Amelioration of Acidic Soil Using the Calcined Product of Dry and Semi-Dry Desulfurization Residue with K-Feldspar: Plant and Soil Responses and Heavy Metal Assessment

In this study, a novel ameliorant, calcined by a mixture of dry and semi-dry desulfurization residue and K-feldspar, was used to ameliorate acidic crimson soil which was widely distributed in South China. Application rates of the ameliorant were 0, 3.4, 6.8, 10.2 mg per hectare (ha) sweet corn fields, respectively. The planting test lasted a season. The height and perimeter of the sweet corn were all measured per 14 days interval. After planting, the biomass, yield and the heavy metals concentrations of the sweet corns as well as the physiochemical properties of the soil were detected, too. The results revealed that the height, perimeter, biomass and yield of the applied plants increased by 16%-32%, 7%-34%, 26%-48% and 6%-11% comparing with the untreated control, respectively. The heavy metals concentrations in the treated soils and corns were generally far below the Environmental Quality Standard for Soils (GB15618-1995) and National Food Standards of China respectively. The benefits for this ameliorant included: firstly, it could mitigate soil acidity, the pH value of the applied soils increased by 0.2-0.5; Secondly, it could provide some nutrients to be needed for the plants: the content of organic matter, available phosphorus and available potassium in the treated soil enhanced by 2.1-3.4%, 13.79-25.86%, 2.34-13.6%, respectively; Thirdly, it could improve soil physiochemical properties: the moisture retention capacity enhanced by 2-3.92%. For this reason, the calcined product of dry and semi-dry desulfurization residue and K-feldspar will be a very promising soil ameliorant for acidic soil in South China.