EFFECTS OF IMPROVEMENT MEASURES ON DESALTING HEAVY SALINE-ALKALI SOIL UNDER WINTER IRRIGATION IN SOUTHERN XINJIANG, CHINA

To identify effective improvement measures for the clay-containing interlayers of heavy saline-alkali soil in southern Xinjiang, China, this study focused on interlayer soil with heavy salinity and alkali content, examining the effects of various improvement techniques on soil salinity and desalting efficiency under consistent winter irrigation quotas from 2020 to 2023.Results showed that after the 2023 winter irrigation, following three rounds of irrigation, treatments G4, G7, G10 and CK1 reduced salinity from 11.37 to 3.35, 11.44 to 4.47, 8.81 to 1.54 and 13.50 to 7.17 gkg -1 , respectively.The G1 treatment decreased salinity from 11.25 to 1.17 gkg -1 after four winter irrigation sessions.Among the treatments, G1 and G10 exhibited the highest desalting rates at 89.60% and 82.52%, respectively, whereas the other treatments ranged from 50.08% to 75.91%.The CK1 and CK2 treatments achieved desalting rates of 51.48% and 47.87%, respectively.These findings demonstrate that improvement measures, such as deep tillage, ditching with sand irrigation and drilling with sand irrigation, effectively reduce the salt content of heavy saline-alkali soil.These techniques significantly enhance desalting efficiency, reducing salinity to a low level after three-four winter irrigation cycles.Considering the economic feasibility and practicality of the improvement measures, drilling and sand filling are recommended for the treatment of interlayercontaining heavy saline-alkali soil in the study area.