Highly dispersed hard saline–sodic soils are important agricultural land reserves in theworld. These soils are difficult to be ameliorated by conventional amendments because of poor soil properties. The objectives of this study are to screen a highly efficient inorganic polymer soil amendment using laboratory experiments and to evaluate its effectiveness in soil improvements and grain yield promotion under paddy field conditions using field experiments. Compared with control soils cultivated with rice for one year without PAFS treatment, the pH of the 0–8 cm and 8–16cm layers of PAFS-treated soil
decreased from 10.70 and 10.75 to 8.94 and 9.99, respectively, soil CaCO3 contents decreased by 29.49% and 16.19%, respectively, and contents of silt-plus-clay particles decreased by 46.06% and 14.55%, respectively. Soil saturated hydraulic conductivity increased from 0.05mmd1 to 40.01mmd1 and soil bulk density decreased from 1.55 g cm3 to 1.29 g cm3 in the 0–8 cm soil layer. Soil exchangeable Na+, exchangeable sodium percentage (ESP), and salinity (ECe) in the 0–8 cm soil layer were reduced by 61.92%, 63.23%, and 45.61%, respectively; in the 8–16cm soil layer, the corresponding values decreased by 34.91%, 34.57%, and 37.47%, respectively. Rice yields with PAFS application in the first year of cultivation were as high as 4.66 t ha1. By contrast, rice yields without PAFS applicationwere only 0.83 t ha1 in plots
cultivated with rice for one year and 1.55 t ha1 in plots cultivated with rice for two years. Therefore, PAFS is effective for amending hard sodic soils.