Fertilizacion fosfatada prolongada y contenido de elementos traza en un argiudol tipico de La Pampa ondulada

Abstract

Several investigations have shown that the accumulation of trace elements (TE) in soils ca be accredited to phosphorus fertilization. Our objective was to evaluate the total and bioavailable content of TE on a Typic Argiudoll fertilized with diammonia phosphate for 20 years. The work was performed on the Rolling Pampas, Argentina. The treatments were: 1) pristine plot, with no history of fertilization; 2) rotation plot (alfalfa non fertilized, with fertilized corn as a predecessor) and 3) continuous corn plot, fertilized with diammonia phosphate. Total (aqua regia) and bioavailable (DTPA) TE in soils were determined with IPC. Other soil properties were also determined. The soil total micronutrient concentrations were lower in the continuous corn plot (accredited to crop exportation). The bioavailable form of Cu, Mn y Zn were higher in this treatment, and was related to soil acidification and differences in organic C. There were not evidences of changes of soil total and bioavailable heavy metal contents, linked to the continuous fertilization. Considering the present experimental conditions, the TE accumulation is not relevant.