Cover crop water use in relation to vineyard floor management practices

The aim of our study was to compare soil evaporation (E_s) versus cover crop (Festuca arundinacea var. barfelix) evapotranspiration (ET_cc) within a vineyard ecosystem and to investigate the effect of mowing in reducing cover crop evapotranspiration, and, hence, its below-ground competitiveness. The study was carried out in a 2-year-old Sangiovese (Vitis vinifera L.) vineyard, grafted to SO4, in Bologna, Italy. Mini-lysimeters and a portable gas-exchange chamber system were used to investigate cover crop evapotranspiration in relation to mowing and bare soil management practices. Our results show that, immediately after mowing, ET_cc markedly decreased, with the percentage of reduction ranging from 35 to 49%, depending on the amount of clipped biomass. The extent of the ET_cc reduction decreased over time as the cover crop regrew. Over the 28-day period following the mowing, soil evaporation was 35 and 48% lower than mowed and unmowed cover crop evapotranspiration, respectively. This study shows that mowing could be used as a water management strategy to decrease vine cover crop competition over a short time period.