Vineyard cover cropping is a cultural practice widely used in many of the world’s winegrowing regions
being one of the most recommended practices to face climate changes and to promote vineyard
environmental sustainability. The benefits of using cover crops are many ranging from environmental
protection (e.g. control of soil erosion, enhancement of soil structure and biodiversity, sequestering
carbon) to vineyard management, including control of vigor and improvement of berry composition.
Despite those potential benefits, the adoption of cover crops in Mediterranean non-irrigated vineyards has
been limited by the concern of excessive water competition between cover crops and vines. However the
level of this competition should be better understood as in warm and dry terroirs, like the case of
Mediterranean winegrowing regions, water competition by the cover crops is effective mainly during
spring. During summer, the almost absence or rainfall induces the dry out of the sward vegetation which
residues became dead mulch that can even reduce soil evaporation. Furthermore, some research has also
demonstrated that, after some years of competition with swards, the vines were able to develop deeper
roots, therefore increasing the capacity for water extraction from deeper soil layers.
In order to further elucidate the above mentioned topics, in this paper data on water use and grapevine
performance obtained in three floor management experiments (soil tillage vs. inter-row swards), carried
out in three different winegrowing regions of the Mediterranean Portugal (covering rainfed and irrigated
vineyards), will be presented. Discussion will be focus on water competition by the swards and
corresponding effects on grapevine vigor, yield and berry composition. The effect of terroir on grapevine
responses will be also underlined. From the data presented it can be concluded that cover crops is a
vineyard management practice that can have a positive influence on water use efficiency, either by
preventing vine excessive vigor when water is fully available during spring or by maximizing the volume
of soil explored by vine roots through the enhancement of the exploitation of soil water reserves into
deeper layers. However, in the case of low vigor vineyards located in dry terroirs, the degree of water
competition between cover crops and vine must be carefully monitored and managed (e.g. by increasing
mowing frequency, reducing the sward strip and/or choosing less competitive species) and adjustments in
conventional irrigation management are necessary in order to avoid detrimental effects on grapevine yield
and longevity.info:eu-repo/semantics/publishedVersio
