Carboxymethyl cellulose as a new soil conditioner improves water retention capacity of saline soils and increases crop yields

Abstract Traditional soil amendments are falling short in dealing with rising soil salinization and alkalization issues. Discovering new materials and methods for efficient water retention and salt control is vital for the development and sustainable use of saline‐alkaline soils. This study comprehensively assesses how carboxymethyl cellulose (CMC) at different application rates retains water and controls salt, and its effect on maize growth. It uses soil column experiments, electron microscopy analysis, germination assays, and field trials. Soil column experiments show CMC boosts cumulative soil infiltration by 24.64% to 68.11% and cuts evaporation by 14.35% to 34.85%. Medium to high doses enhance water retention. SEM reveals CMC improves soil structure and porosity. Germination assays find low to medium CMC concentrations do not affect germination rate but boost vigour index and plant height, while high concentrations inhibit growth. Integrating CMC into drip irrigation increases soil moisture, improves infiltration, and raises maize evapotranspiration and grain yield. CMC is an effective novel soil amendment for saline‐alkaline soils, promoting maize growth and yield. Yet, long‐term effects on soil health and environmental impacts need further study for safety and efficacy in agriculture.