Vegetable Fields Research Articles

Determination of water retention by the native field of the Pampa Biome with simulated rain

The Pampa was one of the most neglected biomes in Brazil, mainly due to its floristic composition distinct from the others. The expansion of agriculture and forestry are often linked to the advancement of negative impacts on the hydrology of this biome. However, there isn't enough information about the hydrological functioning of small basins with native vegetation in Pampa. The objective of this study is to evaluate the applicability of two different methodologies to determine water retention by native vegetation of the Pampa Biome, using a rainfall simulator. The methodology 1 used structured samples of native field vegetation and soil, and methodology 2 used only vegetation samples without the presence of soil; all of which were submitted to the application of simulated rain. With the obtained data, the amount of water that this vegetation retains during rainy events was estimated. Using method 1, we found estimated retention values of 5.4% and 10.9%, 18.6% and 27.8%. However, through method 2 we found estimated retention values of 8.5% and 12.7%. In any case, both methods showed significant values of water retention by this vegetation, being the variations found associated with the methodology itself, or the natural characteristics of each study area.

Determination of water retention by the native field of the Pampa Biome with simulated rain

Pampa was one of the most neglected biomes in Brazil, mainly due to its floristic composition distinct from the others. The expansion of agriculture and forestry are often linked to the advancement of negative impacts on the hydrology of this biome. However, there isn't enough information about the hydrological functioning of small basins with native vegetation in Pampa. The objective of this study is to evaluate the applicability of two different methodologies to determine water retention by native vegetation of the Pampa Biome, using a rainfall simulator. The methodology 1 used structured samples of native field vegetation and soil, and methodology 2 used only vegetation samples without the presence of soil; all of which were submitted to the application of simulated rain. With the obtained data, the amount of water that this vegetation retains during rainy events was estimated. Using method 1, we found estimated retention values of 5.4% and 10.9%, 18.6% and 27.8%. However, through method 2 we found estimated retention values of 8.5% and 12.7%. In any case, both methods showed significant values of water retention by this vegetation, being the variations found associated with the methodology itself, or the natural characteristics of each study area.

A Google Trends analysis of people's sense of seasons in Hokkaido

Accurate evaluation of the spatiotemporal variability of people's interest in seasons (i.e., their “sense of seasons”) is required to deeply understand temporal changes in the relationship between people and landscape under climate and societal changes. To this end, it is useful to analyze the time series of relative search volume (RSV) for relevant search terms extracted from Google Trends (GT) for any target period and target area. We examined the presence and absence of 12-month seasonality of the time series of RSV for about 300 representative search terms for Hokkaido in Japan, which has vast natural resources and is visited year-round by many tourists from Japan and abroad. In the case of searchers in both all of Japan and Hokkaido alone, search terms categorized into the foods, leisure, natural scenic spots, and seafood fields showed a strong trend toward 12-month seasonality of the time series of RSV, whereas those categorized into the Ainu (indigenous people) and people fields had weak trends for 12-month seasonality. People's sense of seasons in all of Japan or Hokkaido alone was likely associated with tourism (search terms in the animals, festivals, foods, leisure, natural scenic spots, seafood, tourist spots, and vegetation fields), as well as with animal and plant phenology (terms in the animals and vegetation fields), provisioning ecosystem services (terms in the foods and seafood fields), climate (terms in the climate field), and cultural ecosystem services (terms in the animals, festival, foods, leisure, natural scenic spots, seafoods, and vegetation fields). However, search terms with no 12-month seasonality were included in the tourist spots fields: they included many tourist spots visited by tourists all year around. Despite the need to appropriately select a huge number of representative search terms to reduce the effect of GT limitations and the uncertainty caused by unexpected and rapid temporal changes in RSV, the GT analysis allowed us to evaluate the spatiotemporal variability of people's sense of seasons regarding various objects in the landscape, including those related to tourism, under climate and societal changes.

Effects of Seven-Year-Optimized Irrigation and Nitrogen Management on Dynamics of Soil Organic Nitrogen Fractions, Soil Properties, and Crop Growth in Greenhouse Production

Exploring the temporal evolution dynamics of different soil organic nitrogen (N) components under different water–N management practices is a useful approach to accurately assessing N supply and soil fertility. This information can provide a scientific basis for precise water and N management methods for greenhouse vegetable production. The objective of this study was to investigate the effects of optimized irrigation and nitrogen management on the dynamics of soil organic nitrogen fractions, soil properties, and crop growth. This research was conducted from 2017 to 2023 in a greenhouse vegetable field in North China. Four treatments were applied: (1) high chemical N application with furrow irrigation (farmers’ practice, FP); (2) no chemical N application with drip irrigation (DN0); (3) 50% N of FP with drip irrigation (DN1); and (4) 75% N of FP with drip irrigation (DN2). The volume in drip irrigation is 70% of that in furrow irrigation. The results showed that in 2023 (after seven years of field trials), compared with FP, the soil organic carbon (SOC), total N, and water use efficiency of the DN1 and DN2 treatments increased by 15.9%, 11.4%, and 11.3% and 7.7%, 47.2% and 44.6%, respectively. However, there was no significant difference in the total crop yield except in the DN0 treatment. Soil organic N was mostly in the form of acid-hydrolyzed N (AHN). After seven years of optimized irrigation and N management, the DN1 treatment significantly increased the content of ammonium N (AN) and amino sugar N (ASN) in AHN compared with the FP treatment. The results of further analysis demonstrated that SOC was the main factor in regulating AHN and non-hydrolyzable N (NHN), while the main regulatory factors for amino acid N (AAN) and ASN in the AHN component were dry biomass and water use efficiency, respectively. From a time scale perspective, optimization of the water and N scheduling, especially in DN1 (reducing the total irrigation volume by 30% and the amount of N applied by 50%), is crucial for the sustainable improvement of soil fertility and the maintenance of vegetable production.

Study on the carbon sequestration effect of biochar in vegetable fields

This study was conducted using a field experiment methodology aimed at assessing the effects of biochar application on tomato growth and soil properties in greenhouse greenhouses. Biochar, a carbon-rich material produced by pyrolysis of biomass under anoxic conditions, has attracted attention for its potential in soil amelioration, carbon sequestration, and soil fertility enhancement. In this experiment, three biochar application levels of 0, 20, and 40 t/ha were designed to investigate the effects of different application rates on soil chemical properties and tomato growth.The study results showed that biochar application significantly increased soil pH by 0.05 to 0.1 units, which was beneficial in regulating acidic soil. Meanwhile, biochar application significantly increased total soil carbon content by 7.5 to 28.8%, indicating its effectiveness in enhancing soil carbon sequestration capacity. Although the enhancement of total soil nitrogen content by biochar was small (3.1 to 7.8%), this increase had a positive effect on crop growth. Considering the cost-effectiveness, this study recommends a one-time application of 40 t/ha of biochar, which can maintain the effect for at least 2 years, reducing the need for frequent applications and the associated economic costs.This study provides recommendations for optimization of biochar application and provides a scientific basis for sustainable agricultural development. By improving soil properties and increasing crop yields, this study contributes to the promotion of green development of agriculture and ecological civilization, and the realization of carbon and nutrient cycling in agroecosystems.The significance of this research focuses on evaluating the effects of biochar on soil properties and tomato production, thereby providing a scientific basis for fine-tuning application levels. Such optimization promotes sustainable farming practices, reduces agricultural waste emissions, enhances carbon and nutrient dynamics within agroecosystems, and reinforces the scientific foundation essential for progressing green agricultural development and building an ecological civilization.

Evaluation of In Situ FAPAR Measurement Protocols Using 3D Radiative Transfer Simulations

The fraction of absorbed photosynthetically active radiation (FAPAR) is one of the bio-geophysical Essential Climate Variables assessed through remote sensing observations and distributed globally by space and environmental agencies. Any reliable remote sensing product should be benchmarked against a reference, which is normally determined by means of ground-based measurements. They should generally be aggregated spatially to be compared with remote sensing products at different resolutions. In this work, the effectiveness of various in situ sampling methods proposed to assess FAPAR from flux measurements was evaluated using a three-dimensional radiative transfer framework over eight virtual vegetated landscapes, including dense forests (leaf-on and leaf-off models), open canopies, sparse vegetation, and agricultural fields with a nominal extension of 1 hectare. The reference FAPAR value was determined by summing the absorbed PAR-equivalent photons by either all canopy components, both branches and leaves, or by only the leaves. The incoming and upwelling PAR fluxes were simulated in different illumination conditions and at a high spatial resolution (50 cm). They served to replicate in situ virtual FAPAR measurements, which were carried out using either stationary sensor networks or transects. The focus was on examining the inherent advantages and drawbacks of in situ measurement protocols against GCOS requirements. Consequently, the proficiency of each sampling technique in reflecting the distribution of incident and reflected PAR fluxes—essential for calculating FAPAR—was assessed. This study aims to support activities related to the validation of remote sensing FAPAR products by assessing the potential uncertainty associated with in situ determination of the reference values. Among the sampling schemes considered in our work, the cross shaped sampling schemes showed a particular efficiency in properly representing the pixel scale FAPAR over most of the scenario considered.

Classifying Serrated Tussock Cover from Aerial Imagery Using RGB Bands, RGB Indices, and Texture Features

Monitoring the location and severity of invasive plant infestations is critical to the management of their spread. Remote sensing can be an effective tool for mapping invasive plants due to its capture speed, continuous coverage, and low cost, compared to ground-based surveys. Serrated tussock (Nassella trichotoma) is a highly problematic invasive plant in Victoria, Australia, as it competes with the species in the communities that it invades. In this study, a workflow was developed and assessed for classifying the cover of serrated tussock in a mix of grazing pastures and grasslands. Using high-resolution RGB aerial imagery and vegetation field survey plots, random forest models were trained to classify the plots based on their fractional coverage of serrated tussock. Three random forest classifiers were trained by utilising spectral features (RGB bands and indices), texture features derived from the Grey-Level Co-occurrence Matrix, and a combination of all the features. The model trained on all the features achieved an overallaccuracy of 67% and a kappa score of 0.52 against a validation dataset. Plots with high and low infestation levels were classified more accurately than plots with moderate or no infestation. Notably, texture features proved more effective than spectral features for classification. The developed random forest model can be used for producing classified maps to depict the spatial distribution of serrated tussock infestation, thus supporting land managers in managing the infestation.

Microplastics abundance associated with farmland use types and the impact on soil microbial communities: A case study in Southern China

To investigate the impact of various farmland use types on the spatial distribution of microplastics (MPs) and their correlation with microbial communities, 78 soil samples from distinct farmland use types (orchard, paddy field, and vegetable field) in Southern China were examined. Results revealed that the abundance of MPs ranged from 528 to 39,864 items/kg with a mean abundance of 10,562 items/kg, which were primarily 0–30 μm in size. A total of 32 polymer types were identified, with the main polymer being polyethylene terephthalate (PET, 28.8%), followed by polyvinyl chloride (PVC, 13.5%) and fluororubber (FKM, 9.5%). The abundance of MPs was highest in orchard field (8,896 ± 5,745 items/kg), followed by paddy field (4,176 ± 2,976 items/kg) and lastly vegetable field (2,967 ± 3,698 items/kg). Results of 16 S rRNA gene amplicon sequencing showed that the presence of MPs affected the bacterial distribution patterns. Compared with soil bacterial communities, the spatial dispersion and dissimilarity of plasticsphere communities were less variable. Notably, the predicted sequences related to xenobiotics biodegradation and metabolism became more abundant, thereby affecting the ecological function of soil. Overall, this study provides important data for further research on MP ecosystem risks associated with farmland use types.

Silver nano-colloid particles embedded on Langmuir-Blodgett film matrix of stearic acid serving as a SERS active sensor for detecting the herbicide ‘Paraquat’

The herbicide Paraquat, widely used for efficient weed control, poses significant health risks to humans viz., severe toxicity to vital organs and induction of neurodegenerative disorder like Parkinson’s disease, underscoring the urgent need for developing sensitive detection methods for the herbicide. This study aims at fabricating a novel SERS-active substrate SA-LB/Ag (silver nano-colloids adsorbed on Langmuir-Blodgett film of stearic acid), as a SERS based sensor having high sensitivity, uniformity, and reproducibility to detect ultra-trace amounts of paraquat. The sensor was built up by immersing bilayer LB films of SA in silver nano-colloid suspension, prepared by mixing silver nitrate and sodium borohydride with vigorous stirring. Quantitative evaluations establish a significant linear regression across the concentration spectrum (100 ppm to 75 ppb) of paraquat, with a remarkable 15 ppb limit of detection (LOD) value. In practical terms, this SERS based sensor exhibits notable proficiency in detecting paraquat residues in (a) agricultural water from rice and vegetable fields and environmental water from adjoining water-logged areas, and (b) soil extracts of the agricultural fields. Moreover, the minimum toxic concentration of paraquat at the developmental stage of zebrafish embryos and larvae is found to be approximately 20 ppb, implying that the SA-LB/Ag sensor is sensitive enough to determine the limiting toxic level of paraquat for animal systems. Thus, the designed sensor holds far-reaching implications in ensuring food safety, monitoring the environment, and framing regulatory measures for paraquat use.

Soil amendments altered arbuscular mycorrhizal fungal communities in cadmium-contaminated vegetable fields.

Soil amendments, including various types of fertilizers, are often used to control the uptake of heavy metals such as cadmium in cropping fields. The influence of these amendments on other members of the agroecosystem, such as arbuscular mycorrhizal fungi (AMF), remains less well investigated. Here, we established an experiment with the application of woody peat organic fertilizer and phosphate rock powder to examine its effects on AMF communities in two cadmium-contaminated vegetable crop fields (cucumber and pepper). We found that the application of phosphate rock powder enhanced soil phosphorus content, while the application of woody peat organic fertilizer enhanced soil nitrogen content, but neither influenced AMF abundance. We also found little influence of either amendment on measures of AMF diversity, except in one case where the Shannon index of diversity was lower in pepper fields amended with phosphate rock powder. We did, however, find significant shifts in the community composition and relative abundances of AMF taxa in the two vegetable fields, primarily as a result of shifts in the soil pH and nitrogen content.

Global Invasion of Thrips parvispinus (Karny) (Thysanoptera: Thripidae) Across Three Continents Associated With Its One Haplotype

ABSTRACTThrips parvispinus (Karny) is an exotic pest that has invaded many regions around the world in the last three decades. It was first detected in Florida in 2020 on ornamental plants (Hoya and Anthurium) in greenhouses and subsequently on ornamental plants in residential landscapes (Gardenia) in 2021. However, its first report on open vegetable field crops (Capsicum) in Florida was in 2022. We conducted field surveys and genetic analysis to answer three questions: (1) Is the population of T. parvispinus that invaded Florida the same as the one that has spread globally in the last few decades? (2) Is the host expansion to Capsicum in Florida a new population or the extension of the existing population reported on ornamental plants? and (3) What are the native and invaded distribution ranges of T. parvispinus? We analysed the genetic variation in the mitochondrial gene cytochrome oxidase I (COI) to address these questions. The global genetic diversity analysis of T. parvispinus revealed 18 haplotypes (populations) worldwide based on available data, but only one population (Hap1) invaded three continents: Africa, Europe, and North America. Based on available data, the highest haplotype diversity was observed in India, suggesting India may be part of the presumed native range (South and Southeast Asian countries) of T. parvispinus. Our survey of retail plant stores across 10 Florida counties indicated that plant trade is the source of T. parvispinus in open vegetable field crops and ornamental landscape plants. The outcome of this study will assist with regulatory and management decisions of T. parvispinus in Florida and elsewhere.

Macro- and micro-plastic accumulation in soils under different intensive farming systems: A case study in Quzhou county, the North China Plain

The macroplastics (MaPs) and microplastics (MiPs) polluting agricultural soils raise great concerns. Unfortunately, scientists know little about the occurrence of MaPs/MiPs in soil among different farming systems. In this study, we analyzed MaPs/MiPs in soils (0–30 cm) collected from six different farming systems (wheat-maize rotations, cotton, vegetables, permanent orchards, greenhouses with and without mulching) in Quzhou county, the North China Plain, by using fluorescence microscope and micro-Fourier transform infrared spectroscopy. The results showed that the abundance of MaPs and MiPs ranged from 0.2 to 46.8 kg ha−1, and 4.1 × 103–3.7 × 104 items kg−1, respectively. The prominent colors of the MaPs were white and black. The predominant shape, size and chemical composition of soil MiPs were fragments (45–62%), <1 mm (98–99%), and polyethylene (38–43%), respectively. MaPs were mainly detected in the 0–10 cm soil layer. MiP abundance in the 0–10 cm soil layer was significantly higher than that in the 20–30 cm soil layers among different farming systems, except for the fields with wheat-maize rotations and permanent orchards (p < 0.05). Overall, cotton fields showed the highest MaP and MiP abundance, followed by vegetable fields and orchards. Redundancy analysis revealed that tillage practices and plastic film management greatly influence the size distribution of MiPs. A strong negative correlation between large-sized plastic fractions (0.2–1 mm) and tillage frequency was tested while the years of application of plastic films and the abundance of plastic residues showed a strong positive correlation with small-sized plastic fractions (<0.2 mm). Our findings conclude that agricultural mulch films are an important source of MaPs and MiPs in agricultural soil and distributions are strongly influenced by agricultural management practices and farming systems. Further studies should take farming systems and farming practices into account, thereby exploring the potential mechanisms of plastic fragmentation and granularization in agricultural soil.

Spatial-temporal Distribution and Ecological Risk of Antibiotics in the Soils of a Typical Agricultural Watershed in the Three Gorges Reservoir Area

In order to understand the spatial-temporal distribution and ecological risk of antibiotics in the soil of an agricultural watershed in the Three Gorges Reservoir area, the topsoil samples were collected at 26 sites in the Wangjiagou small watershed, Fuling District, Chongqing in spring, summer, autumn, and winter of 2022, and 21 antibiotics with five classes were determined using solid phase extraction and ultra-performance liquid chromatography-tandem mass spectrometry. The content levels and spatial-temporal distribution of antibiotics were analyzed, the correlations between antibiotic contents and soil physicochemical factors were discussed, and the potential ecological risk of antibiotics in the soil was evaluated using the risk quotient method. The results showed that the detection rates of 21 antibiotics were 0-100% with the range of ND-219.5 μg·kg-1, and those of tetracyclines （TCs）, quinolones （FQs）, and chloramphenicols （CAPs） reached 100% in all four seasons. The total antibiotic content ranged from 14.35 to 504.1 μg·kg-1 with the average value of 149.7 μg·kg-1, and the average contents of the five classes of antibiotics showed a decreasing trend of TCs （77.95 μg·kg-1）, FQs （34.96 μg·kg-1）, CAPs （28.14 μg·kg-1）, sulfonamides （SAs, 7.15 μg·kg-1）, and macrolides （MLs, 1.48 μg·kg-1）. The antibiotic contents of soils during autumn and winter were significantly higher than those in summer （P &lt; 0.05） and showed an overall variation trend of first decreasing and then increasing with the season and a distribution situation of "low in the west and high in the east." The sites with high antibiotic contents were mainly concentrated in vegetable fields, residential areas, and dry lands. In spring soils, the contents of tylosin （TYL） （P &lt; 0.01）, tetracycline （TC） （P &lt; 0.01）, doxycycline （DXC）, and sulfamethodiazine （SMR） （P &lt; 0.05） were significantly negatively correlated with soil pH. In summer soils, total phosphorus （TP） had significantly positive effects on the contents of sulfamethoxazole （SFZ） and TC （P &lt; 0.05） and had extremely significant positive effects on sulfamethoxazole （SMX）, SMR, and ofloxacin （OFL） （P &lt; 0.01）. Total nitrogen （TN） had significantly positive effects on the contents of SMX （P &lt; 0.01） and SMR （P &lt; 0.05）, and soil organic matter （SOM） had significantly positive effects on the contents of TC and enrofloxacin （ENR） （P &lt; 0.05）. However, ciprofloxacin （CIP） （P &lt; 0.001）, sulfampyridine （SPD）, norfloxacin （NOR）, and TYL contents （P &lt; 0.05） were significantly negatively correlated with soil pH. In autumn soils, TN significantly negatively affected CIP content （P &lt; 0.05）； the contents of sulfadiazine （SDZ）, TC, and DXC were negatively affected by soil pH （P &lt; 0.05）； and cation exchange capacity （CEC） significantly positively affected the contents of TC and SFZ （P &lt; 0.05）. In winter soils, TP had a significantly positive effect on TYL content, and TN had a significantly positive effect on SFZ content （P &lt; 0.05） and an extremely positive effect on sulfamethoxine （SMM） （P &lt; 0.001）. Chlorotetracycline （CTC） （P &lt; 0.01）, CIP （P &lt; 0.01）, thiamphenicol （TAP） （P &lt; 0.001）, chloramphenicol （CAP） （P &lt; 0.001）, oxytetracycline （OTC） （P &lt; 0.001）, and sulfadimidine （SM2） （P &lt; 0.05） were significantly negatively correlated with soil pH, and CEC had a significantly negative effect on SDZ content （P &lt; 0.05）. The soils in the Wangjiagou agricultural small watershed were mainly threatened by SMX, SDZ, TC, DXC, erythromycin, NOR, OFL, CIP, and ENR, and their ecological risks should not be ignored.

Heavy metal contamination and potential health risks in upland rice-producing soils of rotational shifting cultivation in northern Thailand

Rotational shifting cultivation (RSC) is commonly practiced in northern Thailand for upland rice cultivation, primarily for household consumption. However, the potential health risks from heavy metal contamination in these soils have not been thoroughly explored. This study aimed to evaluate the contamination of six heavy metals (Arsenic (As), Mercury (Hg), Cadmium (Cd), Lead (Pb), Copper (Cu), and Chromium (Cr)) in upland rice across RSC fields with varying fallow periods and assess the associated health risks from rice consumption. Four RSC fields with 5, 6, 10, and 12-year fallow periods were examined. The RSC-6Y and RSC-12Y fields were used for upland rice cultivation in 2022, while the RSC-5Y and RSC-10Y fields were cultivated in 2023. The geo-accumulation index (Igeo) was calculated, and translocation factors (TF) were assessed for the transfer of heavy metals from soil to straw (TFStraw/Soil), straw to grain (TFGrain/Straw), and soil to grain (TFGrain/Soil). The results indicated that after burning vegetation in the RSC fields, the highest concentrations of Pb, Cr, and Hg were found in the ash. In RSC soils, Cu, Cr, As, Pb, and Hg levels were below reference standards, with Cd undetected. In rice grains, the order of concentration was Pb > Cu > Cr > As, with Hg and Cd undetected. Pb levels in rice grains exceeded the safety threshold. Igeo values indicated no contamination to moderate contamination across sites, with negative Igeo values for Cr and Cu, and zero values for Cd. The TF results showed limited transfer of As, Hg, and Cd from soil to rice plants (TFStraw/Soil < 0.1), but notable transfer for Pb, Cr, and Cu. Pb was readily transferred from soil to grain (TFGrain/Soil), posing a potential health risk. The study highlights potential non-carcinogenic and carcinogenic risks from heavy metal exposure, particularly Pb, and underscores the need for further research to determine contamination sources and mitigation strategies.

Identifying construction technologies and environmental connections at the Iron Age IIA settlement of Kh. es-Suwweida, Israel: A microarchaeological study

The first season of excavations at Kh. es-Suwweida in northern Israel revealed strata from the late Iron Age IIA consisting of a series of massive fortification walls, rooms and internal compartments with potential floors. A microarchaeological investigation was undertaken to add high-resolution contextual and compositional data to the field evidence and characterize site formation processes, construction materials and technologies, and use of environmental resources. We applied a micro-archaeological approach to study sediments and archaeological materials via micromorphology, Fourier-transform infrared (FTIR) spectroscopy and micro-spectroscopy, and phytolith and pollen analysis. Two main construction technologies were identified: lime plasters produced from mixtures of pyrogenic lime and non-pyrogenic crushed chalk, and mudbricks prepared from sedimentary materials. An in situ lime constructed floor with multiple re-plastering and activity zones associated with the remains of a degraded mudbrick structure was reconstructed in one locality, and a collapsed burnt lime and mudbrick building with a wooden superstructure was reconstructed in another locality. The micro-archaeobotanical analyses identify domesticated barley, the cultural utilisation of grasses on-site, and a hinterland vegetation of open fields. The combined microarchaeological evidence enables a more detailed reconstruction of the variability in construction technologies and the sequence of collapse and degradation processes in an Iron Age settlement.

Does the herbicide napropamide exhibit enantioselective effects across genus plasmid transfer from Escherichia coli to Bacillus subtilis?

The dissemination of plasmid-borne antibiotic resistance genes (ARGs) into the environment is an urgent concern. However, the enantioselective effects of herbicides on plasmid conjugation among bacterial genera and their underlying mechanisms remain unclear. This study demonstrates for the first time that the herbicide napropamide (NAP), commonly used in vegetable fields, exhibits a concentration-dependent effect on the transfer efficiency of the pBE2R plasmid from Escherichia coli to Bacillus subtilis. Notably, at a concentration of 5mgL-1, R-NAP increased transfer efficiency by threefold compared to the S-enantiomer. Scanning electron microscopy revealed that R-NAP caused less structural damage to bacteria than S-NAP but more effectively reduced cell wall components (lipopolysaccharides and peptidoglycan) in donor and recipient bacteria, increasing reactive oxygen species levels and membrane permeability. Transcriptomic analysis indicated that NAP enantiomers altered the expression of genes related to membrane transport activity and transposons. Cross-domain network analysis identified yieK, ygeH, and ydbL as key genes mediating conjugation transfer. Molecular docking results showed that NAP likely interacts hydrophobically with the active sites of the proteins encoded by these genes. In conclusion, herbicides like R-NAP should be carefully managed in fields irrigated with livestock manure to mitigate the risk of ARG transfer and accumulation in crops.

Dam break flow through rigid-emergent vegetation

Dam failures pose a significant threat to life and property. This study investigates the potential of rigid emergent vegetation to attenuate dam break waves, reducing their destructive impact. Experiments explored the effect of varying vegetation field lengths on wave propagation. Wooden cylinders with consistent diameter (1.0 cm) and density (0.067) simulated the rigid vegetation in a straight, flat rectangular channel. Four different vegetation lengths and three bore conditions for different reservoir and tailwater depths were examined to analyze their influence on dam break wave behavior. The results demonstrate the effectiveness of vegetation in dissipating wave energy, leading to a rapid decrease in wave height and celerity. Interestingly, increasing vegetation length significantly attenuates the wave height downstream of the vegetation zone, while having no significant impact on the reflection wave height upstream of the vegetation. This finding highlights the targeted effectiveness of strategically placed vegetation in shielding downstream areas. The study also clarifies that celerity can be calculated using shallow water equations for both upstream and downstream regions with wave height and tailwater depth. However, within the vegetation, drag forces significantly reduce celerity. A novel equation, derived from wavefront profiles, was proposed and validated to accurately calculate celerity within the vegetation field. These findings provide valuable data for validating numerical models simulating dam break wave interactions with vegetation.Graphical abstract

Changes in weed vegetation across transects in maize fields

Weed vegetation in Central Europe has strongly changed during the last decades in response to changing agricultural practices. In addition, the cultivation of certain crops such as maize has expanded strongly. Fields are characterized by gradients from the edge to the interior, which may have ramifications on the weed vegetation. Here, we analyzed the composition of weed vegetation in maize fields from the edge to the interior documented by 101 transects consisting of three plots (10 m2) from Central Europe. In total, 203 species were recorded, including 107 (52%) natives, 48 (24%) archaeophytes, and 48 (24%) neophytes. While the edge plots had a median species richness of nine species, the central plots (10 m from the field edge) and the interior plots (50 m from the field edge) both had a median of four species. Weed species cover declined more drastically from a median of 28.9% total cover to 6.2% to 5.0%. Community indices (based on Ellenberg Indicator Values) changed along transects. Mean community index for light decreased towards the center, while the community index for moisture increased. The community index for nutrients increased from the edge to the central plot, but not to the interior plot. Species turnover was significant between the edge, central and interior plots. Species richness of the transects was influenced by landscape context and climate. Mean annual temperature, the amount of surrounding forests and maize fields were significant negative predictors of species richness, whereas surrounding water bodies, ruderal vegetation and built-up areas were significant positive predictors. Given that maize cultivation has rapidly expanded during the last decades, making it one of the most important crops in Central Europe, our study provides important insights into the composition of weed vegetation of a major, yet understudied component of modern agricultural landscapes.

Plant Species Diversity and Composition Differ Significantly Between the Boundaries of Kettle Holes and Field Borders.

The boundaries around habitat islands in agricultural fields are rather unexamined, although they may be an important part of agroecosystems in some regions. In this study, we surveyed field boundaries in northeastern Brandenburg both at outer field borders and around kettle holes, which are typical habitat islands in the region. We examined, described, and compared the plant species diversity and composition at both the inner and outer field boundaries in the arable fields (crop edge) as well as in permanent vegetation (field margins). Diversity was assessed and compared with Hill diversity values, using the iNext framework. Non-metric multidimensional scaling and permutational analysis of variance were used to compare species composition at different field boundaries and to search for variables that drive species composition at the local scale. The results revealed that both species diversity and composition differed significantly between the inner and outer boundary along the crop edges and at the field margins. Local site conditions, namely a moisture gradient, influenced the species composition of the field margins, resulting in differences between the inner and outer field margins. Mitigated through crop growth and cover, the moisture gradient influenced also the species composition of the inner and outer crop edges, despite the management practices on the fields were the same.

Assessing on-site plastics fragmentation: Linking macroplastics litter to microplastics pollution in vegetable fields

This study proposes a novel approach to determine whether farmers act as a pollution source of microplastics through macroplastic mismanagement or if they are temporary hosts of in-transit microplastics. Using a case-study approach, it was hypothesized that 90 % of soil microplastics would trace back to macroplastic waste mismanaged by farmers. To determine the amount of soil microplastics, linear transects were established and microplastic litter was counted and classified. Additionally, composite soil samples were used to count and colour-classify microplastics. The Kendall correlation was used to differentiate between the colour ranks of macro- and microplastics to discriminate between plastic on-site fragmentation or exogenous plastic pollution. For this, 37 vegetable farms in central Chile were assessed after the growing season. Farms showed lower microplastic counts than previously reported for similar productive conditions (3.68 ± 3.28 u/kg). A median colour correlation of 0.43 (IQR = 0.18–0.55) was observed between macro- and microplastics. Only in 25 % of the studied fields did on-site plastic fragmentation predominate over exogenous plastic pollution. The applied approach is simple to implement and does not require specialized laboratory equipment. We hope that the proposed methodology will serve in environmental monitoring to evaluate adherence to good agricultural practices and to guide pollution-prevention measures.