Soil water-salt control and yield improvement under the effect of compound control in saline soil of the Yellow River Delta, China

Soil salinization and water shortage restrict the utilization of saline soil resources in the Yellow River Delta, China (YRD). As such, soil water and salt management are two methods for the saline soil reclamation in this area. In this study, a two-year field experiment was conducted to investigate the effects of compound control on the rules of water and salt movement in salt-affected field, and their effect on cotton yield, which were combined by plastic film mulch and buried wood fibre layer (FM+BL). Hydrus-2D was used to analyse their spatial and temporal change. Results showed that soil water at different observation positions were maintained above 0.15 cm³ cm⁻³ under film mulch, which was higher than that in bare ground (BG), and the closer to the topsoil the greater difference between FM+BL and BG, especially in 2020. FM+BL controlled soil water stress and improved water use efficiency during the whole growing season both in 2019 and 2020. FM+BL invariably and significantly controlled the salt content of the upper 60 cm depth, which was lower than 2.00 g kg⁻¹ during the whole growing season. Furthermore, soil salt contents under film mulch in the upper 30 cm depths were significantly reduced for the high soil water contents. Thus, soil salt content of 0–60 cm layer responded to the heavy rainfall events positively, soil salinity decreased as a whole along with the process of rainfall under the effect of FM+BL. FM+BL has a significant effect on crop growth and yield improvement, the average yields were 1163.7 and 1301.7 kg ka⁻¹ in 2019 and 2020, respectively. Therefore, FM+BL could be an efficient way for soil water conservation, salt accumulation interruption and cotton yield increasing in the YRD.