WATER4EVER Project: Use of Mohid-Land to model water balance for deficit irrigation in vineyards

Agriculture is the largest water consumer, with 70% of the diverted water used in irrigation, and is a key source of diffuse pollution, promoting eutrophication and biodiversity loss. WATER4EVER Project (http://water4ever.eu/) aims to increase irrigation water and fertilization efficiencies through precision farming. The project has a technological component based on optical sensors; a modelling component at local and catchment scales; and a fieldwork component based on 11 case studies where the new sensors and modelling tools are combined with field data and remote sensing. MOHID-Land is a physically-based, spatially distributed, continuous, variable time step model for the water and property cycles. It integrates four compartments (atmosphere, porous media, soil surface, and river network). MOHID-Land model has been calibrated at plot scale in two study cases, with different conditions: (i) Vinha do Mel-Companhia das Lezírias (Portugal) is an irrigated vineyard of 14000m 2 with limited slope, while (ii) the Cannona Erosion Plots (Italy) are 1200m 2 portions of a rainfed hillslope vineyard, with different inter-rows' management. In both sites water inputs (precipitation and irrigation), meteorological parameters and soil water content at different depths have been monitored during two years, using field sensors. Direct runoff measurements are available for the Cannona Plots. The vegetative development of the vineyards has been estimated from remote imagery. The field and remote datasets were used to calibrate and validate the model, by comparing with simulated values of SWC and LAI. The model was considered adequate to support the IrrigaSys decision support system, using the Portuguese study case as reference for weekly irrigation recommendation in the region. For the Italian plot (rainfed) the model allowed the estimation of the water balance in two growing seasons with contrasting weather conditions, assessing the effect of different soil managements and the needing to irrigate.