Future climate will reshape inter-row grass mowing in vineyards: A modelling approach for optimized agronomic management

Climate change exerts mounting pressure on major agroecosystems, jeopardizing both their productivity and long-term sustainability. Vineyards, as multi-layer cropping systems, require effective inter-row management to improve grape production and sustain the provision of ecosystem services. Crop models predict the dynamics of the distinct vegetation layers in the system and support the optimization of inter-row practices. In this study, the original UNIFI.GrapeML vine growth model was integrated with a new module to simulate the daily inter-row grass growth in conjunction with the development of the main crop. The model was calibrated and validated in two vineyards located in the Piedmont region. The results showed satisfactory performance simulating grass growth (r = 0.79, RMSE = 31.3 g d.m. m−2) and fractional transpirable soil water (r = 0.93, RMSE = 0.17), for grassed and tilled inter-rows. Moreover, the UNIFI.GrapeML showed satisfactory performance in simulating vine phenology (r = 0.69, RMSE = 6.7 days, on average among all phenological phases), pruned shoot weight (r = 0.74, RMSE = 39.0 g d.m. m−2) and yield (r = 0.55, RMSE = 66.1 g d.m. m−2), in both vineyards. Once validated, the integrated model was applied to assess grass growth in SSP1 2.6, SSP2 4.5 and SSP5 8.5 scenarios. Under future climates, the model demonstrated that the onset of grass growth occurred earlier, and the frequency of required cuts between March and November increased from a minimum of + 4.2 % in SSP2 4.5 to a maximum of + 5.7 % in SSP1 2.6 compared to the present. Furthermore, simulated grass growth trends revealed different redistribution of operating costs and CO2 emissions for mowing throughout the season. This study demonstrates that UNIFI.GrapeML could guide inter-row management within vineyards under future climates, optimizing production and mitigating the environmental impact of viticulture.