7 results on '"Unc, Adrian"'
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2. The impacts of rock pulverization on soil quality and functional soil nematode and respiration properties of boreal lands converted from forest to agricultural use.
- Author
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Young, Erika H., Vallotton, Jeremiah D., Kedir, Amana J., Medaiyese, Ayodeji O., Goyer, Claudia, Comeau, Louis-Pierre, and Unc, Adrian
- Subjects
SOIL respiration ,SOIL quality ,FOREST soils ,MINERAL dusts ,HISTOSOLS ,SOIL composition - Abstract
Rock pulverization is recommended when converting boreal forests to agricultural land use to facilitate tillage operations. Resulting rock dust incorporation might alter physical, chemical, and biological properties of soils. We assessed soil nematode trophic group abundances and indices, basal and burst respiration, and phosphorus extractability after land use conversion (LUC) and recent pulverization (<1 year) on three soil types in eastern Newfoundland, Canada. Nine treatments representing varied pulverization statuses (managed pulverized, managed unpulverized, natural) were nested in soil type (Podzol, Luvisol, and Organic). Conversion to agriculture impacted soil quality more than the recent rock pulverization. Nonetheless, nematode indices (fungivore/bacterivore, fungivore/fungivore+bacterivore, fungivore + bacterivore/herbivore) suggested no significant functional differences with either LUC or pulverization. Soil organic matter (SOM) and pH were substantial direct and indirect drivers of nematode community composition and soil respiration, mainly by altering availability of aluminium and iron. The functional parameters diverged between Organic and mineral soils. For all soils, most respiration parameters were significantly related to SOM, pH, available iron and aluminium. For nematodes, significant relationships were identified in the Organic soil: bacterivores and fungivores abundances were inversely related to SOM, and bacterivore abundance was positively related to pH. While for the mineral soils, citric acid extracted more phosphorus than the Mehlich-3 or water methods, Mehlich-3 was most effective for the Organic soil. Pulverization did not affect phosphorus extractability. The distinct relationships between soil quality properties and functional parameters between mineral and Organic soils are of interest for further investigations into the concepts of soil quality and soil health. Quand on souhaite adapter la forêt boréale à l'agriculture, on préconise de pulvériser le roc pour faciliter les labours. L'incorporation de la poussière rocheuse au sol peut cependant en altérer les propriétés physiques, chimiques et biologiques. Les auteurs ont évalué l'abondance des groupes trophiques de nématodes dans le sol et leurs indices, ainsi que le taux de respiration de base, l'explosion oxydative et l'extractabilité du phosphore après conversion de la vocation des terres (CVT) et pulvérisation récente du roc (moins d'un an) pour trois types de sol de l'est de Terre-Neuve, au Canada. Ils ont combiné différents degrés de pulvérisation (gestion de la pierre pulvérisée, gestion de la pierre non pulvérisée, état naturel) et types de sols (podzols, luvisols et sols organiques) en neuf traitements. La conversion en terre agricole a plus d'impact sur la qualité du sol que la pulvérisation récente du roc. Malgré cela, les indices des nématodes (fongivore/bactérivore, fongivore/fongivore+bactérivore, fongivore+bactérivore/herbivore) laissent croire qu'il n'existe aucune différence sensible entre la CVT et la pulvérisation, sur le plan fonctionnel. La matière organique du sol (MOSL) et le pH sont d'importants paramètres qui affectent directement et indirectement la composition de la population de nématodes et la respiration du sol, essentiellement parce qu'ils modifient la disponibilité de l'aluminium et du fer. Les paramètres fonctionnels ne sont pas les mêmes pour les sols organiques et les sols minéraux. Dans tous les sols, la majorité des paramètres de la respiration présentent une relation significative avec la MOS, le pH ainsi que la quantité de fer et d'aluminium disponible. Les auteurs ont établi des liens significatifs entre les nématodes et le sol organique : l'abondance de nématodes bactérivores et fongivores est inversement reliée à la quantité de MOS, alors que la population de bactérivores est positivement corrélée au pH. En revanche, dans les sols minéraux, l'acide citrique extrait plus de phosphore que la méthode Mehlich-3 ou l'extraction à l'eau, tandis que la technique Mehlich-3 s'avère plus efficace pour le sol organique. La pulvérisation ne modifie pas l'extractibilité du phosphore. Les liens évidents entre les propriétés qualitatives et les paramètres fonctionnels des sols minéraux et organiques mériteraient qu'on entreprenne des recherches plus poussées sur les concepts que sont la qualité et la vitalité du sol. [Traduit par la Rédaction] [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
3. The utility of biochar for increasing the fertility of new agricultural lands converted from boreal forests.
- Author
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Abedin, Joinal and Unc, Adrian
- Subjects
TAIGAS ,BIOCHAR ,FARMS ,SOIL fertility ,SOIL quality ,FOREST soils ,SOILS - Abstract
Copyright of Canadian Journal of Soil Science is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2022
- Full Text
- View/download PDF
4. The rate dependent efficacy of biochar for crop yield and nutrition on Podzols newly converted from boreal forests.
- Author
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Abedin, Joinal and Unc, Adrian
- Subjects
- *
TAIGAS , *CROP yields , *BIOCHAR , *PLANT biomass , *CLIMATE change , *MICROBIAL inoculants , *NUTRIENT uptake - Abstract
Under climate change and local and global food security pressures conversion to agricultural lands on Podzols developed under boreal forests is accelerating across the global north. After conversion Podzols, acid and sandy, are infertile requiring significant management to allow economic production. Biochar, while less useful on fertile soils, may accelerate fertility gains on such marginal lands; it is already considered or land-applied by local farmers, under minimal guidance. A multi-year experiment assessed the utility of single or split application of biochar (BC), and of BC doses, for beet yields and nutrient uptake on newly converted Podzols. Time and rate-dependent progression of yields, macro- and micro-nutrients uptake, all parameters identified of interest by northern farmers, were evaluated. Kiln-derived hardwood biochar was added at 0, 10, 20, 40 or 80 Mg BC-C ha−1 (BC 0 to 80) either as single or as double application. Beet yields and elemental compositions were assessed over 4 years after biochar application. Work was done on a private farm in Labrador, Canada, under a scenario relevant to the boreal north. BC 0 could not sustain significant crop growth, suggesting that post-conversion mineralization of residual soil organic matter cannot support plant growth. In the first one to three years after application of biochar yields increased above the control, but statistically independent of application rates. A statistically significant positive biochar-rate to yield dependency was verifiable only in year 4. Nevertheless, biochar's positive effect on yields declined with time after application: e.g., BC 10 matched BC 0 yields in year 4. For the first three years, root nitrogen (N) concentrations were inversely correlated to yields and plant N% declined with biochar rate. In year 4 plant N% was directly correlated to plant biomass. In general, partitioning of nutrients between beet leaves and roots was not discernibly affected by the rate of biochar; an exception was boron whose preferential accumulation in leaves was directly related to the rate of biochar, indicating a role for the biochar for its mobilization. Biochar had an immediate positive effect on the beet yields and affected plant stoichiometry. Initially this was independent of the biochar rate. Biochar's utility declined with time at a rate inversely related to its application rate. Biochar is a recommendable fertility management tool for infertile, newly converted boreal Podzols; rates in the range of 10 Mg BC-C ha-1 may be repeated annually or every few years as practically feasible. Long term utilization requires further monitoring of micronutrients availability and uptake to inform any necessary management adjustments. Fertilizer management must consider the time since biochar's addition to soil. • Unmanaged Podzols on freshly converted boreal forest are infertile. • Biochar addition increases beet yield and yield quality, initially rate-independent. • A rate-dependent impact of biochar on yields and yield quality was noted in year 4. • Biochar's benefit fades over time at a rate inverse to its application rate. • Repeated, small biochar doses are recommendable over large single applications. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
5. Identifying learning outcomes for a Canadian pedology field school: addressing the gap between new graduates' skills and the needs of the current job market.
- Author
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Masse, Jacynthe, Yates, Thomas, Krzic, Maja, Unc, Adrian, Chen, Z. Chi, Quideau, Sylvie, Hodgson, Kyle, and Warren, C. James
- Subjects
SOIL science ,SOIL surveys ,SOIL formation ,SOIL mapping ,ABILITY - Abstract
Copyright of Canadian Journal of Soil Science is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2019
- Full Text
- View/download PDF
6. Temporal stability of soil apparent electrical conductivity (ECa) in managed podzols.
- Author
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Badewa, Emmanuel, Unc, Adrian, Cheema, Mumtaz, and Galagedara, Lakshman
- Subjects
- *
ELECTRIC conductivity , *SOIL moisture , *SOILS , *PODZOL , *SOIL salinity , *SILT - Abstract
The spatial variability in soil physical and hydraulic properties for a managed podzol was assessed using soil apparent electrical conductivity (ECa). Two EMI sensors, the multi-coil (MC) and multi-frequency (MF), were adopted for measurement of ECa on a silage- corn experimental plot in western Newfoundland, Canada. Results demonstrated a significant relationship between the ECa mean relative differences (MRD) and the soil moisture content MRD (R2 = 0.33 to 0.70) for both MC and MF sensors. The difference in depth sensitivity between MC and MF sensors accounted for the variation (0.015 to 0.09) in ECa standard deviation of the relative differences. A significant linear relationship was found between the ECa MRD and sand (R2 = 0.35 and 0.53) or silt (R2 = 0.43), but not with clay (R2 = 0.06 and 0.16). The spatial variability of the ECa-based predictions (CV = 3.26 to 27.61) of soil properties was lower than the measured values (CV = 5.56 to 41.77). These results inferred that the temporal stability of ECa might be a suitable proxy to understand the spatial variability of soil physical and hydraulic properties in agricultural podzols. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
7. Development of a protocol for sampling faecal coliform bacteria originating from manure in the vadose zone
- Author
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Goss, Michael J. and Unc, Adrian
- Subjects
MANURES ,POLLUTION ,ZONE of aeration - Published
- 2000
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