Waste to wealth: Waste liquid promotes rice growth in soda saline-alkali soil by improving Desulfocapsaceae abundance

Lignocellulose sulfuric acid pretreatment is widely utilized in many industrial fields, but its waste liquid endangers the environment. While, the waste liquid has potential to promote plant growth in saline-alkali soil due to its strong acidity and high organic matter content. Therefore, the waste liquid was innovatively used to promote rice growth in soda saline-alkali soil, and a novel growth promotion mechanism revealed. This waste liquid promotes rice growth by lowering pH and optimizing microbial community of rice rhizosphere, especially increasing Desulfocapsaceae abundance. Desulfocapsaceae reduced sulfate into H 2 S, which increased the content of abscisic acid (ABA) and betaine in rice, thereby promoting rice growth in saline-alkali soil. The waste liquid increases rice yield in soda saline-alkali land by about 17 %. This study addresses two challenges simultaneously: the sustainable and high value-added management of industrial wastewater and the enhancement of crop growth in challenging saline-alkali soils. This study is of great significance to biomass energy utilization and saline-alkali repair.