[EN]The residual effect of five phosphatic fertilizers was evaluated on five soils and the results are compared with those obtained in a previous trial. The ´L´ value for the five soils and the ´A´ value for these soils with five fertilizers were calculated using P32. It was observed that the ´L´ value had decreased considerably in four soils when compared with those calculated in a previous trial. The decrease in the soil 2 is however less and is attributed to its differential properties. A change in ´A´ value was also observed in some soils. This value is practically null in soil 2, which possesses higher fixation capacity as compared to other soils. Phosphorus fractionation in soils containing residual fertilizers was also studied and the same has been related to fertilizer characteristics.

[ES]Se estudia el efecto residual de 5 abonos fosfatados en cinco suelos procedentes de un cultivo previo. Se determina el valor ´L´ de los suelos, y el valor ´A´ de cada suelo y abono, utilizando fósforo-32. Se observa que el valor ´L¨disminuye en cuatro suelos respecto del valor inicial, mientras que en el suelo restante (suelo 2) la disminución es menos acusada. El valor ´A´ también sufre variación, siendo prácticamente nulo en el suelo 2 que tiene mayor capacidad de fijación que el resto de los suelos. Se hace el fraccionamiento de fósforo de los suelos, y se estudia la distribución de cada fracción en relación con cada abono.

10 páginas, 4 tablas , 2 figuras

Peer reviewed