Effet temporaire des rotations courtes sur le drainage des sols organiques cultivés

Authors: Thériault, Laura
Advisor: Caron, Jean
Abstract: In Quebec, most organic soils are used for vegetable production and peat extraction. Although highly productive, organic soils are prone to intense degradation caused by initial drainage and cultivation. This degradation accelerates as the level of the water table drops, and a compacted layer is therefore forming, which can result in the appearance of a perched water table in the root zone. The integration of deep-rooted plants could improve hydraulic conductivity of this compact layer and therefore the drainage of organic soils, as several studies have already demonstrated for compacted mineral soils. The objectives of the project were to identify a plant species to be used in short rotation, to improve water infiltration of degraded organic soils and to assess the residual effects of such rotation on drainage. Experimental plots were planted on cultivated organic soils of Montérégie, on sites with different levels of degradation. During each year of the project, saturated hydraulic conductivity (Ks) measurements were made at the soil surface and at 30-cm depth, and soil penetration resistance (SPR) measurements were done on the entire profile using a digital penetrometer. Matric potential and water table levels were also monitored by data loggers during the growth seasons. We observed significant, albeit small, effects on Ks in the second year of rotation at each site, but these effects disappeared rapidly the following year when the vegetable crop was reintroduced. It can be concluded that the effect of the short rotations tested is marginal compared to the expected duration as it does not persist after the end of rotation in this soil type.
Document Type: Mémoire de maîtrise
Issue Date: 2018
Open Access Date: 7 May 2018
Permalink: http://hdl.handle.net/20.500.11794/29626
Grantor: Université Laval
Collection:Thèses et mémoires

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