J.M. Escalona

Improving water use efficiency of vineyards in semi-arid regions. A review

Water is critical for viticulture sustainability since grape production, quality and economic viability are largely dependent on water availability. The total water consumption of vineyards, 300 to 700xa0mm, is generally higher than the annual average precipitation in many viticultural areas, which induces a risk for sustainability of vineyards. Improving vineyard water use efficiency (WUE) is therefore crucial for a sustainable viticulture industry in semi-arid regions. Increased sustainability of water resources for vineyards can be achieved using both agronomical technology and cultivar selection. Here, we review advances in grapevine water use efficiency related to changes in agronomical practices and genetic improvements. Agronomical practices focus on increasing green water use by increasing soil water storage capacity, reducing direct soil water loss, or limiting early transpiration losses. Cover crops for semi-arid areas show a favorable effect, but careful management is needed to avoid excessive water consumption by the cover crop. Canopy management practices to reduce excessive water use are also analyzed. This is a genetic based review focused on identifying cultivars with higher WUE.

Influence of water availability and grapevine phenological stage on the spatial variation in soil respiration

Background and Aims n nAn understanding of spatial variation in soil respiration is critical to determining the carbon balance in grapevines. The effect of soil water content on soil respiration during different phenological stages in two grapevine cultivars, Grenache and Tempranillo, was studied over two seasons (2013 and 2014). nMethods and Results n nSoil respiration was measured from five locations confined to within and between rows of vines at five phenological stages between budburst and postharvest under irrigated and non-irrigated conditions. Vine phenology influenced the in-row soil CO2 efflux to a greater extent than the between-row CO2 efflux, while irrigation resulted in in-row soil respiration 65% higher than that of the between-row positions. In contrast, the flux from the in-row positions of the non-irrigated treatment was only 25% higher than that of the between-row positions. Soil moisture and vine phenological stages appeared to have a greater influence on soil respiration than soil temperature. nConclusions n nSignificant correlations existed among soil respiration, irrigation and the vine phenological stages. Soil respiration increased from budburst to pea-size berry stage; thereafter, it decreased until the ripening stage before increasing again during the postharvest stage. nSignificance of the Study n nThe study showed that soil water availability and vine phenology play an important role in influencing soil respiration under field conditions.