Attenuating the negative effects of irrigation with saline water on cucumber (Cucumis sativus L.) by application of straw biological-reactor

• Straw biological-reactor (SBR) decreased salt accumulation in the soil.
• SBR improved soil chemical properties in the root zone of cucumber.
• SBR reduced the negative effects of saline water on cucumber growth.
• SBR may be used to enhance crop growth under salinity conditions.

The shortage of high-quality water resources has become a major limiting factor for agricultural development in China, leading to the use of low-quality water resources (e.g., saline water) for crop irrigation. However, irrigation with low-quality water often results in negative effects on plant growth. We conducted an experiment under greenhouse conditions carried out over two growing seasons to investigate the effects of straw biological-reactor (SBR) application on soil properties, cucumber growth, and fruit yield and quality under saline (NaCl) water irrigation. Soils were treated with/without SBR, saline water and their combination. In general, under non-SBR conditions, soils irrigated with saline water showed significantly higher salinity, Na+ concentration and pH in the main root zone (0–40 cm) of cucumber, but significantly lower plant biomass and cucumber fruit yield, when compared to soils irrigated with non-saline water. However, under saline water irrigation conditions, soils treated with SBR showed significantly lower salinity, Na+ concentration and pH in the main root zone of cucumber, and significantly higher plant biomass and cucumber fruit yield, when compared to untreated soils. Additionally, saline water irrigation decreased total soluble sugars, titratable acidity and vitamin C in cucumber fruit. In contrast, the negative effects of saline water on fruit quality were significantly reduced by SBR application. Our results suggested that the application of SBR could not only enhance plant growth, but also improve fruit quality under saline water irrigation.