Effect of shifting sand burial on soil evaporation and moisture–salt distribution in a hyper-arid desert

It is a serious threat for the sustainable protection of the Taklimakan Desert Highway Shelterbelt (TDHS) from shifting sand burial. To explore the effects of shifting sand burial on soil evaporation, salt accumulation and their distribution, Micro-lysimeters were used under sand burial of different thickness (1, 3 and 5 cm) and particle size (<0.063, 0.063–0.20 and 0.20–2.00 mm). The results demonstrated that: (1) soil daily evaporation and accumulative evaporation decreased with the sand burial thickness, and thus evaporative inhibiting efficiency increased. Consequently, the soil water content increased with sand burial thickness (1.48–12.70%) than the control; (2) finer-textured (<0.063 mm) sand burial (0–2 cm depth) promoted soil evaporation and salt accumulation at topsoil, accumulative evaporation increased 5.1 mm and electrical conductivity (EC) of topsoil increased 13.30 dS m⁻¹ compared with the control; and (3) while topsoil EC decreased 1.65–6.46 dS m⁻¹ with the increase in sand burial thickness, soil EC beneath the sand burial interface showed a reverse trend. We concluded that shifting sand burial has obvious effects on soil water evaporation, salt accumulation and water-salt redistribution, and it could be considered to save water and reduce salt accumulation in arid desert areas like the TDHS with saline irrigation.