calcium content in the soil increased by 10.28% and 33.33%, respectively, while the total phosphorus and available phosphorus content decreased by 25.81% and 45.14%, respectively. This indicated that the application of polypeptide fertilizers could not only reduce the amount of phosphorus fertilizer used but also alter the soil's physicochemical properties. Soil microbial community analysis revealed that the addition of polypeptide fertilizers significantly enhanced the richness and diversity of the soil microbial communities in tobacco-growing soil, with an increase in the relative abundance of Gemmatimonas. The application of polypeptide fertilizers also improved the growth, yield, and quality of tobacco. In the treatment group with a 67% of reduction of phosphorus fertilizer, the plant height increased by 10 cm, and the content of organic acids in the tobacco leaves increased by 11.25%. Additionally, upper medium tobacco rate of cured tobacco leaves increased by 0.17% compared to the control. [ABSTRACT FROM AUTHOR]

Exploring the effects of environmental factors and plant physiological processes on plant nutrient stoichiometry is of great significance to understanding how wetland vegetation distributes and maintains function. However, we have a limited understanding of how the combination of plant communities and seasonality with soil physicochemical properties affects nutrient stoichiometry in wetland plants. In this study, we examined these factors in Carex thunbergii and soil across four types of plant communities dominant in the riparian zone of Shengjin Lake during the non−flooding periods of December 2020 and March 2021. In winter, the total foliar C, N, and P concentrations decreased along with an increase in plant coverage, which did not differ in spring. The C, N, C: P, and N: P of foliage significantly increased over the season, while soil C, N, C: P, and N: P significantly decreased over the season. Both in winter and spring, soil C and soil N decreased along with the increase of plant coverage. Our results suggest that both plant community and soil physicochemical properties have a significant influence on plant nutrient stoichiometry. This study improves our understanding of the seasonal dynamics of plant nutrients under different communities and soil physicochemical properties. [ABSTRACT FROM AUTHOR]

Background: Agricultural practice is considered as main factor affecting land degradation in several regions in Vietnam. However, there are limited studies relating to degraded soil properties and their soil fertility. This paper aimed to evaluate the degradation of agricultural soil under different land management practices. Methods: A total of 80 samples at 0-10 cm of agricultural soil were collected to analyze selected physicochemical properties. The group of degradation soil properties was classified based on their soil fertility using principal component analysis. Result: The results showed that physicochemical properties in agricultural soil along coastal regions were relatively lower than in hilly regions/secondary forests. High ratio of C:N in agricultural soil was because of degradation. The organic matter, nitrogen and phosphorous contents were low in the soil in lowland areas indicating a high level of degradation (1.43%, 0.09% and 0,04%, respectively). The samples classified into four groups (G1, G2, G3, G4) using principal component analysis indicated differences in soil properties due to degradation. Insufficient and excessive application of inorganic fertilizer could be a further reason affecting the status of soil properties. Overall, soil physicochemical properties indicated poor conditions for agriculture systems, thereby, careful soil management is the primary solution. [ABSTRACT FROM AUTHOR]

Rubber plantations have increased significantly under unprecedented economic growth in tropical areas, which leads to soil degradation and thereby alters soil hydrological processes. However, our understanding of how forest conversion affects soil hydrological processes remains unclear. Here, we collected soil samples from secondary forests (SF) and rubber plantations (RP) to determine the soil hydrological characteristics. We found the topsoil (0–20 cm) water retention in SF was higher than that of RP but displayed the contrast pattern in a deeper soil layer (20–60 cm). Meanwhile, the soil infiltration rates among the two vegetation types decreased significantly with infiltration time, with higher stable soil infiltration rates in SF than those in RP. Moreover, soil properties were also impacted by the forest conversion, such as the topsoil capillary porosity (CP) and total porosity (TP) in SF were higher than those of RP but contrasted in a deep soil layer. In comparison, the topsoil bulk density (BD) in SF was lower than that of RP, but contrasted in the deep soil layer and reached a significant level in the 0–10 and 40–50 cm (P  < 0.05). Overall, the soil water retention was mainly determined by the CP, which could explain 31.56% of the total variance in soil water retention, followed by TP (26.57%) and soil BD (26.47%), whereas soil texture exerts a weak effect on soil water retention. Therefore, we can conclude that the conversion of tropical rainforest into rubber plantations may accelerate soil erosion owing to its lower topsoil water retention and soil infiltration rates. [ABSTRACT FROM AUTHOR]

The drinking-water treatment sludge (DWTS) possesses intricate characteristics, which restrict its broad applicability. To tackle this issue, we employed DWTS obtained from the Minhang District of Shanghai as the primary constituent, blending it with a low-alkaline curing material to produce pelletized mulch. This investigation primarily focuses on evaluating the environmental safety of sludge pellet mulch (SPM) and scrutinizing alterations in soil physicochemical properties at various mulch thicknesses. The outcomes affirm the durability of SPM and the compliance of eight heavy metals with prescribed standards concerning their concentration, pH, and EC values. After applying SPM, noteworthy enhancements were observed in soil moisture, organic matter content, available nutrients, and the activity of four enzymes. Furthermore, a reduction in soil temperature was observed. For urban landscape mulching, SPM within the range of 9.6-28.8 kg/m² emerged as the preferred choice, yielding the most favorable overall soil quality improvements. [ABSTRACT FROM AUTHOR]

Agricultural plastic film, as an important agricultural production material in the China Hexi Corridor oasis agricultural area, is widely used in the intensive production process of purple garlic, which plays an important role in increasing yield, improving quality, ensuring supply, etc. However, the difference in decomposition characteristics between ordinary plastic film and degradable plastic film may affect soil moisture and temperature, thereby affecting soil biochemical properties. Therefore, we conducted a study to solve this problem. Specifically, in the Minle area of the Hexi Corridor, we selected 10 moisture-maintaining measures of ordinary transparent plastic film, transparent oxo-biodegradable plastic film (50-, 80-, and 110-day induction period), ordinary black plastic film, black oxo-biodegradable plastic film (50-, 80-, and 110-day induction period), wheat straw, and aubergine-super absorbent polymers and used the traditional open field without super absorbent polymers as a control. To analyze the effects of different moisture-maintaining measures on soil quality, garlic yield and quality, and water-fertilizer productivity in purple garlic farmland, and conduct a comprehensive evaluation of moisture-maintaining measures using principal component analysis. The results showed that all the moisture-maintaining measures could increase garlic yield, improve bulb quality and water–fertilizer productivity, improve the soil hydrothermal conditions, maintain soil fertility, increase the microbial quantity, and improve enzyme activity. Overall, transparent plastic film mulching was superior to black plastic film mulching, straw mulching, and A-SAP, with 110-day transparent oxo-biodegradable plastic film mulching being the most effective, and was not significantly different from the ordinary transparent plastic film. Compared with other moisture-maintaining measures, the yield, water productivity, irrigation water productivity, and nitrogen fertilizer partial factor productivity of purple garlic were significantly increased by 13.33% to 119.77%, 13.81% to 126.77%, 13.41% to 119.95%, and 13.33% to 119.76%, respectively. Meanwhile, the contents of allicin, soluble sugar, soluble protein, crude fiber, and amino acid content were increased by 1.44% to 14.66%, 4.64% to 36.46%, 0.38% to 28.27%, 1.89% to 26.29%, and 0.38% to 3.74%, and, due to the prolongation of oxo-biodegradable plastic film induction period, the soil microbial community changes from “fungi type” to “bacterium type,” reducing the occurrence of soil diseases and improving soil quality. On the basis of the Technique for Order Preference by Similarity to an Ideal Solution (TOPSIS) method, the soil quality was evaluated, and the yield, quality, and water productivity of garlic were comprehensively evaluated under each moisture-maintaining measure using principal component analysis. It was determined that the best soil quality and better bulb quality as well as higher garlic yield and water productivity were obtained when using the 110-day induction period transparent oxo-biodegradable plastic film. It can be used as a more reasonable moisture-maintaining measure and technical reference for the purple garlic industry in the China Hexi Corridor oasis agricultural area, which can ensure the improvement of quality and stabilization of yield and also solve the risk of environmental pollution caused by plastic film mulching at the source.

Soil is the material basis of ginseng survival, and revealing the correlation between soil and ginsenoside has far-reaching significance for the sustainable development of ginseng industry. In this study, the content of ginsenosides in 3-year-old ginseng roots, the physicochemical properties of rhizosphere soil and the microbial community composition were studied. The results showed that the contents of total saponins in different months were significantly different. The richness and diversity of soil microbial community decreased with the extension of planting time. The activities of complexed iron, organic matter and protease in soil had significant effects on α-diversity of soil microbial community. Functional gene analysis showed that carbon sequestration, protein translation, nitrogen metabolism, transcription factors and chlorophyll metabolism were the main functions of soil bacterial community. The results of correlation analysis and redundancy analysis showed that pH, available potassium, organic matter, complexed iron, Firmicutes and Acidobacteria were the key factors affecting ginsenoside accumulation. The changes of soil physical and chemical properties affect the abundance of soil microorganism, and the accumulation of ginsenoside in ginseng is affected by soil microorganism. A co-regulatory network of Physicochemical Properties-Microbe-Ginsenoside was established. To provide theoretical support for the cultivation of ginseng.

Studies on the effects of wildfires on soil are common in mixed-conifer forests worldwide; however, such studies are less frequent in the context of high-altitude mixed-conifer forests. In this research, we analyzed the soil physicochemical properties 14 years after a high-intensity wildfire. Soil samples were collected from a depth of 0–10 cm across 100 composite samples, representing both control and burnt areas. Our findings revealed significant changes in soil characteristics in the burnt area compared to the control area. Specifically, the average soil pH, electrical conductivity, and available potassium increased by 3 %, 81 %, and 53 %, respectively, in the burnt area, while available phosphorus decreased by 6 %. Conversely, the average total nitrogen and organic matter showed non-significant decreases of 20 % and 12 % in the burnt area compared to the control area. No significant differences were found in slope aspects. Electrical conductivity and available potassium varied significantly among upper (3300–3500 m), middle (3100–3300 m), and lower (2900–3100 m) altitude ranges. Principal component analysis explained a total of 50.1 % of the variance, with approximately 27.4 % explained by the first axis and 22.7 % by the second axis. The control and burnt areas were closely clustered, indicating similar soil properties. Electrical conductivity, available potassium, and pH were more linked to the burnt forests, while nitrogen and organic matter were more associated with the control forests. Consequently, post-fire restoration efforts should consider potential changes in soil nutrient availability to facilitate successful vegetation recovery. This study enhances the formulation of more precise post-fire land management strategies, improves forest restoration initiatives, and promotes sustainable land-use practices by comparing unburnt natural forests.

Soil quality is a globally important issue from the point of view of food production, maintenance of appropriate environmental quality and ecological balance. Assessing its quality and fertility using indices is one of the methods that make it possible to formulate recommendations for good soil management. The aim of the study was, therefore, to determine the spatial and temporal distribution of soil properties in the context of soil quality assessment (SQI) and soil fertility assessment (SFI, SEF, NIV, and SSFI) using the example of a Central European country (Poland). The inverse distance-weighted spatial interpolation technique was used to estimate the spatial distribution of soil quality and fertility indicators. So far, no research has been carried out that would include a comprehensive analysis of soil fertility and quality indicators in such a large research area over many years. The results of 216 points of monitoring the chemistry of arable soils in Poland from the period 1995–2020 for 28 physicochemical soil parameters were considered. The analyses carried out showed significant variability in the properties of the described soils in Poland, as evidenced by the principal component analysis (PCA) and the coefficient of variation (exceptions: bulk density, pH). It was found that heavy metals (Zn, Cd, Cu) were responsible for the deterioration of soil properties. The results obtained for different indices were different (SFI – most soils with good fertility, SEF – high fertility, NIV – soils highly enriched with nutrients, SQI – average soil quality). It was found that the SSFI is the most appropriate indicator among the analyzed indicators for Polish conditions in relation to arable soils, as it is adapted and calibrated to the specifics of this area. The Spearman correlation matrix showed that the largest group of statistically highly significant parameter pairs belonged to heavy metals (Ni/Zn, Zn/Pb, Zn/Cu, Ni/Cu). In contrast, the strongest correlations were recorded for Ni (with effective cation exchange capacity (ECEC), Mn, Mgav, Zn, Cu). The assessment revealed limiting factors and temporal trends in the overall evaluation of the quality of the country’s agricultural soils, which are important from the point of view of both sustainable development and agricultural production.

The invasive species Spartina alterniflora has significantly disrupted the ecological stability of coastal wetland ecosystems. Consequently, its control has become an important aspect of coastal wetland conservation. When controlling S. alterniflora, it is imperative to assess the ecological impacts of control methods. In this study, the effects of different control methods, i.e. “mowing + flooding” (MF) and “mowing + plowing” (MP), on the soil carbon and nitrogen contents in coastal wetlands were investigated in the Yellow River Delta, China. The results showed that the contents of soil organic carbon, inorganic carbon, and total nitrogen in the MF area within 2 years after treatment were 2.03–3.93 g/kg, 13.74–16.06 g/kg, and 0.24–0.47 g/kg, respectively, which were 36.33 %–-199 %, 2.91 %–36.71 % and 115.42 %–212.09 % higher than that those in the CK area, respectively. The C/N ratio in the MF treatment was 6.98–8.54, which was 5.42 %–40.30 % lower than that in the CK treatment. The contents of soil organic carbon, inorganic carbon, and total nitrogen in the MP area were 1.52–2.3 g/kg, 13.07–14.94 g/kg, and 0.2–0.32 g/kg, respectively, which were 15.91 %–54.18 %, 0.97 %–15.56 % and 35.19 %–182.26 % higher than those in the CK area. The C/N ratio in the MP area was 14.72 %–46.79 % lower than that in the CK area. Correlation analysis revealed that the soil carbon and nitrogen contents in the MF area were significantly positively correlated with the soil water content and electrical conductivity, and the C/N ratio was significantly negatively correlated with the soil sand content. In the MP area, the soil carbon and nitrogen contents were affected by the soil water content and electrical conductivity. The soil organic carbon content was also significantly negatively correlated with soil pH and significantly positively correlated with soil clay content. The C/N ratio was significantly negatively correlated with the total nitrogen content. Overall, the effects of MF on the soil carbon and nitrogen content in coastal wetlands were greater than those of MP. Future studies need to pay attention to the changes in tidal hydrological processes to more accurately assess the impacts of the control of S. alterniflora on the overall carbon sink capacity of the intertidal zone.

Abstract Purpose The health of rhizosphere soil microorganisms is an important indicator to evaluate soil quality. Therefore, understanding the response of rhizosphere soil microorganisms to tobacco crop succession is crucial for promoting the sustainable development of agriculture. Methods The microbial diversity and community structure of rhizosphere soil in continuous cropping and non-cropped tobacco for 7 years were analyzed by the Illumina platform. Result (1) Continuous cropping tobacco cause rhizosphere soil acidification and reduction in alkaline nitrogen (AN) and soil organic matter (SOM). (2) Continuous cropping tobacco reduces the diversity of rhizosphere soil microbial communities, increasing harmful functional microorganisms and declining beneficial ones. (3) The abundance of bacteria that perform nitrification and saprophytic fungi in the rhizosphere soil of continuous cropping areas decreases, inhibiting carbon and nitrogen cycling processes. (4) The composition and diversity of the soil rhizosphere microbial community are affected by the imbalance in the physicochemical property of the rhizosphere. Conclusion Continuous cropping tobacco cause rhizosphere soil acidification and nutrient imbalance, and the carbon and nitrogen cycles involved in microorganisms were damaged. Furthermore, the decreased diversity of rhizosphere soil microorganisms and the increased abundance of pathogenic fungi contribute to the continuous cropping obstacles of tobacco.

The use of local native plant species for ecological restoration and rehabilitation is considered an important strategy for nature-based solutions. To achieve this goal, the key work is to understand the distribution of local native plants and their limiting factors. Pittosporum tobira is a keystone species of the vegetation community in subtropical coastal areas, and it plays an essential role in the function and stability of the coastal vegetation buffer zone. The aim of this study was to identify the factors that restrict the growth of P. tobira in the subtropical supratidal zone. We investigated the growth and development of P. tobira plants at three field sites, Dongtou Island (DT), Yuhuan Island (YH), and Cangnan County (CN), in Zhejiang Province, China. To investigate the key factors restricting the growth of this species, we sampled soils from both the supratidal zone and the P. tobira habitat zone. Soils in the supratidal zone showed typical characteristics of sodium chloride-type saline-alkali soil, and the soluble salts content showed wide fluctuations. Some soils in the supratidal zone showed severe salinization. The soil pH and soluble salts contents were higher, but soil organic matter content was lower, in the supratidal zone than in the P. tobira habitat zone. Among the three wild P. tobira habitat sites, DT had the lowest soil nutrient contents. In soil from the DT site, the soluble salts content was 150 % higher and soil organic matter content was 50 % lower than those in soils from the YH and CN sites. Compared with P. tobira growing at the CN and YH sites, those growing at the DT site showed higher antioxidant enzyme activity, higher organic osmotic regulatory substances content, and lower malondialdehyde content in the leaves and roots. These results suggest that the growth and distribution of P. tobira are affected by the organic matter content, pH, and soluble salts content in soil. Among the three P. tobira populations studied here, the population at DT was the most tolerant to the highly saline conditions in this subtropical coastal area, and has potential applications in landscape restoration of the supratidal zone.