To examine the impacts of various straw mulching techniques, this study used the indoor soil column test as the primary research method and the field test as the validation test on the salinity dynamics of saline and alkaline soils. The experiment in this study was designed with five treatments: SC means for straw covered on the soil surface; DB means for straw buried 40 cm below the soil surface; S1D1, S2D1, and S1D2 represent the ratio of soil surface cover to the amount of straw buried 40 cm below the soil surface as 1:1, 2:1, and 1:2, respectively. The results of the indoor soil column test showed that all kinds of straw mulching techniques could effectively reduce soil moisture evaporation, and the straw mulching and deep burial mode was more effective: after 45 days of evaporation, compared with that of CK, the cumulative evaporation of soil moisture were reduced by 29.61%, 27.49%, 37.87%, 65.85%, and 54.58% for SC, DB, S1D1, S2D1, and S1D2, respectively; the straw mulching and deep burial mode could reduce the soil evaporation intensity more effectively than the single-layer straw mulching mode: the mean soil evaporation rates of CK, SC, DB, S1D1, S2D1 and S1D2 after 45 days of evaporation were 1.27 mm/day, 0.90 mm/day, 0.92 mm/day, 0.80 mm/day, 0.43 mm/day, and 0.58 mm/day; various straw mulching techniques could inhibit the accumulation of salts in the surface soil and effectively regulate the distribution of salts in the soil profile, among which the straw mulching and deep burial mode had the best effect of salinity suppression: after 30 days of evaporation, the re-salinization levels of the 0–40 cm soil layer of SC, DB, S1D1, S2D1, and S1D2 were reduced by 66.78%, 43.08%, 33.95%, 92.04% and 45.94% compared with that in the CK, respectively; there was a significant positive correlation between cumulative evaporation of soil moisture and cumulative soil salinity, which implied that cumulative soil salinity increased with the increase in cumulative evaporation of soil moisture. The results of the field experiment justified the results of the indoor soil column test: after four months of evaporation, the field moisture contents of CK, SC, DB, S1D1, S2D1, and S1D2 in the 0–20 cm soil layer were 14.77%, 3.51%, 15.10%, 15.26%, 18.73%, and 2.94%, respectively; during the experimental period, the salt inhibition rate of SC, DB, S1D1, S2D1 and S1D2 in 0–20 cm soil layer were 35.46%, 44.76%, 50.98%, 54.80% and 37.30%, respectively. Therefore, in a comprehensive view, S2D1 treatment had the best effect of salt and vapor suppression on saline soil. This study is of great significance for the resource utilization of straw waste, the improvement of water utilization and efficiency, and the management of soil salinization.

This study chose the indoor soil column test as the main method and the field test as the validation test to investigate the effects of various straw mulching techniques (surface, deep and straw mulching + deep burial) on evaporation and salt dynamics in saline soils. The results showed that straw mulching treatment could effectively reduce soil water evaporation, promote desalination in the stage of leaching infiltration and alleviate salt return in the stage of water evaporation, and the effect of straw mulching + deep burial treatment was better than that of single-layer straw mulching treatment. The indoor soil column test showed that S2D1 treatment (a 2:1 ratio of soil surface cover to the amount of straw buried 40cm below the soil surface) had the best effect on the suppression of soil moisture evaporation, and the cumulative evaporation of soil moisture was reduced by 65.85% compared with that of the CK, and the rate of salinity return in the evaporation stage was effectively reduced by 92.04% compared with that of the CK. In addition, there is a significant positive correlation between cumulative evaporation of soil moisture and cumulative soil salinity, which implies that cumulative soil salinity increases with cu-mulative evaporation of soil moisture. The results of the field experiment were consistent with the soil column test, and the S2D1 treatment was able to maintain high soil moisture content in all soil layers in all periods of the experiment and kept soil salinity in the 0-40 cm soil layer at a low level. However, in the 40-80 cm soil layer, the soil salinity suppression effect of DB treatment (straw buried at 40 cm below soil surface) was the best. So in summary, the S2D1 treatment had the best salinity and evapo-transpiration suppression effect in saline soils. This study is of great significance for the resource uti-lization of straw waste, improvement of water utilization and efficiency, and soil salinization manage-ment.

This study targets key challenges in ameliorating the plow-layer soil of coastal saline soils. A field experiment under a wheat–maize rotation was established with six treatments: CK, control with no organic inputs; A1, 45 t ha⁻¹ organic manure; A2, 45 t ha⁻¹ organic manure + microbial inoculant; A3, 45 t ha⁻¹ organic manure + microbial inoculant + plastic-film mulching; A4, 90 t ha⁻¹ organic manure; and A5, 135 t ha⁻¹ organic manure. By applying high rates of organic manure alone or in combination with microbial inoculation and mulching, we aimed to strengthen soil water–salt regulation, improve plow-layer soil quality, and ultimately promote crop growth and yield formation. We further quantified treatment-induced shifts in soil physicochemical properties and linked them to crop growth and yield responses. The results indicated that, compared with CK, plow-layer soil organic carbon increased by 45.56% and 107.91% under A3 and A4, respectively, while soil salinity decreased by 70.57% and 67.42%. All manure-based treatments increased yield relative to CK, with the highest yields achieved under A3 and A4: wheat yield reached 7628.16 and 7888.01 kg ha⁻¹, and maize yield reached 8828.29 and 8716.01 kg ha⁻¹, respectively. Overall, high-rate organic manure—especially when integrated with microbial inoculation and plastic mulching—substantially enhanced soil fertility while alleviating salinity stress, resulting in an integrated “fertility build-up–salinity reduction–yield enhancement” amelioration effect. This technology package offers a feasible pathway for improving coastal saline farmland and stabilizing productivity under rotation systems, with strong potential for further on-farm demonstration and wider adoption.