Management of saline-alkali sandy soils by amphoteric lignin-based sand fixation.

The management of deserts and saline-alkali sandy soils requires a large number of efficient and economical sand-fixing agent. However, the preparation of sand-fixing materials with excellent overall performance is still a great challenge. In this work, a sand-fixing agent with amphiphilic polyelectrolyte (ASL-PVA) was prepared by graft copolymerisation of sodium lignosulfonate (SL) with cationic (DMDAAC) and polyvinyl alcohol (PVA). The sand fixation of ASL-PVA was evaluated using typical saline-alkali sandy soils from the desert topsoil of Inner Mongolia, China. The anionic, cationic and benzene ring structure of ASL-PVA give it excellent water retention, adhesion and degradation resistance in saline-alkali sandy soils. The antipolyelectrolyte effect between ASL-PVA and soluble salt ions can improve its salt tolerance. Moreover, lignin as a precursor of humus makes ASL-PVA also has the properties of improving the physicochemical properties of saline-alkali sandy soils and promoting plant growth. The ASL-PVA sand-fixing agent demonstrates promising application potential in saline-alkali sandy soil improvement and desert restoration.