ABSTRACT
Iron fixation in the central zone of Chile

Rafael Ruiz S.1 Tania Navia P.1
 

A chemical characterization of the soil and subsoil from three localities in the central zone of Chile, in which serious signs of clorosis in peaches have been detected, was done. Also, two sets of experiments were carried out, to study the Fe fixation in these soils. The soil samples were saturated with solutions containing 4, 16, 24 and 256 ppm of Fe. One set was agitated with FeSO4 and the other was left without agitation (trying to maintain conditions similar to the use of fertilizers in the field), and the Fe was applied as FeSO4 or as Fe-E DDHA. Results indicate: No presence of soluble Fe in the treated soils, at any leve! of FeSO4. When Fe - EDDHA was added, Fe fixation varied according with the soil type and concentration of Fe level. Per cent fixation decreased as the amount of Fe added increased, though the system was not completely saturated. According to the sol!, fixation varied from 40 to 83 per cent, for low concentrations, and from 18 to 72 per cent, for high concentrations. Differences between stratas of a given soil were low, though these stratas differed in levels of HCO3 and CaCO3, as well as in other fertility characteristics. The Fe D.T.P.A. index, used for annual crops, did not show a clear relation with the deficiency observed in the peach trees.

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1 Estación Experimental La Platina (INIA), Casilla 5427,Correo 3, Santiago, Chile.