| To investigate the application effects of different soil amendments on saline soil in arid areas, a single factor randomized block experiment was conducted, with no amendment applied(T0) as the control, to explore the effects of six amendments, namely fly ash(T1), biochar(T2), ordinary organic fertilizer(T3), furfural residue(T4), earthworm castings(T5), and humic acid(T6), applied alone, as well as composite amendments of fly ash+organic fertilizer(T7), fly ash+furfural residue(T8), biochar+furfural residue(T9), and earthworm castings+humic acid(T10) applied at half of the single application rate, on soil salinization characteristics and oat salt accumulation. The results showed that compared with T0 treatment, the contents of Na+, HCO3-, Cl-, and SO42- in soil decreased by 37.18%-67.83%, 35.25%-78.10%, 45.16%-69.51%, and 6.60%-13.94%, respectively, under T1-T10 treatment, while K+, Ca2+, and Mg2+ contents increased. The total salt content and sodium adsorption ratio(SAR) of the soil decreased by 8.41%-15.97% and 41.94%-69.70%, respectively. After the application of amendments, the pH of the soil decreased to varying degrees. The T1 and T2 treatments had no significant effect on reducing the soil pH due to the alkalinity of the amendments themselves. The soil pH under the T3-T10 treatments decreased by 5.09% to 8.61%, compared with that under T0 treatment. The combined application of amendments showed better reduction in Na+, HCO3-, Cl-, SO42- contents, total salt content, SAR, and pH than single application did, with T7 treatment showing the best reduction effect. The application of amendments increased the forage yield, aboveground salt content, and salt accumulation of oats. Except for T6 treatment, the salt content of oats under other treatments increased by 1.43% to 3.52% compared with that under T0 treatment. The salt accumulation of oats treated with T1-T10 increased by 14.92%-34.64%, and the combined application showed greater increase in salt accumulation than the single application did. The application of amendments accelerated the desalination of topsoil. The desalination rate of T1-T10 treatments was 5-9 times higher than that of T0 treatment, and the desalination rate of T7 treatment increased by 4.99%-7.41% compared with T1-T5 treatments. In summary, the single application and four combination applications of the tested amendments all had the effect of reducing the salinity and alkalinity of the saline soil layer in the experimental area, and improving the biological salt excretion effect of oats. The combination of fly ash and ordinary organic fertilizer has the best effect on reducing the degree of soil salinization in the plow layer. |