Influencia de las propiedades de algunos suelos no calcáreos en la pérdida de disponibilidad del fosfato añadido

Abstract

In ten non calcareous soils of the Asturias occident were studied the properties that more influence in the loss of availability of phosphate applied at different rates. After adding growing quantities from phosphate to a portion of soil previously depleted in phosphorus, monthly and during a period of 120 days, available phosphorus was estimated using chemical extractant Mehlich 3 (M3). The negative correlation, in the whole period of incubation, among the availability index (the proportion of added P that remained extractable according to M3 method) the aluminium and iron oxides extracted with acid oxalate and the content of organic matter indicate that the amorphous oxides present high surfaces for the phosphate adsorption. The high aluminium and iron content tied to the organic colloids increase organic matter capacity for phosphate adsorption.