The current water scarcity threatens the sustainable production of paddy fields. The application of superabsorbent (SAP) prepared by biodegradable materials is of significant importance. The main objective of this research is to consider the effect of starch-SAP (S-SAP) on water use efficiency for rice cultivation and compare that with commercial-SAP (C-SAP) in greenhouse conditions with a factorial completely randomized design with two factors. The first factor was drought stress at three levels and the second factor was SAP application at 11 levels. The S-SAP had high performance for water absorption and in turn the SEM, FT-IR and TGA results showed that the polyacrylic acid chain has been successfully bonded to the starch backbone leading the highly porous S-SAP. The greenhouse results significantly indicated that the drought stress, SAP (C-SAP and S-SAP) levels and interaction effects were effective on the water use efficiency. The application of 0.1% of the SAP improved the maximum water absorption capacity up to 42.96% enhancing the water use efficiency up to 11% compared with the control. Overall, the use of S-SAP was effective in elevating the water use efficiency in rice cultivation and the application of 4gr kg^-1 N-enriched S-SAP was the optimum application rate for calcareous paddy fields.