L'inerbimento nell'ecosistema vigneto: confronto di metodologie di misura del consumo idrico del prato e risposta allo sfalcio

Abstract

Water resources management will become increasingly important in agriculture as global warming takes place. Cover crop is largely used in viticultural areas based on the many positive agronomic and environmental benefits it provides. However, it is not clear what effect the cover crop can have on water use in the vineyard. This study is designed to develop a further understanding of the role cover crops play in total water use in the vineyard and develop our understanding of the potential use of cover crops as a water management tool. Two techniques were used to measure cover crop water use, the mini-lysimeters and a portable open chamber and data from both was compared to reference evapotranspiration (ETo) (FAO guidelines). While the mini-lysimeters seemed to be limited in their ability to accurately represent the water use of the surrounding soil, the open chamber method is a reliable and suitable instrument to be used for the accurate measurement of evapotranspiration. Further, the relationship between vineyard grass water use and the contributing environmental factors thought to influence water use were analyzed. A strong relationship between total available radiation and cover crop evapotranspiration was found suggesting the possibility of an indirect method of evapotranspiration measurement in a vineyard grass cover crop. Mowing the cover crop was determined to significantly effect transpiration as shown by both the mini-lysimeter and open chamber, however, the reduction was largely dependent on the growth rate of the grass.