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Institution

Agriculture and Agri-Food Canada

FacilityOttawa, Ontario, Canada
About: Agriculture and Agri-Food Canada is a facility organization based out in Ottawa, Ontario, Canada. It is known for research contribution in the topics: Population & Soil water. The organization has 10921 authors who have published 21332 publications receiving 748193 citations. The organization is also known as: Department of Agriculture and Agri-Food.
Topics: Population, Soil water, Manure, Tillage, Loam


Papers
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Journal ArticleDOI
TL;DR: In this article, a second-order polynomial model was developed using multiple linear regression analysis to determine the optimum processing conditions that give maximum extraction yield, viscosity, hue and emulsion stability, as well as, minimum protein content for the gum extracted from Lepidium perfoliatum seed.

209 citations

Journal ArticleDOI
TL;DR: In this paper, microwave assisted extraction (MAE) and high performance liquid chromatographic (HPLC) procedure was applied to measure ergosterol in soil samples, and the E-to-FB conversion factors were determined in six species of fungi grown in vitro.
Abstract: Determination of fungal biomass (FB) and FB-carbon (FB-C) from soil ergosterol concentration is diAcult because of unknown ergosterol-to-fungal biomass (E-to-FB) conversion factors and ineAcient ergosterol extraction methods. We applied a microwave-assisted extraction (MAE) and high performance liquid chromatographic (HPLC) procedure to measure ergosterol in soil samples. The E-to-FB conversion factors were determined in six species of fungi grown in vitro. The MAE method was fast and extracted up to nine times more soil ergosterol than a classical refluxing saponification method. Soil ergosterol was separated and quantified rapidly (<10 min) by HPLC. Alternaria alternata, Chaetomium globosum, Fusarium oxysporum, Penicillum chrysogenum, Rhizopus stolonifer and Trichoderma harzianum isolated from soil and plant matrices were grown in batch. Ergosterol and biomass content were determined in mycelia harvested during the stationary and exponential phases of growth. Total mycelial ergosterol ranged from 180 to 2178 mg, and total dry biomass ranged from 17 to 595 mg. Total ergosterol and fungal dry biomass were strongly associated (r 2 = 0.95). The C content in mycelial mats averaged 43% (21.1, SD), and was similar among fungal species and growth phases. The analyses of variance showed that the E-to-FB ratio was similar among fungal species or growth phase. An average ergosterol concentration of 4 m gm g ˇ1 dry biomass was determined for the six species of fungi, which gave a conversion factor of 250 mg dry biomass mg ˇ1 ergosterol. The MAE method recovered an average of 62% (211%, SD) of the ergosterol added in mycelial mats to soils prior to extraction, and its recovery was independent of soil properties. The E-to-FB ratio and percent recovery of mycelial ergosterol helped establish for the first time relationships determining soil FB and FB-C from soil ergosterol concentration. The amount of FB ranged from 155 to 4745 mg g ˇ1 and that for FB-C ranged from 67 to 2040 m gg ˇ1 for diAerent soils, and was higher in samples taken from native undisturbed land than in samples taken from adjacent cultivated fields. Measurement of soil ergosterol concentration is a useful estimate content of the living soil FB. 7 2000 Elsevier Science Ltd. All rights reserved.

208 citations

Journal ArticleDOI
TL;DR: The results suggest a lack of comfort may be apparent in reduced time spent lying and a subsequent increase in time spent standing without eating and an increase in the bout duration of lying suggests that cows on concrete flooring have difficulty standing up and lying down.

208 citations

Journal ArticleDOI
TL;DR: In this paper, the authors review three plant fluorescence components related to four sensing approaches (variable chlorophyll fluorescence, leaf chlorophyl content-related fluorescence emission ratio, blue-green fluorescence and epidermal screening of chlorophyLL fluorescence by phenolic compounds) from the perspective of their relevance to N fertilization management of agricultural crops.
Abstract: The optimization of nitrogen (N) fertilization is the object of intense research efforts around the world. Overfertilization is commonly used as a form of insurance against uncertain soil fertility level. However, this practice results in lower nitrogen use efficiency, high levels of residual N after harvest, and losses in the environment. Determining an N recommendation that would preserve actual crop requirements, profitability of the farm, and quality of the environment has been subjected to a number of research initiatives with a variable degree of success. On one hand, soil tests are capable of estimating the intensity of N release at any point in time, but rarely the capacity factor over a longer period. On the other hand, in the context of in-season N applications, crops are often considered good integrators of factors such as the presence of mineral N, climatic conditions, soil properties, and crop management. Strategies have been proposed with plant sensor-based diagnostic information for N recommendations, but the sensitivity of reflectance-based parameters alone do not provide complete satisfaction (delayed sensitivity, need of specific chlorophyll, biomass or cover fraction ranges, lack of specificity to the N stress). Fluorescence sensing methods have been used to monitor crop physiology for years, and they may offer solutions for N status diagnosis over reflectance-based methods. In this paper, we review three plant fluorescence components related to four sensing approaches—variable chlorophyll fluorescence, leaf chlorophyll content-related fluorescence emission ratio, blue-green fluorescence, and epidermal screening of chlorophyll fluorescence by phenolic compounds—from the perspective of their relevance to N fertilization management of agricultural crops. We examine the existence of N-induced changes in each case, together with applications and limitations of the approach. Among these approaches, the fluorescence emission ratio method is the most important and the most widely used to date. However, blue-green fluorescence and epidermal screening of chlorophyll fluorescence by phenolic compounds has also received a great deal of attention particularly with the recent commercial release of instruments which can measure in real time and in vivo both the leaf chlorophyll content and several phenolic compounds (anthocyanins, flavonoids, hydroxycinnamic acids). Overall, our conclusion is that fluorescence-based technologies allow for highly sensitive plant N status information, independently from soil interference, leaf area, or biomass status. They also allow for probing not only the chlorophyll status but also other physiological parameters known to react to N fertility conditions. These new parameters have the potential to provide new N status indicators that can be assessed remotely in a precision agriculture context.

208 citations


Authors

Showing all 10964 results

NameH-indexPapersCitations
Fereidoon Shahidi11995157796
Miao Liu11199359811
Xiang Li97147242301
Eviatar Nevo9584840066
Tim A. McAllister8586232409
Hubert Kolb8442025451
Daniel M. Weary8343722349
Karen A. Beauchemin8342322351
Nanthi Bolan8355031030
Oene Oenema8036123810
Santosh Kumar80119629391
Yueming Jiang7945220563
Denis A. Angers7625619321
Tong Zhu7247218205
Christophe Lacroix6935315860
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Performance
Metrics
No. of papers from the Institution in previous years
YearPapers
202314
202282
20211,078
20201,035
2019992
2018988