Characteristics of soil salinity and salt ions distribution in salt-affected field under mulch-drip irrigation in different planting years

In order to investigate the long-term effect of mulch-drip irrigation on the chemical properties of salt-affected soils by the method of time-space transformation. The characteristics of salinity and salt ions distribution in 0～150 cm soil profile in the fields with corn planted for one year and two years. At the same time, the uncropped saline waste land adjacent to the experimental site was taken as the control. The results show that the soil salinity, contents of individual salt ions, pH value, the ratio of Cl^- to SO₄^2- and sodium adsorption ratio(SAR) in 0～40 cm layer decreased gradually with the increase of planting years when the soil matric potential at 20 cm depth immediately under emitter is maintained higher than -10 kPa under mulch- drip irrigation. It indicates that soil environment is becoming better with the increase of planting years in 0～40 cm layer. Compared with uncropped saline waste land, contents of chloride and sodium, the ratio of Cl^- to SO₄^2- and SAR in the layer of below 40 cm under mulch-drip irrigation increase.