RT Journal Article SR Electronic A1 Mrvić, V. A1 Jakovljević, M. A1 Stevanović, D. A1 Čakmak, D. T1 The forms of aluminium in Stagnosols in Serbia JF Plant, Soil and Environment YR 2007 VO 53 IS 11 SP 482 OP 489 DO 10.17221/2303-PSE UL https://pse.agriculturejournals.cz/artkey/pse-200711-0003.php AB The interactive relations of Al forms and the most important characteristics of Stagnosols were researched to diagnose which factors are the best to control the content of phytotoxic Al forms. The values of exchangeable Al (Al<sub>KCl</sub>) range from 0.0 to 560.7 mg/kg and increase with depth. The variation of exchangeable Al is high and it depends on the changes of all forms of soil acidity and the degree of base cation saturation. Their relation is best described by a non-linear function. The contents of total Al and Al extracted by ammonium oxalate in dark (Al amorphous, Al<sub>oxa</sub>) increase with depth, together with the increase of the content of clay particles. The values of Al extracted by sodium citrate/dithionite (Al crystalline, Al<sub>dit</sub>), 0.5M CuCl<sub>2</sub> (Al<sub>Cu</sub>) and 0.25M EDTA (Al<sub>EDTA</sub>) are in good correlation and they predominantly depend on the parameters of soil acidity. The value of Al<sub>Cu</sub>-Al<sub>KCl</sub> (in eluvial horizons) is best represented by organically bound Al. Effects of the reserves of aluminium Al<sub>dit</sub>, Al<sub>Cu</sub> and Al<sub>EDTA</sub> on the changes of exchangeable Al are higher (medium and high correlation), while the effects of the total Al and Al<sub>oxa</sub> are lower.