Full Cover Research Articles

Landslide Rapid Impact Assessment at Hydro Dam via THyCAS and UAS

The TNB Hydro Catchment Area Surveillance (THyCAS) is a web-based geographic information system (GIS) used to monitor hydropower dam catchment areas in Peninsular Malaysia. It can also be used for landslide rapid impact assessment by monitoring the surrounding landslide area. However, during the rainy season, satellite images are unable to provide the information required by users due to full cloud cover. Therefore, an Unmanned Aircraft System (UAS) is used to provide the data required by THyCAS by mapping the surrounding area affected by landslides and uploading the processed data in THyCAS. Thus, the user can get the required information regarding the landslide incident. Furthermore, with UAS Full Motion Video (FMV) data, the location of the collapsed power transmission towers can be acquired. In addition, any information on land changes that could jeopardise the surrounding dam area is gathered. Therefore, with the information from the rapid impact assessment provided by THyCAS and UAS data, a preliminary risk assessment plan can be established and implemented by the relevant parties. The results obtained from the rapid assessment can also be used as additional information to find out the actual cause of landslides in the area.

Influence of spatiotemporal and meteorological variation on Norwegian atmospheric pollen seasonality

Climate change is and will continue to alter plant responses to their environment. This is especially prominent concerning the adaptive tracking in reproductive phenology. For wind pollinated plants, this will substantially influence their pollen seasonality, yet there are gaps in knowledge about how environmental variation influences pollen seasonality. To investigate this, we monitored daily atmospheric pollen concentrations of seven pollen types from ecologically, economically and allergenically important plants (alder, hazel, willow, birch, pine, grass and mugwort) in twelve Norwegian locations spanning the entire country for up to 28 years. Six daily meteorological variables (maximum temperature, precipitation, wind speed, relative humidity, solar radiation and atmospheric pressure) was obtained from the MET Nordic dataset with full data cover. The pollen seasonality was then modelled using four spatial, three temporal and the six meteorological variables in a generalized linear model approach with a negative binomial distribution to investigate how each variable group thematically and individually contribute to variation in pollen seasonality. We found that the full models explained the most variation, ranging from R2 = 20.3 % to 59.5 %. The models were also highly accurate, being able to predict 54.5 % to 99.1 % of daily pollen concentrations to within 20.1 pollen grains/m3. Overall, the temporal variables were able to explain more variation than spatial and meteorological variables for most pollen types. Month, altitude and maximum temperature were the most important single variables for each category. The importance of each variable could be traced back to their individual effects of reproductive phenology, plant metabolism, species distributions and pollen release processes. We further emphasise the importance of source maps and atmospheric regional transport models in further model improvements. By understanding the relevance of environmental variation to pollen seasonality we can make better predictions regarding the consequences of climate change on plant populations.

Effects of subtle variation in forest canopy openness on cache pilferage and its implications for forest regeneration.

Scatter-hoarding rodents play important roles in plant regeneration and species coexistence in many forest ecosystems. Cache pilferage, the behavior of rodents seeking or relocating seeds cached by other individuals, is ubiquitous during the scatter-hoarding process. The effects of canopy openness on cache pilferage have received considerable attention, most of which have focused on the comparison between full canopy cover and completely open areas, such as forest gaps. However, little attention has been given to whether the subtle variation in forest canopy openness affects cache pilferage, although subtle variation in light environments exists in many forests, especially tropical and subtropical forests, where the overall canopy is large and the forest window is relatively small. Here, we directly tested these questions by simulating 400 artificial caches, each containing one seed from four selected tree species, in a subtropical forest in southwestern China. The overall canopy openness of the forest was relatively small (with a mean value of 11.1%), but subtle spatial variation still existed (ranging from 5.7% to 19.5%). Overall, caches with lower canopy openness were more likely to be pilfered and removed faster, although not all species showed the same pattern. Our study highlights that subtle variation in forest canopy openness, even in a closed primary forest, has significant effects on cache pilferage by rodents, which may influence the following seed germination and forest regeneration processes. Additionally, seedling species composition may further be altered because the canopy effects on cache pilferage are species-specific.

Transitional circulation patterns from full ice cover to ice-off in a seasonally ice-covered lake

There is consensus that under-ice circulation presents multiple phases through the winter, and that different mechanisms dominate each period. In this work, measurements of temperature, water velocity, conductivity, and dissolved oxygen from Lake Massawippi, Quebec, Canada, obtained during the ice-covered season in 2019, were used to characterize the time scales of different winter regimes and transitions among dominating circulation mechanisms. Lake circulation during this period began with a single-cell convection induced by sediment flux pulses in early winter. The single-cell convection decayed into a brief quiescent period. Radiatively driven convection then formed a convectively mixed layer in late winter. The defined mixed layer and temperature structure provided the necessary conditions for the formation of a potential rotational feature, which briefly formed immediately prior to ice break-up. Ice break-up led to complex hydrodynamics that persisted for nearly 28 days following full ice-off. Dissolved oxygen was directly correlated with the varying circulation features throughout the field campaign. This work provides a quantitative measure to delineate the transitions between under-ice regimes and provides novel insights into the subsequent circulation during and after ice break-up.

Experience with the new multi-hole self-expandable metallic stent.

Multi-hole self-expandable metallic stent (M.I.Tech/Boston Scientific: MHSEMS) has small holes in the cover part of FCSEMS and has properties between UCSEMS and FCSEMS. The MHSEMS was originally an FCSEMS with holes in all cells. In the distal bile duct, the MHSEMS have the potential to prevent migration by allowing tissue to enter the small holes. In the hilar region, the MHSEMS can potentially prolong the duration of patency of the central bile duct by preventing ingrowth by covering the branches without impeding them. However, because there were reports of cases of inoperable removal due to ingrowth overseas, the model launched in Japan in 2022 had fewer holes, and the cover of the Hanarostent Biliary Full Cover NEO (M.I. Tech/Boston Scientific) had a row of holes in every other row. It was used in 7 cases of malignant biliary obstruction. The primary diseases were gallbladder cancer, cholangiocarcinoma, and pancreatic cancer. The obstruction sites were the hilar region and the distal bile duct. All patients underwent successful implantation with no pancreatitis or cholangitis observed. Five patients continued chemotherapy. One gallbladder cancer patient died after 20 days, one cholangiocarcinoma patient experienced obstruction after 81 days, and the other five cases showed no evidence of obstruction or deviation (ranging from 6 to 119 days after implantation, with an average of 75 days). MHSEMS can be used for malignant biliary obstruction, mainly in the distal bile duct.

Endoscopic Treatment of Malignant Hilar Biliary Obstruction.

Stent implantation is an effective approach for palliative treatment of Bismuth-Corlette type III-IV malignant hilar biliary obstructions (MHBOs). In this article, we reviewed the currently used access methods for biliary stent placement (percutaneous transhepatic biliary drainage, endoscopic biliary drainage, endosonography guided biliary drainage), the available stent types (plastic stent, self-expanding metallic stent, full cover self-expanding metallic stent, radioactive self-expanding metallic stent), major approaches (unilateral, bilateral) and deployment methods (stent-in-stent, stent-by-stent). Finally, this review gives an outlook on perspectives of development in stenting and other palliative methods in MHBO.

Reducing Aerodynamic Drag on Flatbed Trailers for Passenger Vehicles Using Novel Appendable Devices

This article presents a study on the aerodynamic drag of a generic dual-axle flatbed trailer and explores ways to reduce the drag using appendable drag-reducing devices. The primary sources of drag originated from the van and trailer’s rear, along with the trailer’s wheels. The most-effective initial device for reducing drag was a full trailer underside cover, which offered a 7% drag reduction. Additionally, ladder racks, dropsides, and rear gates were studied, and it was found that protruding ladder racks significantly increased drag. Rear gates added large amounts of drag and should be removed and stored when not needed. The study also explored novel mid-section devices that increased the van’s base pressure and reduced drag. An axle test revealed that drag for single-, dual-, and triple-axle trailers was very similar in direct flow, but different in yawed flow. A drawbar length test showed a near-linear relationship between drawbar length and drag, manifesting as a 1.7% change in drag per 250 mm change in drawbar length. Several novel modifications were made to the trailer, including fitting six unique appendable devices, which offered a total 7.3% drag reduction. A novel rear van device known as the multi-stage converging cavity was introduced, which reduced drag by nearly 18%. When all the devices were used together, a total 25% drag reduction was observed for the van–trailer combination.

Design of Variable Stiffness Trajectories with Cubic Ferguson Curve.

To design a class of full cover trajectories that satisfy curvature limitations and enhance the buckling load of constructed laminates, a variable stiffness laminate is proposed by applying the cubic Ferguson curve. First, the traditional explicit form of the cubic Ferguson curve is redefined as polar coordinates, two connected Ferguson curve segments with three extra parameters are applied to describe full cover trajectories, and the effects on trajectories introduced by these modifications are discussed. Then, the finite element method is used to introduce parameters for analyzing the buckling load of the designed variable stiffness laminates. Numerical experiments show that automatic fiber placement (AFP) trajectories described by the cubic Ferguson curve can automatically reach C1 continuity and can be locally modified by adjusting the introduced parameters. Compared with traditional constant stiffness laminates, the variable stiffness laminates designed using the proposed method exhibit a higher buckling load and better stability.

Investigation of some factors affecting habitat selection and nest size of Formica rufa

The study aimed to assess the habitat preferences and nest volumes of Formica rufa in coniferous stands, taking into account various stand, topographic, and climatic variables. The variables that impact the habitat of F. rufa in the Western Black Sea region were identified through the utilization of climate data, stand map, DEM data, and field data. Ten different variables were analyzed separately for F. rufa nests using the Geographic Information System (GIS). Based on the stand variables, it can be inferred that F. rufa were predominantly preferred as over-mature, full canopy cover, medium and poor site class, and productive stands. Based on the analysis of topographical variables, the ants exhibit a preference for areas that have low slopes, high elevations, and shady aspects. Additionally, the investigation of climatic variables revealed a higher incidence of ants in regions with an average temperature below 12 °C, and low levels of precipitation. It was determined that nest volumes are larger in high site index, productive stands, young stands, low crown closure stands and high elevation. Based on the findings, it is crucial to monitor the habitat preferences of F. rufa over extended periods and large geographical areas. The protection and enhancement of their habitats are imperative for the sustainability and health of the ecosystem.

Use of Landsat Satellite Images in the Assessment of the Variability in Ice Cover on Polish Lakes

Despite several decades of observations of ice cover in Polish lakes, researchers have not broadly applied satellite images to date. This paper presents a temporal and spatial analysis of the variability in the occurrence of ice cover on lakes in the Drawskie Lakeland in the hydrological years 1984–2022 based on satellite data from Landsat missions 4, 5, 7, 8, and 9. The range of occurrence of ice cover was determined based on the value of the Normalised Difference Snow Index (NDSI) and blue spectral band (ρλblue). The determination of ice cover extent adopted ρλblue values from 0.033 to 0.120 as the threshold values. The analysis covered 67 lakes with an area from 0.07 to 18.71 km2. A total of 53 images were analysed, 14 and 39 out of which showed full and partial ice cover, respectively. The cluster analysis permitted the designation of two groups of lakes characterised by an approximate range of ice cover. The obtained results were analysed in the context of the morphometric parameters of the lakes. It was evidenced that the range of the ice cover on lakes is determined by the surface area of the lakes; their mean and maximum depth, volume, length, and width; and the height of the location above sea level. The results of analyses of the spatial range of ice cover in subsequent scenes allowed for the preparation of maps of probability of ice cover occurrence that permit the complete determination of its variability within each of the lakes. Monitoring of the spatial variability in ice cover within individual lakes as well as in reference to lakes not subject to traditional observations offers new research possibilities in many scientific disciplines focused on these ecosystems.

Operator Intracranial Dose Protection During Fluoroscopic-Guided Interventions.

We utilized an anthropomorphic model made with a human skull to determine how different personal protective equipment influence operator intracranial radiation absorbed dose. A custom anthropomorphic phantom made with a human skull coated with polyurethane rubber, mimicking superficial tissues, and was mounted onto a plastic thorax. To simulate scatter, an acrylic plastic scatter phantom was placed onto the fluoroscopic table with a 1.5mm lead apron on top. Two Radcal radiation detectors were utilized; one inside of the skull and a second outside. Fluoroscopic exposures were performed with and without radiation protective equipment in AP, 45-degree RAO, and 45-degree LAO projections. The skull and soft tissues reduce intracranial radiation by 76% when compared to radiation outside the skull. LAO (308.95 μSv/min) and RAO projections (96.47μSv/min) result in significantly higher radiation exposure to the primary operator when compared to an AP projection (54 μSv/min). All tested radiation protection equipment demonstrated various reduction in intracranial radiation when compared to no protection. The hood (68% reduction in AP, 91% LAO, and 43% in RAO), full cover (53% reduction in AP, 76% in LAO, and 54% in RAO), and open top with ear coverage (43% reduction in AP, 77% reduction in LAO, and 22% in RAO) demonstrated the most reduction in intracranial radiation when compared to the control. All tested equipment provided various degrees of additional intracranial protection. The skull and soft tissues attenuate a portion of intracranial radiation.

A randomised controlled trial of compression therapies for the treatment of venous leg ulcers (VenUS 6): study protocol for a pragmatic, multicentre, parallel-group, three-arm randomised controlled trial

BackgroundVenous leg ulcer(s) are common, recurring, open wounds on the lower leg, resulting from diseased or damaged leg veins impairing blood flow. Wound healing is the primary treatment aim for venous leg ulceration, alongside the management of pain, wound exudate and infection.Full (high) compression therapy delivering 40 mmHg of pressure at the ankle is the recommended first-line treatment for venous leg ulcers. There are several different forms of compression therapy available including wraps, two-layer hosiery, and two-layer or four-layer bandages.There is good evidence for the clinical and cost-effectiveness of four-layer bandage and two-layer hosiery but more limited evidence for other treatments (two-layer bandage and compression wraps). Robust evidence is required to compare clinical and cost-effectiveness of these and to investigate which is the best compression treatment for reducing time to healing of venous leg ulcers whilst offering value for money. VenUS 6 will therefore investigate the clinical and cost-effectiveness of evidence-based compression, two-layer bandage and compression wraps for time to healing of venous leg ulcers.MethodsVenUS 6 is a pragmatic, multi-centre, three-arm, parallel-group, randomised controlled trial. Adult patients with a venous leg ulcer will be randomised to receive (1) compression wraps, (2) two-layer bandage or (3) evidence-based compression (two-layer hosiery or four-layer bandage).Participants will be followed up for between 4 and 12 months. The primary outcome will be time to healing (full epithelial cover in the absence of a scab) in days since randomisation. Secondary outcomes will include key clinical events (e.g. healing of the reference leg, ulcer recurrence, ulcer/skin deterioration, amputation, admission/discharge, surgery to close/remove incompetent superficial veins, infection or death), treatment changes, adherence and ease of use, ulcer related pain, health-related quality of life and resource use.DiscussionVenUS 6 will provide robust evidence on the clinical and cost-effectiveness of the different forms of compression therapies for venous leg ulceration.VenUS 6 opened to recruitment in January 2021 and is currently recruiting across 30 participating centres.Trial registrationISRCTN67321719. Prospectively registered on 14 September 2020

Nunataryuk field campaigns: understanding the origin and fate of terrestrial organic matter in the coastal waters of the Mackenzie Delta region

Abstract. Climate warming and related drivers of soil thermal change in the Arctic are expected to modify the distribution and dynamics of carbon contained in perennially frozen grounds. Thawing of permafrost in the Mackenzie River watershed of northwestern Canada, coupled with increases in river discharge and coastal erosion, triggers the release of terrestrial organic matter (OMt) from the largest Arctic drainage basin in North America into the Arctic Ocean. While this process is ongoing and its rate is accelerating, the fate of the newly mobilized organic matter as it transits from the watershed through the delta and into the marine system remains poorly understood. In the framework of the European Horizon 2020 Nunataryuk programme, and as part of the Work Package 4 (WP4) Coastal Waters theme, four field expeditions were conducted in the Mackenzie Delta region and southern Beaufort Sea from April to September 2019. The temporal sampling design allowed the survey of ambient conditions in the coastal waters under full ice cover prior to the spring freshet, during ice breakup in summer, and anterior to the freeze-up period in fall. To capture the fluvial–marine transition zone, and with distinct challenges related to shallow waters and changing seasonal and meteorological conditions, the field sampling was conducted in close partnership with members of the communities of Aklavik, Inuvik and Tuktoyaktuk, using several platforms, namely helicopters, snowmobiles, and small boats. Water column profiles of physical and optical variables were measured in situ, while surface water, groundwater, and sediment samples were collected and preserved for the determination of the composition and sources of OMt, including particulate and dissolved organic carbon (POC and DOC), and colored dissolved organic matter (CDOM), as well as a suite of physical, chemical, and biological variables. Here we present an overview of the standardized datasets, including hydrographic profiles, remote sensing reflectance, temperature and salinity, particle absorption, nutrients, dissolved organic carbon, particulate organic carbon, particulate organic nitrogen, CDOM absorption, fluorescent dissolved organic matter intensity, suspended particulate matter, total particulate carbon, total particulate nitrogen, stable water isotopes, radon in water, bacterial abundance, and a string of phytoplankton pigments including total chlorophyll. Datasets and related metadata can be found in Juhls et al. (2021) (https://doi.org/10.1594/PANGAEA.937587).

Design and Implementation of a Low-Voltage Photovoltaic System Integrated with Battery Energy Storage

In this paper, the simulation and design of a power converter suitable for a low-voltage photovoltaic (PV) battery energy storage converter was investigated. The converter was suitable for sources and loads with near voltage levels and were aimed at efficiency improvement. The converter was called a series partial power converter (SPPC). A continuous current and a boost SPPC topology based on an isolated Cûk converter was constructed. The operation modes of the converter were analyzed. The efficiency verification test of the SPPC in a laboratory environment was completed using an outdoor start-up test, a photovoltaic full cover test and a steady-state operation test under different power levels. The results show that the SPPC can achieve 95–98% converter efficiency within the 87 W–242 W power range. The incremental conductance method based on the SPPC can realize the dynamic MPPT under constant illumination and changing meteorological conditions.

Improving 3-PG calibration and parameterization using artificial neural networks

Understanding how the physiological processes of trees are affected by the environment or silvicultural practices is important for forest management, which requires process-based models. It enables the evaluation of the growth of a forest under different scenarios. The 3-PG model has been widely used all over the world, justified by its simplicity and efficiency, as it uses a more accessible language and fewer parameters than other process-based models. It is a model of greatest interest for forest management because it enables the use of allometric equations to calculate variables of interest in this area, such as the average diameter at 1.30 m height (DBH), total height and stand volume. The 3-PG parameterization is essential to guarantee the model's good performance; however, in some cases, when observed data are not available, values from the literature is used or calibration is performed. In general, there is a mixture of these alternatives in the same parameterization, but some of the parameters generate greater sensitivity in some outputs or change according to site characteristics. In the present work, we analyzed the efficiency of artificial neural networks to predict some of the parameters pointed out in the literature as being of the greatest importance for 3-PG using climate and process variables as inputs. For this, a simulated database was generated, using 16 parameterizations of 3-PG, for different regions of Brazil. The parameters values of the DBH function (as and ns), minimum and maximum fraction of biomass allocated to the root (ηRn and ηRx), and age at full canopy cover (tc) were associated with this database. The Artificial Neural Networks (ANNs) were trained using the database with parameter repetition over time and with the average condition of each site. In the second case, training was performed using 100% of the data, and validation was performed using a simulated database. The efficiency of neural networks has been proven in predicting the parameters as, ns and ηRx, with validation root mean squared error (RMSE) of 6.9%, 6.9% and 4.8%, in the first training approach, respectively. For training based on sites average condition RMSE was 20.7%, 3.0% and 8.8%, for as, ns and ηRx, respectively. The study showed the need for more scientific investigation for the other parameters, including information and input variables such as soil characteristics. As demonstrated in this study, the possibility of parameterizing 3-PG with ANNs or any machine learning technique may contribute to the broader use of this process-based model. In addition, artificial neural networks have great potential to assist in the calibration process of the 3-PG model, making this process more efficient by integrating environmental conditions and allowing the association between parameters. It is recommended to apply these ANNs for the conditions tested here.

Accounting for the aerosol type and additional satellite-borne aerosol products improves the prediction of PM2.5 concentrations

Fine airborne particles (diameter <2.5 μm; PM2.5) are recognized as a major threat to human health due to their physicochemical properties: composition, size, shape, etc. However, normally only size-fraction-specific particle concentrations are monitored. Interestingly, although the aerosol type is reported as part of the aerosol optical depth retrieval from satellite observations, it has not been utilized, to date, as an auxiliary information/co-variate for PM2.5 prediction. We developed Random Forest (RF) and eXtreme Gradient Boosting (XGBoost) models that account for this information when predicting surface PM2.5. The models take as input only widely available data: satellite aerosol products with full cover and surface meteorological data. Distinct models were developed for AOD of specific aerosol types. Both the RF and XGBoost models performed well, showing moderate-to-high cross-validated adjusted R2 (RF: 0.753–0.909; XGBoost: 0.741–0.903), depending on the aerosol type and other covariates. The weighted performance of the specific aerosol-type models was higher than of the RF and XGBoost baseline models, where all the AOD retrievals were used together (the common practice). Our approach can provide improved risk estimates due to exposure to PM2.5, better resolved radiative forcing calculations, and tailored abatement surveillance of specific pollutants/sources.

Irrigation of protected pepper crops according to growth stage using dynamic evapotranspiration estimates increases the water use efficiency

Current knowledge on crop irrigation in greenhouses is limited, and most irrigation measures are based on evapotranspiration (ET) estimated using external climatic conditions. Moreover, crop water requirement estimation by the Penman-Monteith (PM) model assumes complete coverage of the soil by the plants and usually does not account for partial cover, which changes during the growth of annual crops. The main goals of the present research were: (i) to develop and apply irrigation demand estimates for greenhouse pepper crops during their growth, based on internal meteorological conditions and real-time plant characteristics; and (ii) to examine the effect of that irrigation on yield. Experiments were conducted during two consecutive seasons in greenhouse pepper crops in the Jordan Valley region of eastern Israel. Four irrigation treatments were applied based on four different ET models: (i) PM model for outside reference evapotranspiration based on the FAO56 methodology, also denoted as the commercial treatment; (ii) PMrb model for pepper plants, which is a standard PM model in which a boundary layer resistance replaces the aerodynamic resistance; (iii) Shuttleworth-Wallace Layer (SWL) model which considers the soil and plants as separate interactive layers; (iv) Shuttleworth-Wallace Patch (SWP) model which considers the soil and plants as independent patches. The commercial treatment used external climatic conditions from a nearby meteorological station, whereas the other three treatments used internal meteorological conditions measured inside the greenhouse. Results showed a high correlation (R2 > 0.88) between leaf area index, vegetation cover fraction, and plant height during plant growth. Using the same meteorological conditions inside the greenhouse, the seasonal ET estimated by the PMrb model, which considers full vegetation cover, was larger by 21-28% than the SWL and SWP models, which consider the partial plant cover. Irrigation doses were deduced from ET multiplied by crop coefficients derived in a previous study for the same crop and structures. Using average data of the two seasons, we found that seasonal irrigation based on the two SW models was lower by 5-15% than that based on PMrb, and by 35-42% than the commercial irrigation. The water use efficiency of the commercial treatment was the lowest, while for the other treatments it was about 0.02 ton m-3 and higher by about 40% than the commercial. We conclude that irrigation of annual crops based on partitioning ET into evaporation and transpiration based on crop coverage and using internal climatic conditions allows water-savings without significant yield loss.

Cover crops and a devigorating rootstock can impart substantial agroecosystem services to high-resource vineyards: A multi-year study

In vineyards, cover crops typically grow concurrently with grapevines and can impart a multitude of agroecosystem services; yet concerns over potential disservices might limit adoption. Reductions in yield and vegetative growth are key disservices of concern, but at sites with high soil resources, reducing excessive vegetative growth is often considered beneficial, if the yield is not strongly penalized. To optimize agroecosystem services provided by cover crops, it is crucial to examine above- and belowground plant responses over multiple years. Documentation of the responses of fruit crop root systems to cover crops may clarify potential benefits for long-term agroecosystem services associated with aboveground growth and soil resources. In 2016, we established a perennial grass under young vines (full floor cover) to examine if agroecosystem services imparted by an under-vine cover crop change in the first five years of vineyard production and depend on rootstock vigor. Overall, cover crop reduced grapevine vegetative growth between 13% and 30% across all years and with a trend of more substantial reductions in the first two years. In contrast, yield was reduced in only three of the five years, between 9% and 25%, depending on the rootstock. Furthermore, neither cover crop nor differences in rootstock vigor resulted in relevant or consistent changes in fruit chemistry during the study. Overall, we found that in a relatively fertile, young vineyard, combining a lower vigor rootstock with a perennial, under-vine cover crop imparts substantial agroecosystem services in comparison to the more common practices of using a medium vigor rootstock and spraying herbicide under the vines. These services included improved crop load (ratio of fruit to vegetative mass), increased soil phosphorus availability, increased deep soil water content, and presumably lower labor and other costs associated with vineyard maintenance. Studies on a decadal timescale are needed to further clarify whether these services persist, accumulate with time, or if competition from the cover crop eventually leads to unacceptable decreases in vine nutrient status, growth, and production.

Integration effect of vetiver grass strips with maize population density on soil erosion under two contrasting slopes of rainforest agroecology

Water erosion is a global concern that threatens sustainable agriculture. Using vetiver grass strip (VGS) and maize population density (MPD) separately to control soil erosion has been documented. Complementing VGS with high MPD could enhance crop yield and erosion control efficiency on sloping lands but there is no quantitative study on the combined effects of VGS with MPD on soil nutrient erosion globally. Thus, a 2-year field experiment was conducted to assess the effectiveness of VGS + MPD in controlling soil nutrient erosion and improving maize yields on two contrasting slopes under rainforest agroecology. Five treatments [VGS established at 5 m intervals with MPD of 40,000 stands ha−1 (VGS5 + MPD40); VGS established at 5 m intervals with MPD of 53,333 stands ha−1 (VGS5 + MPD53); VGS established at 10 intervals with MPD of 40,000 stands ha−1 (VGS10 + MPD40); VGS established at 10 intervals with MPD of 53,333 stands ha−1 (VGS10 + MPD53) and plot planted to MPD of 53,333 stands ha−1 only serves as control (MPD53)] were imposed on 5 % and 10 % slopes. Runoff was higher in control (MPD53) than other treatments by a range of 92.2 % to 73.8 % on a 5 % slope and 73.3 % to 52.2 % on a 10 % slope. Similarly, the relative reductions in soil loss compared to the control ranged from 89.9 % to 70.2 % on a 5 % slope and 90.8 % to 84.2 % on a 10 % slope. Amongst treatments, VGS5 + MPD53 had the lowest nutrient volume discharge on both slopes due to complimentary impacts of higher MPD to provide a full vegetation cover to prevent splash erosion while closely spaced VGS helps to trap transportable fine particles down the slope. Runoff and soil loss from the 10 % slope exceeded the 5 % slope by 61.2 % and 77.4 % respectively. Average maize yields for VGS5 + MPD53 on both slopes were significantly (p ≤ 0.05) higher than other treatments and maize yield on the 5 % slope exceeded the 10 % slope by 30.9 %. Slope gradient is a major driving force for water erosion and integration of VGS5 with MPD53 is the most effective in controlling soil nutrient erosion and improving maize yield on 5–10 % slopes under rainforest agroecology.

Remote sensing-based evapotranspiration modeling using geeSEBAL for sugarcane irrigation management in Brazil

Irrigated agriculture requires the implementation of innovative tools to improve irrigation water management and accurate estimation of actual evapotranspiration (ETa) such as remote sensing-based methodology. This study aimed to evaluate the irrigation management and estimating evapotranspiration through the geeSEBAL, a new tool for automated estimation of ETa based on the Surface Energy Balance Algorithm for Land (SEBAL) and a simplified version of the Calibration using Inverse Modeling at Extreme Conditions (CIMEC) process for the endmembers selection, implemented into the Google Earth Engine (GEE) environment. GeeSEBAL has not been used yet in Brazil for irrigation proposes, and in this research, it was applied to estimate ETa using Landsat images and ERA5-Land as meteorological inputs in the largest sugarcane producing region of the world in Brazil for two ratoon seasons by comparing daily ETa with values obtained from eddy covariance (EC) data, Energy balance components using geeSEBAL were consistent with the measured data and daily ETa presenting RMSE of 0.46 mm with R2 = 0.97. Modeled ETa and Kc were similar for the two seasons, although somewhat overestimated for the fifth ratoon when compared to the EC data, mainly during high atmospheric demand (crop mid-stage). Still, the Kc values were similar to the standard values available in the literature and measured flux tower data for the two ratoons seasons. With ETa from geeSEBAL it was possible to identify water stress over the growing seasons using the remote sensing-based soil water balance, which occurred mainly during the phase after the crop reached the peak Kc (full cover stage) when the irrigation depth required was very high. This analysis showed that geeSEBAL has a significant potential for assessment of ETa for irrigation monitoring and management, even in missing climate data areas, allowing important advances in water resources management for sugarcane and other irrigated crops at field or regional scales.