Modified flue gas desulfurization residue (MFGDR) – a new type of acidic soil ameliorant and its effect on rice planting

Compared with solid waste landfill, cleaner production is an effective way to reduce solid waste all over the world. In this study, a modified flue gas desulfurization residue (MFGDR) was prepared and used to ameliorate acidic soil. The MFGDR was prepared by calcining a mixture of dry/semi-dry flue gas desulfurization residue, potassium feldspar and/or limestone powder in a definite molar ratio. The MFGDR, rich in K, Ca, Mg, Si and other micronutrients, which are lack in acidic soil. Application of the MFGDR was effective in raising soil pH, increasing soil available P, K, Ca, Mg and Si, and decreasing available Cd and Pb concentrations in soil. Growth of rice was significantly increased by the MFGDR application, comparing with the untreated control, straw yield and grain yield of rice were increased by 11.2–29.2% and 16.9–26.0%, respectively. Concentrations of Hg, As and Pb in rice grain were significantly decreased, after the MFGDR application. The MFGDR can be used as an ideal soil ameliorant to ameliorate acidic soil, especially for acidic soil wildly distributing in South China. The agricultural application of the MFGDR can effectively solve the FGD residue landfill problem, and the relevant regenerative purpose was also realized.