Toxicity of root-applied sulphite in Zea mays

Abstract

Zea mays was grown in nutrient solution with different concentrations of sulphite and sulphate (0, 5, and 10 mM) at pH 5 or 7, with or without aeration, for five days. Sulphite injured the plants, especially at low pH. Lack of aeration increased the sulphite injury of the plants at the high pH. in the aerated solutions, sulphite concentrations approached zero after five hours, while the unaerated solutions still contained sulphite after four days. Very little sulphite was found in the plants. The results indicate that the toxicity to the plants of the different chemical species of the sulphite in the solution decreases in the following order: SO2 (aq) > HSO3 (-) > SO3 (2-).

Ammonia-based flue gas desulphurization waste solution as a nitrogen fertilizer

“…That would give the same positive effect as split application (Andersen, 1978). The negative effect on the grass in the cuts immediately after applying the Am-FGD solution is in agreement with the toxic effect of sulphite seen in earlier experiments (Bertelsen and Gissel-Nielsen, 1987). However, the total yield of the three cuts was only lower than the control where foliar treatment of the Am-FGD solution was applied.…”

“…The present paper along with the preceding three papers on environmental effects of FGD waste products (Bertelsen and Gissel-Nielsen, 1987, 1988, and Gissel-Nielsen and Bertelsen, 1988) are based on a project supported by the Danish Ministry of Energy. The Am-FGD solution was produced and contributed by I/S Kr(iger.…”

“…Most of the flue gas desulphurization (FGD) plants are operating with calcium as the reacting agent for the SO2 absorption, and the waste products will be different mixtures of calcium sulphite and calcium sulphate containing more or less fly ash. The environmental problems with these products are discussed in three earlier papers from our laboratory (Bertelsen and Gissel-Nielsen, 1987, 1988, and Gissel-Nielsen and Bertelsen, 1988.…”

Growth of Forage Legumes and Grasses in Acidic Soil Amended with Flue Gas Desulfurization Products

“…[27] Decreases in plant growth from added CaSO 3 likely occurred because of S-SO 3 toxicity rather than from high EC, as S-SO 3 even at low levels is known to be harmful to many plants. [28] Increases in soil pH Ca and EC from the FGDs were likely because of alkalizing agents and soluble salts included in the products for stabilization. Both FGD-27 and FGD-28 had relatively high Mg ( (Table 1).…”

“…[34] Except for orchardgrass, switchgrass, and eastern gamagrass, plants grown with CaSO 3 even at low levels did not grow well and were usually dead when grown with the highest levels. S-SO 3 even at low levels is normally harmful to plants, [15,24,28,34] and caution is needed if plants are to be grown in soil amended with FGDs containing S-SO 3 . Since S-SO 3 is oxidized to S-SO 4 within relatively short time periods (days or weeks) [24,35] and if sufficient exposure to oxygen/air and time are provided, soils receiving added CaSO 3 should provide effects similar to those of CaSO 4 once S-SO 3 has been oxidized to S-SO 4 .…”