Taken the severe saline-alkali soil of the Yellow River Delta as research soil sample

vertical one-dimensional ponding infiltration experiments were conducted in the laboratory to study the change laws of cumulative infiltration

wetting front depth and infiltration rate with time

soil desalting depth

and desalting rate after irrigation under five distribution proportions between brackish and fresh water. The results showed that: (1) After the first round of brackish water infiltration finished

compared with all brackish water irrigation at the same time

cumulative infiltration

wetting front depth and infiltration rate obviously declined after the second round of fresh water irrigation

in addition

the more fresh water used for the irrigation

the more obviously these parameters declined

but these parameters were still significantly higher than those for all fresh water irrigation. (2) Cumulative infiltration had good linear relationship with wetting front depth

with all coefficients of determination of regression equations being greater than 0.99. Kostiakov formula was more suitable for describing the relationship between infiltration rate and time than Green-Ampt model and Philip model. (3) Distribution proportion between brackish and fresh water had slight effect on soil desalting depth

but it had significant effect on desalting rate within soil desalting depth. Soil desalting rate under successive brackish and fresh water irrigation was far greater than all brackish water irrigation and was slightly different from that under all fresh water irrigation within a certain depth range

but it was obviously less than that under all fresh water irrigation and essentially equal to that under all brackish water irrigation when soil layer depth further increased.