The coastal regions of the Jiangsu Province have abundant tidal flat resources. Tidal flat reclamation has supported vast land backup resources and provided land primarily for farming. Soil analyses were carried out to investigate physicochemical properties of the farmland soil and changes in wheat productions at reclaimed areas in Dongtai County over the 60-year period. The results demonstrated the following: (1) In general, during 58 years of cultivation, soil underwent desalination, dealkalization, and nutrients accumulation, soil electronic conductivity (EC_1:5) and pH_1:2.5 decreased from 5.29 dS/m and 8.76 before cultivation to 0.11 dS/m and 7.93 after that, respectively, and soil organic matter and total nitrogen increased from 2.64 g/kg and 0.15 g/kg to 13.72 g/kg and 1.12 g/kg, respectively; (2) Alkali-hydrolysable nitrogen (AH-N), available phosphorus (AP), and available potassium (AK) were strongly affected by fertilization and crop growth; AH-N and AP dropped after initial increase, whereas AK levels continuously decreased; (3) Soil carbon/nitrogen ratio and cation exchange capacity fluctuated sharply between 15 and 53 years of cultivation, reflecting the vulnerability of soil at this region. Studied physicochemical properties revealed that the soil at a depth of more than 20 cm was affected after 53 years of cultivation with the exception of AK; (4) With the improvement of soil environment, there were three stages in wheat production increase: high-speed increase (0-15 years), fluctuation in the production (15-53 years), and stable high production (over 53 years); wheat can reach stable production of this cultivar (Yangmai-16) after 53 years. Although heightened agricultural development greatly enhanced soil quality and wheat production, it also caused dramatic changes and fluctuations in soil environment triggering ecosystem problems; hence, the correlation between chemical fertilization and wheat production should be carefully assessed.