scholarly journals Hyperspectral Reflectance of Light-Adapted Leaves Can Predict Both Dark- and Light-Adapted Chl Fluorescence Parameters, and the Effects of Chronic Ozone Exposure on Date Palm (Phoenix dactylifera)

2020 ◽  
Vol 21 (17) ◽  
pp. 6441 ◽  
Author(s):  
Lorenzo Cotrozzi ◽  
Giacomo Lorenzini ◽  
Cristina Nali ◽  
Elisa Pellegrini ◽  
Vincenzo Saponaro ◽  
...  
Keyword(s):  
Precision Agriculture ◽  
Large Scale ◽  
Goodness Of Fit ◽  
Date Palm ◽  
Full Range ◽  
Ambient Air ◽  
Hyperspectral Data ◽  
Ozone Exposure ◽  
Plant Phenotyping ◽  
Spectral Models

High-throughput and large-scale measurements of chlorophyll a fluorescence (ChlF) are of great interest to investigate the photosynthetic performance of plants in the field. Here, we tested the capability to rapidly, precisely, and simultaneously estimate the number of pulse-amplitude-modulation ChlF parameters commonly calculated from both dark- and light-adapted leaves (an operation which usually takes tens of minutes) from the reflectance of hyperspectral data collected on light-adapted leaves of date palm seedlings chronically exposed in a FACE facility to three ozone (O3) concentrations (ambient air, AA; target 1.5 × AA O3, named as moderate O3, MO; target 2 × AA O3, named as elevated O3, EO) for 75 consecutive days. Leaf spectral measurements were paired with reference measurements of ChlF, and predictive spectral models were constructed using partial least squares regression. Most of the ChlF parameters were well predicted by spectroscopic models (average model goodness-of-fit for validation, R2: 0.53–0.82). Furthermore, comparing the full-range spectral profiles (i.e., 400–2400 nm), it was possible to distinguish with high accuracy (81% of success) plants exposed to the different O3 concentrations, especially those exposed to EO from those exposed to MO and AA. This was possible even in the absence of visible foliar injury and using a moderately O3-susceptible species like the date palm. The latter view is confirmed by the few variations of the ChlF parameters, that occurred only under EO. The results of the current study could be applied in several scientific fields, such as precision agriculture and plant phenotyping.

scholarly journals Hyperspectral Detection and Monitoring of Salt Stress in Pomegranate Cultivars

Agronomy ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1038
Author(s):  
Antonella Calzone ◽  
Lorenzo Cotrozzi ◽  
Giacomo Lorenzini ◽  
Cristina Nali ◽  
Elisa Pellegrini
Keyword(s):  
Salt Stress ◽  
Precision Agriculture ◽  
Goodness Of Fit ◽  
Management Practices ◽  
Plant Phenotyping ◽  
Plant Responses ◽  
Least Squares Regression ◽  
Spectral Signatures ◽  
Nursery Management ◽  
Leaf Parameters

Advancements in the ability to detect plant responses to salinity are mandatory to improve crop yield, quality, and management practices. The present study shows the capability of hyperspectral reflectance (400–2400 nm) to rapidly and non-destructively detect and monitor the responses of two pomegranate cultivars (Parfianka, P, and Wonderful, W) under salt treatment (i.e., 200 mL of 100 mM NaCl solution every day) for 35 days. Analyzing spectral signatures from asymptomatic leaves, the two cultivars, as well as salinity conditions were discriminated. Furthermore, using a partial least squares regression approach, we constructed predictive models to concomitantly estimate (goodness-of-fit model, R2: 0.61–0.79; percentage of the root mean square error over the data range, %RMSE: 9–14) from spectra of various physiological leaf parameters commonly investigated in plant/salinity studies. The analyses of spectral signatures enabled the early detection of salt stress (i.e., from 14 days from the beginning of treatment, FBT), even in the absence of visible symptoms, but they did not allow the identification of the different degrees of salt tolerance between cultivars; this cultivar-specific tolerance to salt was instead reported by analyzing variations of leaf parameters estimated from spectra (W was less tolerant than P), which, in turn, allowed the detection of salt stress only at later times of analysis (i.e., slightly from 21 day FBT and, evidently, at the end of treatment). The proposed approach could be used in precision agriculture, high-throughput plant phenotyping, and smart nursery management to enhance crop quality and yield.

scholarly journals Early Detection of Sage (Salvia officinalis L.) Responses to Ozone Using Reflectance Spectroscopy

Plants ◽  
2019 ◽  
Vol 8 (9) ◽  
pp. 346 ◽  
Author(s):  
Marchica ◽  
Loré ◽  
Cotrozzi ◽  
Lorenzini ◽  
Nali ◽  
...  
Keyword(s):  
Goodness Of Fit ◽  
Full Range ◽  
Vegetation Indices ◽  
Leaf Traits ◽  
Reflectance Spectroscopy ◽  
Least Squares Regression ◽  
Spectral Models ◽  
Spectral Profiles ◽  
Salvia Officinalis L ◽  
The Impact

Advancements in techniques to rapidly and non-destructively detect the impact of tropospheric ozone (O3) on crops are required. This study demonstrates the capability of full-range (350–2500 nm) reflectance spectroscopy to characterize responses of asymptomatic sage leaves under an acute O3 exposure (200 ppb for 5 h). Using partial least squares regression, spectral models were developed for the estimation of several traits related to photosynthesis, the oxidative pressure induced by O3, and the antioxidant mechanisms adopted by plants to cope with the pollutant. Physiological traits were well predicted by spectroscopic models (average model goodness-of-fit for validation (R2): 0.65–0.90), whereas lower prediction performances were found for biochemical traits (R2: 0.42–0.71). Furthermore, even in the absence of visible symptoms, comparing the full-range spectral profiles, it was possible to distinguish with accuracy plants exposed to charcoal-filtered air from those exposed to O3. An O3 effect on sage spectra was detectable from 1 to 5 h from the beginning of the exposure, but ozonated plants quickly recovered after the fumigation. This O3-tolerance was confirmed by trends of vegetation indices and leaf traits derived from spectra, further highlighting the capability of reflectance spectroscopy to early detect the responses of crops to O3.

scholarly journals Precision Agriculture for Resource Use Efficiency in Smallholder Farming Systems in Sub-Saharan Africa: A Systematic Review

2021 ◽  
Vol 13 (3) ◽  
pp. 1158
Author(s):  
Cecilia M. Onyango ◽  
Justine M. Nyaga ◽  
Johanna Wetterlind ◽  
Mats Söderström ◽  
Kristin Piikki
Keyword(s):  
Resource Use ◽  
Precision Agriculture ◽  
Large Scale ◽  
English Language ◽  
Management Practices ◽  
Smallholder Farmers ◽  
Management Strategies ◽  
Sub Saharan Africa ◽  
Smallholder Farming ◽  
Sub Saharan

Opportunities exist for adoption of precision agriculture technologies in all parts of the world. The form of precision agriculture may vary from region to region depending on technologies available, knowledge levels and mindsets. The current review examined research articles in the English language on precision agriculture practices for increased productivity among smallholder farmers in Sub-Saharan Africa. A total of 7715 articles were retrieved and after screening 128 were reviewed. The results indicate that a number of precision agriculture technologies have been tested under SSA conditions and show promising results. The most promising precision agriculture technologies identified were the use of soil and plant sensors for nutrient and water management, as well as use of satellite imagery, GIS and crop-soil simulation models for site-specific management. These technologies have been shown to be crucial in attainment of appropriate management strategies in terms of efficiency and effectiveness of resource use in SSA. These technologies are important in supporting sustainable agricultural development. Most of these technologies are, however, at the experimental stage, with only South Africa having applied them mainly in large-scale commercial farms. It is concluded that increased precision in input and management practices among SSA smallholder farmers can significantly improve productivity even without extra use of inputs.

scholarly journals Characterization of Pharmaceutical Tablets Using UV Hyperspectral Imaging as a Rapid Line to Line Analysis Tool

Sensors ◽  
2021 ◽  
Vol 21 (13) ◽  
pp. 4436
Author(s):  
Mohammad Al Ktash ◽  
Mona Stefanakis ◽  
Barbara Boldrini ◽  
Edwin Ostertag ◽  
Marc Brecht
Keyword(s):  
Hyperspectral Imaging ◽  
Large Scale ◽  
Solid Phase ◽  
Ultra Violet ◽  
Principal Component ◽  
Ccd Camera ◽  
Conveyor Belt ◽  
Hyperspectral Data ◽  
Analysis Tool ◽  
Sample Set

A laboratory prototype for hyperspectral imaging in ultra-violet (UV) region from 225 to 400 nm was developed and used to rapidly characterize active pharmaceutical ingredients (API) in tablets. The APIs are ibuprofen (IBU), acetylsalicylic acid (ASA) and paracetamol (PAR). Two sample sets were used for a comparison purpose. Sample set one comprises tablets of 100% API and sample set two consists of commercially available painkiller tablets. Reference measurements were performed on the pure APIs in liquid solutions (transmission) and in solid phase (reflection) using a commercial UV spectrometer. The spectroscopic part of the prototype is based on a pushbroom imager that contains a spectrograph and charge-coupled device (CCD) camera. The tablets were scanned on a conveyor belt that is positioned inside a tunnel made of polytetrafluoroethylene (PTFE) in order to increase the homogeneity of illumination at the sample position. Principal component analysis (PCA) was used to differentiate the hyperspectral data of the drug samples. The first two PCs are sufficient to completely separate all samples. The rugged design of the prototype opens new possibilities for further development of this technique towards real large-scale application.

scholarly journals Nondestructive estimation of potato yield using relative variables derived from multi-period LAI and hyperspectral data based on weighted growth stage

Plant Methods ◽  
2020 ◽  
Vol 16 (1) ◽  
Author(s):  
Shanjun Luo ◽  
Yingbin He ◽  
Qian Li ◽  
Weihua Jiao ◽  
Yaqiu Zhu ◽  
...  
Keyword(s):  
Precision Agriculture ◽  
Growth Stage ◽  
Estimation Error ◽  
Potato Yield ◽  
Hyperspectral Data ◽  
Single Stage ◽  
Accurate Estimation ◽  
Yield Estimation ◽  
Area Index ◽  
Red Edge

Abstract Background The accurate estimation of potato yield at regional scales is crucial for food security, precision agriculture, and agricultural sustainable development. Methods In this study, we developed a new method using multi-period relative vegetation indices (rVIs) and relative leaf area index (rLAI) data to improve the accuracy of potato yield estimation based on the weighted growth stage. Two experiments of field and greenhouse (water and nitrogen fertilizer experiments) in 2018 were performed to obtain the spectra and LAI data of the whole growth stage of potato. Then the weighted growth stage was determined by three weighting methods (improved analytic hierarchy process method, IAHP; entropy weight method, EW; and optimal combination weighting method, OCW) and the Slogistic model. A comparison of the estimation performance of rVI-based and rLAI-based models with a single and weighted stage was completed. Results The results showed that among the six test rVIs, the relative red edge chlorophyll index (rCIred edge) was the optimal index of the single-stage estimation models with the correlation with potato yield. The most suitable single stage for potato yield estimation was the tuber expansion stage. For weighted growth stage models, the OCW-LAI model was determined as the best one to accurately predict the potato yield with an adjusted R2 value of 0.8333, and the estimation error about 8%. Conclusion This study emphasizes the importance of inconsistent contributions of multi-period or different types of data to the results when they are used together, and the weights need to be considered.

scholarly journals Evapotranspiration Estimation with Small UAVs in Precision Agriculture

Sensors ◽  
2020 ◽  
Vol 20 (22) ◽  
pp. 6427
Author(s):  
Haoyu Niu ◽  
Derek Hollenbeck ◽  
Tiebiao Zhao ◽  
Dong Wang ◽  
YangQuan Chen
Keyword(s):  
Energy Balance ◽  
High Resolution ◽  
Spatial Resolution ◽  
Precision Agriculture ◽  
Large Scale ◽  
Bowen Ratio ◽  
Future Research ◽  
Accurate Estimation ◽  
Research Areas ◽  
Energy Balance Approach

Estimating evapotranspiration (ET) has been one of the most critical research areas in agriculture because of water scarcity, the growing population, and climate change. The accurate estimation and mapping of ET are necessary for crop water management. Traditionally, researchers use water balance, soil moisture, weighing lysimeters, or an energy balance approach, such as Bowen ratio or eddy covariance towers to estimate ET. However, these ET methods are point-specific or area-weighted measurements and cannot be extended to a large scale. With the advent of satellite technology, remote sensing images became able to provide spatially distributed measurements. However, the spatial resolution of multispectral satellite images is in the range of meters, tens of meters, or hundreds of meters, which is often not enough for crops with clumped canopy structures, such as trees and vines. Unmanned aerial vehicles (UAVs) can mitigate these spatial and temporal limitations. Lightweight cameras and sensors can be mounted on the UAVs and take high-resolution images. Unlike satellite imagery, the spatial resolution of the UAV images can be at the centimeter-level. UAVs can also fly on-demand, which provides high temporal imagery. In this study, the authors examined different UAV-based approaches of ET estimation at first. Models and algorithms, such as mapping evapotranspiration at high resolution with internalized calibration (METRIC), the two-source energy balance (TSEB) model, and machine learning (ML) are analyzed and discussed herein. Second, challenges and opportunities for UAVs in ET estimation are also discussed, such as uncooled thermal camera calibration, UAV image collection, and image processing. Then, the authors share views on ET estimation with UAVs for future research and draw conclusive remarks.

scholarly journals A review of approaches to estimate wildfire plume injection height within large scale atmospheric chemical transport models – Part 1

2015 ◽  
Vol 15 (6) ◽  
pp. 9767-9813 ◽  
Author(s):  
R. Paugam ◽  
M. Wooster ◽  
S. R. Freitas ◽  
M. Val Martin
Keyword(s):  
Large Scale ◽  
Atmospheric Transport ◽  
Source Region ◽  
Chemical Species ◽  
Chemical Conversion ◽  
Ambient Air ◽  
Transport Models ◽  
Fire Emissions ◽  
Fire Smoke ◽  
In Fire

Abstract. Landscape fires produce smoke containing a very wide variety of chemical species, both gases and aerosols. For larger, more intense fires that produce the greatest amounts of emissions per unit time, the smoke tends initially to be transported vertically or semi-vertically close by the source region, driven by the intense heat and convective energy released by the burning vegetation. The column of hot smoke rapidly entrains cooler ambient air, forming a rising plume within which the fire emissions are transported. This characteristics of this plume, and in particular the height to which it rises before releasing the majority of the smoke burden into the wider atmosphere, are important in terms of how the fire emissions are ultimately transported, since for example winds at different altitudes maybe quite different. This difference in atmospheric transport then may also affect the longevity, chemical conversion and fate of the plumes chemical consituents, with for example very high plume injection heights being associated with extreme long-range atmospheric transport. Here we review how such landscape-scale fire smoke plume injection heights are represented in larger scale atmospheric transport models aiming to represent the impacts of wildfire emissions on component of the Earth system. The use of satellite Earth observation (EO) data is commonly used for this, and detail the EO datasets capable of being used to remotely assess wildfire plume height distributions and the driving characteristics of the causal fires. We also discus both the physical mechanisms and dynamics taking place in fire plumes, and investigate the efficiency and limitations of currently available injection height parameterizations. Finally, we conclude by suggestion some future parameterization developments and ideas on EO data selection that maybe relevant to the instigation of enhanced methodologies aimed at injection height representation.

scholarly journals Physicochemical Quality and Microbial Activity of Dairy Milk with Ozonation

2021 ◽  
Vol 16 (2) ◽  
pp. 117-124
Author(s):  
Dodik Suprapto ◽  
Lilik Eka Radiati ◽  
Chanif Mahdi ◽  
Herly Evanuarini
Keyword(s):  
Microbial Activity ◽  
Electrical Resistance ◽  
Production Capacity ◽  
Ambient Air ◽  
Ozone Exposure ◽  
Ozone Treatment ◽  
Plate Count ◽  
Fresh Milk ◽  
Total Plate Count ◽  
Dairy Milk

The aim of this study was to evaluate the effect of ozone exposure to the physicochemical and microbial activity in dairy milk. The research material was fresh milk from dairy cows and ozone was produced by commercial ozone generator brand HANACO, production capacity up to 0.702 mg/min at 24-27ºC with oxygen source coming from ambient air in the nature. The experiment used ozone treatments for 0, 10, 20, and 30 min with variable of analysis such as density, protein, fat, electrical resistance, total plate count, and malondialdehyde which was analyzed using One Way Annova. The results showed that ozone treatment had no significant effect on the density, protein and fat in dairy milk, but had significant (P<0.05) effect on the electrical resistance, total plate count, and production of malondialdehyde. Electrical resistance and malondialdehyde were increased, while total plate count was decreased over time with the ozone exposure. Ozonation is possible to reducing yield loss on milk production that is caused by microbial activity without changing the physicochemical properties of dairy milk.

Design of the viaducts for the Line 3 of the Riyadh Metro LRT in Saudi Arabia

2018 ◽  
Author(s):  
Paul-Emile Durand ◽  
Lucas Wise ◽  
Emmanuel Joy ◽  
Alain Rossetto
Keyword(s):  
Saudi Arabia ◽  
Large Scale ◽  
Parametric Design ◽  
Full Range ◽  
Design Approach ◽  
Construction Site ◽  
Box Girder ◽  
Construction Engineering ◽  
Long Span ◽  
Metro Project

<p>In June 2013, three consortia were awarded the three construction packages that constitute the whole Riyadh Metro Project in Saudi Arabia for a total of 6 lines and 180 kilometres.</p><p>International Bridge Technologies was in charge, as a subconsultant of Idom, of the complete structural scope of services for the 25.6 km of elevated viaduct that Riyadh Metro Package 2 comprises (Line 3, around 41.6 km, out of which 25.6 km are elevated). This scope consisted of the full range of services from conceptual tender design to final detailed design, including shop drawings production, construction engineering and construction site support.</p><p>The Line 3 elevated viaduct consists of a three-cells precast segmental box-girder with typical simply-supported spans of 37 m and special continuous spans of 50 m. Six long span structures with spans varying from 60 m to 95 m were required for the special crossings over existing interchanges. Typical and continuous spans are erected span-by-span with an overhead truss while long spans are erected in balanced cantilever with cranes on the ground or lifting frames on the deck.</p><p>The present paper is centred on the design of the elevated viaduct and presents the different structures with key features and how they were constructed to permit large scale standardisation and speed of construction. Some key design aspects are developed, in particular the design approach for the 3-cells box-girder as the most effective solution to satisfy the imposed aesthetic criteria. This paper also exposes the design approach adopted to produce a “design-for-demand” by relying as much as practically possible on a realistic modelling of the alignment and by limiting parametric design. This allowed for an optimisation of material quantities.</p>

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