PL
Oznaczono formy żelaza i cynku w glebach nawadnianych ściekami komunalnymi na polach irygowanych Wrocław — Osobowice metodą ekstrakcji sekwencyjnej według Zeiena i Bruemmera. Stwierdzono, że żelazo występuje głównie w krystalicznych formach tlenków i wodorotlenków oraz w połączeniach organicznych. Cynk związany jest w tlenkach żelaza i połączeniach organicznych, ale nawet do 47% całkowitej zawartości stanowią formy mobilne w środowisku glebowym.
EN
Zinc and iron forms were inwestigated by the sequential extraction procedure of Zeien and Bruemmer as well as some basic chemical properties of soils under long-term irrigation with municipal wastewater in Wrocław-Osobowice. Five soils irrigated with wastewater (sandy, sandy-loamy and loamy textures) and two control soils on the non-irrigated area were selected for comparison. Iron occurred mainly in the weakly soluble forms both in control soils and in soils irrigated with wastewater. The percentage of a residual fraction was lower in irrigated soils comparing to control soils, higher was however the percentage of iron occluded in the crystalline oxides (up to 77% of total Fe). Similarly increased the percentage of organically complexed iron. The most labile forms have only marginal importance (0,03-0,47% of total Fe). The percentage of zinc in a residual fraction was significantly lower in the soils irrigated with wastewater (15-40% of total Zn) comparing to control soils (up to 70% of total Zn). The percentage of zinc occluded in iron oxides 2-4 fold exceeded a content of organically complexed zinc in the irrigated soils. In spite of significant zinc binding the percentage of mobile forms is very high (up to 47% of the total Zn) in some soils continuously irrigated with wastewater