David Bruce McKenzie

Dr. David Bruce McKenzie

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Research Focus & Metrics

Academic Career Length

28Years (1999-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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12 January 2019 in Agronomy
Verified
Journal Article
Open access
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MCMarcos Cordeiro
Marcos Cordeiro
ARAlan Rotz
Alan Rotz
RKRoland Kroebel
Roland Kroebel
KBKaren Beauchemin
Karen Beauchemin
DHDerek Hunt
Derek Hunt
DMDavid Bruce McKenzie
David Bruce McKenzie
Forage production in northern latitudes is challenging and uncertain in the future. In this case-study, the integrated farm system model (IFSM) was used to assess the impact of climate change and cropland expansion scenarios on forage production in a dairy farm in Newfoundland, Canada. Climatic projections indicated increases in temperature in the recent past (1990–2016) and under any future climate (2020–2079), thus enhancing agronomic performance. Temperature increases ranged from 2.8 °C to 5.4 °C in winter and from 3.2 °C to 6.4 °C in spring. Small precipitation increases (<10%) create narrower time windows to perform farm operations in the already stringent condition of excess moisture in the region. Results of land use scenarios including expansions of 20, 30, and 40% in cropland area, out of which 5% was dedicated to corn silage and the remainder to grass-legume mixtures, indicated increased yield and total production. Improvements in grass-legume yield ranged from 8% to 52%. The full range of production increases ranged from 11% to 105%. Increments in corn silage yield ranged from 28% to 69%. Total farm corn silage production increases ranged from 29% to 77%. An attainable cropland expansion of 20% would enable the farm to become self-sufficient in forage production under any climate scenario.

1 October 2003 in Canadian Journal of Plant Science
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Journal Article
Open access
AKA. B. Kwabiah
A. B. Kwabiah
MMM. MacPherson
M. MacPherson
DMDavid Bruce McKenzie
David Bruce McKenzie

11 November 2020 in Soil Science Society of America Journal
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Journal Article
Closed access
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AKAmana Jemal Kedir
Amana Jemal Kedir
JNJudith Nyiraneza
Judith Nyiraneza
LGLakshman Galagedara
Lakshman Galagedara
MCMumtaz Cheema
Mumtaz Cheema
KHKelly Anne Hawboldt
Kelly Anne Hawboldt
AUAdrian Unc
Adrian Unc

23 December 2024 in Earth
Verified
Journal Article
Open access
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RERiad Eissa
Riad Eissa
LJLordwin Jeyakumar
Lordwin Jeyakumar
DMDavid Bruce McKenzie
David Bruce McKenzie
JWJianghua Wu
Jianghua Wu
The demand for intensive agriculture to boost food and crop production has increased. High nitrogen (N) fertilizer use is crucial for increasing agricultural productivity but often leads to significant nitrate losses, posing risks to surface and groundwater quality. This study examines the role of biochar as a soil amendment to enhance nutrient retention and mitigate nitrate leaching. By improving nitrogen efficiency, biochar offers a sustainable strategy to reduce the environmental impacts of intensive agriculture while maintaining soil fertility. An incubation study investigated four biochar feedstocks: spruce bark biochar at 550 °C (SB550), hardwood biochar (75% sugar maple) at 500 °C (HW500), sawdust (fir/spruce) biochar at 427 °C (FS427), and softwood biochar at 500 °C (SW500), to identify the most effective nitrate adsorbent. Scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FT-IR) were employed to analyze biochar morphology and surface functional groups. Adsorption isotherms were modeled using the Langmuir and Freundlich equations. The results indicated that surface functional groups, such as aromatic C=C stretching and bending, aromatic C–H bending, and phenolic O–H bending, play crucial roles in enhancing electrostatic attraction and, consequently, the nitrate adsorption capacity of biochar. The equilibrium adsorption data from this study fit well with both the Langmuir and Freundlich isotherm models. Among the four biochar types tested, SB550 exhibited the highest nitrate adsorption capacity, with a maximum of 184 mg/g. The adsorption data showed excellent conformity to the Langmuir and Freundlich models, with correlation coefficients (R2) exceeding 0.987 for all biochar types. These findings highlight the high accuracy of these models in predicting nitrate adsorption capacities.

1 August 1999 in Journal of Food Biochemistry
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Journal Article
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UCU.D. Chavan
U.D. Chavan
Fereidoon ShahidiFereidoon Shahidi
Fereidoon Shahidi
ABA.K. Bal
A.K. Bal
DMDavid Bruce McKenzie
David Bruce McKenzie

1 January 2020 in JBJS Case Connector
Verified
Journal Article
Closed access
AHAlexandra C. Hatchell
Alexandra C. Hatchell
AAAhmed Aoude
Ahmed Aoude
SASultan Aldebeyan
Sultan Aldebeyan
DMDavid Bruce McKenzie
David Bruce McKenzie
PLPeter Lewkonia
Peter Lewkonia
WHWillian de Haas
Willian de Haas
Case: Spine reconstruction after en bloc spondylectomy is challenging and may require multidisciplinary intervention. En bloc spine tumor resection with embolization of local recipient vessels for tumor control limits reconstructive options. Herein, we describe a case where combined efforts from orthopaedic, general, and plastic surgery teams permitted the successful reconstruction of a multilevel lumbar vertebral defect. Conclusion: A fibula-free flap within a titanium cage construct anastomosed to the left gastroepiploic vessels via a pedicled omental flow-through flap is a viable and novel method for reconstruction of a multilevel vertebral defect.