Soil Functions Research Articles

Assessment of carbon sequestration potential of mining areas under ecological restoration in China

Mining activities aggravate the ecological degradation and emission of greenhouse gases throughout the world, thereby affecting the global climate and posing a serious threat to the ecological safety. Vegetation restoration is considered to be an effective and sustainable strategy to improve the post-mining soil quality and functions. However, we still have a limited knowledge of the impact of vegetation restoration on carbon sequestration potential in mining areas. In this pursuit, the present study was envisaged to integrate the findings from studies on soil organic carbon (SOC) sequestration in mining areas under vegetation restoration with field monitoring data. The carbon sequestration potential under vegetation restoration in China's mining areas was estimated by using a machine learning model. The results showed that (1) Vegetation restoration exhibited a consistently positive impact on the changes in the SOC reserves. The carbon sequestration potential was the highest in mixed forests, followed by broad-leaved forests, coniferous forests, grassland, shrubland, and farmland; (2) The number of years of vegetation restoration and mean annual precipitation were found to be the important moderating variables affecting the SOC reserves in reclaimed soils in mining areas; (3) There were significant differences in the SOC sequestration potential under different vegetation restoration scenarios in mining areas in China. The SOC sequestration potential reached up to 9.86 million t C a−1, when the soil was restored to the initial state. Based on the meta-analysis, the maximal attainable SOC sequestration potential was found to be 4.26 million t C a−1. The SOC sequestration potential reached the highest level of 12.86 million t C a−1, when the optimal vegetation type in a given climate was restored. The results indicated the importance of vegetation restoration for improving the soil sequestration potential in mining areas. The time lag in carbon sequestration potential for different vegetation types in mining areas was also revealed. Our findings can assist the development of ecological restoration regimens in mining areas to mitigate the global climate change.

Effects and regulation Mechanisms of Phosphorus Fertilizer on Soil Carbon Cycle

This paper reviews the effects and regulation mechanisms of phosphorus fertilizer on soil carbon cycle, which is an important process for soil fertility, productivity, and climate change and introduces the background, significance, main pathways, mechanisms, influencing factors, research progress and challenges. The paper shows that phosphorus fertilizer can affect soil carbon cycle through various pathways, such as affecting plant productivity and carbon allocation, soil organic matter decomposition and mineralization, soil microbial community and function, and soil aggregate formation and stability. The paper also shows that the effects of phosphorus fertilizer on soil carbon cycle are influenced by many factors, such as the type, amount, application method and time of phosphorus fertilizer, and the soil type, climate condition, vegetation type and management measures. The paper concludes that the effects of phosphorus fertilizer on soil carbon cycle are both positive and negative, direct and indirect, short-term and long-term, local and global, forming a complex impact network. The paper suggests that more research is needed to clarify the mechanisms, interactions and feedbacks of the effects of phosphorus fertilizer on soil carbon cycle, and to develop effective models and indicators to evaluate and predict the effects of phosphorus fertilizer on soil carbon cycle. The paper also suggests that rational application of phosphorus fertilizer and scientific management of soil carbon cycle are important for improving crop phosphorus use efficiency, reducing excessive application of phosphorus fertilizer, protecting water resources and soil quality, and mitigating climate change.

Defensive alteration of root exudate composition by grafting Prunus sp. onto resistant rootstock contributes to reducing crown gall disease.

Grafting is a traditional and significant strategy to suppress soil-borne diseases, such as the crown gall disease caused by tumorigenic Agrobacterium and Rhizobium. Root exudates and the rhizosphere microbiome play critical roles in controlling crown gall disease, but their roles in suppressing crown gall disease in grafted plants remain unclear. Here, disease-susceptible cherry rootstock 'Gisela 6' and disease-resistant cherry rootstock 'Haiying 1' were grafted onto each other or self-grafted. The effect of their root exudates on the soil microbiome composition and the abundance of pathogenic Agrobacterium were studied. Grafting onto the disease-resistant rootstock helped to reduce the abundance of pathogenic Agrobacterium, accompanied by altering root exudation, enriching potential beneficial bacteria, and changing soil function. Then, the composition of the root exudates from grafted plants was analyzed and the potential compounds responsible for decreasing pathogenic Agrobacterium abundance were identified. Based on quantitative measurement of the concentrations of the compounds and testing the impacts of supplied pure chemicals on abundance and chemotaxis of pathogenic Agrobacterium and potential beneficial bacteria, the decreased valine in root exudates of the plant grafted onto resistant rootstock was found to contribute to decreasing Agrobacterium abundance, enriching some potential beneficial bacteria and suppressing crown gall disease. This study provides insights into the mechanism whereby grafted plants suppress soil-borne disease.

Biotransformation of roxarsone by earthworms and subsequent risk of soil arsenic release: The role of gut bacteria

The organoarsenical feed additive roxarsone (ROX) is a ubiquitous threat due to the unpredictable levels of arsenic (As) released by soil bacteria. The earthworms representing soil fauna communities provide hotspots for As biotransformation genes (ABGs). Nonetheless, the role of gut bacteria in this regard is unclear. In this study, the changes in As speciation, bacterial ABGs, and communities were analyzed in a ROX-contaminated soil (50 mg/kg As in ROX form) containing the earthworm Eisenia feotida. (RE vs. R treatment). After 56 d, earthworms reduced the levels of both ROX and total As by 59 % and 17 %, respectively. The available As content was 10 % lower in the RE than in R treatment. Under ROX stress, the total ABG abundance was upregulated in both earthworm gut and soil, with synergistic effects observed following RE treatment. Besides, the enrichment of arsM and arsB genes in earthworm gut suggested that gut bacteria may facilitate As removal by enhancing As methylation and transport function in soil. However, the bacteria carrying ABGs were not associated with the ABG abundance in earthworm gut indicating the unique strategies of earthworm gut bacteria compared with soil bacteria due to different microenvironments. Based on a well-fit structural equation model (P = 0.120), we concluded that gut bacteria indirectly contribute to ROX transformation and As detoxification by modifying soil ABGs. The positive findings of earthworm-induced ROX transformation shed light on the role of As biomonitoring and bioremediation in organoarsenical-contaminated environments.

Biochar amendments improve soil functionalities, microbial community and reduce Pokkah boeng disease of sugarcane

BackgroundBiochar is mainly used to enhance soil fertility, microbial activity, improve plant performance and reduce disease incidence.MethodsA greenhouse experiment was designed to investigate the response of biochar on rhizosphere soil chemical properties, enzyme activity, microbial communities, and sugarcane Pokkah boeng disease (PB). Two sugarcane varieties Zhongzhe 9 (Z9) and ROC22, susceptible/resistant to PB, were cultivated and treated with: no biochar, 15 t ha−1 biochar, and 30 t ha−1 biochar.ResultsThe amendment of 30 t ha−1 of biochar (B2) significantly improve soil pH by 1.50% and 9.61% compared with that of B1 and B0, followed by 0.51% increase by 15 t ha−1 of biochar (B1) compared with that of control (B0). The application of 15 t ha−1 biochar significantly increased available phosphorus (AP) and ammonium nitrogen (NH4+–N) by 209.93 mg kg−1 and 12.1 mg kg−1, while the application of 30 t ha−1 of biochar significantly increased 241.04 mg kg−1 of available potassium (AK) (P < 0.05). Furthermore, biochar application increased the activities of soil acid phosphatase (S-ACP), urease (S-UE), and sucrase (S-SC). Alpha diversity analysis showed that the addition of biochar significantly altered the variety and abundance of rhizosphere microorganisms (P < 0.01) and increased the relative abundance of beneficial microorganisms Rhodanobacteraceae, Stachybotryaceae, Agaricacea, Talaromyces, Nectriaceae, Sistotrema, and Bacillus (P < 0.01). There was a significant decrease in the relative abundance of the soil pathogen Fusarium (P < 0.01).ConclusionThese findings suggested that the application of 15 t ha−1 biochar could bring desirable variations in soil functionalities, modulate soil microbial community by increasing soil health and reduce the disease index of PB.Graphical

More than a meat- or synthetic nitrogen fertiliser-substitute: a review of legume phytochemicals as drivers of 'One Health' via their influence on the functional diversity of soil- and gut-microbes.

Legumes are essential to healthy agroecosystems, with a rich phytochemical content that impacts overall human and animal well-being and environmental sustainability. While these phytochemicals can have both positive and negative effects, legumes have traditionally been bred to produce genotypes with lower levels of certain plant phytochemicals, specifically those commonly termed as 'antifeedants' including phenolic compounds, saponins, alkaloids, tannins, and raffinose family oligosaccharides (RFOs). However, when incorporated into a balanced diet, such legume phytochemicals can offer health benefits for both humans and animals. They can positively influence the human gut microbiome by promoting the growth of beneficial bacteria, contributing to gut health, and demonstrating anti-inflammatory and antioxidant properties. Beyond their nutritional value, legume phytochemicals also play a vital role in soil health. The phytochemical containing residues from their shoots and roots usually remain in-field to positively affect soil nutrient status and microbiome diversity, so enhancing soil functions and benefiting performance and yield of following crops. This review explores the role of legume phytochemicals from a 'one health' perspective, examining their on soil- and gut-microbial ecology, bridging the gap between human nutrition and agroecological science.

Integrated use of organic and synthetic fertilizers improves soil functioning, growth, yield and quality attributes of maize

The combined use of organic and chemical fertilizers may prove to be an excellent option for maintaining soil health, increasing fertilizer use efficiency, and improving crop quality and yield of maize. So, with this objective in mind a pot experiment was conducted to find out the effectiveness of organic and synthetic fertilizers on the yield and quality of maize crop. Two organic fertilizer levels (FYM and Press-mud @ 2% and 4% of each) were tested separately and in combination with recommended NPK fertilizers (160: 80: 60 kg ha-1). The experimental units were laid out in a completely randomized design (CRD) with five replications. The results showed that the combined use of NPK + press mud @ 4% caused a significant increase in grain numbers per cob (8.6%), weight of grains per cob (11.5%), grain yield, biological yield, harvest index, stalk yield, and oil and protein contents up to 11.5%, 6.3%, 19.7%, 12.6% and 12.0%, respectively as compared to the control treatment. The oil and protein contents were also improved significantly over the sole application of NPK fertilizer. Soil health was also improved due to the combined use of synthetic fertilizer with 4% press mud and 2% FYM. It is concluded that integrated use of NPK fertilizers and press mud @ 4% not only increased the quality and yield of maize, but it also improved soil health.

Building Soil Health and Fertility through Organic Amendments and Practices: A Review

Soil health and quality are foundational to agricultural sustainability and meeting global food security priorities. However, intensive farming practices have degraded soil ecosystems. Organic amendments and regenerative management practices can restore soil function by overcoming nutritional limitations, improving physical and biological properties, and promoting general soil and crop resilience. This review synthesizes research on major sources of organic soil amendments including animal manures, composts, cover crops, crop residues and living mulches. We describe their multifaceted edaphic and agronomic benefits from providing a slow release bank of macro and micronutrients, increasing soil organic matter, and stimulating beneficial microbial communities. Complementary and synergistic soil building practices are also covered, encompassing conservation tillage techniques like no-till, crop diversification via rotations and intercropping, and agroecological integration of trees and livestock. Although transitioning from degraded conventional systems requires patience as years of soil regeneration are needed to enable high system performance, outcomes consistently show integrated practices that minimize disturbance and maintain living ground cover while leveraging organic inputs can transform the foundation of agricultural systems by enhancing soil ecosystem function. Widespread adoption of this soil health paradigm can thereby enable sustainable intensification and resilience.

PEMBERDAYAAN IRT GAMPONG ALUE BEURAWE MELALUI BUDIDAYA TANAMAN HIDROPONIK SEBAGAI UPAYA PENINGKATAN EKONOMI KELUARGA

Hydroponic system technology is a method of farming using planting media other than soil, such as pumice, gravel, sand, coconut fiber, pieces of wood or foam. This is done because the function of soil as a support for plant roots and as an intermediary for nutrient solutions can be replaced by flowing or adding nutrients, water and oxygen through this medium. The aim of this community service activity was to provide science and technology to the housewives of Gampong Alue Beurawe regarding the hydroponic system as a solution to the limited agricultural land in Gampong Alue Beurawe. Then, the results of the cultivated vegetables using this hydroponic system can be marketed and become a source of income for partners. The implementation of this activity was carried out in several stages, namely: 1) observation and legalization, 2) implementation of training, 3) practice of cultivating plants using a hydroponic system, and 4) evaluation. From the results of implementing this activity, the target partner has a series of household scale hydroponic systems as a business. Apart from that, target partners also have knowledge and skills in farming using a hydroponic system. The resulting hydroponic plant harvest have been marketed and become income for partners. This activity is expected to be an opportunity for new entrepreneurial partners who will join the business group in the future to keep up with current developments, so that they are able to compete in this globalized world.

Sesame bacterial wilt significantly alters rhizosphere soil bacterial community structure, function, and metabolites in continuous cropping systems

Bacterial wilt is the leading disease of sesame and alters the bacterial community composition, function, and metabolism of sesame rhizosphere soil. However, its pattern of change is unclear. Here, the purpose of this study was to investigate how these communities respond to three differing severities of bacterial wilt in mature continuously cropped sesame plants by metagenomic and metabolomic techniques, namely, absence (WH), moderate (WD5), and severe (WD9) wilt. The results indicated that bacterial wilt could significantly change the bacterial community structure in the rhizosphere soil of continuously cropped sesame plants. The biomarker species with significant differences will also change with increasing disease severity. In particular, the gene expression levels of Ralstonia solanacearum in the WD9 and WD5 treatments increased by 25.29% and 33.61%, respectively, compared to those in the WH treatment (4.35 log10 copies g-1). The occurrence of bacterial wilt significantly altered the functions of the bacterial community in rhizosphere soil. KEEG and CAZy functional annotations revealed that the number of significantly different functions in WH was greater than that in WD5 and WD9. Bacterial wilt significantly affected the relative content of metabolites, especially acids, in the rhizosphere soil, and compared with those in the rhizosphere soil from WH, 10 acids (including S-adenosylmethionine, N-acetylleucine, and desaminotyrosine, etc.) in the rhizosphere soil from WD5 or WD9 significantly increased. In comparison, the changes in the other 10 acids (including hypotaurine, erucic acid, and 6-hydroxynicotinic acid, etc.) were reversed. The occurrence of bacterial wilt also significantly inhibited metabolic pathways such as ABC transporter and amino acid biosynthesis pathways in rhizosphere soil and had a significant impact on two key enzymes (1.1.1.11 and 2.6.1.44). In conclusion, sesame bacterial wilt significantly alters the rhizosphere soil bacterial community structure, function, and metabolites. This study enhances the understanding of sesame bacterial wilt mechanisms and lays the groundwork for future prevention and control strategies against this disease.

Soil quality increases with long-term chabazite-zeolite tuff amendments in arable and perennial cropping systems

The application of natural zeolites to improve soil quality and functioning has become highly popular, but we still miss information about the long-term effects on the soil due to its application. This study assesses the soil quality index (SQI) of three distinct agricultural soil systems 6–10 years after a single application of natural chabazite zeolite as a soil amendment. These soils exhibit different management practices: intensive arable (cereals), intensive perennial (pear) and organic perennial (olive). In the arable system, a zeolite application dosage of 5, 10 and 15 kg m−2 was tested and compared to unamended soil. In the two perennial systems, an application of 5 kg m−2 was tested against untreated reference sols. A set of 25 soil physical, chemical and biological parameters linked to soil health and quality were analysed at each experimental site. The dataset was investigated through Principal Component Analysis (PCA) to calculate the soil quality index (SQI) using linear scoring.In the arable-cereal field, the SQI doubled (0.3 to ca. 0.6 for all amendments) in chabazite-amended plots; a dose effect was not recognizable. In both perennial fields, the SQI was significantly higher in the chabazite-amended plots (5 kg m−2) with similar increases as compared to the arable-cereal field. At each site, the indicators selected by the PCA were different, indicating that chabazite addition impacted soil quality differently in each cropping system. Overall, the results highlighted a significant increase in soil quality with chabazite amendment, which confirms its potential for increasing soil health in the long-term.

Resistance of soil bacterial communities from montane heathland ecosystems in the Cantabrian mountains (NW Spain) to a gradient of experimental nitrogen deposition

Elevated atmospheric nitrogen (N) deposition on terrestrial ecosystems has become one of the most important drivers of microbial diversity loss on a global scale, and has been reported to alter the soil function of nutrient-poor, montane Calluna vulgaris heathlands in the context of global change. In this work we analyze for the first time the shifts of bacterial communities in response to experimental addition of N in Calluna heathlands as a simulation of atmospheric deposition. Specifically, we evaluated the effects of five N addition treatments (0, 10, 20, and 50 kg N ha−1 yr−1 for 3-years; and 56 kg N ha−1 yr−1 for 10-years) on the resistance of soil bacterial communities as determined by changes in their composition and alpha and beta diversities. The study was conducted in montane Calluna heathlands at different development stages (young and mature phases) in the southern side of the Cantabrian Mountains (NW Spain). Our results evidenced a substantial increase of long-term (10-years) N inputs on soil extractable N-NH4+, particularly in young Calluna stands. The alpha diversity of soil bacterial communities in mature Calluna stands did not show a significant response to experimental N addition, whereas it was significantly higher under long-term chronic N addition (56 kg N ha−1 yr−1 for 10-years) in young Calluna stands. These bacterial community shifts are mainly attributable to a decrease in the dominance of Acidobacteria phylum, the most representative in montane Calluna ecosystems, in favor of copiotrophic taxa such as Actinobacteria or Proteobacteria phyla, favored under increased N availability. Future research should investigate what specific ecosystem functions performed by soil bacterial communities may be sensitive to increased nitrogen depositions, which may have substantial implications for the understanding of montane Calluna ecosystems' stability.

Soil fertility impact on recruitment and diversity of the soil microbiome in sub-humid tropical pastures in Northeastern Brazil

Soil fertility is key point to pastures systems and drives the microbial communities and their functionality. Therefore, an understanding of the interaction between soil fertility and microbial communities can increase our ability to manage pasturelands and maintain their soil functioning and productivity. This study probed the influence of soil fertility on microbial communities in tropical pastures in Brazil. Soil samples, gathered from the top 20 cm of twelve distinct areas with diverse fertility levels, were analyzed via 16S rRNA sequencing. The soils were subsequently classified into two categories, namely high fertility (HF) and low fertility (LF), using the K-Means clustering. The random forest analysis revealed that high fertility (HF) soils had more bacterial diversity, predominantly Proteobacteria, Nitrospira, Chloroflexi, and Bacteroidetes, while Acidobacteria increased in low fertility (LF) soils. High fertility (HF) soils exhibited more complex network interactions and an enrichment of nitrogen-cycling bacterial groups. Additionally, functional annotation based on 16S rRNA varied between clusters. Microbial groups in HF soil demonstrated enhanced functions such as nitrate reduction, aerobic ammonia oxidation, and aromatic compound degradation. In contrast, in the LF soil, the predominant processes were ureolysis, cellulolysis, methanol oxidation, and methanotrophy. Our findings expand our knowledge about how soil fertility drives bacterial communities in pastures.

Planting grass enhances relations between soil microbes and enzyme activities and restores soil functions in a degraded grassland.

Forage culture is a common way to restore degraded grasslands and soil functions, in which the reconstruction of the soil microbial community and its relationship with extracellular enzyme activity (EEAs) can characterize the recovery effects of degraded grasslands. However, the impacts of forage culture on the interaction between soil microbes and EEAs and whether the recovery effect of soil functions depends on the varying degradation statuses remain unclear. We conducted a plantation of a dominant grass, Leymus chinensis, in the soil collected from severe, moderate, light, and non-degradation statuses in the Songnen grassland in northeastern China. We measured soil microbial diversity and soil EEAs, and predicted microbial functional groups using FUNGuild. The results showed that L. chinensis culture promoted soil bacterial alpha diversity and soil EEAs only in the moderate degradation status, indicating a dramatic dependence of the recovery effects of the grass culture on degradation status of the grassland. After planting L. chinensis for 10 weeks, a decreasing trend in the chemoheterotrophy and nitrate-reduction microbial functional groups was found. In contrast, the abundance of the nitrogen (N)-fixing microbial functional group tended to increase. The positive correlation between soil EEAs and the nitrate-reduction and N-fixing microbial functional groups was enhanced by planting L. chinensis, indicating that grass culture could promote soil N cycle functions. We illuminate that grass culture may promote the restoration of soil functions, especially soil N cycling in degraded grasslands, and the recovery effect may depend on the grassland degradation status. We emphasized that selection of the plant species for restoration of grasslands needs to consider the restoration effects of microbial functional groups and soil functions.

Simplified microbial network reduced microbial structure stability and soil functionality in alpine grassland along a natural aridity gradient

Increasing aridity is known to influence the diversity and function of soil microbiome. However, how it affects the microbial co-occurrence network are poorly understood, particularly in alpine ecosystem, which is one of the most vulnerable ecosystems. Here, we investigated the co-occurrence networks of soil microbiomes based on 60 sites along a natural aridity gradient across the Tibetan Plateau and evaluated their relationship with soil functionality. We hypothesized that increasing aridity could lead to a reduction in the complexity of microbial networks (e.g., the decreased number of nodes and edges, lower connectance, average degree, clustering coefficient and centralization degree), and this changed network complexity is strongly relate to microbial structure stability (network robustness and vulnerability) and soil functionality. Our results supported the hypothesis that the network complexities of bacteria, fungi and protists decreased along the aridity gradient. Microbial network complexity was significantly correlated with network robustness and vulnerability, suggesting that soil network complexity supports structure stability. Bacterial and fungal network complexities were strongly related to community functional traits (e.g., enzymes activities, carbohydrate and amino acid metabolism, C degradation genes), soil processes (e.g., CO2 and CH4 emission, N mineralization) and multifunctionality. This suggests a key relationship of microbial networks to alpine soil functionality, with a more significant impact observed in semi-arid and arid habitats than that in humid and semi-humid habitats. Plants played key roles in driving microbial network through altering soil organic C, with plant diversity having a greater impact in humid habitats, while plant biomass was more influential in semi-arid and arid habitats. Our results indicate that aridity-induced simplification of microbial communities can potentially weaken community stability and alpine soil functionality. Therefore, preserving the complexity of belowground communities is critical for ecosystem management and for predicting the ecological consequences of future aridification.

Imperatives for integrated weed management in vegetable production: Evaluating research and adoption

AbstractWeeds have a significant impact on vegetable production worldwide. These intensive cropping systems feature frequent tillage, fertilization and irrigation, providing ideal growing conditions for crops as well as certain weeds. Integrated weed management (IWM) can reduce reliance on herbicides by encouraging a systems approach to weed management. Using insights from global research and industry literature, we investigated the effectiveness of prevailing weed control methods, and evaluated emerging management practices and technologies for ongoing research and adoption. Weed control relies primarily on a relatively narrow range of herbicides as well as frequent tillage. Herbicides have negative impacts on soil, water and human health, while tillage impacts soil quality and function. Intensive cropping on smaller plots facilitates IWM, relying on multiple strategies including hand weeding, mulches, cover crops and cultural methods (e.g., crop rotations, timing). New herbicide options are suggested as an industry priority but are constrained by the lack of new chemistry and potential herbicide resistance. Refinement and adoption of non‐herbicide and emerging precision control methods into farm IWM in vegetables is more likely to be sustainable. This review is relevant to advanced vegetable production systems globally, but also to smallholder vegetable production in developing economies.

Dampak Penggunaan dan Pengolahan Tanah dalam Usahatani Sayuran Terhadap Infiltrasi Tanah Andisol di Kabupaten Kerinci

Andisol is a volcanic soil with a medium texture and a high organic matter content, so it is generally loose. However, the majority of vegetable farmers in Kayu Aro Barat District, Kerinci Regency carry out intensive soil cultivation in intensive land use (planting throughout the year, 2-3 times/year). Unfortunately, the role of tillage in soil and water conservation (SWC) is almost non-existent and even detrimental. One approach in SWC is the application of conservation tillage to control soil compaction so that soil infiltration is maintained. The research aims to determine the rate and capacity of Andisol soil infiltration and several factors that influence it, due to differences in the intensity of land use and cultivation in vegetable farming in Kebun Baru Village, Kayu Aro Barat District. The research used an exploratory-descriptive survey method. Observation and soil sampling points were determined using purposive stratified random sampling covering flat to sloping land, intensive land use and cultivation (planting 2-3 times/year + land cultivation 2 times/year), semi-intensive (planting 1-2 times/year + land cultivation once/year), and non-intensive (planting 1-2 times /year + land cultivation once/2 years), each land is planted with potatoes every year with various planting patterns. Soil infiltration rate was measured using a Double Ring Infiltrometer, and infiltration capacity was estimated using the Horton Equation. Soil infiltration rate and capacity are respectively 26.5 cm/hour (very fast) and 8.12 cm/hour (as is the infiltration capacity of loam-textured soil in general) on flat land with intensive land use and cultivation; much larger than other fields. On the other hand, the infiltration rate and capacity were 6.68 cm/hour (medium) and 2.27 cm/hour respectively (smaller than the infiltration capacity of silty loam soil in general), and the smallest, on sloping land that was used and cultivated not intensively. It is necessary to educate farmers to cultivate the land as necessary according to the characteristics of the soil and plant needs, to maintain the sustainability of soil function and building sustainable vegetable farming in West Kayu Aro District, Kerinci Regency.

Phylogenetic diversity drives soil multifunctionality in arid montane forest-grassland transition zone.

Exploring plant diversity and ecosystem functioning in different dimensions is crucial to preserve ecological balance and advance ecosystem conservation efforts. Ecosystem transition zones serve as vital connectors linking two distinct ecosystems, yet the impact of various aspects of plant diversity (including taxonomic, functional, and phylogenetic diversity) on soil multifunctionality in these zones remains to be clarified. This study focuses on the forest-grassland transition zone in the mountains on the northern slopes of the Tianshan Mountains, and investigates vegetation and soil characteristics from forest ecosystems to grassland ecosystems to characterize plant diversity and soil functioning, as well as the driving role of plant diversity in different dimensions. In the montane forest-grassland transition zone, urease (URE) and total nitrogen (TN) play a major role in regulating plant diversity by affecting the soil nutrient cycle. Phylogenetic diversity was found to be the strongest driver of soil multifunctionality, followed by functional diversity, while taxonomic diversity was the least important driver. Diverse species were shown to play an important role in maintaining soil multifunctionality in the transition zone, especially distantly related species with high phylogeny. The study of multidimensional plant diversity and soil multifunctionality in the montane forest-grassland transition zone can help to balance the relationship between these two elements, which is crucial in areas where the ecosystem overlaps, and the application of the findings can support sustainable development in these regions.

Soil invertebrate biodiversity and functionality within the intensively farmed areas of the Po Valley

Although agricultural activities can strongly affect soil biodiversity and health, with consequences on the provisioning of soil biota-mediated functions, their specific impact on soil invertebrate communities is far from being fully elucidated. In this study, the invertebrate communities associated with the soils of six habitat types, including both semi-natural and cropping systems, of one of the most intensively farmed areas in Europe, the Po Valley (North Italy), were characterized using the eDNA metabarcoding approach. The aims were to examine the variation in the taxonomic and functional diversity among the habitats and evaluate the relation between the disturbance caused by the main agronomic practices adopted in the area and the community diversity. Overall, the invertebrate communities were found to substantially differ in terms of taxonomic and functional diversity between the six habitats considered. For example, cornfield and rice paddy showed the highest diversity of annelids and the lowest one of nematodes. Woodland was found to host the most unique soil fauna, while grassland shared the majority of its soil taxa with almost all the other habitat types. The trophic groups had significantly lower diversity in specific habitats (e.g., carnivores, herbivores, microbivores in cornfield) suggesting that biological soil quality and ecosystem services provision may vary among them. Concerning agronomic practices, it was not observed an inverse relation between diversity and the disturbance they cause. In detail, while tillage and insecticide use negatively affected invertebrate diversity as a whole, specific soil taxa and trophic groups were idiosyncratically affected by the different agronomic practices (e.g., pesticide and fertilizer use was related to an increase of annelid and bacterivore diversity). In this regard, the peak of diversity observed for specific taxonomic and functional groups might be attributed to an impaired community balance. Altogether, the results obtained contribute to a more comprehensive understanding of the intricate interplay between agricultural practices and soil invertebrate communities, with implications for the awareness of soil health, ecosystem services provision and biodiversity conservation in agroecosystems.

[Effects of Combined Stress of High Density Polyethylene Microplastics and Chlorimuron-ethyl on Soybean Growth and Rhizosphere Bacterial Community].

With the vigorous development of agriculture in China， plastic mulch film and pesticides are widely used in agricultural production. However， the accumulation of microplastics （formed by the degradation of plastic mulch film） and pesticides in soil has also caused many environmental problems. At present， the environmental biological effects of microplastics or pesticides have been reported， but there are few studies on the combined effects on crop growth and the rhizosphere soil bacterial community. Therefore， in this study， the high density polyethylene microplastics （HDPE， 500 mesh） were designed to be co-treated with sulfonylurea herbicide chlorimuron-ethyl to study their effects on soybean growth. In addition， the effects of the combined stress of HDPE and chlorimuron-ethyl on soybean rhizosphere soil bacterial community diversity， structure composition， microbial community network， and soil function were investigated using high-throughput sequencing technology， interaction network， and PICRUSt2 function analysis to clarify the combined toxicity of HDPE and chlorimuron-ethyl to soybean. The results showed that the half-life of chlorimuron-ethyl in soil was prolonged by the 1% HDPE treatment （from 11.5 d to 14.3 d）， and the combined stress of HDPE and chlorimuron-ethyl had more obvious inhibition effects on soybean growth than that of the single pollutant or control. The HiSeq 2 500 sequencing showed that the rhizosphere bacterial community of soybean was composed of 20 phyla and 312 genera under combined stress， the number of phyla and genera was significantly less than that of the control and single pollutant treatment， and the relative abundances of bacteria with potential biological control and plant growth-promoting characteristics （such as Nocardioides and Sphingomonas） were reduced. Alpha diversity analysis showed that the combined stress significantly reduced the richness and diversity of the soybean rhizosphere bacterial community， and Beta diversity analysis showed that the combined stress significantly changed the structure of the bacterial community. The dominant flora of the rhizosphere bacterial community were regulated， and the abundances of secondary functional layers such as amino acid metabolism， energy metabolism， and lipid metabolism were reduced under combined stress by the analysis of LEfSe and PICRUSt2. It was inferred from the network analysis that the combined stress of HDPE and chlorimuron-ethyl reduced the total number of connections and network density of soil bacteria， simplified the network structure， and changed the important flora species to maintain the stability of the network. The results above indicated that the combined stress of HDPE and chlorimuron-ethyl significantly affected the growth of soybean and changed the rhizosphere bacterial community structure， soil function， and network structure. Compared with that of the single pollutant treatment， the potential risk of combined stress was greater. The results of this study can provide guidance for evaluating the ecological risks of polyethylene microplastics and chlorimuron-ethyl and for the remediation of contaminated soil.