A global meta-analysis of fruit tree yield and water use efficiency under deficit irrigation

Economical fruit trees are a kind of forest with great economic and ecological benefits, which has become an important cash source of many rural household incomes. However, the shortage of water resources has limited their development. Deficit irrigation (DI) is a novel water-saving irrigation method, but there is a risk of yield reduction in practice. Therefore, a meta-analysis was conducted to quantitatively analyze the impact of DI on fruit yield and water use efficiency (WUE) to explore the most suitable DI strategy for fruit trees. Overall, compared to full irrigation, DI decreased the fruit yield by 6.05% and increased WUE by 5.05%. However, the effectiveness of DI depended on DI factors, fruit tree varieties and environmental factors. In order to achieve a win-win goal of water-saving and yield increasing, a Win-Win analysis was conducted on collected data. It was found that DI was suitable for drought-tolerant tree varieties in the arid region with medium-textured and large bulk density soil. Adopting subsurface irrigation methods for low or moderate deficit (Irrigation limit ＞55%θf) before the fruit growth stage (i.e., bud burst to leafing stage and flowering to fruit set stage) was recommended. Our findings can provide implications for applying DI to fruit trees. •Deficit irrigation decreased fruit tree yield (6.05%) and increased WUE (5.05%) compared to full irrigation.•DI is suitable for drought-tolerant tree varieties in the arid region with medium soil texture and large bulk density.•DI performed better adopting subsurface irrigation methods for low or moderate deficit before the fruit growth stage•51.11% of data was observed in Win-Win situation.