Zhenqi Hu

and 3 more

Underground coal mining causes land subsidence, a large area of cultivated land is destroyed. The Yellow River interlayer filling reclamation technology is the powerful way to restore cultivated land. Understanding the mechanism of action of interlayers in reconstructed soil filled with Yellow River sediments is essential to achieving sustainable land management in the Yellow River regions. Column experiments and Field experiments were conducted to optimum of interlayers in reconstructed soil with Yellow River sediment for restoring subsided coal mined land. Our findings show that the inclusion of interlayers in the sediment reduced water leakage and moisture evaporation, and improved the water-holding capacity of the material in comparison to conventional reconstructed soil profile (Ck2). When the 30 cm thickness of interlayer, putting 2 interlayers in sediment (T6) was the optimal profile with the highest water-holding capacity. In comparison to CK2, the migration rate of wet front decreases by 32.16%, the cumulative evaporation decreases by 16.29%, the volumetric water content of filling layer (θ_fl) increases by 121.56%, and the water-holding coefficient (CWR) increases by 59.47%. It is also proved by field experiments. The wheat and maize yields of T6 improved 51.84% and 54.80%, respectively, as compared with CK2, that closer to undisturbed farmland (CK1). This study provides a valuable framework for subsided land reclamation regarding the method of placing interlayers into Yellow River sediment for enhancing water retention and productivity.