Distribution and forms of iron in the vertisols of Serbia

Abstract

Soil of arable land and meadows from the Ap horizon, taken from ten different localities, were investigated for different forms of Fe, including total (HF), pseudo-total (HNO 3 ), 0.1 M HCl extractable and DTPA (diethylenetriaminepentaacetic acid)-extractable. A sequential fractional procedure was employed to separate the Fe into fractions: water soluble and exchangeable Fe (I), Fe specifically adsorbed with carbonates (II), reducibly releasable Fe in oxides (III), Fe bonded with organic matter (IV) and Fe structurally bonded in silicates (residual fraction) (V). The soil pH, cation exchange capacity, and size fractions (clay and silt) had a strongest influence on the distribution of the different forms of Fe. The different extraction methods showed similar patterns of the Fe content in arable and meadow soils. However, the DTPA iron did not correspond with the total iron, which confirms the widespread incidence of irondeficiency in vertisols is independent of the total iron in soils. The amount of exchangeable (fraction I) and specifically adsorbed (II) iron showed no dependence on its content in the other fractions, indicating low mobility of iron in vertisols. The strong positive correlation (r = 0.812 and 0.956) between the content of iron in HNO 3 and HF and its contents in the primary and secondary minerals (fraction -V) indicate a low content of plant accessible iron in the vertisol. The sequential fractional procedure was confirmed as suitable for accessing the content and availability of iron in the vertisols of Serbia.

Chemical Fractions of Iron and Manganese with Different Physico-Chemical Properties in Polyhouse Soils of Himachal Pradesh, India

“…The residual and total content were found to be highly correlated (r=0.92**) which indicates that the mobility of iron is less and that the stable residual fraction is correlated with the total iron content. The results are in accordance with the findings of Behera et al, (2009) and Jelic et al, (2011) …”

Cultivar-specific accumulation of iron, manganese, zinc and copper in winter wheat grain (Triticum aestivum L.)

“…The Fe-P interaction in plants and soil resulted in FePO 4 2H 2 O precipitation. Furthermore, P anions compete in plants for Fe-binding sites and prevent Fe uptake and translocation in plants (Jelić et al, 2011). The other treatments also showed a decrease in Fe content in wheat grains, and the values were almost identical -about 40 µg*g -1 .…”

Soil acidity and mobile aluminum status in pseudogley soils in Cacak-Kraljevo basin

“…20,21 The mean values of the total exchangeable acidity (TEA) in the tested soil profiles were 1.55, 2.33 and 3.40 meq (100 g) -1 , for the Ah, Eg and B 1 tg horizons, respectively. Al solubility increases at active soil acidities below 5.5.…”