2007/08/01 by Fernando Peregrina, Ignacio Mariscal, Ignacio Mariscal‐Sancho +5
Agricultural and Biological Sciences · Materials Science · Earth and Planetary Sciences · #Aluminum toxicity and tolerance in plants and animals #Clay minerals and soil interactions #Geochemistry and Elemental Analysis
paper · doi:10.1097/ss.0b013e31806db5d0
Changes in the activities of aluminum (Al), fluorine (F), and sulfate (SO42−) species in the soil solution of a plinthic Palexerult after amendment with various lime and gypsum by-products [viz. sugar foam waste (SF), phosphogypsum (PG), and red gypsum (RG)] were studied in successive extracts of the soil solution from the Ap and AB horizons, which were placed in leaching columns, over two leaching cycles equivalent to two precipitation cycles in the soil's originating area. Although SF affected mainly the Ap horizon, the gypsum amendment effects were more complex. Thus, SF decreased the activity of Al3+ and Al(OH)2+ in the soil solution from the Ap horizon. In contrast, SF affected the AB horizon, where it reduced the activity of Al3+ and significantly increased that of Al(OH)2+-only by the end of the second leaching cycle, however. Similar to SF, PG was found to affect the activities of Al3+, Al(OH)2+, and Al(OH)2+ species (particularly the first) in the soil solution from Ap; this by-product increased the activity of AlFx(3−x) ion pairs but not that of Al-SO4 pairs. On the other hand, RG significantly increased the activity of Al3+ in the first water extract from Ap and AB and also that of the AlSO4+ pair in the first four water extracts but only that of AlF2+ among Al-F pairs. The two gypsum amendments had similar effects on the AB horizon. Thus, they increased the activity of AlSO4+ and Al(SO4)2−, which peaked in the second soil-water extraction, and that of AlFx(3−x) pairs. Sugar foam waste significantly increased the Ca-Al balance in the Ap horizon, as did PG, albeit only in the first three soil-water extracts. The gypsum amendments also increased Ca-Al balance in AB, and so did SF after the second soil-water extract.