Abstract: We explored the effects of different irrigation modes with reclaimed water from wine production on soil condition, microbial community structure, and grape growth in vineyards. The optional method of reclaimed water utilization was determined to provide empirical evidence that could assist the recycling of wastewater from wine production at the eastern foot of Helan Mountain, Ningxia, China. We conducted a field experiment with three-year-old grapevines (Vitis vinifera cv. Merlot) and four treatments: clean water irrigation (CI, control), alternate irrigation with fresh clean water and reclaimed water (AI), mixed irrigation with fresh clean water and reclaimed water (1∶1, MI), and reclaimed water irrigation (RI). Soil physicochemical properties, rhizosphere bacterial diversity and community composition, as well as grape yield and quality were measured. Compared with the CI treatment, pH values of 0-80 cm soil layers were not significantly changed under different irrigation modes with reclaimed water. The electrical conductivity of 20-40 and 80-100 cm soil layers markedly increased under the MI treatment by 53.98% and 99.66%, respectively. There were no differences in soil organic carbon content among various irrigation treatments with reclaimed water. However, under the AI treatment, the total nitrogen and phosphorus contents of 0-20 cm soil layer dramatically increased by 38.46% and 39.94%, respectively, and the total phosphorus content of the 40-100 cm soil layers markedly increased by 32.88%-79.63%, compared with the CI treatment. Different irrigation modes had limited effects on soil available nutrients. The genus-level bacterial community composition of rhizosphere soils and its relationships with soil factors distinctly varied under the MI and RI treatments compared with the CI treatment. However, PCoA analysis revealed consistent results under the AI treatment with the CI treatment, and the relationships between soil environmental factors and microbial community composition did not change substantially. The yield components of wine grape and the soluble solid content, titratable acid content, and sugar-acid ratio of fruits had minor differences under various irrigation modes. In the wine-producing area of the eastern foot of Helan Mountain, the alternate irrigation mode with clean water and reclaimed water can convey benefits to regional water use efficiency, soil fertility, and sustainable grape production.

Key words: wine production, reclaimed water, irrigation, eastern foot of Helan Mountain.