Effects of mulching and sub-surface irrigation on vine growth, berry sugar content and water use of grapevines

The objective of efficient water management in vineyards is to save water, increase yield, and improve berry quality. So far, the effects of rice-straw mulching (M) and/or sub-surface seeper hose irrigation (SS) on grapevine's performance and water use are not clear. An experiment was conducted on ‘Gros Colman’ grapevine (Vitis vinifera L.) in a greenhouse using four weighing lysimeters. Four treatments: M combined with SS (MSS); no-mulch combined with SS (SS); no-mulch combined with surface irrigation (S); M combined with S (MS), were compared. Results showed that the higher yield, longer shoot length, and larger berry for MS could be related to the relatively higher moisture at top soil compared to other treatments. MS gave the highest water use efficiency (WUE), followed by MSS and SS, while S was the last efficient among the four treatments. Compared with SS, the berry diameter, fresh yield, WUE, and berry sugar concentration for MS were enhanced by 2.8mm, 271.5g/tree, 33% and 15%, respectively. MSS gave a higher berry sugar concentration than MS on most sampling days, which could be attributed to the lower moisture and the higher average soil temperature (Ts) in the top soil layer. Mulching combined with surface irrigation (MS) is a useful technique for maximizing water use efficiency.