In:
Revista Brasileira de Ciência do Solo, FapUNIFESP (SciELO), Vol. 34, No. 5 ( 2010-10), p. 1535-1542
Abstract:
Organic acids can be adsorbed onto soil colloids, increasing the P availability to plants. Isotherms were used to evaluate the influence of fulvic acid (FA) on P adsorption in the clay fraction of two Rhodic Ferralsols (LVdf) and (LVd), poor crystallized natural kaolinite (KGa2), synthetic goethite (Gt) and hematite (Hm). The P adsorption isotherms adjusted to the Langmuir model in the presence of FA were suitable only for the region of low P concentration. In general, the presence of FA incubated in the studied clay fractions was able to reduce P adsorption. In the clay fraction of LVdf, P adsorption at low and high P concentrations were little influenced by the P sequence of incubation with FA. In the clay fraction of the LVd, however, the sequences of incubation with P and FA affected phosphorus adsorption. The reduction of P adsorption to the clay fraction of KGa2 at low P concentrations had no dependence on the incubation sequence of P and FA, but rather on the presence of FA. In the region of high P concentrations the incubation sequence of P and FA influenced P adsorption. P adsorption to Gt depended on the incubation sequence with FA, and previous incubation of FA reduced P adsorption. The incubation sequence of P and FA in Hm influenced P adsorption at low and high concentrations in the isotherms. The values of P adsorption were lowest under P incubation with FA or FA incubation preceded by P.
Type of Medium:
Online Resource
ISSN:
0100-0683
DOI:
10.1590/S0100-06832010000500006
Language:
Unknown
Publisher:
FapUNIFESP (SciELO)
Publication Date:
2010
detail.hit.zdb_id:
2145594-6
