Drip irrigation in agricultural saline-alkali land controls soil salinity and improves crop yield: Evidence from a global meta-analysis

Saline-alkali land, a precious candidate arable land resources, plays a critical role in achieving agricultural sustainabil-ity. Drip irrigation (DI) is an effective method for rationalizing of saline-alkali land. Nevertheless, the inapposite appli-cation of DI increases the risk of secondary salinization, significantly leading to severe soil degradation and yield decline. In this study, we conducted a meta-analysis to quantify the impacts of DI on soil salinity and crop yield to de-termine the appropriate DI management strategies for an irrigated agricultural system in saline-alkali land. The results showed that DI generally decreased soil salinity in the root zone by 37.7 % and increased crop yield by 37.4 % relative to flooding irrigation (FI). Drip emitters with a flow rate of 2-4 L h-1 were recommended to obtain positive effects on soil salinity control and agricultural production when an irrigation quota was below 50 % crop evapotranspiration (ETc), and the salinity of irrigation water was between 0.7 and 2 dS m-1. Further, we also found that drip-irrigated cotton had a higher yield on fine-textured saline soils. Our study provides scientific recommendations for applying DI technology worldwide in the saline-alkali land.

Automated summary

Drip irrigation is an effective method for reducing soil salinity and increasing crop yield in saline-alkali land. Drip emitters with a flow rate of 2-4 L h-1 are recommended for irrigation quotas below 50% and irrigation water salinity between 0.7 and 2 dS m-1. Cotton crops benefit greatly from drip irrigation on fine-textured saline soils.