Effects of partially substituting freshwater with saline water in irrigation on wheat seedlings and soil properties of coastal saline-alkali soils under drought

ZHANG Hui; GAO Zian; LI Xichen; CHAO Ying; LOU Yanhong; ZHUGE Yuping; HAN Fei; LI Yaping; WANG Hui; PAN Hong; YANG Quangang

doi:10.13522/j.cnki.ggps.2025322

Abstract：[Objective]In arid and semi-arid regions of the Yellow River Delta,where freshwater is scarce and saline water is abundant,partially substituting freshwater with saline water in irrigation is a potential strategy for agriculture.However,excessive use of saline water negatively affects crops and soil health.This study experimentally investigated the safe limit saline water substitution ratio for irrigating wheat seedlings.[Method]The experiment was conducted in pots filled with a moderately saline soil collected from the Yellow River Delta.It consisted of eight treatments:sufficient irrigation with freshwater(CK1),water stress+irrigation with freshwater(CK2),and water stress+substituting 1/6(W1),1/3(W2),1/2(W3),2/3(W4),5/6(W5),and 6/6(W6)of the freshwater used in CK2.During the experiment,the growth and physiological traits of the wheat seedlings,as well as soil properties were measured in each treatment.[Result]①Compared with CK2,treatments W1,W2 and W3 did not show significant differences in plant height,stem diameter,root-shoot ratio,root surface area,and the activities of urease,sucrase and catalase.②Treatments W4,W5 and W6 not only resulted in significant decreases in fresh and dry weight,total root length,root projected area,root surface area,and root tip number,but also reduced water use efficiency,chlorophyll content,leaf glutathione content,and the activities of peroxidase and superoxide dismutase.③Soil salt content increased as the saline water substitution ratio increased.Compared with CK2,W4-W6 increased the soil salt content by more than 64.93％.[Conclusion]Increasing the saline water substitution ratio in irrigation resulted in a significant decrease in wheat growth and deterioration of soil properties.Considering the combined effects of saline water on wheat and soil,substituting less than one-half of freshwater with saline water is the save limit for irrigating wheat seedlings.