In situ estimation of foliar nitrogen in wild blueberry using reflectance spectra

2012 ◽  
Vol 92 (6) ◽  
pp. 1155-1161 ◽  
Author(s):  
R. Maqbool ◽  
D. C. Percival ◽  
M. S. Adl ◽  
Q. U. Zaman ◽  
D. Buszard
Keyword(s):  
Nutrient Management ◽  
Reflectance Spectra ◽  
Management Tool ◽  
Biochemical Basis ◽  
Foliar Nitrogen ◽  
Foliar N ◽  
Spectral Ranges ◽  
Mean Square Errors ◽  
Wild Blueberry

Maqbool, R., Percival, D. C., Adl, M. S., Zaman, Q. U. and Buszard, D. 2012. In situ estimation of foliar nitrogen in wild blueberry using reflectance spectra. Can. J. Plant Sci. 92: 1155–1161. Remote sensing techniques have the potential to serve as an important nutrient management tool in wild blueberry. The potential of visible (VIS), near infrared (NIR) and shortwave infrared (SWIR) spectroscopy was evaluated during 2006 (sprout/vegetative phase of production) to estimate foliar nitrogen (N). Canopy reflectance measurements were taken from two nutrient management experimental sites located in Nova Scotia (NS) and New Brunswick (NB). Partial least squares regression (PLSR) estimated foliar N, giving the coefficients of determination (R 2) values ranging from 0.69 to 0.85, and root mean square errors of cross validation (RMSECV) from 0.16% (±8.29% of mean) to 0.24% (±12.43% of mean) for different spectral ranges used in this study. The green peak region located in the VIS region best estimated foliar N. The tested spectral ranges differed in their predictive ability, but generally followed the biochemical basis. Variable importance in projection scores (VIP), regression vector coefficients and PLSR loading weights (LWs) plots highlight the importance of wavebands (∼550 nm, ∼610 nm, 1510 nm, ∼1690 nm, ∼1730 nm, ∼1980 nm and ∼2030 nm) for in situ foliar N estimations. Thus, it was concluded that reflectance spectra may be used to estimate and ultimately map foliar N in wild blueberry production. The results illustrated the ability of multivariate techniques, such as PLSR to explore hyperspectral data and estimate leaf tissue nutrient content.

scholarly journals Depth-wise variations of soil physicochemical properties in the apple growing area of Mustang district, Nepal

2020 ◽  
Vol 3 (2) ◽  
pp. 92-103
Author(s):  
Rita Amgain ◽  
Dinesh Khadka ◽  
Sushila Joshi ◽  
Rajan Malla
Keyword(s):  
Nutrient Management ◽  
Management Practice ◽  
Science Research ◽  
Management Tool ◽  
Research Centre ◽  
Soil Parameters ◽  
Total N ◽  
Rural Municipality ◽  
Apple Production

Understanding the soil fertility is an important management tool in assessing the nutrient requirement of the crops. Considering this, a study was done to determine depth-wise soil parameters distribution in the apple growing areas of Gharpajhog Rural Municipality, Mustang during October 2019. The total 68 sampling points were selected randomly in the different sites, and collection was done from three depths viz. 0-20cm, 20-40cm and 40-60cm by using soil sampling auger. The soil separates, pH, organic matter, total N, available P2O5 and K2O were determined following standard methods in National Soil Science Research Centre, Khumaltar. The results of the study revealed that the effect of depth was significant in the sand and silt proportion, while non- significant in clay proportion. The highest (40.17±1.57%) sand content was in 40-60cm depth, meanwhile highest (45.64±1.07%) silt content was in surface (0-20cm) depth. In addition to this, soil pH, OM, total N, available P2O5 and K2O were also affected by the depth. The highest (8.27) pH was determined in the lower (40-60cm) depth. On the other hand, highest OM (4.93±0.2%), total N (0.24±0.01%), available P2O5 (43.47±4.35 mg/kg) and available K2O (95.91±5.8 mg/kg) in surface (0.20 cm) depth. The surface depth possessed strong content of studied soil parameters might be due to in-situ incorporation of leaf litter, residue etc. as well as applied manure in the surface. Finally, we can also conclude that the adopted current nutrient management practice should be continued for apple production in the study area.

scholarly journals Modelling the Quality of Bathing Waters in the Adriatic Sea

Water ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1525
Author(s):  
Christian Ferrarin ◽  
Pierluigi Penna ◽  
Antonella Penna ◽  
Vedrana Spada ◽  
Fabio Ricci ◽  
...  
Keyword(s):  
Adriatic Sea ◽  
Management Tool ◽  
Negative Consequences ◽  
Sea Temperature ◽  
Bathing Water Directive ◽  
Bathing Waters ◽  
Diffusion Dynamics ◽  
Study Sites

The aim of this study is to develop a relocatable modelling system able to describe the microbial contamination that affects the quality of coastal bathing waters. Pollution events are mainly triggered by urban sewer outflows during massive rainy events, with relevant negative consequences on the marine environment and tourism and related activities of coastal towns. A finite element hydrodynamic model was applied to five study areas in the Adriatic Sea, which differ for urban, oceanographic and morphological conditions. With the help of transport-diffusion and microbial decay modules, the distribution of Escherichia coli was investigated during significant events. The numerical investigation was supported by detailed in situ observational datasets. The model results were evaluated against water level, sea temperature, salinity and E. coli concentrations acquired in situ, demonstrating the capacity of the modelling suite in simulating the circulation in the coastal areas of the Adriatic Sea, as well as several main transport and diffusion dynamics, such as riverine and polluted waters dispersion. Moreover, the results of the simulations were used to perform a comparative analysis among the different study sites, demonstrating that dilution and mixing, mostly induced by the tidal action, had a stronger effect on bacteria reduction with respect to microbial decay. Stratification and estuarine dynamics also play an important role in governing microbial concentration. The modelling suite can be used as a beach management tool for improving protection of public health, as required by the EU Bathing Water Directive.

scholarly journals In situ feeding as a new management tool to conserve orphaned Eurasian lynx (lynx lynx)

2021 ◽  
Author(s):  
Joe Premier ◽  
Martin Gahbauer ◽  
Franz Leibl ◽  
Marco Heurich
Keyword(s):  
Management Tool ◽  
Lynx Lynx ◽  
Eurasian Lynx ◽  
In Situ Feeding

scholarly journals Experimental determination of reflectance spectra of Antarctic krill (Euphausia superba) in the Scotia Sea

2021 ◽  
pp. 1-13
Author(s):  
Anna Belcher ◽  
Sophie Fielding ◽  
Andrew Gray ◽  
Lauren Biermann ◽  
Gabriele Stowasser ◽  
...  
Keyword(s):  
Antarctic Krill ◽  
Euphausia Superba ◽  
Reflectance Spectra ◽  
Spectral Signature ◽  
Absorption Feature ◽  
Scotia Sea ◽  
Surface Ocean ◽  
Measuring Surface ◽  
Ground Truthing

Abstract Antarctic krill are the dominant metazoan in the Southern Ocean in terms of biomass; however, their wide and patchy distribution means that estimates of their biomass are still uncertain. Most currently employed methods do not sample the upper surface layers, yet historical records indicate that large surface swarms can change the water colour. Ocean colour satellites are able to measure the surface ocean synoptically and should theoretically provide a means for detecting and measuring surface krill swarms. Before we can assess the feasibility of remote detection, more must be known about the reflectance spectra of krill. Here, we measure the reflectance spectral signature of Antarctic krill collected in situ from the Scotia Sea and compare it to that of in situ water. Using a spectroradiometer, we measure a strong absorption feature between 500 and 550 nm, which corresponds to the pigment astaxanthin, and high reflectance in the 600–700 nm range due to the krill's red colouration. We find that the spectra of seawater containing krill is significantly different from seawater only. We conclude that it is tractable to detect high-density swarms of krill remotely using platforms such as optical satellites and unmanned aerial vehicles, and further steps to carry out ground-truthing campaigns are now warranted.

scholarly journals Nutrient Management Effects on Wine Grape Tissue Nutrient Content

Plants ◽  
2022 ◽  
Vol 11 (2) ◽  
pp. 158
Author(s):  
John L. Havlin ◽  
Robert Austin ◽  
David Hardy ◽  
Adam Howard ◽  
Josh L. Heitman
Keyword(s):  
Nutrient Management ◽  
Nutrient Status ◽  
Nutrient Content ◽  
Field Studies ◽  
Soil Test ◽  
Full Bloom ◽  
Management Decisions ◽  
Late Season ◽  
Foliar N ◽  
N Management

With limited research supporting local nutrient management decisions in North Carolina grape (Vitis vinifera) production, field studies (2015–17) were conducted to evaluate late season foliar nitrogen (N) application on leaf and petiole N concentration and yeast assimilable N (YAN) in the fruit. Foliar urea (1% v/v) was applied at different rates and application times beginning pre-and post-veraison. Compared to soil applied N, late season foliar N substantially enhanced petiole N and grape YAN. Smaller split N applications were generally more effective in increasing YAN than single larger N rates. These data demonstrate the value of assessing plant N content at full bloom with petiole N analysis or remote sensing to guide foliar N management decisions. Additional field studies (2008–11) were conducted to evaluate pre-bud soil applied phosphorus (P) and potassium (K) effects on petiole P and K nutrient status. Fertilizer P and K were initially broadcast applied (0–896 kg P2O5 ha−1; 0–672 kg K2O ha−1) prior to bud-break in 2008–09 and petiole P and K at full bloom soil test P and K were monitored for three to four years after application. Soil test and petiole P and K were significantly increased with increasing P and K rates, which subsequently declined to near unfertilized levels over the sampling time depending on site and P and K rate applied. These data demonstrate the value of annually monitoring petiole P and K levels to accurately assess plant P and K status to better inform nutrient management decisions.

scholarly journals Tilt error in cryospheric surface radiation measurements at high latitudes: a model study

2016 ◽  
Vol 10 (2) ◽  
pp. 613-622 ◽  
Author(s):  
Wiley Steven Bogren ◽  
John Faulkner Burkhart ◽  
Arve Kylling
Keyword(s):  
Measurement Error ◽  
Total Error ◽  
Surface Radiation ◽  
Cloud Optical Depth ◽  
Model Study ◽  
Tilt Error ◽  
Total Measurement Error ◽  
Spectral Ranges ◽  
Radiation Measurements

Abstract. We have evaluated the magnitude and makeup of error in cryospheric radiation observations due to small sensor misalignment in in situ measurements of solar irradiance. This error is examined through simulation of diffuse and direct irradiance arriving at a detector with a cosine-response fore optic. Emphasis is placed on assessing total error over the solar shortwave spectrum from 250 to 4500 nm, as well as supporting investigation over other relevant shortwave spectral ranges. The total measurement error introduced by sensor tilt is dominated by the direct component. For a typical high-latitude albedo measurement with a solar zenith angle of 60°, a sensor tilted by 1, 3, and 5° can, respectively introduce up to 2.7, 8.1, and 13.5 % error into the measured irradiance and similar errors in the derived albedo. Depending on the daily range of solar azimuth and zenith angles, significant measurement error can persist also in integrated daily irradiance and albedo. Simulations including a cloud layer demonstrate decreasing tilt error with increasing cloud optical depth.

Produced Water Handling Using Downhole Oil Water Separation Study Case Onshore & Offshore Fields Abu Dhabi

2021 ◽  
Author(s):  
Abdelhak Ladmia ◽  
Dr. Younes bin Darak Al Blooshi ◽  
Abdullah Alobedli ◽  
Dragoljub Zivanov ◽  
Myrat Kuliyev ◽  
...  
Keyword(s):  
Produced Water ◽  
Operating Cost ◽  
Cost Effective ◽  
Management Tool ◽  
Water Separation ◽  
Field Development ◽  
Effective Manner ◽  
Oil Water Separation ◽  
Oil Water

Abstract The expected profiles of the water produced from the mature ADNOC fields in the coming years imply an important increase and the OPEX of the produced and injected water will increase considerably. This requires in-situ water separation and reinjection. The objective of in-situ fluid separation is to reduce the cost of handling produced water and to extend the well natural flow performance resulting in increased and accelerated production. The current practice of handling produced water is inexpensive in the short term, but it can affect the operating cost and the recovery in the long term as the expected water cut for the next 10-15 years is forecasted to incease significantly. A new water management tool called downhole separation technology was developed. It separates oil and & gas from associated water inside the wellbore to be reinjected back into the disposal wells. The Downhole Oil Water Separation (DHOWS) Technology is one of the key development strategies that can reduce considerable amounts of produced water, improve hydrocarbon recovery, and minimize field development cost by eliminating surface water treatment and handling costs. The main benefits of DHOWS include acceleration of oil offtake, reduction of production cost, lessening produced water volumes, and improved utilization of surface facilities. In effect, DHOWS technologies require specific design criteria to meet the objectives of the well. Therefore, multi--discipline input data are needed to install an effective DHOWS with a robust design that economically outperforms and boosts oil and/or gas productions. This paper describes the fundamental criteria and workflow for selecting the most suitable DHOWS design for new and sidetracked wells to deliver ADNOC production mandates in a cost-effective manner while meeting completion requirements and adhering to reservoir management guidelines.

scholarly journals In situ predator conditioning of naive prey prior to reintroduction

2019 ◽  
Vol 374 (1781) ◽  
pp. 20180058 ◽  
Author(s):  
Daniel T. Blumstein ◽  
Mike Letnic ◽  
Katherine E. Moseby
Keyword(s):  
Small Groups ◽  
Large Scale ◽  
Management Tool ◽  
Behavioural Ecology ◽  
Ecological Community ◽  
Theme Issue ◽  
Selection For ◽  
Future Work ◽  
Dynamics Of Populations

Many translocations and introductions to recover threatened populations fail because predators kill prey soon after release; a problem exacerbated for predator-naive prey. While pre-release training has been shown to work in some situations, it is time consuming and relies on using inferred predator cues and treating small groups. We review a relatively new and very promising management tool: in situ , pre-release predator conditioning. Here, the goal is to allow prey in large enclosures to live with low densities of predators to accelerate selection for antipredator traits (in an evolutionary sense) or provide prey essential experience with predators that they will later encounter. We review the published results of a large-scale, controlled experiment where we have permitted burrowing bettongs ( Bettongia lesueur ) and greater bilblies ( Macrotis lagotis ) to live with low densities of feral cats ( Felis catus ), a species implicated in their widespread decline and localized extinction. We found that both species could persist with cats, suggesting that future work should define coexistence thresholds—which will require knowledge of prey behaviour as well as the structure of the ecological community. Compared to control populations, predator-naive prey exposed to cats has a suite of morphological and behavioural responses that seemingly have increased their antipredator abilities. Results suggest that predator-conditioned bilbies survive better when released into a large enclosure with an established cat population; future work will determine whether this increased survival extends to the wild. This article is part of the theme issue ‘Linking behaviour to dynamics of populations and communities: application of novel approaches in behavioural ecology to conservation’.

scholarly journals Using Optical Water Types to Monitor Changes in Optically Complex Inland and Coastal Waters

2019 ◽  
Vol 11 (19) ◽  
pp. 2297 ◽  
Author(s):  
Kristi Uudeberg ◽  
Ilmar Ansko ◽  
Getter Põru ◽  
Ave Ansper ◽  
Anu Reinart
Keyword(s):  
Remote Sensing ◽  
Coastal Waters ◽  
Atmospheric Correction ◽  
Suspended Sediments ◽  
Reflectance Spectra ◽  
Water Type ◽  
Colored Dissolved Organic Matter ◽  
Water Color ◽  
Sentinel 2

The European Space Agency’s Copernicus satellites Sentinel-2 and Sentinel-3 provide observations with high spectral, spatial, and temporal resolution which can be used to monitor inland and coastal waters. Such waters are optically complex, and the water color may vary from completely clear to dark brown. The main factors influencing water color are colored dissolved organic matter, phytoplankton, and suspended sediments. Recently, there has been a growing interest in the use of the optical water type (OWT) classification in the remote sensing of ocean color. Such classification helps to clarify relationships between different properties inside a certain class and quantify variation between classes. In this study, we present a new OWT classification based on the in situ measurements of reflectance spectra for boreal region lakes and coastal areas without extreme optical conditions. This classification divides waters into five OWT (Clear, Moderate, Turbid, Very Turbid, and Brown) and shows that different OWTs have different remote sensing reflectance spectra and that each OWT is associated with a specific bio-optical condition. Developed OWTs are distinguishable by both the MultiSpectral Instrument (MSI) and the Ocean and Land Color Instrument (OLCI) sensors, and the accuracy of the OWT assignment was 95% for both the MSI and OLCI bands. To determine OWT from MSI images, we tested different atmospheric correction (AC) processors, namely ACOLITE, C2RCC, POLYMER, and Sen2Cor and for OLCI images, we tested AC processors ALTNNA, C2RCC, and L2. The C2RCC AC processor was the most accurate and reliable for use with MSI and OLCI images to estimate OWTs.

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