Soil salinization is a global environmental problem affecting crop growth and yield. However, despite the widespread use of Cyperus esculentus (C. esculentus) to remediate sandy saline soils undergoing desertification, the effect of different soil amendments on C. esculentus in saline soils remains unexplored. Therefore, a field experiment was conducted from 2023 to 2024 using four four treatments (CK, untreated control group; MA, microbial agent; AS, ammonium sulfate; HA, humic acid. The effects on soil chemical properties, crop yield, nutrient content, and quality were assessed at two stages in 2024 (T1, seedling stage on July 1; T2, maturity stage on September 1). The results showed that in both T1 and T2 stages, MA, AS and HA treatments had significantly lower soil pH and increased soil nutrient content than the control, with the MA treatment being the most significant difference. Compared with CK, MA increased the yield by 73.37% and 57.87% at each time point, respectively. The MA treatment primarily acted via significantly decreasing soil pH and TS content while simultaneously increasing SOC content, which in turn significantly increased total nitrogen, total phosphorus, total potassium and organic carbon content in C. esculentus leaves, roots and tubers. These changes in nutrient content in turn improved soluble protein and starch content. Overall, the combined application of MA promoted the growth and nutrient uptake of C. esculentus by improving quality of saline soils. Our study provides a new reference for the effective use of C. esculentus as a conservation tool in sandy saline areas suffering desertification.