Real Field Conditions Research Articles

Specific and conserved patterns of microbiota-structuring by maize benzoxazinoids in the field

BackgroundPlants influence their root and rhizosphere microbial communities through the secretion of root exudates. However, how specific classes of root exudate compounds impact the assembly of root-associated microbiotas is not well understood, especially not under realistic field conditions. Maize roots secrete benzoxazinoids (BXs), a class of indole-derived defense compounds, and thereby impact the assembly of their microbiota. Here, we investigated the broader impacts of BX exudation on root and rhizosphere microbiotas of adult maize plants grown under natural conditions at different field locations in Europe and the USA. We examined the microbiotas of BX-producing and multiple BX-defective lines in two genetic backgrounds across three soils with different properties.ResultsOur analysis showed that BX secretion affected the community composition of the rhizosphere and root microbiota, with the most pronounced effects observed for root fungi. The impact of BX exudation was at least as strong as the genetic background, suggesting that BX exudation is a key trait by which maize structures its associated microbiota. BX-producing plants were not consistently enriching microbial lineages across the three field experiments. However, BX exudation consistently depleted Flavobacteriaceae and Comamonadaceae and enriched various potential plant pathogenic fungi in the roots across the different environments.ConclusionsThese findings reveal that BXs have a selective impact on root and rhizosphere microbiota composition across different conditions. Taken together, this study identifies the BX pathway as an interesting breeding target to manipulate plant-microbiome interactions.4atbM_n1-Xmh1rBaQ1rPHqVideo

Novel Experimental Technique for Simulating Near Wellbore Integrity Challenges at Field Conditions

A new and innovative experimental setup for investigating borehole integrity issues is presented. The setup comprises an X-ray transparent high-pressure cell with separate and independent controls on pore pressure, confining pressure, and casing pressure. This allows the setup to mimic a scaled down wellbore system, hence setting ground for studies at realistic field conditions. X-ray computed tomography (CT) is used to provide 3D visualization and quantification of both stress-induced fractures and debonding of the cement sheath (from casing and formation) at in-situ conditions. The pressure cell accommodates a steel tube at the center simulating the well casing which is cemented to a surrounding rock. Each concentric layer of material within the cell, i.e., the inner steel tubing, the surrounding rock and the confining sleeve, can be separately pressurized through dedicated ports in the cell's endcaps. In this work, the setup and the results from some of the initial tests carried out are reported. The application of different amounts of pressure to the inner and outer casing induces fractures in the cement and surrounding rock formation. Results show the evolution of radial cracks in the cement sheath and the sandstone with increased casing pressure, with and without confining and pore pressure. The findings indicate fundamental differences between the outcome of the experimental results where pore and confining pressures are applied in addition to only the casing pressure which has been the conventional approach in this type of studies so far. By applying pressure difference between the well and the rock formation, geometry and permeability of the stress-induced fracture network can be analyzed. The measured parameters, together with the geometry of the cracks recorded in these experiments provide a consistent and valuable input for numerical simulations and set the ground for addressing remediation and mitigation challenges.

Blinded evaluation of airborne methane source detection using Bridger Photonics LiDAR

Controlled, fully-blinded methane releases and ancillary on-site wind measurements were performed during a separate airborne survey of active oil and gas facilities to quantitatively evaluate the capabilities and potential utility of the Bridger Photonics LiDAR-based airborne Gas Mapping LiDAR™ (GML) methane measurement technology under realistic field conditions. Importantly, although Bridger Photonics knew there was a ground team working in the area to deploy wind sensors as part of the broader survey of facilities, they had no knowledge whatsoever that controlled releases were taking place and were not informed of this until all data processing was complete. Thus, the presented data allow a true, fully-blinded assessment of the airborne technology's ability to both detect and locate unknown methane sources within active oil and gas facilities, as well as to quantify their release rates. Results were used to derive a lower-sensitivity limit threshold as a function of wind speed, which matches well with the broader field survey results. Comparison of measurement results with and without the benefit of on-site wind data reveal that uncertainty in the GML source quantification is a direct linear function of the uncertainty in the wind speed. Quantification uncertainties (1σ) of ±31–68% can be expected for sources near the sensitivity limit. The derived sensitivity limit function was incorporated into exploratory simulations using the Fugitive Emissions Abatement Simulation Toolkit (FEAST), which suggest that the Bridger GML technology has comparable performance to optical gas imaging (OGI) camera surveys both in terms of fraction of total emissions detected and anticipated net mitigation. The relative performance of the Bridger GML technology would be expected to improve or worsen as the assumed underlying distribution of source magnitudes becomes more or less positively skewed (i.e. more or less dominated by larger sources such as tank vents). Overall, the Bridger GML technology is shown to be capable of detecting, locating, and quantifying individual sources at or below the magnitudes of recent regulated venting limits. The presented detection sensitivity function will be useful for modelling potential alternate leak detection and repair strategies and interpreting future airborne measurement data.

Earthworms did not increase long-term nitrous oxide fluxes in perennial forage and riparian buffer ecosystems

Many laboratory and mesocosm studies have demonstrated that earthworms influence nitrogen (N) cycling reactions and produce nitrous oxide (N2O) in well-aerated soils, but whether earthworms can stimulate N2O fluxes in realistic field conditions remains to be determined. We conducted two field experiments, in perennial forage agroecosystems for 2 yr and agriculture riparian buffers for 1 yr, to compare N2O fluxes from enclosures with ambient and artificially elevated earthworm populations. Despite a short-term (< 3 month) increase in mean N2O fluxes from the perennial forage enclosures with artificially elevated earthworm populations, this effect disappeared within 1 yr, with no significant difference (p> 0.05) in mean N2O flux from enclosures in either field experiment. The elevated earthworm populations declined and stabilized at the same level as the ambient earthworm populations within 1–2 yr after the field experiments began. The homeostatic regulation of earthworm populations under field conditions could be due to inter- and intra-specific competition, related to limitation in the food supply and habitat preferred by earthworms. Mean N2O fluxes in the perennial forage fields were negatively correlated with soil moisture, but not related to earthworm populations. In the riparian buffers, the average N2O flux was negatively correlated with vegetation cover, and positively correlated with soil moisture and the size of the earthworm population at the end of the study. Our results suggest that the effects of earthworm addition on N2O emissions in laboratory studies can not necessarily be extrapolated to field settings. Earthworm field experiments that continue in the longer-term and in a variety of ecosystems should improve our understanding of the seasonal and environmental variability in earthworm activity and N2O production under field conditions.

Contrasting response of native and non‐native plants to disturbance and herbivory in mountain environments

AbstractAimClimate warming and increasing human disturbance are expected to promote non‐native plant invasions in mountain ecosystems. Although biological invasions are also expected to be modulated by biotic interactions, it is still not clear how invertebrate herbivores can affect plant invasion dynamics. Using a large manipulative experiment, we aimed at testing: (1) the effect of soil disturbance and elevation on native and non‐native plant communities, and (2) the effect of plant‐herbivore interactions, nitrogen deposition, and elevation in driving plant establishment after soil disturbance.LocationEuropean Alps, NE Italy.TaxonVascular plants.MethodsWe selected remote, uninvaded dry semi‐natural grasslands along the core elevational range of non‐native plants in the European Alps (c. 100–1300 m) and manipulated soil disturbance, nitrogen deposition, and invertebrate herbivory. Then, we followed the natural establishment under real field conditions of both native and non‐native plants over one growing season. We used generalized mixed‐effects models to test the effects of the experimental treatments.ResultsNative and non‐native species showed contrasting responses to soil disturbance and elevation. Low elevations and disturbance promoted non‐native success, while affecting native species diversity negatively. Two‐thirds of the experimental sites acquired novel non‐natives after disturbance. Most of the observed non‐natives were not present in the surrounding vegetation as mature plants, indicating that propagules were able to reach even remote natural areas. While current N deposition levels did not affect plant establishment, we found that after disturbance invertebrate herbivory might play an important role in facilitating non‐native invasions by reducing native cover.Main conclusionsOur findings show that highly resistant ecosystems such as continuous grasslands can be easily invaded once the resident vegetation has been removed, and that natural herbivory pressure from invertebrates might amplify the negative effects of disturbance on resident native species irrespective of elevation. Together, these results indicate increasing risks of future plant invasions on mountains under global change.

Combined use of different nanoparticles effectively decreased cadmium (Cd) concentration in grains of wheat grown in a field contaminated with Cd

Cadmium (Cd) accumulation in arable lands has become a serious matter for food security. Among various approaches, the application of nanoparticles (NPs) for remediation of contaminated water and soils is attaining more popularity worldwide. The current field experiment was executed to explore the impacts of single and combined use of ZnO NPs, Fe NPs and Si NPs on wheat growth and Cd intake by plants in a Cd-contaminated field. Wheat was sown in a field which was contaminated with Cd and was irrigated with the raw-city-effluent while NPs were applied as foliar spray alone and in all possible combinations. The data revealed that straw and grain yields were enhanced in the presence of NPs over control. Chlorophyll, carotenoids contents and antioxidants activities were enhanced while electrolyte leakage was reduced with all NPs over control. In comparison with control, Cd uptake in wheat straw was reduced by 84% and Cd uptake in grain was reduced by 99% in T8 where all three NPs were foliar-applied simultaneously. Zinc (Zn) and iron (Fe) contents were increased in those plants where ZnO and Fe NPs were exogenously applied which revealed that ZnO and Fe NPs enhanced the bio-fortification of Zn and Fe in wheat grains. Overall, foliar application of different NPs is beneficial for better wheat growth, yield, nutrients uptake and to lessen the Cd intake by plants grown in Cd-contaminated soil under real field conditions.

Toxicity of fipronil and 2,4-D formulations (alone and in a mixture) to the tropical amphipod Hyalella meinerti.

Conventional farming uses a large volume of pesticides that may reach aquatic ecosystems. This is also the case for the insecticide fipronil and the herbicide 2,4-D, which are widely used in many crops. This study aimed at evaluating the individual and mixture toxicity of these pesticides to the tropical amphipod Hyalella meinerti. To this end, acute toxicity tests (96 h) were conducted. Chronic bioassays (10 days) were also carried out, in which the body length and dry biomass were evaluated as endpoints. In addition, a complete factorial mixture chronic toxicity test was carried out. H. meinerti was sensitive to fipronil in the acute toxicity tests, with a LC50-96-h of 0.86 μg L-1 (95% CI 0.26-0.46), and no acute effects were observed after 2,4-D exposure even at the highest test concentration of 100 mg L-1. In the chronic toxicity tests, all tested concentrations of both pesticides decreased the growth of H. meinerti, in which losses on biomass reached 45% and 65% for 2,4-D and fipronil, respectively. The pesticide mixture indicated antagonism although it still significantly decreased the body growth. The results obtained indicate a high sensitivity of H. meinerti exposed to environmentally realistic concentrations, demonstrating that there are risks for the species in real field conditions.

Improving hole cleaning in horizontal wells by using nanocomposite water-based mud

Efficient cuttings transport is important for achieving safe and successful drilling operations. However, poor hole cleaning is considered to be one of the main issues that happens frequently in horizontal and highly deviated wells. The selection of the drilling fluids with enhanced rheological properties is one of the effective methods to increase cuttings transportation efficiency. The major purpose of the present research is to investigate the application of silica (SiO2) nanoparticles in improving hole cleaning in extended reach drilling (ERD) operations. Nanocomposite drilling fluids were prepared by adding silica nanoparticles into water-based mud (WBM) at different weight percent concentrations (0.1–1.5 wt%). The flow loop experiments were performed on a sophisticated purpose-built flow rig by circulating the tested fluid samples into the test section in a horizontal position, considering the influence of drill pipe rotation, flow rates, cuttings sizes, mud density, and drill pipe eccentricity. In addition, the study covers the impacts of laminar, transition, and turbulent flow regimes. The goal of such variation in the operational parameters is to simulate real field conditions. The results indicated that the addition of the silica nanoparticles to WBM increases the colloidal interactions with cuttings, therefore leading to a substantial enhancement in cuttings removal efficiency especially with the higher concentration of silica nanoparticles. It was shown that nanoparticles in drilling fluid increase cuttings transport by 20.32%–32.75% for different nanocomposite water-based drilling fluids used in this study. The proposed investigation demonstrates the feasibility of using silica nanoparticles in WBM to enhance the capability of drilling fluids in transporting and circulating drilled cuttings out of the wellbore. Furthermore, the results of this project would provide a more reliable understanding of the relationship between drilling operation parameters and hole cleaning performance in ERD operations.

On Coding and Decoding Reconfigurable Radiation Pattern Modulation Symbols

In this paper, we propose the theoretical framework for a reconfigurable radiation pattern modulation (RRPM) scheme, which is reminiscent of the index modulation technique. In the proposed scheme, information is encoded using far-field radiation patterns generated by a set of programmable radiating elements. A considerable effort has been invested to allow for high transmission of the reconfigurable radiation pattern symbols; yet, the receiving system has received little attention and has always been considered ideal. Depending on the number of receivers and their respective positions, two variables are considered here for data transmission: the sampling resolution and the fraction of the covered space by the receiving antennas. Hence, we quantitatively investigate their effect on the bit-error-rate (BER) by making use of a limited number of measurements that approximate the behavior of the system under real-field conditions.

Human Activity Recognition through Recurrent Neural Networks for Human–Robot Interaction in Agriculture

The present study deals with human awareness, which is a very important aspect of human–robot interaction. This feature is particularly essential in agricultural environments, owing to the information-rich setup that they provide. The objective of this investigation was to recognize human activities associated with an envisioned synergistic task. In order to attain this goal, a data collection field experiment was designed that derived data from twenty healthy participants using five wearable sensors (embedded with tri-axial accelerometers, gyroscopes, and magnetometers) attached to them. The above task involved several sub-activities, which were carried out by agricultural workers in real field conditions, concerning load lifting and carrying. Subsequently, the obtained signals from on-body sensors were processed for noise-removal purposes and fed into a Long Short-Term Memory neural network, which is widely used in deep learning for feature recognition in time-dependent data sequences. The proposed methodology demonstrated considerable efficacy in predicting the defined sub-activities with an average accuracy of 85.6%. Moreover, the trained model properly classified the defined sub-activities in a range of 74.1–90.4% for precision and 71.0–96.9% for recall. It can be inferred that the combination of all sensors can achieve the highest accuracy in human activity recognition, as concluded from a comparative analysis for each sensor’s impact on the model’s performance. These results confirm the applicability of the proposed methodology for human awareness purposes in agricultural environments, while the dataset was made publicly available for future research.

Increasing the efficiency of using the SUTB technology in the operation of agricultural units

The article proposes a method for determining the energy parameters of a machine-tractor unit to increase the efficiency of using the SUTB (shifted-up and throttled-back) technology for stepped transmissions of agricultural tractors. The theoretical substantiation of the new method and the results of practical testing in real field conditions are presented.

Novel sensor-based method (quick test) for the in-season rapid evaluation of herbicide efficacy under real field conditions in durum wheat

AbstractOptimum herbicide use is a key factor affecting the success of any integrated weed management strategy. The main objective of the current study was to implement a method based on spectrometer measurements for the in situ evaluation of herbicide efficacy and the detection of potentially herbicide-resistant weeds. Field trials were conducted in Greece between 2018 and 2020 in several durum wheat fields (Triticum durum Desf.). In all trials, the overall effect of herbicide application on the recorded Normalized Difference Vegetation Index (NDVI) values (at 1 and 2 wk after treatment [WAT]) was significant (P ≤ 0.001). For the majority of the surveyed fields, low NDVI values were recorded after 2,4-D application and a mixture of clopyralid + florasulam from 1 WAT, suggesting their increased efficacy. In several cases, the application of pyroxsulam + florasulam resulted in significant NDVI reductions at 2 WAT. As observed at the end of the growing seasons, the herbicides that reduced NDVI resulted in lower weed biomass. Strong correlations were observed between weed aboveground biomass and NDVI (2 WAT). In particular, R2 values were 0.8234 to 0.8649, 0.8453, 0.8595, 0.8149, and 0.8925 for the Aliartos, Thiva, Domokos, Larissa, and Orestiada fields, respectively. The overall effects of herbicide application on wheat grain yield were also significant (P ≤ 0.001). Pot experiments confirmed that the high NDVI values in some cases could be attributed to the presence of herbicide-resistant weeds. For instance, the resistance indices of two accessions of catchweed bedstraw (Galium aparine L.) to mesosulfuron-methyl + iodosulfuron-methyl-sodium ranged between 9.7 and 13.2, whereas one sterile oat [Avena sterilis L. ssp. ludoviciana (Durieu) Gillet &amp; Magne] accession was 8.8 times more resistant to fenoxaprop-p-ethyl than a susceptible one. The present study is targeted at making a significant contribution toward establishing cause–effect relationships and presenting a useful tool for developing more effective weed management practices in more arable crops and under different soil and climatic conditions.

A deep learning approach for anthracnose infected trees classification in walnut orchards

This paper presents a novel approach for the detection of disease-infected leaves on trees with the use of deep learning. Focus of this study was to build an accurate and fast object detection system that can identify anthracnose-infected leaves on walnut trees, in order to be used in real agricultural environments. Similar studies in the literature address the disease identification issue; however, so far, the detection was performed on single leaves which had been removed from trees, using images taken in controlled environment with clear background. A gap has been identified in the detection of infected leaves on tree-level in real-field conditions, an issue which is tackled in our study. Deep learning is an area of machine learning that can be proved particularly useful in the development of such systems. The latest developments in deep learning and object detection, points us towards utilizing and adapting the state-of-the-art single shot detector (SSD) algorithm. An object detector was trained to recognize anthracnose-infected walnut leaves and the trained model was applied to detect diseased trees in a 4 ha commercial walnut orchard. The orchard was initially inspected by domain experts identifying the infected trees to be used as ground truth information. Out of the 379 trees of the orchard, 100 were randomly selected to train the object detector and the remaining 279 trees were used to examine the effectiveness and robustness of the detector comparing the experts’ classification with the predicted classes of the system. The best inputs and hyper-parameter configuration for the trained model provided an average precision of 63% for the object detector, which correctly classified 87% of the validation tree dataset. These encouraging results indicate that the detector shows great potential for direct application in commercial orchards, to detect infected leaves on tree level in real field conditions, and categorize the trees into infected or healthy in real time. Thus, this system can consist an applicable solution for real-time scouting, monitoring, and decision making.

Assessment of the impacts of microbial plant protection products containing Bacillus thuringiensis on the survival of adults and larvae of the honeybee (Apis mellifera)

This study was aimed at evaluating the effect of a microbial pest-controlling product (MPCP) with the active substance Bacillus thuringiensis ssp. aizawai (strain: ABTS-1857) on adults and larvae of honeybees. To determine the contamination levels of Bt spores in different matrices, a colony-feeding study under semi-field conditions was performed. Furthermore, two chronic adult trials and a chronic larval study were conducted under laboratory conditions to test the effects of different concentrations of the plant protection product (PPP) on the development and mortality. Possible modifications of the chronic oral toxicity test were assessed by additional pollen feeding. Our results showed that Bt spores were detected in all matrices over the entire test duration in different concentrations, decreasing over time. The survival of adult bees and larvae was negatively affected in laboratory conditions after a chronic exposure to the MPCP depending on the tested concentrations. Moreover, the earliest sign of bee mortality, resulting from exposure to ABTS-1857, was recorded only after 96 h at the highest tested concentration. Pollen feeding to adults significantly increased the survival of the treated bees. In conclusion, the PPP with the Bt strain ABTS-1857 showed an effect on the mortality of adults and larvae under laboratory conditions. Further studies with Bt-based PPPs under realistic field conditions are necessary to evaluate the potential risk of those MPCPs on honeybees.

Thiourea and hydrogen peroxide priming improved K+ retention and source-sink relationship for mitigating salt stress in rice

Plant bioregulators (PBRs) represent low-cost chemicals for boosting plant defense, especially under stress conditions. In the present study, redox based PBRs such as thiourea (TU; a non-physiological thiol-based ROS scavenger) and hydrogen peroxide (H2O2; a prevalent biological ROS) were assessed for their ability to mitigate NaCl stress in rice variety IR 64. Despite their contrasting redox chemistry, TU or H2O2 supplementation under NaCl [NaCl + TU (NT) or NaCl + H2O2 (NH)] generated a reducing redox environment in planta, which improved the plant growth compared with those of NaCl alone treatment. This was concomitant with better K+ retention and upregulated expression of NaCl defense related genes including HAK21, LEA1, TSPO and EN20 in both NT and NH treated seedlings. Under field conditions, foliar applications of TU and H2O2, at vegetative growth, pre-flowering and grain filling stages, increased growth and yield attributes under both control and NaCl stress conditions. Principal component analysis revealed glutathione reductase dependent reduced ROS accumulation in source (flag leaves) and sucrose synthase mediated sucrose catabolism in sink (developing inflorescence), as the key variables associated with NT and NH mediated effects, respectively. In addition, photosystem-II efficiency, K+ retention and source-sink relationship were also improved in TU and H2O2 treated plants. Taken together, our study highlights that reducing redox environment acts as a central regulator of plant’s tolerance responses to salt stress. In addition, TU and H2O2 are proposed as potential redox-based PBRs for boosting rice productivity under the realistic field conditions.

Experimental investigation of cuttings transport with nanocomposite water-based drilling fluids modified by cellulose nanoparticles

Extended reach (ERD) wells with a horizontal and highly deviated section are commonly utilized in deep oil and natural gas exploration operations. Among many difficulties faced in this complex wellbore trajectory, good hole cleaning is one of the biggest challenges. The main objective of the present study is to investigate the application of cellulose nanoparticles (CNPs) in improving hole cleaning in horizontal drilling operations. Nanocomposite drilling fluids were prepared by adding CNPs, including cellulose nanocrystals (CNCs) and cellulose nanofibers (CNFs), into water-based mud (WBM) at different weight percent concentrations (0.15–0.60 wt%). The flow loop experiments were implemented on a sophisticated purpose-built flow rig by circulating the tested fluid samples into the test section in a horizontal position, considering the influence of drill pipe rotation, flow rates, cuttings sizes, and drill pipe eccentricity. The goal of such variation in the operational parameters is to simulate real field conditions. The cuttings transport ratio (CTR) which is defined as the ratio of the weight of recovered cuttings to the weight of injected cuttings is chosen as the measurement to evaluate hole cleaning. The results revealed that the nanocomposite drilling fluids displayed a considerable enhancement in cuttings removal efficiency, especially with the higher concentration of CNPs. The morphology of CNPs played a vital role in improving the rheological properties of the water-based drilling fluids. In comparison, the drilling fluid samples with CNCs had comparatively lower cuttings transports ratio (CTR) than these of the fluids with CNFs. These differences were connected to their distinguished morphologies and different interactions with bentonite in the fluid system. This work is the first attempt to evaluate the applications of renewable, biodegradable, environmentally friendly, and more cost-effective nanoparticle additives to enhance the capability of drilling fluids in transporting and circulating drilled cuttings out of the wellbore.

Breaking Location of Internal Solitary Waves Over a Sloping Seabed

AbstractWe present a semi‐analytical model for predicting the breaking location of internal solitary waves (ISWs) over a sloping seabed. Our conceptual model is based on laboratory experiments, performed in a wave tank, that reproduce the ISW breaking mechanisms and show how the steepening of the trailing edge leads to verticalization of the wave profile during the shoaling phase. We derive the location of ISWs breaking, that is, the wave verticalization point, through two‐layer, interfacial theoretical models and conservation of wave mass. We apply our model to the case of tidally forced ISWs that are generated in the Strait of Messina (Central Mediterranean Sea), where northward traveling ISWs are expected to refract and break over the frontal slope of Capo Vaticano. Our application is then assessed through numerical investigations, which allow to consider realistic field conditions in terms of water column stratification and geometrical setting. Our results, and the expected ISW‐induced bed shear stress, suggest a link between the predicted breaking locations and the occurrence of sediment resuspension over that specific portion of the slope.

Reliability of animal counts and implications for the interpretation of trends.

Population time series analysis is an integral part of conservation biology in the current context of global changes. To quantify changes in population size, wildlife counts only provide estimates because of various sources of error. When unaccounted for, such errors can obscure important ecological patterns and reduce confidence in the derived trend. In the case of highly gregarious species, which are common in the animal kingdom, the estimation of group size is an important potential bias, which is characterized by high variance among observers. In this context, it is crucial to quantify the impact of observer changes, inherent to population monitoring, on i) the minimum length of population time series required to detect significant trends and ii) the accuracy (bias and precision) of the trend estimate.We acquired group size estimation error data by an experimental protocol where 24 experienced observers conducted counting simulation tests on group sizes. We used this empirical data to simulate observations over 25 years of a declining population distributed over 100 sites. Five scenarios of changes in observer identity over time and sites were tested for each of three simulated trends (true population size evolving according to deterministic models parameterized with declines of 1.1%, 3.9% or 7.4% per year that justify respectively a “declining,” “vulnerable” or “endangered” population under IUCN criteria).We found that under realistic field conditions observers detected the accurate value of the population trend in only 1.3% of the cases. Our results also show that trend estimates are similar if many observers are spatially distributed among the different sites, or if one single observer counts all sites. However, successive changes in observer identity over time lead to a clear decrease in the ability to reliably estimate a given population trend, and an increase in the number of years of monitoring required to adequately detect the trend.Minimizing temporal changes of observers improve the quality of count data and help taking appropriate management decisions and setting conservation priorities. The same occurs when increasing the number of observers spread over 100 sites. If the population surveyed is composed of few sites, then it is preferable to perform the survey by one observer. In this context, it is important to reconsider how we use estimated population trend values and potentially to scale our decisions according to the direction and duration of estimated trends, instead of setting too precise threshold values before action.

Mapping leaf metal content over industrial brownfields using airborne hyperspectral imaging and optimized vegetation indices

Monitoring plant metal uptake is essential for assessing the ecological risks of contaminated sites. While traditional techniques used to achieve this are destructive, Visible Near-Infrared (VNIR) reflectance spectroscopy represents a good alternative to monitor pollution remotely. Based on previous work, this study proposes a methodology for mapping the content of several metals in leaves (Cr, Cu, Ni and Zn) under realistic field conditions and from airborne imaging. For this purpose, the reflectance of Rubus fruticosus L., a pioneer species of industrial brownfields, was linked to leaf metal contents using optimized normalized vegetation indices. High correlations were found between the vegetation indices exploiting pigment-related wavelengths and leaf metal contents (r ≤ − 0.76 for Cr, Cu and Ni, and r ≥ 0.87 for Zn). This allowed predicting the metal contents with good accuracy in the field and on the image, especially Cu and Zn (r ≥ 0.84 and RPD ≥ 2.06). The same indices were applied over the entire study site to map the metal contents at very high spatial resolution. This study demonstrates the potential of remote sensing for assessing metal uptake by plants, opening perspectives of application in risk assessment and phytoextraction monitoring in the context of trace metal pollution.

Analysis of safety regulations for mechanized spraying of agricultural crops

Today, there is a trend of intensive growth of chemical protection of plants by pesticides, potentially hazardous to the environment and humans. Accordingly, the risks of poisoning and occupational diseases associated with the use of pesticides in agricultural production are increasing. In Ukraine, a number of laws and regulations on safety regulations have been adopted to regulate legal relations associated with the use of pesticides in agricultural production. State sanitary rules DSP 8.8.1.2.001-98 are the basic normative document, regulating the requirements to transportation, storage and use of pesticides in production. The standards are being developed and approved for more than a quarter of a century, are out-of-date and do not take into account the peculiarities of new technologies. Therefore, taking into account modern requirements of hygienic rationing and new data on toxicological properties of pesticides, the need to harmonize domestic regulations with the requirements of the European Community is growing. Some existing regulations need revision and modernisation. Recommendations for use of personal protective equipment at spraying are analyzed according to DSP 8.8.1.2.001-98 and the safety data sheet of fungicide Akanto® Plus by DuPont International Operations CH-1218 Le Grand Saconnex/GE. Switzerland, designed in accordance with Regulation (EC) No.1907/2006 as amended. Analysis of safety equipment, namely eye and respiratory protection, showed that application of DSP 8.8.1.2.001-98 recommendations for workers of chemical spraying operations is contradictory, which can create hazardous working conditions. For some types of work it is too high requirements, which are difficult to fulfill in real field conditions. Therefore, in Ukraine, the need arose to revise the current regulations and harmonize them with European standards in terms of safety requirements for transportation, storage and use of pesticides.