Impacts of organic cropping systems on greenhouse gas emissions, soil mineral nitrogen, and crop yields in field crop production in Québec = Impacts de systèmes culturaux biologiques sur les émissions de gaz à effet de serre, l'azote minéral du sol et les rendements en grandes cultures au Québec

Authors: D'Amours, Joannie
Advisor: Halde, Caroline; Pelster, David
Other Title(s): Impacts de systèmes culturaux biologiques sur les émissions de gaz à effet de serre, l’azote minéral du sol et les rendements en grandes cultures au Québec
Abstract: Organic farming aims to enhance the sustainability of cropping systems, but some soil conservation practices implemented may increase greenhouse gas (GHG) emissions. The main objective of this study was to determine the effects of various organic cropping systems on GHG emissions and crop yields, in Québec, Canada. A field experiment was conducted at the Institut national d'agriculture biologique, over two growing seasons (26 April to 31 October 2019 and 29 April to 12 November 2020), on a sandy loam soil. The randomized complete block design included two controls (perennial forage and bare fallow [BF]) and five organic cropping systems combining different: (i) crop sequences (barley [Hordeum vulgare L.]- grain corn [Zea mays L.], soybean [Glycine max (L.) Merr.]- spring wheat [Triticum aestivum L.], grain corn-soybean); (ii) sources of fertilizers (poultry manure [PM] and/or a fall-seeded green manure [GM] or no source); and (iii) primary tillage intensities (moldboard plough [MP] or chisel plough [CP]). Soil temperature, water content, and mineral N concentrations were evaluated periodically, as well as direct nitrous oxide (N₂O) and methane (CH₄) emissions, which were quantified using non-flow-through non-steady-state chambers and gas chromatography. The lowest cumulative N₂O emissions were found in CP-GM (0.52 ± 0.11 and 3.55 ± 0.72 kg N ha⁻¹ in 2019 and 0.47 ± 0.06 kg N ha⁻¹ in 2020), whereas the highest emissions were found in MP-PM in 2019 (3.55 ± 0.72 kg N ha⁻¹) and BF in 2020 (1.44 ± 0.20 kg N ha⁻¹). During both years, CH₄ emissions varied from -0.65 to +0.18 kg C ha⁻¹ and were similar between cropping systems. Organic cropping system CP-GM minimized the area-scaled N₂O emissions without increasing the yield-scaled N₂O emissions. However, long-term assessment is necessary to determine the agronomic, economic, and environmental benefits of these cropping systems.
Document Type: Mémoire de maîtrise
Issue Date: 2022
Open Access Date: 20 June 2022
Permalink: http://hdl.handle.net/20.500.11794/73610
Grantor: Université Laval
Collection:Thèses et mémoires

Files in this item:
Description SizeFormat 
38083.pdf4.35 MBAdobe PDFThumbnail
View/Open
All documents in CorpusUL are protected by Copyright Act of Canada.