In order to explore the effects of different irrigation modes on the improvement of severe saline soil in Hetao Irrigation District

this experiment set up three treatments of straw deep burial (SL)

gypsum + organic fertilizer (SF) and control (CK)

and the distribution characteristics of soil salinity in the 0-70 cm profile of the soil were studied. The results showed that under different irrigation patterns

SL and SF effectively reduced soil pH in 0-15 cm soil layer

the pH decreased continuously with the extension of the treatment time and the increasing of improvement depth. Compared with CK

the pH of SL and SF under drip irrigation decreased by 0.35 and 0.49

respectively

and that of SL and SF under yellow river irrigation decreased by 0.42 and 1.33

respectively

while irrigation mode had little effect on 30-70 cm soil layer. The alkalinity of SF decreased by 43% in the second year and that of SL decreased by 40%

drip irrigation was beneficial to the reduction of alkalinity. In terms of inhibiting salt accumulation

SL and SF could effectively inhibit the aggregation of salt in 0-15 cm soil layer. Compared with CK

the salt of SL and SF under yellow river irrigation decreased by 13.60% and 7.70%

respectively

and that under drip irrigation decreased by 31.60% and 6.90%

respectively. SL had significant salt inhibition effect. The soil salt-based ions showed that the SL and SF significantly reduced the contents of Na+ and HCO3- in 0-15 cm soil layer under different irrigation modes

the reduction ratio of drip irrigation was higher than that of yellow river irrigation

and the effect was more obvious with the extension of the improvement time. While there was no significant change in 15-70 cm soil layer. The application of gypsum and organic fertilizer increased the contents of SO42-

Ca2+ and Cl-in 0-70 cm soil layer. Through comparative analysis

for the treatment of severe saline soil in Hetao Irrigation Area

both deep burying and gypsum + organic fertilizer could effectively inhibit salt accumulation in severe saline soil

reduce pH and alkalinity. Overall

the improvement effect of gypsum+ organic fertilizer under drip irrigation mode was better than the deep straw burial.