Testing cover crop species under three soil moisture conditions in a controlled greenhouse environment

Abstract Extreme climatic events, such as drought and heavy rainfall, are increasing with climate change. These events can threaten agroecosystems, including vineyards. Cover crops are often grown in vineyards for various reasons and can be an effective strategy for climate change adaptation. Understanding which cover crop species can establish well under extreme climate conditions is important. We conducted a greenhouse experiment to investigate the responses of nine cover crop species to overwatered and water-deficit conditions. Treatments included (1) overwatered soil condition, watered at 100% field capacity daily, (2) control, watered at 60%–70% every other day, and (3) water deficit, watered at 15%–20% weekly for 53 growing days. Results indicated that the total dry weight of all species decreased (most significantly) under water-deficit conditions. However, pubescent wheatgrass and red fescue did not exhibit any stress symptoms. Apart from alfalfa, all species established well under overwatered conditions despite slight yellowing of foliage for crimson clover and hairy vetch. Pearl millet and yellow sweet clover had the best establishment regardless of conditions. Our results provide important information on the selection of cover crops that can withstand climatic variability and thrive in the extreme conditions linked to the climate change scenario in Canada.