Vineyards are highly heterogeneous systems where climate, soil, and management parameters are capable of influencing water loss by evapotranspiration (ET) across many spatial and temporal scales. To address vineyard variability of ET a multi-method approach combining the use of in-field atmometer ET gauges and the FAO-56 dual crop coefficient procedure were employed. Spatial variability was addressed at two research sites in the Niagara (Ontario, Canada) growing region, Beamsville and Jordan, across three different cultivars: Chardonnay, Riesling and Pinot Noir. It was hypothesized that variability in climatic controls including air temperature, precipitation, solar radiation, and wind dynamics, would influence the variability in crop ET for each cultivar at both vineyards. Reference ET (ET o) and water stress adjusted crop ET (ET c adj) were consistent for white cultivars across each study site. Pinot Noir grapevines, however, saw lower daily ET o, likely due to increased canopy shading, or reduced wind turbulence to the canopy. The coefficient K cb, which accounts for transpiration, was consistent for all cultivars at both sites, while K e, the evaporation coefficient, showed a relationship between the soil water balance controlling water loss, especially regarding the Pinot Noir block. Water stress, represented by K s, was present at harvest for both Riesling blocks, and Beamsville Chardonnay, and was associated with optimal Brix values. Overall, Beamsville blocks were associated closely with net solar radiation, relative humidity and vapor pressure deficits, suggesting sensitivity to atmospheric controls. Jordan grapevine ET c adj was controlled by volumetric water content, air temperature and water-use-efficiency, indicating relationships between ET c adj and water stress. The use of atmometers in-field, with adjustments by the FAO-56 dual crop coefficient approach, is a simple and cost-effect method that would allow growers to understand differences in climate-based terroir components and water loss by ET across multiple spatial and temporal scales within their vineyards.

A new flow for Canadian young hydrologists: Key scientific challenges addressed by research cultural shiftsCaroline Aubry-Wake1, Lauren D. Somers2,3, Hayley Alcock4, Aspen M. Anderson5, Amin Azarkhish6, Samuel Bansah7, Nicole M. Bell8, Kelly Biagi9, Mariana Castaneda-Gonzalez10, Olivier Champagne9, Anna Chesnokova10, Devin Coone6, Tasha-Leigh J. Gauthier11, Uttam Ghimire6, Nathan Glas6, Dylan M. Hrach11, Oi Yin Lai14, Pierrick Lamontagne-Halle3, Nicolas R. Leroux1, Laura Lyon3, Sohom Mandal12, Bouchra R. Nasri13, Nataša Popović11, Tracy. E. Rankin14, Kabir Rasouli15, Alexis Robinson16, Palash Sanyal17, Nadine J. Shatilla9, 18, Brandon Van Huizen11, Sophie Wilkinson9, Jessica Williamson11, Majid Zaremehrjardy191 Centre for Hydrology, University of Saskatchewan, Saskatoon, SK, Canada2 Civil and Environmental Engineering, Massachusetts Institute of Technology, MA, USA3 Department of Earth and Planetary Sciences, McGill University, Montreal QC4 Department of Natural Resource Science, McGill University, Montreal, QC, Canada5 Department of Earth Sciences, Simon Fraser University, Burnaby, BC, Canada6 School of Engineering, University of Guelph, Ontario, ON, Canada7 Department of Geological Sciences, University of Manitoba, Winnipeg, Canada8 Centre for Water Resources Studies, Department of Civil & Resource Engineering, Dalhousie University, Halifax, NS, Canada9 School of Geography and Earth Sciences, McMaster University, Hamilton, ON, Canada.10 Department of Construction Engineering, École de technologie supérieure, Montreal, QC, Canada11 Department of Geography & Environmental Management, University of Waterloo, Waterloo, ON, Canada12 Department of Geography and Environmental Studies, Ryerson University, Toronto, ON, Canada13 Department of Mathematics and Statistics, McGill University, Montréal, Qc, Canada14 Geography Department, McGill University, Montreal, QC, Canada15 Meteorological Service of Canada, Environment and Climate Change Canada, Dorval, QC, Canada16 Department of Geography and Planning, University of Toronto, Toronto, ON17 Global Institute for Water Security, University of Saskatchewan.18 Lorax Environmental Services Ltd, Vancouver, BC, Canada.19 Department of Earth and Atmospheric Sciences, University of Alberta, Edmonton, AB, Canada