The soil oxidation-reduction potential, soil available nutrients and rice yield were low in cold spring paddy fields because of long-term flooding by cold spring water. A field experiment and laboratory analysis were performed to study the effects of different amendments on improving soil properties and rice growth. Experimental treatments were control, biomass charcoal, desulphurization ash, gypsum, calcium peroxide and silicon calcium fertilizer. The results showed that the application of biomass charcoal and gypsum reduced soil active reducing substances by 52% and 30%, respectively, and thus increased soil oxidation capacity evidently, compared with control. Application of biomass charcoal and gypsum also increased soil bacteria by 200% and 96%, respectively, and reduced the number of soil fungi by 16% and 10%, respectively, while soil available N was increased evidently. Application of desulphurization ash increased soil available P, soil available K and rice chlorophyll content by 83%, 50% and 3%, and the corresponding data were 83%, 13% and 5% for the treatment with gypsum applied. Consequently, the rice yield was increased by 13.0%, 10.1% and 5.1% due to application of gypsum, biomass charcoal and desulphurization ash. In conclusion, application of biomass charcoal, gypsum and desulphurization ash could reduce toxicity of soil reducing substances, increased soil microorganism activity, contents of soil available nutrients and rice yield.